Evidence for a ubiquitous seismic discontinuity at the base of the mantle

被引:131
作者
Sidorin, I [1 ]
Gurnis, M [1 ]
Helmberger, DV [1 ]
机构
[1] CALTECH, Seismol Lab 252 21, Pasadena, CA 91125 USA
关键词
D O I
10.1126/science.286.5443.1326
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
A sharp discontinuity at the base of Earth's mantle has been suggested from seismic waveform studies; the observed travel time and amplitude variations have been interpreted as changes in the depth of a spatially intermittent discontinuity. Most of the observed variations in travel times and the spatial intermittance of the seismic triplication can be reproduced by a ubiquitous first-order discontinuity superimposed on global seismic velocity structure derived from tomography. The observations can be modeled by a solid-solid phase transition that has a 200-kilometer elevation above the core-mantle boundary under adiabatic temperatures and a Clapeyron slope of about 6 megapascal per kelvin.
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页码:1326 / 1331
页数:8
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