High-Resolution Seismic Velocity and Attenuation Structure of the Sichuan-Yunnan Region, Southwest China, Using Seismic Catalog and Waveform Data

摘要

The Sichuan-Yunnan region in southwestern China lies in the transition zone between the uplifted Tibetan plateau to the west and the Yangtze continental platform to the east. This region has a very complicated geological structure and is one of the most active areas of continental earthquakes in the world. This two-year project is to develop high-resolution models of the velocity and attenuation structure of the Sichuan-Yunnan region (longitudes approximately 97-108 degrees E and latitudes approximately 21-35 degrees N) using seismic catalog and waveform data. There are four main components in this project: (1) using waveform alignment methods (waveform cross-correlation and bispectrum analysis) to obtain more accurate differential arrival times, (2) using regional scale adaptive-grid double-difference tomography to obtain detailed P- and S-wave velocity models of the Sichuan-Yunnan region, (3) using the adaptive- grid triple-difference seismic attenuation method to determine the detailed attenuation structure for both Qp and Qs for the Yunnan region, and (4) assembling a ground truth database.