Japan Geoscience Union Meeting 2016

Presentation information


Symbol S (Solid Earth Sciences) » S-VC Volcanology

[S-VC47] Active volcanism

Tue. May 24, 2016 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall HALL6)

Convener:*Yosuke Aoki(Earthquake Research Institute, University of Tokyo), Yuta Maeda(Nagoya University)

5:15 PM - 6:30 PM

[SVC47-P20] Volcanic activity in Nishinoshima volcano 2013-2016

*tomozo Ono1, Taisei Morishita1, Shogo Hamasaki1, Kenji Nogami2 (1.Japan coast Guard, 2.Tokyo Institute of Technology)

Keywords:volcano, Nishinoshima

Since activity starting on November 20, 2013, a volcanic activity at Ogasawara Islands (Bonin Islands) Nishinoshima volcano has continued an active volcanic activity for about 2 years.
But the volcanic activity was declining finally, and the eruptive activity wasn't confirmed any more by an investigation after 22 December 2015.
The Japan Coast Guard has been carrying out observation of Nishinoshima volcano in cooperation with the Tokyo Institute of Technology since the volcanic activity’s restart was confirmed.
A detailed report is done about a change in the activity style of the eruptive after the flank eruption of volcanic cone on 7 July, 2015.
There was a lava flow which reaches an east-south side coastline from the northeast side of the formed volcanic cone on the south side of Nishinoshima from after May, 2015 to around July.
The volcanic activity of this period has been eruption successively.
And , the summit eruption became dormant at early morning on 6 July, 2015 , Japan coast Guard survey vessel was investigating.
And flank eruption has begun from the volcanic cone’s north side around 10:50 about 4 hours later.
Next day, The eruption resumed from the summit crater of volcanic cone at early morning on 7 July, 2015.
The two big craters were formed to the top of the volcanic cone as a result of flank eruption on July 6-7.
It's the activity style in intermittent eruption of the strombolian type from the activity that strombolian eruption is continued more continuously, it changed.
There were no expansion of land area for lava flow like before on July 2015, because the volume of lava decreased.
The vulcanian eruption was a sound with eruption and infrasonic wave in airplane on 17 November, 2015.
Eruptive activity wasn't admitted in December, 2015, and the temperature in the crater also fell to the surrounding temperature level.
There are no reports of the eruptive activity current as of January, 2016.