Amy East

I study how landscapes change over time, focusing on response to hydroclimatic and anthropogenic disturbances. These studies inform resource management as well as fundamental understanding of earth-surface processes. I am also interested in how sediment moves from source to sink, and how the sedimentary record reflects changes in sediment supply and transport.

Biography

Research Geologist, 2006-present: USGS Coastal and Marine Hazards and Resources Program, Santa Cruz, CA, Principal Investigator of Landscape Response to Disturbance project

Editor-in-Chief, January 2019-present: Journal of Geophysical Research, Earth Surface

Postdoctoral Researcher, 2003-2006: USGS/UC Santa Cruz

Ph.D., Geology and Geophysics, 2003: MIT/Woods Hole Oceanographic Institution

B.S., Geological Sciences, 1997: Tufts University

Research Topics

Landscape Response to Climate Change

Climatic changes associated with modern global warming have been documented widely, but physical landscape responses are poorly understood. Landscape signals of modern climate change relate to human health and safety, infrastructure, water security, and ecosystems. Our project investigates landscape responses to modern climate change, primarily in the western US, focusing on slope failures, watershed sediment yields, river morphology, and aeolian (wind-blown) sediment mobilization.

Post-Fire Sediment Mobilization

Watershed sediment yields increase after fire, but by how much and with what driving factors is not well understood for some regions. Our group studies several CA wildfires, monitoring sediment yield and related processes. We have active research on the 2018 Carr Fire, 2020 CZU and 2020 Dolan Fires.

Effects of Large Dam Removal

Colleagues and I have studied river response to large dam removals on the Elwha River, WA, and Carmel River, CA, and study the Klamath River (CA and OR) preparing for dam removals there. I helped lead a USGS Powell Center working group on the state of dam-removal science.

Landscape Response to Hydroclimatic Extremes

Western US landscapes export large sediment fluxes, due to steep terrain, tectonic activity, and potential for extreme rain. I study landscape response to hydroclimatic disturbances—drought and extreme rain. We studied sediment export from the San Lorenzo River, CA, from record rainfall in 2017; and debris flows caused by intense rain in 2018 over the Tuolumne basin. Understanding such disturbances is critical to constraining effects of extreme events on landscapes and sediment budgets.

Landscape Evolution in the Colorado River Ecosystem

From 2003 to 2017 I studied connectivity among fluvial, aeolian, and hillslope processes in the Colorado River corridor, AZ. Since 1963, dam operations have altered flows and sediment supply in the Colorado River, Grand Canyon National Park. Loss of sandbars in the dammed river reduces windblown sand supply to aeolian dunes, affecting archaeological-site stability and ecosystem properties.

Aeolian Landscape Stability

Our work quantified sediment accumulation and landscape stability in areas of the California desert considered for solar-energy projects. I also studied aeolian landscapes on the Navajo Nation, where during drought wind-blown sand mobility has destabilized ground surfaces, endangering housing and transportation, jeopardizing grazing lands, and impacting air quality.