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Published Online April 14, 2005
Science DOI: 10.1126/science.1109134

Reports

Submitted on December 27, 2004
Accepted on March 30, 2005

An Observation of PKJKP: Inferences on Inner Core Shear Properties

Aimin Cao 1*, Barbara Romanowicz 1, Nozomu Takeuchi 2

1 Seismological Laboratory, University of California, Berkeley.
2 Earthquake Research Institute, University of Tokyo, Japan.

* To whom correspondence should be addressed.
Aimin Cao , E-mail: acao{at}seismo.berkeley.edu

The seismic phase PKJKP, which traverses the inner core as a shear wave, and would provide direct evidence for its solidity, has been difficult to detect. Using stacked broadband records from the Gräfenberg array in Germany, we document a high signal to noise phase, whose arrival time and slowness agree with theoretical predictions for PKJKP. The back-azimuth of this arrival is also consistent with predictions for PKJKP as is the comparison with a pseudo-liquid inner core model. Envelope modeling of the PKJKP waveform implies a slightly larger shear velocity gradient with depth in the inner core than that in PREM model.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Origin of the Low Rigidity of the Earth's Inner Core.
A. B. Belonoshko, N. V. Skorodumova, S. Davis, A. N. Osiptsov, A. Rosengren, and B. Johansson (2007)
Science 316, 1603-1605
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Science. ISSN 0036-8075 (print), 1095-9203 (online)