Exploration of the Ocean Oceanography: Oceanographers: study the ocean & its floor up to 6.4 km into the ocean floor Ocean floor: is made up of continental & oceanic crust Submersibles: underwater research vessels Help oceanographers study the ocean depths Bathysphere: early type of submersible used for deep-ocean diving Remained connected to the research ship for communication & life support

Submersibles Bathyscaph: self-propelled, free-moving submarine used for deep-ocean diving Can hold one pilot & 2 scientists Has made new discoveries where life was thought to be non-existant Robot submersibles: enable oceanographers to study the ocean at great depths & long periods of time

SONAR: SOund Navigation And Ranging Aid in mapping the ocean floor Consists of transmitter & receiver Sound waves are sent out, bounce off ocean floor & are reflected back to receiver

SONAR

Features of the Ocean Floor 1. Continental Margins: shallower portions of the ocean floor with thick wedge of sediments a) Continental Shelf: shallow water at the edge of continents & ocean boundary Affected by the rise & fall of sea level b) Continental Slope: steeper slope of the seaward edge of a continental shelf Boundary between continental & oceanic crusts Submarine Canyon: feature carved into continental slope by fast moving currents

Continental Margin

Features of the Ocean Floor 2. Deep Ocean Basin: oceanic crust with a thin layer of sediment a) Trenches: long, narrow deepest features on Earth’s surface b) Abyssal Plain: extremely vast flat areas where the ocean depth is greater than 4 km Covers about ½ the deep ocean basin c) Mid-Ocean Ridges: continuous series of underwater mountain ranges that run along the ocean floors Form when plates pull away from each other d) Sea Mounts: submerged volcanic mountains at least 1000 m high General associated with hot spots If above earth’s surface they form islands (Hawaii) Guyot/Tablemount: volcanic mountain with a flat top

Deep Ocean Basins

Shoreline Features Beach: Area in which sediment is deposited along the shore Beaches and shorelines are constantly undergoing changes as waves and currents act on them Formation beaches and their features is caused by wave refraction: the bending of waves when they reach shallow water

Features of depositional shores Spit Tombolo Barrier island Figure 10-7

Depositional Features Spit: long narrow accumulation of sand with one end attached to the land and the other extending into the sea Tombolo: an island is attached to the mainland by a narrow piece of land such as a spit Barrier Island: long ridge of sand or other sediment deposited or shaped by currents separated from mainland

Barrier island, New Jersey Figure 10-9c

Features of erosional shores Headland Sea arch Sea stack Figure 10-4

Erosional Features Headland: land, high and with a sheer drop, that extends out into a body of water Sea Arch: opening eroded out of a cliff face Sea Stack: blocks of rock isolated from the land by sea. Sea stacks begin as part of a headland. Erosion by waves erodes the softer, weaker parts of a rock first, leaving harder, more resistant rock behind

Sea stack and sea arch, Oregon

Protective Structures Seawalls: built parallel to shore Groins & Jetties: wall like structures built into the water perpendicular to the shoreline in order to trap beach sand Breakwaters: built parallel to shoreline in water in front of beach

Ocean Resources 1. Fresh water a) Needed throughout the world b) Possible to make through distillation, freezing, & reverse osmosis 2. Minerals a) Nodules taken from deep ocean for making steel & other resources b) Petroleum is the most valuable mineral taken from ocean

Ocean Resources 3. Food a) Aquaculture: farming of the ocean b) Now restricted into zones for farming, fishing, recreation, & no touch-no take 4. Ocean-Water Pollution a) Becoming more dangerous as we use harsh chemicals & dump them into the ocean b) BP oil spill controversy estimated between million gallons of oil c) Plastic bottles and bags in oceans