M 7.5 - 155 km E of Kendari, Indonesia

  • 2001-10-19 03:28:44 (UTC)
  • 4.102°S 123.907°E
  • 33.0 km depth

Tectonic Summary

The October 19, 2001, M 7.5 Banda Sea earthquake occurred as the result of shallow strike-slip faulting in the tectonically complex region of eastern Indonesia. Focal mechanism solutions indicate that rupture occurred on either a left-lateral east-west-striking fault or on a right-lateral north-south-trending fault. At the location of the earthquake, the Australia plate moves northward relative to the Sunda plate at a velocity of about 75 mm/yr, driving the motion of small microplates in eastern Indonesia that together accommodate the overall convergence between these two plates and the Philippine Sea and Pacific plates farther to the north and east. This earthquake occurred close to the boundary between two of these smaller microplates (oriented north-south), called the Banda Sea and Molucca Sea microplates.

This large, strike-slip faulting event is one of many historical large earthquakes in this tectonically complex region. Within 400 km of the October 19th event, there have been five other earthquakes of M 7.0+ over the preceding 40 years. The two largest were a deep-focus M 7.9 earthquake in June 1996 and a M 8.2 earthquake in January 1965. Despite having greater magnitudes, these events are not known to have caused fatalities, while shallow earthquakes in November 1998 (M 7.7) and May 2000 (M 7.6), both roughly 240 km to the north of the October 19 event, resulted in at least 30 fatalities each.

Hayes et al. (2016) Tectonic summaries of magnitude 7 and greater earthquakes from 2000 to 2015, USGS Open-File Report 2016-1192. (5.2 MB PDF)

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