Caption:
Topographical map of the Earth, centered on 45 degrees North, 90 degrees West. Visible are the mid- Atlantic Ridge in the Atlantic Ocean (at right), and Pacific Coast Ranges of western North America (dark brown area), notably the Rocky Mountains. The seas and oceans are color-coded by depth and land colors are based on MODIS true-color data from the Terra satellite in 2004 where darker regions represent highlands. Turquoise regions represent the continental shelf and descend to around 150 meters before dropping off abruptly at the shelf break. The descent of the continental slope to the ocean floor is shown as increasingly dark shades of blue.