Tectonic Plates Come Apart at the Seams
The content you've requested is available without charge only to active Sigma Xi members and American Scientist subscribers.
If you are an active member or an individual subscriber, please log in now in order to access this article.
If you are not a member or individual subscriber, you can:
At a rate of a few centimeters per year, the movement of continents is imperceptible to transient beings like ourselves. But over geologic time, the land masses that define the world of our senses have cruised around the globe, smashing together and ripping apart. Pangea, the supercontinent that broke up more than 100 million years ago, was only the most recent union of Earth's landmasses. Supercontinents and superoceans have been forming and disappearing for 3 billion years. But why do supercontinents split at one site and not another? The answer to this question is several hundred million years older than Pangea, dating back to the breakup of the previous supercontinent. The mountainous sutures of old continental collisions, it seems, carry the seeds of the next continental dispersion.
Connect With Us:
An early peek at each new issue, with descriptions of feature articles, columns, and more. Every other issue contains links to everything in the latest issue's table of contents.News of book reviews published in American Scientist and around the web, as well as other noteworthy happenings in the world of science books.
To sign up for automatic emails of the American Scientist Update and Scientists' Nightstand issues, create an online profile, then sign up in the My AmSci area.
JSTOR, the online academic archive, contains complete back issues of American Scientist from 1913 (known then as the Sigma Xi Quarterly) through 2005.
The table of contents for each issue is freely available to all users; those with institutional access can read each complete issue.
View the full collection here.
Receive notification when new content is posted from the entire website, or choose from the customized feeds available.