Posts Tagged "Alps"

Glacier Archaeology Comes of Age

Posted by on Dec 12, 2014 in All Posts, Featured Posts, Science | 1 comment

Glacier Archaeology Comes of Age

Spread the News:ShareHave you heard of Ötzi? One of the world’s best-preserved mummies, he immediately became an archaeological sensation when he came to light in 1991, and new details of his story have been surfacing in scientific journals, magazines, television programs and on the radio ever since—Radiolab dedicated an entire episode to Ötzi just last year. A 45-year-old Neolithic man, fully clothed and carrying a backpack, an axe, a dagger, medicinal plants, and many other personal belongings, he was discovered by a pair of hikers in the Ötzal Alps of Italy lying face down in glacial ice and meltwater. At first the hikers thought he was the victim of a recent mountaineering accident. But when scientists took a look, they discovered the body was over 5,000 years old. Ötzi could be considered the poster child for what has since become its own branch of study: glacier archaeology. Though it has been over two decades since Ötzi was discovered, and many more major finds have surfaced in melting ice and snow in the time since then, glacier archaeology is a field that is only now coming into its own. While one-offs like Ötzi and other mummies have made thrilling finds, the potential for recovery of new artifacts is growing as glacial melt accelerates around the globe. Just this November, the first journal dedicated exclusively to glacier archaeology launched: it’s called, suitably, The Journal of Glacier Archaeology. “There is immediacy to this research,” write the editors in an introduction to the journal’s first annual issue. “Climate models suggest that in the next decades many sites will be lost to melting and decay. Consequently, it is imperative to extend the geographic scope of this research now.” Once the artifacts thaw, they begin to decompose, and shrivel up, which makes them less valuable to researchers, which has lent the hunt for finds a sense of urgency. Vast regions of Asia, Europe, and North and South American have so far been virtually untouched by the discipline. Identifying good new sites in remote glaciated regions of the world is increasingly being done with the aid of advanced technology: not just aerial photography and helicopter surveys, but satellite imagery and geographic systems modeling. The first issue of the journal offers, among other things, an overview of findings about the impeccably preserved 500-year-old “Inca Ice Maiden” and two other mummified Inca children, discovered together in 1999 on Mount Lullaillaco in northwestern Argentina and understood to be human sacrifices; a pollen analysis of caribou dung found on ice patches in the Yukon; a discussion of bronze age arrows found in Norwegian alpine snow patches (see below); and an analysis of GIS (Geographic Information Systems mapping) methods used by glacial archaeologists. A series of annual meetings called “Frozen Pasts,” first launched in Switzerland in 2008, provided the impetus for the new journal, according to Martin Callanan, a glacial archaeologist at Norwegian University of Science and Technology in Trondheim and managing editor of the journal. “It’s a bottom-up thing—people working with the same things, the same complex phenomena, the same findings, all finding each other and saying something is going on here, and it’s global, we need to have regular meetings and a proper publication for ourselves,” he says. “It’s its own special little field…we’ve only started looking.” The Cryospheric Gallery The funny thing about the term glacial archaeology is that most artifacts recovered intact from melting snow and ice actually come from what are called snow and ice “patches,” according to Callanan. That’s because snow and ice patches don’t grow and recede the way glaciers do, making them less likely to crush...

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Roundup: Measuring Ice, Alpine Lakes’s Biota, Risky Glacier Trek, IceBridge

Posted by on Nov 17, 2014 in All Posts, Featured Posts, Images, News, Science | 0 comments

Roundup: Measuring Ice, Alpine Lakes’s Biota, Risky Glacier Trek, IceBridge

Spread the News:ShareHow much ice is left underneath Alaska’s glaciers “Scientists are trekking across Ruth Glacier in Denali National Park in Alaska, dragging a sled with ground-penetrating radar equipment over the ice. Their mission: reconstruct this glacier’s history and find out how much time these icy giants have left. “So what we’re interested in doing is looking at the relationship between temperature and precipitation rate and the response of glaciers in these areas to those changes,” says Karl Kreutz, a paleoclimatologist at the University of Maine.” Read more at PBSNewshour.   Impact of glacier retreat on biota of Alpine lakes “The rapid current retreat of glaciers constitutes one of the most prominent signs of climate change. Glacier retreat enlarges existing lakes and at the same time is creating new ones at the glacier terminus. A remarkable characteristic of glacier-fed lakes is their high content of suspended minerogenic particles, so-called ‘glacial flour’. The overarching objective of this proposal is to understand the consequences of glacier retreat for the structure and function of the biota of alpine lakes and to understand the governing ecological conditions in glacier-fed lakes, particularly of those recently created.” Read more at Lake & Glacier Research Group.   Trek in Glacier National Park “A near-fatal winter solo travel in Glacier National Park from Bowman Lake to Kintla Lake is one of several excursions Richard Layne will discuss at a meeting of the Bitterroot Cross Country Ski Club” Read more at Missoulian.   IceBridge Surveys More of West Antarctica “On Nov. 5, the IceBridge team carried out a survey of the Ferrigno and Alison ice streams and the Abbot Ice Shelf and ice along the Eights Coast. Weather forecasts showed clear conditions in West Antarctica, which typically only last for a few days. Less certain was how cloud cover would look in the Bellingshausen Sea, home of one of the mission’s highest priority flights. That uncertainty is what led mission planners to the decision they made.” Read more at NASA.   Spread the...

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As Glaciers Melt, They Hum Too

Posted by on Nov 4, 2014 in All Posts, Featured Posts, News, Science | 0 comments

As Glaciers Melt, They Hum Too

Spread the News:ShareThe hills are alive with the sound of… humming? Scientists from the U.S., France and Switzerland recently found that as glaciers melt, they make a low humming sound as water passes through them, according to a new study appearing last month in the journal Geology. The phenomenon was first observed in the Swiss Alps when a research team placed seismometers near a glacial lake dammed by the Gorner Glacier on the side of the Monte Rosa Massif in an effort to monitor signs of glacier lake outburst floods (GLOFs). As the water from the lake drained through the glacier, the seismometers picked up tiny “harmonic tremors” in the mountain glacier, as well as similar humming sounds made by icequakes near the glacier’s base. Part of the reason for the humming is that glaciers aren’t just big solid blocks of ice. Water moves through glaciers in an ever-evolving and complex series of tiny cracks, crevasses and channels (hydrofractures) within the glaciers themselves. Small pockets of water open and close within glaciers all the time as water flows from one part to another. Though how exactly this englacier water (that is, water within a glacier) moves isn’t yet fully understood. The seismographs were able to measure the hums as water-filled cracks within the glacier opened and closed, but the humming noises were often at such a low frequency that a human ear could not detect them. Humming glaciers are more than just a curious scientific phenomenon. The paper’s authors state that further research into the hums at the Gorner Glacier might lead to the development of an early warning system against GLOFs. In other words, glaciers may have a built-in alarm systems. GLOFS are difficult to predict because water draining from the lakes can follow a number of different paths over, under or through a glacier that is acting as a boundary or border for the lake, holding the lake water in place. Just watching the surface of the lake isn’t enough to predict when a massive flood will occur. Fortunately, when glaciers go, they don’t go quietly. Spread the...

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Icelandic Zombie Glacier Survives by Shedding Dead Bits

Posted by on Oct 28, 2014 in Adaptation, All Posts, Featured Posts, News, Science | 0 comments

Icelandic Zombie Glacier Survives by Shedding Dead Bits

Spread the News:ShareIt’s alive! British scientists recently discovered that a glacier named Falljökull in Iceland, considered dead, is in fact partially “alive.” Using 3D imaging of the interior and surface of the glacier, they found that its long top section, which extends in a steep ice fall from the ice cap Öraefajökull to a plateau below, has at least temporarily saved itself by severing ties with a lower stagnant, dead piece. It brings to mind that lone hiker pinned under a rock who hacked off his arm a few years ago to escape certain demise in the wild. Perched as it is between dead and undead, Falljökull has earned the nickname zombie glacier in the popular press. But it’s not clear whether this unusual glacier behavior of sloughing off dead ice–behavior that had never before been reported–will keep this patient alive over the long run. Today, the glacier’s active, or living, length is about 700 meters shorter than it was five years ago. “It would be nice to think that the behaviour we have described at Falljökull could represent a type of ‘survival mechanism’ whereby steep mountain (Alpine) glaciers can quickly adapt to warming summer temperatures and decreasing snow fall during the winter months,” wrote Emrys Phillips, British Geological Survey research scientist and lead-author of the paper, in an email. But its survival ultimately depends on whether it remains “attached” to the Öraefajökull ice cap, its source, he said. And predicting how the glacier will behave in the future is tricky. Consider snow and ice, and you may conjure barren, unforgiving landscapes that don’t sustain much life. But most glaciers are in some sense “alive,” an idea first proposed by legendary naturalist John Muir in the late 1800s. This means that the vast sheets, bulging tongues and glittering blue crowns of ice that constitute a glacier are mobile. They flow and advance in ice-rivers and ice-falls in winter and retreat in summer, according to seasonal patterns in snowfall and melt and given the pull of gravity that results when giant hunks of packed and frozen H2O are pitched at an alpine angle. Of course, many glaciers are melting faster than they can accumulate new ice from snowfall, wind-blown snow, avalanches and frozen rain in the winter—mostly attributed to rising temperatures and increasing soot and dust in the atmosphere around the globe. This means the seasonal balance between advancing and retreating is thrown off, which can result in such a severe decline in glacier mass that the glacier is declared “dead.” A dead glacier stops moving and simply melts in place, like a giant ice cube in an empty glass on a hot day in summer. At Falljökull, the team of scientists, who published their research in the AGU Journal of Geogphysical Research in October, found that a new ice front has formed between living and dead pieces of the Falljökull glacier, with the living section actually surging up over the dead section into a bulge at a giant fault line. The scientists note that retreat of the original ice front has accelerated since 2007 and is moving at a faster rate than in any 5-year period since annual measurements began in 1932. Meanwhile, the upper part of Falljökull is still flowing forward at between 164 to 230 feet per year. “Although the margin of Falljökull has ceased moving and is now undergoing stagnation, field and photographic evidences clearly show that the icefall remains active, feeding ice from the accumulation zone on Öraefajökull to the lower reaches of the glacier,” the scientists write in the paper. “To accommodate this continued forward motion, the upper section of the glacier below the icefall is undergoing intense deformation (folding and thrusting) and, as a...

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Glacier stories you may have missed this week – 10/6

Posted by on Oct 6, 2014 in All Posts, Featured Posts, News, Science | 0 comments

Glacier stories you may have missed this week – 10/6

Spread the News:ShareCalifornia droughts and glacier melts lead to massive Mt. Shasta mudslide “Experts believe glacial melting, accelerated by the drought, may have released “pockets of water” that destabilized massive ice blocks and causing the debris flow Saturday afternoon in Shasta-Trinity National Forest, officials said.” Read more about Mt. Shasta mudslide in the Los Angles Times.   The culprit of glacier melting – pollution “When Kaser’s team looked at ice cores previously drilled at two sites high in the western Alps – the Colle Gnifetti glacier saddle 4,455 m up on Monte Rosa near the Swiss–Italian border, and the Fiescherhorn glacier at 3,900 m in the Bernese Alps – they found that in around 1860 layers of glacial ice started to contain large amounts of soot.” Read more about how pollution melts glaciers instead of rising temperatures in Climate Central news.   Cooling of the Earth increases erosion rates “Every year, billions of tons of rock and soil vanish from Earth’s surface, scoured from mountains and plains and swept away by wind, rain, and other elements. The chief driver of this dramatic resurfacing is climate, according to a new study. And when the global temperature falls, erosion kicks into overdrive.” Read more about cold climate shrinks mountains in Advancing Science, Serving Society (AAAS) news. Spread the...

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