Surface deformation associated with the March 1996 earthquake swarm at Akutan Island, Alaska, revealed by C-band ERS and L-band JERS radar interferometry

Canadian Journal of Remote Sensing
By: , and 

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Abstract

In March 1996, an intense earthquake swarm beneath Akutan Island, Alaska, was accompanied by extensive ground cracking but no eruption of Akutan volcano. Radar interferograms produced from L-band JERS-1 and C-band ERS-1/2 images show uplift associated with the swarm by as much as 60 cm on the western part of the island. The JERS-1 interferogram has greater coherence, especially in areas with loose surface material or thick vegetation. It also shows subsidence of similar magnitude on the eastern part of the island and displacements along faults reactivated during the swarm. The axis of uplift and subsidence strikes about N70°W, which is roughly parallel to a zone of fresh cracks on the northwest flank of the volcano, to normal faults that cut the island and to the inferred maximum compressive stress direction. A common feature of models that fit the deformation is the emplacement of a shallow dike along this trend beneath the northwest flank of the volcano. Both before and after the swarm, the northwest flank was uplifted 5–20 mm/year relative to the southwest flank, probably by magma intrusion. The zone of fresh cracks subsided about 20 mm during 1996–1997 and at lesser rates thereafter, possibly because of cooling and degassing of the intrusion.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Surface deformation associated with the March 1996 earthquake swarm at Akutan Island, Alaska, revealed by C-band ERS and L-band JERS radar interferometry
Series title Canadian Journal of Remote Sensing
DOI 10.5589/m04-054
Volume 31
Issue 1
Year Published 2005
Language English
Publisher Taylor and Francis
Contributing office(s) Volcano Hazards Program, Earth Resources Observation and Science (EROS) Center
Description 14 p.
First page 7
Last page 20
Country United States
State Alaska
Other Geospatial Akutan Island
Online Only (Y/N) N
Additional Online Files (Y/N) N