Transcript oceans - TeacherWeb

OCEANIC Lithosphere
PREDICT: What percent of the earth is
covered in water? What percent is land?
Explain your prediction.
PREDICT:What percent of the earth’s
water is salt? What percent is fresh?
Explain your prediction.
World Ocean Facts
Atlantic
Ocean
Pacific
Ocean
Indian
Ocean
Arctic
Ocean
Area
(1,000,000
km²)
Volume
(1,000,000
km³)
Average
Depth
(m)
Maximum
Depth
(m)
82.4
323.6
3926
9200
165.2
707.6
4282
11,022
73.4
291.0
3963
7460
14.1
17.0
1205
4300
Features of the Ocean Floor
Salinity
• A measure of the amount of dissolved
salts in a given amount of liquid
Estuary
• A place where fresh & salt water meet.
shoreline
• The point where land meets the water
Continental shelf
• Sloping shelf of land that is made of the
edges of the continent
• The continental shelf regions also contain
the highest amount of benthic life
(plants and animals that live on the ocean
floor).
Continental Edge
• The part of the continental shelf that
begins to angle sharply down
Continental Slope
• The steep cliff like drop from the
continental edge to the ocean floor that
connects the continental shelf and the
oceanic crust
• It usually begins at 430 feet (130 meters)
depth and can be up to 20 km wide.
Continental rise
• Lower part of the continental slope which
extends to the ocean floor
Abyssal Plain
• The broad flat ocean bottom
Trenches
• Deepest parts of the ocean created by the
undersea rivers and currents
• The deepest one, the Marianas Trench in
the South Pacific Ocean, is more than
35,000 feet (10,668 meters), or almost
6.6 miles (10.6 kilometers) deep.
Mid-Ocean Ridge
• A chain of mountains under the sea
• The world’s longest mountain range. It
runs almost unbroken for 40,000 miles.
Rift Valley
• Large crack that runs down the middle of
the Mid-Ocean Ridge
Seamounts
• An underwater mountain formed by a
volcano
• Most seamounts began life as volcanoes
formed over hot spots in the ocean floor.
After the crust moves off the hot spot, the
volcanic activity stops.
Guyots
• Seamounts whose peaks have eroded and
become a flat surface are called guyots
• Inactive volcanoes on the ocean floor
Atoll
• As the seamount sinks or its peak erodes,
the seamount will disappear beneath the
water leaving the coral ring. This is called
an atoll.