Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published August 2004 | public
Journal Article

Surveying Volcanic Arcs with Satellite Radar Interferometry: The Central Andes, Kamchatka, and Beyond


Satellite Interferometric Synthetic Aperture Radar (InSAR) permits both synoptic and detailed surveys of magmatic activity in volcanic arcs. To illustrate this capability, we summarize here the results of an extended study of inferred magmatic activity in the central Andean arc (Pritchard and Simons, 2002; Pritchard, 2003; Pritchard and Simons, 2004), as well as new results from Kamchatka. In the central Andes, encompassing parts of Peru, Bolivia, Chile, and Argentina, we have observed ~900 volcanoes between 1992 and 2003 and found four previously undocumented sources of deformation. Coupled with surveys in other arcs, this deformation indicates that short-lived pulses of magma movement are common, although the relation of these movements to eruptive activity is unclear. In fact, no co-eruptive deformation was detected from eruptions at four other Andean volcanoes. In Kamchatka, the limits of current InSAR satellites are apparent in terms of the quality of the measurements and coverage of the arc. Nonetheless, we observe subsidence associated with a large lava flow that erupted 28 years ago and inflation of a geothermally active caldera. While a global inventory of volcanic arcs is impossible with current datasets, InSAR is a critical tool for understanding volcanic hazard at most of the world's poorly monitored subaerial volcanoes as well as for searching for large magma reservoirs.

Additional Information

© 2004 The Geological Society of America, Inc. Manuscript submitted January 13, 2004; revised manuscript submitted May 5, 2004; accepted May 27, 2004. We are grateful for the comments of Science Editor K. Howard and reviewers D. Dzurisin, S. Jonsson, S. McNutt, and Z. Lu. ERS SAR imagery was acquired under a Category 1 research project from the European Space Agency and was processed with the Caltech/JPL ROI PAC software (Rosen et al., 2004). RADARSAT and some ERS SAR data were provided by the Alaska SAR facility, and we thank E. Fielding, E. Price, and V. Wolf for helping us find and process this data. Digital Elevation Models from the Shuttle Radar Topography Mission at 90 m per pixel resolution were supplied courtesy of NASA. The GMT program was used to create several figures (Wessel and Smith, 1998). Pritchard was partly supported by a Hess Fellowship from Princeton University. Contribution number 9073 of the Division of Geological and Planetary Science, Seismological Laboratory, California Institute of Technology.

Additional details

August 22, 2023
October 24, 2023