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We're going to get started.
Our first speaker is Erin Worth.
She's with the USGS, based out of the University of Washington,
the Department of Earth and Space Sciences.
She's a geophysicist by training and she works on strong ground motions
and she's going to be talking tonight about general earthquake science here
in western Washington, the Puget Lowland, and earthquake hazards in general.
So, Erin, please come on up.
You want this microphone
here?
Can you hear me okay?
Is this good volume?
Great.
Well, thank you very much for coming tonight.
So as Brian said, I'm going to kick off the night by giving you
an overview of the different types
of earthquakes that we have here in the Pacific Northwest.
And then I'm going to try to tell you a little bit about the current research
that's being done into two types of these earthquakes.
So I'll tell you a little bit about a project that's in
its very early stages and a project that's getting towards its end.
So many of you may have seen this cartoon before.
So this is a figure that we show a lot because it does a nice job
illustrating the tectonics of the Pacific Northwest.
So the Cascadia Subduction Zone is a thousand kilometer long fault
that extends from British Columbia all the way down to northern California.
And here we have the Juan de Fuca plate
subducting beneath the North American plate.
And we're capable
of getting three different types of earthquakes in the Pacific Northwest.
So the first type are crustal earthquakes.
So these happen in response to crustal deformation.
Some of the big ones that you might have heard of
there is a Seattle fault earthquake sometime around the year 900 A.D..
There is also a large earthquake in eastern Washington in 1872.
The second type of earthquake that we often talk about
are these deep earthquakes.
So these are earthquakes that occur in the subducting Juan de Fuca plate.
And these are our most frequent types of earthquakes.
So the one you might remember is the 2001, the Nisqually earthquake.
There is also one in 1965 and then one in 1949 before that.
And then finally, the third type of earthquake
that I'm going to be talking about tonight are subduction zone earthquakes.
So these are earthquakes that occur when this red area,
this area that's outlined in red slips.
So when the subducting Juan de Fuca plate slips past the North American plate,
and these are very large earthquakes,
so generally magnitude eight or magnitude nine.
And the last one of these that occurred in the Pacific Northwest
happened in the year 1700.
And we know that
from looking at the geologic record and also from oral tribal records.
Okay.
So we know that the Cascadia Subduction Zone is capable of having
these three types of earthquakes, but how frequently do they occur?
So we generally think of these probabilities in terms
of how likely these earthquakes are to occur in the next 50 years.
So I'm in my early thirties.
I often think of this as this is the percent percent chance of one of these
earthquakes happening in my lifetime.
So for a crustal earthquake, we generally say
there's about a 15% chance of a magnitude
6.5 or above happening in the Puget Sound region.
But I am going to show you a new project later that Brian Sherrod's doing
that might be changing how we think about this number, Deep earthquakes.
Remember, I said these are our most frequent.
So we see that there's an 84% chance of one of these happening
in the next 50 years. So they're pretty common.
And finally, the subduction zone, the magnitude nine earthquakes.
So we know again, from that
geologic record that they happen roughly every 500 years or so.
So we estimate that that means there's about a 14% chance
of one of those happening in the next 50 years.
And this is about 5000 times larger in terms of energy release
than these six point fives.
So another way to think of these earthquakes
and to understand the difference between them is to look at maps
of shaking that we would expect from them.
So on the left, this is a shake map from the magnitude
6.8, 2001, the Nisqually earthquake.
So this is showing you
the areas in Washington that experienced shaking during that earthquake.
So you can see here that
a large swath of the
Puget Lowland area is kind of in this orange and yellow.
So that's very strong.
Two strong ground shaking. Okay.
And it affected.
You can even see light shaking throughout most of Washington and northern Oregon.
So if we look at this is now a hypothetical shake map.
Okay.
So we haven't seen a large earthquake on the Seattle fault in our lifetimes.
So this is what we we would estimate what it would be like.
So here you see that the there's stronger ground shaking along the fault.
So the Seattle fault is right about here where I'm pointing.
So in that area, we experience severe to violent shaking.
And then the shaking decays as you move further away.
So what about one of those magnitude nine earthquakes?
So this is a deep earthquake.
This is a crustal fault earthquake.
How did the magnitude nine earthquakes compare?
So this is a shake map for, again, a hypothetical magnitude nine earthquake.
You can now see that this red area so this severe
this violent shaking is now everywhere along the coast.
And that's because remember,
the Cascadia Megathrust extends everywhere along the coast.
And as we would expect, that shaking gets lighter as we move further inland.
And so the big difference here is that this is affecting
a much wider area than the other types of earthquakes.
So here you're experiencing
strong shaking from Canada all the way down to northern California.
Okay.
So for the remainder of this talk, I'm going to show you to talk to you
about two projects that are trying to study
crustal fault earthquakes in the Puget Sound region
and magnitude nine earthquakes on the Cascadia Mega-crust.
So as I mentioned, these Nisqually style earthquakes.
We see them more frequently.
We think we know we understand them a bit better.
We know how to prepare for them a bit better.
But for these earthquakes
that we haven't seen in our lifetime, we need to follow other
we have to look for other options to learn about them.
So we either need to look
at the geologic record or we need to maybe do supercomputer simulations.
So I'll show you a preview of what that looks like in a minute.
Okay.
So first, I'm going to talk about this project
that looks at shallow crustal earthquakes in the Puget Sound area.
And this is work that's been done by Brian Sherrard, her Chad Styron
and Stephen Inkster, the USGS.
So one of the goals of this study, which is still in its preliminary stages,
is to constrain the earthquake recurrence and magnitude
for Puget Sound area crustal earthquakes.
So this is a map showing the major Puget Sound area faults.
And this gray box here is meant to denote the region
that they're studying.
So one of the questions that they're trying to answer with
this new study is what is the estimated magnitude of previous earthquakes
that have occurred in the Puget Sound region.
So one of the things that they're doing is they're looking at fault offset.
So how much the fault has moved in the past.
And to do this, they can dig trenches across faults.
They can look at scarp profiles and they can look at
how much the earth, the paleo earthquakes, uplifted shorelines.
And so this can give them an idea for how much the fault moved.
And a lot of the estimates that they're seeing are between point five
and eight meters.
So another thing that they need to look at in order to estimate
the magnitude of these earthquakes is how long the fault is.
So recently, we now have a lot of these beautiful lighter images, which are just
a surveying technique that let you see the topography of the surface.
And you can see here there's a you can see
the for evidence of the Seattle fault.
So you can trace these faults in the lighter images
and you can estimate their length.
So the estimates that they're making in this project so far, they're seeing
are fault lines that range from 1 to 30 kilometers in the LiDAR images.
But they could be longer.
Some of these fault scarps could be difficult to see.
So using these two things, so how long the fault is
and how much they think the fault moved, they can estimate a magnitude
for what these earthquakes, how big these earthquakes were in the past.
So this image might be a little bit
hard to see, but this is showing magnitude on the bottom axis.
And these are all different
Paleo earthquake that they see in their in the geologic record.
And obviously, these humps are are the most likely magnitude
of those earthquakes.
And so they're seeing magnitude estimates for earthquakes in the Puget Sound area
that are between 6.4 and 7.5.
Okay.
So then the question becomes, how often do these earthquakes occur?
And so this image
here is showing earthquakes that they're finding.
And how how many years before present those earthquakes occurred.
And these are in thousands of years.
So this is 2000 years ago, 4000 years ago, etc..
And so these bars are color coded.
So each bar is an earthquake and the colors are color coded
to denote which fault they occurred on.
And the way to read these bars is that the center of the bar
is the most likely age for the earthquake.
And then these that tails of the bars
are possible ages, but less likely.
So if we count these up, they estimate that there's been 27
of these large earthquakes in the Puget Sound area in the past 16,000 years.
However, if you just look at the past 4000 years, so this cluster right here,
there's been about 21 earthquakes in the past 4000 years.
So the recurrence interval.
So how frequently do these earthquakes where earthquakes occur over
the past 16,000 years is 400 years.
But again, if we just look at this most recent segment,
they're happening about roughly every 200 years.
Okay.
So this is how we get the are starting to refine those estimates
for how frequently we might expect
large crustal earthquakes to occur in the Puget Sound region.
And I'm sure Brian will update you
as this work progresses in the future.
Okay.
So now I'm going to finish up by telling you a little bit about a project
that's a little bit further along to study Cascadia Megathrust Earthquakes.
So these are those large earthquakes that occur along
the Megathrust fault offshore.
So recently we had a six year, $3 million collaboration
between the University of Washington, which was NSF funded, and the U.S.
Geological Survey.
We called it the M9 project.
So M9 stands for magnitude nine earthquake.
And the
goal of the M9 project was to reduce the catastrophic potential
of Cascadia Megathrust earthquakes through advances in hazard assessment
and adaptive planning.
And I'll tell you what that means in a minute.
So this is a schematic of our M9 project.
And so my role in the project was up here.
So we ran 50 different computer simulations of magnitude
nine earthquakes that could occur in the Pacific Northwest.
So these are hypothetical earthquakes
and we really wanted to see the range of possibilities for different scenarios.
So what is the best case scenario?
What is the worst case scenario?
And then we would take those supercomputer simulations
and we pass them on to people who are studying tsunami generation
for the impact of ground shaking on buildings and infrastructure,
as well as the generation of liquefaction and landslides.
And then finally, we had some
social scientists on the project that are trying to understand and study.
How do we now present this all this information to communities
in a way that is useful to them.
So as I mentioned, we ran 50 different supercomputer
simulations of magnitude nine earthquakes.
This is an example of one of those simulations.
So you see the earthquake starts here at the hypocenter.
Seismic waves radiate out.
So the entire megathrust is going to rupture in this scenario.
Here you see, shaking has arrived at Crescent City.
These wiggles represent shaking, shaking as arrived at Portland,
Le Grand and Seattle
in a play that one more time and point out a few things.
So again, we have seismic waves radiating outwards from the hypocenter.
Seismic waves are starting to reach Portland
or just about to reach Crescent City
and Le Grand and Seattle.
And so two things that I'll point out here and then we'll talk a bit
more about the detailed results.
But one is that you'll notice Crescent City has much stronger shaking
than some of these other areas, and that's because Crescent City is on the coast.
It's a lot closer to that Megathrust fault.
Offshore, so it will experience strong ground shaking.
Now, the other interesting thing and I'm going to talk about this
in detail, you'll notice that even though Seattle and Le Grand
are the same distance inland,
so they're the same distance away from the Megathrust fault offshore Seattle
has much stronger ground shaking than Le Grand, and that's because
Seattle sits within a deep sedimentary basin that amplifies ground shaking.
So let's chat a bit more about that.
So one of the major results of this project was that local
geology is going to significantly impact the strength of your ground shaking.
So as I just mentioned, Seattle sits within a deep sedimentary basin.
One analogy that we like to use is that this is like a bowl of jello.
So if you shake the bowl of Jello because the Jell-O inside is so weak,
it'll shake much more than the bowl or the plate that it's on.
So this is just a little schematic.
Seismic waves
entering the sedimentary basin and amplifying as they enter the basin.
And it's not just the sedimentary basin, but also shallow
soft soils will also amplify your ground shaking.
So both of these things matter.
So this is just an example just to show you
about how shallow soft soils will amplify ground shaking.
So this is a figure from Kathy Troost at the University of Washington.
And this map here is showing in the colored areas
the thickness of artificial fill or Holocene, Alluvium, sediments.
So this is very weak material and so in addition to being in the basin
and having the basin amplify your ground shaking, these areas will also have more
amplification on top of that because of their shallow soft soils.
Okay, so this is a geologic map of Washington,
and I don't expect you to be able to see all these different things.
But I just want to point out this this yellow color here is a sediment.
So the Puget Lowland,
even though not everywhere in the Puget Lowlands, is in a deep sedimentary basin
like Seattle is, it still has some sedimentary material at the surface.
And so this is going to amplify ground shaking in that entire area.
So I'm going to in a minute zoom
in on one of our supercomputer simulations in this region.
But first, I just want to point out, so this is the Puget Lowland wheat.
I just said we have sedimentary
material at the surface, but then we also have these deep basins.
So this map here, I know it's a little hard to orient yourself.
Seattle is right around here and everywhere that you see Dark Blue is
or most places that you see, dark blue is a sedimentary basin.
So there's a basin beneath Everett, there's a basin beneath Seattle,
there's a basin beneath Tacoma.
So everywhere. Okay.
So this is
this is one of the results from our M9 project's supercomputer simulations.
So this is showing long period shaking that's going to impact tall buildings.
And so what I'm showing you here is shaking intensity at a period of three,
3 seconds.
So this is a shaking that would impact maybe a thirty story buildings
a fairly long period.
So every where you see red color is stronger, shaking.
Everywhere you see light color is weaker shaking.
And you can see that the entire Puget Lowland is lighting up compared to areas
that are not in the Puget Lowlands or areas on the Olympic Peninsula are white.
And the Seattle Basin and the Tacoma Basin are lighting up even the most.
And that's because of those deep sedimentary basins.
Okay.
So the second outcome of this magnitude nine project
is that there are a range of possibilities.
Okay.
So I mentioned we ran 50 different computer simulations
and there is a wide range of shaking intensities.
And so part of the
reason for this was because we varied a number of different rupture parameters.
So we when we ran these supercomputer
simulations, we varied the hypocenter location.
So that's where the earthquake starts.
So sometimes we had it start in the north, sometimes we had it start in the south,
sometimes we had it start in the middle.
We also varied the inland rupture extent,
so that's how close the rupture gets to Seattle.
And finally, we also varied the location of these strong patches on the fault.
So there are certain patches on the fault that seem to radiate
the strongest ground shaking and so their location matters.
So we also varied that.
So I given that I don't have a ton of time,
I'm just going to show you an example of what happens when we bury the hypocenter.
So where the earthquake starts
and so this is the most technical I'm going to get.
So bear with me for a second.
But the reason why this hypocenter location matters
is because of something called rupture directivity.
So rupture directivity refers to a phenomena where earthquake ground
shaking is strongest in the direction of fault rupture.
So you can kind of think of this like a Doppler effect.
You know how an ambulance sounds different
when it's coming towards you versus when it's going away from you.
That's similar to what's happening here.
So I tried to draw you a schematic.
So this black line here is a fault.
Let's say the fault, an earthquake starts
on the fault at this yellow star.
And then I'm going to say the fault is unzipping in this direction.
So towards the right.
So that means that anything in front of that direction,
so towards the right, will experience stronger shaking as these seismic waves
pile up on their way in that direction.
An area is behind the unzipping of the fault will experience weaker shaking.
So let's look at two
different magnitude nine earthquake scenarios.
So first scenario a so everywhere.
So this is I should explain this first.
So everywhere you see color is a spot on the megathrust fault that's going to move.
Okay.
And it's going to the hypocenter location is where this star is.
So the earthquake will start here for this scenario.
And then it'll unzip in all these directions.
So to the south, to the west, to the north.
But it's you'll notice that it's going to be directed
away from Seattle.
So for scenario B, so this is they're both magnitude nine earthquakes,
but in this case, the hypocenter starts pretty far offshore.
So it's going and it's also to the south.
So that earthquake rupture is going to unzip to the north, to the east
and to the south.
So you'll notice now that it's unzipping in the direction towards Seattle.
So let's look at what the ground shaking would look like in each
of these scenarios.
Oops. Okay.
So this is for shaking, recorded, hypothetically
recorded at a site in Seattle.
So this is the velocity of the ground shaking over time.
And these are both to the same scale.
So both magnitude nine earthquakes to the same scale, same location in Seattle.
But you'll notice the shaking in this scenario is about four times greater
just because we changed where the earthquake starts.
So where are the earthquakes starts makes a big difference
in terms of the ground shaking.
You might experience.
So I do want to briefly touched on other parts of the project.
So I did mention I'm a seismologist.
I worked on these super computer simulations, but there are a lot of
a lot of other pieces to that M9 project that are also happening.
So we have some folks at the University of Washington
that are now taking our hypothetical ground motions
and they're putting them through their building models.
This is this is exaggerated to see,
you know,
we also have people that are looking at the potential for landslides.
So they look at the slopes that already exist in Seattle
and then they take into account the ground shaking
that we're predicting and everywhere you see color here.
So it's me.
This is West Seattle. This is where I live.
So everywhere you see color.
So on these steep slopes are areas where they would predict landslide
landslides to be likely.
We also have people that are doing tsunami simulations.
So as we know from the 2011 Tohoku earthquake in the 2004 Sumatra earthquake,
the tsunami is often has the greatest impact on loss of life.
So we also have people that are doing simulations
of tsunami generation and inundation.
And then finally, I did mention that we have some social scientists
on the project.
So they're taking some of their results.
And this is an example where they're taking some tsunami simulations
to local communities.
So this is a workshop that they had in Aberdeen, Washington,
to try to show the communities these different possible outcomes
and discuss community planning for future.
Okay. And I so I'm done.
I think we're going to hold questions to the end, but thank you very much.
you going
okay? Thank you, Erin.
That was great.
Yeah, it's going to queue up our next talk.
You can probably hear me.
Okay. Well, I'll speaking to this microphone.
So our next speaker is Harold Tobin.
Again, He's the state seismologist.
He's based at the University of Washington and he's a geologist slash geophysicist.
You guys, he couldn't make his mind up.
And again, he's based at the seismology lab
at Earth and Space Sciences at UW.
And I do want to mention that he's recently come to us
from the University of Wisconsin,
and I was teasing him earlier that he's finally come to the real UW.
Okay.
And Harold is going to talk to us about monitoring and including
seismic monitoring in the Pacific Northwest, including the New Earth,
the planned
earthquake early warning system that they're building out here in the Northwest
Herald.
Thank you.
But of course, it's not true.
I came to the real U Dub and the other one is UW.
And that's the difference.
Yeah,
but yeah, I'm actually really happy to be in Seattle and so happy
that all of you come out tonight to listen to us talk about these things.
I'm going to take a step back from now
that Erin has kind of scared you about a lot of the potential scenarios
and take a big picture, look at the subduction zone
and then and then segue that
into talking about earthquake early warning, as Brian just said.
So, you know, we literally inhabit the subduction zone.
Right.
And it is the thing that makes this place a beautiful place to live. And
we live in the shadow
literally sometimes of volcanoes that are directly related to the existence
of the plate tectonics system, the activity of the subduction zone.
We can look out the other way from the city
and see the Olympic Mountains.
And if you take a perspective on the Olympics, you know, from offshore,
looking in towards towards the coastline,
actually, I got my start as a as a researcher in this field,
as an undergraduate field assistant to one of my profs, working
two summers in the Olympics, spending 35-40 days in the backcountry
up there, high up in the mountains.
Those mountains are literally there, you know, because of tens
of thousands, hundreds of thousands, millions of earthquakes that have slowly
uplifted them.
Earthquake by earthquake by earthquake.
And maybe that's a daunting thought in a way.
But to me, it's just says that we choose this place to live
or we are here in part because the earth is so alive in our region.
And that's something to to both embrace and recognize the natural hazard from.
And when we look at a view like this,
we can recognize, too, that the system is something that affects us on land,
but as equally sort of complex and interesting geology offshore.
And you look out there and hopefully I can figure out
which one of these buttons is the is the laser, maybe that one.
There we go.
You look out there and you can see all these
maybe these sort of lines or these things that look like worms marching northward.
And they're literally like the folds in the carpet, meaning the
the Juan de Fuca plate that's going down underneath our feet.
You know, look down 30 miles straight down. Right.
Is that subducted
thing that used to be the seafloor of the Pacific Ocean off our coast,
but as transferred underneath underneath our feet in the North
American continental plate.
And it it folds up to the layers of sediment and scrapes them off
that we're sitting out here on top of the subduction zone,
the part that Erin has just told you about where the fault zone is,
is actually underlies all of this region, mostly offshore, a little bit on shore.
But an awful lot of that fault is actually the offshore part.
So we literally inhabit the subduction zone.
Of course, that comes with this cost and we've already talked a little bit
about these earthquakes and the deep slab earthquakes, the ones that are down there
in that chunk of the former sea floor of the Pacific Ocean
that's below our feet are the ones that were most likely to experience
in the future, as Erin just showed you and we've experienced in the past.
And, you know, 2001 was 18 years ago, the last really strongly felt
earthquake course.
We had a little reminder this summer
how many people were woken up by the by the 4.6 in Morro in July?
Yeah, I was
I had just gotten off a plane in Japan for a research meeting over there.
So my my phone started buzzing like crazy with the news
media and stuff, asking me questions.
And I was sort of having
dinner in a beer in Japan, so I couldn't answer very, very directly.
But but our region is an earthquake prone region.
And so I'm going to show you just basically the summation
of 40 years of the data that the Pacific Northwest Seismic network
has collected was actually this beautiful visualization was created
by our fantastic colleague Nathan Becker at the Tsunami Warning Center.
But it's going to show you our region dates are going by up here in the corner.
So there's 1980. We're just going month by month.
The size of the circles is by scale, by how big the earthquakes are.
You can see the scaling right there. Right.
And then they're just going to appear and then they're going to slowly fade away
and depth is the color.
So you can see bigger earthquakes and little ones.
And we constantly have earthquakes in our region.
There are tens of thousands of earthquakes
over what we call our earthquake catalog.
And they also occur in patterns that we recognize as specific areas.
So offshore, actually, we see a lot of earthquakes
at the kind of the southern end and northern end of this one,
the Fuca plate,
where it kind of meets a couple of other plates
and they're breaking up and jostling at their edges.
And then we also see them along what's called the Blanco
transform fault, a strike slip fault, much like the San Andreas down here,
Northern California, southern Oregon had a lot pop off in the 1990s.
But meanwhile, we're seeing a kind of a constant background.
Of course, we don't feel the vast majority of these earthquakes
that happen in the Puget Sound region.
Oregon's pretty lucky. It just stays really well.
Oregon's pretty boring is another way, I'll put it to a seismologist.
But it you know, it has a lot less going on down there.
And what I'm going to do is actually jump this ahead a little bit.
There's so much interesting stuff in all the time that's available.
The question is, can.
I get the mouse to talk to me or not?
Maybe I can't.
Maybe I can't see it well enough to it's down there.
But okay.
So that was Nisqually, right?
December 2001 and it's close enough now.
We'll let it we'll let it run out a little bit.
So our main locus of earthquakes are actually those crustal
or slab earthquakes right under the Puget Sound region.
And that's why a lot of the concentrated monitoring has been there,
These distant offshore ones, even though they're pretty large
and pretty frequent, really don't present a hazard on shore.
They're not tsunami sources and they're also too far away
to create a lot of shaking onshore from these events out here.
Now, notice what's missing, Right?
We just don't see anything in that part where Erin just told us
was the potential magnitude nine earthquake all in that area.
We see it all filling in further in underneath our feet
or much further offshore,
but not in the part that we think of as this critical megathrust zone.
So I'll call that the dog that hasn't barked in the night.
Right.
In the entire time we've been recording earthquakes,
there's been barely anything at all.
Even down at low magnitude levels.
On the Cascadia Subduction Zone. Erin
already told you about the probabilities, so I won't go over that now.
But we know that it is actually locked up and ready to produce
the next earthquake for a number of reasons.
And one is we can actually literally measure the way the strain
is accumulating in the crust using very sophisticated GPS measurements
and other things that tell us how the two plates are locked together.
But also, we know that there is this event in in 1700.
And if you've you've probably heard this story already
because you're all here because you're interested, at least in the earthquakes.
But, you know, that's the best piece of geo sleuthing, I think, of all time.
Basically, that Brian Atwater from USGS here in Seattle
at UW, David Yamaguchi, Kenji Sataki and others did together.
And, you know, they knew that
there were the legends from the indigenous native tribes along the coast that some
that big events had happened, flooding villages and strong shaking.
They discovered that there were all kinds of deposits that came from
the actual tsunami in the coastal regions over the top of topsoil.
Suddenly both sand's that came from the tsunami and then
mud on top that showed that the land had been dropped down
and in fact killed all the trees.
All of a sudden in these ghost forests and the tree ring dating showed
not only the year that that took place, but even the season, the winter time.
But we know it even better than that
because the groups, the historians in Japan were aware of this
tsunami that had no earthquake associated with it,
the ghost tsunami or the orphan tsunami of that year, 1700.
And there were lots and lots of very detailed
historical accounts of the damage done by a tsunami with no known earthquake
and by computer simulations of what
it would have taken to inundate the Japanese coast exactly that way.
The conclusion was drawn that only a magnitude nine earthquake
coming from this portion, the Pacific Northwest region of of
the northern Pacific could have produced the tsunami that accounts for all of that.
So it actually gives us the date and the time,
you know, literally down to the individual day.
And any
people in the room would know about this will know that I have a typo on there.
I can't believe I forgot to fix that since the last time I used that slide.
January 26th is the correct day. Right?
So our region is an earthquake region and we know it.
And so, you know, when you think about earthquakes, they don't happen very often.
So we don't think about the losses from them all that often.
But this is a FEMA's estimate of the annualized meaning.
If you average out even things that don't happen for decades and decades, the cost
associated with them, you get really significant numbers.
Most of the earthquake hazard for the U.S.
is on the West Coast.
A large, large fraction of that is in California,
but something like 700 million per year
when you average out earthquake losses over time is in our region up here.
So we really have to be be thinking about all of this
and thinking about what can we do to mitigate it.
And, you know, my argument, of course, as a person who works on this
is that we don't spend nearly enough money on all sorts of mitigation
because the annualized costs potentially are so large.
So that's led to the work of the Pacific Northwest Seismic Network.
And my predecessors here, you heard I just got here a year ago,
so I can't claim much credit
for the PNS and Paul Boden, who's the network manager for PNS and is here now.
Steve Malone, who's the former director of the PNS
and was famous for warning all of you about Mount St Helens back in 1980,
did a lot to make this happen.
We now have hundreds of seismic stations that are contributing data
all the time, real time data feeding into our computers
and to our network at UW and allowing us to rapidly calculate
how big an earthquake was, where it's located,
how it might be aligned with particular faults
or parts of the plate tectonics system that we do or don't know about.
And now also allows us to do this kind of
not just fast, but even real time earthquake.
Early warning that I'll tell you about in a minute.
And our hosts tonight, the USGS, our our our big funding source at U Dub
so we can operate this this seismic network.
We're in our 50 year anniversary right now in 2019.
So, you know, our mission is reducing the impacts of earthquakes,
interruptions by providing the information.
And that's one component of that is what we're doing right now.
Right.
And our job is also to to to monitor ground motions.
And ultimately now a big thing that's become kind of the exciting new thing.
And also the the the the big activity for us in recent years
and right now is operating this ShakeAlert earthquake early warning system.
So I'll talk a little bit about what earthquakes are, because to understand
earthquake early warning, we have to think about this.
We experienced an earthquake, a shaking, right.
The ground is shaking for us and that's what we feel.
But the earthquake itself is there and just kind of really made up.
Very obvious is the slip that happens on the fault.
So as the two sides of the fault that are storing up that that strain
their frictional is stuck together,
just like in if you have a heavy piece of furniture
that you can't push across the floor
because of the friction holding it down the floor.
But when the stresses that accumulate from plate tectonics,
from the push of the plates overcomes that, it breaks
and it slips along this kind of rough surface,
it's really hard to point from these these high angles over.
Here, or maybe the. Pointers just dying on me, but
it slips along that rough surface.
And as it chatters along, it's radiating those seismic waves just like noise.
You know, when you push that piece of furniture
and something goes across the floor, the seismic waves are something like that.
Unlike sound waves, seismic waves radiate in a couple of different modes.
And so there's what we call the P waves and the S waves P for primary or first and
and S for secondary, and then the surface waves that follow them.
And this thing called PGA means peak ground acceleration.
So the part of the the the shaking that has the highest amplitude
and does the most damage.
The key thing for us
that we'll see in a few minutes is that those P waves come first
and they tend not to be damaging, but they get to a sensor very quickly
and they're followed by these much slower but more damaging waves
that come later.
All right.
So zooming back out, then, we can say, well,
these subduction zones are not just the Pacific Northwest.
They're actually lots of places around the world.
That's a partial list.
And they all share some common features.
So now we kind of understand
that that plate that's coming in is going down beneath our feet.
Eventually, when it gets quite deep,
it's so deep that it starts the melting process that fuels our volcanoes.
So, you know, we have the subduction process to thank for all of the volcanoes
that we that we enjoy being near and also worry about a different hazard.
We're not talking about tonight. Right.
But the part that's shallower is not so hot and so it's colder.
And that's where the plates can get stuck together.
And ultimately create that earthquake that then ruptures out
and along the the subduction zone and crucially,
takes this portion that was stuck together and sort of pulled back
almost like an archer pulling a bow back
for the hundreds of years in between earthquakes.
Right.
Accumulating that strain at a rate of just a couple of inches
a year about the rate your fingernails grow is is a way to think about it.
So let your fingernails grow for 300, 400 years and you've got many,
many tens of feet, you know, dozens of feet of accumulated missing slip.
And all of a sudden that goes.
And when that displaces the sea bottom, it also is the thing
that launches the tsunami, that's pushes the water up in exactly the same way.
It pushes the sea bottom up and then the tsunami goes.
So that's the geology 101 portion of this evening.
Right there is the
the diagram, the uplift of the sea bed is the cause of the tsunami.
And we know, of course, that for subduction zone earthquakes,
in our experience, the tsunamis are almost always actually when they're generated
at least the largest hazard from the subduction earthquake.
And that was probably true in 1700 for the people who lived along the coast.
That's a photo from Tohoku, Japan, in in March 2011 during that very large tsunami.
And it was you know, it was a shocking moment for all of us.
Right.
Seeing all that stuff, especially the live footage
that was coming in on television and everything at that time.
But I want to not just say this.
These are events are so overwhelming.
And I think a lot of people read that New Yorker
article just thought there's so overwhelming.
There's nothing we can do about them. Everything's gone.
Everything west of I-5 will be toast, is the quote from the New Yorker article.
And it's actually kind of a misquote anyway,
because what FEMA was really trying to say was everything we have to plan
as if everything west of I-5 could be toast or anything west of I-5.
And they didn't even mean I-5.
They really meant west of the Puget Sound Puget Lowlands region.
But, you know, to think about
how all of this happens is to recognize that in this disaster,
which is one of the hugest subduction zone earthquake disasters, 19,000
people lost their lives, virtually
all of them, by the way, from the tsunami and not from the earthquake.
And that's partly because of excellent preparedness in Japan, building codes
and in life safety structures.
So earthquakes, subduction zone earthquakes are eminently survivable.
Right.
And even the tsunami, you can look at it a couple of different ways.
19,000 people lost their lives at the moment of the earthquake.
350,000 people were the death zone of the tsunami.
So that means 94% of the people escaped and 6% were killed.
It's a terrible disaster and I wouldn't want to minimize that at all.
But again, it means that these things are things we can prepare for
and are potentially very survivable for the vast majority of us.
The potential loss of life in a Cascadia scenario, even in some of the worst case
scenarios, is only a very, very tiny fraction of the population.
Many of us will be very inconvenienced by the damage
that comes from the earthquake.
But I don't want people to think of it
as something that's not worth thinking, thinking too hard about.
So in the frame of talking about things that we're thinking about,
then one and it's one of many ways to prepare for earthquakes.
We're going to hear a lot from
from the next two speakers about other forms of preparation.
But one is we've recognized through the USGS and it's university
partners, which includes us, but also Oregon, Berkeley and Caltech, that there's
a capability, a technological capability to warn people before
the shaking gets to them, in many, many cases for earthquakes
and for tsunamis, for that matter, and that we can use that information
to help to help protect people and save lives.
So that's led to this this system called Shakealert earthquake early warning.
And it takes advantage of the fact that there are all of these
seismic stations are as are these pink ones up here at the points in.
But then California is loaded with them as well, of course, and there's even
a little bit of offshore instrumentation and use all of those stations
to detect those P waves and warn people before those damaging S waves get to them.
I'll show a little animation of that in a second.
So actually, Shakealert is here in the sense
that we are already operating the system.
We're using it in a pilot mode now even in our region, and have some pilot
infrastructure collaborators who are using it to do real things
to protect infrastructure now and full scale public alerting,
meaning via an alert they would come to your phone through the
the the we as system the like Amber Alert style system
or an app just went live in California two weeks ago.
There's Governor Newsom announcing it
and we're moving to public alerting in Washington and probably in Oregon
in October 2020 is the goal that the State Emergency Management division
has set out in that we're full partners on a with with that.
So there are some of the examples, the direct emergency alerts
which are which are now potentially taking place.
That's the way everybody thinks of it, potentially happening.
There's two issues with those direct emergency alerts.
One is that they only can show you a very simple message.
The technology is just a text message like this.
And the second is that because of just design of that system
and actually in part for some very good reasons,
there are built in latencies and delays that are hard to overcome.
It's no big deal for an Amber Alert to have it
get to your phone 20 or 30 seconds after the alert.
But for an earthquake that could be getting the alert
after the earthquake hits you instead of before the earthquake hits you.
So people are working hard on that problem, but also working on releasing
these these apps that you instead download, which have at least the promise
of reducing some of that latency and giving us more information
during and after, crucially, after the earthquake, like Shakealert, L.A.
and this other one up here called my Shake.
All right, so how does earthquake early warning really work?
And the key thing is that it's not prediction of the earthquake.
It's just detecting the earthquake as soon as it happens.
So there's the earthquake in the subsurface.
It starts it starts radiating waves.
Those first ones are the P waves.
The the red pink ones behind them are the S waves.
So the P waves start passing some of the seismic stations, which can
then immediately transfer their information over our tele
meter data or our internet connections back to u dub or the other centers
within approximately, you know, numbers like a couple of seconds.
The location of the earthquake and a rough estimate
of the initial magnitude is done
and then it's determined whether an alert should be sent out.
Beam the alert out and then, yeah, hopefully that doesn't happen, but
at least not quite like that.
But but before the damaging waves get there.
So that's the fundamental principle behind it.
And we've got lots of examples of ones that have been caught
during our whole development and testing phase.
This is just one where an earthquake took place up there by Astoria
and there was a first alert issued just a few seconds
after less than 2 seconds following the P wave arrival to the surface.
And so that led left 24 seconds to warn
people in the Portland region of potential earthquake.
The Monroe earthquake was close to Seattle.
That was a tougher one to do with a lot of advance warning.
But our system generated a warning with about
I think it's eight and a half seconds
of potential advance warning, not a lot of time,
but enough time to mentally prepare and do some of your activities,
like drop, cover and hold on.
And I'll show you something interesting about that in just a second.
Here's
another rupture simulation for a magnitude nine earthquake by a different group
using some of the same kinds of simulations that Erin just showed you
at San Diego State.
It's again showing you a big magnitude nine earthquake.
And you can actually see the effects of the directivity
that you all are experts on.
Now that that Erin, just showed us, as well as some of the concentration
of seismic waves in the softer rock off shore.
But if you look at the time scale, I know it's tiny down here
that 2 minutes have already passed since the earthquake started.
And by the time the waves get to Seattle, it's going to be more
in the order of 3 minutes plus down here on this time scale.
And so what it suggests is that for at least some of those scenarios,
there's a potential to detect it as soon as the waves come ashore
and then still have significantly longer amounts of lead time
in the Puget Sound region.
If it's closer in directly offshore, then it's more like in the 30
to 40 seconds or 40 to 50 seconds kind of timeframe.
But still significant amounts of time.
So different earthquakes give us different different responses.
Much more similar to the. Mexico.
I want to show you this video.
I was actually a graduate. At 5:04 p.m..
So American Studies. One was underway at.
UC San Diego grad school three weeks at the moment of the Loma Prieta earthquake
30 years ago.
And here's a classroom.
I was probably just about two blocks away from this classroom.
Students just figured out.
An earthquake was happening
and didn't drop coverage.
Everybody got up, stuff all falling from the ceiling.
Nobody should get in.
The hallway during an earthquake and nobody should try to exit the room.
It's the falling stuff that's going to hit that's going to hurt you with.
The video cameras everywhere.
This was the this was the most visible earthquake.
Ever footage in all of this kind of real time.
I mean, real data showing showing what it was like during the earthquake.
Poor kid. I know.
And then, of course, we all know it as the series earthquake and the TV ended.
And that was, you know what a lot of people heard?
No, I was right on top of that earthquake and the power was out
and we didn't even know
how large an earthquake it was until somebody came by in a car
with the radio on.
So the Bay Bridge just collapsed.
And and that was the realization.
So I just showed you some really graphic examples, you know, falling hazards.
Whoops. Let me go back.
There are very well, I went the wrong way and it doesn't want to go back.
There we go.
And the injuries are linked to falls.
And the same goes for the Northridge 1994 earthquake. So
the cost is really high.
And even just being able to prevent a significant fraction of those,
there's an opportunity to really save a lot.
So just as a contrast, this is Anchorage.
There was no earthquake. Early warning.
Watch from when these kids notice the earthquake is starting.
They're all under the desk.
Within less than 4 seconds. But
to do what you're actually
automated control of systems.
I'll skip over that.
I do want to kind of talk about this just a little bit.
Shakealert Earthquake early warning system is an expensive thing.
Putting all of this together, there's an estimate
that the capital investment to make it is about $40 million total,
but it'll still cost us about 28 million to operate it annually.
So I think in our region it's good to put that in some units
that we can actually relate to because
big numbers, $28 million sounds like a lot of money.
Right?
But let's think about, you know, something useful to the city of Seattle.
And so I like to define a unit as one.
Wilson Famously, he makes $35 million a year
to play football now, so the cost is about 0.8.
Wilson units per year, right?
Not bad.
Okay. The last thing I'll talk about is this.
If you bear with me for for two slides, is to say that the final frontier for us
is really moving offshore to the locked up fault zone is out.
There are sensors are all on land.
That's not good.
That's like sort of, you know, the light is over here.
But I lost my keys over there, so how do I look for my keys?
So there are already some offshore
scientific sensor
cables that are exist both in Canada and in the U.S.
And there are a few of those seismometers that are starting to be on the sea floor
that can feed data back.
But we need a lot more of that kind of information.
And there's been a lot of work go into trying to determine
what sort of earthquake early warning we could do.
And we're looking right now at adding a lot of seismic detection systems
and other things to this region off Oregon, where the cable already exists.
We'd love to see that go a lot further.
So just to sum up, there are real concern, right?
But we prepare not to spare.
I think that's one of my key messages.
And early warning is on the cusp of reality here and we want to integrate it.
And it's an end, not an order. Right.
And and not a nor with regard to other resilience efforts.
This doesn't replace preparedness.
Thanks very much. Thank you
very much.
Yeah.
So, again, we're going to do questions at the end
and Erin is going to queue up our next talk.
So our next speaker is John Hooper, and John is a senior principal
and director of earthquake engineering at Magnusson Klemencic Associates.
That's here in Seattle.
He is.
We've had a long working relationship with John, probably 25 years now.
And he takes our stuff and really puts it in action
and puts it to use and puts it
into the designs of buildings here that we live in and work in every day.
And so his work is extremely important, very valuable.
And so John is going to talk to us about the engineering
and the built environment here in the Pacific Northwest.
Appreciate it. Pleasure to be here. Thank you for that.
And built environment relative to earthquakes,
because that's what we're talking about here tonight.
And actually, we go back over 30 years to 1988
when I first met
Brian Atwater, when he described to me the subduction zone earthquake for which
I didn't believe him for about a year or two, he convinced me at the very end
I want to talk to you, those about the history of code development
kind of give you a sense of our building
stock here in the Puget Sound area and what you can expect from it,
not just new brand new towers that have been designed in the last 5 to 10 years.
But the stuff that's been around here for over 100 years and we've been trying
to deal with this phenomena of earthquakes for about this hundred year.
What we're trying to do is provide
guidance for engineers like me and others in the Puget Sound area design
that are simple, economical and reliable
to protect life, safety to protect us as individuals.
Property is on there, but property isn't our major focus at this time.
It hasn't been easy to make these changes because we have to wait.
Generally speaking,
for the most part of this hundred years for earthquakes to tell us what works
and what doesn't.
So you have to learn from that because that's Mother
Nature is the best teacher of all, and it's not even close to perfect yet.
We heard about this new information about the crustal events
I just heard for the first time tonight, the magnitude is a lot higher.
I've heard about it before, but the magnitude is higher.
End of the term period is shorter.
That changes the dynamic of what we should do in building design.
So I would take kind of a walk through earthquake engineering history
and what we've learned and by and large, the majority of what we learned
is from California, don't despair, California is a good state.
We like them, They're good.
But we work hand in hand with the state of California.
And so what they learn in California.
Oh, yeah, sorry.
We we use here in the Puget Sound area.
So these lessons are very germane to what we do.
We all heard about the 1906 San Francisco earthquake.
Interestingly enough, nothing became of it in the design of buildings
in San Francisco following that event, a missed opportunity.
They may have been working out, but nothing really happened until 1927.
That was the first building code that was formulated that governed
design of buildings made mainly in the Western United States.
And within that document they did have earthquake information and requirements,
but in what is called a non mandatory appendix mean you could do it or not.
It depended on you, the engineer, or the jurisdiction that was adopting
this building code for use of designing, constructing buildings.
But if you did do it and you did know about earthquakes, you see the word there,
earthquake shaking is moot, meaning if this happens, you should design for it.
And they gave some information to the engineering
colleagues back in the time of what to do.
But again, it wasn't uniformly done
throughout the western United States back in 27.
The next big event that really changed a lot is in 1933
Long Beach earthquake.
It made a lot of changes in California that permeated its way up here
very quickly.
They made a bunch of legal changes
when they're called the Field Act in California, very famous for them.
It banned unreinforced masonry buildings.
Those unreinforced masonry buildings still exist.
The Puget Sound area,
you see a lot of them in small towns around us, a lot in Pioneer Square.
We adopted that same ban not 1933, but in by the 1940s.
We said, you can't build out of this material
because you see response in buildings like that.
They also did something called a Riley Act,
which basically said we need to design for earthquakes to a certain amount
of force, how much the earthquake is going to try to push your building sideways
due to the ground shaking underneath it.
And so that was developed back in 1933.
We still use that same number today throughout the United States.
Interesting that we use the same minimum force.
It can't be anything less than this
in any building design, anywhere in high seismic.
And as you know now we are high seismic.
The next seminal event was in 1971 San Fernando Earthquake.
So remember, you saw other
pointing out to the events that we had here in the Puget Sound
area, the 49 and the 65.
We were very clearly understanding that we had earthquakes happening here.
We knew they were probably different than California because we can't see
something called the San Andreas Fault, which you can actually see and walk over
so that we were doing the right things consistent of California.
So when this happened, we knew that this kind of thing
would be expected up here in the Puget Sound area as well.
What did we learn?
Pretty simple. Don't build on a fault.
Two things happened.
They created the Alquist
Arriola Act in California, which mandated that you could not build on the fault.
And the building code itself, about 25 years later did the same thing.
If you have a fault and you know it,
some of these faults are hidden faults,
so you don't necessarily know where they're at.
You can't build there.
walls must be tied to the roofs and the floors.
Boy, that sounds like a good idea.
Why would you stack a bunch of walls and put a bit of roof on it
so it gets fall right off? It makes no sense.
We were doing that back in the sixties and fifties and beforehand.
Yeah. Oh, I learned lesson the hard way.
There's a term I would talk to you about called non ductile concrete.
This is concrete buildings that don't have sufficient amount of rebar
reinforcing steel within them and the right orientation that reinforcing
steel is from this earthquake that we really started pushing in fact,
that concrete itself is not a bad material.
It's its interaction with the reinforcing steel that is inside of it.
And how it all connects together wasn't being done very well.
And so if you think about that, what about by the mid 1970s?
We kind of we think we kind of solved the problem.
We never really saw what we think we do anything built before then.
This concrete, maybe not a good maybe not a good thing, maybe not a good thing.
And finally, some structure more important than others.
What that means is we understood that if you're a hospital, you're design
objective for seismic performance should be higher because that's
what people go when they're hurt versus just a residents.
You could argue that shouldn't be the case,
but we separated performance between what we call essential facilities
and ordinary occupancies like we are in here today,
1985, Mexico City, big buildings fell down 15 to 20
story buildings fell down like this.
The Pino Suarez, this a detail for really engineering nerdy guys
in the audience still columns collapsed
because they weren't strong enough and so we fixed that in the building code
so that we don't have that problem anymore.
Again, Mother Nature is really describing what we should do,
and she tells it to us very well.
And buildings that are next to each other, that can be a problem.
They pound, they hit and they cause damage and potentially collapse
where they hit together.
And we changed our requirements because of this earthquake, how far apart
or how close two buildings can be built to each other.
Before that time, we didn't have rules for that.
So if think about buildings around here that are very close together
as you walk by them, think about that or not.
It's your choice.
I think about it way too much. Obviously.
1994 Northridge earthquake.
It showed us the best system
that we thought we knew about was what we call steel frames.
They cracked steel can crack.
This is about
this. This doesn't work anymore.
Just like that's planned.
You see it right here.
That's three inches thick of solid steel, cracked, wide open.
And that happened in numerous buildings in in this earthquake.
She had to develop a whole new way to doing steel buildings.
And then so anything built before 1994
has a potential for looking like that.
This is a tougher slide to see.
These are what we call tilt up buildings.
They are basically concrete wall buildings that they actually build
a concrete on the ground and they tilt them up
and they make warehouses out of them.
You think about the Kent Valley and all those warehouses like that before
1984, the separation between those walls and roofs, they separate way too much.
And we lost 200 of them in that earthquake.
So we improve that connection to make them stronger than we had
previously to help mitigate that from happening.
So that's kind of the history lesson through time.
And I just pick the top four or five events.
I want to really emphasize what we've already heard tonight and,
what benefits we've had this interaction with the USGS over this timeframe.
You've seen this this slide before.
I want to say what this means to the engineering in the built environment.
Well, we recognize a cascade subduction zone.
In that late
1980s.
Again, Brian Atwater came in, the USGS colleagues to the Structural
Engineers Association of Washington and says, I think we have a problem.
And we sat down for several years and try to figure out how big of a problem
it was.
And by by about 1992, we changed our building codes to account
for this shaking, a collaboration that goes back to that, that time frame
recognition of the shallow fault.
We knew that we had shallow crustal fault,
but we didn't really know the size and the recurrence, etc.
We now know it's even worse.
Thanks thinks that the research that's going on at USGS.
Thank you, Brian.
I don't want to talk to him anymore.
And so, again, that will change what we do in the future.
It'll take some time.
You'll take five or eight years.
It doesn't happen overnight,
but it's good to have this collaboration to help solve these problems together.
And then finally, the recognition of the Seattle Basin.
You saw the the examples that Erin showed about those simulations.
We knew about them, but probably a little bit before this,
we started to incorporate them into our tall building designs about 2010.
Not exactly the way it's being done now, but we would recognize it.
We try to think about it
and try to make sure our tall buildings accounted for this in some degree.
And I'll show you a little.
A little.
Video here at the end of the session tonight.
I do want to talk about about the fact that when we design buildings, I'm
not sure you're aware this that we have to follow building codes and standards.
The building code is adopted by the state of Washington, for instance.
It becomes law is something we engineers have to follow.
Within that, though, the actual criteria for earthquakes
comes in, what the standard is called is green.
The Seattle look there's called the Sea color book as a seven dash 16
that tells us how to design for earthquakes in there.
And what it actually does.
It talks about how strong the building needs to be.
Remember that 3% is a minimum.
That still, again, is in this document.
And how stiff it is, I mean, how much it can
how much earthquake can cause a building to sway.
We want to make sure it doesn't sway too much.
It also tells about how to connect the pieces together,
how to connect the vertical columns and horizontal beams so that they work
together and perform a robust system that can absorb the earthquake energy.
And finally, it provides requirements
for non structural components.
You saw in the videos that the stuff above you and every room I go into,
I never ever sit underneath a chandelier.
Why you saw the videos, but we do have requirements for that as well.
So to try to minimize it doesn't do it perfectly.
That damage that causes from nonstructural components
falling all around us.
Within that, though, I want to describe what are what are we are
objective performance.
What are we looking at when these different earthquakes occur.
So I describe to you our performance objectives and performance.
I'll start with a cartoon series
where it is built here.
It's operational and it's
this is what we expect, 99.99% of the time a building performs like this,
but the earth starts to shake, Things can go wrong, things can happen.
The next performance of what
we think about as engineers, it's called immediate occupancy.
It's it's a it's a performance level such that we're still sitting here.
There may be some ceiling tiles falling down.
We may have lost the lights for a little bit, but we can get back in
and use that facility quite handily.
What we target, though, is something we call life safety.
After a major event, we want people not to die
and not to be seriously injured if we can help it.
But in doing so, damage occurs to the structure,
not just the natural components you saw in those videos,
but to the structural elements that are designed to support the building
and absorb the energy.
And finally, if the very rare event comes,
the very, very rare event, we don't want the building to collapse.
We want we want a very low likely to collapse.
That's when the major deaths occur from the shaking hazard
when that last little graphic occurs.
Let's look at this with real pictures from real earthquakes.
What does this look like?
This is from the 1999 chichi earthquake in Taiwan.
These buildings are being occupied immediately after the event,
being used and occupied and people living there right next to both
these buildings are buildings that absolutely collapsed.
Okay.
So you can see in one slide immediate occupancy versus collapse
in the same slide.
That's that's that's a graphical representation of a picture of real
buildings.
Here are visual of buildings at a life safe level.
The structural elements that are designed, again, to support the building
and absorb that energy, that those elements do get damaged.
This building is safe.
Nobody dies in this building
or even gets injured, but the repair costs could be large.
It may not be economical to repair it all.
You go a couple of blocks away,
you see buildings like this that are teetering on the brink.
They didn't collapse. This is collapse prevention.
But you can see they needed to brace this building here in the corner
to make sure that it didn't fall over in an aftershock.
So that's the cartoon version.
Real pictures, hopefully
providing an image of what we do, what the performance levels look like,
what are what are we suggesting in the code that we were delivering?
We're attempting to deliver
and we're present to what we call a seismic performance matrix.
It sounds like an engineering term, right?
It's just a table of information and definitions.
And on the one side, we
talk about the ground motion levels, the amount of shaking matters.
We talk about the frequent shaking at the top.
That's the earthquake that occurs about every 25 to 50 years.
That's the highest quality type of earthquake for us here.
That's that one.
The next one is the design earthquake.
That's the earthquake we designed for in the building code itself.
That's the one we we target as our performance and the last one.
And that occurs
about every 300 to 600 years, depending on what part of the country you're in.
For us, it's about 600 years.
And then last one is a maximum considered earthquake.
We define it as that because that's the maximum one
we want to consider, because Mother Nature knows no bounds.
We want to kind of do something that seems reasonable for us.
That's about a 2000 year return period event, not in our lifetimes
what can perform is that we take those same
performance levels I just showed you operational,
immediate occupancy, life, safety and contravention, and we marry the
two together and describe with a line what we are trying to achieve.
So for a standard building, a standard brand new building,
and you could think about all those brand new buildings
in downtown Seattle have been built in the last ten years
that given that design earthquake,
that dot in the middle says we want to be life safe.
That event that occurs about every 600 years is life safe,
given that very rare event, that 22,000 year event here in Seattle,
we don't want the building to collapse or it has a very low like to have collapse.
And then I also have in the slide called what we call a basic retrofit objective.
We do the same things when we when we fix up existing buildings.
I'm not sure you're aware that you're in a building that's been retrofitted.
Our company had the pleasure of retrofitting this building
to that performance level, so we should be okay.
I'm not guaranteeing a darn thing.
As I mentioned before, though, we look at essential facilities.
Are these other buildings differently because we as society
need them to a higher level like hospitals, EOC’s, police stations,
those essential those we we design them to a higher level of performance.
Given that design earthquake, we shoot for immediate occupancy and for that
very rare event, we shoot for life safety for their performance.
So I just want to emphasize we don't earthquake proof anything.
Damage will occur.
We try to control the damage by the way we design our buildings.
So I want to go through and kind of uncover, if you look at a building,
what is inside the building that guys like John Hooper cares
about that helps protect the lives of people?
I'm going to show you the systems that are typically used that
support a building during earthquakes.
I'm going to go through a handful of them.
This is what we call a steel moment frame.
This is the one that performed badly in 1994.
Luckily, this was built after 1994.
This is a building in Seattle that our firm designed.
But those horizontal beams, those vertical columns,
those combinations are what is designed to absorb
the energy from the earthquake and keep the building from coming down.
You can take a steel building and put these braces in
and these little cross braces see them everywhere along here.
Again, these are all Seattle buildings.
And that those braces, those x braces, absorb that energy.
And that's another one of our systems that we use quite a bit.
Just so you know, there's over 80 systems we can choose from.
I'm not sure I'm can show you all 80.
And we'll be here all night.
I'm going to show you my top five.
This is a concrete moment frame.
This happens to be in.
It's similar to steel, but it's made out of concrete
and a whole bunch of really, really important reinforcing steel
within the concrete to do the work and protect the building from swaying back
and forth too much.
Some may recognize this building in Bellevue.
This is exterior of concrete shows.
Those are all thick walls with a lot of reinforcing steel,
and that is designed to do the work to protect the building.
Over last 15 years, nearly every tall building you see in downtown
Seattle or Bellevue is made out of this or made out of this, supported by this.
If you unpeel the exterior of the building concrete core walls,
they are very robust.
It's those the combination of the beams...
the pointer doesn't work anymore.
Combination of these beams and these walls together are what protects the building.
And there's a lot of reinforcing steel.
If you ever had a chance to walk by one of those sites, you saw something
you probably couldn't even see through the reinforcing seal.
It was so dense.
And finally, where most of us live in houses,
hopefully what's there is just a plywood.
This house should be my beach cabin and I may try a lot of plywood.
I want this one to make it as robust, but that's the type of material that's used.
And probably 90% of the buildings that get built anywhere in the United States
is built like this.
And the plywood you see there, all the walls are what is there to resist
that.
And I also want to reemphasize nonstructural performance.
It accounts for over 70% of the earthquake losses, I mean, close to 80%.
But critical systems are designed to a higher standards like the sprinkler
systems and egress stairs so that the fire can't burn it down.
We learned that in 1906 and also that that you can get out of the building safely.
We designed that for a higher standard.
I want to show you, though, the technology has changed dramatically for us.
Here is a tall building, the tallest building in San Francisco.
This approach we use to simulate earthquakes.
We take the earthquakes from Erin
and then we simulate our system
and then we see and we this is overexaggerated people.
This is moving a lot more than it should.
We look and make sure that
the building is robust to take this level of shaking.
And this happens to be magnitude eight on this Andreas Fault
in Seattle, we use a magnitude nine on the Cascadia to make sure that
the components that are supposed to resist that earthquake energy can do so.
So that's the technology that has come a long ways for us.
Again, exaggerations people exaggerations,
exaggerations.
I'd like to close with this the future efforts.
I think we're a long ways of doing the life safety pretty well.
I hope we are.
I hope Mother Nature doesn't surprise us too much.
Next time, what are we doing to help improve resiliency in earthquake
and design?
We want to look beyond life safety and collapse prevention. That's
but not sufficient.
What we're trying to do is estimate, given our current designs
for life safety and collapse prevention, how long it takes
the building to get repaired and back to use what we call
functional recovery after, let's say, a 500 year event.
Once we understand how long that is and we don't like the answer,
we can start to provide new ideas, design and construction strategies
to reduce that so that we can get back into our buildings
and instead of two months, five days or something like that.
So we're looking at that in a whole new paradigm shift
because I think we as society want and should be doing more.
With that.
I'll close
Yeah, Thank you very much.
That was great. So our final speaker tonight
is Barb Graff, and
I first met Barb back in, I think, 2000 when she worked
as the Emergency emergency management director for the city of Bellevue.
She is now the the director of this
Seattle Office of Emergency Management.
And she's going to talk to us tonight about emergency
preparedness.
Thanks, Brian. Thank you.
So use this one.
This is great news.
I'm enjoying being here tonight
because ordinarily I am the most depressing speaker of the night.
Erin had me 5 minutes in, and if you stayed awake for her,
everything I have to say is good news compared to everything
they had to share with you.
So this is a fabulous.
So just why I want you to be aware of the fact that emergency managers
all around the world, and very much so here in Seattle, are utterly
best friends with our scientists, with Joan and Brian and Art
and Erin and Harold and Steve and Brian and everyone else.
We believe what they say.
And I'd like to share a little bit with you
about what it is that we've been doing with their information as a result.
First, we're trying to humanize and personalize that risk information
that they spent a lot of time and a lot of really good study on.
We created a hazard map that we put on our website
so you can click on your home address or your kids school or your doctor's office
or your mother's house to find out is it in a floodplain?
Is it built on a soil that could potentially liquefy,
or is it a building that, as far as we know, is an unreinforced masonry building?
The more you know and personalize the risk,
the more you're actually likely to do something about that.
I'm going to talk real briefly about the kinds of things
that the city of Seattle, as a representative city, has done
with this risk information.
One, we plan our hearts out in the city of Seattle alone.
Go to our web page, Seattle dot gov slash emergency.
You'll find a comprehensive emergency management plan and emergency
operations plan, a recovery framework, All hazards mitigation plan.
You'll find continuity plans, continuity, government plans, continuity operations
plans, incident specific plans, including an earthquake response plan.
You'll find all kinds of things that have pre-staged what our intentions
are in any kind of an incident.
Additionally, we have partnered with an interesting startup company
called One Concern to model at a much more granular a block level.
What are the kinds of damage we might expect to see?
How many people of different ethnicities and languages and income levels
live in each one of those blocks that we need to plan better for?
And we also had just recently, relatively recently finished up
a seismic study of the entire water supply system, the city of Seattle.
Next, we train.
So there's 250 people
from our 30 city departments who get trained on a regular basis
in what their role is in an activated emergency operations center
in order to provide response in relief to our community in any kind of a hazard.
But especially in earthquake, we spend 85% of our time
focused on earthquakes because you focus on that and you're
kind of covering almost everything else on your bad day list.
We participate in exercises.
We don't wait for the earthquake like you heard earlier.
It's it's like John said, it's tough to wait to see if your best assumptions
were good assumptions waiting for the earthquake to happen.
So we actually design exercises to stress the plans
that we built and trained on to find out how can we improve them.
We also send people around the country and around the world
to help in different disaster situations because they come back
better inspired with good ideas to improve our plans.
There's a number of projects that we have spent
a lot of funding on here in the Northwest.
And so I want you to to be aware of that.
Some of those are we have finally torn down the the viaduct
instead of waiting for the earthquake and two sneezes to take it down for us.
Yes, we got it done. Thank you very much.
The tunnel has opened up.
Yay! We're making our way along.
We have completely redone the Elliott Bay seawall.
We'd like separation between water and land.
We rebuilt from scratch in a new location.
Seattle City Hall.
These are some of the essential buildings
that John was referring to because of the services
they need to provide a new city hall, the justice center, the fire alarm, or the
fire department and water department training center and the fire alarm center
so we can still take 911 calls and dispatch appropriately.
Additionally, we we used to have located in the Seattle Municipal Tower,
our main data center with all of our critical operations on floor 22.
And when we were finally embarrassed enough to face that, we've now relocated
and made two redundant centers outside of any kind of high rise or area danger.
Additionally, and I give credit to this to Mayor Nichols, who when he visited
Kobe, Japan in 1995 after their earthquake, he came back
with fire in his belly and recommended to the citizens of Seattle,
let's do more for public safety, especially in the earthquake arena.
We've now seismically retrofit all of our fire stations
so that the units, the firefighters can actually get out and do some good.
We harden the water hydrants so they can draw water more reliably.
We built the city's emergency operations center that we now occupy.
We cached stores of emergency congregate care supply materials
so that we can take care of
at least 4000 people right off the bat in different areas of the town
and many other things in order to get ourselves much better prepared.
Additionally, our community centers, our parks and recreation
are those facilities we would use for mass care and congregate sheltering.
And we've taken the time, trouble and expense
to make sure that they have been seismically mitigated.
So we can use them for that purpose.
For the top tier, the highest capacity community centers.
We've also installed permanent generators and we have a fleet of generators
that can be rolled around
to other critical facilities depending on what their function is.
One of the top dangers right after the shaking of an earthquake
is the exposure of fire
and given the fact
that your fire suppression systems could easily be damaged, etc.,
we went hit and installed automatic gas, shut off valves at 35 of the city's
most critical facilities so that a certain calibrated level
and this isn't just a heavy truck passing by,
but the natural gas will automatically be shut off
so that we're protecting from a secondary danger that hasn't yet even happened.
We touch John touched a little one on one unreinforced masonry.
I could talk about this one for hours
and you'll be glad to know that I'm not going to.
But the good news is for for at least the last seven years,
the city has been trying to figure out how to be the first city outside
the state of California to mandate seismic retrofit
Of the 1145 buildings that make up our unreinforced masonry inventory.
And we're going to get there this afternoon.
I was just in meeting in the mayor's office about
how do we weave together the financial incentives that help
not displace the low income, the minority populations and and the historically
significant buildings that we don't want to lose in our next earthquake.
This is not this is not an easy thing to do.
This is about a $1.2 billion proposition.
And unlike the other billions of dollars of investments I showed you that the city
made with tax dollars, that's $1.2 billion on private property owners.
So we're trying to be sensitive about the way we did this.
We tried it in the early 1970s and then following the 1965 earthquake.
Earthquakes are great, great motivation, but it doesn't last long.
And so we passed an ordinance and within four years had repealed it
because we had not been thoughtful enough about
how to make sure we could put a retrofit ordinance in that would address this.
But 33,000 people at any given time, any day
are living, sleeping, working or dropping their kids off at school.
That is an unreinforced masonry building.
So we've been we've been in a in a very close neck tie with Portland
for a number of years, trying to shame each other
into seeing who's going to be first at this.
I guarantee you Seattle is going to be first to get around to this one
town hall.
John stole the thunder.
It's seismic retrofit, so give yourselves a hand.
You're in a safe.
No hurry to get out Bars open as soon as I'm finished here.
But in addition, in addition to that, in addition to town hall itself,
we have since 1997 teaching classes to people who live in the community
whose single family wood structures are not adequately secured
to their foundation because they were built to a previous older building code.
And so we started a program
called Project Impact way back in the mid-to-late nineties,
where we teach people, Here's how you can do the work for yourself
if you're willing to do that.
We have two community groups who actually loan you the tools to do it.
If you don't want to buy the tools, we teach contractors and since 1997,
we keep
we continued to teach
those classes into 2019 and they continue to be standing room only.
So I'm so impressed about the investment people living here in the community
themselves are making in disaster preparedness.
But in reality,
with all that investment that we've made, it's still going to be a horrible day.
And so the most important thing, remember, is this is where I do get
is depressing as all my remaining colleagues.
What you need to remember is the just in time
delivery, including just in time delivery of your dinner.
Things just aren't going to be normal for us for quite some time.
We have hundreds of bridges in our city alone,
let alone the thousands that connect us to the rest of the world.
With so many different important enterprises,
including hospitals that count on just in time delivery of services,
This is going to be urban camping for a certain amount of time.
And so we're trying to encourage people to personalize this risk
and say you need to do something about this at the household level,
the way your city has been doing it with public buildings in it
as well. Toward that we teach more
than 10,000 people annually in person,
not to mention all the people we try to reach with TV programing,
with our websites, with Val, we have our volunteers here tonight.
Say hi to Cindy and Ann and others on your way out there doing absolutely
fabulous job.
We hire people who are culturally competent and fluent
in a language other than English to teach the classes on our behalf
in order to get to especially immigrant and refugee communities
who don’t necessarily trust their government.
You don't have to be an immigrant or refugee to not trust your governement system.
You need to change that to to as we have been,
we have been encouraging people to sign up for a program
that we have called Alert Seattle.
You won't need this to find out about the earthquake.
As Harold mentioned, earthquake early warning is on its way.
But when we can send you information about specific areas of damage,
a utility disruption, a traffic disruption, a law enforcement
activity going on in the area, sign up at alert.seattle. gov
So we can push that information to you.
And then finally and we've got these brochures over on the table.
It is all about preparedness.
And so a lot of people think about gathering their supplies, right?
A lot of people think about put it in a good plan together.
Who's going to contact the kids and and out of area phone contact.
Right.
But I'll tell you, I'm absolutely inspired by a disaster sociologist by the name
of Daniel Aldrich, who has studied disasters for decades and has proven
what gets us all through a disaster is a sense of connection.
And so what you need to do, in addition to the fabulous supply kit you've got
and the wonderful plans that you've laid out, you actually do need
to get to know your neighbors and you do need to talk about this at work,
and you do need to ask your kids school if they've done a drill recently.
More people get themselves through horrible disasters,
especially no notice ones by counting on one another.
It works.
There's some fabulous literature out there that you can read about, and all of
those books are listed on our website, but it's what we need to do.
Well, the last thing I'll save so that we can get on to questions.
And again, this is amplified over with our community volunteers
on the side of the room
through research in disasters for a long time we realize,
especially in earthquake country, people
naturally are very altruistic.
Within the early hours and days of an event like an earthquake.
And so we thought, what can we do to help make that?
What can we do to help make that connection happen?
And so we worked with a lot of community members throughout the entire city to say
where close to where you live or go to work or wherever you spend your time.
You tell us where a natural meeting place is
so that if you needed to help one another out, you could,
even if you want to guess how many firefighters we have on duty tonight, 200.
Very good. About 210.
And all of them are absolutely spectacular.
But they team up and so there's only about 35 apparatus that they all ride on.
That's the same number we're going to have on the day of the earthquake.
What you can count on, though, is another 730,000 people who live here
who have taken CPR training, who have taken classes like this,
who have organized themselves into groups willing to help one another out.
This works
community hubs are are simply locations where we encourage people who need help
and people who can help will get themselves together.
I'm going to go ahead and abbreviate myself
so we can get to questions because I bet you guys
have a lot of things you want to ask us about.
So fellow presenters, come on back up again.
(Audience) I was curious about the intervention of,
you know, I've been a little bit obsessed with gas.
The gas shut off, and particularly the opportunity to have that in homes
feels like I'm curious what other kinds of interventions like that would you are
would if you could sort of have your wish granted that you would
be able to get people to do
would you want to.
Learn about the rest utilities?
Is this what we learn about the rest of your utilities?
So automatic gas shutoff valves, great idea.
If you're doing this in your home, be aware of the fact
a professional needs to be able to restore the gas after the shaking itself.
But learn where you could turn off your water
so it doesn't become contaminated with other damages for done in the system.
You've got a lot of water in your water tank.
Some of you have a lot of water in your water tank,
and you get to know your neighbors in case you don't.
But think think about what what else you can do to kind of
shield off, you know, your home and then share it Stone soup.
And actually, a lot of people do this naturally during power outages.
I do.
I always take the dog for a walk out in the neighborhood
and, you know, start talking with people about what it was they experienced
last mile is important point that you brought up.
Also Seattle is participating in an eight county wide planning effort
right now, regional catastrophic planning in order to identify with a lot
of good information from transportation managers, geologists and other.
Where are the most likely places Once we can get supplies into the areas
that we could put points of distribution so that I can,
within within a relative within the course of the grant
within two years, be able to give you with a certain level of confidence.
Exactly where am I going to drop off food, water, shelter materials, etc..
Thank you, sir.
(Audience) My question for Dr.
Wirth, you showed simulations of the M9
earthquake and happened in 10 seconds.
Can you give us some idea of what the timescale
was for the arrival of the shaking and the curation?
Yeah.
So the the actual rupture does take some time is it's more like
on the order of a minute or two I would say, and then the duration of,
or a few minutes actually, and then the duration of shaking.
So we often like to compare this
to the Nisqually.
So I think the Nisqually was about 20 seconds or so of strong shaking.
Someone on the stage can correct me if I'm wrong, and four is for
the Seattle area and then for a magnitude nine earthquake,
we would expect that it would be more like 100 seconds of strong shaking.
So about four or times longer for a magnitude
nine earthquake for the duration of shaking in the Seattle region.
Yeah.
So it's maybe a little bit longer than you thought based on the simulation.
(Audience) Hi there.
Thank you all for coming tonight. Thank you.
My question for John Hooper,
you spend most of your time for residential and commercial structures.
Is there any history or performance data
on liquid storage
structures like tanks, water, petroleum, that sort of thing?
Yeah, yeah.
There's part of that HFC seven standard.
There's a whole chapter just with what we call non building
structures, including water tanks, petroleum tanks, all of those tanks.
And they are, if they're an earthquake country, are designed
for seismic equivalent to what we do for buildings
and sometimes higher because of the contents. Yeah.
(Audience) How they do are they call history or go.
Well we had a real life example in Chile 2010 and the newly designed water
tanks and petroleum tanks all did actually very well
with a magnitude 8.8 event.
So they designed very similar lead to what we do here in United States.
And that was a great test of Mother Nature, again, that
what we do as engineers seemed to work well for big storage tanks.
(Audience) Can you speak to the small mom and pop residential rainwater tanks that I.
That I that that is is exempt from our standards.
So I really can't talk about that one.
So I hope they work fine.
(Audience) Hi, this question is also for John Hooper.
This is it's kind of I guess more leaning towards a structural end
the simulated model that you showed of the tower,
the tall office tower in San Francisco.
To what extent is glass
curtain wall
covered in sort of the structural design of buildings?
That's a great question.
Well, will we be raining glass down on the street
looking at our standard that we use to design buildings
to given the design earthquake, we designed the glass not to fall off
which so that's a pretty big event.
So we have a chapter just for that which is good.
And even given the maximum to consider earthquake,
the one that occurs about every 2000 years,
and all the new buildings we've been designing around town,
the engineering community, even the even the cladding itself is going to stay on.
It's designed to stay on.
So we've really upped our game, if you will, in the last oh, probably
15 to 20 years, thinking about the hazard
to the public around the buildings to try to mitigate that situation.
So I guess for you, for downtown Seattle, where there's all of these tall
glass skyscrapers that are being built,
the assumption is that the majority of them.
The majority of the new ones.
Yeah, the new ones, Yes. Yeah. I can't talk about 40 years ago.
That's a different animal. Yeah. All right.
So we're going to alternate, so please.
(Audience) Three questions, but all fairly quick ones.
Most of us over here in Seattle had thought that we were protected
from the effects of the tsunami by having all of that land between us
and the ocean.
Looking at the simulation, it looked like it right?
Right into Puget Sound, right into Lake Washington,
wiped out everything in a houseboat on Lake Union and just wanted to find out,
is that a correct perception
that even Lake Washington's going to get hit by the tsunami?
So let me preface this first.
So I mentioned that there's wide range of possible ground shaking scenarios
when there's an M9 earthquake.
There's also a wide range of tsunami scenarios.
But we do expect that, of course the largest the most damaging tsunami
is going to be along the coast.
We will have a tsunami that
travels down the strait of Juan de Fuca and into the Puget Sound region.
But that will take some time, maybe an hour and a half to 2 hours
after the earthquake.
So there should be plenty of warning for Puget Sound
area residents that are right on the water to get off the water.
And we don't expect the tsunami
to be nearly as high by the time it gets that far inland.
So I've seen some simulations of
a magnitude nine earthquake that maybe a meter or so tsunami
in the Puget Sound region.
But again, it takes about an hour and a half to 2 hours to get that far inland.
I don't know if anyone else wants to comment on that.
I was just.
I was just going to add one comment.
We just had a student who finished up her PhD looking at that,
and she found a couple of spots in Puget Sound where there is
geological evidence supporting a tsunami running ashore that appears
to be correlated with some of the past subduction zone earthquakes.
And in those particular areas, the model
predicts up to a couple of meters of run up.
So in isolated areas, it could be quite a bit more than a meter.
Yeah. Okay.
(Audience) I was wrong. That was going to be my quickest question.
So maybe I better just do one other
because I don't mean to steal everybody else's thunder.
A lot of the preparation seems to be dependent.
The reaction.
It seems to be dependent on cellular telephony.
How confident are we that are cellular networks are going to be there
functioning and having access to power after things happened.
- Not.
Damaged?
So, for instance, we have we've done a citywide duty to report
policy discussion and the members of my staff note,
you shouldn't expect a call, you shouldn't expect a page, you shouldn't expect
anything over the radio if you felt it, that was your call to come in to work.
(Audience) So this is not directly related to earthquakes,
but I'm curious about all of our volcanoes along the Cascades.
Will they be affected and become activated by any of these larger earthquakes?
It's yeah, it's an obvious potential question to say, well,
if there's so much shaking, could it not shake something loose in a volcano?
And there are examples from the past from from
from the last century of history, of volcanic eruptions seemed timed
sort of suspiciously closely with very large earthquakes,
including the the biggest earthquake we know about in 1860 Chile.
But when people really try to look at those stories systematically
and look for statistics of it, it turns out that
if there's any correlation, it's very, very weak.
I think the most you could say is that there's the potential
you could sort of make the hypothesis that a volcano that is balanced
right on the edge of erupting anyway could be triggered by the by the ground
motion, by the strong shaking that comes through from the earthquake.
Other than that, we don't see evidence on a global scale
that that that's a significantly frequent or likely likely event.
Good news for us, at least at first.
Yes, exactly.
(Audience) My question is directed at Barbara Graff, and I'm not certain
what your proper title is, El Jeffe or Madam OEM or
- Barb.
Barb.
Thank you.
- There was a mention of a 2016
Cascadia Rising report.
I may be the only person that have read it,
and it was refreshingly honest and horrifying at the same time.
And it mentioned the pooling of resources
into a disaster area and said it wouldn't work.
You had to shift to a push system,
whereas the local area is so on its lips
that the government, the national level, has to come in
without us asking them.
Can you talk a little bit about that?
Very happy to Cascadia Rising one
was the June 2016
functional exercise that involved four states, British Columbia,
all four levels of government, public
or private sector, 20,000 people participating all at the same time.
And it was meant to simulate
what does happen in a in a catastrophic earthquake like Cascadia,
where all of western Washington is absolutely decimated.
But we're along the I-5 corridor.
You've got the majority of Washington state population
shouldn't be expecting a whole lot of help or resources because of what's happened
out in the coast, eastern Washington, eastern Oregon, little bit better off.
We did a lot of really, really in-depth planning with the National Guard
to say what size planes need to need to make it to Fairchild, what size
aircraft, then need to make it to Moses Lake, what size aircraft.
Then make it in.
We planned with a Navy, with a Coast Guard, with all kinds of different people.
And the assumption has changed over the years.
It used to be, you know, we have an earthquake.
My mayor calls the governor and says this was horrible.
Can you help?
The governor thinks about it for a while.
Contacts the president.
That doesn't happen anymore. Is it?
For many different reasons.
You'll you'll see some of the improvements that we made.
And we need to be honest and candid that we don't always get it
right in these exercises.
The whole purpose of the exercise
is to break the plan so the plan becomes stronger and better with good assumptions.
So in Cascadia Rising II schedule for 2222,
we'll be taking that to the very next level.
(Audience) Hi, in a major earthquake.
Can you speak to the frequency and magnitude of of aftershocks
so that assuming we get the Shakealert system working?
Well for the first shock?
Kind of a segue way off.
The other question, too, is
in a major earthquake, can we not expect the system to work very well for the.
An aftershock?
Yeah, that's a great question.
And aftershocks
are potentially a really key application of something like Shakealert,
because you have people in already damaged buildings, ones where you're maybe.
Right, balanced on that edge of of life safety and you have emergency responders
that have to decide whether to be in those places.
We know that for a very large earthquake, typically
there is a relatively predictable kind of sequence of aftershocks.
And, you know, kind of we expect an aftershock of a magnitude,
you know, a one to several of a magnitude, maybe one magnitude scale down
from the main earthquake,
but with the significant potential of an even larger earthquake as sort of
an aftershock, then we kind of redefine as the main shock and and a foreshock.
But and then and then, you know, drop down to magnitude
in orders of magnitude, you you expect
to go up by a factor of ten of those, another order of magnitude even more.
So you expect hundreds of aftershocks.
And Anchorage saw this last year
and the Shakealert
system has the potential to be incredibly helpful for those aftershocks.
But it also has challenges.
One is when they were coming very, very frequently,
the system is going to be challenged to distinguish individual events.
So in those first minutes to hours after the earthquake, when the
you know, it's sort
of an exponential decay of aftershocks and when many, many events are happening,
that's going to be a challenge system.
And that's part of the technical work that still goes on and refining
and improving it, making sure it can really detect those events.
We hope, though, that it will become a critical component of that.
And one of the products that the U.S. Geological Survey produces now
for every significant earthquake is in,
it is an aftershock probability forecast basically going forward,
and it even gets updated every day or maybe more often than every day.
So that so that people in
California saw this with the recent eastern California Ridgecrest
sequence of earthquakes, where they're getting regular information
about the likelihood of an aftershock in the next 24 hours.
And you know that that set of earthquakes started with a 6.4.
Right.
And then the know it was stated that there was non-negligible
potential for an even larger earthquake, although typically
aftershocks are smaller.
And in fact, we had the 7.1, what, two days later, one day later, I forget.
Yeah.
So so that's actually a crucially important part of it
that I didn't didn't get a chance to talk about.
Perfect.
(Audience) So in the larger earthquakes you guys have studied around the world,
plus what we might expect here in the of the subduction Cascadia,
a 9.4 earthquake, what happens with utilities
in terms of natural gas and sewer and water conveyance
and electrical and transportation infrastructure, What have you seen?
What survives the most, What damages the most,
and what can we expect around here? Possibly.
You know.
We've un-nominated all of ourselves as being the next the experts.
So anybody in the audience want to take this one?
We're all well, what good with that?
What I can't say is,
for instance, I mentioned that our Seattle public
utility recently did do a seismic vulnerability analysis
of its entire system, where it draws its water from,
how it pipes it in, how it distributes, etc..
And I that Puget Sound Energy and other utilities
are doing the same sort of thing,
but you should expect disruptions to absolutely everything.
And there are standards, just like John talked about, for buildings.
There are standards for Lifeline components
such as water delivery, telecommunications,
fuel and other things like that.
I might want to add that
just to put
a note of one type of optimism on it is that we've seen a number of these
very large subduction earthquakes around the world,
the ones that around magnitude
nine or high eights are not very common, but there's been a bunch of them.
And Erin talked about Directivity, an awful lot of them push
their seismic energy sort of from below the shoreline out towards the sea.
And that's good news.
And in fact, you know, we look at Japan in 2011, Chile
in 2010, go back to the Alaska in 64.
You can look at a whole bunch
of earthquakes in many times these very largest earthquakes,
because most of the shaking originates from offshore are not as damaging
as we might anticipate for their scale from the earthquake directly.
That's not to say we're we're out of the woods at all.
But but, you know, damage in real earthquakes is very patchy.
You showed buildings that were collapsed next to other buildings.
I told you I experienced that Santa Cruz earthquake in 1989.
And I want to tell you
that large parts of the city were absolutely fine, whereas a building,
a house could be off its foundation and the one next door.
So fine that the China didn't fall off the shelves, you know,
and that's just the nature of earthquake damage of Chile.
I think after the earthquake had a lot of things
went wrong, but an awful lot went right.
And they really didn't have a very, very large loss of life
or even of of of property for the scale of the earthquake.
8.8
(Audience) So I just want to follow up quickly.
I participated in a study of the city of Mercer Island did maybe a decade ago.
And their concern was that
they were going to be out of water after a big earthquake
and their concern was very warranted because if you go under the East
Channel Bridge of I-90 and you look up all of the utilities
that feed Mercer Island are hooked to that bridge
and come from the east across that bridge span.
And I think at the time, the bridge and probably maybe still be
was designed withstand about 30% shaking.
And and so they were very concerned that they were going
to be literally cut off of everything.
And so they redesigned their water tanks
bolting down and reinforcing that to keep them from jumping around.
And they got a permit from the state and the federal government
to draw water out of Lake Washington for firefighting.
Yeah, So it is kind of the thing of get to know where you live
and where your utilities are coming from and make sure that,
yeah, you make
sure you know that they might be able to make it through the earthquake.
Yeah.
(Audience) I'm James Bila
I'm president, founder of Oregon Earthquake Awareness in Portland.
I've been working on Cascadia for 27 years.
About as long as Erin Worth has been alive.
Portland and Seattle have been in a century long test of wills
to see who can prove first that if you do nothing,
nothing happens.
When 1980, Steve Malone
was looking at the helacoiler
at UW in Mount St Helens erupted and
I put a quote from him in the article
I wrote 2014
and he said, Mount St.
The lesson of Mount St Helens is that in some cases
even the worst case scenario can be exceeded.
And what I would like to propose to Barb
is that
how we got to now isn't working that
what we really need as a community
You can always hire people to do what it is you want to do.
So I believe we should have
scenario
earthquakes to what we can expect in Seattle, both from Cascadia,
from local faults like the Seattle fault
Whidbey Island fault
that people can use
to build a community to withstand the maximum earthquake
on the Seattle Fault, which is about size of the recent
earthquake in Alaska.
But until we have that,
we don't know what we have.
And maybe
I'd like everyone in the panel to explain to the audience
what a 2500 year earthquake is, because if we don't
have to worry about that one, what about the 5000 year earthquake?
What about the 7500 year earthquake?
What about 100,000 year earthquake,
which were about due for.
I'll just start by saying I appreciate the comment.
And we we do study earthquakes around the world.
Christchurch, New Zealand, is one of our sister cities
and many of our staff members have been down there,
including our elected officials, and come home with the lessons
and understanding of the trauma that a community like that goes through.
Our electric utility, Seattle City Light, has tried to figure out
how do we do more microgrids throughout the city.
So we're not quite as we're able to to segment, but not break
and be a little bit more resilient in how we come back up again.
But you're absolutely right.
If we're if we're just thinking we're staying at home
and making this up in our head, we're never going to test ourselves
with the rigor that we need to to put really strong systems in place.
What is a 2500 year earthquake?
Brian's the man on that. Ah.
Yeah.
Just to comment on,
I won't get into details of how you sort of extrapolate
to to longer because it's a huge research topic
whether Cascadia produces, you know, just the same one
sort of beat by beat over and over again 300 to 600 years,
whether there are long pauses and then extra large earthquakes or not,
those are big questions, some of which we won't have answers
to until we've waited a few thousand years to see.
But, you know, you can kind of look at the maximum size of an earthquake
that just the geometry of the fault zone is capable of producing.
And it could be bigger than we than our current scenarios,
but maybe only up to as much bigger as, say, the 1960 Chile earthquake.
So we kind of know things about what at least the Globe has experienced
during this time.
And there are of the Black Swan event things that are very hard to plan
for the the you know, the biggest earthquake
the planet can have in a hundred thousand years
is bigger than what we've seen Clearly, but there is sort of a maximum scale.
We can't, you know, despite Hollywood movies, we're not going to get to a 10.5.
It's just not Fault's aren't that big.
Yeah, exactly.
I like to add one comment on the building side of things.
When I talked about 500 year events in 2000 year events,
when you look at that and this is my USGS colleagues
providing, us, the information in that return period timeframe,
we look at all the different events that could generate that kind of shaking.
So for us, that's about a 7.5.
Now the Seattle fault, I thought it was 7.2 until tonight.
It's a magnitude nine on Cascadia.
It's about a magnitude seven deep.
So in our design process here in the sound region, even though we have a return
period attached to it, it has scenario based shaking that we think about.
And the shaking I showed you for that building in San Francisco was a magnitude
eight shaking on this Andreas fault coming right at the building.
The Directivity thing, Erin, that you described.
So we do think about it in those terms of real scenarios
because if you keep this generic return period,
you've got to think about real events and what they will generate,
what shaking they will generate at the building site.
You're designing.
Yes, ma'am.
(Audience) Yes, hello.
My question is for Engineer Cooper.
What parameters you take on consideration
to add a damper system in your building design?
Okay.
What you're asking is more sophisticated technology
in helping to resist earthquake energy absorption.
That technology, called DAMPERS, has been around for quite some time.
The Japanese used it quite regularly.
We actually use it at Safeco Field.
The roof is supported that way and so is a Seahawks stadium roof.
T-Mobile.
Thank you. Whatever.
I'm old school. Okay, Barb.
So anyways, we don't use that technology as much as we perhaps could.
But as I mentioned, as we look towards improving our
performance measures and we look at this call, functional recovery
to help reduce damage,
I think that technology will become more important
because that's the way we'll need to go to help reduce the damage to buildings
and get us back into buildings faster.
Yes, sir.
(Audience) My question is
a little bit more specific and perhaps not answerable.
I mean, you've talked about scenarios and testing
under different building conditions.
I'm wondering about the floating bridges and the and the locks and what,
if any, studies have been done
about those structures and if so, what that might mean for us.
I the only one that I can
specifically address is the new 520 bridge.
And we were we were asked about that in terms of
of there's a big Seattle fault earthquake that produces a say in Lake Washington
where basically a big waterway where the wave is water sloshing back and forth.
What should they look for in terms of a rupture
to design for and how big a wave would that produce?
And they ended up settling.
And I really almost hesitate giving you a number because,
I'm sure surely going to be wrong, but I think they settled on
like a 12 to 15 foot wave and they built for that.
And that may have been changed in the final design,
but they did take that into consideration for the new bridge, the old bridges.
I don't think they even took any of that in the design, to be quite honest.
In the logs.
I don't. Think.
So. We have talked with the U.S.
Army Corps of Engineers and toured the locks
and what their emergency plans are.
It isn't that they're built to survive, but they do have a contingency plan.
They've got they have the ability to
to intentionally flood them with other materials
which will screw things up for a very long time.
But but limit the amount of damage.
And remember, the locks were built over 100 years ago, right, guys?
Earthquakes didn't exist for us.
100 years ago.
Yes, sir.
(Audience) Just following on that.
I was struck by our building.
Engineer explaining how we are getting so much new.
Information, and.
That codes keep getting revised.
So I'm wondering, structures like the Space Needle.
Or, you know, it's old timers to see first building or, you know, a lot of.
These skyscrapers that were built 20, 30.
Years ago.
What in a 9.0 earthquake
might happen to some of these high rises? Oh.
Boy. Is the camera off yet or what?
Clearly, we're progressing our technology in our in
our understanding of the earthquake hazard and the shaking that can occur.
We have been designing for earthquakes for this whole timeframe.
And when and I have done some studies of some tall buildings in Seattle
that are older vintage,
their
reliability to perform well is not quite as high as new building.
That's rest assured that's the case.
But it's interesting in some of the buildings that we looked at
because a wind design pressures we designed for wind to the winds blow here
yeah for tall buildings is a big deal and you get additional
strength of the building because of that.
What you don't have as good as I
mentioned, is the detailing or the connection of the pieces together.
So that's not quite as resilient.
So again, I'd like to just describe it as it will do.
Okay.
It's not as good as say, but
just because the reliability isn't the same, it can't be.
And I can't put a quantification to that because we haven't done enough
detail studies because each of those structures
that were mentioned are very, very unique, obviously,
and it would take a detailed analysis like I showed on my little video
to really understand how those structures might behave.
(Audience) I mean, the Space Needle is fairly simple.
I mean, what about that 1962 structure and a 9.0?
Do you think.
I. I don't know.
I really don't.
I wish. I wish I to make something up. Not to be.
Yeah.
So I want to take these last two questions
and then we're going to take a break and you can get a beer and there you go.
And I'm going. To beer around.
So if you feel like if you want to ask other questions, feel free.
Can I just make one more comment to follow up on that last question?
So this. Is basically.
No, no, but I was going to mention that in terms of new buildings,
I feel like the city of Seattle in the cities of Bellevue have been
very receptive to new research related earthquakes.
So in December 2018,
both of those cities actually updated their guidelines
for the design of tall buildings based on the M9 earthquake
simulations and based on amplification that we were seeing in those simulations.
So for new buildings, I think that actually
we've been very good about updating the design recommendations.
Just that, you know, that we were doing based on before that
to just not to the rigor that we found out from the M9 research.
Yeah.
And Jeff Berman,
who part of your M nine Project U dub has modeled the Space Needle, I think
and I'm not going to say
anything about the results because I'm no engineer and but,
but there's there's work that's certainly been done to look at exactly that.
QUESTION
(Audience) lots of tremendously
wonderful, interesting and thoughtful information.
So thank you for that.
But one comment that I heard that kind of stuck with me
was the importance of networks community as part of the resilience profile.
I think we hear a lot about having food, having water and less that.
And I'm wondering if there's actually any research
about how other places that have functional communities.
You know, is there something that we could do collectively?
Is there some
research to point out what works?
Yeah, just to unpack that some more.
There's there's an enormous library in Boulder, Colorado, at the Natural
Hazards Research Center, directed by chief executive officer Laurie Peaks.
And She's a good friend, she's a wonderful colleague.
And we learn from many of her research scientists.
Again, we're not trying to make up what we think we're going to experience.
These are people go around and study these things constantly
in something else.
You said
we are influenced by the international community as well.
So like I've been a member
of the International Association Emergency Manager for years and years,
and so we're constantly hearing what did and didn't work in Italy,
in Japan, in Hong Kong, in Chile and in Australia, etc..
So yeah, there's there's a big body of research, but I do
I do recommend the Natural Hazards Research Center.
Last question, sir.
(Audience) This one is for Professor Tobin.
Yeah, many, many, many, many precise GPS
stations scattered throughout.
And they are the good news.
You've found periodic seismic, silent earthquakes.
The bad news that found periodic.
So what is this data telling you?
What's it screaming at you?
What do you think you're going to get out of this?
Yeah.
So people have heard about the slow earthquakes
or what we call episodic tremor and slip. And,
you know, maybe people don't know that the same GPS that makes, you know,
your phone know where you are.
If you fix it to the ground and measure it continuously, we can actually tell
where that point on the ground is down to a sort of a millimeter or so
and see how it moves.
So we're actually measuring plate plate motions.
It's not just sort of geology anymore, But so what's happening is.
Right, the points on the ground in western Washington typically are actually moving
that few a year towards the east, and it's because the plates are stuck together.
But every once in a while, the portion under sort of the
the eastern side of the Olympics and just west of the sound here
and up across Vancouver Island down into Oregon,
decides for
a couple of weeks to turn around and move the other way for a little while.
And it slips a number of centimeters and then stops again.
And it's associated with this stuff that I hesitate to even call tremor,
because that makes everybody think of earthquakes.
It's actually sort of background seismic noise at a very low level.
No one ever feels.
But we measure, you know, thousands of these tremor
events during one of these periods of slow slip.
It turns out they're on a different part of the fault zone, deeper down the fault
closer towards the direction of where
I showed you, where this stuff comes from for the volcanoes.
Then the part that we're most worried about being stuck in locked
for the most part, we think.
And so what happens is, though, that that is moving the upper plate
just a little bit the wrong way or back towards and and a
hypothesis has been floated and is being thought about that
that is adding a little bit of stress to the sort of the back end,
you might say, kind of kicking the bottom end of the subduction fault in the place.
We don't want it to be kicked because that could trigger an earthquake.
There is no I mean, this clearly has been going
it happens about every 14 months in our region, kind of like clockwork.
And we got a little get lots of news media interest this August when it happened,
but then it kind of turned itself off earlier than usual.
And we've seen this anywhere else in the world.
Oh, yeah, absolutely.
So so this kind of these kinds of events are happening in Japan.
They're happening in a number of subduction zones around the world.
And even on the San Andreas Fault, another non subduction fault.
I guess the bottom line to cut to the chase
is that there's some evidence that sometimes big subduction
earthquakes are preceded by some sort of slow slip event.
But many, many, many slip events happen without an earthquake that follows them.
So they're sort of like foreshocks.
You never know.
Some of these a foreshock until a bigger thing happens after something you saw.
We don't have them as a predictive tool yet, but we're certainly very interested
in studying those events.
Thank you guys very much.
Like I said, we're going to be here. For a while.
Yeah.
Thank you.