Where even rock is weaker - Between 90 and 110 kilometers below ground, Earth’s hard shell – the lithosphere – meets the more pliable asthenosphere. The boundary between the two layers is no more than 11 kilometers thick, according to a new study.
Earth’s cool, rigid upper layer, known as the lithosphere, rides on top of its warmer, more pliable neighbor, the asthenosphere, as a series of massive plates. Plates continuously shift and break, triggering earthquakes, sparking volcanic eruptions, sculpting mountains and carving trenches under the sea.
But what, exactly, divides the lithosphere and the asthenosphere? In the latest issue of Nature, a trio of geophysicists from Brown University and the Massachusetts Institute of Technology publish research that sheds new light on the nature of the boundary between these rocky regions.
Lead author Catherine Rychert, a 26-year-old graduate student in Brown’s Department of Geological Sciences, found a sharp dividing line between the lithosphere and the asthenosphere, according to data culled from seismic sensors sprinkled across the northeastern United States and southeastern Canada. Rychert and colleagues discovered that sound waves recorded by the sensors slow considerably about 90 to 110 kilometers below ground – a sign that the rock is getting weaker and that the lithosphere is giving way to the asthenosphere. Within in a distance of a mere 11 kilometers – roughly 7 miles or less – the transition is complete.
Wendy Lawton | EurekAlert!
Climate change weakens Walker circulation
20.10.2017 | MARUM - Zentrum für Marine Umweltwissenschaften an der Universität Bremen
Shallow soils promote savannas in South America
20.10.2017 | Senckenberg Forschungsinstitut und Naturmuseen
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...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research