HR: 1330h
AN: S32B-0848    [PDF]
TI: A Comparative Study of Intermediate-Period Surface Waves From Kiloton-Size Mining Explosions in Northeast China and Western United States
AU: * Zhou, R
EM: zhou@passion.isem.smu.edu
AF: Southern Methodist University, Dept. of Geological Sciences P.O. Box 750395, Dallas, TX 75275-0395 United States
AU: Stump, B W
EM: stump@passion.isem.smu.edu
AF: Southern Methodist University, Dept. of Geological Sciences P.O. Box 750395, Dallas, TX 75275-0395 United States
AU: Chen, Y
EM: chenyt@cdsn.org.cn
AF: Institute of Geophysics, China Seismological Bureau, Beijing, 100081 China
AB: Kiloton size mining explosions are typically used to remove overburden or to fragment rocks for resource recovery. Large mining explosions are conducted with delays between individual charges in an array resulting in source durations as great as several seconds. The total size of the explosion, its time duration and spatial characteristics can generate short- to intermediate-period (2-20 sec) surface waves. These intermediate period surface waves provide the opportunity to constrain upper crustal shear structure and attenuation. We report on a comparative study using regional seismic data generated by mining explosions in Northeast China and Western United States. The regional surface waves from the Western US were generated by a large-scale cast blast in a Wyoming coal mine. The intermediate-period surface waves in Northeast China were generated by a mining explosion in an iron mine. Two seismic networks with STS-2 broadband seismometers were deployed around the coal-mine and close to the iron-mine at regional distances. Fundamental mode Rayleigh waves were generated by these two mining explosions and are utilized to constrain the crustal structure in each region regions. The group velocities of fundamental mode Rayleigh wave were determined by using the multiple filter analysis and refined by phase matched filtering technique. The surface wave dispersion curves covered the period range of 2 to 18 sec for the coal-mine explosion with group-velocities range from 1.3 to 3.0 km/sec and 1.5 to 10 sec from the iron-mine explosion with the group-velocities range from 2.6 to 3.3 km/sec, respectively. Station specific velocity models were determined for each station and are consistent with the known shallow crustal structure in each area.
DE: 7255 Surface waves and free oscillations
SC: Seismology [S]
MN: 2003 Fall Meeting