GEO/OC 103Exploring the Deep ….Today’s Tune“Pirates of the Caribbean”
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At it’s surface the ocean is in constant motion with powerful currents that stretch for thousands of miles and towering waves. Beneath the ocean’s 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 it’s surface is ocean. From space, Earth is brilliantly blue, white in places with clouds and ice, sometimes swirling with storms. “Water World” -- T. Garrison
“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
“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 Earth’s land surface was leveled to a smooth ball, the ocean would cover it to a depth of 2686 m.
“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 Earth’s radius.
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
Historical Reviewof Oceanography • Roots traced to ocean exploration. • Describing the oceans
Historical Reviewof Oceanography • The 18th century was marked by • Improvements in navigation and mapping • Accumulation of data for charts • Temperature, currents
Historical Reviewof Oceanography (Cont.) • In the United States, Benjamin Franklin (1769-1770) published the first chart of the Gulf Stream
Historical Reviewof Oceanography (Cont.) • In Britain, James Cook (1768-1779) • Constructed charts of coastlines especially for the South Pacific • Secondary discovery the Hawaiian Islands
Historical Reviewof Oceanography (Cont.) • 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 selection Published On the Origin of the Species (1859) $1200!
The Voyage of the HMS Beagle Charles Darwin Route of the HMS Beagle
Historical Reviewof Oceanography (Cont.) • Edward Forbes: British naturalist (1815-1854) • Proposed the hypothesis that no life (azoic) existed in the oceans below 550 m
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”
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
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
Geological Oceanography(Marine Geology) Study of rocks and sediments & processes responsible for their formation.
Marine Geophysics Study of rock structure in the ocean basin, properties of rocks such as magnetism, occurrence of earthquakes.
Dec 26, 20049.0 Eq, Sumatra 275,950 killed Image courtesy of BBC
March 28, 2005 8.7 Eq, Sumatra 290 killed Image courtesy of USGS
Physical Oceanography How and why ocean currents flow, air-sea interactions such as the generation of waves by the wind.
Chemical Oceanography Composition of sea water and the processes controlling and altering its composition, including marine pollution.
Biological Oceanography(Marine Biology) Organisms that live in the oceans and their relationships to the environment.
Ocean Engineering Design and installation of oceanographic instrumentation and vehicles
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
1903 www.sio.ucsd.edu 1930 www.whoi.edu 1949 www.ldeo.columbia.edu
Woods Hole Oceanographic InstitutionWoods Hole, MA Scripps Institution of OceanographyUC-San Diego
Current and Future Oceanographic Research • greater focus on international efforts and large scale interdisciplinary expeditions • Many scientists • Many ships • “remote sensing” • “unmanned” platforms
TOPEX/Poseidon satellite launched in 1992. Seasat-A, the first oceanographic satellite, was launched in 1978.
Summary:What 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