华北块体内地震与形变场和重力场变化  

EARTHQUAKES IN NORTH CHINA BLOCK AND EVOLUTION OF DEFORMATION FIELD AND GRAVITY FIELD

作　　者：刘善华[1] 

机构地区：[1]中国地震应急搜救中心,北京100049

出　　处：《东北地震研究》2006年第2期1-10,共10页Seismological Research of Northeast China

摘　　要：分析总结了唐山、大同和张北三次强震前形变场和重力场变化特征,即震前形变场和重力场均表现为正异常。结合人工地震深部探测结果研究表明,华北块体内强震具有一致的孕震机理,可能都与地幔热物质上涌有关;2004年1月滦县ML5.0地震震前形变场出现上升,但重力场出现了下降的变化特征,说明震前孕震区未出现地幔热物质的上涌。这可能是华北块体内强震与中等地震在孕震机理上的主要区别,对板内地震的预测有重要参考意义。In this paper, the character of the evolution of deformation field and the evolution of gravity field before three macroseisrns in Tangshan, Datong and Zhangbei is studied and summarized. Both the deformation field and gravity field show positive anomaly before earthquake. Result of artificial earthquake prospecting are applied, the study shows that mechanism of three macroseism occurring is homology in North China, It is possible that mechanism of three macroseism occurring are all related to the rising of hot mantle material.Deformation field occur ascent variations before Luanxian ML5.0 earthquake on January, 2004. But gravity field occur descent variations before earthquake. This explains that the rising of hot mantle material is not occurred before the earthquake in seismogenic zone. This is the main differentiation of the macroseism and moderate earthquake on genesis of intraplate earthquake.This has the importance reference meaning to anticipation of intraplate earthquake.

关 键 词：华北块体 强震 滦县ML5.0地震 形变场 重力场 地幔隆起 孕震体膨胀 

分 类 号：P315.7[天文地球—地震学]