December 4, 2025 - Cascadia CoPes Hub Virtual Seminar Series

Title “Increased flood exposure in the Pacific Northwest following earthquake-driven subsidence and sea-level rise”.

Abstract: Climate-driven sea-level rise is increasing flood risks worldwide, but sudden land subsidence from great (>M8) earthquakes remains an overlooked factor. Along the Washington, Oregon, and northern California coasts, the next Cascadia subduction zone (CSZ) earthquake could cause 0.5-2 m of rapid subsidence, dramatically expanding floodplains and exposing communities to heightened flooding hazards.This talk explores the coastal geologic methods used to estimate coseismic subsidence along the CSZ, and then quantifies potential floodplain expansion across 24 Cascadia estuaries under low (~0.5 m), medium (~1 m), and high (~2 m) earthquake-driven subsidence scenarios—both today and by 2100, when compounded by climate-driven sea-level rise. We will also explore the implications for residents, infrastructure, and decision-makers preparing for the intersection of seismic and climate hazards.

Bio: Dr. Tina Dura leads the Coastal Hazards Lab at Virginia Tech (2019-present). Dr. Dura’s research program in coastal hazards employs subduction zone paleogeodesy, which combines the methods of coastal stratigraphy, sedimentology, micropaleontology, paleoseismology, geophysical and sediment transport modeling, and sea-level research to reconstruct long-term histories of coseismic vertical deformation and tsunami inundation along subduction zone coastlines. Dr. Dura has authored >30 peer-reviewed journal articles that have reconstructed >5,000 yearlong earthquake and tsunami records, redefined the spatial and temporal variability of past subduction zone earthquakes, and helped better assess future subduction zone hazards along coastlines around the world.