中朝边境天池破火山口湖底地形多波束测深探测

摘要

为调查天池破火山口湖的基本参数和湖底地形特征,研究破火山口的内部构造、破火山口的组合样式和垮塌堆积分布,本文采用多波束测深方法,对天池湖底地形进行了探测.探测结果显示:天池最大水深值为373.2m,天池水域边界实测周长为13.44km,天池湖水面面积9.4km2,天池总蓄水量约为19.88×108m3.天池周边分布4个温泉,温度为7 ～47℃.根据湖底地形推断,现今的天池破火山口形成于千年大喷发.其后,在天池西侧形成一个喷火口,东侧形成一个熔岩丘.天池湖底存在5个较大的破火山口内壁垮塌堆积区,但在湖底未见熔岩流.天池边缘出露的温泉点对应环状断裂,同时反映深部存在岩浆体.%In order to investigate the basic parameters and lakebed topographic features of the Tianchi caldera lake and study its internal structure,combination pattern and distribution of collapse depositions,the lakebed topography has been explored through the multibeam sounding system.The maximum depth,waters boundary circumference,area and total storage of the Tianchi Lake are 373.2m and 13.44km,9.4km2 and 19.88 × 108m3,respectively.There are four hot springs around the Tianchi Lake with temperatures of 7 ～47℃.By deduction of the lakebed topography,the present caldera was formed in millennium eruption,and then a small vent in western Tianchi Lake and a lava dome in eastern emerged.There are 5 larger collapsed deposition areas of inner caldera wall,but no lava flow on the Tianchi lakebed.The spots of hot springs around the Tianchi Lake match with its ring fractures,which reflects a deep magmatic body.