Global topography. Topographical map of the Earth,centred on 45 degrees North,180 degrees East. The seas and oceans are colour-coded by depth. Turquoise regions descend to around 150 metres,and show the continental shelf. This drops off abruptly at the shelf break,where the continental slope descends to the deep ocean floor (seen as increasingly dark shades of blue). The deepest point on Earth is in the Mariana Trench,at the bottom of the dark arc at lower left. Numerous volcanic islands and seamounts are seen in the Pacific Ocean,as is the shallow strait between Siberia,Russia,and Alaska,USA. Land colours are based on MODIS true-colour data from the Terra satellite in 2004. Highlands are seen as darker regions |