Features of the Ocean Floor (Bathymetry)
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Transcript of Features of the Ocean Floor (Bathymetry)
Features of the Ocean Floor(Bathymetry)
http://www.ngdc.noaa.gov/mgg/image/2minrelief.html
HMS Challenger
• http://www.wshs.fcps.k12.va.us/academic/science/bjewell/ocean/hhocean/final/chall.htm
• 1st major scientific study of the oceans •Determined depth by dropping a weighted line
SONAR • Sound Navigation and Ranging
• Provides a quick way of looking through water to identify features in and under the water (fish, sandbars, etc.)
P(ic)assow
Modern Technology• Multi-beam systems
– 120 beams of echo sounders– “mowing the lawn”
• Satellite altimetry– Not measured directly– Measures changes in elevation
of water using satellites
http://marine.usgs.gov/fact-sheets/fs172-97/mapping.html
1. Continental Shelf– Submerged edge of
continent– Gentle slope away from
shore– Resources!
(Gas, oil, gravel, fishing!)
2. Continental Slope– Steep!– Transition from shelf to
deep ocean floor
3. Continental Rise– Medium steep...– Sediment that collects
at bottom of slope
Continental Margin
http://oceanexplorer.noaa.gov/explorations/islands01/log/sep28/media/sab_habitats.html
Submarine Canyons• Cut into continental shelf & slope!• Caused by earthquakes
http://oceanexplorer.noaa.gov/explorations/deepeast01/background/dumping/media/dumping1.html
Ocean Basin Floor1. Deep-Ocean Trenches
– Subduction zones– Super deep! (<10,000m)
2. Abyssal Plains– Flattest Places on Earth!– Covered in sediment
3. Seamounts– Submerged
volcanoes4. Guyots
– Inactive Seamounts– Flat top from wave
erosion
http://www.mbari.org/news/news_releases/2004/agu2004.html
Ocean Ridges• Divergent plate boundary• Mountainous chain of young
volcanic rock• Site of hydrothermal vents
Atolls• Ring-shaped islands of coral
reefs• Form on submerged inactive
volcanoes
Research Vessels
Meteor
http://www.photolib.noaa.gov/ships/ship3023.htm
Atlantis
www.whoi.edu
Trieste
http://www.onr.navy.mil/focus/ocean/vessels/submersibles4.htm
“ALVIN”http://www.comptons.com/encyclopedia/CAPTIONS/18005895_P.html
JOIDES Resolution
http://www-odp.tamu.edu/resolutn.html
Glomar Challenger
http://pubs.usgs.gov/publications/text/glomar.html