Sentences with phrase «subducted at»

The warm Atlantic water was saltier, and therefore heavier and subducted at depth and reached to the bottom, actually heating up beneath a lid of ice and melt water, that prevented the release of heat to the atmosphere.

Since we know that Earth's atmosphere first carried measurable quantities of oxygen around 2.45 billion years ago, the crust must have formed and been subducted at least this long ago, Cabral reasons (Nature, DOI: 10.1038 / nature12020).

It's a block of thick crust that doesn't subduct easily, rather it subducts at a shallow angle,» said Mann.

The Caribbean plate in the north is subducting at a slower rate than the Nazca plate in the south, where seismic activity is greater.

Using tomographic data, the authors inferred that the Caribbean plate crust to the north is subducting at a very shallow angle and producing relatively little deep seismicity.

As the model helps explain, a volcano can form inland if the slab subducts at a shallower angle, and a hole in the shallow slab allows for a special type of magma to form by melting of the crust.

Not exact matches

One by the subducting pacific plate and the other by India colliding with the Asian plate at measuarable rates.

These plates move slowly, relative to one another, and, at convergent plate boundaries, one plate can be pushed underneath (i.e., subducted) the other.

They looked to compare the density of subducting slabs at that time with the density of the surrounding mantle, the difference of which would determine how far slabs would have sunk.

The shallow tremors had similar migration properties to deep low - frequency tremors that occur at the deep subducting plate interface, and that they also occurred synchronized in time and space with shallow very - low - frequency tremors that also thought to be triggered by slow slip events.

Using GPS, InSAR, gravity, seismic reflection, and geological data, Marcos Moreno and colleagues from GFZ as well as Chile show that the 2016 earthquake occurred at the deep boundary of a persistent asperity on the interface between the subducting Nazca and overriding South American plates, where both plates are coupled and not sliding past each other in spite of the high convergence velocity of 68 mm / year.

«Eastern Australia was drifting over a subducted plate graveyard, giving it a sinking feeling,» said co-author Dr Kara Matthews, a former PhD candidate at the University now at the University of Oxford.

At subduction zones such as these, an oceanic tectonic plate sinks (subducts) into the Earth's interior, the mantle.

On the hot young Earth, the outer layer was too weak and soft for plate tectonics to operate until the upper mantle cooled enough to allow sections of crust to slip under each other, or subduct, at collision zones some 3.2 to 2.5 billion years ago.

More perplexing still, seismic studies have shown no evidence that ocean crust is being subducted — thrust down into the hot mantle underlying the trench — which is the process that results in quakes at other deep - sea trenches.

At certain subduction zones, such as those in Cascadia, Sumatra and eastern Alaska, a thick sediment layer overlies the subducting oceanic plate.

Hydration reactions along the subducting plate are thought to carry water deep into the Earth, and dehydration reactions at greater depths release fluids into the overlying mantle that promote melting and volcanism.

Now a team of researchers, led by Teh - Ru Alex Song of the Carnegie Institution's Department of Terrestrial Magnetism, has found that an anomalous layer at the top of a subducting plate coincides with the locations of slow earthquakes and non-volcanic tremors.

These great quakes often take place at subducting tectonic plate boundaries, where one plate thrusts beneath another plate, as is the case off the coast of Chile and the U.S. Pacific Northwest.

We used local observations recorded within 100 to 150 miles to map the structures at the top of the subducting plate.»

Song and team believe that it may be subducted oceanic crust at unusually high levels of water saturation.

In subtropical regions, its source waters are typically surface waters at higher latitudes that have subducted and moved equatorward.

The CO2 tectonic source grew from 60 to 50 Myr BP as India subducted carbonate - rich ocean crust while moving through the present Indian Ocean prior to its collision with Asia about 50 Myr BP [8], causing atmospheric CO2 to reach levels of the order of 1000 ppm at 50 Myr BP [9].

However, it must be borne in mind that the MOC can also include shallower, wind - driven overturning cells such as occur in the upper ocean in the tropics and subtropics, in which warm (light) waters moving poleward are transformed to slightly denser waters and subducted equatorward at deeper levels.