Dynamics and rapid migration of the energetic 2008–2009 Yellowstone Lake earthquake swarm
Article first published online: 13 OCT 2010
Copyright 2010 by the American Geophysical Union.
Geophysical Research Letters
Volume 37, Issue 19, October 2010
How to Cite
2010), Dynamics and rapid migration of the energetic 2008–2009 Yellowstone Lake earthquake swarm, Geophys. Res. Lett., 37, L19305, doi:10.1029/2010GL044605., , , , and (
- Issue published online: 13 OCT 2010
- Article first published online: 13 OCT 2010
- Manuscript Accepted: 23 AUG 2010
- Manuscript Revised: 17 AUG 2010
- Manuscript Received: 6 JUL 2010
 Yellowstone National Park experienced an unusual earthquake swarm in December–January, 2008–2009 that included rapid northward migration of the activity at 1 km per day and shallowing of the maximum focal depths from 12 to 2 km beneath northern Yellowstone Lake. The swarm consisted of 811 earthquakes, 0.5 < MW < 4.1, aligned on a N–S 12-km-long vertical plane of hypocenters. The largest earthquake of the swarm had a 50% tensile crack-opening source determined by a full waveform inversion that we interpret as a magmatic expansion component. In addition, GPS data revealed E–W crustal extension coincident with the swarm. Modeling of GPS and seismic data is consistent with E–W opening of ∼10 cm on a N–S striking vertical dike. Our interpretation is that the swarm was induced by magmatic fluid migration or propagation of a poroelastic stress pulse along a pre-existing fracture zone.