Mount Hobalt, an undersea volcano roughly km off the south coast of Lembata Island, Indonesia, erupted at about 7.15 am local time on Tuesday 20 August 2013 (around 11.15 pm on Monday 19 August, GMT), producing a column of ash rising 2 km above sea level. After the eruption the volcano was seen to emit bubbles for some time, and nearby seawater was observed to be stained yellow. While this eruption is not thought to have caused any problems for inhabitants of nearby islands, eruptions from Hobalt have in the past lead to tsunamis. The Pusat Vulkanologi dan Mitigasi Bencana Geologi (Center for Vulcanology and Geological Disaster Mitigation) is monitoring the situation.
The approximate location of Mount Hobalt. Google Maps.
Lembata sits on the northern part of the Timor Microplate; a small fragment of crust caught between the Banda Sea Plate to the north and the Australian plate to the south. Both these other plates are subducting beneath the Timor Plate, and as they sink into the Earth, melted by the friction and the heat of the planets interior. Some of this melted material then rises through the overlying plate, fueling the volcanoes of Flores, Timor and the neighboring islands.
See also Six people killed by eruption on Mount Rokatenda, Earthquake beneath the Banda Sea, Eruption on Mount Paluweh, Eruption on Mount Sirung and Eruptions on Batu Tara.
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