Land of Lakes During the last ice age which occurred during the Pleistocene Epoch (2.55 million &nda
Land of Lakes During the last ice age which occurred during the Pleistocene Epoch (2.55 million – 11.7 thousand years ago) glaciers grew abundant throughout the world. Ice sheets on North America and Eurasia came to be thousands of feet thick and at one point, 1/3 of the earth’s surface was intermittently covered by ice. Large U-shaped valleys are evidence of a greater and icier past many of North America’s present day mountain ranges. Nearly all of the ice has since then melted, leaving most of the bone-chilling story hidden in the ground, the rocks, the oceans, and lakes that now surround us today. This image, for example, shows the many lakes (many of which are pluvial lakes) of just a small portion of the Nunavut Territory, the northernmost territory in Canada. The lakes and rivers are various shades of blue, while the vegetated land is represented in red. The image was taken by NASA’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on the Terra satellite. The technique combines various wavelengths to create false-color images. It is useful in this particular case because it allows us to see Canada’s lakes which otherwise would usually become lost in the natural greens and browns of the foliage. –Pete D Photo Credit: NASA References: 1. http://earthobservatory.nasa.gov/IOTD/view.php?id=78527 2. http://pubs.usgs.gov/gip/ice_age/ice_age.pdf 3. http://www.livescience.com/6937-ice-ages-blamed-tilted-earth.html -- source link
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