A catastrophic meltwater flood event and the formation of the Hudson Shelf Valley
Thieler, E. Robert
Schwab, William C.
Allison, Mead A.
Driscoll, Neal W.
Donnelly, Jeffrey P.
MetadataShow full item record
The Hudson Shelf Valley (HSV) is the largest physiographic feature on the U.S. mid-Atlantic continental shelf. The 150-km long valley is the submerged extension of the ancestral Hudson River Valley that connects to the Hudson Canyon. Unlike other incised valleys on the mid-Atlantic shelf, it has not been infilled with sediment during the Holocene. Analyses of multibeam bathymetry, acoustic backscatter intensity, and high-resolution seismic reflection profiles reveal morphologic and stratigraphic evidence for a catastrophic meltwater flood event that formed the modern HSV. The valley and its distal deposits record a discrete flood event that carved 15-m high banks, formed a 120-km2 field of 3- to 6-m high bedforms, and deposited a subaqueous delta on the outer shelf. The HSV is inferred to have been carved initially by precipitation and meltwater runoff during the advance of the Laurentide Ice Sheet, and later by the drainage of early proglacial lakes through stable spillways. A flood resulting from the failure of the terminal moraine dam at the Narrows between Staten Island and Long Island, New York, allowed glacial lakes in the Hudson and Ontario basins to drain across the continental shelf. Water level changes in the Hudson River basin associated with the catastrophic drainage of glacial lakes Iroquois, Vermont, and Albany around 11,450 14C year BP (~ 13,350 cal BP) may have precipitated dam failure at the Narrows. This 3200 km3 discharge of freshwater entered the North Atlantic proximal to the Gulf Stream and may have affected thermohaline circulation at the onset of the Intra-Allerød Cold Period. Based on bedform characteristics and fluvial morphology in the HSV, the maximum freshwater flux during the flood event is estimated to be ~ 0.46 Sv for a duration of ~ 80 days.
This paper is not subject to U.S. copyright. The definitive version was published in Palaeogeography, Palaeoclimatology, Palaeoecology 246 (2007): 120-136, doi:10.1016/j.palaeo.2006.10.030.
Showing items related by title, author, creator and subject.
Stanford, Jennifer D.; Rohling, Eelco J.; Hunter, Sally E.; Roberts, Andrew P.; Rasmussen, Sune O.; Bard, Edouard; McManus, Jerry F.; Fairbanks, Richard G. (American Geophysical Union, 2006-12-09)The temporal relationship between meltwater pulse 1a (mwp-1a) and the climate history of the last deglaciation remains a subject of debate. By combining the Greenland Ice Core Project δ 18O ice core record on the new ...
Beaird, Nicholas; Straneo, Fiamma; Jenkins, William J. (John Wiley & Sons, 2015-09-30)We present the first noble gas observations in a proglacial fjord in Greenland, providing an unprecedented view of surface and submarine melt pathways into the ocean. Using Optimum Multiparameter Analysis, noble gas ...
Niu, Yi; Castro, M. Clara; Aciego, Sarah M.; Hall, Chris M.; Stevenson, Emily I.; Arendt, Carli A.; Das, Sarah B. (John Wiley & Sons, 2015-11-06)This study represents the first comprehensive noble gas study in glacial meltwater from the Greenland Ice Sheet. It shows that most samples are in disequilibrium with surface collection conditions. A preliminary Ne and Xe ...