Tsunami Hazard Assessment of Portions of Island and Skagit Counties, Washington

Randall J. LeVeque, Loyce M. Adams, and Frank I. Gonzalez
University of Washington

This webpage documents the results of a study supported by the Washington State Emergency Management Division of the tsunami hazard along the coast of portions of Island and Skagit Counties, including the entire coast of Whidbey Island and the Skagit River Delta. Earthquake sources from the Seattle Fault, the Cascadia Subduction Zone, and the Aleutian Subduction Zone were considered. Results include inundation depths and times of arrival that will be useful to coastal communities, as well as tsunami current speeds and momentum flux. GeoClaw Version 5.6.0 was used for the modeling, with some modifications as described in the appendices of the report and the pages below.


Study region

The study region was subdivided into 6 polygons for individual GeoClaw runs, as denoted in the figure below. Note that areas colored pink are where the topography is below MHW, but where the land was determined to be initially dry (behind dikes and/or levies).

Results and Plots

To download:

Jupyter notebook output:

The Jupyter notebooks themselves can be found in the code repository linked above. These notebooks contain Python code and the resulting output and plots, along with discussion of what is being done.