Saying an ice skater moves like an avalanche might insult the skater, unless of course you're talking about hockey. Eight home wins in a row gave the Colorado Avalanche momentum they took on the road and turned into a surprise attack on Minnesota Wild winning 4 to 2 on Monday and brought home again yesterday with a 3 to 2 win against the Phoenix Coyotes. Physicists will say they've earned their namesake.
Barbara Turnbull, a researcher at the University of Nottingham in the UK, created a model avalanche to study those properties of frozen water which allow figure skaters to glide like swans and hockey skaters as well as mountain ice avalanches to charge like polar bears. Her research was recently published in the journal Physical Review Letters.
On the ice rink, a phenomenon known as pre-melting creates a liquid-like film on the ice, although it is below freezing. The slippery semi-liquid surface allows professionals to skate faster than 50 miles per hour (80.5 kph).
Something similar happens in an ice avalanche.
"With the ice avalanches, heating through frictional collisions enhances pre-melting and the volume fraction of liquid increases as a result," Turnbull told Discovery News.
Increasing amounts of slippery semi-liquid allow normally sluggish glaciers to accelerate into surging ice avalanches.
Ice avalanches result from the rapid collapse of glaciers or ice packs, as opposed to snow or rock avalanches. Ice avalanches slide as fast as 320 kilometers per hour (200 mph), according to Thinkquest.org.
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To create her ice avalanche model, Turnbull froze droplets of water in liquid nitrogen, then placed them in a rotating drum. Although the air temperature remained below freezing, high speed cameras revealed that the frozen water pellets melted slightly after collisions, increasing their speed of movement. Capillary forces caused the particles to then clump together and flow even faster.
The feedback loop created when increased speed causes more collisions followed by even more increased frictional heating and speed, helps to explain why ice avalanches can be so sudden and unpredictable.
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"Ice avalanches can be particularly devastating," said Turnbull in an interview with Inside Science News, "They often trigger secondary flows."
In 1970, an ice avalanche in Peru did just that. After an earthquake shook a glacier loose, the sliding ice brought 80 million cubic meters (104 million cubic yards) of rock, snow and ice down with it. The towns of Yungay and Ranrahirca were buried, killing at least 20,000.
IMAGES:
Goalie Mathieu Garon #32 of the Tampa Bay Lightning turns back a shot by T.J. Galiardi #39 of the Colorado Avalanche at the Pepsi Center on Dec. 23, 2011 in Denver. The Avalanche defeated the Lightning 2-1 in overtime. (Doug Pensinger/Getty Images)
The north face of King Peak is one of the steepest, most dangerous and difficult mountain walls in the world. A number of hanging glaciers cling to the upper reaches of King Peak, and chunks of these glaciers calve off and roar down the face in dramatic avalanches. (Ed Darack/Corbis)
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