Tuesday 11 December 2012

Earthquake beneath the Banda Sea.

On Tuesday 11 December 2012, slightly before 2.00 am local time (slightly before 5.00 pm on Monday 10 December, GMT), a magnitude 7.1 Earthquake occurred beneath the Banda Sea, about 600 km north of Darwin, measured by the United States Geological Survey as being at a depth of 159.3 km and by Geoscience Australia as at a depth of 151 km. This is a large Earthquake, but quite a long way offshore and very deep, so only a few remote islands are likely to have been effected.

Map showing the area effected by the 11 December quake. Areas within the black circle are likely to have felt shaking and areas within the red circle may have suffered damage. Geoscience Australia.

The Banda Sea is underlain by two tectonic plates, the Banda Sea Plate and the Timor Plate; two small plates caught between the colliding Eurasian, Pacific and Australian Plates. The Timor Plate is being subducted beneath the Banda Sea Plate. As it sinks into the Earth the subducting plate is being melted by the heat of the planets interior; some of the melted material then rises through the overlying Banda Sea Plate, fueling volcanism on a number of islands in the region. This is not a smooth process, and the plates frequently stick together then break apart as the pressure builds up, fueling Earthquakes in the region.

See also Eruption on Mount PaluwehEruptions on Batu Tara and Earthquakes on Sciency Thoughts YouTube.

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