Brenda Hall
Climate Change Institute
311 Bryand Global Sciences Center
University of Maine
Orono, ME 04469-5790
brendah at maine.edu
My primary research interests are in understanding the causes of ice ages and of rapid, millennial-scale climate changes. I also work on the stability of ice sheets. My areas of expertise include glacial geology, geomorphology, geochronology (in particular, radiocarbon and uranium-thorium dating), and paleo-lake reconstruction/geochemistry. At present, I have research projects in the Antarctic and Sub-Antarctic. One project involves reconstructing retreat of the West Antarctic Ice Sheet from its last glacial maximum position using relative sea-level curves and moraines. It is thought that an understanding of the retreat history of the ice sheet will yield clues into its future behavior. I also am working on the origin and rapid fluctuations of high-level lakes in the Dry Valleys (Antarctica). These fluctuations tell us much about the environmental and hydrologic systems in the Dry Valleys, in addition to being key pieces of evidence in the search for the origins of rapid climate change. Current work in the Sub-Antarctic is concentrating on developing a chronology for glacier fluctuations and ice-rafting changes in the South Shetland Islands. This project is aimed toward addressing the question of the interhemispheric (a)synchrony of climate change and ultimately the cause of ice ages.
GES-441 Class Page - Glacial Geology
Syllabus Fall 2004
Current Research Projects
Late Quaternary History of Reedy Glacier
Late-Glacial Chronology of Moraines in East Greenland
Glacier and Climate Variations in the South Shetland Islands (Antarctica) during and since the Last Glacial Maximum
One key problem concerns the synchrony or asynchrony of climate changes north and south of the Antarctic Convergence. It is thought that variations in Antarctic climate might lead or be out of phase with similar changes in South America. If so, a transect across the Drake Passage from Tierra del Fuego to the Antarctic Peninsula should reveal a transition from in-phase to out-of- phase climate behavior. Resolving this question of synchrony or asynchrony is critical for understanding the mechanism behind climate fluctuations.
Deglaciation of the Northern Scott Coast, Antarctica
Our objectives are to map the distribution of raised beaches along the coast. We are also interested in examining beach formation. Dates of individual beaches will be used to construct relative sea-level curves with which to constrain the timing of ice recession. Our initial results indicate that the situation along the coast is much more complex than originally thought. Some beach sediments predate the last glaciation. Young beaches may be superimposed upon old ones.
Millennial-scale fluctuations of Dry Valleys lakes
Our project is designed to develop a high-resolution paleoclimate record for the Dry Valleys of Antarctica from water-level changes of closed-basin lakes. These lakes sensitively record hydrologic variations, which are related to regional climate. Our past work has shown that, at times, the lakes were as much as 400 m deeper than they are now. Moreover, they seem to have fluctuated on a millennial timescale. Our present study centers on obtaining a continuous water-level record.
Hall, B.L., Baroni, C., and Denton, G.H., 2003. Holocene relative sea-level history of the southern Victoria Land coast, Antarctica: Global and Planetary Change, in press.
Staubwasser, M., Henderson, G.M., Berkman, P.A., and Hall, B.L., 2003. Ba, Ra, Th, and U in marine mollusc shells and the potential of 226R/Ba dating of Holocene marine carbonate shells: Geochimica et Cosmochimica Acta, in press.
Hall, B.L., and Denton, G.H., 2002. Holocene history of the Wilson Piedmont Glacier along the southern Scott Coast, Antarctica: The Holocene, v. 12, p. 619-627.
Hall, B.L., Denton, G.H., Overturf, B., and Hendy, C.H., 2002. Glacial Lake Victoria, a high-level Antarctic lake inferred from lacustrine deposits in Victoria Valley: Journal of Quaternary Science, v. 17, p. 697-706.
Hall, B.L., Denton, G.H., and Overturf, B., 2001. Glacial Lake Wright, a high-level Antarctic lake during the LGM and early Holocene: Antarctic Science, v.13, p. 53-60.
Hall, B.L., and Henderson, G.M., 2001. Use of TIMS uranium-thorium dating to determine past reservoir effects in lakes: Examples from Antarctica: Earth and Planetary Science Letters, Earth and Planetary Science Letters, v. 193, p. 565-577.
Denton, G.H., and Hall, B.L., editors, 2000. Glacial and Paleoclimatic History of the Ross Ice Drainage System of Antarctica: Geografiska Annaler, v. 82A, p. 139- 432.
Hall, B.L., 2000. Extensive lakes in the Dry Valleys (Antarctica) at the last glacial maximum: Implications for past lakes on Mars: Second International Conference on Mars Polar Science and Exploration, Reykjavik, Iceland.
Hall, B.L., and Denton, G.H., 2000. Radiocarbon chronology of Ross Sea drift, eastern Taylor Valley, Antarctica: Evidence for a grounded ice sheet in the Ross Sea at the last glacial maximum: Geografiska Annaler, v. 82A, p. 305-336.
Hall, B.L., Denton, G.H., and Hendy, C.H., 2000. Evidence from Taylor Valley for a grounded ice sheet in the Ross Sea, Antarctica: Geografiska Annaler, v. 82A, 275-303.
Conway, H., Hall, B.L., Denton, G.H., Gades, A.M., and Waddington, E.D., 1999. Past and future grounding-line retreat of the West Antarctic Ice Sheet: Science, v. 286, p. 280-283.
