南海北部海底地热测量的数据处理方法

为了解南海北部地热分布特征，使用EWING型海底地热探针在3个区域进行海底地热测量，利用TK04型热导率仪测量采自3个区域的沉积物样品的热导率，并对相关数据进行一系列校正处理，获得3个代表性站位HD343、HS82、HX129的热流密度。数据分析表明:对于EWING型探针需要对原始温度记录进行偏移量校正和平衡温度计算；不同自容式温度传感器(MTL)间的相对温度偏移量是基本固定的，取决于记录器本身的性质，与测站位置无关；插入海底后，EWING型探针记录的温度随时间的变化取决于摩擦生热的大小，如果摩擦引起的温度变化小于环境温度，温度将随时间缓慢上升，否则随时间缓慢降低；室内测量的热导率经过温度和压力校正后，一般降低4％～5％；3个站位的地温梯度分别是81 ℃/km、109 ℃/km、94 ℃/km，热导率分别为0.979 W/(m·K)、0.785 W/(m·K)、0.886 W/(m·K)，热流密度分别为79 mW/m²、86 mW/m²、83 mW/m²。

Data Processing Methods of Marine Geothermal Measurement on the Northern Margin of the South China Sea

To investigate the geothermal distribution of the northern margin of the South China Sea,EWING-type heat flow probe was employed to measure the temperature gradient of the marine sediments in three regions,and sediment samples were cored for thermal conductivity with a thermal conductivity meter TK04.After a series of detailed data processing,the heat flow data of three representative sites HD343,HS82 and HX129 were obtained.The analyses show that it is necessary for EWING-type heat flow probe to correct the original temperature data for logger offsets and compute equilibrium temperatures for each logger.The relative temperature offset between two MTLs is thought to be a fixed value,which depends mostly on their own nature,not changing from site to site.After penetration,how the recorded temperature changes with time depends on the friction heat(amount) produced by penetration,if the temperature raised by friction heating is higher than ambient temperature,the temperature will drop slowly to the ambient temperature,otherwise,the temperature will raise slowly to the ambient temperature.After in-situ temperature and pressure are corrected,the thermal conductivities will decrease about 4% to 5%.The thermal gradients for the three sites are 81,109 and 94 ℃/km respectively,and thermal conductivities are 0.979,0.785 and 0.886 W/(m·K)respectively,and heat flow values are 79,86 and 83 mW/m~(2) respectively.