Imaging Volcanic Deformation Over Aleutian Islands

Zhong Lu(1) , Dan Dzurisin(2) , Chuck Wicks(2) , John Power(2) , Ohig Kwoun(1) , and Russ Rykhus(1)

(1) SAIC, USGS/EROS, 47914 252nd Street, Sioux Falls, SD, United States
(2) USGS, Volcano Hazards Program, USA, United States

Abstract

Interferometric synthetic aperture radar (InSAR) is capable of measuring ground-surface deformation with centimeter to subcentimeter precision and spatial resolution of tens-of-meters over relatively large regions under all-weather conditions. The spatial distribution of surface deformation data, derived from InSAR images, enables the exploration of detailed mechanical models to enhance the study of volcanic and tectonic processes. This paper summarizes our InSAR studies of more than a dozen Alaskan volcanoes, associated with both eruptive and non-eruptive activity. These examples include the pre-eruption inflation, co-eruption deflation, and post-eruption inflation at Okmok volcano; magmatic intrusion and the associated tectonic stress release at Akutan volcano; progressive aseismic inflation of Westdahl volcano; magmatic intrusion at Mount Peulik volcano and its relation to an earthquake swarm 30 km away; magmatic intrusion at Makushin volcano associated with a small eruption in 1995; complex patterns of transient deformation during and after the 1992-1993 eruption at Seguam volcano; surface subsidence caused by a decrease in pore fluid pressure in an active hydrothermal system beneath Kiska volcano; compaction of young pyroclastic flow deposits at Augustine volcano; persistent volcano-wide subsidence at Aniakchak volcano; and a lack of expected deformation associated with recent eruptions at Shishaldin, Pavlof, Cleveland and Korovin volcanoes. We conclude that the deformation patterns and the associated magma supply mechanisms over Aleutian volcanoes are diverse and vary between volcanoes. These studies demonstrate that InSAR can improve our understanding on how the Aleutian volcanoes work and enhance our capability to predict future eruptions and the associated hazards.

 

Workshop presentation

 

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