Continental Margins & Ocean Basins. Bathymetry: The Study of Ocean Floor Contours. Early bathymetric studies were often performed using a weighted line to measure the depth of the ocean floor. Advances in Bathymetry Echo sounding Multibeam Systems Satellite Altimetry.
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Early bathymetric studies were often performed using a weighted line to measure the depth of the ocean floor.
Advances in Bathymetry
What are the two classifications of ocean floor?
Continental Margins – the submerged outer edge of a continent
Ocean Basin – the deep seafloor beyond the continental margin
shallow, submerged edge of the continent.
abrupt transition from continental shelf to the continental slope.
transition between the continental shelf & the deep-ocean floor.
accumulated sediment found at the base of the continental slope.
river erosion during previous glaciation periods
turbidity currents: rapid movement of a mass of sediment down a slope
often caused by earthquakes
An oceanic ridge is a mountainous chain of young, basaltic rock at an active spreading center of an ocean.
hydrothermal vents: spring of hot, mineral- and gas-rich seawater
near seafloor spreading centers
- 1977, Robert Ballard & J. Grassle in Alvin, at 3000 m
near the Galápagos Islands
Hydrothermal vents are sites where superheated water containing dissolved minerals & gases escapes through fissures, or vents.
Seamounts are volcanic projections from the ocean floor that do not rise above sea level. Flat-topped seamounts eroded by wave action are called guyots.
Abyssal hills are flat areas of sediment-covered ocean floor found between the continental margins & oceanic ridges. Abyssal hills are small, extinct volcanoes or rock intrusions near the oceanic ridges.
Trenches are depressions in the ocean floor caused by the subduction of a converging ocean plate.
Island Arcs, chains of volcanic islands & seamounts, are usually found parallel to the edges of ocean trenches.
(left) As two oceanic plates converge, an island arc is formed by volcanic activity.
© 2002 Brooks/Cole, a division of Thomson Learning, Inc.
abyssal plains: flat, featureless expanses of seafloor
covered w/ sediment
between continental margins & oceanic ridges
why so flat?