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!
Hidden river once flowed beneath Antarctic ice
22.08.2017 | Rice University
Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter
17.08.2017 | Swansea University
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
23.08.2017 | Life Sciences
23.08.2017 | Life Sciences
23.08.2017 | Physics and Astronomy