Sentences with phrase «seafloor hydrate»

The «methane bomb» idea refers to deep water seafloor hydrate deposits.

Their carbon - isotope ratio shows that all of a sudden there was a lot more light carbon - 12 — the kind that living organisms favor, the kind in seafloor hydrates — in the water around the forams.

«I would argue that there's zero evidence for that,» says Gerald Dickens, a leading expert on seafloor hydrates and their role in climate change.

Huge quantities of methane, the theories say, have escaped from seafloor hydrates at various times in the past, wreaking havoc.

Not exact matches

In many parts of the world, the seafloor contains natural gas trapped inside ice crystals called hydrates.

The Navy wanted to know if hydrates under the seafloor were interfering with acoustic signals picked up by an underwater hydrophone array used by the military to track Soviet subs.

Not the least of the challenges is that marine hydrate deposits are located in ocean mud up to a kilometer below the seafloor.

It used to be thought that the methane in hydrates was made the way oil is — that Earth's internal heat makes methane, the smallest hydrocarbon, by cracking bigger hydrocarbons at depths of more than a mile below the seafloor.

There is so much methane that, as it freezes instantaneously to form hydrate, it draws all the water out of the seafloor ooze and dries it out completely — and often there is methane left over, trapped as large bubbles in the porous hydrate.

The hydrate is extremely unstable; as it gets buried deeper by fresh sediment falling on the seafloor above, it warms enough to release its methane again.

Researchers have been studying this process in a concentrated effort 100 kilometers off the coast of Oregon, along a dumbbell - shaped promontory called Hydrate Ridge for the icy deposits that virtually pave the seafloor there.

That's why hydrates, like oil — and like fish — tend to be found along the world's coastlines, where the waters are rich in nutrients and plankton corpses fall like thick snow to the seafloor.

Then last summer at Hydrate Ridge they discovered something that they had never seen before: Fizzing chunks of hydrate, some the size of refrigerators, broke off the seafloor a kilometer deep and floated to the surface before disintegHydrate Ridge they discovered something that they had never seen before: Fizzing chunks of hydrate, some the size of refrigerators, broke off the seafloor a kilometer deep and floated to the surface before disinteghydrate, some the size of refrigerators, broke off the seafloor a kilometer deep and floated to the surface before disintegrating.

As it approaches the seafloor, it chills, and in many places it freezes, together with water in the mud, into solid methane hydrate (white).

Suess now attributes this buoyancy, not a typical hydrate characteristic, to large bubbles of gas that accumulate in the top layers of the seafloor ooze before freezing.

Of the many questions that cling to scenarios of methane - driven climate change, the biggest is this: Can methane from melting hydrates actually make it from the seafloor to the atmosphere?

In addition to methane hydrates, carbon - rich permafrost that is tens of thousands of years old — and found throughout the Arctic on land and in seafloor sediments — can produce methane once this material thaws in response to warming.

However, if the seafloor is already saturated with gas and the process takes place very quickly, the released gases make their way to the seafloor, without forming new hydrates,» says Dr. Karstens.

When dozens of meters of new sediment settle on the seafloor, the solid compounds dissociate at the base of the hydrate stability zone, while new hydrates can form at the upper end of the stability zone.

The numerical simulations of the seafloor also showed that the pockmarks in Nyegga are likely associated with this phenomenon because they are located right in the area of the largest gas hydrate dissociation event at the end of the Ice Age.

For example, data from this study has been used to examine the evolution of gas hydrate stability within the Eurasian Arctic over glacial timescales, exploring the development of massive mounds and methane blow - out craters that have been recently discovered on the Arctic seafloor.

If the pressure is too low or the temperature too high, the hydrates dissociate (break down), the methane is released and the gas can seep from the seafloor into the ocean.

Even where methane increases are observed at the ocean surface, scientists need better data to determine whether emissions come from hydrates or other seafloor sources.

Our results stress the importance of external climatic forcing of the dynamics of the seafloor, and the role of the rapid warming following the Younger Dryas in pacing the marine gas hydrate reservoir.

Boulder, Colo., USA: Cretaceous climate warming led to a significant methane release from the seafloor, indicating potential for similar destabilization of gas hydrates under modern global warming.

Based on pressure and temperature modelling, we show that the last deglaciation could have triggered dissociation of gas hydrates present in the region of the northern part of the Norwegian Channel, causing degassing of 0.26 MtCH4 / km2 at the seafloor.

Rich deposits of methane hydrate underlie much of the Arctic seafloor.

In time, the icy hydrate began collecting in bulging domes atop the seafloor.

As such, there is a diffusion gradient of dissolved CH4 between the top of gas hydrate and the seafloor.

The model showed that there should be a seasonal cycle in the behavior of the shallow - water hydrates just below the seafloor, with some additional hydrates forming while the water temperature is cooler and then melting when the water is warmer.

A search for gas venting on the Arctic seafloor focused on pingo - like - features (PLFs) on the Beaufort Sea Shelf because they may be a direct consequence of gas hydrate decomposition at depth.

It was developed by scientists at CAGE — Centre for Arctic Gas Hydrate Environment and Climate, and shows that seafloor off Western Svalbard was covered by a large ice sheet during the last glaciation.

Large amounts of methane are stored in seafloor sediments as gas hydrate, and as these melt the gas is released into the water column.

Figure 2: A piece of methane hydrate dredged from the seafloor.

For example, data from this study has been used to examine the evolution of gas hydrate stability within the Eurasian Arctic over glacial timescales, exploring the development of massive mounds and methane blow - out craters that have been recently discovered on the Arctic seafloor.

Methane hydrates that are on the edge of stabilization can be disturbed by global warming in two additional ways, temperature and pressure: Warming of the Earth's crust as heat penetrates sediments on the seafloor.

Most of Earth's gas hydrates occur at low saturations and in sediments at such great depths below the seafloor or onshore permafrost that they will barely be affected by warming over even 1000 yr.

What this exciting new research vessel will allow us to learn about seafloor spreading, earthquakes, magma flow, gas hydrate deposits, continental drift, and more, will expand scientific knowledge about the Earth and contribute to our ability as humans to withstand its extreme forces.

The expedition started from the well - established fact that an enormous amount of methane is frozen into a kind of ice known as methane hydrate, buried in seafloor sediments and containing perhaps twice as much carbon as all the world's fossil - fuel reserves combined.

MacDonald, I.R., L.C. Bender, M. Vardaro, B. Bernard, and J.M. Brooks, Thermal and visual time - series at a seafloor gas hydrate deposit on the Gulf of Mexico slope, Earth and Planetary Science Letters, 233 (1 - 2), 45 - 59, 2005.