Sentences with phrase «upper mantle»

Sun, X., Wiens, D., Nyblade, A., Anandakrishnan, S., Aster, R., Huerta, A., Wilson, T., Kanao, M., An, M., Crust and upper mantle structure beneath Antarctica from seismic ambient noise study, Eos Trans.

Currently there is a continent - wide project mapping the Australian upper mantle using the same electromagnetic technique, and the researchers believe applying this data to their new model will bring improved understanding of volcanic and earthquake activity along the southeastern and eastern coast of Australia.

That's because the rising magma that produced the lavas probably mixed with upper mantle rocks, which have been contaminated with isotopically heavy surface water that got dragged down by subducting slabs of tectonic plates.

It turned out that lower mantle carbonates should be iron - rich, unlike upper mantle carbonates (see figure 2 below).

Sun, Xinlei, Wiens, D., Anandakrishnan, S., Aster, R., Huerta, A., Nyblade, A., Wilson, T., An, M., Kanao, M., Crust and upper mantle shear wave structure of Antarctica from seismic ambient noise, Eos Trans.

«But low - and medium - intensity tremors occur with a certain frequency in Brazil, and these can have drastic consequences depending on where they happen,» said the principal investigator for the research project «Pantanal - Chaco - Paraná basins (PCPB): crust and upper mantle seismic structure and evolution,» supported by the São Paulo Research Foundation (FAPESP).

Looking at the entire upper mantle, the scientists found that the most powerful process causing rocks to flow happens in the upper part of the lithosphere as new sea floor is created at a mid-ocean ridge.

Senior author Barbara Romanowicz, a UC Berkeley professor of earth and planetary science, noted that the connections between the lower - mantle plumes and the volcanic hotspots are not direct because the tops of the plumes spread out like the delta of a river as they merge with the less viscous upper mantle rock.

Williams explained: «The ratio of helium - 3 to helium - 4 in mid-ocean ridge basalts are globally characterized by a narrow range of small values and are thought to sample a relatively homogenous upper mantle.

The three ancient Yellowstone supervolcano eruptions were only the latest in a series of more than 140 as the North American plate of Earth's crust and upper mantle moved southwest over the Yellowstone hotspot, starting 17 million years ago at the Oregon - Idaho - Nevada border.

Hernandez, S., Wiens, D., Anandakrishnan, S., Aster, R., Huerta, A., Nyblade, A., Wilson, T., Seismic anisotropy of the Antarctic upper mantle from shear wave splitting analysis of POLENET and AGAP seismograms, Eos Trans.

Sun, X., Wiens, D., Nyblade, A., Anandakrishnan, S., Aster, R., Chaput, J., Huerta, A., Wilson, T., Three dimensional crust and upper mantle velocity structure of Antarctica from seismic noise correlation, Eos Trans.

Previous research had shown that upper mantle carbonates are magnesium - rich and iron - poor.

Temperature variations in the upper mantle drive mantle convection.

The lithosphere is the rigid outer part of Earth, consisting of the crust and upper mantle, while the asthenosphere lies just below the lithosphere and is hotter and more fluid than the lithosphere.

Thanks to Swarm's precise measurements along with those from Champ — a mission that ended in 2010 after measuring Earth's gravity and magnetic fields for more than 10 years — scientists have not only been able to find the magnetic field generated by ocean tides but, remarkably, they have used this new information to image the electrical nature of Earth's upper mantle 250 km below the ocean floor.

There is far more mechanical, chemical, and thermal interaction between the craton of billions of years in age and its surrounding in the upper mantle of Earth than previously thought.

Roger Haagmans, ESA's Swarm mission scientist, explained, «It's astonishing that the team has been able to use just two years» worth of measurements from Swarm to determine the magnetic tidal effect from the ocean and to see how conductivity changes in the lithosphere and upper mantle.

On the Earth, the lithosphere includes the crust and the uppermost layer of the mantle (the upper mantle or lower lithosphere) which is joined to the crust.

The researchers propose that the reason the Central Anatolian (Turkish) Plateau has risen by as much as one kilometre over the past 10 million years is because the planet's crust and upper mantle — the lithosphere — has thickened and dripped below the region.

Professor Damon Teagle, from Ocean and Earth Science at the University of Southampton and a veteran of numerous scientific ocean drilling expeditions, said: «It is very exciting for IODP to be using a British ship and new technologies to investigate the strange reactions that occur when seawater meets rocks of the upper mantle.

The lithosphere, Earth's solid outer shell, consists of the upper mantle and the crust that includes the surface.

Tharimena's team looked at waves that bounced off boundaries between different layers in Earth's upper mantle and other waves that ricocheted off the underside of the planet's surface before ultimately reaching the same seismometer.

The gravitational pull of the sun and moon deforms the Earth's crust and upper mantle, creating bulges and dips in the planet called Earth tides.

Others reflect off a layer of melt in the upper mantle or bounce off the underside of Earth's surface.

Published in the journal Science today, the research describes a new model of Earth's movement in the upper crust through to upper mantle (400 km below the surface), allowing predictions at a much smaller scale than previously possible.

The Rutgers - led study focused on New England, where scientists had previously documented an area of great warmth (hundreds of degrees Celsius warmer than neighboring areas) in the Earth's upper mantle.

«We're interested in what happens at the interface between tectonic plates — thick, solid parts that cover our planet — and material in the upper mantle beneath the plates,» Levin said.

«We think the upper mantle is rich in a mineral called olivine, but we don't see much olivine in the basin.

In the months before an October 2011 eruption, magma from the upper mantle accumulated in a layer of oceanic crust 6 to 10 miles below sea level.

In fact, lava emerging from hotspot volcanoes is known to differ chemically and isotopically from lava from other volcanoes, such as those erupting at subduction zones where Earth's crust dives into the upper mantle.

Earth's upper mantle, which makes up much of the lithosphere, is a relatively simple mix, consisting primarily of two rock types, olivine and pyroxene.

Everything on the surface of the Earth rests on massive tectonic plates that resemble a jelly sandwich, with two rigid pieces — the upper crust and the upper mantle — enclosing a gooey middle layer of very hot rocks, which is the lower crust.

Although the heat of the upper mantle might help the olivine or pyroxene crystals within the rocks grow larger again, or «heal,» the two rock types are competing for space: Each is actually inhibited in its growth by the other's presence.

Ke Jia of Beijing University and colleagues explore the relationship of the two quakes with a statistical analysis of aftershocks in the region as well as the evolution of shear stress in the lower crust and upper mantle in the broader quake region.

Deep earthquakes occur in the transition zone between the upper mantle and lower mantle, from 400 to 700 kilometers below the surface.

Some believed they came from no deeper than the upper mantle of the Earth, while others argued that they originated much further down.

Hartmann recognized that such a cataclysmic impact could account for the moon's superficial similarity to Earth if it blasted only the planet's crust and upper mantle into space and left the iron core intact.

The group studied how olivine, the most abundant mineral in the earth's upper mantle, transforms under pressure to become a more dense form called spinel.

This is leading to a much better understanding of many facets of our planet — from the boundary between Earth's crust and upper mantle to the density of the upper atmosphere.

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.

Volcanoes are openings, or vents, in Earth's crust through which magma — formed when the planet's upper mantle and lower crust melts — and gases are discharged.

Scientists seeking to understand the forces at work beneath the surface of Earth have used seismic waves to detect previously unknown «fingers» of heat, some of them thousands of miles long, in Earth's upper mantle.

But some hotspot volcano chains are not easily explained by this simple model, a fact which suggests there are more complex interactions between these hot plumes and the upper mantle.

Once a period of mountain - building ends, these fluid layers (Earth's upper mantle and Titan's liquid ocean) allow the crust to relax, like a person settling into a waterbed.

Titan's icy crust sits atop a deep ocean of liquid water that probably acts much like Earth's upper mantle — the layer of hot, high - pressure rock below the crust that can slowly flow and deform over time.

Existing model calculations, however, were based on a consideration of the ice cap and considered the effect of the lithosphere, i.e. Earth's crust and upper mantle, too simplistic and primarily mechanical: the ice presses the crust down due to its weight.

Through convection — slow movements of material in the upper mantle — the material was eventually mixed around and carried to the area of the mid-ocean ridges and transported back to the surface in the lavas that make up MORBs.

This means that slabs are weak enough to deform internally in the upper mantle over time.»

«To do that, we need to understand the mechanical behavior of olivine, which is the most common mineral in the upper mantle of Earth.»