The Aleutian Earthquake of June 10, 1996 (Mw 7.9) ruptured parts of both the Andreanof and Delarof Segments

Abstract

The epicenter of the Aleutian earthquake of June 10, 1996, is located in the Delarof segment where a large subduction earthquake is expected. However, the aftershock area of the earthquake is not only in the Delarof segment but also in the Andreanof segment where the 1986 Andreanof earthquake occurred previously. We estimate the fault parameters of the 1996 earthquake by numerically computing the tsunami and comparing the waveforms with that recorded at Adak. The fault width is 30 km or less, and the average slip is about 4 m. The observed far‐field tsunamis around the Pacific are also explained by the synthetic tsunami computed using the above fault parameters. The results indicate that the 1996 earthquake ruptured parts of both the Delarof and Andreanof segments. However, the 1996 earthquake did not rupture the region of the largest moment release by the 1986 earthquake.