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.
Carl Blesch | EurekAlert!
Wandering greenhouse gas
16.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Unique Insights into the Antarctic Ice Shelf System
14.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences