Geology 155 Oceanography

Earth System System-A set or assemblage of things connected, associated, or interdependent, so as to form a complex unity; a whole composed of parts in orderly arrangement according to some scheme or plan. System-A set or assemblage of things connected, associated, or interdependent, so as to form a complex unity; a whole composed of parts in orderly arrangement according to some scheme or plan. Earth System-composed of interacting physical, chemical, and biological processes that move and change materials and energy on earth. The system provides the conditions necessary for life on the planet. Earth System-composed of interacting physical, chemical, and biological processes that move and change materials and energy on earth. The system provides the conditions necessary for life on the planet. –Example, plants, which are part of the living system, use solar energy to change carbon dioxide into organic carbon. Less carbon dioxide in the atmosphere helps cool the planet. Winds and ocean currents move heat from the tropics to higher latitudes, helping to warm the higher latitudes.

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

Goal The goal of earth system science is to obtain a scientific understanding of the entire earth system on a global scale by describing how its component parts and their interactions have evolved, how they function, and how they may be expected to continue to evolve on all time scales. The goal of earth system science is to obtain a scientific understanding of the entire earth system on a global scale by describing how its component parts and their interactions have evolved, how they function, and how they may be expected to continue to evolve on all time scales.

Why Study Oceans The CO2 problem, global warming, and the ocean and all inter-related. The CO2 problem, global warming, and the ocean and all inter-related. –The ocean strongly influences climate including earth's surface temperature, by influencing: The amount of CO2 in the atmosphere, The amount of CO2 in the atmosphere, The transport of heat from the tropics to polar regions, The transport of heat from the tropics to polar regions, The operation of the hydrological cycle, The operation of the hydrological cycle, Earth's carbon cycles. Earth's carbon cycles. –Most of the oxygen in the atmosphere comes from the oceans. –The oceans may be responsible for abrupt climate change. –Will global warming plunge the world into the next ice age?

Why Study Oceans? Helps control our climate Helps control our climate

Why Study Oceans? Fisheries and other resources of the ocean are important. Fisheries and other resources of the ocean are important. –Roughly 25% of the protein used by people comes from fish. –So much overfishing, fish are endangered The loss of fish changes the marine food webs. The loss of fish changes the 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 Study Oceans? El Niño results from in part from changes in oceans. El Niño results from in part from changes in oceans. –Oceans influence weather patterns. –A change of temperature of surface water in the western north Pacific and in the tropical Atlantic can cause drought in Texas, and flooding and mudslides in California.

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

Why Study Oceans? Recreation Recreation LA CO Fire

Why Study Oceans? Damaging ocean damages us. Damaging ocean damages us. 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? Oiled Jackass penguins, South Africa.© International Fund for Anial Welfare (IFAW).

Why Study Oceans Coastal processes influence beaches and those who live and work near the beach. 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?

What is Oceanography?

Oceanography Subdisciplines Geological Geological Physical Physical Chemical Chemical Biological Biological

How Do the Oceans Impact Us? Hurricane Katrina Hurricane Katrina Indonesia Tsunami Indonesia Tsunami

Hurricane Katrina

2004 Indonesia Tsunami Click image above to view film footage

Indonesia Tsunami

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

Early Voyages

Science for Voyaging Polynesia Colonization Polynesia Colonization Vikings Vikings Chinese Chinese The Age of Discovery The Age of Discovery

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.

Stop Here

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

Feedbacks Earth systems interact through feedbacks. Earth systems interact through feedbacks. – Positive feedbacks lead to instability. They speed up change in the system. –Negative feedbacks lead to stability. They reduce change in the system. See feedbacks. feedbacks feedbacks –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.

Science The earth is a system that life itself helps to control. Biological processes interact strongly with physical and chemical processes to create the planetary environment, Life, the carbon cycle, greenhouse gases in the atmosphere, and earth's surface temperature are all interrelated. The earth is a system that life itself helps to control. Biological processes interact strongly with physical and chemical processes to create the planetary environment, Life, the carbon cycle, greenhouse gases in the atmosphere, and earth's surface temperature are all interrelated. Global change is much more than climate change. It is happening now and it is accelerating. Human activities influence the functioning of the earth system in many ways Global change is much more than climate change. It is happening now and it is accelerating. Human activities influence the functioning of the earth system in many ways Human drives multiple, interacting effects that cascade through the earth system in complex ways. Global change is not simply cause-effect paradigm. hHuman activities interact with each other and with local- and regional-scale changes in multidimensional ways. Human drives multiple, interacting effects that cascade through the earth system in complex ways. Global change is not simply cause-effect paradigm. hHuman activities interact with each other and with local- and regional-scale changes in multidimensional ways. The earth’s dynamics are characterized by critical thresholds and abrupt changes. Human activities could inadvertently trigger changes with catastrophic consequences for the earth system. Indeed, it appears that such a change was narrowly avoided in the case of depletion of the stratospheric ozone layer. The earth’s dynamics are characterized by critical thresholds and abrupt changes. Human activities could inadvertently trigger changes with catastrophic consequences for the earth system. Indeed, it appears that such a change was narrowly avoided in the case of depletion of the stratospheric ozone layer. The earth is currently operating in a no-analogue state. I The earth is currently operating in a no-analogue state. I

Earth Systems