研究期間:10301~10312;KEYWORDS: Gas-Hydrate; Sidescan Sonar; Sub-bottom Profiler; Multibeam Abstract This proposal belongs to a 4-years project "Investigation of Gas Hydrate Resource Potential: High-resolution Sonar Surveys" of the Central Geological Survey from 2012 to 2015. The high-resolution deep-tow sonar will be used for the gas hydrate study. The purpose is to understand the characteristic features of the seabed and to identify the distribution of cold seeps, mud volcanoes, mud diapirs, pockmarks. We will study the characteristics of the sedimentary strata and analyze the possible gas migration conduits or paths. Meanwhile, we will study the shallow features of seabed for gas hydrate reservoir system. We will gradually compile a high-resolution bathymetry off SW Taiwan. We will also explore the formation of shallow resistivity characteristics, to understand the near seabed distribution of gas hydrate. To do this four-years project, the high-resolution sonar (including sub-bottom profiler and sidescan sonar), multi-beam echo sounder surveys and marine resistivity measurements will be conducted. To 2013 year, there are deep-tow sonar surveys conducted in the area of the Yuan-An Ridge and the Good-Weather Ridge in the last five years. The data show a variety of different topography and tectonic structures in this region. The results indicate a prominent pockmark area exists around an anticline structure to the southeast of the Yuan-An Ridge. Several pingo structures are also distributed. The high potential storage of the gas hydrate is inferred in this area. Until now, the project "Investigation of Gas Hydrate Resource Potential: High-resolution Sonar Surveys" only be carried out in the passive margin off SW Taiwan. But, this project will be based on the results of the existing data from the gas hydrate studies off SW Taiwan. We will keep on conducting high-resolution sonar and multi-beam echo sounder surveys in order to provide a better understanding for the potential distribution of gas hydrate resources off SW Taiwan. The targets of this year work consist of: 1. To conduct deep-towed sub-bottom profiler and sidescan sonar surveys in around the Pointer Ridge. 2. To conduct multi-beam echo sounder surveys in the continental shelf and slope area of the west side of Deformation Front.