Publication: Submarine melt as a potential trigger of the North East Greenland Ice Stream margin retreat during Marine Isotope Stage 3
Full text at PDC
Advisors (or tutors)
Copernicus Gesellschaft MBH
The Northeast Greenland Ice Stream (NEGIS) has been suffering a significant ice mass loss during the last decades. This is partly due to increasing oceanic temperatures in the subpolar North Atlantic, which enhance submarine basal melting and mass discharge. This demonstrates the high sensitivity of this region to oceanic changes. In addition, a recent study suggested that the NEGIS grounding line was 20–40 km behind its present-day location for 15 ka during Marine Isotope Stage (MIS) 3. This is in contrast with Greenland temperature records indicating cold atmospheric conditions at that time, expected to favour ice-sheet expansion. To explain this anomalous retreat a combination of atmospheric and external forcings has been invoked. Yet, as the ocean is found to be a primary driver of the ongoing retreat of the NEGIS glaciers, the effect of past oceanic changes in their paleo evolution cannot be ruled out and should be explored in detail. Here we investigate the sensitivity of the NEGIS to the oceanic forcing during the last glacial period using a three-dimensional hybrid ice-sheet–shelf model. We find that a sufficiently high oceanic forcing could account for a NEGIS ice-margin retreat of several tens of kilometres, potentially explaining the recently proposed NEGIS groundingline retreat during Marine Isotope Stage 3.
© Author(s) 2019. The model simulations were performed in the HPC of Climate Change of the International Campus of Excellence of Moncloa (EOLO), supported by MECD and MICINN. We are grateful to two anonymous referees, Kerim Nisancioglu and the handling editor Andreas Vieli for their valuable help in improving this work. Also, we are thankful to Catherine Ritz for providing the original GRISLI model. This research has been supported by the Spanish Ministry of Science and Innovation (grant nos. MOCCA (CGL2014-59384-R), RIMA (CGL2017-85975-R)). Ilaria Tabone was funded by the Spanish National Programme for the Promotion of Talent and Its Employability (grant no. BES-2015-074097). Alexander Robinson was funded by the Ramón y Cajal Programme of the Spanish Ministry for Science, Innovation and Universities (grant no. RYC-2016-20587).