地震学报（英文版）2004，Vol.17Issue(z1)：85-93,9.
Geomagnetic diurnal-variation anomalies and their relation to strong earthquakes
Geomagnetic diurnal-variation anomalies and their relation to strong earthquakes
摘要
Abstract
The diurnal-variation anomalies of the vertical-component in geomagnetic field are mainly the changes of phaseand amplitude before strong earthquakes. On the basis of data recorded by the network of geomagnetic observatories in China for many years, the anomalous features of appearance time of the minima of diurnal variations (i.e,low-point time) of the geomagnetic vertical components and the variation of their spatial distribution (i.e, phenomena of low-point displacement) have been studied before over 30 strong earthquakes with Ms≥6.6 such asKunlunshan Ms=8.1 earthquake on November 14, 2001; Bachu-Jashi Ms=6.8 earthquake on February 24, 2003;Xiaojin Ms=6.6 earthquake on September 22, 1989, etc. There are good relations between such rare phenomena ofgeomagnetic anomalies and the occurrence of earthquakes. It has been found that most earthquakes occur in thevicinity of the boundary line of sudden change of the low-point displacement and generally within four days beforeand after the 27th or 41st day counting from the day of appearance of the anomaly. In addition, the anomalies ofdiurnal-variation amplitude near the epicentral area have been also studied before Kunlunshan Ms=8.1 earthquakeand Bachu-Jiashi Ms=6.8 earthquake.关键词
geomagnetic diurnal-variation anomalies/geomagnetic low-point displacement/diurnal-variation amplitude/strong earthquakeKey words
geomagnetic diurnal-variation anomalies/geomagnetic low-point displacement/diurnal-variation amplitude/strong earthquake分类
天文与地球科学引用本文复制引用
丁鉴海,刘杰,余素荣,肖武军..Geomagnetic diurnal-variation anomalies and their relation to strong earthquakes[J].地震学报（英文版）,2004,17(z1):85-93,9.基金项目
National Science Technology Tackle Key Project during the Tenth Five-year Plan (2001BA601B01-05-04) （2001BA601B01-05-04）
