Basement Structure of the Southern Fairbanks Seismic Zone and Its Relation to Large (M>6) Earthquakes (1929-1947)
Session: How Should Low-Probability Earthquakes be Considered in Hazard Assessments?
Type: Oral
Date: 4/23/2021
Presentation Time: 10:00 AM Pacific
Description:
We are using topographic, gravity and aeromagnetic information to better define the basement structure of the southern Fairbanks Seismic Zone (SFSZ), a region that could represent northward growth of the Northern Foothills Fold and Thrust Belt (NFFTB), serving to accommodate additional contraction in central Alaska north of the Denali fault. At least 5 earthquakes of M>6 have occurred within the SFSZ between 1929 and 1947. Comparison of waveforms of the smaller events to the well-studied October 16, 1947 (M~7.1) mainshock suggest northward directed thrusting in an area with limited surficial geology. Aeromagnetic data indicate these events may have nucleated at the edges of east-west trending magnetic highs, while topographic information suggests changes in the character of stream erosion within the vicinity of the 1947 sequence. We will evaluate 4 gravity/aeromagnetic/topographic profiles extending from the Denali fault across the NFFTB and SFSZ to the Tanana River to determine the extent of thrusting within this region.
Presenting Author: Diane I. Doser
Student Presenter: No
Authors
Diane Doser Presenting Author Corresponding Author doser@utep.edu University of Texas at El Paso |
Mark Baker bakergrd@cs.com Geophysical Consultant |
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Basement Structure of the Southern Fairbanks Seismic Zone and Its Relation to Large (M>6) Earthquakes (1929-1947)
Session
General Session