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Catalog of Coseismic Displacements Across Alaska

Description: 

A significant number of moderate to large earthquakes have occurred across Alaska over the last two decades, with each event causing permanent coseismic and/or transient postseismic displacements over a large area. At the time of the 2002 Denali fault earthquake, there were very few continuous GNSS sites across Alaska, so most data for that event came from campaign surveys. The development of the Plate Boundary Observatory (now Network of the Americas, NOTA) starting in 2004 substantially increased the number of continuous sites, making it much easier to resolve the effects of these earthquakes through space and time. For example, the recent Simeonof (2020, MW7.8) and Chignik (2021, MW8.2) events on the subduction interface offshore the Alaska Peninsula caused detectable coseismic displacements as far north as the Seward Peninsula. Prior to the installation of NOTA, this deformation would not have been captured. Without a robust network of continuous GNSS sites along the Alaska Peninsula, it would have been extremely difficult to separate the coseismic and postseismic effects from the closely spaced Simeonof, 2020 M7.6 Sand Point, and Chignik events. Capitalizing on the improved data resolution, we present a catalog of observed and model displacements from the most important earthquakes in Alaska over the last two decades.

Session: Crustal Deformation and Seismic Hazard in Western Canada, Cascadia and Alaska [Poster]

Type: Poster

Date: 4/20/2023

Presentation Time: 08:00 AM (local time)

Presenting Author: Jeffrey T. Freymueller

Student Presenter: No

Invited Presentation: 

Authors