TY - JOUR
T1 - Unstable ice stream in Greenland during the Younger Dryas cold event
AU - Rinterknecht, Vincent
AU - Jomelli, Vincent
AU - Brunstein, Daniel
AU - Favier, Vincent
AU - Masson-Delmotte, Valérie
AU - Bourlès, Didier
AU - Leanni, Laëtitia
AU - Schläppy, Romain
N1 - The research leading to these results has received funding from INTERACT (grant agreement no. 262693) under the European Community’s Seventh Framework Programme, and from Agence Nationale de la Recherche (ANR) CEPS Green Greenland project (grant ANR-10-CEPL-0008).
PY - 2014/9
Y1 - 2014/9
N2 - Past, present, and future ice sheet stability is closely linked to the dynamic behavior of major draining ice streams and surrounding ice shelves. While short observational records document the recent variability and acceleration of ice streams, the long-term dynamics of ice streams remain poorly documented. Here, we date the Pjetursson’s Moraine on Disko Island, Greenland, to 12.2 ± 0.6 ka and demonstrate that the Jakobshavn Isbræ (JI) ice stream collapsed during the middle of the Younger Dryas (YD) cold interval. We suggest that this collapse was due to the incursion of warm subsurface water under the ice shelf fronting the JI ice stream, as well as increased surface-air temperature and sea-surface temperature seasonality starting at the beginning of the YD cold interval. The triggered acceleration of the land-based JI and the delivery of icebergs into Disko Bugt potentially contributed to Heinrich Event 0 at the end of the YD. The collapse of the JI ice stream 12.2 ± 0.6 ka ago demonstrates that calving marine-based ice margins can respond rapidly to environmental changes. It provides a new benchmark for marine-terminating ice stream models.
AB - Past, present, and future ice sheet stability is closely linked to the dynamic behavior of major draining ice streams and surrounding ice shelves. While short observational records document the recent variability and acceleration of ice streams, the long-term dynamics of ice streams remain poorly documented. Here, we date the Pjetursson’s Moraine on Disko Island, Greenland, to 12.2 ± 0.6 ka and demonstrate that the Jakobshavn Isbræ (JI) ice stream collapsed during the middle of the Younger Dryas (YD) cold interval. We suggest that this collapse was due to the incursion of warm subsurface water under the ice shelf fronting the JI ice stream, as well as increased surface-air temperature and sea-surface temperature seasonality starting at the beginning of the YD cold interval. The triggered acceleration of the land-based JI and the delivery of icebergs into Disko Bugt potentially contributed to Heinrich Event 0 at the end of the YD. The collapse of the JI ice stream 12.2 ± 0.6 ka ago demonstrates that calving marine-based ice margins can respond rapidly to environmental changes. It provides a new benchmark for marine-terminating ice stream models.
U2 - 10.1130/G35929.1
DO - 10.1130/G35929.1
M3 - Article
SN - 0091-7613
VL - 42
SP - 759
EP - 762
JO - Geology
JF - Geology
IS - 9
ER -
