the ocean floor. studying the ocean floor risky to explore ocean floor ways to survey include: sonar...
TRANSCRIPT
Studying the Ocean Floor
• Risky to explore ocean floor
Ways to survey include:• Sonar• SatelliteWays to explore:• Alvin• Deep Flight• Jason II & Medea
Sonar
• Sound Navigation And Ranging
• Sends pulses from a ship down into ocean… bounces off bottom and returns pulse back to ship
• Deeper water = longer pulse response
Satellite
• Seasat – satellite took images that allowed us to measure direction and speed of ocean currents
• Geosat – measures changes in height of ocean’s surface
• Used be top-secret• Now used to make ocean
maps
Regions of Ocean Floor• Ocean floor is not flat• Many features:• Rift valley, mid-ocean
ridge, seamounts, and trenches
• Continental Shelf, C. Slope, C. Rise, and Abyssal Plain
Regions of Ocean Floor• Continental shelf – begins at
shoreline and slopes gently toward open ocean. Continues until ocean floor begins to slope more steeply downward Depth can reach 200m
• Continental Slope – begins at edge of continental shelf. Continues down to flattest part of ocean floor. 200m – 4000m
Regions of Ocean Floor• Continental Rise – the base
of the C. Slope, is made of large piles of sediment. The boundary between the continental margin and the deep-ocean basin lies underneath the continental rise.
• Abyssal Plain – the broad, flat part of the deep-ocean basin. It is covered by mud and the remains of tiny marine organisms. The avg depth is 4000m.
Exploring Ocean
• Piloted Vessels:• Alvin: - 7m long- Can reach deepest parts
of ocean- Used to find sunken
ships; lost H bomb- Found life near
hydrothermal vents near Galapagos.
Exploring Ocean• Piloted Vessels:• Deep Flight: - underwater airplane- Goal is to one day dive
11,000m deep.• Robotic Vessels: Jason II
and Medea- Reduce costs w/out pilot- Can withstand high
pressure
Marine Life• Three main groups :- Plankton (microscopic
floaters){Zoo (animal) and Phyto(Plant)}- Nekon (swimming
organisms) – mammals and fish
- Benthos (live at bottom) – crabs, starfish, worms, coral, sponges, seaweed, and clams
Benthic Environment
• Bottom environment• Region near ocean floor
and all the organisms live on or in it
• Zones Include:• Intertidal, Sublittoral,
Baythal, Abyssal, and Hadal
• I’m Sure Being A Handful!
Pelagic Environment• Zone near the ocean’s
surface and at middle depths
• Beyond Sublittoral Zone and above Abyssal Zone
• Two Major Zones: Neritic and Oceanic Zone