GEO/OC 103 Exploring the Deep

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GEO/OC 103Exploring the Deep .Todays
TunePirates of the Caribbean
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Registration Problems?Please see...Melinda
JensenGeosciences Departmental Office104
Wilkinson Hallmelinda.jensen_at_oregonstate.edu737-
1238
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Water World
At its surface the ocean is in constant motion
with powerful currents that stretch for thousands
of miles and towering waves. Beneath the oceans
surface lie hidden mountain ranges, vast trenches
tens of thousands of feet deep, immense hot
springs, and huge volcanoes spewing molten rock
in massive eruptions.
Earth is a unique planet, possibly one of the
few in the galaxy that has water. Nearly 71 of
its surface is ocean. From space, Earth is
brilliantly blue, white in places with clouds and
ice, sometimes swirling with storms.
-- T. Garrison
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Chapter 1
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Just the Facts

• Over 97 of the water on the Earth is in the
  ocean.
• The average depth of the ocean is about 4000
  meters.
• The Mariana Trench is 11,022 m deep, the deepest
  spot on the planet.
• 8 tons per sq. in.
• Mt. Everest is only 8667 m above sea level

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Just the Facts

• Mauna Kea on the Big Island of Hawaii, measures
  10,600 m from the ocean floor, making it the
  tallest mountain on the planet (surpassing even
  Mt. Everest).
• If the Earths land surface was leveled to a
  smooth ball, the ocean would cover it to a depth
  of 2686 m.

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Just the Facts

• The ocean contains some 5 trillion tons of salts
• If dried and spread evenly, that mass would cover
  the entire planet to a depth of 45 m.
• On a planetary scale the ocean is insignificant.
• Its average depth is a tiny fraction of the
  Earths radius.

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Why Study the Ocean?

• Major influence on weather and climate
• Source of food, energy, medical drugs
• Transportation
• Military significance
• Recreational resource
• Major influence on the health of the planet
• Culture and history

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Historical Reviewof Oceanography

• Roots traced to ocean exploration.
• Describing the oceans

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Historical Reviewof Oceanography

• The 18th century was marked by
• Improvements in navigation and mapping
• Accumulation of data for charts
• Temperature, currents

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Historical Reviewof Oceanography (Cont.)

• In the United States, Benjamin Franklin
  (1769-1770) published the first chart of the Gulf
  Stream

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Historical Reviewof Oceanography (Cont.)

• In Britain, James Cook (1768-1779)
• Constructed charts of coastlines especially for
  the South Pacific
• Secondary discovery the Hawaiian Islands

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Historical Reviewof Oceanography (Cont.)

• In the 19th century curiosity about the oceans
  increased and voyages for scientific purposes
  were initiated

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• Charles Darwin British naturalist
• Voyage of the Beagle (1831-1836), studied geology
  and biology of the South American coastline
• Developed theory of organic evolution based on
  natural selection
• Published On the Origin of the Species (1859)

1200!
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The Voyage of the HMS Beagle
Charles Darwin
Route of the HMS Beagle
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Historical Reviewof Oceanography (Cont.)

• Edward Forbes British naturalist (1815-1854)
• Proposed the hypothesis that no life (azoic)
  existed in the oceans below 550 m

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Historical Reviewof Oceanography (Cont.)

• Matthew Fontaine Maury U.S. naval officer
• Compiled information on winds and currents
• Published The Physical Geography of the Sea
  (1855)
• Father of physical oceanography

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Historical Reviewof Oceanography (Cont.)

• C. Wyville Thompson British explorer
• Directed the Challenger Expedition (1872-1876)
• First major scientific expedition
• Globe-encircling voyage
• Chemical, physical, and biological measurements
  and collections
• Disproved Edward Forbes azoic theory by
  collecting sea life from waters as deep as 9000 m

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The Challenger Expedition
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Modern Oceanography

• Major interdisciplinary expeditions e.g., the
  Meteor Expedition German (1925-1927)
• Bottom topography
• Vertical profiles of salinity, temperature,
  oxygen
• Subsequent growth, World War II, urgent need for
  information on the physical structure of the
  oceans

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What is Oceanography Today?
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Geological Oceanography(Marine Geology)

• Study of rocks and sediments processes
  responsible for their formation.

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Marine Geophysics

• Study of rock structure in the ocean basin,
  properties of rocks such as magnetism, occurrence
  of earthquakes.

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Dec 26, 20049.0 Eq, Sumatra

• 275,950 killed

Image courtesy of BBC
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March 28, 2005 8.7 Eq, Sumatra

• 290 killed

Image courtesy of USGS
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Physical Oceanography

• How and why ocean currents flow, air-sea
  interactions such as the generation of waves by
  the wind.

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Chemical Oceanography

• Composition of sea water and the processes
  controlling and altering its composition,
  including marine pollution.

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Biological Oceanography(Marine Biology)

• Organisms that live in the oceans and their
  relationships to the environment.

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Ocean Engineering

• Design and installation of oceanographic
  instrumentation and vehicles

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Modern Oceanography (Cont.)

• Today ocean research is conducted by
  investigators in specialized marine institutions,
  as well as universities, and state and federal
  agencies
• The emphasis is on interdisciplinary,
  process-oriented research and international
  cooperation

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1903 www.sio.ucsd.edu
1930 www.whoi.edu
1949 www.ldeo.columbia.edu
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Woods Hole Oceanographic InstitutionWoods Hole,
MA
Scripps Institution of OceanographyUC-San Diego
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Current and Future Oceanographic Research

• greater focus on international efforts and large
  scale interdisciplinary expeditions
• Many scientists
• Many ships
• remote sensing
• unmanned platforms

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New Technology for Probing the Sea
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(No Transcript)
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TOPEX/Poseidon satellite launched in 1992.
Seasat-A, the first oceanographic satellite, was
launched in 1978.
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SummaryWhat is Oceanography?

• Broad science focused on the oceans
• Geology/geophysics, chemistry, physics, biology,
  engineering
• Highly interdisciplinary
• Also highly collaborative
• We are still exploring (!) but
• Feeds also into ocean policy, management, and
  conservation