Sentences with phrase «ice shelves»

Other groups have drilled through Antarctic ice shelves before, he said, «but nobody looked up.»

Time - lapse visualizations of temperature, precipitation, receding sea ice, and collapsing ice shelves create a vivid experience of the natural pulses of the planet and the shifts brought on by climate change.

«That's going to be more effective in breaking these ice shelves apart.»

Such rapid disintegration has never been observed before, and it suggests the ice shelves were weakened by warm temperatures.

«When we included projected Antarctic wind shifts in a detailed global ocean model, we found water up to 4 °C warmer than current temperatures rose up to meet the base of the Antarctic ice shelves,» said lead author Dr Paul Spence from the ARC Centre of Excellence for Climate System Science (ARCCSS).

What's more, so did two smaller ice shelves elsewhere on the peninsula.

Unexpectedly, this more detailed approach suggests changes in Antarctic coastal winds due to climate change and their impact on coastal currents could be even more important on melting of the ice shelves than the broader warming of the ocean.

Changes to Antarctic winds have already been linked to southern Australia's drying climate but now it appears they may also have a profound impact on warming ocean temperatures under the ice shelves along the coastline of West and East Antarctic.

The ice shelves that fringe the land - based ice hold back the flow of inland ice to the ocean.

CLIMATE CALAMITIES As ice shelves on the Southern Antarctic Peninsula weaken, glaciers flow faster into the sea.

«If protective ice shelves were suddenly lost in the vast areas around the Antarctic margin where reverse - sloping bedrock (where the bed on which the ice sheet sits deepens toward the continental interior, rather than toward the ocean) is more than 1,000 meters deep, exposed grounding line ice cliffs would quickly succumb to structural failure as is happening in the few places where such conditions exist today,» the researchers point out.

However, it is often overlooked that the major ice shelves in the Ross and Weddell Seas and the many smaller shelves and ice tongues buttressing outlet glaciers are also vulnerable to atmospheric warming.»

Some large chunks of ice have broken off Antarctica's ice shelves in recent years, although most researchers don't foresee runaway melting there.

The work has revealed previously unknown undersea channels, through which warm water might flow toward fragile ice shelves.

Melting of ice shelves does not directly contribute to sea - level rise, but instead they hold back water frozen in the larger ice sheet that will cause sea levels to rise.

Warm currents can melt the floating ice shelves that hold back ice on land.

Within two years, scientists from the Woods Hole Oceanographic Institution and the University of Maryland will release self - guided robots to visit the hydrothermal vents deep beneath the Arctic ice shelves for the first time.

«It was the biggest collapse of its kind up to that point, and it served to demonstrate how ice shelves regulate the movement of ice from the interior of the ice sheet to the ocean.»

One response to this warming, scientists say, is the retreat of five ice shelves, including Larsen B. «Since [1998], warming on the peninsula has continued and we watched as piece - by - piece Larsen B has retreated,» David Vaughan of the British Antarctic Survey says.

Scambos's group predicted the final Larsen B collapse using a model that looks at how much meltwater has pooled on the surface of the ice, and he now hopes to apply the model to bigger Antarctic ice shelves.

All told, if the eastern and western Antarctic ice shelves were to melt completely, they would raise sea levels by as much as 230 feet (70 meters); the collapse of smaller shelves like Larsen B has sped up the flow of glaciers behind them into the sea, contributing to the creeping up of high tide levels around the world.

For decades beforehand, researchers had debated the extent to which ice shelves buttress glaciers on land — acting like corks that slow the land ice's inevitable march to the sea.

The Larsen A and B ice shelves, which were situated further north on the Antarctic Peninsula, collapsed in 1995 and 2002, respectively.

«Loss of ice shelves surrounding the Antarctic continent could have a major effect on the rate of ice flow off the continent,» Scambos notes.

Floating ice shelves mark the outermost edges of an ice sheet and line nearly half the Antarctic coastline.

But scientists increasingly attribute much of the observed grounding line retreat — particularly in West Antarctica — to the influence of warmer ocean water seeping beneath the ice shelves and lapping against the bases of glaciers, melting the ice from the bottom up.

Researchers report online March 26 in Science that several West Antarctic ice shelves are now on pace to disappear completely within 100 years.

«For the first time, we can set a baseline on what lives under ice shelves,» she says.

As a rule of thumb, she explains, the ice tends to break where it is thinner than 200 metres; in reality, however, there are also many ice shelves that are even thinner.

A better understanding of how and why the Larsen C crack expanded so quickly could help scientists better predict the future of all Antarctic ice shelves, says Richard Alley, a glaciologist at Penn State.

The researchers discovered that Antarctic ice shelves shrank on average 25 cubic kilometers per year from 1994 to 2003.

BREAK UP Last year a crack stretching tens of kilometers rapidly spread across Larsen C, shown here in 2009, one of the largest ice shelves in Antarctica.

Massive ice shelves — Antarctica's largest is bigger than California — get shoved off and float atop the ocean.

«Today, the Pine Island and Thwaites glaciers are grounded in a very precarious position, and major retreat may already be happening, caused primarily by warm waters melting from below the ice shelves that jut out from each glacier into the sea,» said Matthew Wise of Cambridge's Scott Polar Research Institute, and the study's first author.

Their instruments are zeroed in on the Amundsen Sea Embayment, a vast region rich in volcanoes, ice shelves and glaciers, some as big as Washington state.

Warm ocean waters are carving away the undersides of Antarctica's ice shelves, which will speed their melting

«If we remove these buttressing ice shelves, unstable ice thicknesses would cause the grounded West Antarctic Ice Sheet to retreat rapidly again in the future.

Now, a new study led by Colorado State University provides important details on the extent of sea ice, which can protect ice shelves from the impacts of ocean storms, in the Antarctic Peninsula.

«Instead of emerging at the surface, much of that heat is melting the ice shelves,» Hansen says, producing more fresh water and amplifying the feedback.

Today, as warming waters caused by climate change flow underneath the floating ice shelves in Pine Island Bay, the Antarctic Ice Sheet is once again at risk of losing mass from rapidly retreating glaciers.

increasing air temperatures on the Antarctic Peninsula, which can enhance surface melting of ice shelves,

But the rift itself — how fast that cut through and what held it up — is teaching us a lot about ice shelves.

This has included the complete disintegration of four ice shelves, the floating extensions of glaciers.

Since ice shelves act like plugs, removing them lets inland glaciers flow faster into the ocean, and that will raise sea levels.

After further analysis of the data, the scientists found that although a strong El Niño changes wind patterns in West Antarctica in a way that promotes flow of warm ocean waters towards the ice shelves to increase melting from below, it also increases snowfall particularly along the Amundsen Sea sector.

Healthy ice shelves tend to shed, or «calve,» large, tabular icebergs, sometimes larger than the state of Rhode Island.

When floating ice shelves disintegrate, they reduce the resistance to glacial flow and thus allow the grounded glaciers they were buttressing to significantly dump more ice into the ocean, raising sea levels.

A new study published Jan. 8 in the journal Nature Geoscience reveals that strong El Nino events can cause significant ice loss in some Antarctic ice shelves while the opposite may occur during strong La Nina events.

Dr Gudmundsson said: «Although floating ice shelves have only a modest impact on of sea - level rise, ice from Antarctica's interior can discharge into the ocean when they collapse.

Scientists need to better understand why and how fast the ice shelves are disintegrating so that they can better estimate future sea - level rise.