General study on the eruption at Shinmoedake volcano, Kirishima, in 2011

2011年雾岛新茂岳火山喷发综合研究

• 批准号: 22900001
• 负责人: NAKADA Setsuya
• 金额: --
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 财政年份: 2010
• 资助国家: 日本
• 起止时间: 2010 至 2011
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-22900001/
• 关键词: 地震現象; 火山現象; 地殻変動・海底変動; 地磁気; 重力; 観測手法; 新燃岳; マグマ噴火; プリニー式噴火; ブルカノ式噴火; 噴火シナリオ; 地殻変動

A magmatic eruption event took place at Shinmoedake (Kirishima) Volcano in January 2011, leaving about 300 years of hiatus. Three subplinian explosions occurred on 26 and 27 January, which were followed by 4-day accumulation of lava at the summit crater. Vulcanican explosions were repeated from February to April, and a series of eruptions ended with phreatic explosions which occurred in June and September 2011. This eruption event was preceded by both phreatic explosions in 2008 and 2010 and elevated seismic activity in the regions surrounding Kirishima. GPS observation indicated that significant swelling of the magma chamber which located about 6 km NW of the Shinmoedake crater had continued since the end of 2009. Deflation of the magma chamber accompanied clearly subplinian explosions and the lava accumulation in the crater. The strain-meter observation showed small increases in pressure several tens of minutes prior to the subplinian explosions. Seismic array-observation during a se … More ries of vulcanian explosions showed that volcanic tremors occurred beneath the summit crater and between it and the magma chamber, supporting magma's migration from the magma chamber to the crater. The latter was confirmed by the absolute gravity measurement at the place just above the magma chamber. Inflation of the summit area, ncrease in the shallow earthquakes and decrease in the volcanic gas emitted from the crater were observed prior to the vulcanian explosions, strongly implying sealing of the conduit top preceding the explosions. It is considered that magma mixing occurred just before the eruption event because the products of the earliest stage consisted of two magmas with different compositions. The total volume of magma erupted in this event is estimated about 25 million m3, which is about 1/3 volume of the eruption 300 years ago.During this study, we tried two times to make the eruption scenario in which sequences of eruptions are indicated, based on records of eruptions of this volcano 300 years ago and of analogous volcanoes in and outside Japan. No significant mudflows occurred in this eruption event. It is considered that the reason is that the eruption products were mainly of pumice which has high permeability of rain water. Inflation of magma chamber resumed soon after the eruptions in January 2011 and continued by the end of 2011, reaching the same level before the eruption event. It almost stopped in the beginning of 2012, suggesting a halt of the magma supply from depth. Less

2011年1月，新竹（雾岛）火山发生了岩浆喷发事件，造成了大约300年的间歇。1月26日和27日发生了三次地下爆炸，随后在山顶火山口积聚了4天的熔岩。从2月到4月，火山爆发反复发生，2011年6月和9月，一系列火山爆发以潜水式爆炸结束。在这次喷发事件之前，2008年和2010年的两次潜水爆炸以及雾岛周围地区的地震活动加剧。GPS观测显示，位于Shinmoedake陨石坑西北约6公里处的岩浆库自2009年底以来一直在持续显著膨胀。岩浆房的收缩伴随着明显的俯冲爆炸和火山口的熔岩堆积。应变计观测显示，在次平面爆炸前几十分钟，压力有小幅上升。更多的火山爆发表明，火山震动发生在山顶火山口下方及其与岩浆库之间，支持岩浆从岩浆库向火山口的迁移。后者是由岩浆房上方的绝对重力测量证实的。火山喷发前观察到峰顶区域的膨胀、浅层地震的增加和火山口喷出的火山气体的减少，这强烈暗示了火山喷发前管道顶部的密封。由于最早阶段的产物由两种不同成分的岩浆组成，因此认为岩浆混合发生在喷发事件发生之前。这次喷发的岩浆总量估计约为2500万立方米，约为300年前那次喷发的1/3。在本研究中，我们根据300年前这座火山的喷发记录以及日本国内外类似火山的喷发记录，两次尝试制作喷发场景，其中显示了喷发顺序。这次喷发没有发生明显的泥石流。认为喷发产物主要为浮石，具有较高的雨水渗透性。2011年1月火山喷发后，岩浆库的膨胀很快恢复，并持续到2011年底，达到喷发前的水平。2012年初，它几乎停止了喷发，这表明岩浆供应已经停止。少

项目成果

霧島新燃岳2011年1月26日噴火前後の地殻変動

2011年1月26日雾岛新茂岳喷发前后的地壳运动

• 发表时间: 2011
• 作者: 中尾茂・森田裕一・後藤和彦;八木原寛・平野舟一郎;ほか
• 通讯作者: ほか

火山噴火予測における測量データの重要性

调查数据在预测火山喷发中的重要性

• 发表时间: 2012
• 期刊: 先端測量技術
• 作者: 中田節也・森田裕一・清水洋・宮町宏樹・中道治久・他;中田節也
• 通讯作者: 中田節也

新燃岳・享保噴火における被災状況について

关于新茂岳/巨峰喷发造成的损失

• 发表时间: 2011
• 作者: Fujii;Y.;K. Satake;S. Sakai;M. Shinohara;and T. Kanazawa;岡崎康浩;筒井正明・小林哲夫
• 通讯作者: 筒井正明・小林哲夫

MT連続観測による霧島硫黄山北の比抵抗変化

通过连续 MT 观测观察雾岛 Ioyama 北部电阻率的变化

• 发表时间: 2011
• 作者: 鈴木由希・中田節也・他;板倉陽子;相澤広記・上嶋誠・橋本武志・神田径・他
• 通讯作者: 相澤広記・上嶋誠・橋本武志・神田径・他

新燃岳の噴火シナリオ(2)

新茂岳喷发情景（2）

• 发表时间: 2011
• 作者: Shinohara;M.;T. Yamada;K. Nakahigashi;S. Sakai;K. Mochizuki;K. Uehira;Y. Ito;R. Azuma;Y. Kaiho;T. No;H. Shiobara;R. Hino;Y. Murai;H. Yakiwara;T. Sato;Y. Machida;T. Shinbo;T. Isse;H. Miyamachi;K Obana;N. Takahashi;S. Kodaira;Y. Kaned;植木貞人・大久保修平・大島弘光・他;中田節也
• 通讯作者: 中田節也