T208 Earthquakes and Deformation in Eastern North America and Other Continental Interiors: What We Know, What We Don’t, What We Think, and Which Is Which?

Tuesday, 6 November 2018
1:30 PM - 5:30 PM
Room 238-239

DOES LONG-TERM FAULT MEMORY CONTRIBUTE TO THE SPACE-TIME VARIABILITY OF CONTINENTAL INTRAPLATE SEISMICITY?

Paper number: T208-1
Program: Technical Sessions
Time: 1:30 PM – 1:45 PM

Authors

Abstract

Large earthquakes in continental interiors show complex space-time variability quite different from behavior at plate boundaries. Fault zones tend to have clusters of earthquakes separated by long quiescent periods, and seismicity seems to roam between faults. As a result, traditional concepts like recurrence intervals and seismic gaps can be of only limited use, posing major challenges for hazard assessment. Although the mechanics involved are unclear, it seems likely to involve interactions between fault systems that jointly accommodate slow tectonic loading. Here, we explore the possible contribution of another process that we call Long-Term Fault Memory (LTFM). LFTM is a modified earthquake cycle model where the probability of an earthquake increases with time until one happens, after which the probability decreases, but not necessarily to zero. In this way, the probability can remain higher than the long-term average and clusters of events can result. We have used LFTM to simulate paleoearthquake records from Pallett Creek on the San Andreas Fault and the Cascadia Subduction Zone. Here we apply LTFM to records from continental interiors, including a particularly long record from the Cadell fault in intraplate Australia. We will explore similarities and differences between the application of LTFM to plate boundaries and intraplate regions.

Geological Society of America Abstracts with Programs. Vol. 50, No. 6

doi: 10.1130/abs/2018AM-320621

© Copyright 2018 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.