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