2018 new SRL paper “Shallow crustal structure of the middle-lower Yangtze River region in eastern China from surface wave tomography of a large volume airgun shot experiment”
Shallow crustal structure of the middle-lower Yangtze River region in eastern China from surface wave tomography of a large volume airgun shot experiment
Yuyang She1, Huajian Yao1,2*, Qiushi Zhai1, Fuyun Wang3, Xiaofeng Tian3
1Laboratory of Seismology and Physics of Earth’s Interior & School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, China
2Mengcheng National Geophysical Observatory, University of Science and Technology of China, Mengcheng, Anhui, China
3Geophysical Exploration Center, China Earthquake Administration, Zhengzhou, Henan, China
*Corresponding Author: Huajian Yao (hjyao@ustc.edu.cn)
Abstract :
Airgun source excited in land water bodies got rapid advancement and application in geophysics as an environmentally friendly active source. Its high repeatability is an important feature that is different from other active sources and has important application values. A large volume airgun-shot experiment was conducted during 10–20 October 2015 in the YangtzeRiver in the Anhui Province of eastern China. This area is an important polymetallic metallogenic belt and mineral resourcebase. To better understand the structure in this area, we perform 3D high-frequency surface-wave tomography to investigate the shallow crustal shear-velocity structure in the middle lower Yangtze River region, using airgun signal recorded by dense arrays in this experiment. The direct surface-wave tomographic method with period-dependent raytracing is used to invert all surface-wave group-velocity dispersion data in the 0.1–1.6 s period band simultaneously for 3D variations of shear-velocity structures in the shallow crust. Our results show a good correspondence to the geological features, with relatively high shear velocity in the metallic deposit fields and low shear velocity mainly along the Yangtze River. Our shallow crustal velocity model can provide useful information for future geophysical exploration of concealed deposits and help us better understand the shallow tectonic features in this area.
