Unlike the Pacific Northwest, the Atacama Desert in Chile experiences very little rain. But the two regions are both seismically active. Faults in the Atacama Desert are slowly sliding past each other in a way similar to the Seattle Fault in Puget Sound and the San Andreas Fault in California. The Atacama Desert鈥檚 lack of rain makes it easier to see how those gradual movements shape the landscape over time.
Alison Duvall, a 天美影视传媒 associate professor of Earth and space sciences, and doctoral student will travel to Chile this month to study landscapes developed along these types of faults. Duvall has previously studied historic landslides at the site of the rainfall-triggered Oso mudslide and how rainfall, earthquake and landslide risks combine in Oregon.
UW News asked the two geophysicists about their upcoming trip as part of a new series, 鈥�In the Field,鈥� highlighting UW field research.
Where are you going, and when?
Tamara Ar谩苍驳耻颈锄-搁补驳辞: We will visit the , in the hyper-arid, or dry, core of the Atacama Desert in Northern Chile. The Salar is a dry lakebed that contains economic resources, in the form of salt, that is extracted from the basin and then exported around the world. We鈥檒l be there Nov. 19-25.
We鈥檙e interested in this area because it鈥檚 extremely dry and has active faults slicing through it. Only a few places on Earth register such low rates of precipitation, offering a landscape that stores climate and tectonic variations from the past 50 million years. At our field site, there are places that haven鈥檛 seen a drop of rain in 500 years!
As a result, this is one of the best places on Earth to study how landscapes respond to earthquakes and plate tectonics under hyper-arid conditions. Dry conditions slow down erosion and help preserve landscape form and enable us to observe processes, like tectonic processes, that modify the surface from deeper down.
Have you visited this field site before?
TA: I visited this site last fall with , another doctoral student in the Department of Earth & Space Sciences.
Alison Duvall: This will be my first time to this site, to Chile and to South America.
What do you hope to learn there?
AD: We want to learn more about the dynamics of slow faults that move laterally 鈥� strike-slip faults, similar to the San Andreas Fault in California 鈥� and how these dynamics control the shape of the landscape. In wet places, it鈥檚 hard to isolate faults鈥� effects on the landscape since water is the main agent driving erosion. What we observe on the surface in other places is a combination of tectonics and surface processes. However, thanks to the aridity of this place, it is easier to be confident about what is changing the landscape.
We鈥檙e also interested in how this landscape has shifted with a changing climate. This place was wetter in the past, and there is evidence of climate change happening to make the region hyper-arid. So we are also studying how the landscape has adapted to that change.听
What鈥檚 something that you enjoy about this field work 鈥� especially something that might not occur to most people?
TA: There is a really special feeling when you鈥檙e in the driest place on Earth. It almost feels like you鈥檙e on a different planet. You don鈥檛 see any signs of life 鈥� no water, no animals, no plants 鈥� but it鈥檚 just amazing to feel that nothingness.
Changes in the landscape are so slow that when you visit the site, you know that each step you make, or any perturbation we make to collect our samples, can be one of the biggest modifications to the landscape in hundreds of years.
Anything you鈥檇 like to add?
AD: I鈥檓 super excited to get to this incredible field site and spend time with Tamara studying it. We have done field work together in New Zealand, and I have done decades鈥� worth of field work in many different geomorphic settings, but never in a hyper-arid landscape like this one. I can鈥檛 wait to see what we find!