摘要
利用调和分析以及小波分解与重构等信息挖掘方法,对1749年来的太阳黑子月统计数据,1920年来全球地震目录MS6.0以上地震年统计数据,1950年来华北地区ML4.7级以上地震目录,地球自转速率1832—1997年的年统计数据及1962年来的月统计数据,进行对比分析,研究发现:(1)在太阳活动处于强烈期时,地球大震处于高发期且略滞后2~5年,而此时地球自转速率处于减速期,其时间跨度约22年。(2)对于太阳黑子数11年的周期变化,在正常变化下如果处于低值期,期间地球地震活动也将增加,但地震发震时间滞后1~2年。考虑太阳黑子与日冕活动有继承性及延迟性的特点,我们认为引起11年左右的地震群活动可能不是直接受太阳黑子的影响,而是受太阳日冕活动影响。因为日冕抛射物在太阳黑子磁场弱化1年左右时爆发,使得太阳外层扁率增加并经常抛射一次性质量高达1013 kg的物质,从而导致地球自转速率因摄动效应而发生同步性减慢,以及地球地震活动增强。
In this article the data mining methods of harmonic FFT and wavelet analysis are implemented to analyze the relation between these data sets: monthly sunspots recorded from 1749; global earthquakes; Ms6 from 1920; north China earthquakes;ML4.7 from 1950;annual LOD of Earth recorded from 1832 to 1997 and monthly LOD of Earth from 1962. Two main conclusions are given as: (1)during high Sun activity time, Earthquakes activities also are in a high level albeit which occurrence postponed for 2-5 years. At that time, LOD of Earth is at a low speed. This time span is about 22 years. (2)in the normal evolvement of sunspots cycle of 11 years, during the low sunspots numbers Earthquakes will be increased albeit which occurrence postponed for 1-2 years. Considering the characteristic of their occurrence subsequence and postponing between the sunspots and CME activities, we think of the 11 years change of Earthquakes activities is indirectly due to impact of the sunspots, and yet influenced by the CME. Its reason comes from the fact of the CME occurrence rate rise sharply after just 1-2 years as the sunspots magnetism descend. Strong CME will increase Sun apparent oblateness, and continually throw out a huge matter of up tol013kg one time, which result in the synchronous change of LOD of Earth as the celestial perturbation and enhancement of earthquakes activities.
出处
《华北地震科学》
2013年第1期1-7,共7页
North China Earthquake Sciences
基金
中国地震局震源深度跟踪小组专项(82109)
2013年测震青年专项(20130202)
天津市地震局青年基金课题(12103)