Abstract:

Following M7.8 Tangshan earthquake of 1976,6 moderate-strong earthquakes with magnitude of greater than 5 and a sequence of moderate-small earthquakes with magnitude of greater than 3.5 had occurred successively in the capital circle untill 1991, such as M6.9 Ninghe earthquake of 1976 and M6.1 Datong earthquake of 1989 and so forth. A distinct increase of anomalous cocentration of hydrogen in thermal underground water might be observed by the hydrochemical monitoring network lying in the Beijing area preceding or following moderate-strong earthquakes and parts of moderate-small earthquakes, with its amplitude up to a few times or more than ten times, even to tens,of times the normal background value, which returned to the normal following the earthquake, suggesting that groundwater hydrogen forms a part of geochemical compositions sensitive to the stress-strain of the layers and also that it is a hopeful tool for the prediction of earthquakes.

Key words: Hydrogen, Sensitive element, Capital circle

摘要：

1976年唐山7.8级地震之后,到1991年底,首都圈地区先后发生了宁河6.9级、大同6.1级等6次5级以上中强地震和一系列3.5级以上中小地震,每次中强地震和部分中小地震前后,北京地区水化监测井网均能监测到地下热水中氢气含量明显的异常上升变化,其幅度达正常背景值的几倍、十几倍、几十倍甚至更高,震后均逐渐恢复正常,这表明地下氢气是反应地下应力应变灵敏的地球化学组分,也是地震预报很有希望的前兆手段之一。

关键词: 氢气, 灵敏元素, 首都圈地区