Prof. Wallace Smith Broecker

Wallace Smith Broecker was born November 29, 1931, in Chicago. He received his undergraduate degree in physics at Columbia College in 1953 and went on to receive his Ph.D. in geology from Columbia University in 1958. Dr. Broecker joined the Columbia faculty in 1959 and has remained there to this day (2004): since 1977 he has held the title of Newberry Professor of Earth and Environmental Sciences at Columbia’s Lamont-Doherty Earth Observatory.

Dr. Broecker and his students employed a number of new approaches to study the Earth's climate, including the use of radiocarbon and other isotopes to date marine sediments. His studies provided the first definitive evidence that variations in the Earth's orbit around the sun and the resulting changes in insolation induce the glacial/interglacial climate cycle. Broecker also proposed the concept of a global oceanic “conveyor belt” of currents that transports heat around the globe – and can trigger abrupt shifts in the Earth's climate. He further identified the importance of changes in North Atlantic deep-water formation as a leading candidate for the cause of abrupt climate swings over the last few million years.

Broecker has also played an active role in the environmental policy debate. He has been a leading voice warning of the potential danger of increased greenhouse gases in Earth's atmosphere. He has written articles for the popular press, testified before Congressional committees and briefed officials at the highest levels of government in an effort to bring scientific insights to bear on policy issues.

A prolific researcher, teacher and author, Dr. Broecker has published over 400 scientific articles and is the author or coauthor of several textbooks, including Chemical Equilibria in the Earth (1971), Chemical Oceanography (1974), Tracers in the Sea (1982), and How To Build a Habitable Planet (1985). His two most recent books, The Glacial World According to Wally and Greenhouse Puzzles, were published in 1992 and 1994, respectively.

In 1979, Broecker was elected to membership in the National Academy of Sciences. He is also a member of the American Academy of Arts and Sciences, and a Fellow of both the American and European Geophysical Unions. Among the many other honors he has received in recognition of his creative scientific studies are: both the Maurice W. Ewing and the Roger Revelle Medals of the American Geophysical Union, in 1979 and 1995, respectively; the Arthur L. Day Medal of the Geological Society of America, in 1984; the A. G. Huntsman Award of the Bedford Institute of Oceanography, in 1985; the Alexander Agassiz Medal of the National Academy of Sciences, in 1986; the V. M. Goldschmidt Medal of the Geochemical Society, in 1987; the Wollaston Medal from the Geological Society of London, in 1990; the National Medal of Science, conferred on him by President Bill Clinton in 1996; and the Tyler Prize for Environmental Achievement, in 2002.

详见:http://www.ldeo.columbia.edu/vetlesen/recipients/1987/broecker_bio.html

Prof. George H. Denton
Professor
PhD, Yale, Quaternary and glacial geology


Research Interests
George H. Denton’s primary interest is the geological history of large ice sheets and smaller mountain glaciers. A particular concern is the role of these ice sheets in Quaternary and late-Tertiary ice ages. Another interest is abrupt ocean-atmosphere reorganizations in glacial cycles. On going projects deal with the alpine glacier history of the Chilean Andes and the Southern Alps of New Zealand.

Publications:
Denton, G.H., Lowell, T.V., Heusser, C.J., Moreno, P.I., Andersen, B.G., Heusser, L.E., Schlüchter, C., and Marchant, D.R., 1999. Interhemispheric linkage of paleoclimate during the last glaciation. Geografiska Annaler 81A, 107-153.

Denton, G.H., Heusser, C.J., Lowell, T.V., Schlüchter, C., Andersen, B.G., Heusser, L.E., Moreno, P.I., and Marchant, D.R., 1999. Geomorphology, stratigraphy, and radiocarbon chronology of Llanquihue drift in the area of the southern Lake District, Seno Reloncavi, and Isla Grande de Chiloé, Chile. ÂGeografiska Annaler 81A, 167-229.

Denton, G.H., and Hughes, T.J., 2000. Reconstruction of the Ross ice drainage system, Antarctica, at the last glacial maximum. Geografiska Annaler 82A, 2/3, 143-166.

Denton, G.H., and Marchant, D.R., 2000. The geologic basis for a reconstruction of a grounded ice sheet in McMurdo Sound, Antarctica, at the last glacial maximum. Geografiska Annaler 82A, 2/3, 167-212.

Denton, G.H. and Hughes, T.J., 2002, Reconstructing the Antarctic Ice Sheet at the Last Glacial Maximum. Quaternary Science Reviews 21, 193-202.

Denton, G.H. and Sugden, D.A., 2005, Meltwater features suggesting Miocene overriding of the Transantarctic,Mountains in Victoria Land, Antarctica. Geografiska Annaler 87A, 1-19.

Denton, G.H., Alley, R.B., Comer, G., and Broecker, W.S., 2005. The role of seasonality in abrupt climate change. Quaternary Science Reviews 24, Â1159-1182.

Denton, G.H., Broecker, W.S., and Alley, R. B., 2006. The Mystery Interval 17.5 to 14.5 kyrs ago. Pages News 14, 14-16.

Schaefer, J.M., Denton, G.H., et al., 2006. Near-synchronous interhemispheric termination of the last glacial maximum in mid-latitudes. Science 312, 1510-1513.

详见:http://www.geology.um.maine.edu/HTML-ERS/People/PeopleFSGeorgeDenton.htm