A fresh blanket of snow traces out the highlands on Russia’s Putorana Plateau, signaling the onset of autumn. This true-color image of the plateau, situated in Northwestern Siberia about 600 km (373 miles) south and slightly east of the Kara Sea, was acquired on September 25, 2003, by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite. The bright white highlighting provides a striking contrast to the deep brown hues of the ancient volcanic plateau. A number of lakes—including the eastern tip of the Khantayskoye (left edge), the Ozera (left center), and the Keta and Lama (moving northward from the Ozera)—appear dark blue in this scene. The eastern portion of the Khantayskoye, and one of the smaller lakes to the north, has a much lighter blue-green appearance, which is probably due to sediments suspended near the surface from runoff flowing into the lakes.
Some of the lakes in the narrow valleys (lower right) are just beginning to freeze over. One of the lakes running north-south in this scene (lower right) appears to be almost completely glazed over with ice, while the smaller lake situated roughly 40 km to the west has ice just beginning to form along its western shore.
Snow cover lingered in the Great Lakes region on February 16, 2008. Against the backdrop of snowy ground appear the deep blue waters of the Great Lakes and nearby water bodies. In this wintertime shot, the lakes are relatively ice-free, except for Lake Erie.
Huge sheets of ice carved out the U-shaped valleys that hold New York’s Finger Lakes. When they retreated north about 10,000 years ago, glaciers left deposits of gravel that dammed streams and caused the depressions to become lakes.