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The Ocean Floor Beginnings of the Plate Tectonic theory. Cape Arago State Park, Oregon. Mapping the Oceans : Echo sounding (since the 1920s) Multibeam sonar (today) - Speed of sound in water = 1500 m/s - Relatively complete map, yet low resolution. Mapping the Oceans :
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The Ocean Floor Beginnings of the Plate Tectonic theory Cape Arago State Park, Oregon
Mapping the Oceans: Echo sounding(since the 1920s)Multibeam sonar(today) - Speed of sound in water = 1500 m/s - Relatively complete map, yet low resolution
Mapping the Oceans: Using the sonar methods, oceanographers have separated the ocean floor into three main components: 1. continental margins 2. deep-ocean basins 3. mid-ocean ridges
Continental Margins: Passive continental margin
Continental Margins: Passive continental margin : Sandy beaches
Continental Margins: Passive continental margin: Longshore drift
Continental Margins: Passive continental margin : Longshore drift of Cape Cod
Continental Margins: Passive continental margin
Continental Margins: Passive continental margin
Continental Margins: Active continental margin
Deep-Ocean Basins: Trenches and Abyssal Plains
Coral Reefs and Atolls: Effect of submerged oceanic island volcanoes Only in tropical regions (warm water)
Mid-Ocean Ridges: Some of the tallest mountains on Earth, just submerged
Mid-Ocean Ridges: Ocean crust is composed of basaltic igneous rocks. These are “pillows” of lava solidified under water. These form the top part of the ocean crust.
Mid-Ocean Ridges: Ocean crust is composed of basaltic igneous rocks. These are “pillows” of lava solidified under water. These form the top part of the ocean crust.
Mid-Ocean Ridges: and the associated oceanic crust
The Ocean Ridge - Trench System The World Ocean illustrates something about tectonics