Seismicity in Idaho and Montana Triggered by the Denali Fault Earthquake: A Window into the Geologic Context for Seismic Triggering
- Creators
- Husker, Allen L.
- Brodsky, Emily E.
Abstract
We present a case study of dynamically triggered seismicity in Idaho and western Montana from the 2002 M_W 7.9 Denali fault earthquake to investigate the relationship between measured geological discriminants and propensity for triggering. We first establish triggering. We find events that are not reported in the Advanced National Seismic System catalog in Idaho and Yellowstone following the Denali fault earthquake by filtering broadband waveforms. An M_L 4.6 earthquake is discovered near New Meadows, Idaho, during the passage of the Rayleigh waves and another earthquake probably located near Yellowstone. We find that central western Idaho and Yellowstone have statistically significant seismicity increases by applying a β test to the cataloged events in the 48 hr after the Denali fault earthquake in Idaho and surrounding regions. We also find that Pine, Idaho, may have triggered events, but the measurement is not robust because of uncertainty in the background seismicity rate. Both central western Idaho and Yellowstone triggered previously during the 1992 Landers earthquake. We then try to determine the local geological conditions necessary for triggered seismicity to occur. Geothermal regions with high total dissolved solids and background seismicity appear to be favorable conditions to trigger earthquakes in the study.
Additional Information
© 2004 Bulletin of the Seismological Society of America. Manuscript received 13 February 2004. We thank Michael Stickney for providing resources and the Montana velocity model, Jim Zollweg for providing data from the bsu seismic network, and Paul Davis, Stephanie Prejean, Karen Felzer, and Rebecca Harrington for discussions. We also thank the neic and Berkley Data Center hosting the anss for catalog data, and the usnsn and uo networks for waveform data. This work was in part supported by National Science Foundation Grant EAR-0238455.Attached Files
Published - S310_946b_04618.pdf
Files
Name | Size | Download all |
---|---|---|
md5:fae3dd398943b6d2a8560240677b6137
|
332.5 kB | Preview Download |
Additional details
- Eprint ID
- 109066
- Resolver ID
- CaltechAUTHORS:20210511-082511999
- EAR-0238455
- NSF
- Created
-
2021-05-12Created from EPrint's datestamp field
- Updated
-
2021-05-12Created from EPrint's last_modified field