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The Study of the Oceans
THE OCEAN WORLD -- Just the Facts
The ocean covers 71% of the Earth's surface.
Over 97% of the water on the Earth is in the ocean.
The average depth of the ocean is about 3,800 meters.
The Mariana Trench is 11,022 meters deep, the deepest spot in the ocean.
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
If the Earth's contours were leveled to a smooth ball, the ocean would cover it
to a depth of 2,686 meters (8,810 feet).
The world 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 meters (150
On a planetary scale, however, the ocean itself is insignificant. Its average
depth is a tiny fraction of the Earth's radius: The blue ink representing the
ocean on an 8-inch paper globe is proportionally thicker.
Oceanography is a broad science that has the understanding of the oceans
as its common goal. The field is so broad that oceanography is broken down
into several disciplines based on the nature of the investigations:
Geological Oceanography (Marine Geology) -- the study of rocks and
sediments found within the oceans, and of the processes responsible for their
Marine Geophysics -- the study of the rock structure within the ocean
basins, the properties of rocks such as their magnetism, and the occurrence and
cause of earthquakes;
Physical Oceanography -- investigates how and why ocean currents flow,
and air-sea interactions such as the generation of waves by the wind;
Chemical Oceanography -- the study of the composition of sea water and
the processes that control and alter this composition, including marine
Biological Oceanography (Marine Biology) -- concerned with the organisms
that live in the oceans, and their relationships to the environment;
Ocean Engineering -- the branch of engineering that designs equipment
and installations to be used in the oceans.
Although such categories exist, individual oceanographers tend to be broad in
their outlooks and often are not easily placed into one of these "boxes". In
addition, oceanographic research tends to be highly interdisciplinary,
involving a team of investigators that combine their expertise to better
understand the oceans.
HISTORICAL REVIEW OF OCEANOGRAPHY
- The roots of Oceanography can be traced to ocean exploration. The earliest explorers had to be able to chart their courses, a process known as piloting.
- Piloting required the early navigators to plot their courses according to the stars and landmarks.
- The 18th century was marked by
- Improvements in navigation and mappingAccumulation of data for charts
- In the United States, Benjamin Franklin (1769-1770) published the first chart of the Gulf Stream
- In Britain, James Cook (1768-1779)
- Constructed charts of coastlines especially for the South PacificSecondary discovery the Hawaiian Islands
- In the 19th century curiosity about the oceans increased and voyages for scientific purposes were initiated
- 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 selectionPublished On the Origin of the Species (1859)
- Edward Forbes: British naturalist (1815-1854)
- Proposed the hypothesis that no life (azoic) existed in the oceans below 550 m
- Matthew Fontaine Maury: U.S. naval officer
- Compiled information on winds and currentsPublished The Physical Geography of the Sea (1855)"Father of physical oceanography"
- 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
Current and Future Oceanographic Research
- Dates back to the development of major interdisciplinary expeditions e.g., the Meteor Expedition: German (1925-1927)
- Bottom topography
- Vertical profiles of salinity, temperature, oxygen
- Subsequent growth was molded by the World War II and the urgent need for information on the physical structure of the oceans
Chapter Summary - What is Oceanography?
- 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
- Greater focus on international efforts and large scale interdisciplinary expeditions
- Many scientists - Many ships
- There is also a greater reliance on remote sensing and unmanned platforms
- 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
- Future oceanographers will rely increasingly on large computers and mathematical models.
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