LEARNING FROM THE DEEPS

1. LEARNING FROM THE DEEPS EARTH2CLASS WORKSHOPS FOR TEACHERS at LAMONT-DOHERTY EARTH OBSERVATORY Originally Presented October 2, 2004

2. HMS Challenger circumnavigated the world from 1872 - 76 in the first major scientific study of the oceans. • http://www.wshs.fcps.k12.va.us/academic/science/bjewell/ocean/hhocean/final/chall.htm

3. HMS Challenger, like all vessels up till then, determined depth to the sea floors by dropping a weighted line. Their approximate measurements at least permitted the first general understanding of the topography of the ocean bottoms. In this way, we learned that there are great mountain ranges, deep trenches, flat abyssal plains, volcanoes, and many other features forming the hidden sea floors.

4. SONAR before, during, and after WW II • In the 1920s, a new technique—SONAR-- was developed. • Sound Navigation and Ranging provided a rapid method of looking through water to identify features in the water beneath a vessel and on the sea floor. • The next slide represents how a ship can send down a signal and detect the echo.

5. P(ic)assow

6. Heezen and Tharp's "physiographic maps" • SONAR was widely employed in WW II, and many records became available after the war. • Dr. Bruce Heezen and Marie Tharp here at Lamont developed techniques beginning in the 1950s to change these 2-D records into 3-D physiographic charts, a drawing technique developed by their Columbia professors E. Raisz and A. K. Lobeck.

7. Through publication arrangements with the National Geographic Society, these physiographic images completely changed the way in which people envision the ocean floors. By the early 1970s, almost all of the oceans were depicted in such maps.

8. New shipboard and airborne techniques for mapping the ocean floors include “side scan sonar” and high-resolution seismic profiling. The next slide provides examples of such images, which are great advances over the 2-D images from the original echo-sounders. More about these techniques will be explained by our guest scientists.

9. http://marine.usgs.gov/fact-sheets/fs172-97/mapping.html

10. Since iron-rich basalts form the oceanic crust, magnetometers can reveal the paleo-magnetic patterns that allow studies of when the sea floor formed. Magnetometers revealed that the oceanic basalts erupted at different times, in patterns that preserve a record of magnetic reversals Magnetometers provide another important technique for understanding seafloor geology

11. In the 1940s, Jacques-Yves Cousteau and colleagues in the French Navy invented SCUBA (Self-Contained Underwater Breathing Apparatus.) This allowed people to study the continental shelves in person. http://www.cousteausociety.org/people.htm

12. In the 1960s, Cousteau developed habitats in which “aquanauts” could stay underwater for weeks. His 1964 film “World Without Sun” won an Academy Award. http://www.usni.org/hrp/SEALAB%20II%20on%20deckndate.htm Shortly afterwards, the U. S. Navy carried out two successful underwater living experiments called “SEALAB.” A third attempt failed, and interest waned.

13. Piccard’s “Trieste” In 1960, the U. S. Navy and Swiss inventor Auguste Piccard completed development of the bathyscaphe “Trieste.” This “underwater balloon” took Jacques Piccard and Lt. Donald Walsh to the bottom of the Mariannas Trench. In their 20 minutes there, they proved that life can exist even in the greatest depths of the oceans.

14. Small manoeuvrable research submersibles, such as the “ALVIN” operated by Woods Hole Oceanographic Institution, provide access to deep-sea features not otherwise accessible. http://www.comptons.com/encyclopedia/CAPTIONS/18005895_P.html

15. The gravity piston corer has long been one of the basic tools used to collect samples of the sediments covering the sea bottom. “Doc” Ewing required all Lamont vessels to collect at least one core each day, a practice still followed. http://www.ldeo.columbia.edu/CORE_REPOSITORY/RHP1.htm l

16. Lamont’s Deep-Sea Sample Repository houses the greatest collection of materials retrieved from the ocean floors. • http://www.ldeo.columbia.edu/CORE_REPOSITORY/RHP1.html

17. Many important discoveries have been made using cores retrieved for the Deep-Sea Sample Repository Rusty Lotti Bond and Gerard Bond have provided valuable tours in previous E2C series, as well as an informative presentation about “How Do We Use Cores for Research”

18. To go deeper into the ocean floors, the Glomar Challenger was the developed in the 1960s as the first successful deep-sea drilling ship. http://pubs.usgs.gov/publications/text/glomar.html

19. The JOIDES Resolution carried on such exploration with the ambitious Ocean Drilling Project that ended in 2003. • http://www-odp.tamu.edu/resolutn.html LDEO houses the DSSP/ODP East Coast Core Repository. The LDEO Borehole Research Group serves as the center for such drilling research here.

20. IODP Ocean drilling has now begun a new phase with the Integrated Ocean Drilling Project. This international project involves the LDEO Borehole Research Group, Texas A & M, Japan, and many other countries. IODP expands the focus to studies of • The deep biosphere and the subseafloor ocean; • Environmental change, processes and effects; and • Solid earth cycles and geodynamics.

21. Chikyu is now undergoing sea trials http://www.jamstec.go.jp/jamstec-e/odinfo/sdsreport.html

22. http://www.jamstec.go.jp/jamstec-e/odinfo/iodp_top.html

23. Using the ODP Cores Gar Esmay, East Coast Repository Superintendent, has provided some guidelines to help teachers develop curriculum materials utilizing data and information developed from DSDP and ODP cores. He suggests starting with the Citation database http://www-odp.tamu.edu/publications/cite/ and to look specifically at what’s available for Sites 552 and 659. In our visit, he will explain why these are of special interest.

24. Another valuable resource for teachers is the American Meteorological Society’s DataStreme Ocean program. This course investigates the ocean which interacts continuously with the atmosphere, geosphere, cryosphere, and biosphere by exchanging, storing and transporting matter and energy.

25. Through the DStreme Ocean web site, teachers and students can access interesting resources dealing with the Earth System, physical and chemical oceanography, biological oceanography, atmosphere/ocean interactions, the Great Lakes, and, of interest to us here, geological oceanography. Two examples of images from such links follow.

27. http://www.ngdc.noaa.gov/mgg/image/2minrelief.html It is now possible to view color relief images of the sea floor that have been created using powerful computer algorithms.

28. Weeks 2 and 4 of the American Meteorological Society’s DataStreme Ocean course focus on the marine floors. Investigation 4A explores some aspects of sediment thickness and the relationships among sediment distribution patterns, sediment thickness, and age of the oceanic crust. Investigation 4B examines terrestrial sediments deposited on the continental shelves.

29. With this background, we are ready for our visits to the LDEO Deep-Sea Sample Repository and the DSDP/ODP/IODP East Coast Repository. • During the curriculum development session this afternoon, we will try to utilize some of the available resources to create classroom-ready lesson plans.