Marine Geology

Document Sample
Marine Geology Powered By Docstoc
					             Marine Geology
• Study character and history of earth below
  and within the oceans:
  – atmosphere  core
  – beach  deep-sea
  – igneous and sedimentary rocks
     • Most sedimentary rocks deposited in the ocean
     • Many igneous rocks produced in marine
       environments (ocean crust)
             Marine Geology
• UF is a member of the Consortium for Ocean
  – Formerly Joint Oceanographic Institutions- UF, Scripps,
    Lamont, WHOI, OSU, UW, URI, USF, FSU, Univ.
    Miami, Rutgers, UCSC, Penn State, Stanford, UH, Texas
    A&M, UT Austin, U Mich, U. Neb., MBARI

  – “a consortium of U.S. academic institutions which brings
    to bear the collective capabilities of the individual
    oceanographic institutions on research planning and
    management of the ocean sciences”

  – US entity that manages the Integrated Ocean Drilling
    Program (IODP)
            Marine Geology
• Course plan
  – Build the ocean basins
  – Add the water
  – Circulate the water
  – Add the sediments
  – Add fluids within rocks/sediments
  – Record of past history
  (reading assignments)
    History of Marine Geology
• Phoenicians and Cretans (1200 BC)- trade within
  the Mediterranean
• Greeks (900-700 BC)- sailed out Straits of
  Gilbralter- thought they were in a large river
• Polynesians – By 300-600 AD on all inhabitable
  islands, up to Hawaii
• Columbus- 1492- thought earth’s circumference
  half its size (Ptolemy)
     History of Marine Geology
• Magellan (early 1500’s) tried to take depth
  soundings. First circumnavigation
• Beyond voyages of discovery (navigation,
  trade routes) and exploitation
• Cook (~1770’s; Endeavour,
Resolution, Adventure, Discovery)
- largely exploration/foreign relations,
- but kept very accurate records
   - Chronometer (latitude)
   – Collected biological and geological
     History of Marine Geology
• US Exploring Expedition (1838-42) (Naval
   – Poor leadership (Wilkes), 4 yr voyage, explored east
     coast AA, Hawaii, collected specimens and artifacts
     (Smithsonian), search for “polar hole”
   – 19 volumes of maps, comments and illustrations
• Matthew Maury (1847)
   – US Navy Bureau of Charts and Instruments
   – Compiled data on winds and currents from ships’ logs
     (“father of physical oceanography”)
   – Determined global patterns of surface winds and
             Challenger Expedition

•Challenger Expedition
  –First expedition devoted to
  marine science
  –Funded by Royal Society of
  London (Thomson)
  –Mission: to study “the
  conditions of the deep sea
  throughout all of the great
  ocean basins”

      Journal page, Lt. Aldrich
Challenger Expedition
         Challenger Expedition
• 500 soundings (steel cable)
   – Deepest = 8180 m in Mariana Trench
   – Deep-sea topography
• 133 dredges
   – Discovered 715 new genera and 4500 new species
   – Disproved Forbes’ theory that there was no life below
     600 m (high pressure, no oxygen or light )
   – Discovered manganese nodules and sediment
• Collected temperature, salinity and water density
• Produced 50 volumes (The Challenger Report)
    History of Marine Geology
• Early 1900’s – reduced interest in
  oceanography (WWI)
  – 1912- Wegner- Continental Drift, no support
    from geology or geophysics of the ocean
• Meteor Expedition (German) 1925-27
  – Study of the South Atlantic- much more detail
    and better technology
  – Echo sounder- confirmed MOR
   History of Marine Geology
• Post WWII
  – Technology used by developing oceanographic
     • Gravity data
     • Seismic data
  – Office of Naval Research- financial support
  – Mohole Project (1958-1966)
          History of Marine Geology
• Deep Sea Drilling Project- DSDP (1968-1975)
   – NSF support exclusively (1968-1973)
                                               Glomar Challenger
   – International collaboration (1973-1983)

Designed to drill deep-
sea sediments and test
theory of seafloor
spreading (age of the
crust and overlying
      History of Marine Geology
 • Ocean Drilling Program- ODP (1985-2003)
    – International consortium

Improved technology,
better lab facilities,
longer drill string (9
km), international

               JOIDES Resolution
    History of Marine Geology
• Integrated Ocean Drilling Program- IODP
  (2003- 2013 first phase)
–Successor program to
–Build on legacy of
–More international

• Multiplatform
  – Nonriser (revamped Resolution- Run by US)
  – Riser (Chikyu, run by Japan)
  – Mission Specific (Europe…, special needs
    platforms- shallow water, ice-covered)
• Scientific Objectives
  – Deep Biosphere and the Subseafloor Ocean
  – Environmental Change, Processes, and Effects
     • Global Change

  – Solid Earth Cycles and Geodynamics
     • Seismogenic zone (crustal movement)
JOIDES Resolution
                            NonRiser Dilling
                            -seawater = drilling

                            143 m x 21 m

                            61 m derrick

                            10 km drill string

      Video of coring operation
                                                 Riser Drilling
                                                 -return circ of drilling
                                                 - fluid (pressure maintenance)

                                                 210 m x 38 m

                                                 92 m derrick

                                                 10 km drill string
                                                 - will be 12 km


Sampling etc:
Riserless Drilling   Riser Drilling
Mission Specific Platforms

                   European consortium

                   A range of platforms
                   - shallow water
                   - ice covered
                   - coral reef regions
    New Science Plan- for 2013
• The Science Plan for
  the International
  Ocean Discovery
  Program 2013 – 2023

      Science Plan 2013-2023
• Climate and Ocean change: Reading the
  past, informing the future
• Biosphere Frontiers: Deep life,
  biodiversity, and environmental forcing of
• Earth Connections: Deep processes and
  their impact on earth’ surface environment
• Earth in Motion: Processes and hazards on
  human time scales
Seawater pumping through the drill bit
Drill floor
Re-entry cone descending through the moonpool
Core on deck
Sectioning and
capping core
Splitting core
Discussing and describing core
ODP Leg 198- Paleocene
    Thermal Max
Underway geophysics
Biostratigraphy Lab
Measuring physical properties of the core
Onboard paleomag
                   Luxury accommodations

Fun and exercise

Shared By: