Sentences with phrase «seismic wave velocities»

When they compared oceanic hotspots with high levels of He - 3 / 4 to seismic wave velocities, they found that these represent the hottest hotspots, with seismic waves that move more slowly than they do in cooler areas.

Not exact matches

Inspired by a 2012 paper that proposed a correlation between such hotspots and the velocity of seismic waves moving through Earth's interior, UC Santa Barbara geochemist Matthew Jackson teamed with the authors of the original paper — Thorsten Becker of the University of Texas at Austin and Jasper Konter of the University of Hawaii — to show that only the hottest hotspots with the slowest wave velocity draw from the primitive reservoir formed early in the planet's history.

Researchers calculated temperatures at the bottom of the crust, which varies in thickness, by measuring the velocity of seismic waves that travel near the interface between the lower crust and uppermost mantle.

The mineral has a unique layered structure that causes seismic waves to change velocity depending on their direction of travel — just as in the D» layer.

The relatively small rock bodies are termed «ultra-low velocity zones» because seismic waves greatly slow down as they pass through them.

Because we can not sample the deep Earth, we must deduce its composition either by looking at the clues hidden in igneous and metamorphic rocks, or by examining proxies for composition and structure such as the three - dimensional variation of the velocity of seismic waves produced by earthquakes and sampled by networks of seismometers on the surface.

Led by Carnegie's Ho - kwang «Dave» Mao, the research team believes that as much as 300 million tons of water could be carried down into Earth's interior every year and generate deep, massive reservoirs of iron dioxide, which could be the source of the ultralow velocity zones that slow down seismic waves at the core - mantle boundary.

During a four - year period, the researchers used sensors to measure relative changes in the velocity of seismic waves moving through the volcano over time.

These seismic measurements enabled scientists to visualize these ultralow velocity zones in some regions along the core - mantle boundary, by observing the slowing down of seismic waves passing through them.

«Where these two crustal blocks came into contact, there would have been tremendous deformation that aligned the mineral grains in the rocks and changed the propagation velocities of the seismic waves,» Fischer said.

Led by Geophysical Laboratory's Ho - kwang «Dave» Mao, the research team believes that as much as 300 million tons of water could be carried down into Earth's interior every year and generate deep, massive reservoirs of iron dioxide, which could be the source of the ultralow velocity zones that slow down seismic waves at the core - mantle boundary.

The scans create images of seismic - wave velocity, which is largely controlled by temperature.