KIRISHIMA VOLCANO, Kyushu
(1,700 m, 31o55'51"N, 130o5150"E)
(Jan 17, 2004)
New fumarole pits were found at the Ohachi Crater of Kirishima Volcano by
Dr. Tetsuo Kobayashi, Kagoshima University, on 13 December. Real-time camera
of JMA also showed steam rising above the crater rim. JMA issued the Observation
Report on Kirishima Volcano on 14 December 2003. New two pits were formed
in the middle part of southern inner-wall of the Ohachi Crater. Steam was
rising up to about 100 m. Pebbles of 2-3 cm across and mud were scattered
within about 10m from these pits.
JMA issued the Volcanic Advisory on this volcano on 16 December, as the
possibility of small eruption had risen, judging from a high level of seismic
and thermal activity.
Cities and towns around this volcano announced forbiddance for tourists
to approach the Ohachi Crater on 17 December 2003.
Seismic activity increased in 13 December, being peaked in the middle December,
and declined with time. However, relatively high seismic activity has continued
as of the middle January of 2004.
According to Tokyo Institute of Techonology, chemistry of water-soluble
component of the ash, which was attached on pebbles scattered around the
fumarole pit, suggested contribution of magmatic gas. Dr. Koichiro Watanabe,
Kyushu University, investigated petrologically the ash and he concluded no
juvenile materials among the ash particles.
(11/16/99)
Volcanic Advisory on Kirishima Volcano was issued on 10 November by JMA.
Volcanic earthquake events increased since 6 November. Issuing the volcanic
advisory of this volcano is the first since 27 August 1995. The daily numbers
of volcanic earthquake events are;
5 Nov. = 0
6 Nov. =12
7 Nov. = 16
8 Nov. = 40
9 Nov. = 81
10 Nov. =192
11 Nov. = 128
12 Nov. = 69
13 Nov. = 86
14 Nov. = 11
15 Nov. = 31
(detected at the JMA-A site, 1.7 km SW of Shinmoedake)
No volcanic tremor was observed.
[BACKGROUND]
Kirishima is a volcanic group of more than 20 andesitic small stratocones
(Takachihonomine, Nakadake, Ohatayama, Karakunidake, Tairoike, Ohachi, Shinmoedake,
etc), occupying an area of about 20x30 km elongated in the NW-SE direction.
It developed in the southern rim of the Kakuto Caldera of 300 ka. Relatively
large craters characterize the volcano. Ebino highland in the northern part
and the SW slope are active geothermal regions. Sulfur fumaroles are evident
in N-slope of the Karakunidake in N-part of the volcano. Historic eruptions
recorded since 742 occurred mre than 60 times mainly within the craters of
Ohachi and Shinmoedake. Relatively large eruptions occurred in 788, 1235,
1716-17 and 1768. A small phreatic eruption took place at Shinmoedake in 1991
(below). Geophysical monitoring is maintained mainly by Earthquake Research
Institute (ERI), University of Tokyo, and Japan Meteorological Agency (JMA).
Steam from Shinmoedake, Kirishima Volcano, from NW taken in 1991. Nakadake
is the adjacent cone with a flat top, and the background is Ohachi (crater),
Takachiho-no-mine (the highest) and Futatsuishi. Courtesy of T. Kagiyama,
ERI.
Link to: Kagiyama's
Japanese home page
Information contact: JMA-Fukuoka; jma16@poplar.ocn.ne.jp, Volcano
Research Center, ERI, U-Tokyo; nakada@eri.u-tokyo.ac.jp, kagiyama@eri.u-tokyo.ac.jp
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