Short-Period Surface-Wave Dispersion from Ambient Noise Tomography in Western China
Abstract
The goal of ambient noise tomography (ANT) is to improve the calibration of surface-wave propagation in aseismic areas, especially at periods shorter than 20 sec, which are hard to obtain from earthquake surface waves. In earlier work, we improved and optimized the method of ambient noise surface wave tomography for systematic application and applied it to broad-band seismic data obtained in Europe and the western part of the Middle East. The resulting phase and group speed measurements were documented in Ritzwoller et al. (2007). Current work concentrates on the application of ANT in central Asia, especially western China, where significant data resources are available. The data are taken from about 180 broad-band seismic stations including the permanent Federation of Digital Seismographic Network (FDSN), two regional networks (KZ and KN), and three temporary US PASSCAL installations in and around China: HIMNT (YL), Namche Barwa (XE), and MIT-CHINA (YA). Cross-correlations are computed in daily segments and then stacked over a three-year period (2002-2004). Rayleigh wave phase and group speed dispersion curves from 8 sec to 60 sec period are measured using a phase-matched filter, frequency-time analysis technique. The dispersion measurements from our data set are combined with those from Zheng et al. (2008) (using the China National Seismic Network) to perform ambient noise tomography. The resulting group and phase velocity maps demonstrate significant correlation with known geologic features, such as sedimentary basins and lateral variation of crustal thickness.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2008
- Accession Number
- ADA516351
Entities
People
- Michael E. Pasyanos
- Michael H. Ritzwoller
- Yingjie Yang
Organizations
- University of Colorado Boulder