Featured Research

from universities, journals, and other organizations

Lava formations in Western U.S. linked to rip in giant slab of Earth

Date:
February 15, 2012
Source:
University of California, San Diego
Summary:
Scientists have proposed mass melting as a new force behind volcanic activity in the Columbia River region.

A new model by Scripps researchers details a rupture inside the Farallon slab that caused a magma flow now known as Columbia River flood basalt in the Western U.S.
Credit: Image courtesy of University of California, San Diego

Like a stream of air shooting out of an airplane's broken window to relieve cabin pressure, scientists at Scripps Institution of Oceanography at UC San Diego say lava formations in eastern Oregon are the result of an outpouring of magma forced out of a breach in a massive slab of Earth. Their new mechanism explaining how such a large volume of magma was generated is published in the Feb. 16 issue of the journal Nature.

Related Articles


For years scientists who study the processes underlying the planet's shifting tectonic plates and how they shape the planet have debated the origins of sudden, massive eruptions of lava at the planet's surface. In several locations around the world, such "flood basalts" are marked by immense formations of volcanic rock. A famous example is India's Deccan flood basalt, a formation widely viewed as related to the demise of the dinosaurs 65 million years ago.

Such eruptions are thought to typically occur when the head of a mantle plume, a mushroom-shaped upwelling of hot rock rising from deep within Earth's interior, reaches the surface. Now Scripps postdoctoral researcher Lijun Liu and geophysics professor Dave Stegman have proposed an alternative origin for the volcanic activity of Oregon's Columbia River flood basalt.

Liu and Stegman argue that around 17 million years ago the tectonic plate that was subducting underneath the western United States began ripping apart, leading to massive outpourings of magma. Their proposed model describes a dynamic rupture lasting two million years -- a quick eruption in geological terms -- across the so-called Farallon slab, where the rupture spread across 900 kilometers (559 miles) along eastern Oregon and northern Nevada.

"Only with a break of this scale inside the down-going slab can we reach the present day geometry of mantle we see in the area," said Liu, "and geochemical evidence from the Columbia River lavas can also be explained by our model."

"When the slab is first opened there's a little tear, but because of the high pressure underneath, the material is able to force its way through the hole. It's like in the movies when a window breaks in an airplane that is at high altitude -- since the cabin is at higher pressure, everything gets sucked out the window," said Stegman, an assistant professor with Scripps' Cecil H. and Ida M. Green Institute of Geophysics and Planetary Physics.

Liu and Stegman came upon their new mechanism by attempting to describe how the complicated structure of Earth's mantle under the western U.S. developed during the past 40 million years. The final state of their model's time-evolution matches the present day structure as imaged by the USArray, the National Science Foundation's transportable seismic network of 400 sensor stations leapfrogging across the United States.

The John Miles Fellowship, the Cecil and Ida Green Foundation and the G. Unger Vetlesen Foundation funded the study.


Story Source:

The above story is based on materials provided by University of California, San Diego. Note: Materials may be edited for content and length.


Journal Reference:

  1. Lijun Liu, Dave R. Stegman. Origin of Columbia River flood basalt controlled by propagating rupture of the Farallon slab. Nature, 2012; 482 (7385): 386 DOI: 10.1038/nature10749

Cite This Page:

University of California, San Diego. "Lava formations in Western U.S. linked to rip in giant slab of Earth." ScienceDaily. ScienceDaily, 15 February 2012. <www.sciencedaily.com/releases/2012/02/120215142814.htm>.
University of California, San Diego. (2012, February 15). Lava formations in Western U.S. linked to rip in giant slab of Earth. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/2012/02/120215142814.htm
University of California, San Diego. "Lava formations in Western U.S. linked to rip in giant slab of Earth." ScienceDaily. www.sciencedaily.com/releases/2012/02/120215142814.htm (accessed October 24, 2014).

Share This



More Earth & Climate News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

EU Gets Climate Deal, UK PM Gets Knock

EU Gets Climate Deal, UK PM Gets Knock

Reuters - Business Video Online (Oct. 24, 2014) EU leaders achieve a show of unity by striking a compromise deal on carbon emissions. But David Cameron's bid to push back EU budget contributions gets a slap in the face as the European Commission demands an extra 2bn euros. David Pollard reports. Video provided by Reuters
Powered by NewsLook.com
Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Raw: Tornado Rips Roofs in Washington State

Raw: Tornado Rips Roofs in Washington State

AP (Oct. 24, 2014) A rare tornado ripped roofs off buildings, uprooted trees and shattered windows Thursday afternoon in the southwest Washington city of Longview, but there were no reports of injuries. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Fast-Moving Lava Headed For Town On Hawaii's Big Island

Fast-Moving Lava Headed For Town On Hawaii's Big Island

Newsy (Oct. 24, 2014) Lava from the Kilauea volcano on Hawaii's Big Island has accelerated as it travels toward a town called Pahoa. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins