Sentences with phrase «aleutian subduction»

An apocalyptically - worded story in the latest issue of the New Yorker detailed the devastation that might result from a high - magnitude earthquake along the Cascadia subduction zone, a fault line that runs from Cape Mendocino, Calif., to Vancouver Island, Canada.

The water the receded into the present day oceans we now have because of the subduction due to the excess weight of the water on caverns from which the water burst forth from.

The first is that fossils are formed only under a small set of very special circumstances, and that fossils formed are often obliterated by a variety of well - verified mechanisms, including subduction of continental plates under the earth's crust, the fate of most pre-Cambrian fossils.

It's actually older than any visible hills due to geologic activity, e.g. erosion, uplift, subduction, etc..

June 17, 2013 — A new subduction zone forming off the coast of Portugal heralds the beginning of a cycle that will see the Atlantic Ocean close as continental Europe moves closer to America.

There's no such disproportion in power as it is with goverment and its citizens, so what about subduction to goverment?

But here the sliver of continental crust lies on the Pacific plate, and it is the Australian plate that is being destroyed through subduction.

SASMEX tracks seismicity in the subduction zone through 97 seismic monitoring stations.

SASMEX's main focus is on earthquakes originating in the subduction zone off the southern coast of Mexico, where the Cocos tectonic plate subducts below the North American Plate.

The Tehuantepec earthquake originated offshore in the subduction zone, while the Morelos earthquake was an example of in - slab seismicity.

The relatively low - density continental crust of the North Island, which sits on the Australian plate, is forcing the dense oceanic crust on the Pacific plate beneath it in a process called subduction.

These initial results provide fundamental insights into the behavior of rare, very large earthquakes that may aid in preparation and early warning efforts for future tsunamis following subduction zone earthquakes.

This happens when one tectonic plate is pushed down underneath another — a process called subduction.

«[Subduction] is essentially a one - way process and irreversible,» he says.

However, the seismic potential of crustal faults within the forearc of the northern Cascadia subduction zone in British Columbia has remained elusive.

To get such a high mountain chain in a subduction zone setting is unusual which adds to the importance of trying to figure out when and how it happened.

What's more, when the minerals return to the surface in the forearcs of subduction zones, they can break down over millions of years, releasing gases back to atmosphere once again.

They simulated earthquakes with magnitudes between 9.0 and 9.6 originating at different locations along the Aleutian - Alaska subduction zone, a 3,400 - kilometer (2,113 - mile) long ocean trench stretching along the southern coast of Alaska and the Aleutian Islands where the Pacific tectonic plate is slipping under the North American plate.

Baldwin's team discovered an area in Papua New Guinea that had been through just such a subduction and exhumation cycle.

Combining the 19th - century records of such effects with modern earthquake models helped Beauducel and Feuillet pin down both the quake's magnitude and the location of the fault rupture, the spot where the subduction zone tore apart.

Given that the last big quake was 312 years ago, one might argue that a very bad day on the Cascadia Subduction Zone is ominously overdue.

Cascadia, however, is classified as the quietest subduction zone in the world.

Professor McNeill explained that the North Sumatran subduction margin has an unusual structure and morphology that is likely influenced by the properties of the sediments and rocks forming the margin.

Three basic forces are believed to drive oceanic plate movement: plates are «pushed» away from mid-ocean ridges as new sea floor forms; plates are «pulled» as the oldest parts of the plate dive back into the earth at subduction zones; and convection within the asthenosphere helps ferry the plates along.

«The Boxing Day earthquake of 2004 and the Japan Tohoku - oki earthquake in 2011 both ruptured to much shallower depths than expected, producing very large earthquakes and tsunami, and prompting a re-evaluation of earthquake slip potential and of the properties of shallow subduction faults,» Professor McNeill continued.

«We have an excellent team onboard and we hope the results will help us understand what controls the size of the very largest earthquakes on Earth, particularly following the enormous numbers of casualties due to subduction earthquakes and tsunamis in the last 10 - 15 years.

The pressure difference could be caused by hot, partially molten rock piled up beneath mid-ocean ridges or beneath the cooling plates diving into the earth at subduction zones, the authors write.

«Although our understanding of this margin's structure and development has increased enormously since 2004 due to marine geophysical data collection, as yet very little is known of the properties of the materials that make up this subduction zone,» she continued.

But we do not know how the sediments change as they become physically and chemically altered as the sediment section builds up to 4 - 5 km thickness before reaching the subduction zone.

«The only way to explain the subsidence of the islands is to have a rupture... in the very deep part of the subduction zone, between 40 and 60 km (25 to 40 miles) depth,» Feuillet said.

Now scientists are calling attention to a dangerous area on the opposite side of the Ring of Fire, the Cascadia Subduction Zone, a fault that runs parallel to the Pacific coast of North America, from northern California to Vancouver Island.

A magnitude - 9.0 earthquake would likely give way along the whole north - south extent of the subduction zone, but it's not well known how far east the shake - producing area would extend, approaching the area beneath major cities such as Seattle and Portland.

Therefore developing a better understanding of earthquake and tsunami behavior and potential is a priority for local communities, for the wider Indian Ocean, and for related subduction zones.»

One hint of weak coupling at a subduction zone is the presence of serpentinite — a mineral formed when seawater carried down by a descending plate reacts with mantle rock.

Many of the islands sit above a subduction zone, where two plates meet and one slides haltingly under the other, down into the Earth's mantle.

«Measuring the strength of olivine is critical to understanding how strong tectonic plates are, which, in turn, matters to how plates break and create subduction zones like those along the Cascadia plate, which runs down the west coast of Canada to the west coast of the United States,» said Warren, a geologist in the College of Earth, Ocean, and Environment.

In the early 1980s, two Caltech geophysicists, Tom Heaton and Hiroo Kanamori, compared Cascadia to active quake - prone subduction zones along the coasts of Chile and Alaska and to the Nankai Trough off the coast of Japan.

Exactly the same is true of the Cascadia subduction zone — an almost identical geologic threat off the west coast of North America.

«This ocean drilling expedition will for the first time drill scientific boreholes within the sediments entering this subduction zone, including the layer of sediment that eventually develops into the earthquake - generating fault,» Professor Henstock explained.

Scientists have long wondered what accounts for that precipitous dive, and why the massive earthquakes that generate long - ranging tsunamis at other subduction zones have not been recorded in the trench.

Here we are not dealing with large volcanic eruptions of the size of Pinatubo of Mount St. Helens, here we are talking about extreme events: The Toba caldera in the Sumatra subduction zone in Indonesia originated from one of the largest volcanic eruption in recent Earth history, about 74,000 years ago.

On the Pacific Coast, this area sits along the subduction zone known as the Cascadia plate, which runs down the west coast of Canada to the west coast of the United States.

The Earth's lithosphere is divided into several plates that are in constant motion, and today's geologists have a good understanding of what drives these plate movements: heavier ocean plates are submerged beneath lighter continental plates along what are known as subduction zones.

Events of this magnitude normally occur in a subduction zone, where one tectonic plate slides beneath another.

The simulations show that mantle plumes and the weaknesses they create could have actually initiated the first subduction zones.

In 1964 a region of this same tectonic clash, called the Alaska — Aleutian Subduction Zone, produced the magnitude 9.2 «Good Friday» earthquake, the second - strongest quake ever recorded.

«Water acts as a lubricant and is an absolute necessity in the initiation of a self - sustaining subduction,» says Gerya.

But just as in the past, earth scientists still do not understand what triggered plate tectonics in the first place, nor how the first subduction zone was formed.

The island nation sits atop an active subduction zone where the Pacific Plate slips below the Australian Plate.

Most earthquakes are said to occur at subduction zones or along faults in tectonic plates.