GPS, IfSAR Track Renewed Inflation of Long Valley Caldera, California

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The  20- x 10-mile Long Valley caldera in eastern California formed from a “super eruption” about 760,000 years ago, and is considered a Very High Threat volcano by the USGS Volcano Hazards Program. Since 1978, several periods of seismic and deformation unrest have been detected at this well-monitored volcano but have not resulted in eruptions. A period of slow inflation concentrated within the Long Valley caldera began in late 2011, coinciding with renewed swarm seismicity. Analysis of the deformation over 3 years by a combination of GPS and Interferometric Synthetic Aperture Radar (IfSAR) (TerraSAR-X) data processed using a persistent scatterer technique allows a comparison of the present uplift episode with past episodes, shows good correlation with ground-based deformation measurements, and defines a persistent, elongated spheroidal magma reservoir ~7 km (~4.3 mi) beneath the resurgent dome through modeling. IfSAR aids in developing a regional picture of baseline unrest, which will help volcanologists characterize the range of deformation activity in the Long Valley caldera.

http://onlinelibrary.wiley.com/doi/10.1002/2015GL064338/full

TerraSAR-X deformation velocities determined from 22 interferograms spanning 2011 to 2014. The line-of-sight velocities show inflation of up to 15 mm/yr under Long Valley's resurgent dome. For orientation, Mono Lake, California, is located in the northwest corner of the image, and north is at the top of the image.

TerraSAR-X deformation velocities determined from 22 interferograms spanning 2011 to 2014. The line-of-sight velocities show inflation of up to 15 mm/yr under Long Valley's resurgent dome. For orientation, Mono Lake, California, is located in the northwest corner of the image, and north is at the top of the image.

Platform
Author Name
Emily Montgomery-Brown
Author Email
emontgomery-brown@usgs.gov