Regional wave propagation characteristics and velocity structure in Asia
- 出版日期：2000.
- 页数：108 p. :
- 第一责任说明：Rapine, Richard Ronald Rapine.
- 分类号：a263.2
- ISBN：0493023089(ebk.) :
MARC全文
62h0021681 20140523101410.0 cr un||||||||| 101222s2000 xx ||||f|||d||||||||eng | AAI9993800 0493023089(ebk.) : CNY371.35 UnM UnM NGL a263.2 Rapine, Richard Ronald. Regional wave propagation characteristics and velocity structure in Asia [electronic resource] / Rapine, Richard Ronald Rapine. 2000. 108 p. : digital, PDF file. Chair: James F. Ni. ; Source: Dissertation Abstracts International, Volume: 61-11, Section: B, page: 5768. Thesis (Ph.D.) -- New Mexico State University, 2000. One of the most tectonically active continental regions in the world is in east Asia where continental collision occurs. In this dissertation an extensive study of seismic wave propagation recorded from earthquakes and nuclear explosions in China and its surrounding regions is presented. High-frequency Sn and Lg wave amplitude ratios are used to map lateral variations of shear wave attenuation. The anelasticity of the crust is quantified by calculating crustal Q. Lg Q values in China and Southeast Asia are very low (100–300) when compared to the stable part of continents. Broadband surface wave data collected within Tibet during the last decade are analyzed to determine crustal velocity structure there. The dispersion of Rayleigh waves reveals significant south to north structural variation. S wave velocities are higher in the lower crust and upper mantle in southern Tibet than in the north. This along with other geophysical data suggests that the cold Indian lithosphere has only underthrust Tibet to -32°N.;The presence of partial melt in the crust and mantle can explain many of the propagation characteristics and seismic velocities that are observed in Asia. Crustal melt attenuates Lg waves while melt in the upper mantle reduces or eliminates Sn amplitudes. Melt in the upper mantle beneath northern Tibet intrudes into the lower crust and is the likely cause of the low shear wave velocities seen there. This melt is a result of the complex tectonic processes in Asia which have occurred in the past and continue to the present. The most prominent effects are due to the continental collision between India and Eurasia and the subduction of the Pacific plate beneath east Asia. These processes have extensively influenced the regional tectonics from southern Asia to Siberia. Seismic waves. New Mexico State University. aCN bNGL http://pqdt.bjzhongke.com.cn/Detail.aspx?pid=HEUJtKRAlLo%3d NGL Bs712 rCNY371.35 ; h1 bs1101