[关键词]
[摘要]
本文梳理了我国地震目录的产出现状,对于我国近几年应急机构和区域台网产出的震源机制解、矩震级进行了比较研究。结果表明:中国地震局地球物理研究所和地震预测研究所对于国内陆地地区6 级以上地震的地震矩张量解的产出率为100% ,5 级以上地震的地震矩张量解产出率为81% 。这两个研究所给出的3 种矩张量结果和GCMT 给出的矩张量结果较为一致,类型统计一致率分别达到71% 、86% 和66% ,其中P、T 轴空间夹角优势分布在15°左右。产出的矩震级和GCMT 解得到的矩震级相差不大,偏差在0. 1 以内的比率分别为46% 、86% 和71% ,偏差在0. 3 以内的比率分别为85% 、100% 和97% 。结果表明对于我国内陆地区的5 级以上地震,这两个研究所产出率较高、结果较为一致。而由各台网据震源参数得出的5 级左右地震的矩震级和GCMT 求解的矩震级比较起来明显偏小。由此探讨了在传统地震目录中增加震源机制解及矩震级的必要性。
[Key word]
[Abstract]
We reviewed the current situation of the earthquake catalog report in China,and carried out a comparative study of the focal mechanism and moment magnitude reported by earthquake emergency response agencies and local seismic networks in recent years. The results showed: the seismic moment tensor reported by two emergency units which were Institute of Geophysics and Institute of Earthquake Science,China Earthquake Administration is the rate of 100% for all earthquakes having occurred over the domestic land areas with the magnitude of M≥ 6. 0,and the rate was 81% for M≥5. 0. The three kinds of seismic moment tensor given by the two emergency units was similar with the seismic moment tensor given by GCMT. In accordance with the seismic moment tensor type classification,the statistical concordance rate reached respectively 71%,86% and 66%,where the P,T-axis angle of spatial distribution was mainly about 15°. The difference of the moment magnitude was relatively small between two emergency units and GCMT. The deviation ratios of 0. 1 were respectively 46%,86% and 71% . The variation ratios of 0. 3 were respectively 85%,100% and 97% . The results showed that for the earthquakes over the domestic land areas and magnitude with M≥5. 0 both units output rates are higher and more consistent. The local seismic network reporting moment magnitude about M5. 0 derived from the source parameters and GCMT solving moment magnitude is significantly smaller in comparison. Thus under the current circumstances we discussed the feasibility of an increase of focal mechanism and moment magnitude on the basis of traditional earthquake catalog.
[中图分类号]
[基金项目]
地震行业科研专项(201308008)资助