TY - JOUR
T1 - Pattern of southern Laurentide Ice Sheet margin position changes during Heinrich Stadials 2 and 1
AU - Heath, Stephanie L.
AU - Loope, Henry M.
AU - Curry, B. Brandon
AU - Lowell, Thomas V.
N1 - Funding Information:
This hypothesis is supported by paleoclimate records from the central United States. Pollen records ( Liu et al., 2013 ; Jones et al., 2017 ) from Missouri, Kentucky and Tennessee (just south of the Lake Michigan and Huron-Erie Lobes) indicate a decline in conifer pollen and increase in oak during HI (23.5–17.5 ka) ∼19 ka, indicative of warmer and wetter conditions. In order to further test this hypothesis, paleotemperature and paleoprecipitation records from near the western margin of the Laurentide Ice Sheet in Iowa and South Dakota are needed.
Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2018/12/1
Y1 - 2018/12/1
N2 - With concerns over rising global temperatures, ice sheet stability and implications for sea level rise, the responses of former ice sheets to past climate change provide useful insights into linkages between the atmosphere, cryosphere and oceans. One example is the behavior of the Laurentide Ice Sheet (LIS) during Heinrich Stadials, times of cooler sea surface temperature (SST) in the North Atlantic. Using existing cosmogenic surface exposure ages, varve chronologies, radiocarbon ages, and optically stimulated luminescence ages from the southern LIS margin, this report tests the hypothesis that the southern side of the LIS advanced during times of surface cooling of the North Atlantic. This test reconstructs the timing of local glacial maxima and the times immediately pro- and preceding them, from multiple areas and compares them to the timing of Heinrich Stadial 2 (HS2; 26.6–23.6 ka) and to the timing of Heinrich Stadial 1 (HS1; 19.3–15.3 ka). During HS2 southern sector lobes (New England region, Huron-Erie Lobe, Lake Michigan Lobe, Green Bay Lobe and the Chippewa Lobe) advanced towards their maximum position, except for the Des Moines Lobe for which there is no applicable data. During HS1 these same lobes experienced substantial retreat, but the Des Moines Lobe advanced. Thus, the southern Laurentide margin behaved differently during the two Heinrich Stadials. This pattern may be attributed to differing east-west temperature gradients across North America and associated changes in atmospheric circulation.
AB - With concerns over rising global temperatures, ice sheet stability and implications for sea level rise, the responses of former ice sheets to past climate change provide useful insights into linkages between the atmosphere, cryosphere and oceans. One example is the behavior of the Laurentide Ice Sheet (LIS) during Heinrich Stadials, times of cooler sea surface temperature (SST) in the North Atlantic. Using existing cosmogenic surface exposure ages, varve chronologies, radiocarbon ages, and optically stimulated luminescence ages from the southern LIS margin, this report tests the hypothesis that the southern side of the LIS advanced during times of surface cooling of the North Atlantic. This test reconstructs the timing of local glacial maxima and the times immediately pro- and preceding them, from multiple areas and compares them to the timing of Heinrich Stadial 2 (HS2; 26.6–23.6 ka) and to the timing of Heinrich Stadial 1 (HS1; 19.3–15.3 ka). During HS2 southern sector lobes (New England region, Huron-Erie Lobe, Lake Michigan Lobe, Green Bay Lobe and the Chippewa Lobe) advanced towards their maximum position, except for the Des Moines Lobe for which there is no applicable data. During HS1 these same lobes experienced substantial retreat, but the Des Moines Lobe advanced. Thus, the southern Laurentide margin behaved differently during the two Heinrich Stadials. This pattern may be attributed to differing east-west temperature gradients across North America and associated changes in atmospheric circulation.
KW - Heinrich Stadials
KW - Ice sheet changes
KW - Laurentide Ice Sheet
KW - North America
KW - North Atlantic
KW - SST changes
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U2 - 10.1016/j.quascirev.2018.10.019
DO - 10.1016/j.quascirev.2018.10.019
M3 - Article
AN - SCOPUS:85055575071
SN - 0277-3791
VL - 201
SP - 362
EP - 379
JO - Quaternary Science Reviews
JF - Quaternary Science Reviews
ER -