Explorers
Alfred Wegener
Mesosaurus Fresh water reptile Permian Period 286-245 million years ago South America, Africa Approximately 16 inches long
Glossopteris Plant fossil Permian Period 286-245 million years ago These specimens were found in Australia.
Name means Dog Jaw Small carnivores mammals descended Early Triassic 240 million years ago Found in:africa, South America Approximately 6 feet long Cynognathus
Lystrosaurus Shovel reptile Land dwelling Early Triassic 240 million years ago Adults about 100 cm long
Harry Hess
Bathymetric Profiling
Harry Hess s Concept of Sea Floor Spreading
Heat flow at a mid-ocean ridge
Measuring Earth s magnetic field Fig 3.24 a
Gravitational Differences Dikes are more compact and dense than lava flows, so the force of gravity is very slightly greater above zones where numerous dikes, or swarms as geologists call them, are concentrated. The gravimeter mounted in Alvin can measure these small changes in gravity and map out the pattern of shallow dikes under the axis.
Bathymetric (Elevation) Map
Maurice Ewing
Marie Tharp
Bruce Heezen
Jacques Piccard and Donald Walsh In 1960, Swiss scientist Jacques Piccard (above in this photo) and Navy lieutenant Donald Walsh made history when they descended in the U.S. Navy bathyscaphe Trieste to the bottom of the Mariana Trench. The brave divers were housed in a sphere attached to the bottom of the bathyscaphe's long buoyant tank. http://images.google.com/images?gbv=2&svnum=10&hl=en&ie=iso-8859-1&q=%22jacques+piccard%22
Trenches
The Trieste http://www.onr.navy.mil/focus/ocean/vessels/submersibles5.htm http://bjsonline.com/watches/articles/0022_3.shtml
Fred Vine and Drummond Matthews Fred Vine
Magnetic Reversals Preserved in Lava Flows
Magnetic stripes and Magnetic Reversals
High Intensity (+) Low Intensity (-)
Are we due for a reversal?
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The Joides Resolution and Glomar Challenger Drilling on board the Resolution continues day and night. From top to bottom: drilling derrick, drill bit, re-entry cone, and a retrieved core. (Photographs courtesy JOI Alliance/IODP Researchers study a freshly recovered sediment core inside one of the science labs on board the Resolution. (Photograph courtesy JOI Alliance/IODP http://earthobservatory.nasa.gov/study/paleoclimatology_sedimentcores/
Fig 4.10 Age of the Sea Floor
J. Tuzo Wilson
Hot Spots The Hawaiian- Emperor Seamount Chain
Driving Mechanisms 2. Mantle Convection
Seismic Tomography and Models of Mantle Convection
Blue cool, yellow hot
Woods Hole Oceanographic Institution
The Lulu and Atlantis
The Alvin Woods Hole Oceanographic Institution : Alvin Disassembly Movies : View Video (Quicktime)
Hydrothermal Vents Finding New Life http://www.ocean.udel.edu/deepsea/leve l-1/geology/smoker.mov
Hydrothermal Vents http://link.brightcove.com/services/link/bcpid687239786//bctid736245369
Hydrothermal Vents 1. Cold water seeps into the ocean floor 2. Heated water mixes with Earth s crust picking up dissolved metals like iron, zinc and copper; oxygen is removed and the water becomes acidic. 3. The heated water rises 4. The fluids exit the chimney and mix with ocean water. The metals mix with sulfur to become metal sulfides giving making the smoke look black 5. In white smokers silica remains mixed in the hydrothermal fluids and precipitate out. Another chemical reaction creates anhydrite. These two minerals make the smoke look white.
Life at Hydrothermal Vents
Vents Around the World
To support their global research, Lamont-Doherty scientists operate the worldranging, 235-foot research vessel, Marcus G. Langseth. The ship collects gravity and magnetics data on the seafloor; creates seismic images of rock layers below the ocean floor; dredges rock samples; takes ocean-floor sediment cores; maps the ocean floor with sonar; and collects water samples to explore ocean currents, temperature, salinity, marine life and other data for a wide range of oceanographic research.