25‐year history of volcano magma supply in the east‐central Aleutian arc, Alaska

Abstract:

Using ~25 years of GPS and InSAR observations and the time‐dependent inversion filter, we invert for the volume change history of three active volcanoes in the east‐central Alaska Aleutian arc, and the secular velocity of the region. The inferred time‐dependent volume change shows 1) two exponentially decaying pulses followed by a nearly linear inflation period at Westdahl volcano; 2) multiple episodic inflation events at Akutan volcano; 3) transient volcanic inflation and long‐term deflation signals at Makushin volcano. Comparing our regional velocity estimates with recently published block models, we find a small signal that can be explained by slip deficit on the megathrust, either from a shallow (<20 km depth) almost fully‐locked zone or a weakly locked zone confined to 25‐50 km depth.