Includes iClicker Questions Notes from each Chapter Diagrams and HW Questions OCE1001 Final Study Guide Chapters 3 4 12 13 Chapter 3 Bathymetry Measures the vertical distance from the ocean surface to mountains valleys plains and other sea floor features How bathymetry is measured Soundings Poseidonus was the first sounding in 85 b c Line with heavy weight which was used for 2000 years The unit of measure it used is a called a fathom The sea floor can be mapped from space using satellite measurements Measures features based on gravitational bulges in the sea surface Which indirectly reveals bathymetry Ancient Bathymetry is measured using Seismic Reflection Profiles such as air guns and strong low frequency sounds These tools show details of the ocean structure beneath the sea floor Hypographic Curve shows the relationship between height of land and the depth of the ocean 70 8 of Earth is covered with oceans Average ocean depth is 3729 meters Average land elevation is 840 meters The Three major Ocean Provinces Continental margins Shallow water areas close to the shore Deep Ocean basins Deep water areas farther from land Mid Ocean Ridge Submarine mountain range Continental Margins Passive or Active Passive Not close to any plate boundary no major tectonic activity One example would be the East coast of the US Active Has to do with convergent or transform plate boundaries A good amount of tectonic activity The features of a Continental Margin Continental shelf Shelf break Continental slope Continental rise Passive Continental Margin Continental Shelf flat zone from shore to the shelf break Shelf Break is where marked increase in slope angle occurs The continental shelf is part of a continent and its acerage width is 70km but can extend to 1500km And the average shelf break is 135m The type of continental margin determines the shelf features Passive margins have wider shelves California s transform margin has a continental borderland which is a series of generally northwest trending basins and ridges some of which extend above sea level as the Channel Islands Continental Slope Where deep ocean basins begin The topography is similar to mountain ranges on land It is marked by submarine canyons Submarine Canyons are narrow deep and v shaped Steep to overhanging walls Extend to the base of a continental slope and it is 3500m below sea level It is shaped by turbidity currents Turbidity Currents underwater avanlances mized with rocks and other debris Sediment comes from the continental shelf The sediment moves by gravity and they are deposited at the slope base Continental Rise is the transition between continental crust and oceanic crust It is marked by turbidite deposits Graded bedding in trubidit deposits Deposits generate deep sea fans or submarine fans Distal ends of submarine fans become flat abyssal plains Abyssal plan volcanic peaks pole through sediment cover Below the sea level are seamounts tablemounts or guyots at least 1km above sea floor Above the sea level are volcanic islands Active continetal margins are either Convergent or Transform Convergent Active Margin consist of Narrow shelf Active continental volcanoes Offshore trench Oceanic continent convergent plate boundaries An example of this would be Western Africa Transform Continental Margins are less common Transform plate boundaries Linear islands banks and deep basins close to shore An example of this would be Coastal California along the San Andreas Fault Bathymetric Contour Passive Margin Bathymetric Contour Active Margin Convergent margins generate ocean trenches Ocean Trenches Deepest part of oceans Pacific Ocean has the most Deepest is Mariana Trench at 11 022 Volcanic arc on non sub ducted ocean plate May produce island arc Japan It is considered a continental arc on land Pacific Ring of Fire are margins of the Pacific ocean and marked by convergent boundaries and hold the majority of the world s active volcanoes and earthquakes The Mid Ocean Ridge is the longest mountain chain and it is 2 5km above the surrounding sea floor Features Wholly volcanic Basaltic lava and it is a divergent plate boundary Central rift valley down dropped by seafloor spreading Seamounts are tall volcanoes Pillow lava or Pillow basalt are the shapes formed when hot basaltic lava quickly cools The Johnson Sea Link is a submersible that is driven by a human and battery operated Remotely Operated Vehicles are operated with electric power and telecom through an umbilical cord with no human and no limit on bottom time Ocean Observations is to establish permanent instrument nodes on a fiber optic network The biggest proposal is the Neptune Project Precipitating minerals give vent fluids different colored smoky appearances If they fall out of vent fluids they form chimneys and other formations on the sea floor Chapter 4 Marine Sediments are eroded rock particles and fragments transported to the ocean and Oceanographers decipher Earth history through studying sediments Paleoceanopgrahy is the study of how the ocean atmosphere and land interactions have produced changes in ocean chemistry circulation neology and climate Sediment Classification Lithogenous or Terrigenous derived from rocks on land Biogenous derived from organisms Hydrogenous or Authigenic derived from water Cosmogenous derived from outer space Lithogenous sediments also called terrigenous Eroded rock fragments from land Reflect composition of rock from which derived Produced by weathering which is the breaking of rocks into smaller pieces Small particles eroded and transported to the ocean by streams wind glaciers and gravity Greatest amount of these found around continental margins Bigger sediments are closer to shore Smaller ones are farther from shore It is mainly mineral quartz Seafloor spreading and sediment accumulation Sediment of continental shelves Neritic sediment contains mostly terrigenous material Sediment of continental slope rise and deep ocean floors Pelagic sediments contain greater proportion of biogenous material Calcium Cabonate Compensation Depth CCD CO2 saturation decreases with lower temp and higher pressure Above the CCD is Calcarious ooze Below the CCS is Silicious ooze Calcarious Foraminiferans Coccolithophores are also called nannoplankton and it is photosynthetic algae Coccoliths are individual plates from dead organisms Rock chalk is lithified coccolithrich ooze Abyssal Plains extend from the base of a continental rise and sediments cover ocean crust
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