* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Oceanic Topography
Survey
Document related concepts
Marine debris wikipedia , lookup
Oceanic trench wikipedia , lookup
History of research ships wikipedia , lookup
Challenger expedition wikipedia , lookup
Marine pollution wikipedia , lookup
Southern Ocean wikipedia , lookup
Marine biology wikipedia , lookup
Indian Ocean Research Group wikipedia , lookup
Pacific Ocean wikipedia , lookup
Anoxic event wikipedia , lookup
Ecosystem of the North Pacific Subtropical Gyre wikipedia , lookup
Ocean acidification wikipedia , lookup
Indian Ocean wikipedia , lookup
Arctic Ocean wikipedia , lookup
Marine habitats wikipedia , lookup
Effects of global warming on oceans wikipedia , lookup
Transcript
OCEANIC TOPOGRAPHY By Greg Schwab May 7, 2007 Competency 39 • The teacher understands structure and function of the hydrosphere 39.9 • The beginning teacher identifies the characteristics of different ocean zones (e.g., coastal, lighted, deep, estuaries, bays). TEKS: Geology, Meteorology, Oceanography • (11) The student knows characteristics of • • oceans. The student is expected to: (11A) Identify physical characteristics of ocean water including salinity, heat capacity, colligative properties, and density. (11C) Compare the topography of the ocean floor to the topography of the continents. Word Wall Continental Shelf Continental Slope Continental Rise Oceanic Basin Oceanic Ridges Oceanic Trenches Seamount Guyout Atoll Volcanic Island Arc Bathymetric Continental Shelf A feature of the ocean floor; the flooded margins of the continents that form a zone of relatively shallow water adjacent to the continents Characteristics of the shelf • Considered part of the continent not the ocean • Slopes gently away from land for an average of • • • 75km (47 miles) Average water depth is 130 m (425 ft) Much wider on some parts of the continents than other parts Retains features of the adjacent land that is above water Continental Slope A feature of the ocean floor; a steep slope forming the transition between the continental shelf and the deep ocean basin. Characteristics of the slope • Transition between the continent and the deep ocean basin • Water depth ranges from 120 m (390 ft) to 3,000 m (10,000 ft) • Width of the slope is 20-40 km (12-25 miles) • Steeper than the shelf • Some slopes have submarine canyons Submarine Canyons • Long deep-sided trenches extending from the top of the slope to the ocean basin • Can be similar in size and depth to the Grand Canyon • Believe to been formed by turbidity currents (a muddy current produced by underwater landslides) Continental Rise The Transitional area of the continental margin between the continental slope and the abyssal plain. Characteristics of rise • Less steep than continental slope • Created mainly by sediment deposits from turbidity currents flowing down submarine canyons. Continental Margin Composed of the continental shelf, continental slope, and continental rise. North American East Coast North American Gulf Coast North American East Coast North American West Coast North American West Coast Ocean Basin The deep bottom of the ocean floor, which starts beyond the continental slope. Characteristics of the Basin • Deepest part of the ocean floor • Under 4-6 km (2-4 miles) of seawater • Features include: Abyssal plain, Oceanic ridges, Oceanic trenches, and Seamounts • Ocean basin and ridges cover more than half the earth’s surface • More surface area than all of the land continents Abyssal Plain The practically level plain of the ocean basin. • Covers an area equal to the continental land mass Oceanic Ridges Long, high, continuous, sub-oceanic mountain chains; for example, the MidAtlantic Ridge in the center of the Atlantic Ocean Basin Characteristics of ridges • Part of a chain of mountains that are 84,000 km long • Mid-Atlantic Ridge is longest mountain chain on earth • Ridges are spreading centers or divergent plate boundaries where new ocean floor is created Oceanic Trenches Long, narrow, deep troughs with steep sides that run parallel to the edge of continents Characteristics of trenches • Extend 8-11 km below sea level • Long narrow basins • Develop adjacent to subduction zones • Zone of convergence • Form parallel to continents Seamounts Steep submerged volcanic peaks on the abyssal plain. Characteristics of seamounts • More than 10,000 scatter the ocean basin • By definition rise more than 1 km (0.6 miles) above the ocean floor. • Can extend above sea level (called an island) • Most Pacific Basin islands are seamounts. Guyout • A flat topped seamount which has subsided beneath the water’s surface because of wave action. Atoll Volcanic Island Arcs • Curving Chains of volcanic islands that occur over belts of deep-seated earthquakes • For example the Aleutian Islands are volcanic island arcs, formed over the Aleutian oceanic trench Bathymetric • Measurement of depths of the oceans; also the data derived from such measurement, especially as compiled in a topographic map. Exploring the Ocean Floor • Challenging at best • Single soundings • Sonar (single beam) • Multibeam sonar • Sidescan Sonar • Satellite surface water topography Ocean Topography Quiz • 1. Most seamount islands are found in the ___________ Ocean Basin. • 2. T/F Volcanic Island arcs are associated with subduction zones in zones of convergence? • 3. In ocean basins, the youngest crust material would be found closest to or farthest from the oceanic ridge? Ocean Topography Quiz • 4. Submarine canyons are associated with what part of the ocean’s topography? • 5. The continental shelf is an extension of the __________? • 6. What is the longest mountain chain on earth? Ocean Topography Quiz • 7. For the North American Continent, the continental slope would be steeper on the east or west coast? • 8. The best surfing would be on the west or east coast of North America? • 9. The most accessible beaches in North America would be on the west or east coast?