Crustal structure and magmatic evolution in the Pearl River Delta of the Cathaysia Block: New constraints from receiver function modeling

We used teleseismic data recorded at 17 permanent seismic stations operated by the China Earthquake Administration. Teleseismic waveforms from events with magnitudes ≥ 6.0 and with epicentral distances of 30° to 90° were chosen to estimate receiver functions beneath the stations. The earthquakes mainly occurred along the Kurile and Aleutian island arcs, north of Australia, Indonesia and the Tibet continental collision zone. The seismograms were manually checked to extract the data with high signal-to-noise ratio. The traces were windowed to include 30 s before and 100 s after the direct P-wave arrivals, and then horizontal components were rotated into radial and transverse components. We computed receiver functions using the source equalization procedure with a water-level parameter of 0.001 and a Gaussian width of 2.5. The final receiver functions were further checked based on noise level of the signals before the direct P-wave arrivals as well as the shape of the following converted phases.

本研究采用了由中国地震局运营的17个永久地震站记录的远震数据。选取了震级≥6.0且震中距在30°至90°之间的地震事件，以估算这些站点之下的接收函数。地震主要发生在堪察加和阿留申群岛弧、澳大利亚北部、印度尼西亚以及青藏高原碰撞带。对地震图进行了人工检查，以提取信噪比高的数据。将记录窗口设置为直接P波到达前30秒和到达后100秒，并将水平分量旋转为径向和横向分量。利用源匹配程序，并设置水位参数为0.001以及高斯宽度为2.5，计算接收函数。最终接收函数在直接P波到达前的信号噪声水平以及后续转换波形的形状基础上进行了进一步的检验。