This page is mostly a list of links, to papers, abstracts and a press release, in which the concept of inner-core rotation is presented and debated.

Jeffreys Lecture given by Richards at a meeting of the Royal Astronomical Society.

This lecture, given in London in March 1999, in part used unpublished material describing the work of Song (then of Columbia/Lamont, now with the University of Illinois), Laske and Masters (of the University of California at San Diego), Woodhouse and his colleagues at Oxford University, and Li (of Columbia/Lamont).

Because it was not appropriate for the written version of the lecture to include material not accepted for publication, the written version did not appear until the February 2000 issue of Astronomy & Geophysics, the Journal of the Royal Astronomical Society.

The above link is a slightly longer version than that published in A & G. In particular, the last figure is new. It is from Xiaodong Song, and indicates that systematic travel time change on the path from the South Sandwich Islands to stations in Alaska can be detected with data just from the decade of the 1990s.

Selected AGU Abstracts, most from the December 1999 meeting in San Francisco and one from the 1998 Spring meeting in Boston

At the December 1999 meeting, key papers by Vidale, Dodge and Earle (paper U21B-07) and Song (paper U21B-05) presented new observations supporting the case for inner core rotation in an easterly direction at the rate of a few tenths of a degree per year. The Spring 1998 Abstract is from Dziewonski and Su, stating that their new analysis (of ISC data) "implies a zero, non-detectable, rotation rate."

Science perspective article, by Annie Souriau

This article, from the 1998 July 3 issue of Science, questioned the reality of Song and Richards' claim (in the 1996 July 18 issue of Nature) to have detected systematic travel time changes --- and hence questioned the reality of inner core rotation.

reply to Souriau, published in Science online

Here, Richards, Song and Li respond to Souriau's Science perspective article, and she replies to our remarks.

Headlines

Numerous newspapers wrote articles on inner core rotation following publication of the July 1996 Nature article.

the original material provided as a press release in 1996

Xiaodong Song and I gave a press conference in July 1996 on the Columbia University campus -- and then flew to Australia, where we found news of our work in the local newspapers.

Here we see the cut-away Earth, packaging the outer and inner cores (why don't they fall out?), arriving at Lamont Hall.

Richards' home page at Lamont