Integrating the electrical resistivity tomography and the microtremor exploration technology to explore the spatial distribution of the mud reservoir and the channel of the Gunshuiping mud volcano

The rapid sedimentation of the seafloor in southwestern Taiwan in early period created the sediments which are not fully compacted and cemented. With the developing geological process, a well-developed mud diapir was formed. Linear structures such as faults or fissures were exposed on the earth’s surface to form mud volcanoes of different scales. Our study area is located at the Gunshuiping mud volcano in Yanchao District and Qiaotou District, Kaohsiung City. It is adjacent to the Qishan Fault and spans the Chegualin Fault, which is the extension of the Longchuan Fault. According to the geological map published by Central Geological Survey, MOEA, the stratum from top to down in this area can be divided into recent alluvial formation, terrace deposits formation, Qiding formation, Gutingkeng formation, etc. The mud eruption of the Gunshuiping mud volcano was chemically analyzed and the result showed that it is the product of the Gutingkeng formation. This project will use the Electrical Resistivity Tomography (ERT) to construct a complete subsurface stratum distribution map and the structure of the mud volcano, and combine the micro-tremor site exploration technology to analyze the underground structure of mud volcano. The ERT method can observe the mud reservoir content and mud channel structure under the surface and analyze the trend of mud flow, while the micro-tremor site exploration technology can observe the underground velocity structure caused by mud volcanic activity, and explore its mud accumulation thickness, fissure distribution and potential Eruption range. Therefore, the two methods can be seen as complementary and mutually corroborate each other's information. In the future, this method can be used to make plan and take precaution in advance for the activity level and the influence area of Gunshuiping mud volcanoes or other geologically sensitive area.