- Continental Shelf
- Continental Slope
- Deep Sea Plains
- Oceanic Deeps and Trenches
- Submarine Canyons
1. Continental Shelves
- If there is a high mountain, closer to and parallel to the coast near the ocean than continental shelves will be narrow. Example- Pacific Continental Shelf(only 16 Kms) along Andes Mountain in South America.
- When wide plains are along the coast than the shelves will be wider. Example - North America (East Coast) - 96-120Km
- Formed due to subsidence of continental Coasts due to rising thermal convective shells beneath the Earth.
- Due to prolong Detritus deposition by rivers near the coast (generally formed in Calm Oceans/Seas).
- Faulting of Continental blocks due to Tectonic activities.
- Fall in sea level either due to glaciation or subsidence of oceanic floors.
- Bending/tilting of continental plate towards ocean due to Tectonic activities.
- Marine Erosion by Ocean Currents and fluvial deposition brought by rivers.
- Due to formation of wave cut platforms.
2. Continental Slopes
- Formed due to faulting of Continental Shelves due to rising Convective Limbs.
- Erosion by Marine Waves.
- Bending and Warping of Continental shelves followed by sedimentation.
3. Deep Sea Plains
4. Oceanic Deep/Trenches
- Deeps - very deep but narrow belt.
- Trenches - Long and extensive and parallel to the coast or Island.
5. Submarine Canyons
- Glacialy eroded canyons (very few in number)
- Non-glacial canyons (widely spread)
- Disastrophic Theories (Tectonic activities).
- Erosion by river and later Sea level rose(Sub-arial Theory)
- Submarine Density Current Theory(Ocean Current formed due to difference in temperature and salinity).
- Turbidity current Theory.(Current with suspended sediments eroded the continental shelves).