A resistivity cross-section of Usu volcano, Hokkaido, Japan, by audiomagnetotelluric soundings
A resistivity cross-section of Usu volcano, Hokkaido, Japan, by audiomagnetotelluric soundings
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日本北海道有珠火山的电阻率横截面，采用音频大地电磁探测
DOI：
10.1186/bf03352120
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
T. Doi
中科院分区：
文献类型：
--
作者：
Yasuo Ogawa;N. Matsushima;H. Oshima;S. Takakura;M. Utsugi;K. Hirano;M. Igarashi;T. Doi
我们收集了日本北海道有珠火山的音频大地电磁 (AMT) 数据，该火山于 1977 年喷发，目前仍然活跃。我们获得了 17 个垂直于区域构造走向的地点的剖面图，该走向穿过了 1977 年的隐穹顶——有珠新山。张量分解数据通过二维反演来解释。在火山口边缘之外，电阻率结构简单。电阻索玛熔岩下面是导电基底，这意味着第三纪或第四纪岩石发生了蚀变。在火山口内，有两个电阻体被垂直导体一分为二，对应于位于隆起底部的有珠新山断层。 1985 年的 AMT 探测中没有检测到垂直导体。垂直导体发展的可能原因之一是冷水从地表供应到以蒸汽为主的断裂带。其中一个电阻体位于有珠新山下方，暗示着 1977 年隆起的侵入岩浆体。
We collected audio-magnetotelluric (AMT) data across Usu volcano, Hokkaido, Japan, which erupted in 1977 and is still active. We had a profile of 17 sites perpendicular to the regional tectonic strike, which crossed the 1977 cryptodome, Usu-Shinzan. Tensor-decomposed data were interpreted by a two-dimensional inversion. Outside the crater rim, the resistivity structure is simple. The resistive somma lava is underlain by a conductive substratum, implying altered Tertiary or Quaternary rocks. In the crater, there are two resistive bodies bisected by a vertical conductor, which corresponds to Usu-Shinzan fault, located at the foot of the uplift. The vertical conductor was not detected in the AMT sounding in 1985. One of the possible causes of the development of the vertical conductor is a cold water supply from the surface into the vapor dominant fracture zone. One of the resistive bodies is located beneath Usu-Shinzan and implies an intrusive magma body which caused the 1977 uplift.