Crustal S-Wave Q Estimated from M_L amplitude Ⅱ: Q Lateral Variation in China

详细信息   

• 责任者：Wang Suyun (Institute of Geophysics ; China Earthquake Administration ; Beijing 100081 ; China) ; Pei Shunping
• 刊名：Chinese Journal of Geophysics
• 出版年：2008
• 卷期：51(1)
• 关键词：地壳 ; crust ; Q值 ; Q value ; 中国 ; China
• 页码：p.133-139
• 图表：5 illus., 32 refs.
• 分类号：0400
• issnNo：ISSN0001-5733
• isbnNo：CN11-2074/P

摘要

Over 54 000 S-wave amplitude and period data reported in the Annual Bulletin of Chinese Earthquakes (1984-2004) for ME determination were used to study the S wave attenuation and the regional variation of crustal attenuation in China. A two-dimensional tomography method is adopted to find regional attenuation variation. The authors obtained an average Q₀ (Q at 1 Hz) value of 370 for the entire studied region with regional fluctuations ±200. Features larger than 2 degrees in most parts of China are well resolved and map directly to geologic provinces. Regions with the lowest attenuation (high Q₀ values) are beneath the Tarim Basin, Sichuan Basin, Ordos Platform, and South China Block. These tend to be tectonically inactive regions that are generally dominated by intrusive and cratonic rocks in the upper crust.