Sentences with phrase «ice sheets»

What they found, Hansen says, is that melting ice sheets in Greenland and Antarctica could inject enough fresh water into the seas to slow the formation of two key water masses: the North Atlantic Deepwater and the Antarctic Bottom Water formations.

These eight scarps, with slopes as steep as 55 degrees, reveal new information about the internal layered structure of previously detected underground ice sheets in Mars» middle latitudes.

For one thing, he says, it contains a scenario in which the fresh meltwater from ice sheets increases exponentially over time, «which may not be realistic.»

Thus, less moisture is trapped in ice sheets, then more is found in liquid form.

These big ice sheets have frozen and melted many times in the past (producing ice ages with low sea levels and warm periods with high sea levels).

Researchers previously used MRO's Shallow Radar (SHARAD) to map extensive underground water - ice sheets in middle latitudes of Mars and estimate that the top of the ice is less than about 10 yards beneath the ground surface.

Brooke Medley, who was on the flight, studies ice sheets at NASA's Goddard Space Flight Center in Maryland.

They circumnavigated harsh weather and unforgiving terrain until they found the first proof for vanishing ice sheets.

The team stresses that even a little warming could cause irreversible melting of ice sheets and turn dense Amazon forests into dry savannah grassland.

At the time, scientists had hints from satellites, but they weren't sure if the world's major ice sheets were melting.

The Arctic took another 3,000 - 4,000 years to warm this much, primarily because of the fact that the Northern Hemisphere had huge ice sheets to buffer warming, and the fact that changes in ocean currents and Earth's orbital configuration accelerated warming in the south.

It's known that when ice sheets start to melt, cooling the air in that region, the winds over the Southern Ocean strengthen, Toggweiler says.

Rising sea levels are certain in a warming world, but there is still substantial uncertainty about the extent of the increase in this century, mainly because the dynamics that could erode the ice sheets of Greenland and Antarctica remain poorly understood.

This allowed them to calculate the redistribution of mass on Earth's surface due to the melting of the Greenland and Antarctic ice sheets and mountain glaciers, and model the shift in Earth's axis.

Materials scientists hope their computer model results will spark further research into the effects of carbon dioxide on fracturing in glaciers and ice sheets

CReSIS is the Center for Remote Sensing of Ice Sheets, a National Science Foundation science and technology center headquartered at the University of Kansas in Lawrence, Kansas.

Mapping this buried range will help scientists understand how glaciers formed in Antarctica as well as how today's ice sheets interact with the ground below.

ITS vast ice sheets and monsoon run - off make the Tibetan plateau one of the largest sources of fresh water on an increasingly thirsty planet.

This anterior - posterior heat flux is important in preventing these ice mole rats from sinking through the ice sheets and is unknown in any other mammal.

Should Antarctica's ice sheets dissolve, sea levels would rise dramatically — enough to flood the world's great coastal megalopolises from New York to Shanghai and push millions of people inland.

This could have significant implications for Antarctica's ice shelves and ice sheets, with previous research showing that even small increases in ocean temperatures can substantially increase melt rates around the Peninsula.

«That may not sound like a lot, but consider the volume of ice now locked up in the planet's three greatest ice sheets,» she writes in a recent issue of Scientific American.

Such piracy was rampant as the colossal ice sheets of the Last Glacial Maximum began shrinking around 18,000 years ago.

Perhaps extra carbon dioxide from a period of heightened seafloor eruptions eventually percolates through the ocean and into the atmosphere, allowing warming that would deliver a coup de grâce to the massive ice sheets.

This isn't the first time ice sheets have calved from the Greenland mainland, but it's one of the largest breaks.

Antarctica's vulnerability to climate change has also become increasingly clear, said Robin Bell of Columbia University's Lamont - Doherty Earth Observatory, who studies how ice sheets change.

Abundant liquid water newly discovered underneath the world's great ice sheets could intensify the destabilizing effects of global warming on the sheets.

The warming ocean and atmosphere that are already melting glaciers and ice sheets produce a catastrophic rise in the ocean.

But microscopic phytoplankton, which rely on the sun for their nutrients and form the base of Arctic food webs, have managed to thrive under ice sheets that are thinning as the poles become warmer.

And since few rocks naturally form on the ice sheets, the majority of Antarctic rocks collected are extraterrestrial.

«It's a benchmark to compare what the ice sheets were like, with now.»

Countless additional forces — melting ice sheets, shifts in precipitation, changes in atmospheric and oceanic circulation, to name a few — will influence the process as well.

But understanding what is happening down there, so far from human view, will be crucial for predicting the future fate of Antarctica's ice sheets amid rising temperatures.

One way to assess the health of ice sheets is to look at their balance: when an ice sheet is in balance, the ice gained through snowfall equals the ice lost through melting and iceberg calving.

From 500 feet up everything appeared in miniature except the giant ice shelves — seemingly endless expanses of ice, as thick as the length of several football fields, that float in the Southern Ocean, fringing the ice sheets that virtually cover the Antarctic landmass.

I spend a lot of time studying the ice sheets at the bottom of the planet — how they form and how they collapse.

The hope is that the cables could reveal secrets about what's happening underneath the ice sheets, especially about melting at the so - called grounding line, the place where the bottom of an ice sheet meets the slightly warmer ocean.

Large areas of the Earth's surface are experiencing rising maximum temperatures, which affect virtually every ecosystem on the planet, including ice sheets and tropical forests that play major roles in regulating the biosphere, scientists have reported.

Scientists have suggested that ice sheets covering the ocean, or a hydrogen - sulfide haze, might have protected nascent life, but attempts to model these conditions have given ambiguous results.

Evidence of past glacial advance and retreat is also more easily observed in the Dry Valleys, providing a window into the past behavior of the vast Antarctic ice sheets and their influence on global sea levels.

The only current ice sheets are Antarctic and Greenland; during the last ice age at Last Glacial Maximum (LGM) the Laurentide ice sheet covered much of Canada and North America, the Weichselian ice sheet covered northern Europe and the Patagonian Ice Sheet covered southern South America.

If the great ice sheets of Greenland and Antarctica lose enough ice to raise sea level a metre or more, though, it would take thousands of years for snowfall to build up the ice sheets again.

We may have already changed the ice sheets to a point that some parts of them may go, but we have the ability to stop changing it more and to adapt to what we have already done.

The 2007 IPCC report assumed that the two ice sheets would contribute just 0.3 millimetres a year to sea - level rise for the next century.

As the volcano vented lava beneath the thick ice sheets, it released huge quantities of liquid water within the glacier.

We know that the ice sheets are decreasing.

The ice sheets rearrange themselves through what Beauchamp calls «ice tectonics,» like plate tectonics on Earth.

Yet these model - based estimates do not include the possible acceleration of recently observed increases in ice loss from the Greenland and Antarctic ice sheets.

Things are really bad like losing ice sheets, starting to raise sea levels, where coastlines have to be redrawn and people have to move.

Mote was one of 12 lead authors on a chapter of the fifth Intergovernmental Panel on Climate Change report looking at the cryosphere, which is comprised of snow, river and lake ice, sea ice, glaciers, ice sheets and frozen ground.