Fluids are well known to influence earthquakes, yet rarely are earthquakes convincingly linked to precipitation. Weak modulation or limited data often leads to ambiguous interpretations. In contrast, here we find that shallow seismicity in the Sierra Nevada range near Long Valley Caldera is strongly modulated by snowmelt. Over 33 years, shallow seismicity rates were ~37 times higher during very wet periods versus very dry periods. Relative earthquake relocations from a swarm in 2017 reveal downward migration from ~1- to 3-km depth along a steeply inclined plane. Steeply dipping strata may provide high-permeability pathways and faulting plane. Here we combine the correlated seismicity and hydrologic time series with the propagation observed in the relatively relocated earthquakes. From this combined evidence, we infer that pressure diffusion from groundwater recharge dramatically accelerated shallow seismicity rates, causing seismic swarms unrelated to volcanic processes.
Citation Information
| Publication Year | 2019 |
|---|---|
| Title | Snowmelt-triggered earthquake swarms at the margin of Long Valley Caldera, California |
| DOI | 10.1029/2019GL082254 |
| Authors | Emily Montgomery-Brown, David R. Shelly, Paul A. Hsieh |
| Publication Type | Article |
| Publication Subtype | Journal Article |
| Series Title | Geophysical Research Letters |
| Index ID | 70222523 |
| Record Source | USGS Publications Warehouse |
| USGS Organization | Volcano Science Center |
Related Content
Emily Montgomery-Brown
Research Geophysicist, Volcano Geodesist
Paul Hsieh (Former Employee)
Scientist Emeritus
Related Content
- Connect
Emily Montgomery-Brown
Research Geophysicist, Volcano GeodesistPhonePaul Hsieh (Former Employee)
Scientist Emeritus