 |
|
Permanent ice fields are resisting global warming
May 17, 2007The small ice caps of Mont Blanc and the Dôme du Goûter are not melting, or at least, not yet. This is what CNRS researchers1 have announced in the Journal of Geophysical Research. At very high altitudes (above 4200 meters), the accumulation of snow and ice has varied very little since the beginning of the 20th century. But if summer temperatures increase by a few degrees during the 21st century, the melt could become more marked, and could affect the "permanent" ice fields.
Alpine glaciers, which are mainly at an altitude between 2000 and 4000 meters, shrank considerably during the 20th century and particularly during the past twenty years, losing an average of 1 to 1.5 kilometers in length. However, the situation is different above 4200 meters.
At the altitude of the Dôme du Goûter (4300 m) or the summit of Mont Blanc (4810 m), all precipitation is solid, falling as snow. The ice fields melt very little, and only in extreme conditions such as the 2003 heatwave. Variations in the mass of glaciers only depend on the accumulation of snow and the downward flow of the glacier, as the ice is deformed under its own weight.
In order to study these mass balance fluctuations, the research team measured the rate of accumulation of snow on the Dôme du Goûter since 1993, and the thickness and flow rate of the glacier. They also used meteorological data from Chamonix, from 1923 to the present day, to calculate the rate of accumulation of ice during the 20th century. Or, more precisely, they used data on the precipitation in Chamonix, altitude 1036 meters, to extrapolate for quantities of snow fallen on the glacier, and so to calculate the mass balance.
Based on this data, the glaciologists have shown that at these very high altitudes, the ice mass balance has remained almost constant over the last 100 years. They have also used old topographical maps to show that the thickness of these small ice caps on Mont Blanc and the nearby Dôme du Goûter has only changed by a few meters from 1905 to 2005. By comparison, at a lower altitude (1800 meters), the thickness of the Mer de Glace has decreased by 120 meters over the same period.
So the Mont Blanc and Dôme du Goûter ice fields have not yet been affected by climate change. However, during exceptional climatic events like the 2003 heatwave, positive temperatures caused some of the surface ice to melt. If episodes like this were to occur more often, this partial melting would no longer be negligible, and would have a significant effect on the ice mass. So there is no guarantee that "permanent" ice fields will stay that way in the future.
CNRS
In order to study these mass balance fluctuations, the research team measured the rate of accumulation of snow on the Dôme du Goûter since 1993, and the thickness and flow rate of the glacier. They also used meteorological data from Chamonix, from 1923 to the present day, to calculate the rate of accumulation of ice during the 20th century. Or, more precisely, they used data on the precipitation in Chamonix, altitude 1036 meters, to extrapolate for quantities of snow fallen on the glacier, and so to calculate the mass balance.
Based on this data, the glaciologists have shown that at these very high altitudes, the ice mass balance has remained almost constant over the last 100 years. They have also used old topographical maps to show that the thickness of these small ice caps on Mont Blanc and the nearby Dôme du Goûter has only changed by a few meters from 1905 to 2005. By comparison, at a lower altitude (1800 meters), the thickness of the Mer de Glace has decreased by 120 meters over the same period.
So the Mont Blanc and Dôme du Goûter ice fields have not yet been affected by climate change. However, during exceptional climatic events like the 2003 heatwave, positive temperatures caused some of the surface ice to melt. If episodes like this were to occur more often, this partial melting would no longer be negligible, and would have a significant effect on the ice mass. So there is no guarantee that "permanent" ice fields will stay that way in the future.
CNRS
Ice Fields Current Events and Ice Fields News RSSAncient drought and rapid cooling drastically altered climate
Two abrupt and drastic climate events, 700 years apart and more than 45 centuries ago, are teasing scientists who are now trying to use ancient records to predict future world climate.
New Tibetan ice cores missing A-bomb blast
Ice cores drilled last year from the summit of a Himalayan ice field lack the distinctive radioactive signals that mark virtually every other ice core retrieved worldwide. That missing radioactivity, originating as fallout from atmospheric nuclear tests during the 1950s and 1960s, routinely provides researchers with a benchmark against which they can gauge how much new ice has accumulated on a glacier or ice field.
Glaciers and ice caps to dominate sea level rise this century, says CU-Boulder study
Ice loss from glaciers and ice caps is expected to cause more global sea rise during this century than the massive Greenland and Antarctic ice sheets, according to a new University of Colorado at Boulder study.
Fabled equatorial icecaps to disappear
Fabled equatorial icecaps will disappear within two decades because of global warming, a study led by UCL (University College London) has found.
Fabled equatorial African icecaps to disappear
Fabled equatorial icecaps will disappear within two decades, because of global warming, a study British and Ugandan scientists has found.
Snows of Kilimanjaro disappearing, glacial ice loss increasing
Five years after warning that the famed ice fields on Tanzania 's Mount Kilimanjaro may melt, Ohio State University researchers have sadly found that their prediction is coming true.
ERS altimeter survey shows growth of Greenland Ice Sheet interior
Researchers have utilised more than a decade's worth of data from radar altimeters on ESA's ERS satellites to produce the most detailed picture yet of thickness changes in the Greenland Ice Sheet.
Our planet is star of the Earth and Space Expo
Visiting the Earth and Space Expo in Brussels is like nowhere else on Earth - you even take what seems like a walk through the sky to get inside! During the weekend upwards of 9000 visitors made the journey to experience a wide range of displays, interactive exhibits and breathtaking space-based views of our planet. Those entering the Expo, at Autoworld in the Parc du Cinquantenaire, find that carefully placed mirrors on the floor, walls and ceiling give a sense of spacewalking beyond the atmosphere. Some visitors have to slow down to make sense of it - but keep on going to find themselves in a 3000 square metre exhibition area - presented jointly by ESA and the European Commission, with
Summit agrees to improve coordination of global Earth observation
High-level delegates from 30 countries and 22 international organisations agreed at the Earth Observation Summit held last Thursday in Washington to improve cooperation on Earth observation and to remove barriers to the exchange of information between countries and organisations. ESA already carries out its Earth observation programmes in cooperation with other agencies or countries through mechanisms such as CEOS, the Committee of Earth Observation Satellites and IGOS-P, the Integrated Global Observing Strategy Partnership. Another good example of the way cooperation between space agencies can lead to increased utilisation of EO data is the International Charter on Space and Major Disaste
CryoSat takes significant step towards final completion
CryoSat, the first Earth Explorer mission within ESA's Living Planet Programme, is now entering the final phase of assembly prior to its scheduled launch next year. CryoSat is designed to measure changes in the Earth's terrestrial and marine ice fields and aims to provide conclusive evidence as to whether there is a trend towards diminishing polar ice cover as a result of climate change. The first part of the Critical Design Review (CDR), which was successfully completed on 13 June, confirmed that the flight configuration design is compliant with the key design requirements and can now be integrated and tested. This step marks the beginning of the final phase of assembly of the spacecraft.
More Ice Fields Current Events and Ice Fields News Articles
 |
Icefields by Thomas Wharton (Author) Winner of: The Banff Grand National Prize for Literature The Writers Guild of Alberta Best First Book Award The Commonwealth Best First Novel Prize (Caribbean and Canada Region) At a quarter past three in the afternoon, on August 17, 1898, Doctor Edward Byrne slipped on the ice of Acturus glacier in the Canadian Rockies and slid into a crevasse . . . Nearly sixty feet below the surface, Byrne is wedged upside down between the narrowing walls of a chasm, fighting his desire to sleep. The ice in front of him is lit with a pale blue-green radiance. There, embedded in he pure, antediluvian glacier, Byrne sees something that will inextricably link him to the vast bed of ice, and the people who inhabit this strange corner of the world. In this moment, his life becomes a quest... |
 |
C1920 Ice Field America Industry Post Office Store Shop by old-print c1920 ICE FIELD AMERICA INDUSTRY POST OFFICE STORE SHOP A Page and reverse from People of All Nations, their life story today and the story of their past captured in numerous photographs edited by J A Hammerton .Countries include south Africa, Spain, Sweden, Switzerland, Syria, Tasmania, Tibet, Tunis, turkey, Turkistan, the Ukraine, the united states, Uruguay, Venezuela, and Wales .Dates c 1920 size of each page is approx 9.5 x 6 inches (240 x 150) all are genuine prints and not copies. |
 |
Mens Patagonia Ice Field Jacket Large by Patagonia The Ice Field Jacket by Patagonia is a burly waterproof/breathable, superwarm high-loft insulated hard shell jacket for cold and wet endeavors. Features: Waterproof/breathable H2No barrier and Deluge finish; 2.5-layer stretch polyester body wtih reinforced shoulders, arms and waist 100-gram PrimaLoft Eco synthetic insulation (50% recycled) throughout provides superior warmth and compressibility 2-way-adjustable hood has internal stand-up collar Highly water-resistant, coated zips on all exterior zippers Pit zips Pockets: two handwarmers, two chest, one internal security and one large mesh drop-in Low profile, laminated, self-fabric cuff tabs Drawcord hem Regular fit Weight: (33.4 oz) 947 oz |
 |
Ice Field (Original Mix) Conversation 3 (Primary Contributor) |
 |
Cosmos Global Documentaries FIRE & ICE Iceland Directed By: TravelVideoStore.com Also With: TravelVideoStore.com (Producer) |
 |
Patagonia Ice Field Jacket - Women's by Patagonia The weekend weather looks wet and cold, and ice climbing and touring are on the agenda. The Patagonia Womens Ice Field Jacket brings insulation and waterproof breathable fabric to your outdoor ensemble. The light side and arm insulation in this hardshell wont restrict your movement at the belay station, while Climashield Green insulation in the body adds core warmth. PU-coated Underarm zips regulate your temperature on backcountry tours, and the adjustable hood blocks wind once you reach the ridge. Product FeaturesMaterial: [Shell] 2.5-layer polyester (100% recycled), H2No barrier, DWR finish; [Insulation]Climashield Green 100% recycled polyester in body, 60g EcoTherm 90% recycled polyester panelsWaterproof Rating: Not specifiedBreathable Rating: Not specifiedCore Venting:... |
 |
The Cutting Edge - Gold Medal Edition Starring: D.B. Sweeney, Moira Kelly, Roy Dotrice, Terry O'Quinn, Dwier Brown Directed By: Paul Michael Glaser Also With: Elliot Davis (Cinematographer), Cynthia Sherman (Producer), Dean O'Brien (Producer), Karen Murphy (Producer), Robert W. Cort (Producer), Ted Field (Producer), Tony Gilroy (Writer) Moira Kelly (Dangerous Beauty, "The West Wing") and D. B. Sweeney (Roommates, Memphis Belle) star as polar opposites who unite on the ice for a shot at Olympic gold in this inspirational romantic comedy from acclaimed director Paul M. Glaser (The Running Man). Brimming with wit, charm and plenty of breathtaking sports action, The Cutting Edge is a real winner! She's a rich and refined pairs figure skater whose prima donna attitude has her skating solo. He's a brash, blue-collar hockey champion with a new injury and no future. With nothing in common but their dream of reaching the Olympics, Kate and Doug are each other's last resort. Reluctantly, they join forces, but its not long before the barbs – and sparks – start flying as the unlikely pair skate towards the opportunity of a... |
|
Battle of the Atlantic Suite Dave Roylance (Composer), Bill Connor (Composer), Fanfare Trumpeters of the Band of H.M.Royal Marines (Composer), Hallé (Composer), Hallé Choir (Composer), Lesley Garrett (Composer) | |
 |
Baffin Women's Ice Field Insulated Boot,Black,6 M by Baffin |
 |
9 Inch English Style Ice Cap - Bag / Hot Bottle / Hangover Helper by Graham Field Get natural relief from headaches, migraines, muscle aches & swelling. The old fashioned English style ice bag has long been a method of our grandmothers for relief of headaches, migraines, swollen joins and limbs. Ice bags can reduce muscle spasms and inflammation. Soft bag shapes itself around injured area for good contact. Convenient for use when traveling or camping, or anywhere you have no freezer to chill a gel pack. Just grab ice from a cooler or order it from a food establishment - and its ready to provide hours of cold relief for pain and swelling. This has also been known as a "Hangover" cap for use on that type of headache. On a hot day, this is really refreshing to use. By applying to the back of your neck you can cool yourself quite easily. Ladies of a certain age appreciate... |
| © 2009 BrightSurf.com |