广西近海灾害地质因素及声学反射特征

Neritic hazardous geology and its characteristic acoustic reflection in offshore of Guangxi

利用高分辨率地球物理资料及相关历史资料,对北部湾北部的广西近海灾害地质因素进行了地质地球物理解译,识别出海底沙波、海底沙脊、塌陷洼地、冲刷沟槽、浅层气、残积砂体、地层间断、埋藏丘、埋藏古河道等多种灾害地质因素.根据它们出现的频率、规模及声学特征可知:浅层气和埋藏古河道是广西近海最为发育的灾害地质因素,其对海洋工程的施工与建设有较大的危害性.

The author attempt to provide the geological and geophysical interpretation of the neritic hazardous geology on the basis of the high-resolution geophysical data and historical data from the bay and identify a number of neritic hazardous geology,such as submarine sand wave and sand ridge,collapsed depressions,washed groove,shallow gas,residual sand body,stratigraphic hiatus,buried hill,buried ancient river,etc. According to the charac-teristics of acoustic reflection and also the scale and frequency that turn up on the sub-bottom profiles and side scan sonar image. The authors conclude that the shallow gas and buried ancient river are the most common hazardous geology in offshore of Guangxi as they potentially jeopardize the marine constructions.