M7.0 Papua, Indonesia, Earthquakes of 16 June 2010

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The magnitude 7.0 Papua, Indonesia earthquake of June 16, 2010, 03:16 UTC, occurred as a result of strike-slip faulting. The causative fault has not yet been identified, though the radiation pattern of seismic waves generated by the earthquake is consistent with either left-lateral faulting on an east-northeast striking fault or right-lateral faulting on a north-northwest striking fault.

Eastern Indonesia is characterized by complex tectonics in which motions of numerous small plates are accommodating large-scale convergence between the Australia, Pacific, and Eurasia plates. The earthquake lies near the boundary between what some workers term the Birds Head microplate and the Maoke microplate. This microplate boundary has been modeled as an east-northeast trending boundary that accommodates approximately 80 mm/year left-lateral motion. The focal mechanism of today's earthquake is consistent with it occurring within the proposed microplate boundary, either as left-lateral slip on a boundary-parallel fault or as right-lateral slip on a conjugate fault that is tectonically related to the microplate boundary. In light of large uncertainty in tectonic modeling of eastern Indonesia, however, any particular hypothesis for the causative fault of the earthquake must be regarded as tentative pending further study.

Eastern Indonesia experiences many strong earthquakes. Since 1979, the region within 300 km of the main-shock of June 16, 2010, has experienced eight other earthquakes with magnitude larger than 7, the largest of which had magnitude 8.2.