Diverse deformation patterns of Aleutian Volcanoes from satellite Interferometric Synthetic Aperture Radar (InSAR)

Abstract

Interferometric synthetic aperture radar (InSAR) is capable of measuring groundsurface deformation with centimeter-to-subcentimeter precision at a spatial resolution of tens of meters over a large region. With its global coverage and all-weather imaging capability, InSAR has become an increasingly important measurement technique for constraining magma dynamics of volcanoes over remote regions such as the Aleutian Islands. The spatial distribution of surface deformation data derived from InSAR images enables the construction of detailed mechanical models to enhance the study of magmatic processes. This paper summarizes the diverse deformation patterns of the Aleutian volcanoes observed with InSAR. These include the following: 1) inflation of Mount Peulik Volcano preceding a seismic swarm at nearby Becharof Lake in 1998; 2) persistent volcano-wide subsidence at Aniakchak and Fisher Volcanoes; 3) magmatic intrusion and associated tectonic stress release at Akutan Volcano; 4) magmatic intrusion at Makushin Volcano associated with a small eruption in 1995; 5) complex patterns of transient deformation during and after the 1992-93 eruption at Seguam Volcano; 6) subsidence caused by a decrease in pore fluid pressure in an active hydrothermal system beneath Kiska Volcano; and 7) lack of expected deformation associated with recent eruptions at Shishaldin, Pavlof, Cleveland, and Korovin Volcanoes. We also present preliminary InSAR results for the Katmai Volcano group, and Chiginagak and Dutton Volcanoes. These studies demonstrate that deformation patterns and associated magma supply mechanisms in the Aleutians are diverse and vary between volcanoes. These findings provide an improved understanding of magmatic plumbing systems in the Aleutians.

Continuing inflation at Three Sisters volcanic center, central Oregon Cascade Range, USA, from GPS, leveling, and InSAR observations

“…A better analog for the Three Sisters activity might be found at one or more volcanoes in the Aleutian arc, where InSAR studies have revealed numerous cases of ground deformation at relatively small volcanic centers (Lu et al 2007). Westdahl shield volcano, for example, re-inflated following its 1991-1992 effusive eruption at an exponentially declining rate with a 1/e decay constant of~6 yearssimilar to the 5.3 ± 1.1 years time constant for Three Sisters that we report here.…”

Radar image and data fusion for natural hazards characterisation

“…InSAR maps of inter-eruption deformation, the onset of which often precedes swarms of earthquakes and other eruption precursors, provide insights into the structure, magma plumbing system and the state of restless volcanoes (e.g. Lu 2007, 2007b. InSAR also can be used to image ground surface displacements before, during and after large seismic events -information that is essential for hazard assessment and postdisaster response efforts.…”

“…InSAR maps of co-eruption deformation provide information about eruption dynamics, including the eruption rate as a function of time (e.g. Dzurisin 2003, Lu et al 2007b. InSAR maps of inter-eruption deformation, the onset of which often precedes swarms of earthquakes and other eruption precursors, provide insights into the structure, magma plumbing system and the state of restless volcanoes (e.g.…”

Measurement and interpretation of subtle deformation signals at Unimak Island from 2003 to 2010 using weather model‐assisted time series InSAR

“…Fisher Caldera, which contains several active fumaroles and two large lakes, is one of the largest calderas in the Aleutian Islands [ Lu et al ., ] and is located east of Westdahl. The southern part of Fisher is covered by a thick layer of tephra, which offers the potential for achieving excellent coherence in InSAR studies.…”