Receiver function based on dense arrays

为了了解地球内部的动力学并预测大地震期间的地面运动，地震学家使用地震发出的波来成像地球的结构。传统的接收函数方法以数千公里外的中等强度地震为震源，是研究接收端不连续面和沉积盆地深度的常用工具。这项研究旨在开发一种新的接收函数方法，该方法可以利用具有数百甚至数千个传感器的密集地震阵列的兴起，来产生更详细和可靠的地球图像。新的接收函数方法旨在通过直接从沿密集剖面记录的波形反演完整的接收函数图像，来克服在个别台站进行反褶积所带来的限制。这种方法将产生更高分辨率的图像，因为它更好地利用了可用的数据，并增强了相干转换。研究人员将用现有数据测试这一新方法，以拍摄中美和南美俯冲带的图像，这些俯冲带可能会产生大地震，甚至是巨型逆冲地震。此外，该方法将应用于在加利福尼亚州南部一个人口稠密的盆地收集的数据，以更好地表征未来大地震期间可能发生的地面运动。

To understand the dynamics of Earth's interior and predict ground motions during large earthquakes, seismologists use waves emitted from earthquakes to image structures of the Earth. The traditional receiver function method, which uses medium-size earthquakes thousands of kilometers away as sources, is a popular tool in studying receiver-side discontinuities and depth of sedimentary basins. This research aims to develop a new receiver function method that can take advantage of the rise of dense seismic arrays with hundreds or even thousands of sensors, to produce more detailed and reliable images of the Earth. The new receiver-function methodology aims to overcome the limitations introduced by deconvolution at individual stations, by inverting for full receiver function images directly from the waveforms recorded along a dense profile. This approach will produce higher-resolution images because it makes better use of available data and enhances coherent conversions. The researchers will test this new method with available data to image subduction zones in Middle and South America that can generate large or even mega-thrust earthquakes. Additionally, the method will be applied to data collected in a densely populated basin in southern California to better characterize possible ground motions during future large earthquakes.