2020年唐山古冶5.1级地震前流体固体潮参数时空变化研究

Study on Temporal and Spatial Variation of Fluid Solid Tide Parameters before the Tangshan Guye M_(S)5.1 Earthquake in 2020

以2020-07-12唐山古冶5.1级地震为例,探讨流体固体潮参数的时空分布特征与孕震的关系。收集2017-01~2020-07唐山古冶周边16口井水位整点值资料,通过Baytap-G程序计算分析M_(2)波与O_(1)波潮汐参数,研究M_(2)波潮汐因子随时间变化的趋势及空间分布情况。结果表明:1)唐山古冶地震前,震中附近井水位潮汐因子具有上升趋势,表现为应力积累;2)结合本次地震震源机制解可知,震中周边16口井潮汐因子的震时变化形态主要受主应力方向影响,东西向压缩,潮汐因子减小;南北向拉张,潮汐因子增大。

In order to discuss the relationship between temporal and spatial distribution characteristics of fluid solid tidal parameters and earthquakes,we take the 2020 Tangshan Guye M S5.1 earthquake as an example.We collect and analyze the water level data of 16 wells around Guye from January 2017 to July 2020.The tidal parameters of O_(1) wave and M_(2) wave are analyzed by Baytap-G program.This paper mainly studies the trend and spatial distribution of M_(2) wave tidal factors.The results show that:1)The tidal factors of wells around the epicenter before the Guye earthquake in Tangshan show an upward trend,indicating stress accumulation.2)Combined with the focal mechanism type of this earthquake,we conclude that the variation pattern of tidal factors in 16 wells around the epicenter is mainly affected by the direction of the main stress of the earthquake,and the tidal factor decreases with the compression in the east-west direction;similarly,the tidal factor increases with the extension in the north-south direction.