Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

20-year study yields precise model of tectonic-plate movements

24.03.2010
A new model of the Earth, 20 years in the making, describes a dynamic three-dimensional puzzle of planetary proportions.

Created by University of Wisconsin-Madison geophysicist Chuck DeMets and longtime collaborators Richard Gordon of Rice University and Donald Argus of NASA's Jet Propulsion Laboratory, the model offers a precise description of the relative movements of 25 interlocking tectonic plates that account for 97 percent of the Earth's surface.

"This model can be used to predict the movement of one plate relative to any other plate on the Earth's surface," explains DeMets. "Plate tectonics describes almost everything about how the Earth's surface moves and deforms, but it's remarkably simple in a mathematical way."

Tectonic plates are in constant motion, sliding past one another as they float atop the planet's molten interior. The collisions and shifts can create mountain ranges or cause earthquakes like the ones that struck Haiti and Chile this year.

"We live on a dynamic planet, and it's important to understand how the surface of the planet changes," Gordon says. "The frequency and magnitude of earthquakes depend upon how the tectonic plates move. Understanding how plates move can help us understand surface processes like mountain-building and subsurface processes like mantle convection."

The new model, dubbed MORVEL for "mid-ocean ridge velocities," is described in an extensive article available online and slated for the April issue of Geophysical Journal International. The work builds on the collaborators' 1990 paper on tectonic plate velocities that has been cited more than 2,000 times by other scientists. During the past 20 years, the researchers have incorporated more and higher-quality data to improve the model's resolution and precision.

About three-quarters of MORVEL's data come from Earth's mid-ocean ridges, the undersea boundaries between tectonic plates. At these ridges, new crust forms constantly as magma wells up from beneath the planet's surface and forces the plates apart.

To judge how fast the plates are spreading, the team analyzed nearly 2,000 magnetic profiles of the crust formed at mid-ocean ridges in all the major ocean basins. The Earth's magnetic field changes polarity at irregular intervals — most recently about 780,000 years ago — and each time leaves a magnetic mark in the crust akin to a tree ring. Measuring the distances between the marks tells them how quickly new crust is being formed. Most plate boundaries are currently moving at rates of 15 to 200 millimeters per year, DeMets says.

MORVEL also allows scientists to predict future plate movements and identify places where movements have changed over time, areas that are useful for studying the underlying forces that control plate movements.

"Along the boundaries where plates meet there are lots of active faults. It's useful to know how quickly the plates are slipping across those faults because it gives you some feeling about how often large earthquakes might occur," DeMets says. "The direction of movement across the faults gives some indication of whether plates are moving toward one another, which gives rise to one kind of faulting and seismic hazard, or slightly away from each other, which gives rise to another kind of faulting and a different type of seismic hazard."

The model is accessible online at http://www.geology.wisc.edu/~chuck/MORVEL/, a site that can be used to show present-day plate movements by choosing any location in the world.

The work was supported by the National Science Foundation and NASA.

Chuck DeMets | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Earth Sciences:

nachricht Fossil coral reefs show sea level rose in bursts during last warming
19.10.2017 | Rice University

nachricht NASA finds newly formed tropical storm lan over open waters
17.10.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

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...

Im Focus: Breaking: the first light from two neutron stars merging

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....

Im Focus: Smart sensors for efficient processes

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...

Im Focus: Cold molecules on collision course

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...

Im Focus: Shrinking the proton again!

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Electrode materials from the microwave oven

19.10.2017 | Materials Sciences

New material for digital memories of the future

19.10.2017 | Materials Sciences

Physics boosts artificial intelligence methods

19.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>