长岛附近地区小震精定位及地震趋势分析

FINE POSITIONING FOR THE SMALL EARTHQUAKES NEAR CHANGDAO AREA AND ANALYSIS OF EARTHQUAKE TENDENCY

摘要: 对长岛附近地区(N35.8°~38.7°,E119.4°~122.9°)2000年以来数字记录的中小地震进行了双差定位,对重新定位结果的时空特征进行分析。发现双差定位后的地震与断层关系更为密切;中小地震深度具有分区差异,长岛附近较浅(平均6km),1548年7级震源区附近较深(平均13km)。结合长岛附近地区中等地震活动特点和地震活动性参数时序变化,综合分析长岛附近地区的地震趋势。

Abstract: The moderate and small earthquakes in Chang Dao area(35.8°~38.7 N°, 119.4°~122.9°E) since 2000 are relocated with double difference method.Through analysis to the results, we find that the relocated earthquakes are relevant much closer with faults.The depth of moderate and small earthquakes have regional difference, which is shallower near Changdao(6km in average), but is deeper near the source region of Ms7 event in 1548(13km in average).Combined with seismicity, the earthquake tendency of Changdao area is analyzed.