Sentences with phrase «sheet ice show»
Measurements taken of Antarctic sheet ice show that the concentration of naturally occurring carbon dioxide in the atmosphere was already 278 ppm in the 1750s before industrialization started in earnest.
https://www.sciencedaily.com/ Not exact matches
«These people all commissioned demographic studies that showed they need a year - round sheet of ice.»
But gravity - measuring satellites have shown that the continent's ice sheets have been losing mass since at least 2002.
But new analyses like this, which show previously undiscovered deep canyons, suggest that a good chunk of East Antarctica's bed lies below sea level, rendering the ice sheet less stable than previously thought.
Parts of the massive ice sheet once considered stable have been shown to be melting in new research
However, fresh samples like those we collected on the Greenland Ice Sheet can show a clear wildfire signature.»
While the exact sources of black carbon are often difficult to pinpoint in remote areas, the researchers used molecular analysis of the black carbon along with analysis of wind patterns to show that Greenland's ice sheet had recently seen clear effects of wildfires burning thousands of miles away in the Canadian Arctic.
Even then, many experts disputed this, and satellite measurements have since shown the two sheets are already losing enough ice to raise sea level by 1.3 millimetres a year and climbing.
As an example, Howat pointed to the portion of the mosaic showing Jakobshavn Glacier, the fastest - flowing glacier in the Greenland Ice Sheet.
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.
In effect, this UAV survey across the ablation zone of the ice sheet perfectly bridges the gap between people on the ground studying what's under their feet in just one part of the ice sheet, and the satellite data that shows what's going on across the entire ice sheet.
Later records show those conditions shifted in 2013 - 2014 to favor less melting, but the damage was already done — the ice sheet had become more sensitive.
Thousands of marks on the Antarctic seafloor, caused by icebergs which broke free from glaciers more than ten thousand years ago, show how part of the Antarctic Ice Sheet retreated rapidly at the end of the last ice age as it balanced precariously on sloping ground and became unstabIce Sheet retreated rapidly at the end of the last ice age as it balanced precariously on sloping ground and became unstabice age as it balanced precariously on sloping ground and became unstable.
Their results show that East Greenland has been actively scoured by glacial ice for much of the last 7.5 million years — and indicate that the ice sheet on this eastern flank of the island has not completely melted for long, if at all, in the past several million years.
Their field - based data also suggest that during major climate cool - downs in the past several million years, the ice sheet expanded into previously ice - free areas, «showing that the ice sheet in East Greenland responds to and tracks global climate change,» Bierman says.
Satellite studies of Earth's gravitational field show that North America is still rebounding from the weight of the massive Laurentide Ice Sheet, which retreated thousands of years ago
Previous work by coauthor Beth Shapiro, professor of ecology and evolutionary biology at UC Santa Cruz, had shown that the bison populations north and south of the ice sheets were genetically distinct by the time the corridor opened.
This photo from December 2010 shows a one - meter long section of the West Antarctic Ice Sheet Divide core, with a dark layer of volcanic ash visible.
Another thing that ice core showed, as others have before, is that the great swing in temperature between glacial and interglacial periods was invariably accompanied by great swings in the amount of greenhouse gases in the atmosphere: When the greenhouse goes up, the ice sheets go down.
«This shows the need to continue to look at different components of the climate system, including the ice sheets and oceans, in an integrated sense,» concluded Paul Myers, study co-author and Professor of Oceanography at the University of Alberta.
In the Coast Guard's spring tests, small - scale models navigated an ice sheet as long as one - and - a-half Olympic - sized swimming pools at the National Research Council's ice - tank test facility in Newfoundland to measure various designs» resistance, power and maneuverability (shown below).
A March study shows that one large swath of the ice sheet sits on beds as deep as 8,000 feet below sea level and is connected to warming ocean currents.
Measurements of local gravitational anomalies by the GRACE satellites show that the Greenland ice sheet, particularly in its southern reaches, is rapidly losing mass.
Other recent findings of Bell's — that refreezing meltwater can warp the bottom of the ice sheet — combine with the new study to show «there's a richer range of processes that can happen at the bottom of the ice sheet than we thought,» Bell said.
GRACE showed that the melting polar ice sheets are contributing more to sea level rise than the demise of mountain glaciers.
Sasha Carter, a postdoctoral researcher at the Scripps Institution of Oceanography who studies the Antarctic ice sheet, said the new research «shows that subglacial water transport and the refreezing of that meltwater is reshaping the interior of East Antarctica at a scale previously not believed to be possible.»
Radar images show that water under the base of the ice sheet refreezes into ice, creating a new bottom layer that accounts for up to half the total thickness of the ice sheet in some locations.
«Our model experiments show that from 15000 to 13000 years ago, the Eurasian ice sheet lost 750 cubic kilometres of ice a year.
Earlier studies of lakeshore deposits had shown that the lake was at its highest every 2000 years, matching advances of ice sheets.
New research shows that small fluctuations in the sizes of ice sheets during the last ice age were enough to trigger abrupt climate change.
Based on the southern core we thought this was a localized low heat - flux region — but our model shows that a much larger part of the southern ice sheet has low heat flux.
«Studies have shown that both the Greenland and Antarctic ice sheets contributed significantly to this sea level rise above modern levels,» said Anders Carlson, an Oregon State University glacial geologist and paleoclimatologist, and co-author on the study.
Since then, measurements from other satellites have shown that the ice sheets on both Antarctica and Greenland are shrinking.
A snow pit shows off the season - by - season stratigraphy at the West Antarctic Ice Sheet Divide.
Some say humans could have crossed through an opening between the ice sheets, but these new findings show that passage was likely closed until 13,400 years ago.
A new study by scientists at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, and the University of California, Irvine, shows that while ice sheets and glaciers continue to melt, changes in weather and climate over the past decade have caused Earth's continents to soak up and store an extra 3.2 trillion tons of water in soils, lakes and underground aquifers, temporarily slowing the rate of sea level rise by about 20 percent.
«The main result supports and extends earlier work, showing that human forcing contributes to changing winds that contribute to subsurface ocean warming, affecting some grounding zones of the ice sheet,» Alley said.
But the data Rapley presented show that glaciers within the much larger west Antarctic Ice sheet are also starting to disappear.
But the large volumes of data on Arctic sea and land ice that IceBridge has collected during its nine years of operations there have also enabled scientific discoveries ranging from the first map showing what parts of the bottom of the massive Greenland Ice Sheet are thawed to improvements in snowfall accumulation models for all of Greenlaice that IceBridge has collected during its nine years of operations there have also enabled scientific discoveries ranging from the first map showing what parts of the bottom of the massive Greenland Ice Sheet are thawed to improvements in snowfall accumulation models for all of GreenlaIce Sheet are thawed to improvements in snowfall accumulation models for all of Greenland.
The detailed mapping and sampling of the partially eroded Kima» Kho tuya in northern British Columbia, Canada shows that the ancient regional ice sheet through which the volcano erupted was twice as thick as previously estimated.
«Our work shows that the data collected is very well - suited for ice sheet science, and we can combine it with other satellite and airborne data sets to establish a more detailed record of these glaciers.»
The research shows that volcanic eruptions beneath a glacial ice sheet would have created substantial amounts of liquid water on Mars's surface around 210 million years ago.
«In this study, we are showing that ice sheets, mountain glaciers and ice caps are neck - and - neck.»
Recent projections show that for even the lowest emissions scenarios, thermal expansion of ocean waters21 and the melting of small mountain glaciers22 will result in 11 inches of sea level rise by 2100, even without any contribution from the ice sheets in Greenland and Antarctica.
In the lab, ancient bacteria from ice samples 420,000 years old, retrieved from more than 2 miles (3 km) inside the ice sheet, have quickly shown signs of life.
The fact that ice sheets will respond to warming is not in doubt (note the 4 - 6 m sea level rise during the last interglacial), but the speed at which that might happen is highly uncertain, though the other story this week shows it is ongoing.
Ice cores drawn from Antarctica and Greenland have shown that carbon dioxide (CO2) levels in the atmosphere began to rise at roughly the same time as the vast ice sheets began to meIce cores drawn from Antarctica and Greenland have shown that carbon dioxide (CO2) levels in the atmosphere began to rise at roughly the same time as the vast ice sheets began to meice sheets began to melt.
Despite being trumpeted in certain circles as meaning that there's really nothing to worry about regarding the Greenland ice sheet, the authors made a point of noting (although not in this press release) that an additional source of mass loss needs to be identified in order to reconcile their results with the GRACE data (which do not show a reduction in mass loss for the same period).
The relevant papers are [Velicogna and Wahr 2006 Measurements of time - variable gravity show mass loss in Antarctica Science 311, 1754 - 1756 and Rignot and Thomas «Mass balance of polar ice sheets» Science 297, 1502 - 1506]
Recent research shows that there is high microbial activity on glacial surfaces (Anesio et al., 2009), some associated with pigmented algae, which absorb significantly more light than local inorganic dust particles on the Greenland Ice Sheet (GrIS)(Lutz et al., 2014).