南海海底沉积物声学物理参数测定的温度和时间优化研究  

Optimization of temperature and time of acoustic physics parameters of seafloor sediment in the South China Sea

作　　者：罗云[1,2] 侯正瑜 田雨杭[1,2] 许安涛 陈忠 LUO Yun;HOU Zhengyu;TIAN Yuhang;XU Antao;CHEN Zhong(CAS Key Laboratory of Ocean and Marginal Sea Geology,South China Sea Institute of Oceanology,Guangzhou 510301,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院边缘海与大洋地质重点实验室(南海海洋研究所),广东广州510301 [2]中国科学院大学,北京100049

出　　处：《热带海洋学报》2018年第4期81-88,共8页Journal of Tropical Oceanography

基　　金：国家自然科学基金(41376057;41676056);国家科技支撑计划(2014BAB14B01)~~

摘　　要：海洋沉积物含水率、密度和孔隙度等物理参数是沉积物声学特性研究中的重要指标。由于南海沉积物类型多样、成分复杂,特别是深海沉积物样品珍贵,需精确测定沉积物声学及物理参数并无损害地保持沉积物化学性质。文章以黏土、粉砂和砂三种典型海底沉积物为研究对象,使用环刀法和烘干法,在不同温度条件下(60℃、80℃、100℃和120℃)测定和分析了这三种沉积物的含水率、密度、孔隙度随烘干时间的变化趋势及特征,并进行了回归分析和综合研究。结果表明:1)对同类型沉积物,温度越高,完全失去孔隙水的时间越短,且失水过程具有阶段性;2)同一温度下,三种典型沉积物完全失去孔隙水的时间为t_砂<t_(粉砂)<t_(黏土),且不同时间段,失去孔隙水的速率差异较大,这主要与沉积物的颗粒大小、颗粒间的间隙大小以及烘干后期沉积物中所含的水分均已大部分流失有关;3)建议声学沉积物样品的烘干温度以80℃左右为宜,并给出三种沉积物完全烘干的参考时长和临界时间;4)在温度为80℃时,将临界时间处的物理参数带入经验方程进行声速预报是可行的。Physical parameters such as water content,density and porosity of marine sediments are important for studying acoustic characteristics of sediments.Due to the complex and variety of the marine sediments in the South China Sea and precious deep-sea sediment samples,it is necessary to accurately determine the physical parameters of these sediment samples and make sure no damage to their chemical properties.However,the current measuring methods cannot meet the demands.In this study,we determined and analyzed the changing trends and characteristics of the water content,density,porosity of the clay,silt,and sand in three typical sediments with the drying time under different temperature(60,80,100,and 120℃)by using circular knives method and dryer method.The results are as follows.1)The higher the temperature,the shorter the time of the total loss of pore water,and the periodic characteristics of the water loss process for the same type of sediment.2)The times of typical sediments completely lose the pore water are in the order of tsand<tsilt<tclay;and at different time periods,the rate of pore water loss is quite different,which is mainly related to the particle size,the gap between particles and the loss of moisture contained in sediments in the later stage of drying.3)The drying temperature of 80℃is advisable,if the sediments is also needed for further comprehensive utilization and analysis,and the reference time and critical time are calculated for the complete drying of the three sediments.4)Physics parameter of the critical time generation into the experience equation for velocity prediction is feasible at 80℃.

关 键 词：南海 沉积物 物理参数 温度 时间 

分 类 号：P736.211[天文地球—海洋地质] P733.2[天文地球—海洋科学]