Maryn Sanders
Join us for a coffee hour with Maryn on October 30th, 2025, 10am PST. Register here.
Tell us about yourself:
Hi there! My name is Maryn Sanders and I'm currently a fifth year PhD candidate at the University of Oregon, where I'm advised by Josh Roering. I'm from a small, rural town about an hour outside of Sacramento, CA, where I started my academic journey at community college, and then eventually transferred to UC Berkeley to get my bachelor's in Geophysics. While at Berkeley, I conducted an undergraduate honors thesis on rainfall-triggered shallow landslides and worked as a research assistant for the Eel River Critical Zone Observatory, which I continued following graduation. Over two years, I collected monthly soil moisture samples for isotope analysis to compare with local rainfall signatures, as well as deep bedrock moisture measurements to understand how oak trees use water stored deep in the subsurface.
What is your research about?
I work to understand the dynamics of the Columbia River Gorge (CRG) escarpment--a steep rocky landscape at the northern border of Oregon. The escarpment lines the Columbia River, is underlain by young (~1 Ma) extrusive volcanic lithologies (basalt, ash, hyaloclastite, etc.), and has recently experienced the Missoula Floods--large glacial lake outburst floods that ran out along the Columbia River ~15-20 ka. Furthermore, in 2017, the Eagle Creek Fire burned 50,000 acres of the CRG, and we mapped hundreds of post-fire debris flows using differential lidar from 2018 and 2021 and 2022. Thirty percent of the debris flow inventory was concentrated in 10 small (<1 square kilometer) and steep (basin averaged slope > 40 degrees) catchments, where some debris flow initiation zones were burned and some were not. My first chapter worked to quantify erosion rates over four timescales to quantify long-term (10^6 and 10^4 years) and short-term (10^1 and 10^0 years) erosion rates to test if the post-fire response was exceptional in these catchments. Erosion rates over 10^0-10^4 years were an order of magnitude faster than the background million-year (10^6) erosion rates, alluding to a minimal influence of fire on erosion. This shift to rapid erosion is perhaps coincident with transience induced by baselevel lowering from the Missoula Floods, or a decrease in basalt permeability that promotes fluvial dissection (typically taking on the order of millions of years post-eruption). Ongoing work includes quantifying conditions required to trigger debris flows in these steep catchments, mapping the morphology of fans along the escarpment, and quantifying relative rates of sediment accumulation.
What excites you about your research?
The Columbia River Gorge is a fascinating region, with complex history, compounding hazards, and loads of open-ended questions. I really have enjoyed getting to know a place so intimately, and I hope to take the same style of research with me into future projects! Additionally, I am working with two PhD students on a PhD-student-led side-project on slot canyon formation, and working with them has given me confidence as an independent researcher and stoked my excitement for what a future career in research could look like for me! I highly recommend it to other students if they get the chance.
What broader importance does your research have for society?
The implications of my research provide a reframing for our expectations of fire in transient landscapes, where prior to the fire the recurrence of debris flows is already so rapid. Furthermore, my first chapter provides estimated rates for the frequency of large debris flows based on long-term erosion rates and historical observations, and future work will help define the types of storms necessary for initiation of these events.
What inspired you to pursue a career in Earth Science?
My first class at Berkeley was Geomorphology, taught by Bill Dietrich, and it didn't take long to understand that (1) Bill was an awesome person to learn from, and (2) I was quickly developing a passion for research. The semester consisted of four field trips that culminated in four research reports, which were foundational for understanding what a life as a "scientist" could look like (plus many, many conversations with the TA's for the class).
What are you looking to do after you complete your PhD or postdoc?
Once I complete my PhD, I would pursue an opportunity that would allow me to continue research in geomorphology--whether that's in a postdoctoral role or a research-oriented industry position. I mainly want to keep working with awesome people on interesting questions!
Given unlimited funding and access to resources, what is your dream project that you would pursue?
The Columbia River Gorge is a steep and rocky escarpment that extends from the Columbia River up to a 1 km high low-relief plateau emplaced by volcanic eruptions ~1 Ma--everything in between is near-vertical and dangerous to access. The region also exists in a federally protected Wilderness Area, so it's illegal to install any instrumentation. In an imaginary world, with access to unlimited funding and resources, I would first convince folks that it's important to monitor these incredibly debris flow prone sites. Then, I would work to gain permits to install instrumentation to measure conditions that initiate debris flows and hire canyoneering teams to access debris flow initiation source zones. I would also (1) work with collaborators to develop equipment to measure stream discharge in small, steep streams that can withstand large mobile bedload grains, or even debris flows themselves, (2) purchase and install a SNOTEL-esque site at the escarpment edge to measure rainfall and snowmelt, as well as numerous other rain gauges within catchments to capture variability in rainfall totals, and (3) drill shallow and deep wells to monitor groundwater fluctuations along the rim. These small <1 km2 catchments have streams that run year-long, so the baseline discharge is likely sensitive to antecedent moisture conditions, but it's unclear over what timescales. With this information, development of a robust understanding of the region would help motivate conversations with the community about the local hazard and hopefully lead to the development of an early-warning system.
What else do you do? Any hobbies or interests outside of work?
Yes! I love weightlifting--the gym has been my happy place for the last 10-ish years. I am also a jack-of-many-mini-passions, which include but are not limited to: cooking/baking, coffee, crosswording, embroidering, learning all the racket sports, gravel biking around Oregon, snowboarding, thrifting, attempting to triathlon... etc!
Find out more about Maryn's work here: https://marynsanders.github.io
Email: marynsanders02@gmail.com