Inner Core Differential Motion Confirmed by Earthquake Waveform Doublets

doi:10.1126/science.1113193

Account Information

Guest Alerts | Access Rights | My Account | Sign In

Site Navigation

Article Views

VERSION HISTORY

Correction for this article

Article Tools

My Science

Science 26 August 2005:
Vol. 309. no. 5739, pp. 1357 - 1360
DOI: 10.1126/science.1113193

Prev | Table of Contents | Next

Reports

Inner Core Differential Motion Confirmed by Earthquake Waveform Doublets

Jian Zhang,¹^* Xiaodong Song,²^* Yingchun Li,² Paul G. Richards,¹ Xinlei Sun,² Felix Waldhauser¹

We analyzed 18 high-quality waveform doublets with time separationsof up to 35 years in the South Sandwich Islands region, forwhich the seismic signals have traversed the inner core as PKP(DF).The doublets show a consistent temporal change of travel timesat up to 58 stations in and near Alaska, and they show a dissimilarityof PKP(DF) coda. Using waveform doublets avoids artifacts ofearthquake mislocations and contamination from small-scale heterogeneities.Our results confirm that Earth's inner core is rotating fasterthan the mantle and crust at about 0.3° to 0.5° peryear.

¹ Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA.
² Department of Geology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.

^* These authors contributed equally to this work.

To whom correspondence should be addressed. E-mail: xsong{at}uiuc.edu

Read the Full Text

The editors suggest the following Related Resources on Science sites:

In Science Magazine

NEWS OF THE WEEK GEOPHYSICS: Earth's Inner Core Is Running a Tad Faster Than the Rest of the Planet: Richard A. Kerr (26 August 2005)
Science 309 (5739), 1313a. [DOI: 10.1126/science.309.5739.1313a]
| Summary » | Full Text » | PDF »

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:

Short wavelength topography on the inner-core boundary.: A. Cao, Y. Masson, and B. Romanowicz (2007)
PNAS 104, 31-35
| Abstract » | Full Text » | PDF »