The Sea Floor or Ocean Basins Oceans The Sea Floor or Ocean Basins

Continental shelf - The underwater gradual slope at the boundaries of the continents. Can be as narrow as 6 miles or as wide as 200 miles.

Continental Slope – the steep drop off in gradient from the edge of the shelf down to the ocean floor Continental Slope

Abyssal Plains – The flat valley of the seafloor covered by mostly sediment from land erosion

Seamounts – Underwater hills and inactive volcanos found on the abyssal plains

Mid-ocean ridge – underwater mountain ranges formed where crustal plated pull apart and new ocean floor is created from the escaping magma

Sea floor spreading

Largest Mountain Ridge in the world Mid-Atlantic ridge Largest Mountain Ridge in the world

Subduction Zone – an area where two crustal plates collide and one slides under the other, Also forms ocean trenches Subduction Zone

I. Resources from the Continental Shelf Oil and Natural Gas 1. 20% of the world’s oil comes from the seafloor 2. Extracted by drilling wells from platforms

I. Resources from the Continental Shelf (continued) B. Phosphorite and Limestone Used for fertilizer and concrete

I. Resources from the Continental Shelf (continued) C. Food Seafood delicacies: Lobster, Rays, Eel, Urchin As additives –Seaweed and Kelp

II. Resources from the Deep sea There are many rare resources in the deep sea. Cost and lack of technology to mine from extremely deep depths currently prevent mining in this location.

CO2 + H2O + Sunlight  O2 + Sugar Ocean Life Photosynthetic Life - Life that uses sunlight and carbon dioxide to make food and oxygen CO2 + H2O + Sunlight  O2 + Sugar Oxygen Water CO2

Ocean Life Chemosynthetic Life – bacteria that uses chemicals to create food a. Examples use sulphur and nitrogen compounds as an energy source b. They live along the bottom of the ocean near hydrothermal vents

Ocean Life Plankton – microscopic Life that photosynthesizes a. The primary food source for marine life b. Float with the ocean current c. Produce 50% of the world’s oxygen

Ocean Life Nekton – animals that actively swim in the ocean currents a. they control their buoyancy – float/sink

Ocean Life Benthos – bottom dweller. Plant or animals that live at the ocean floor a. crabs, lobsters, urchins, anemones, sponges

Shoreline terms Beaches – sandy coasts, constantly changing due to wave action Rocky shore – rocks along the coast, more stable, still have wave actions Tidal pools – trapped water puddles, used by marine live to raise their young away from the dangers of the open ocean