HR: 0800h
AN: T41A-1274    [Abstracts]
TI: Short-period surface-wave amplitude tomography of China
AU: * Hearn, T M
EM: thearn@nmsu.edu
AF: New Mexico State University, Physics Department, Las Cruces, NM 88003 United States
AU: Wang, S
EM: suyunw@163bj.com
AF: Institute of Geophysics China Earthquake Administration, China Earthquake Administration, Beijing, 100081 China
AU: Pei, S
EM: peisp@itcas.ac.cn
AF: Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100085 China
AU: Ni, J F
EM: jni@nmsu.edu
AF: New Mexico State University, Physics Department, Las Cruces, NM 88003 United States
AU: Zhonghai, X
EM: xuzh@cea-iqp.ac.cn
AF: Institute of Geophysics China Earthquake Administration, China Earthquake Administration, Beijing, 100081 China
AU: Yu, Y
EM: yanxiang@cdsn.org.cn
AF: Institute of Geophysics China Earthquake Administration, China Earthquake Administration, Beijing, 100081 China
AB: Amplitude data from the Annual Bulletin of Chinese Earthquakes are routinely collected to estimate the surface-wave magnitudes for regional events. We have used these data to construct amplitude tomography map of China with regionally varying attenuation. Qs values average around 200. There are clear correlations between the attenuation and regional structures. Sedimentary basins are clearly identifiable by their high attenuation - particularly Bohai Basin. Continental rifts surrounding the Ordos Plateau and the Panxi rift also have high attenuation. Amplitude data are measured along with a period measurement that comes from the pulse width at maximum amplitude. Periods range from 0.2 to 24 seconds corresponding to surface waves that propagate primarily within the upper crust. Both source size and propagation path affects these periods. Larger sources have larger periods and these are used to investigate source models. Attenuation maps made for different periods ranges have similar structures; however, attenuation at higher frequencies is stronger than that of lower frequencies.
DE: 7255 Surface waves and free oscillations
DE: 7270 Tomography (6982, 8180)
DE: 8110 Continental tectonics: general (0905)
SC: Tectonophysics [T]
MN: Fall Meeting 2005