Ocean Topography

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• Ocean Topography

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What is Ocean Topography?

• The shapes, patterns and physical configuration
  of the ocean surface.

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• Side-scan sonar is used to create an image of
  large areas of the ocean floor.
• This tool is used for mapping the seabed.
• In conjunction with seafloor samples it is able
  to show differences in material and texture type
  of the seabed.

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Ocean Basin Structures

• 1.Continental Margin Continental Shelf
• (near continent) Continental Slope
• Continental Rise
• Submarine Canyons
• 2. Deep Ocean Basin Abyssal Plains
• Oceanic Ridges
• 3. Others Trenches
• Seamounts Guyots
• Atolls

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Definitions

• Continental Shelf
• An extension of the continent under water. There
  is a fairly abrupt drop off at the edge.
• Has hills, valleys, canyons and other features.
  
• This is very wide off of Atlantic Canada.
• Grand Banks Scotian Shelf

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• Continental Slope
• The portion of the ocean bed between the edge of
  the continental shelf and the deep-sea floor.
  The average angle displayed by the slope is about
  5 degrees.
• Abyssal Plain
• The largest portion of the earths sea bed. It
  is covered with a thick layer of sediment,
  beneath which is relatively dense basalt rock.
  Vast, empty and usually boring.

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• Seamounts and Guyots
• Both are underwater volcanic mountains that
  originated at a hotspot or along a ridge.
• Guyots have reached the surface of the ocean
  and have flat, eroded tops.
• Seamounts have never reached the surface, so
  they have pointy tops.

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Example Hawaii
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• Submarine Canyons
• V-shaped indentations in the continental shelf,
  usually ending in a fan shaped wedge of
  sediments.
• How do submarine canyons form?
• Fast moving currents and underwater landslides.

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The Gully

• Submarine canyon off Nova Scotia
• Marine Protected Area (MPA) because of the rare
  corals found there a resident population of
  approximately 280 Northern Bottlenose Whales.
• The natural gas pipeline goes right by
  itproblems?

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• A large underwater mountain chain.
• Part of a vast system extending some 40,000
  miles through four of the worlds oceans.
• Caused by divergent plate boundaries.

Mid-Ocean Ridge
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Mid-Atlantic Ridge
NS
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• Trench
• Deep gap in ocean floor, formed by movement of
  plates.
• Eg
• Mariana Trench is 10,668 meters deep
• Deepest areas of the Earths crust.
• 90 of trenches are found around the Pacific rim.

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Atolls

• A ring shaped island of coral reefs and coral
  debris. These often form over sinking inactive
  volcanoes.

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Major Sea Floor Structures
H
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Major Sea Floor Structures
A. Continental Slope
D. Mid Ocean Ridge
E. Island
F. Continental Shelf
B.Sea Mount
C. Abyssal Plain
G. Oceanic Trench
H. Guyot
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