Along Greenland's western coast, a small field of glaciers empties into Baffin Bay, 80% of which is covered by ice in winter. Calving icebergs may be seen in the lower right of this high-resolution satellite photo. Baffin Bay is only 1,000 m (3,300 ft) deep along the coast. Between May and July a polynya, an area of navigable open water surrounded by sea ice, forms at the northern part of the bay. This polynya, the largest in the Canadian Arctic, is stable in location and has existed for nearly 9,000 years. Image courtesy of USGS.