History of Oceanography 4. Twentieth century oceanography.
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History of Oceanography
4
Twentieth century
oceanography
First drilling ship Ship was commissioned by
Germany Set the standard for
multidisciplinary studies of the Ocean.
Mapped the ocean bottom by echo sounding and took multiple depth temperature and salinity readings.
Meteor sailed for 25 months April 1925 to June 1927.
Voyage of the Meteor
Musée océanographic – Europe Scripps institution of Oceanography (1st
institute in U.S.) – California Woods Hole Ocean. Inst. (Boston) Lamont Geological Observatory - New York Rosenstiel school of Marine & Atmosphere
Sciences - Miami Texas A&M University administered The
Ocean Drilling Program
Oceanography gets institutionalized
SCRIPPS
Woods Hole
Lamont
German U-boat led to the invention of the echo sounder to detect submarines.
WW II military performed and supported many studies on transmission of sound in the ocean waves, currents, and ocean- floor topography.
After WW II the U.S. government established a Sea Grant program to fund ocean research.
The expansion of oceanography
The Deep Sea Drilling Project (DSDP) was the 1st large-scale cooperative effort in academic ocean research.
The Glomar Challenger began 1st leg of deep sea drilling.
The deep sea drilling project became the ocean drilling program (ODP).
The ODP drill ship JOIDES Resolution, which is a lot larger than the Glomar Challenger, conducted its first scientific cruise and the JOIDES program continues today.
Large-scale and international oceanographic research
In 1915, Alfred Wegener developed the theory of continental drift. He conceived of a single ancient
landmass called Pangaea that began to break 180 million years ago.
Fredrick Vine and Drummond Matthews provided evidence for sea floor spreading in 1963 They mapped magnetic patterns of
the ocean floor, which showed parallel bands of similarly magnetized reaches on either side of oceanic mountain ranges. Which were records of changes in Earth’s magnetic field over time
The history behind plate tectonic theory
Increased pressure on body cavities and gases dissolved in body tissues limits duration of dives.
Decompressing is necessary at greater depths because rapid ascending turns dissolved gases in tissues into nitrogen. These nitrogen bubbles can stop blood flow. This is know as the bends and is extremely painful illness which can be fatal. To protect oneself, a strict
decompression schedule which includes stopping at different depths
Jim suit allows a person to repair machinery at the ocean floor at surface pressure
Humans invade the deep ocean
William Beebe- descended to a depth of 923 meters off Bermuda in a tethered bathysphere to observe deep-sea life.
Jacques Piccard- designed untethered vessel Trieste – 1960.
Alvin, Sea Cliff- 2 most widely used submersibles.
Japan’s Shinkai- to study microbes in the deep sea .
Submersibles
Trieste (1960)
The bathyscaphe, Trieste, descends to 10,915 meters
Into Marianas Trench
Deepest depth in the ocean
Factors of manned sub: Risk to human life High cost of the systems required Relatively short time that can be spent making
observations Advantages of ROVs (remotely operated vehicles)
No risk to humans Can make computer-assisted maps (based on sonar) Stay down in water for a long time
Autonomous Underwater Vehicles Programmed to carry out specific data gatherings
missions of long durations without human life
Submersibles
A.U.V.s vs. R.O.V.s
Jacques Cousteau- began designing and testing the underwater living chamber in the 1950s
In the 1970s teams lived in undersea chambers for up to 60 days
May be placed on ocean floor or suspended
Can respond and equalize to any pressure
Living under the sea
Invented the aqualung in 1942 with co-inventor Emile Gagnon.
Aquarius
Owned by NOAA and operated by FUI it is located in 60ft of water 4.5 Km off the coast of Key Largo, Florida.
Sometimes the ocean is observed from space; temp., ice cover, color, etc. can all be measured.
Seasat A - 1st dedicated oceanographic satellite. Nimbus 7- mapped phyto-plankton populations. TOPEX/ Poseidon- mapped global sea levels and
obtained data on ocean –atmosphere interaction. Global Positioning system (GPS) - allows ships to
determine their positions to with in a meter
Remote sensing
SEASAT A
TOPEX / POSEIDON
Secchi disk- determines the transparency of water
Core Sampler- takes core samples of sediments
Hydrometer- determines the density of water
Dredge- scoops up marine life
Alvin- famous submarine that explored the deep sea
Terms & Equipment
Side-scan sonar- sonar that can scan in all directions
Current meter- determines the speed and direction of the current
Underwater camera
Flip- a bottle like vessel that can flip sideways in the water
Purse seine net- used to capture schools of fish
Terms & Equipment
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