Geology 155 Oceanography

Earth System Oceans are part of Earth’s System— Hydrosphere, Lithosphere, Biosphere, Atmosphere Oceans are part of Earth’s System— Hydrosphere, Lithosphere, Biosphere, Atmosphere System-A set or assemblage of things connected, associated, to form a complex unity; System-A set or assemblage of things connected, associated, to form a complex unity; Earth System-composed of interacting physical, chemical, and biological processes. The system provides the conditions necessary for life on the planet. Earth System-composed of interacting physical, chemical, and biological processes. The system provides the conditions necessary for life on the planet. –Example, plants, part of biosphere, use solar energy to change carbon dioxide into organic carbon. –Less CO2 in atmosphere helps cool planet. –Winds (atmosphere) and ocean currents (hydrosphere) move heat from tropics to higher latitudes, helping to warm higher latitudes. –Role of lithosphere? eduweb.com

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.Earth Observatory Right: Earth, the Blue Marble floating in the void earth as seen from space based on a montage of data from three satellites. Image from NASA Earth Observatory.Earth Observatory

Feedbacks Earth systems interact through feedbacks. Earth systems interact through feedbacks. – Positive feedbacks speed up change in the system. Example-More CO2 in atmosphere leads to global warming Example-More CO2 in atmosphere leads to global warming Warming leads to melting of ice in polar region— less light reflected back increases warming Warming leads to melting of ice in polar region— less light reflected back increases warming –Negative feedbacks lead to stability. They reduce change in the system. The hotter earth gets the more heat is radiated back to space The hotter earth gets the more heat is radiated back to space –In past, systems all natural. Now humans have influence on planet, changing the operation of many systems. Because all systems are interconnected, a change in one systems influences all other systems.

Why Study Oceans- Impact Climate and Global Warming Global warming, and oceans are connected. Global warming, and oceans are connected. –Oceans influence climate including earth's surface temperature, by influencing: Amount of CO2 in the atmosphere, Amount of CO2 in the atmosphere, Transport of heat from tropics to polar regions, Transport of heat from tropics to polar regions, The operation of the hydrological cycle, The operation of the hydrological cycle, –Changes in ocean temperatures lead to El Nino/La Nina –Most of the oxygen in the atmosphere comes from the oceans. –The oceans cause abrupt climate change. –Will global warming lead to ice age?

Why Study Oceans? Fisheries and other resources important. Fisheries and other resources important. –Roughly 25% of the protein used by people comes from fish. –So much overfishing, fish are endangered loss of fish changes marine food webs. loss of fish changes marine food webs. Changing food webs affect other life and processes in the sea. Changing food webs affect other life and processes in the sea. –How many fish can be caught? from a 1920 postcard. (Census of Marine Life) from a 1920 postcard. (Census of Marine Life) Sea Salt - Maio Island -

Why Should We Care Study Oceanography? Petroleum and mineral resources Petroleum and mineral resources CA gov. Underwater mineral deposit Extracting the oil

Why Should We Care About Oceanography? Recreation Recreation LA CO Fire

Why Study Oceans ? Coastal Erosion Coastal Erosion –Coastal processes influence beaches and those who live and work near the beach. Ocean waves erode beaches. Ocean waves erode beaches. Structures along beach in most areas will be destroyed in the long run. Structures along beach in most areas will be destroyed in the long run. Cost of protecting structures along the beaches is very high. Cost of protecting structures along the beaches is very high. Why do some beaches lose so much sand that houses are destroyed? Why do some beaches lose so much sand that houses are destroyed?

Why Study Oceans? Coastal pollution Coastal pollution –Coastal pollution seems to be the cause of large scale harmful algal blooms. –Pollution also seems to create dead zones in some regions. –What causes the dead zones off Mississippi and Oregon in the summer? Damaging ocean damages us. Damaging ocean damages us. Oiled Jackass penguins, South Africa.© International Fund for Anial Welfare (IFAW).

What is Oceanography?

Oceanography Subdisciplines Geological Geological Physical Physical Chemical Chemical Biological Biological

Examples of How Oceans Impact Us? Hurricanes Hurricanes Tsunami Tsunami

Hurricane Katrina--2005

Hurricane Katrina

Hurricane Irene-2011 NASA motleynews.net

2004 Indonesia Tsunami Click image above to view film footage

Indonesia Tsunami

Japan Tsunami-2011 simmania.darkbb.com New York Times

Gaining Knowledge of the Oceans Early Voyages Early Voyages Age of Discovery Age of Discovery Science for Voyaging Science for Voyaging

Early Voyages

Polynesia Colonization Polynesia Colonization Vikings Vikings Chinese Chinese

The Age of Discovery Prince Henry the Navigator Prince Henry the Navigator Christopher Columbus Christopher Columbus Ferdinand Magellan Ferdinand Magellan

Voyaging for Science The First Scientific Exploration The First Scientific Exploration James Cook James Cook Charles Darwin Charles Darwin The Challenger Expedition The Challenger Expedition

The Challenger Expedition Major Contributions... Major Contributions... –First pure scientific expedition –Life was possible below 549 m (1800 ft) –Discovered 4,717 new species –Collected ocean water information Temperature, salinity, and water density Temperature, salinity, and water density Ocean current and sediment distribution Ocean current and sediment distribution

21 st Century Technology Underwater Sonar Sonar Submersibles Submersibles Satellite MODIS MODIS QuikSCAT QuikSCAT TRMM TRMM

Ocean 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 m Average depth of the Pacific Ocean = 4,638 m Average depth of the Atlantic Ocean = 3,872 m Average 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 years Age of oceans = 4 billion years

Hydrologic 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 Curve Shows distribution of elevations and depths on Earth Shows distribution of elevations and depths on Earth ( Know how to read graph)