Sponsor
We thank the Bonneville Power Administration (BPA project 2002-077-00) and BPA Estuary Lead Jason Karnezis for funding most of this work. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Modeling was performed using PNNL Institutional Computing at Pacific Northwest National Laboratory. SAT was partially funded by National Science Foundation project 2013280. We acknowledge Tim Carlson of PNNL Institutional Computing for helping set up the Delft3D-FM model used in this study.
Published In
Geophysical Research Letters
Document Type
Article
Publication Date
6-2023
Subjects
Tides, Water levels
Abstract
Subsidence after a subduction zone earthquake can cause major changes in estuarine bathymetry. Here, we quantify the impacts of earthquake-induced subsidence on hydrodynamics and habitat distributions in a major system, the lower Columbia River Estuary, using a hydrodynamic and habitat model. Model results indicate that coseismic subsidence increases tidal range, with the smallest changes at the coast and a maximum increase of ∼10% in a region of topographic convergence. All modeled scenarios reduce intertidal habitat by 24%–25% and shifts ∼93% of estuarine wetlands to lower-elevation habitat bands. Incorporating dynamic effects of tidal change from subsidence yields higher estimates of remaining habitat by multiples of 0–3.7, dependent on the habitat type. The persistent tidal change and chronic habitat disturbance after an earthquake poses strong challenges for estuarine management and wetland restoration planning, particularly when coupled with future sea-level rise effects.
Rights
Copyright (c) 2023 The Authors
This work is licensed under a Creative Commons Attribution 4.0 International License.
Locate the Document
DOI
10.1029/2023GL103017
Persistent Identifier
https://archives.pdx.edu/ds/psu/40611
Citation Details
Brand, M. W., Diefenderfer, H. L., O’Connor, J. E., Borde, A. B., Jay, D. A., Al‐Bahadily, A., ... & Talke, S. A. (2023). Impacts of a Cascadia subduction zone earthquake on water levels and wetlands of the lower Columbia River and estuary. Geophysical Research Letters, 50(14), e2023GL103017.