Ocean BathymetryTopography of the ocean floor

Main RegionsContinental Margins – drowned edges of the continentsDeep-ocean Basins – the ocean floor that lies deeper than 2000 mMid-ocean Ridges – a continuous underwater mountain range that winds its way through all the oceans

Continental MarginsFrom the land:

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

Continental Margin

Deep-Ocean BasinsLie beyond the continental margins and

contain:Abyssal plains – very flat areas at depths of 3-5 kmSeamounts – underwater volcanoes, some > 1000 m highDeep-sea trenches – steep-sided, long, narrow depressions. Deepest regions on earth; found near continental margins

Deep-Ocean Basins

Mid-Ocean RidgesUnderwater mountain ranges that are the longest on earthOccupy 1/3 of the ocean floorNot 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?