CAJ | 학술논문

由于受到台站分布不理想、速度结构研究不准确以及震相拾取误差等因素的影响，常规地震定位结果精度较低。因此，研究收集了辽宁省地震台网的地震目录及震相数据，采用双差地震定位方法，对海城及其附近地区（39°N 43°N，120°E 126°E）20 a 的1400多次地震进行重新定位。与原始定位结果相比，双差定位结果表明：1）震中更加呈条带状集中，尤其在40．5°N 41．0°N，122．0°E 123．0°E 区间，与该地区的海城河大洋河断裂带走向相一致；2）该地区地震多发生于地下5～20 km，与该区中地壳存在的低速高导层相对应；3）深度剖面图显示，大部分地震沿垂直向下柱状分布，原因是该处有粉碎性破裂带，从地下25 km 处延伸到近地表。双差定位算法使得定位后均方根残差的平均值由0．74 s 下降到0．26 s。辽宁地区的地震震级与发生地震数量有关，地震数量陡然增多，大地震发生概率增大。
유우수도태참분포불이상、속도결구연구불준학이급진상습취오차등인소적영향，상규지진정위결과정도교저。인차，연구수집료요녕성지진태망적지진목록급진상수거，채용쌍차지진정위방법，대해성급기부근지구（39°N 43°N，120°E 126°E）20 a 적1400다차지진진행중신정위。여원시정위결과상비，쌍차정위결과표명：1）진중경가정조대상집중，우기재40．5°N 41．0°N，122．0°E 123．0°E 구간，여해지구적해성하대양하단렬대주향상일치；2）해지구지진다발생우지하5～20 km，여해구중지각존재적저속고도층상대응；3）심도부면도현시，대부분지진연수직향하주상분포，원인시해처유분쇄성파렬대，종지하25 km 처연신도근지표。쌍차정위산법사득정위후균방근잔차적평균치유0．74 s 하강도0．26 s。료녕지구적지진진급여발생지진수량유관，지진수량두연증다，대지진발생개솔증대。
Limited by the distribution of stations,velocity structures and the uncertainty of picking arrivals,the precision for the relocation of earthquakes is usually not sufficient.We collected the data of arrival times recorded by the seismic networks and then used the double-difference method to relocate 1 400 earthquakes occurred in Haicheng region (39°N 43°N,120°E 126°E)in the last 20 years. Comparing to the original results of the earthquake locations,the results obtained by the double-difference method in this study indicate that:1)The earthquake distributions become more convergent, especially in the region between 40.5°N and 41.0°N and between 122.0°E and 123.0°E,and more consistent with the trend of the fault along the Haicheng Dayang River;2 )Most of earthquakes occurred in the depth from 5 to 24 km,because there exists a low-velocity and high-conductivity zone in the crust;3)From the cross sections,many earthquakes distribute as a shape of columnar along the depth because there exists a comminuted fracture zone which extending from the surface to the depth of 25 km.The root-mean-square travel-time residual reduces from 0.74 s to 0.26 s after the relocation using the double-difference method.The study also indicates that the magnitude is related to the number of earthquakes in this region.If the number of earthquakes increases abruptly,the probability for the occurrence of a large earthquake increases as well.