北京地震台地震走时表的研制

The development of travel timetable for earthquake in Beijing Seismic Station

长期地震观测发现,北京地震台实际地震记录的震相走时与全球地震走时表IASP91之间存在走时偏差。结合北京地震台及周边地下40 km精细速度结构的研究成果和AK135模型,构建其地震走时表的计算模型。通过对该地震台2003-2008年NCDSN地震观测实际走时比对,对模型结构进行修正,最终建立北京地震台地震走时表。

Basing on the long-term analysis of earthquake, we found that the seismic travel time have a little residuals between the IASP91 and the actual recording of Beijing Seismic Station. We established BJT model for computing seismic travel times which combined the velocity structure of BJT 40 km underground with AK135 model for the deeper than 40 kin. We used the real travel times from the recording of BJT station between 2003 and 2008 to modify this model. Ultimately, we have developed BJT travel-time tables. The results of comparing with natural earthquake and artificial earthquake, we found the precision of BJT travel timetable was over 38% higher than IASP91. Especially for near earthquake, the precision raised more than 50%.