福建地壳运动与地震关系初探

利用福建地震台网88个地震台站于2015年记录的10个月的连续波形数据，基于台网约束下的长短窗特征触发式震相检测的模板事件识别方法和匹配滤波自动检测方法，识别出模板事件919个，匹配滤波后重新识别和定位了共计2 243个地震事件，其中M_L1.0以上地震1 991次，主要集中在M_L1.0—1.5之间，这极大扩充了该震级范围内的福建地震台网目录。重新定位的地震震源深度分布在0—20 km之间，多数发生在10 km内的上地壳。沿长乐—诏安断裂带和永安—晋江断裂带，地震分布集中且表现出明显的分段活动性。在长乐—诏安断裂带上检测到较福建台网目录更多的地震，且地震活动性表现为西南段较强、东北段较弱，沿断裂带的震源深度分布由南向北逐渐变浅，与莫霍面深度的变化相一致；在与之共轭的永安—晋江断裂带上则北西段地震活动更为集中，而东南段地震活动稍显分散。重新识别与精定位后的地震与福建地区地壳水平形变南强北弱、东强西弱的特点相一致。

Study on the relationship between crustal movement and seismicity in Fujian area

Driven by the tectonic loading of Taiwan and Taiwan Strait, there are several large Quaternary fracture zones in the Fujian area, with strong historical and current seismicity. We build a comprehensive seismic catalog with a new automatic workflow called PALM （phase picking, association, location, matched filter）, which combines STA/LTA and matched filter. PALM is applied to 10 month’s continuous data in 2015 of 88 stations from the Fujian Earthquake Agency. We recognized 919 template events and finally relocated 2 243 events after matching filter, among which 1 991 events with magnitude greater than M_L1.0, and it greatly expanded the catalog from Fujian Earthquake Agency in the range of M_L1.0−1.5. The depth of relocated earthquake events are distributed between 0 and 20 km, with most of them occurred within 10 km. The events are concentrated along Changle-Zhao’an fault zone and Yong’an-Jinjiang fault zone and showed obvious segmental activity. We detected more earthquakes than the catalog from Fujian Earthquake Agency, and the seismicity was stronger in the southwest section and weaker in the northeast section. The depth distribution along the fault zone became shallower from south to north, which was consistent with the change of Moho depth. Besides, we can see a highly clustered feature of seismicity at northwest section and slightly dispersed at southeast segment in Yong’an-Jinjiang fault zone, which forms a conjugate shape with Changle-Zhao’an fault zone. The repicked and relocated events in Fujian area was consistent with the characteristics of horizontal crustal deformation, which was stronger in south and east while weaker in north and west.