A fluid-driven earthquake swarm on the margin of the Yellowstone caldera
Over the past several decades, the Yellowstone caldera has experienced frequent earthquake swarms and repeated cycles of uplift and subsidence, reflecting dynamic volcanic and tectonic processes. Here, we examine the detailed spatial-temporal evolution of the 2010 Madison Plateau swarm, which occurred near the northwest boundary of the Yellowstone caldera. To fully explore the evolution of the swarm, we integrated procedures for seismic waveform-based earthquake detection with precise double-difference relative relocation. Using cross-correlation of continuous seismic data and waveform templates constructed from cataloged events, we detected and precisely located 8710 earthquakes during the three-week swarm, nearly four times the number of events included in the standard catalog. This high-resolution analysis reveals distinct migration of earthquake activity over the course of the swarm. The swarm initiated abruptly on January 17, 2010 at about 10 km depth and expanded dramatically outward (both shallower and deeper) over time, primarily along a NNW-striking, ~55º ENE-dipping structure. To explain these characteristics, we hypothesize that the swarm was triggered by the rupture of a zone of confined high-pressure aqueous fluids into a pre-existing crustal fault system, prompting release of accumulated stress. The high-pressure fluid injection may have been accommodated by hybrid shear and dilatational failure, as is commonly observed in exhumed hydrothermally affected fault zones. This process has likely occurred repeatedly in Yellowstone as aqueous fluids exsolved from magma migrate into the brittle crust, and it may be a key element in the observed cycles of caldera uplift and subsidence.
Citation Information
Publication Year | 2013 |
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Title | A fluid-driven earthquake swarm on the margin of the Yellowstone caldera |
DOI | 10.1002/jgrb.50362 |
Authors | David R. Shelly, David P. Hill, Frederick Massin, Jamie Farrell, Robert B. Smith, Taka'aki Taira |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Journal of Geophysical Research B: Solid Earth |
Index ID | 70048350 |
Record Source | USGS Publications Warehouse |
USGS Organization | Volcano Science Center |