东北深震的孕震三步曲  

Three stages of deep earthquake gestation in Northeast China

作　　者：汤懋苍[1] 廖留峰[1,2] 郭维栋[3] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所,甘肃省干旱气候变化与减灾重点实验室,兰州730000 [2]中国科学院研究生院,北京100049 [3]南京大学大气科学学院,南京210093

出　　处：《地球物理学进展》2011年第6期1931-1937,共7页Progress in Geophysics

基　　金：国家973项目(编号:2008CB425704);国家自然科学基金面上项目(课题号:40975049)共同赞助

摘　　要：中国东北地区存在一条震源深度达600公里深震带,频发深源地震,本文通过分析1973年9月27日东北7.7级深震发震前0.5～1年的月际变温场和降水距平场的变化特征,得出中国东北区域深震的孕震过程与我国浅震一样也存在孕震三步曲;近30年9次深震的统计分析表明:东北深震的整个孕震时间以及各步之间的孕震时间均与我国浅震的孕震时间基本相同,唯地壳被压缩的时间东北深震比我国浅震要短一倍左右.东北深震孕震第一步中"热旱区"外围相对多雨带的平均半径与未来震级之间的相关系数达到0.96,用环带半径可估计出未来的震级,根据深震孕震三步曲的各步时间可估算出发震时间.东北深震与相匹浅震组成的"拍地热涡"亦可引发强大多雨区.表明深震肇因与浅震一样均来自壳幔层以下,其差别仅在于岩石圈的脆性层深度不同.A deep focus earthquake zone as deep as 600 kilometers exists in Northeast China and deep earthquakes happen frequently here. By analyzing feature of monthly temperature variation fields and precipitation anomaly percentage about 0. 5- 1 a before the deep earthquake measuring 7. 7 magnitude on the Richter scale happened in Northeast China on 27th September, 1973, a conclusion is made that ＂the three stages for earthquake gestation＂ which exists in the procedure of deep earthquakes in Northeast China, is similar to shallow earthquakes of China. And according to statistical data and analytic results of deep earthquakes, it＇s made clear that the whole time of deep earthquakes in Northeast China and the time between each step are basically the same to shallow earthquakes of our country, except the time of crust compressed is one time shorter than shallow earthquakes. Besides, a rain-belt around a ＂hot drought region＂ which exist in the first step. The average radius of this rain-belt has a strong link with the coming deep earthquakes~ magnitude. And the related coefficient is up to 9. 6. Therefore, magnitude should be estimated, and happening time of the earthquake also can be estimated according to the time of each step in earthquake gestation. The ＂beat geothermal vortex ＂ which is made up of deep earthquakes in Northeast and its match shallow seism also can generate a heavy rainfall area, It shows that like shallow earthquakes, causes of deep earthquakes come from the under crust mantle layer. The only difference is the depth of the lithosphere＇s friable layer.

关 键 词：东北深震 月际变温场 降水距平百分率 孕震三步曲 拍地热涡 

分 类 号：P315[天文地球—地震学]