The Marine Environment
Exploration of the OceanOceanography:
Oceanographers: study the ocean & its floor up to 6.4 km into the ocean floorOcean floor: is made up of continental & oceanic
crustSubmersibles: underwater research vessels
Help oceanographers study the ocean depthsBathysphere: early type of submersible used
for deep-ocean diving Remained connected to the research ship for
communication & life support
SubmersiblesBathyscaph: self-propelled, free-moving
submarine used for deep-ocean divingCan hold one pilot & 2 scientistsHas made new discoveries where life was
thought to be non-existantRobot submersibles: enable oceanographers
to study the ocean at great depths & long periods of time
SONAR: SOund Navigation And RangingAid in mapping the ocean floorConsists of transmitter & receiverSound waves are sent out, bounce off
ocean floor & are reflected back to receiver
SONAR
Features of the Ocean Floor1. 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 Floor2. Deep Ocean Basin: oceanic crust with a thin layer
of sedimenta) 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 FeaturesBeach: Area in which
sediment is deposited along the shoreBeaches 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 shoresSpitTomboloBarrier island
Figure 10-7
Depositional FeaturesSpit: 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 shoresHeadlandSea archSea stack
Figure 10-4
Erosional FeaturesHeadland: 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 StructuresSeawalls: built
parallel to shoreGroins & 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 Resources1. Fresh water
a) Needed throughout the worldb) Possible to make through distillation,
freezing, & reverse osmosis
2. Mineralsa) Nodules taken from deep ocean for making
steel & other resourcesb) Petroleum is the most valuable mineral taken
from ocean
Ocean Resources3. Food
a) Aquaculture: farming of the oceanb) Now restricted into zones for farming, fishing,
recreation, & no touch-no take
4. Ocean-Water Pollutiona) Becoming more dangerous as we use harsh
chemicals & dump them into the oceanb) BP oil spill controversy estimated between 90-
180 million gallons of oilc) Plastic bottles and bags in oceans