巴基斯坦地方地震台网的监控能力与可靠性

使用Bungum和Huseby方法对地方地震台网的监控能力和可靠性进行了分析。用震源位置的标准计算机码重新定位地震事件。由频率震级分布导出50％,90％和100％的累积监控能力阀值,对这些阀值23年内记录资料的监控能力水平作了估测。分析表明,在台网内发生的地震事件的台网100％监控能力水平为ML=1.7,从台网内固定实时震源对台网震源解精度作了分析。地震事件在台网内发生时,震中误差低于4km。最后讨论了地方地震台网连续运行期间影响监控能力的因素。

DETECTABILITY AND RELIABILITY OF THE LOCAL SEISMIC NETWORK IN PAKISTAN

The detectability and re1iability analysis for the local seismic network is performed employing Bungum and Husebye techniques. The events were relocated using standard computer codes for hypocentral locations. The detectability levels are estimated from the twenty-three years of recorded data in terms of 50, 90 and l00 percent cumulative detectability thresholds, which were derived from frequency-magnitude distribution.From this analysis the l00 percent level of detectability of the network is M L=l 7 for events which occur within the network. The accuracy in hypocentral solutions of the network is investigated by considering the fixed real hypocenter within the network. The epicentral errors are found to be less than 4 km when the events occur within the network.Finally, the problems faced during continuous operation of the local network, which effects its detectability, are discussed.