断层气CO_2快速测定方法在四川地震预测中的应用

The Fast-detection Technique for Fault Gas CO_2 and Its App lication to the Earthquake Prediction in Sichuan Province

介绍了快速测定活动断层带CO2 气体的方法、川西地区断层气CO2 观测点的选建以及观测的情况。初步的观测结果显示 ,在 1999年四川绵竹两次 5 0级地震、 2 0 0 1年四川雅江 5 0级和 6 0级地震和 2 0 0 1年云南永胜 6 0级地震前 ,部分观测点的断层气CO2 均有很好的短期前兆异常显示。实践表明 :直接埋设在断层破碎带上的观测点比埋在第四纪松散堆积层中的观测点更能观测到来自地壳内部的、可能与地震前兆有关的断层气CO2 的异常信息。

The fast-detection technique for fault-gas Carbon Dioxide (CO 2) running o ut of active fault zones, the selecting and building of observational sites as w ell as the observational situation for fault-gas CO 2 in western Sichuan are introduce d in this parer. Prelimi nary observational results show that the perfect short-term precursory anomaly o f CO 2 was observed at relevant sites prior to the occurrences of two M5 0 eart hquakes near Mianzhu in 1999, the occurrences of M5 0 and M6 0 earthquak es south of Yajiang in 2001 and the occurrences of M6 0 eart hquake near Yongsheng in Yunnan Province in 2001. The practice sug gests that anomalous information of fault-gas CO 2 coming from the deep insid e of the earth's crust and possibly being related to earthquake precursor at sites built directly on broken fault zones can be observed more possibly at sites bui lt directly on broken zones of fault than those built on loose Quaternary depos its which bury the fault zones.