Shear-wave velocity structure of upper mantle under Taiwan from the array analysis of surface waves

• Published in: Geophysical research letters Vol. 32; no. 7; pp. L07310 - n/a
• Main Authors: Hwang, Ruey-Der, Yu, Guey-Kuen
• Format: Journal Article
• Language: English
• Published: American Geophysical Union 01.04.2005; Blackwell Publishing Ltd
• Subjects: Continental crust; Lithosphere; Mantle; Seismology; Surface waves and free oscillations
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2004GL021868

A one‐dimensional shear‐wave velocity structure in the top 200 km of upper mantle under the Central Range (CR) of Taiwan was proposed from inversion of fundamental‐mode Rayleigh‐wave phase velocity, which is determined from array analysis. Crust under CR has relatively low velocities with the thickness of 40–50 km when comparing with other regions in Taiwan. This might imply the existence of a mountain root. Upper‐mantle low velocity zone with S‐wave velocities of about 4.25∼4.4 km/sec is also derived. The thin lid (∼30 km) with a relatively high velocity of 4.90 km/sec reveals the probable connection with the lithosphere of the Eurasian plate. The overall thickness of lithosphere under CR is about 80 km, which is approximate to those under the adjacent sea areas of China. In other words, the upper mantle beneath CR is a part of the Eurasian plate.