Sentences with phrase «deep earthquakes»

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

Deep earthquakes do not define a descending slab; in fact, do not even occur in most places along the trenches.

Such deep earthquakes usually don't cause enough shaking on the surface to be hazardous, but scientifically they are of great interest.

«Seismologists puzzle over largest deep earthquake ever recorded.»

Download Cascadia Deep Earthquakes Cascadia Subduction Zone Earthquakes: A magnitude 9.0 earthquake scenario Read our new publication about the effects of a major subduction earthquake on communities along the Cascadia Subduction Zone, stretching from the Brooks Peninsula on Vancouver Island to Cape Mendocino in northern California.

Based on his graduate work at the University of Washington (UW), Seattle, the work published in Science reports that the potential magnitude of deep earthquakes in the central Puget Sound region is determined by just how deep they are.

The team also analyzed how deep the earthquakes occur underground and concluded that as quakes occur deeper, the rocks become stronger and the stress drop, or force behind the earthquakes, becomes more powerful.

First author Lingling Ye, a graduate student working with Lay at UC Santa Cruz, led the seismic analysis, which revealed that this was the largest deep earthquake ever recorded, with a seismic moment 30 percent larger than that of the next largest, a 1994 earthquake 637 kilometers beneath Bolivia.

The broader region is vulnerable to earthquakes from multiple sources, including deep earthquakes within the subducted Juan de Fuca plate, offshore megathrust earthquakes on Cascadia subduction zone and the shallow crustal earthquakes within the North American Plate.

Since his early research on deep earthquakes, Vedran Lekic has repeatedly developed new ways of analyzing and modeling seismic data, leading to improved understanding of Earth's large - scale inner strucutre.

It involved shear faulting with a fast rupture velocity of about 4 kilometers per second (about 9,000 miles per hour), more like a conventional earthquake near the surface than other deep earthquakes.

While deep earthquakes also get started in response to increasing stresses, the rocks there flow rather than break, except under special conditions.

It was Green's laboratory that first conducted a serendipitous series of experiments, in 1989, on the right kind of mantle rocks that give geologists insight into how deep earthquakes work.

«Common mechanism for shallow and deep earthquakes proposed.»

The result of that heating in shallow earthquakes is to initiate reactions like the ones that take place in deep earthquakes so they both end up lubricated in the same way.»

«This finding challenges the previous theory explaining deep earthquakes, and brings in new thoughts on the thermal and dynamic evolution of the subducting slab,» Wei told LiveScience's OurAmazingPlanet.

This suggests deep earthquakes are likely more efficient in dissipating stress than are shallow ones, the investigators said.

As far as seismologists now understand, all but the very deepest earthquakes (deeper than 600 km) occur on faults.

In Puget Sound, for example, there is an 84 % chance of a magnitude 6.5 or greater deep earthquake striking within 50 years.

More information: CREW has produced a 28 - page report that summarizes the threat from deep earthquakes and includes pre-quake efforts that limited damage during the Nisqually event.

Damaging deep earthquakes occur every ten to 30 years in the Puget Sound area and less frequently elsewhere in Cascadia.

A prior deep earthquake, in Bolivia in 1994, was the same magnitude, but released less energy.

Wiens specializes in seismology and geophysics and has done extensive research on large deep earthquakes in the Pacific Ocean.

Instead, deep earthquakes in this region occur at depths of 500 to 650 km and are concentrated into two zones: one that runs beneath the Peru - Brazil border and another that extends from central Bolivia to central Argentina.

Deep earthquakes occur at depths of 30 to 50 miles (80 to 45 km) beneath much of Oregon and Washington, and at depths of about 25 miles (40 km) beneath northwestern California.

The researchers attributed the dramatic differences between these two deep earthquakes to differences in the age and temperature of the subducted slab.

The rupture extended about 180 kilometers, by far the longest rupture for any deep earthquake recorded, Lay said.

Because such shifts in olivine change the structure of earth's subducted lithosphere, the new phase transition mechanism could help explain the origins of some deep earthquakes.

Deep earthquakes occur in these regions.

Seismologists still have much to learn about the mechanism that causes the deepest earthquakes.

Download CREW Shallow Earthquakes Scenarios Cascadia Deep Earthquakes Deep earthquakes pose a serious risk to Cascadia.

Deep earthquakes, also called intraplate quakes, take place within the oceanic Juan de Fuca plate (beneath Oregon and Washington) and the Gorda plate (beneath northwestern California) as they subduct beneath the North America plate.

Nisqually, Washington (2001): The M6.8 earthquake that struck the Puget Sound area on Feb. 28, 2001 was a deep earthquake.

In contrast to more common shallow and deep earthquakes, a subduction zone quake will generate a destructive tsunami, a series of waves up to 30 feet (10 m) high that will hit the Cascadia coast and travel across the Pacific Ocean toward Alaska, Hawaii and Asia.