Nishino-Shima volcano (Izu Islands, Japan): ash plumes from explosive activity
Sunday Jan 26, 2014 11:52 AM | BY: T
The former new island off Nishino-Shima seen on 20 Jan 2014(Japan Coast guard)
Map showing the evolution of the new island between 21 Nov (shortly after its birth), 26 Dec (touching the main island) and 20 Jan 2014
The volcano continues to enlarge the island with lava flows, but seems to have increasingly explosive activity as well. Ash plumes to altitudes of 4,000 ft (1.2 km) were reported during the past days. These could have originated from more violent water-magma interaction (phreatomagmatic activity) or simply stronger strombolian explosions.
The 2 active vents of Niishima (the left one showing spattering of liquid lava) and an active flow
As recent imagery by the Japanese Coast guard shows, new lava flows continued to effuse at low rate and slowly increase the size of what started as a new island, now merged and surpassed in size the older Nishino-Shima island. On the new land, 2 vents remain active, one of which was observed to produce mild strombolian explosions and spattering of liquid lava.
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Wednesday, Jan 15, 2014
The Japanese Coast Guard made an overflight yesterday and published the attached picture of the (former new) island. It seems that while it is still might be effusing some lava that form flows reaching the eastern shore in the bay near the vents, the rate of lava effusion/growth has slowed down. No large changes of the island appear visible when compared to the images a week ago.
Monday, Jan 06, 2014
The new island that had "touched" Nishino-Shima has continued to grow and the two islands form now a coherent single one, with a interesting "butterfly" shape. This might of course change quickly again as well. There are now no traces left of the beach and the little colored lake that existed a week ago when the two islands started to merge. ...
Friday, Dec 27, 2013
The recently born new Niijima island merged with the main island Nishino-Jima yesterday. Both are in fact two summits of the same volcanic edifice. Activity continues to enlarge the new land by lava flows and occasional strombolian explosions. ...
Monday, Dec 23, 2013
The new volcanic island continues to grow thanks to active lava flows and has now reached more than 50 meters and surpassed its mother island in height. Its continuing growth also makes it be at only about 50 meters shallow water distance from the Nishin-Jima island and it seems it might merge with it, rather than remaining an own new island, if activity continues. ...
Monday, Dec 16, 2013
Activity continues at the new island and has apparently picked up in strength again. Lava flows have created a significant new delta of new land during the past 3 days, enlarging the island to a current width measuring approx. 400 (E-W) by 300 (N-S) meters. ...
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