50 Years Ago Earth

50 years ago, scientists named Earth’s magnetic field as a suspect in extinctions

Excerpt from the November 21, 1970 issue of Science News

a microscopic image showing several radiolarians

In 1970, researchers linked the extinction of several species of tiny marine organisms called radiolarians (10 living species pictured here) with reversals in the direction of Earth’s magnetic field.

Randolph Femmer/USGS

By Jonathan Lambert

- More than 2 years ago

cover of the November 21, 1970 issue

Effects of Earth’s magnetic field — Science News, November 21, 1970

Earth’s magnetic field has frequently reversed at intervals of 1 million to 100 million years.