rivers of ice. glacier facts found on every continent- even africa! cover 10% of the earth’s land...
TRANSCRIPT
Rivers of Ice
Glacier FactsFound on every continent- even Africa!Cover 10% of the earth’s land areaContain 75% of the freshwater on earthTwo types:
Alpine (valley glaciers) are found in the mountains
Continental glaciers (ice sheets) are found at the north and south poles
How does a glacier form?Form when more snow falls than melts in one
yearSnow compacts into iceIce begins to flow downhill under its own
weight
How do glaciers work?In winter, ice accumulates at the top of the
glacier, pushing the glacier downhillIn summer, ice melts at the bottom of the
glacier If the amount that melts in the summer is
more than the amount that accumulates in the winter, the glacier retreats
Retreating Glaciers and Global Warming
Holgate Glacier, Alaska, July 1909
Holgate Glacier, August 2004
Retreating Glaciers and Global Warming
Qori Kalis Glacier, Peru, July 1978
Qori Kalis Glacier, July 2004
How are glaciers affected by global warming?All glaciers are getting smaller every year!!Sea level is rising…coastal cities could flood!
Why do geologists care about glaciers?Glaciers have shaped the landscape that we
see now!
Glacial Landscapes
Yosemite Valley, Yosemite National Park, CA
Glacier National Park, Montana
The Matterhorn, Switzerland- Italy Border
Glacial ErosionAs a glacier moves down the side of the
mountain, it scrapes off pieces of the surrounding rock
Over time, a large amount of material can be removed by the glacier
Glacial Features: U-Shaped ValleysWhen a river erodes a valley, the valleybecomes V-shaped Glaciers are wider than rivers, so theychange the shape of the valleyValley becomes U-shaped
Glacial Features: Sharp Ridges (Aretes)Two glaciers on two sides of a mountainWhen glaciers melt, a sharp ridge remains
Glacial Features: Pyramid Peak (Horn)A peak where several sharp ridges meetAt least 3 very steep (nearly vertical) sides Form where several glaciers meet
CitationsLonnie G. Thompson, Byrd Polar Research
Center, the Ohio State University