This Envisat image highlights three of the five Great Lakes of North America. Lakes Huron (left) and Erie (bottom) are partially ice-covered following snow storms in Michigan and Cleveland, while Lake Ontario (right) is completely visible in blue. The dark blue lines beneath Lake Ontario are some of the Finger Lakes in Upstate New York. A part of the Appalachian Mountains is visible in the bottom left. This image was acquired by Envisat's Medium Resolution Imaging Spectrometer (MERIS) instrument on 22 February 2009, working in Full Resolution mode to provide a spatial resolution of 300 metres.