HR: 0800h
AN: PP31A-0900    [Abstracts]
TI: Catastrophic Drainage of Glacial Lake Iroquois Down the Hudson River Valley: A Potential Trigger for the Intra-Allerod Cold Period
AU: * Donnelly, J P
EM: jdonnelly@whoi.edu
AF: Woods Hole Oceanographic Institution, MS 22, Woods Hole, MA 02543 United States
AU: Driscoll, N
EM: ndriscoll@ucsd.edu
AF: Scripps Institute of Oceanography, 8602 La Jolla Shores Drive, La Jolla, CA 92037 United States
AU: Uchupi, E
EM: euchupi@whoi.edu
AF: Woods Hole Oceanographic Institution, MS 22, Woods Hole, MA 02543 United States
AU: Keigwin, L
EM: lkeigwin@whoi.edu
AF: Woods Hole Oceanographic Institution, MS 22, Woods Hole, MA 02543 United States
AU: Schwab, W
EM: bschwab@usgs.gov
AF: United States Geological Survey, Woods Hole Road, Woods Hole, MA 02543 United States
AU: Thieler, E
EM: rthieler@usgs.gov
AF: United States Geological Survey, Woods Hole Road, Woods Hole, MA 02543 United States
AU: Swift, S
EM: sswift@whoi.edu
AF: Woods Hole Oceanographic Institution, MS 22, Woods Hole, MA 02543 United States
AB: Meltwater discharge to the North Atlantic during deglaciation likely influenced global oceanic circulation and climate. However, directly linking meltwater discharge events with individual climate oscillations has been difficult because of challenges in determining the location, timing and amount of meltwater discharge. New evidence from the Hudson River Valley (HRV) and the Northeastern US continental margin constrain the timing of the catastrophic draining of Glacial Lake Iroquois, that breached the moraine dam at the Narrows in New York City, eroded the HRV, and deposited large sediment lobes on the exposed New York and New Jersey continental shelf, to about 13,350 years before present (BP). Including the contribution of Glacial Lake Vermont and Glacial Lake Albany, which also drained in this event, the meltwater release was likely about 3.5x1012 m3. We regard this as a minimum estimate, as additional meltwater from the west most likely contributed to Glacial Lake Iroquois at this time and further meltwater may have been provided by subglacial reservoirs. The timing of this meltwater pulse is coincident with the onset of the Intra-Allerod Cold Period (IACP) recorded in the GISP II oxygen isotopes and the grey-scale record from the Cariaco Basin. The IACP probably correlates to short-lived cold reversals in Central North America, Atlantic Canada (Killarney Oscillation), and Central Europe (Gerzensee Oscillation). Excess 14C in Cariaco Basin sediments likely indicates a slowdown in thermohaline circulation and heat transport to the North Atlantic that initiated about 13,350 years ago. Thus the meltwater discharge out the HRV may have played an important role in slowing thermohaline circulation triggering the IACP.
DE: 4267 Paleoceanography
DE: 3000 MARINE GEOLOGY AND GEOPHYSICS
DE: 3022 Marine sediments--processes and transport
DE: 1821 Floods
DE: 1600 GLOBAL CHANGE (New category)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting