Tokyo VAAC reported a relatively large explosive event at the growing Japanese island and volcano, Nishino-shima (Pacific Ocean), on June 29, 2014. The eruption occurred at 22:43 UTC; ash plume rose up to 3 km (10 000 ft) altitude and drifted northeast.
Volcanic ash plume was not detected on satellite imagery.
The small island of Nishino-shima ("western island") is a volcanic island and a part of the Volcano Islands arc. The island was enlarged in 1974 after fresh eruptions created a new section of the island. Another eruption that began in November 2013 created a new island, named Niijima, which connected with Nishino-shima on December 25, 2013, and further enlarged the island:
Acquired on December 8, 2013. Image credit: NASA / Earth Observatory (ALI - EO-1).
Acquired on December 24, 2013. Image credit: NASA / Earth Observatory (ALI - EO-1).
Nishino-shima is the summit of a massive submarine volcano that has prominent satellitic peaks to the S, W, and NE. The summit of the southern cone rises to within 214 m of the sea surface 9 km SSE.
Photographs and video taken from a Japanese Coast Guard helicopter on June 11 and 13 revealed continuing eruptive activity. Steaming along the shoreline indicated at least two locations with active, or recently active, lava ocean entries, possibly tube-fed since no surface incandescence was visible. Night video clearly showed an active lava flow and ocean entry being supplied from lava fountaining out of a cinder cone.
A significant steam plume was rising from the center of the lava shield from hot tephra deposits over a broad area rather than a crater. However, pulsating tephra ejections and distinctly brown ashplumes were rising from two smaller craters. An incandescent lava lake was visible in one of the small craters on both days.
The following video was recorded by Japanese Coast Guard on June 13, 2014:
Video courtesy of Japanese Coast Guard
Featured image: Nishino-shima on June 13, 2014. Image credit: Japanese Coast Guard