At https://tallbloke.wordpress.com/2015/02/10/earths-core-has-a-differentia… … seismic soundings are said to have provided new information on the nature of Earth's core. Chinese and US scientists collaborated in the project – see also http://news.illinois.edu/news/15/0109.innercore_XiaodongSong.html and www.eurekalert.org/pub_releases/2015-01/ci-mli012215.php and www.principiea-scientific.org/new-study-invalidates-kirchhofa-s-law-of-t…. Tall Bloke asks, what is the implication for geomagnetism in history. Bernard Cohen and Peng Zhang are the authors of the paper, in February's Nature.
a differentiated core
13 February 2015Electromagnetism