1. Plate Tectonic and Ocean Bathymetry

4. Effects of Volcanic eruptions on the solar incoming radiation Agung 1963 Pinatubo 1991 Chichón 1982 Pinatubo facts: Earthquakes & evacuations prior to eruption 9 hours eruption with 300 meters of mountain loss 15 and 30 million tons of sulfur dioxide gas. Tropical Storm Yunya triggers rainfall of ashes (33 cm layers) 200 – 800 deaths Ashes reaches stratosphere (34 km high)  a cooling up to 0.73 C

5. Cartoon of Volcanic Impacts on the Earth Heat Budget Robock, Reviews of Geophysics, 38, 2 / May 2000

6. Volcanic Impacts on Ocean and Climate 1.Warmer Stratosphere and Cooler earth surface if eruption reaches stratosphere 2.Stronger JET stream in the Northern Hemisphere and warmer winter on continents (non-linear effects) 3.Diurnal Cycle may be reduced in amplitude 4.Hypothesis that Volcanic eruptions may trigger El Nino ? Theoretical basis: * perturbation in the heat budget may lead to a reduction in the trade winds. * uniform cooling in the tropics results in an east-west asymmetric response in the Sea Surface Temperature leading to a reduction in the trades. Feedbacks: ENSO/Climate  change Atmospheric Circulation or Ice Loading  change Litoshperic Stresses  Eruptions!

7. The Physiography of the North Atlantic Ocean Floor http://topex.ucsd.edu continental margins deep ocean basins midoceanic ridges

8. Mid-Oceanic ridges & Hydrothermal Vents Mid-Oceanic ridges are also a source of geo-heating …

9. The Ocean Circulation is generally considered to be forced by wind stress, heat and freshwater fluxes at the sea surface. However Sources of heat to our planet: solar radiation  100 W m -2 geothermal inputs  0.05-0.2 W m -2 Tides (small)

10. Estimates of the Effects of Geothermal Heating on the mean temperature profiles in the World Ocean

11. Atlantic Ocean Indian Ocean Changes in the Vertical Circulation of the Ocean (Thermohaline Circulation)

12. Why ocean bathymetry?

13. How do we measure bathymetry? Why is ocean bathymetry important? Questions:

14. How do we measure bathymetry?

15. What does it mean to be at an altitude of 4000 m? It mean that I am 4000 m above the Mean Sea Level (MSL)

16. Model of the shape of the Earth http://www.esri.com/news/arcuser/0703/geoid1of3.html http://en.wikipedia.org/wiki/Geoid geoid: The equipotential surface of the Earth's gravity field which best fits, in a least squares sense, global mean sea level (MSL)

17. The height of the Earth surface

21. Why ocean bathymetry?

22. Ocean Circulation and Climate Heat Transport affected by topography!

23. Ocean Circulation and Climate Ocean Currents take different paths!

24. Ocean Circulation and Climate Deep ocean mixing and pathways

25. Ocean Circulation and Climate Mixing energy and dissipation of tides!

26. Ocean Circulation and Biology Seamounts ….

27. Societal impacts Tsunami

28. Societal impacts Gas and oil extraction

29. 1) Reading material on Class Website Satellite Topography and Oceanography from Space 2) Homework #2 assigned. Due next Wed. Sept. 15, 2010 Before you go …

30. Understanding Isostacy and Buoyancy Exercise