摘要
基于交错网格搜索的单台定位方法对长城站地震台2015—2017年期间记录的宽频带三分量波形数据进行了单台地震定位研究,定位了112个高信噪比的近震,获得了此期间南设得兰群岛及其周边地区的地震分布图。结果显示,地震主要沿NE向展布于南设得兰群岛及邻区,最大震级为ML4.8,最小震级为ML1.3,震源深度范围为2—134 km。相对于稳定的南极大陆内部,长城站地区的地震活动性较强,在靠近南设得兰海沟的弧前区域和布兰斯菲尔德海峡弧后区域发现了可能与俯冲和岩浆活动有关的地震事件,弧前中源深度的地震事件说明该区域可能存在俯冲作用,这直接给出了菲尼克斯板块的俯冲活动仍在继续的地震学证据。
The South Shetland Islands are located at the northern part of the Antarctic Peninsula in the West Antarctica.The region is subject to the direct or indirect influences from the Pacific Plate,the Antarctic Plate,the South American Plate,the Scotia Plate and the Phoenix Plate,which has resulted in significant tectonic activities,including subduction,rifting and volcanic magmatism.The global earthquake catalog shows that this region exhibits a higher level of seismicity in comparison to the stable Antarctic continent interior.The extreme climatic conditions of the Antarctic continent present significant challenges to seismic observation,and the level of seismological research conducted on the continent is limited.The distribution of seismic stations in the South Shetland Islands region is relatively sparse,which limits the seismic monitoring capacity of the region and consequently affects our understanding of the seismicity in the region.The Chinese Antarctic Great Wall Seismic Station(CCZ)is located on King George Island in the South Shetland Islands.Following the reconstruction and resumption of observation in 2010,the quality of seismic observation has been remarkably enhanced,thereby considerably improving the monitoring capability of small earthquakes in the Great Wall Station area and providing data support for a comprehensive understanding of the seismicity in the South Shetland Islands region.We used the single station location method of interlaced grid search to obtain earthquake catalog based on the broadband three-component waveform data recorded at CCZ during 2015−2017.Firstly,the P wave and S wave arrivals of the local seismic events are identified through visual analysis,and the events with clear Pg and Sg waves are selected for amplitude measurements.The arrival time difference,incidence angle and back azimuth of the events can be calculated.The interlaced grid search method initially establishes a set of grids for searching and location,and searching for three elements of arrival time difference,i
作者
郭钊玥
常利军
Guo Zhaoyue;Chang Lijun(Institute of Geophysics,China Earthquake Administration,Beijing 100081,China)
出处
《地震学报》
CSCD
北大核心
2024年第6期936-952,共17页
Acta Seismologica Sinica
基金
国家自然科学基金(41930218,42374079)
中国地震局地球物理研究所自主立项项目(JY2023Z01)联合资助。
关键词
长城站地震台
单台地震定位
地震活动
板块俯冲
火山活动
Antarctic Great Wall Seismic Station
single station location
seismicity
plate subducting
volcanic activity
