Eruption of Kuju Volcano
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Kuju volcano viewed from east. Far away in the skyline, the Unzen volcano can be seen.
Kuju Volcano Erupted again.
On 18 Dec 1995, it is reported Kuju volcano erupted again. Please wait for new informations!
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Kuju volcano
Kyushu, Japan
33.08N, 131.25E; summit elevation 1788 m
Kuju volcano is located in the NE of Aso Caldera. Kuju volcano consists of many stratovolcanoes and lava domes.
Location of Kuju volcano
Eruptive History
Kuju volcano is active through Holocene and have several historical eruption records. The historical eruption records do not suggest magmatic eruptions but phreatic or hydrothermal eruptions. Most youngest magmatic eruption, estimated from geological record is about 1.7ka erupted Kurodake lava dome and pyroclasticflow in the eastern part of Kuju.
Historical Records
- 1738: phreatic eruption? molten sulfur effusion?
- 1675: molten sulfur effusion?
- 1662: Ash emission?
In the central part of Kuju volcano, there is active fumarole called Io-san. At least for 500 years, there was a sulfur mine at Io-san. There are many hot springs and geothermal fields around the Kuju volcano, and two geothermal powerplants are working.
October1995 Eruption
Eruption was began at about 18:00 October 11, 1995 in the northern flank of Hossyo dome, the central part of Kuju volcano without remarkable seismicity.
About 400m long fissure running west to east effused ash and small lahar. Ash fall was observed in Kumamoto city, 60km NW of the volcano. But activity was decreased soon and in October 12, there was only white vapor fumarole about 400m high (JMA reports). The fissure formed several sub-fissures and craters. They are named a1, a2, a3 craters, and b, c, d, e sub-fissures (Nakata and Watanabe, Data for Coordinating Committee for Eruption Prediction).
Photo Gallery of Kuju Eruption
Eruption Points, Northern View
Leftside fumarole is Io-san. Right most fumarole is from a1 crater.
Fissures viewed from south
From the righthand, a3 (behind the ridge), e, d, c, b fissures successively.
Fissures viewed from northeast
From lefthand, a3, e, d, c, b, a2, a1. We can see fumarole of Io-san in the foreground.
The Aerial View of Fissures
From the down left, a1 with white fumarole, a2, b fissure, c fissure, d and e. In the left side of the e crater, there is a3 crater.
a2 crater
Diameter is about 30m.
Cross section of the deposits
Cross section of the fall deposits near b fissure.
Other Site for Kuju Eruption
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Last modified 97.4.6
This page is maintained by Kawanabe "yagi" Yoshihisa.
Location of Kuju volcano
Eruption Points, Northern View
Fissures viewed from south
Fissures viewed from northeast
The Aerial View of Fissures
a2 crater
Cross section of the deposits