Topography of the ocean floor Ocean Bathymetry Topography of the ocean floor

Main Regions Continental Margins – drowned edges of the continents Deep-ocean Basins – the ocean floor that lies deeper than 2000 m Mid-ocean Ridges – a continuous underwater mountain range that winds its way through all the oceans

Continental Margins From the land: Continental shelf – almost flat, gradual slope seaward at the edges of the continents; covered with sediments from the land Continental slope – steeper slope seaward; contains submarine canyons Continental rise – shallower slope composed of sediments that have fallen from slope.

Continental Margin

Deep-Ocean Basins Lie beyond the continental margins and contain: Abyssal plains – very flat areas at depths of 3-5 km Seamounts – underwater volcanoes, some > 1000 m high Deep-sea trenches – steep-sided, long, narrow depressions. Deepest regions on earth; found near continental margins

Deep-Ocean Basins

Mid-Ocean Ridges Underwater mountain ranges that are the longest on earth Occupy 1/3 of the ocean floor Not all are “mid-ocean” Contain rift valleys at the summits as well as many fracture zones, where rocks have cracked and slid past one another

Mid-Ocean Ridges

Mid-Ocean Ridge Locations

                                   

Which coast has the wider shelf?