Shindake Volcano, on the island of Kuchinoerabu in the northern Ryukyu Islands, began to erupt suddenly slightly before 10.00 am local time on Friday 29 May 2015, when a loud explosion, thought to be a phreatic event (explosion caused by hot magma coming into contact with liquid water and vaporizing it instantly) was heard, followed by the production of a 9 km high ash plume that drifted to the southeast. A number of small pyroclastic flows (avalanches of hot gas and ash) were detected on the southwest and northwest flanks of the volcano, with those on the northwest observed to reach the sea. Local authorities ordered the evacuation of all 141 people present on the island at the time (about a hundred locals and a few visitors) as a precaution, and only a single injury was reported, an elderly man who received minor burns (it is unclear if this was caused directly by the volcano or some accident during the evacuation). Following the evacuations the volcano has been monitored closely, with a 1.2 km ash column observed on 30 May and several small pyroclastic flows on the northwest, southwest and southeastern flanks of the volcano.
Ash column over Kuchinoerabu Island on 29 May 2015, observed from the neighbouring island of Yakushima. Itaru Takaku/Kyodo News.
Japan has a complex tectonic environment with four plates underlying parts of the Islands; the Pacific in the east and the Othorsk in the North, there are the Philipine Plate to the south and the Eurasian Plate to the West. All of these plates are moving in different directions, and some subducting beneath the islands, leaning to a complex tectonic situation where earthquakes and volcanoes are common.
The location of Kuchinoerabu Island. Google Maps.
Kuchinoerabujima lies at the northeast end of the Ryukyu Island Arc, which sits on top of the boundary between the Eurasian and Philippine Plates. The Philippine Plate is being subducted beneath the Eurasian Plate, in the Ryukyo Trench, to the Southeast of the Islands. As it is drawn into the interior of the Earth, the tectonic plate is partially melted by the heat of the Earth's interior, and liquid magma rises up through the overlying Eurasian Plate to form the volcanos of the Ryukyu Islands and Kyūshū.
See also...
The Japan Meteorological Agency recorded an eruption on Mount Furudake on Kuchinoerabujima, an island about 130 km south of Kagoshima, at about 12.25 pm local time on Sunday 3 August 2014. The eruption consisted of a single powerful explosion followed by...
On 9 August 2013 the Japan Meteorological Agency reported a 50 minute eruption on Sakurajima Volcano, which is one of Japan's most active and sits on an island in Kagoshima Bay, Kyushu Island, which produced a 3.5 km high ash column, as well as...
The Tokyo Volcanic Ash Advisory Center reported that a 1.5 km ash plume was sighted over Suwanosejima on 3 July 2013. Such events are frequent on Suwanosejima, a sparsely inhabited 8 km...
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