Download Oceans Sonar Bathymetry Powerpoint

YOU NEED YOUR TEXT BOOKS TODAY. GO GET ‘em
IF YOU DON’T HAVE THEM
JQ: Almost everyone knows that most of the Earth’s
surface is covered in water. Where did all that water
come from?
Bathymetry
• The study of the depth/topography of the
floor of a body of water.
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SONAR
• Short for Sound Navigation and Ranging
• Originally used for submarine detection
during WWII
• Used since to map ocean floor topography
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BATHYMETRY OF THE OCEAN FLOOR
Structures on the ocean floor are mapped by SONAR sound navigation and ranging (echo sounding)
(speed of sound in H20)
depth = time x 1500 meters/sec
2 (round trip)
sea floor
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Do Now: Sound travels at 1500 meters per second in
water. How deep is the ocean bottom if the sonar signal is
received 6 seconds after it was sent?
6 seconds there and back
1500 meters
= 4500 meters deep
1 second
2 trips
Do Now: Sound travels at 1500 meters per second in
water. The Mariana trench is 10,809 meters deep. How
long will it take for sound to travel from the surface of the
water above and back? Show your work.
10,809 m one way 2 R.T
1 second
= 14.4 sec
1500 meters
THE WORLD OCEAN
Covers 71 % of the planet (59.4 % is seafloor)
Divided into major basins –
Atlantic (N & S),Pacific, Arctic, Indian, Southern
*Pacific – largest & deepest
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Continental Margin: the submerged outer edge of a continent
marks the transition between continent and ocean, composed
of shelf, slope & rise
a. continental shelf - underwater extension of the continent, most
biologically productive area because of light availability
b. continental slope – sloping transition between the continent
(granite) and the deep-ocean floor (basalt)
- sediments tumbling down the slope can form turbidity currents
which cut submarine canyons (deep, V-shaped valley running
perpendicular to the shoreline)
c. continental rise – wedge of sediments covering the joint between
ocean crust and continental crust
Continental Margin
NOAA
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Do Now: Sit next to a partner. Have your partner close his
or her eyes. Once they are closed, ask them to make a
click noise or say a sentence. Have them continue to keep
their eyes closed. Then, hold the textbook flat about 5
inches from their face. Ask them to make the same
sounds. Ask them if they can tell if something is near their
face. TEST SUBJECT KEEP EYES CLOSED THE
WHOLE TIME. Experiment, by moving the book farther
away, or to the right or left, and ask them if they can
describe the position/distance.
Ocean Basin Features:
a. abyssal plain - flat, featureless region similar to a desert; common in Atlantic
and Indian Oceans, rare in the Pacific
b. abyssal hill - occur where sediment is not thick enough to cover
the underlying rock completely. Usually extinct volcanoes or small
formations of rock once extruded in molten form.
c. seamount - peaks of volcanic mountains (sea mountains, completely underwater)
d. guyot - submerged, inactive volcano flattened by erosion; like
e. island - seamounts extending out of the water. They differ from continents
because they have no margins.
f. trenches – arc-shaped depression in the deep-ocean floor with very steep
sides and flat sediment-filled bottoms, associated with subduction zones where
ocean crust is being recycled into the mantle
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Mt. Everest, at 29,000 ft., could fit into
the Mariana trench and still be 7,000
ft. below sea level.
g. MOR - 40,000 mile long mountain range
where new oceanic floor is being formed.
Divergent plate boundaries are found in all
parts of the ocean - not just in the middle of
the Atlantic.
NOAA
Iceland is a large section of the
MOR extending above the water.
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JQ: Do any organisms use sonar? Explain
Also called Bio Sonar, many dolphins, toothed-whales, cave swiftlets, shrews, tenrecs
Link
Link
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