Scientists have long held the belief that the fracturing of the Earth’s brittle outer shell into faults along the deep ocean’s mountainous landscape occurs only during long periods when no magma has intruded. Challenging this predominant theory, findings from a completed study show how differences in mid-ocean ridge magma-induced activity produce distinctly different types of ocean floor faulting. W. Roger Buck, Doherty Senior Research Scientist at the Lamont-Doherty Earth Observatory (LDEO), is one of a trio of scientists who developed these new models for faults seen at mid-ocean ridges where the Earth’s tectonic plates split apart and basaltic magma rises to form the oceanic crust that today covers two-thirds of the planet. The scientists’ work has culminated in the publishing of their findings in the April 7, 2005 issue of Nature.
Unlike faults on land, those formed along mid-ocean ridges are practically a dime a dozen. "The rate of fault generation across these ridges is a hundred times greater than on land," explains Buck. "And while land faults are easily eroded and often cut older faults in complex, hard-to-untangle ways, submarine faults break into newly formed crust and lithosphere and are little obscured by erosion. Recent observations show a huge range of fault types and sizes at ridges." These combined factors make mid-ocean ridges "the place to learn about how faults form and grow."
The team’s findings challenge the standard view that all faults at these ridges result from tectonic stretching of thin near-ridge lithosphere (the Earth’s brittle outer shell, where earthquakes are concentrated) in the absence of magma, hot molten rock from deep within the Earth. Among several recent observations that do not fit this standard model, two stand out: the first concerns where the faults form and the second deals with how far the faults slip. Faults formed at fast-spreading centers, like the East Pacific Rise, are tiny in comparison to faults that bound deep ocean hills at slow-spreading centers like the Mid-Atlantic Ridge. All ridge faults start off growing close to the ridge. Mid-Atlantic faults die only a short distance from where they are formed. In comparison, faults along the East Pacific Rise continue growing--although very slowly--much farther from the ridge axis. The new models show that these faults may form due to bending, not stretching, of the lithosphere.
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