Geology 155Geology 155OceanographyOceanography

Earth SystemEarth System• Oceans are part of Earth’s System—Oceans are part of Earth’s System—Hydrosphere, Lithosphere, Hydrosphere, Lithosphere, Biosphere, AtmosphereBiosphere, Atmosphere

• System-System-A set or assemblage of A set or assemblage of things connected, associated, to things connected, associated, to form a complex unity; form a complex unity;

• Earth System-composed of Earth System-composed of interacting physical, chemical, and interacting physical, chemical, and biological processes. The system biological processes. The system provides the conditions necessary provides the conditions necessary for life on the planet. for life on the planet. – Example, plants, part of Example, plants, part of

biospherebiosphere, use solar energy to , use solar energy to change carbon dioxide into change carbon dioxide into organic carbon. organic carbon.

– Less CO2 in Less CO2 in atmosphereatmosphere helps helps cool planet.cool planet.

– Winds (Winds (atmosphereatmosphere) and ocean ) and ocean currents (currents (hydrospherehydrosphere) move ) move heat from tropics to higher heat from tropics to higher latitudes, helping to warm higher latitudes, helping to warm higher latitudes.latitudes.

– Role of Role of lithospherelithosphere? ?

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Photograph of earth taken on December 7, 1972 by the crew of Apollo 17 from a distance of about 45,000 km, while traveling to the moon. This image revolutionized our concept of earth, and it is one of the most famous photographs ever taken.Image from NASA Earth Observatory.

Right: Earth, the Blue Marble floating in the void-1997. earth as seen from space based on a montage of data from three

satellites. Image from NASA Earth Observatory.

FeedbacksFeedbacks• Earth systems interact through Earth systems interact through

feedbacks.feedbacks.– Positive feedbacksPositive feedbacks speed up change in the system. speed up change in the system.

•Example-More CO2 in atmosphere leads to global Example-More CO2 in atmosphere leads to global warmingwarming

•Warming leads to melting of ice in polar region—Warming leads to melting of ice in polar region—less light reflected back increases warmingless light reflected back increases warming

– Negative feedbacks lead to stability. They reduce Negative feedbacks lead to stability. They reduce change in the system. change in the system. •The hotter earth gets the more heat is radiated The hotter earth gets the more heat is radiated

back to spaceback to space– In past, systems all natural. Now humans have In past, systems all natural. Now humans have

influence on planet, changing the operation of influence on planet, changing the operation of many systems. Because all systems are many systems. Because all systems are interconnected, a change in one systems influences interconnected, a change in one systems influences all other systems. all other systems.

Why Study Oceans- Impact Why Study Oceans- Impact Climate and Global WarmingClimate and Global Warming•Global warming, and oceans Global warming, and oceans are connected.are connected.

– Oceans influence climate Oceans influence climate including earth's surface including earth's surface temperature, by influencing: temperature, by influencing: • Amount of CO2 in the Amount of CO2 in the

atmosphere, atmosphere, • Transport of heat from Transport of heat from

tropics to polar regions, tropics to polar regions, • The operation of the The operation of the

hydrological cycle, hydrological cycle, – Changes in ocean Changes in ocean

temperatures lead to El temperatures lead to El Nino/La NinaNino/La Nina

– Most of the oxygen in the Most of the oxygen in the atmosphere comes from the atmosphere comes from the oceans. oceans.

– The oceans cause abrupt The oceans cause abrupt climate change. climate change.

– Will global warming lead to Will global warming lead to ice age?ice age?

Why Study Oceans?Why Study Oceans?• Fisheries and other resources Fisheries and other resources importantimportant. . – Roughly 25% of the protein Roughly 25% of the protein

used by people comes from used by people comes from fish. fish.

– So much overfishing, fish are So much overfishing, fish are endangered endangered

• loss of fish changes loss of fish changes marine food webs. marine food webs.

• Changing food webs affect other Changing food webs affect other life and processes in the sea. life and processes in the sea. – How many fish can be How many fish can be

caught?caught?

•from a 1920 postcard. (Census of Marine Life)from a 1920 postcard. (Census of Marine Life)

http://marinebio.org/i/fishmarket.jpg

Sea Salt - Maio Island -

Why Should We Care Study Why Should We Care Study Oceanography?Oceanography?• Petroleum and Petroleum and

mineral resourcesmineral resources

CA gov.

Underwater mineral deposit Extracting the oil

Why Should We Care About Why Should We Care About Oceanography?Oceanography?• RecreationRecreation

LA CO Fire

Why Study Oceans ?Why Study Oceans ?• Coastal ErosionCoastal Erosion

– Coastal processes influence Coastal processes influence beaches and those who live and beaches and those who live and work near the beach. work near the beach. •Ocean waves erode beaches. Ocean waves erode beaches. •Structures along beach in most Structures along beach in most

areas will be destroyed in the long areas will be destroyed in the long run. run.

•Cost of protecting structures along Cost of protecting structures along the beaches is very high. the beaches is very high.

•Why do some beaches lose so much Why do some beaches lose so much sand that houses are destroyed? sand that houses are destroyed?

Why Study Oceans? Why Study Oceans? • Coastal pollutionCoastal pollution– Coastal pollution seems to be the cause of large scale harmful Coastal pollution seems to be the cause of large scale harmful

algal blooms. algal blooms. – Coastal pollution seems to be the cause of large scale harmful Coastal pollution seems to be the cause of large scale harmful

algal blooms. algal blooms. – Pollution also seems to create dead zones in some regions. Pollution also seems to create dead zones in some regions. – What causes the dead zones off Mississippi and Oregon in the What causes the dead zones off Mississippi and Oregon in the

summer?summer?• Damaging ocean damages us.Damaging ocean damages us.

Oiled Jackass penguins, South Africa.© International Fund for Anial Welfare (IFAW).

What is Oceanography?What is Oceanography?

OceanographyOceanographySubdisciplinesSubdisciplines

• GeologicalGeological

• PhysicalPhysical

• ChemicalChemical

• BiologicalBiological

Examples of How Oceans Examples of How Oceans Impact Us?Impact Us?

• HurricanesHurricanes

• TsunamiTsunami

Hurricane Katrina--2005Hurricane Katrina--2005

Hurricane KatrinaHurricane Katrina

Hurricane Irene-Hurricane Irene-20112011

NASA

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2004 Indonesia Tsunami2004 Indonesia Tsunami

Click image above to view film footage

Indonesia TsunamiIndonesia Tsunami

Japan Tsunami-2011Japan Tsunami-2011

simmania.darkbb.com New York Times

Gaining Knowledge of the Gaining Knowledge of the OceansOceans

• Early VoyagesEarly Voyages

• Age of DiscoveryAge of Discovery

• Science for VoyagingScience for Voyaging

Early VoyagesEarly Voyages

Early Voyages Early Voyages

• Polynesia ColonizationPolynesia Colonization

• VikingsVikings

• ChineseChinese

The Age of DiscoveryThe Age of Discovery

• Prince Henry the NavigatorPrince Henry the Navigator

• Christopher ColumbusChristopher Columbus

• Ferdinand MagellanFerdinand Magellan

Voyaging for ScienceVoyaging for Science• The First Scientific ExplorationThe First Scientific Exploration

• James CookJames Cook• Charles DarwinCharles Darwin

• The Challenger ExpeditionThe Challenger Expedition

The Challenger ExpeditionThe Challenger Expedition• Major Contributions . . .Major Contributions . . .

– First pure scientific expeditionFirst pure scientific expedition– Life was possible below 549 m (1800 ft)Life was possible below 549 m (1800 ft)– Discovered 4,717 new speciesDiscovered 4,717 new species– Collected ocean water informationCollected ocean water information

• Temperature, salinity, and water densityTemperature, salinity, and water density

• Ocean current and sediment distributionOcean current and sediment distribution

2121stst Century Technology Century Technology

UnderwaterUnderwater• SonarSonar

• SubmersiblesSubmersibles

SatelliteSatellite• MODISMODIS• QuikSCATQuikSCAT

• TRMMTRMM

Ocean FactsOcean Facts• About 70% of Earth’s surface is covered by water.About 70% of Earth’s surface is covered by water.• Average depth of the Pacific Ocean = 4,638 mAverage depth of the Pacific Ocean = 4,638 m• Average depth of the Atlantic Ocean = 3,872 mAverage depth of the Atlantic Ocean = 3,872 m• Average temperature = 3.9°C (39.0°F)Average temperature = 3.9°C (39.0°F)• Age of oceans = 4 billion yearsAge of oceans = 4 billion years

Hydrologic CycleHydrologic Cycle

• Continuous cycle of how water moves through different reservoirs, or from ocean to air, onto land, to lakes and streams and groundwater back to the sky and ocean.

Hypsographic CurveHypsographic Curve

• Shows Shows distribution of distribution of elevations and elevations and depths on Earthdepths on Earth

( Know how to read graph)