利用瑞利激光雷达和无线电探空仪观测数据对武汉上空重力波特性的研究

本文利用武汉大学的瑞利激光雷达的瑞利散射回波数据(30～65 km)来研究武汉地区上空(305°N，1144°E)〖JP〗重力波的活动规律和统计特性.通过对2003年12月到2005年3月观测的200 h数据反演的密度进行处理分析，得到了重力波的一些个例特征，并提取垂直波长为2 km以上的重力波进行统计分析.结果表明，最可几的垂直波长是3～4 km和17～20 km，重力波振幅的月平均值在冬季有较大值，夏季值较小.与武汉2004年无线电探空仪的密度扰动提取到的重力波做比较，发现与瑞利激光雷达得到的重力波振幅的月平均值有很强的相关性，也是冬季值比较大，夏季值比较小.通过无线电探空仪的风场数据，本文还得到了急流的季节变化规律、最大风剪切年变化规律，发现急流和最大风剪切与激光雷达的重力波统计结果有很强的相关性.

Calibration of seismic reflectors at the Chinese Continental Scientific Drilling site

Three-dimensional seismic survey has been carried out for the Chinese Continental Scientific Drilling(CCSD) project,showing that many reflectors occurr in the upper crust beneath the drilling area.Calibration of the reflectors by using cores and well-logging data can significantly enhance reliability of their interpretation.As 2-D seismic reflectors might be related to direction of the 2-D lines,3-D surveys present reflectors unrelated to the line direction,therefore provide more reliable reflectors for the calibration.Only after obtaining a correct velocity model that gives perfect fit between the 3-D seismic profile and the synthetic seismic trace derived from well-logging data,the calibration of reflectors can become meaningful.Simple comparison of the core log,well-logging curves and reflection sections is not enough for the calibration,because non-linear time-depth conversion and deviation of the well are not considered in the procedure.The calibration should proceed from one reflector to another considering both the non-linear time-depth conversion and deviation of the well.The calibration at the CCSD site via the main hole finds many causes that can generate reflectors in the crystallized crust.They include mainly three types as follows:(a) ductile-shearing-origin reflectors;(b) intrusion-or-metamorphic-lens origin;and(c) origins related to inhomogeneity of country rocks,such as gneisses.