Updating the crustal fault model for the 2023 National Seismic Hazard Model for Alaska

By: , and 
Edited by: Natalia A. RuppertM. Jadamec, and Jeffery T. Freymueller

Metrics

1
Crossref references
Web analytics dashboard Metrics definitions

Links

Abstract

We present the crustal fault model for Alaska, based on geologic observations, as a primary input for the 2023 revision of the U.S. Geological Survey National Seismic Hazard Model. We update the 2013 Alaska Quaternary fault and fold database to produce a simplified model of 105 fault sections and four fault zone polygons with basic geologic parameters including slip sense and rate. Significant updates include the following: (1) a slip rate of ∼53 mm/year on the Queen Charlotte Fault indicating it accommodates all of the plate boundary motion; (2) quantified slip rates on megathrust splay faults in the southern Prince William Sound region and near Kodiak Island; (3) improved details of structures in the Chugach-St. Elias orogen; (4) revision of the Castle Mountain Fault from right-lateral slip to a predominantly reverse fault; (5) improved Interior Alaska tectonic models that clarify relationships between the Denali, Totschunda, and thrust faults on both sides of the Alaska Range; (6) identified large earthquake sources in the eastern Brooks Range; and (7) omission of the Chatham Strait section of the Denali Fault. The fault model underscores that the collision of the Yakutat microplate is the dominant driver of active crustal faulting in most of Alaska.

Suggested Citation

Haeussler, P., Bender, A., Powers, P.M., Koehler, R.D., Brothers, D., 2024, Updating the crustal fault model for the 2023 National Seismic Hazard Model for Alaska, chap. 4 of Tectonics and seismic structure of Alaska and northwestern Canada: EarthScope and beyond, p. 85-127, https://doi.org/10.1002/9781394195947.ch4.

Study Area

Publication type Book chapter
Publication Subtype Book Chapter
Title Updating the crustal fault model for the 2023 National Seismic Hazard Model for Alaska
Chapter 4
DOI 10.1002/9781394195947.ch4
Publication Date December 13, 2024
Year Published 2024
Language English
Publisher American Geophysical Union
Contributing office(s) Alaska Science Center Geology Minerals
Description 43 p.
Larger Work Type Book
Larger Work Subtype Monograph
Larger Work Title Tectonics and seismic structure of Alaska and northwestern Canada: EarthScope and beyond
First page 85
Last page 127
Country Canada, United States
State Alaska, Yukon
Additional publication details