S2 E1: Alison Duvall and Tectonic Geomorphology

In this episode, Associate Professor of Earth and Space Sciences Alison Duvall shares about tectonic geomorphology, her work with the Cascadia CoPes Hub to increase knowledge about natural hazards and empower communities to build resilience in the face of environmental change, and her path to becoming a scientist.  

Duvall is a geologist who studies how mountains are built and how the landscape responds to these processes. More specifically, she looks at how plate tectonics, erosion, and climate all work together to shape the Earth’s surface across both space and time. In addition to mountains, she investigates what happens when two blocks of Earth’s crust slide past each other (called strike-slip faulting), changing hill slopes, river channels, and other features of the landscape. Because they are often continuous for long distances, strike-slip faults are especially prone to large earthquakes, but measuring their activity is hard. Duvall hopes to develop new ways of both recognizing and analyzing fault activity directly from surface processes.

https://environment.uw.edu/podcast

Transcript

00;00;07;26 - 00;00;21;00
Sarah Smith
From the University of Washington. College of the environment. This is FieldSound.

00;00;21;02 - 00;01;03;13
Sarah Smith
There's an intricate relationship between the Earth's surface and the unseen forces that mold it. Walking around every day, you might not think about the ancient movements, the monumental shifts that shape the landscape. But the secrets of our past, present and future lie just beneath our feet. U-dub Department of Earth and Space Sciences associate Professor Allison Duvall explores the riveting stories told by rivers, landslides and mountains in motion to better understand how our planet surface responds to geologic processes, peeling back layers of our planet's past, present, and future in her research.

00;01;03;14 - 00;01;33;00
Alison Duvall
My name is Alison Duvall. My pronouns are she, her, hers. I was trained as a geologist, so I have a B.S. degree, a master's degree, and a PhD in geology. And my expertise is at the intersection of landscapes and plate tectonics. So I'm really interested in how the Earth responds to plate tectonic activity and in particular the surface of the Earth.

00;01;33;02 - 00;01;58;02
Alison Duvall
So that means I care about things like how rivers incised or how landslides move across the surface, and how they do that in response to mountains rising and earthquakes shaking. So I will admit that I am the first and only person in my entire immediate and less immediate family who is a scientist, and especially an earth scientist.

00;01;58;04 - 00;02;32;18
Alison Duvall
so it didn't come necessarily from sort of a long line, but it came actually from an innate curiosity that I identify in myself, even as a really little kid, where I just couldn't stop being curious about the Earth. picked up every rock, turned over every stone in a river. it's it's not just that I was interested in kind of the rocks, the dirt, the mud and and the mountains and the landscapes, but also just animals, you know, basically just a nature kid, I would say.

00;02;32;20 - 00;03;04;16
Alison Duvall
But I had no idea that that was anything that you could, like, do anything with because I came from like a family of lawyers and business and banking and whatever. and so I just kind of kept it as my little side passion went on to college. And then as part of a requirement from the business degree I was pursuing, I had to take, an intro level science class, and I picked geology, and I was in a room with 500 other students, and I was enthralled.

00;03;04;19 - 00;03;29;04
Alison Duvall
And at the end of the semester, the professor asked if anyone wanted a tour of his lab and to meet his grad students and four of us out of 500. Wow. Went down. and it changed my life. I, like almost immediately switched my major and realized that, gosh, this is an actual thing, a thing that I can pursue.

00;03;29;07 - 00;03;51;15
Alison Duvall
because the curiosity was always there. and there I went. A winding path and a curiosity about the world led Duval to fall in love with Earth science, taking classes. You don't know what will unlock what path will unfold. I know so many times I meet people and I'm like, how did you get to be in this thing?

00;03;51;16 - 00;04;16;28
Alison Duvall
Because there's not always like, an obvious direct path to everything that that we end up doing. and so, yeah, take that, take that winding path. You never know. Duval describes herself as a tectonic geomorphologist, and her work has taken her to some of the most remote and unique parts of the world. I work in a lot of different parts of the world, including this part of the world.

00;04;17;00 - 00;04;44;17
Alison Duvall
and I kind of gravitate towards wherever the plate tectonic boundaries are active. and in particular, I tend to focus, a lot on places where the plates are in some way converging or kind of ramming together. That means that, I have spent a considerable amount of time studying the Tibetan Plateau in the Himalaya. and, I spent six long field seasons as a PhD student in northern China.

00;04;44;19 - 00;05;07;01
Alison Duvall
in order to try and understand that part of the world. I have been doing a lot of work in New Zealand for the past decade. New Zealand is just kind of like, tectonic geomorphology. Disneyland. If you if you're interested in those things, it's like it's happening everywhere right now, right before your eyes. And it's just a spectacular place.

00;05;07;04 - 00;05;31;04
Alison Duvall
a large amount of my work is in Cascadia, and in the Cascadia subduction zone. And so we're working locally here in the Puget Lowland and Seattle. But we're also working, out in the coastal environments of both Washington and Oregon. Yeah. And that's part of the I say, work with the Cascadia Cope's hub. Yes. I am one of the PiS on that, hub.

00;05;31;04 - 00;06;00;16
Alison Duvall
And it is, just an incredible group. I'm really proud of the work that we're doing. Cascadia Cope's hub is a team of researchers working to increase knowledge about natural hazards, together with communities in Washington, Oregon and Northern California to increase their resilience and ability to mitigate impacts from hazards like earthquakes, tsunamis, sea level rise, landslides, and erosion, and help them adapt to a future in the face of a changing climate.

00;06;00;22 - 00;06;32;28
Alison Duvall
I love that work because, of course I'm passionate about all the different projects that I'm a part of, but one of the things that I think is so important about that work is that it's a way for all of us who are doing, the physical science research to overlap with, collaborate with, and co-produce the, knowledge, across the fields of social science, planning, physical sciences, and out into the community of stakeholders.

00;06;32;28 - 00;06;54;25
Alison Duvall
And those are decision makers. Those are policymakers. Those are just the people who live out in the coastal environments that are having to be resilient and adapt to change. And so it's just an awesome way to work on the kinds of important theoretical work that we like to do here in the University of Washington, especially those of us who are sort of physical scientists.

00;06;54;27 - 00;07;22;22
Alison Duvall
But to make sure that what we're doing is making an impact and, is making its way out into communities who need this, we are really, functioning as a collaborative group in its true sense. So we put that concept of co-production where you don't just kind of toil away as a, in my case, a geologist, and then later on, like unfurl what you've done and be like, hey, does anyone want this or need this?

00;07;22;22 - 00;07;43;01
Alison Duvall
Or, you know, and instead you talk to them first and you sort of make a plan together, what do we need to what do we need to understand? How can we come up? How can we come up with these answers? And like I said, I think it's really needed and I'm really proud of it. 

00;07;43;03 - 00;08;21;05
Sarah Smith
Natural disaster preparedness for communities at risk can mean the difference between life and death. We're no strangers to natural disasters here in western Washington. We live in the shadow of volcanoes. This is earthquake country, and this year marks the ten year anniversary of the Oso landslide, a massive, devastating event in 2014 that killed 43 people and destroyed dozens of homes. I know the USGS, for example, got involved to actually, like, right from the jump, to try and help with both the rescue mission and sort of the aftermath, which, it is really, painful but important work.

00;08;21;08 - 00;08;45;06
Alison Duvall
there's also like kind of boots on the ground, people that are like, okay, we need to collect information that's going to disappear pretty quickly, but they're usually engineers or geotechnical folks, sometimes geologists. my colleague Dave Montgomery and in s was part of the gear team as well as Joe Wortman in civil engineering. And they went out really quickly and collected a bunch of perishable information.

00;08;45;09 - 00;09;07;09
Alison Duvall
I, collaborated with both Dave, and Joe and one of my former graduate students from Houston in order to try and get information about the other landslides that look a lot like the Oso landslide that had are clearly out in the landscape there, because a big debate struck up, which is could we have known how common is this?

00;09;07;09 - 00;09;27;01
Alison Duvall
What's the frequency of these giant, landslides in this valley that actually cross run out a long distance and cross the valley? and if you look at a wider map, you can start to see that, oh my God, you know, this entire section of the North Fork still, igualmente is littered with huge landslides, some of them even bigger than the Oso landslide.

00;09;27;01 - 00;09;47;27
Alison Duvall
That had to have happened sometime in the past. But when so me and my team and led by a grad, a PhD student at the time, Sean, said, okay, we need to figure out how old these other landslides are, because that's going to help us to understand the frequency of these hazards and ultimately the future risk. for those who are kind of making their way through or trying to live in this valley.

00;09;47;29 - 00;10;07;28
Alison Duvall
So we ended up working on that, and actually had to kind of hammer out and devise a new method for dating landslides, because it's actually pretty difficult to date many landslides with just kind of the old classic ways that we do this, which is things like carbon 14 dating, but it's that's a little bit like finding a needle in a haystack.

00;10;08;00 - 00;10;34;20
Alison Duvall
And it's quite expensive. And like I said, not always possible. So we kind of ended up making a hybrid approach where we had some dates on a few select landslides, and then we figured out how rough those landslides were using high resolution lidar imagery. And there is a correlation between roughness and age, because we know that a landslide is roughest right after it happens, and then it smooths through diffusive processes through time.

00;10;34;22 - 00;10;55;15
Alison Duvall
So if we could calibrate how fast that smoothing happens in that valley, then we can run around every other place where we don't have a landslide age, but can easily measure its roughness in this, you know, with computers and this elevation data, then we can figure out the ages of all, all hundreds of them. And that's what we did.

00;10;55;17 - 00;11;20;20
Alison Duvall
And we found that actually the frequency of landslides, of that kind of size is about one every 400 years or so. So it is not an uncommon occurrence, especially over geology timescales. We're taking that method that we figured out, and we're using it all these places. I have a current PhD student who just got a paper published last month where he applied that same method to Seattle.

00;11;20;26 - 00;11;40;17
Alison Duvall
Also, he's part of Cope's, and we actually can see in that signal the last big Seattle earthquake in the record of landslides, because it turns out that when we start to parse through the data set, we can see, we can work with those seismologists and say, tell us what the shaking would have looked like from your simulations.

00;11;40;17 - 00;12;01;28
Alison Duvall
We're going to take that, and we're going to compare it to a new maps that we have of dated landslides. We did this for Seattle, and we see a correlation where a bunch of landslides that are around as old as the last Seattle fault cropped up in exactly where you would have expected the strongest shaking to be. And now, yeah, we're applying that, in the coast of Washington.

00;12;01;28 - 00;12;25;06
Alison Duvall
So I have a postdoc named Larry Lai who's now making a bunch of landslide maps, and he's trying to use this method of coastal Washington, and then we've already done it, and continued to do this work in coastal Oregon as well. You know, one of the things that we're doing as part of Cascadia Cope's hub is, you know, we're better connecting the simulations of earthquakes with the simulations of tsunami.

00;12;25;09 - 00;12;48;18
Alison Duvall
You know, the seismologists and the tsunami scientists and the modelers are all working together. Then we say, okay, we can take these kinds of, simulations of tsunami, and we can ask what infrastructure is going to be impacted by this? Because one of the things that's really important, especially if you live out in the coast, is thinking about what are you going to do if there's a tsunami warning, do you find your way to some of these towers?

00;12;48;18 - 00;13;24;26
Alison Duvall
If you exist some more trying to be built, or do you actually try and go for it? Do you have enough time and do you have the capacity and, you know, to kind of get all the way out to higher ground a little farther in inland? But of course, part of that calculation that we haven't added before, but it's very important is how many of those roads, if you were going to try and make your way out, would be impacted by landslides because the same ground shaking that's going to affect structure is also going to initiate potentially thousands of landslides.

00;13;24;28 - 00;13;44;19
Alison Duvall
And so we continue to sort of not think about these things in isolation and do our best to kind of combine, you know, and when we work with the infrastructure folks, you know, there are people who have really, really cool cutting edge models that helped, sort of like model the full transportation system and sort of ask that question like, who can get where?

00;13;44;22 - 00;14;02;13
Alison Duvall
When should we build a tower, when should we try and go? And you know, and so we're trying to to consider all of these things together. And then, you know, I mean, tsunamis themselves actually, you know, people don't think about this that often, but it's true that like a large landslide going into a body of water could absolutely trigger Izanami.

00;14;02;16 - 00;14;22;22
Alison Duvall
and so I we have a bunch of cool sort of side threads where like, you know, because we're all kind of in the same room on this project. It means that you can sort of strike up these conversations so that my US landslide folks are talking to snow folks like, hey, if we have models of long run out landslides that are going to go into, say, Lake Washington, can that feed into a model of a tsunami that you guys like?

00;14;22;22 - 00;14;27;19
Alison Duvall
Can we let's talk.

00;14;27;21 - 00;14;53;20
Sarah Smith
Defaults work involves developing new ways of both recognizing and analyzing fault activity. Recently, her work brought her to an unexpected place the Atacama Desert in Chile 

00;14;53;22 - 00;15;26;09
Alison Duvall
with one of my current PhD students, Tamara ArcGIS, who is herself Chilean. and, it's been us super exciting to kind of get a new place in. And I hadn't been studying before. It's kind of incredible to think about, but we are focused on the northern part of Chile, which is actually dry. it's the Atacama Desert, in fact, the driest place on Earth, or one of the driest places on Earth. and so when I compare that to, say, Cascadia or even the, the work we do in New Zealand, you know, the climate is drastically different, but the plate tectonics setting is really similar in lots of ways, including, you know, some of the individual faults that we're working along.

00;15;26;12 - 00;15;50;20
Alison Duvall
And, so we are really excited about what we're learning by basically saying, let's go to this environment that is completely different. I mean, we're talking not a single piece of vegetation is covering this fault system. I have never seen anything like it. And I can't wait to get back there because, you know, geomorphology was just just so interesting.

00;15;50;21 - 00;16;14;18
Alison Duvall
It's like Mars. You just look like Mars. If you if. Yeah. If you what? It looks like Mars, it really does like you just you feel like you're walking around in, like a movie set or something. You can't believe it's real. That means that we can sort of just see the essence of what this, these fault processes do to this bare earth landscape where there aren't any trees and there aren't any critters.

00;16;14;18 - 00;16;44;01
Alison Duvall
And, you know, the soil isn't very thick at all. but it's also like, it's crazy because I am a geomorphologist and I, I tend to study sort of the more vigorous erosional processes. I'm in this landscape walking around like, well, it hasn't rained here in 300 years, so it's just this incredible opportunity to try and really understand how all of these processes together make the earth look, and how there might be feedbacks between the faulting process and the original processes and all of that.

00;16;44;01 - 00;17;06;12
Alison Duvall
And if you want to try and understand that stuff more, one way to do that is to go to the complete end member of it and say like, okay, yeah, this is super extreme and there may not be a lot of other places on Earth that like, are like this, but how does it work here? And then like how do how does that help us to understand how it works in other places where you're turning on other features like rainfall?

00;17;06;14 - 00;17;26;21
Alison Duvall
Yeah. So it's it's just really cool. It's been really awesome to do this work, especially, I guess I'll just say, like at a place like the University of Washington and in a place like Cascadia, because I am also a community member that experiences the things that I'm studying. And so it's been really fulfilling, I think, to do that work.

00;17;26;21 - 00;17;49;00
Alison Duvall
And also there's a lot of other there's a great community here at the U-dub and in the College of the Environment, where we're all kind of working together to to try and think about things like coastal resilience or disaster resilience. And so it's been just I just feel really lucky to do it in a, due projects like this in communities where I myself am a community member.

00;17;49;03 - 00;18;13;12
Sarah Smith
A big thank you to our guest, Allison Duvall. If you'd like to learn more about Alison Duvall's work, visit our website. Environment dot uw Edu. Thanks for listening.