Taxonomy term

paleomagnetism

Extinct lunar magnetic field lasted longer than previously thought

Magnetized lunar rocks collected by the Apollo missions indicate the moon had its own magnetic field, generated by motion of liquid metal in its core, until at least 3.2 billion years ago. However, what powered the lunar field and how long it lasted has been unclear. Now, new research reveals that the lunar magnetic field lasted until at least 2.5 billion years ago, and possibly even until 1 billion years ago.

17 Nov 2017

Permian-Triassic extinctions timed differently on land and at sea

Life on land and in the sea was nearly eradicated about 252 million years ago in the largest-known mass extinction. The cataclysm, known as the Permian-Triassic (P-T) mass extinction, was likely driven by extensive flood basalt volcanism in Siberia and is thought to have affected global biodiversity simultaneously. However, based on analyses of rocks deposited around the time of the P-T boundary in the Karoo Basin of South Africa, scientists suggest in a new study that the terrestrial turnover in vertebrates occurred earlier than the marine extinction. If true, a second trigger — other than Siberian volcanism — might need to have occurred to explain both events.
 
31 Jan 2016

Brooks Ellwood and the unusual applications of magnetism

The call came out of the blue. Geophysicist Brooks Ellwood was sitting in his office in the geology department at the University of Texas at Arlington in 1990 when the telephone rang. On the other end was Doug Owsley, a forensic anthropologist at the Smithsonian Institution, who was calling to ask for Ellwood’s help to find the grave of “Wild Bill” Longley. Little did Ellwood realize that this seemingly straightforward request would set him off on a 10-year quest and a career he never anticipated.

10 Mar 2014

Mediterranean mammals migrated prior to the Messinian Salinity Crisis

The people of the Iberian Peninsula and North Africa share a long and complicated history, evident in culinary and genetic similarities, due in large part to their close proximity. Now it appears that the animals of the region have shared an even longer history. Researchers studying mammal fossils in Spain and Morocco recently determined that a migration event between the Iberian Peninsula and North Africa occurred more than 6 million years ago — more than half a million years earlier than previously thought.

19 Jul 2013