Evidence from Hawaiian volcanoes shows that Earth recycles its crust

November 29, 2006
Earth

A geologist at Rutgers, The State University of New Jersey, has come up with evidence our planet practices recycling on a grand scale.

Writing in the prestigious British science journal Nature, geological sciences professor Claude Herzberg offers new evidence that parts of the Earth’s crust that long ago dove hundreds or thousands of kilometers into the Earth’s interior have resurfaced in the hot lava flow of Hawaiian volcanoes.

“This concept has been a big issue in the earth sciences,” Herzberg said. While it had been proposed earlier by some geologists, the profession hasn’t embraced it because evidence until now remained sketchy. “Many geologists felt that when Earth’s crust was forced deep into the mantle, a process called subduction, it would simply stay there.”

Herzberg claims to have found telltale chemical evidence at Mauna Kea that pieces of this submerged crust have been forced up through plumes and now make up most of this volcano’s lava flow. “The low calcium in the Hawaiian magma pegs it as crust that had melted and been forced to the surface,” he said. The calcium levels in traditional magma, which comes from melting the Earth’s mantle layer below the crust, are much higher.

Herzberg said his research doesn’t stop in Hawaii and that his chemical findings will be useful in understanding the makeup and action of other volcanoes around the world. These findings extend beyond calcium and include sulfur, along with isotopes of the heavier elements hafnium and lead that are tracers for clays and other materials that originated close to the surface prior to subduction.

“Chemical patterns we’ve found elsewhere used to be puzzles but are now starting to make sense,” he said.

Still, the big island of Hawaii remains the prime site for uncovering the secrets of volcanic action, as it has the largest volcanoes on Earth and is the most productive in terms of lava outpouring. Herzberg believes the information he’s uncovered about magma chemistry might one day help scientists predict eruptions, as different chemical abundances show up at different times in the volcanoes’ eruption cycles.

Source: Rutgers, the State University of New Jersey

Explore further: Seven SMD-supported instruments to search for evidence of life on Europa

Related Stories

Recommended for you

Land-based microbes may be invading and harming coral reefs

March 24, 2017

A new study suggests that coral reefs—already under existential threat from global warming—may be undergoing further damage from invading bacteria and fungi coming from land-based sources, such as outfall from sewage ...

Managing bushfires for safety and biodiversity

March 24, 2017

People have long used planned fires as a tool to open up access to hunting grounds, to encourage new plant growth, and to cultivate plants for cooking, heating and spiritual purposes.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.