The tectonic plate that dominates the Pacific "Ring of Fire" is not as rigid as many scientists assume
© Credit: Corné Kreemer and Richard Gordon
A map produced by scientists at the University of Nevada, Reno, and Rice University shows predicted velocities for sectors of the Pacific tectonic plate relative to points near the Pacific-Antarctic ridge, which lies in the South Pacific ocean. The researchers show the Pacific plate is contracting as younger sections of the lithosphere cool.
, according to researchers at Rice University and the University of Nevada.
Rice geophysicist Richard Gordon and his colleague, Corné Kreemer, an associate professor at the University of Nevada, Reno, have determined that cooling of the lithosphere - the outermost layer of Earth - makes some sections of the Pacific plate contract horizontally at faster rates than others and cause the plate to deform.
Gordon said the effect detailed this month in Geology
is most pronounced in the youngest parts of the lithosphere - about 2 million years old or less - that make up some the Pacific Ocean's floor. They predict the rate of contraction to be 10 times faster than older parts of the plate that were created about 20 million years ago and 80 times faster than very old parts of the plate that were created about 160 million years ago.
The tectonic plates
that cover Earth's surface, including both land and seafloor, are in constant motion; they imperceptibly surf the viscous mantle below. Over time, the plates scrape against and collide into each other, forming mountains, trenches and other geological features.
On the local scale, these movements cover only inches per year and are hard to see. The same goes for deformations of the type described in the new paper, but when summed over an area the size of the Pacific plate, they become statistically significant, Gordon said.
The new calculations showed the Pacific plate is pulling away from the North American plate a little more - approximately 2 millimeters a year - than the rigid-plate theory would account for, he said. Overall, the plate is moving northwest about 50 millimeters a year.
"The central assumption in plate tectonics
is that the plates are rigid, but the studies that my colleagues and I have been doing for the past few decades show that this central assumption is merely an approximation - that is, the plates are not rigid," Gordon said. "Our latest contribution is to specify or predict the nature and rate of deformation over the entire Pacific plate."
© Credit: Jeff Fitlow/Rice University
Rice University geophysicist Richard Gordon led a study that determined the Pacific tectonic plate is not as rigid as scientists have assumed.
There are other important factors to consider when studying tectonic plate movements, to increase our understanding of the subsequent seismic and volcanic activity, and also the formation of sinkholes (all of which are increasing at an alarming rate!), such as:
1. The slowdown of the Earth's rotation - causing mechanical stress on the crust.
2. Crustal slippage - the difference in rotation between the crust and mantle.
3. Reduction of the surface/core electric field.
These factors, the Electric Universe theory, and much more are fully explained in Earth Changes and the Human-Cosmic Connection.
It is looking increasingly likely that electrical discharges may be causing recent strange phenomena, such as these glowing lights over the 'ring of fire'
perhaps caused by the ignition of leaking methane
which may also be contributing to the discovery of thousands of dead fish
which is becoming more common and unusual whale behaviour
. 'Signs of the times' indeed!