Download exploring the ocean floor - Brighten Academy​Middle School

EXPLORING THE OCEAN FLOOR
http://www.pbs.org/wgbh/nova/alicia/submersibles.html
Difficulty in exploring the ocean
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Sunlight does not penetrate far below the surface.
Water is very cold.
Tremendous pressure.
Technology Used To Study Ocean Bathymetry
http://www.youtube.com/watch?v=-fAAxEIFeLU
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Bathymetry: measurement of
ocean depths and the charting of
the shape or topography of the
ocean floor.
Echo Soundings (sonar):
measuring the time it takes for
the echoes to return to
determine depth and shape of
the ocean floor.
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Multibeam and side-scan sonar
give a more detailed image of the
ocean floor.
Satellites: measures the
variations of ocean surface
elevation which is caused by
gravitational attraction and
mimics the shape of the
ocean floor.
Features of the Ocean Floor
Ocean Floor Can Be Divided Into 3 Major
Provinces
• Continental Margins: shallow
water areas close to the
continents
• Deep Ocean Basins: deep
water areas farther from land.
• Mid-Ocean Ridge: shallower
areas near the middle of an
ocean.
Continental Margin
Continental Shelf
• Gently sloping, shallow
area of the ocean floor.
• Extends from the shore
beneath the ocean surface
to a point where there is
an increase in the slop
(shelf break).
• Flat and Featureless
• Made of Granitic
continental crust
Continental Slope
• Lies beyond the
shelf break.
• Where the deep
ocean basin begins.
• Contains submarine
canyons. The
Atlantic Ocean has
many submarine
canyons along its
coast.
Continental Rise
• Transition zone between the
continental margin and the
deep ocean floor.
• Comprised of a huge pile of
debris.
Deep Ocean Basin
Abyssal Plains
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Flat or gently sloping areas of the
deep ocean basin floor.
Extends from the base of the
continental rise into deep ocean
basins.
Among Earth’s flattest and
smoothest regions an the least
explored.
Formed by particles of sediment
slowly drifting onto the deep ocean
floor.
Most abyssal plains occur in the
Atlantic and Indian oceans.
Cover about 40% of the ocean floor
Depths from 2,200 to 5,500 meters.
Seamount
• Mountain that does not
reach the water’s
surface.
• Formed from extinct
volcanoes.
• If they have flattened
tops they are called
guyots.
Ocean Trenches
• Occurs at convergent
boundaries.
• May produce volcanic
island arcs or volcanic
mountain ranges.
• Contains the deepest
part of the world’s
oceans (Mariana Trench).
• Most are formed in the
Pacific Ocean.
Mid-Ocean Ridge
• Mountain range that extends
through all ocean basins.
• Earth’s largest mountain chain.
• Covers 23% of Earth’s surface.
• Entirely volcanic and composed
of basaltic oceanic crust.
• Rift Valley: created by sea floor
spreading
• Hydrothermal Vents: Hot springs
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Warm water vents
White Smokers
Black Smokers
Mid Ocean Ridge
OCEANS REVIEW http://www.purposegames.com/game/the-world-oceans-quiz-quiz
OCEAN FLOOR QUIZ http://www.onr.navy.mil/focus/ocean/regions/oceanfloor1.html
Types of Coral Reefs
• Fringing Reef: directly
attached to the shore
of an island.
• Barrier Reef: separated
from nearby landmass
by open water.
• Atoll: ring shaped coral
reef growing upward
from a submerged
volcanic peak.
HTTP://GPB.PBSLEARNINGMEDIA.ORG/
RESOURCE/NSN09.SCI.LIFE.ECO.SEAFLO
OR/EXPLORING-THE-ARCTICSEAFLOOR/