WITHDRAWN Assimilation of Vertical Land Movement Observations and Models to Support Sea Level Rise Planning Along the Shorelines of the Cascadia Subduction Zone
Description:
WITHDRAWN Deformation associated with the Cascadia Subduction Zone (CSZ) drives complex and highly variable patterns of vertical land movement (VLM), that can locally modify expected sea level trends, and therefore complicate the development of, and confidence in, sea level rise projections. Relative sea level projections for Washington State utilized vertical land movement estimates derived from multiple sources, including continuous GPS databases, a single-differencing approach using tide-gauge data, and repeat leveling of survey control monuments near highways.The observations were assimilated with a tectonic deformation model of the Cascadia Subduction Zone to develop a best-fit surface for the study area, along with its associated uncertainty. The best fit VLM surface and its uncertainty was principally guided by the observations; but in locations with sparse data, the tectonic deformation model dominates the fit of the surface. The results suggest considerable variability in coastal vertical land movement in coastal Washington State, ranging from 0-3 mm/yr over spatial scales of 10s-of-kms. Using a Monte Carlo approach, vertical land movement estimates and their uncertainties are integrated into sea level projections at high resolution, and the variability in vertical land movement translates into spatial differences in projected relative sea level change of ~0.3 m by 2100. The analysis was limited in a variety of ways, though: Perhaps most importantly the VLM estimates derived with this approach relied on interseismic VLM observations, and therefore did not model possible future VLM that might influence relative sea level along the shoreline of the CSZ. A new assessment, supported by NSF through the Cascadia CoPes Hub, uses more robust approaches, updated observational data sets, and will provide new insights about relative sea level patterns and projections across the entire shoreline of the CSZ, including a probabilistic approach to the impact of a megathrust earthquake. The work can provide a template for sea level rise planning in other regions of the world with active tectonic margins.
Session: Seismic Cycle-Driven Sea-Level Change Over Decades to Centuries: Observations and Projections [Poster Session]
Type: Poster
Date: 5/3/2024
Presentation Time: 08:00 AM (local time)
Presenting Author: Ian
Student Presenter: No
Invited Presentation:
Authors
Ian Miller Presenting Author Corresponding Author immiller@uw.edu University of Washington |
David Schmidt dasc@uw.edu University of Washington |
Anna Pearson aerp@uw.edu University of Washington |
Jeonghyeop Kim jeykim@uw.edu University of Washington |
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WITHDRAWN Assimilation of Vertical Land Movement Observations and Models to Support Sea Level Rise Planning Along the Shorelines of the Cascadia Subduction Zone
Category
Seismic Cycle-Driven Sea-Level Change Over Decades to Centuries: Observations and Projections