Scientists have discovered the world's longest known chain of continental volcanoes, running 2,000 kilometers across Australia, from the Whitsundays in North Queensland to near Melbourne in central Victoria
Scientists have discovered the world's longest known chain of continental volcanoes, running 2,000 kilometres across Australia, from the Whitsundays in North Queensland to near Melbourne in central Victoria.
The volcanic chain was created over the past 33 million years, as Australia moved northwards over a hotspot in the Earth's mantle, said leader of the research Dr Rhodri Davies from The Australian National University (ANU).
"We realised that the same hotspot had caused volcanoes in the Whitsundays and the central Victoria region, and also some rare features in New South Wales, roughly halfway between them," said Dr Davies, from the ANU Research School of Earth Sciences.
"The track is nearly three times the length of the famous Yellowstone hotspot track on the North American continent," said Dr Davies.
This kind of volcanic activity is surprising because it occurs away from tectonic plate boundaries, where most volcanoes are found. These hotspots are thought to form above mantle plumes, narrow upwellings of hot rock that originate at Earth's core-mantle boundary almost 3,000 kilometres below the surface.
The study, published in Nature, found that sections of the track have no volcanic activity because the Australian continent is too thick to allow the hot rock in mantle plumes to rise close enough to the Earth's surface for it to melt and form magma.
The research found that the plume created volcanic activity only where Earth's solid outer layer, called the lithosphere, is thinner than 130 kilometres.
These new findings will help scientists to understand volcanism on other continents and from earlier periods in Earth's history, said co-author Dr Nick Rawlinson, now at the University of Aberdeen's School of Geosciences.
"Ultimately this new understanding may help us to reconstruct the past movements of continents from other hotspots," he said.
The giveaway that the continent is just thin enough for melting to begin, such as in northern New South Wales, is the formation of an unusual mineral called leucitite.
Leucitite is found in low-volume magmas that are rich in elements such as potassium, uranium and thorium, said co-author Professor Ian Campbell from the ANU Research School of Earth Sciences.
"Now that we know there is a direct relationship between the volume and chemical composition of magma and the thickness of the continent, we can go back and interpret the geological record better," Professor Campbell said.
The scientists have named the volcanic chain the Cosgrove hotspot track.
Dr Davies said the mantle plume that formed the Australian volcanoes is probably still in existence, under the sea a little to the northwest of Tasmania.
"There are observations of higher mantle temperatures and increased seismicity in this region," he said.
Dr. Rhodri Davies | EurekAlert!
Mountain glaciers shrinking across the West
23.10.2017 | University of Washington
Climate change weakens Walker circulation
20.10.2017 | MARUM - Zentrum für Marine Umweltwissenschaften an der Universität Bremen
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
23.10.2017 | Event News
17.10.2017 | Event News
10.10.2017 | Event News
23.10.2017 | Physics and Astronomy
23.10.2017 | Earth Sciences
23.10.2017 | Health and Medicine