Examining the interaction between multi-year landfast sea ice and the Mertz Glacier Tongue, East Antarctica: Another factor in ice sheet stability?

• Published in: Journal of Geophysical Research
• Main Authors: Massom, Robert, Giles, A. Barry, Fricker, Helen A., Legresy, Benoit, Warner, Roland C., Hyland, Glenn, Young, Neal, Fraser, Alexander D.
• Other Authors: Australian Antarctic Division (AAD), Australian Government, Department of the Environment and Energy, Antarctic Climate and Ecosystems Cooperative Research Centre (ACE-CRC), Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2010
• Subjects: FILCHNER-RONNE ICE; MARINE ICE; GROUNDING LINES; SHELF COLLAPSE; MASS-BALANCE; ROSS SEA; ICEBERG; GREENLAND; OCEAN; ACCELERATION; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Antarctic; East Antarctica; Greenland; Mertz Glacier; Mertz Glacier Tongue; Ninnis Glacier; Ross Sea; The Antarctic; Antarc*; Antarctica; glacier; Ice Sheet; Ice Shelf; Ice Shelves; Iceberg*; Sea ice
• Online Access: https://hal.archives-ouvertes.fr/hal-00561641; https://hal.archives-ouvertes.fr/hal-00561641/document; https://hal.archives-ouvertes.fr/hal-00561641/file/Journal%20of%20Geophysical%20Research%20Oceans%20-%202010%20-%20Massom%20-%20Examining%20the%20interaction%20between%20multi%25u2010year%20landfast%20sea%20ice%20and.pdf; https://doi.org/10.1029/2009JC006083

International audience The Mertz Glacier tongue (MGT), East Antarctica, has a large area of multi-year fast sea ice (MYFI) attached to its eastern edge. We use various satellite data sets to study the extent, age, and thickness of the MYFI and how it interacts with the MGT. We estimate its age to be at least 25 years and its thickness to be 10-55 m; this is an order of magnitude thicker than the average regional sea-ice thickness and too thick to be formed through sea-ice growth alone. We speculate that the most plausible process for its growth after initial formation is marine (frazil) ice accretion. The satellite data provide two types of evidence for strong mechanical coupling between the two types of ice: The MYFI moves with the MGT, and persistent rifts that originate in the MGT continue to propagate for large distances into the MYFI. The area of MYFI decreased by 50% following the departure of two large tabular icebergs that acted as pinning points and protective barriers. Future MYFI extent will be affected by subsequent icebergs from the Ninnis Glacier and the imminent calving of the MGT. Fast ice is vulnerable to changing atmospheric and oceanic conditions, and its disappearance may have an influence on ice tongue/ice shelf stability. Understanding the influence of thick MYFI on floating ice tongues/ice shelves may be significant to understanding the processes that control their evolution and how these respond to climate change, and thus to predicting the future of the Antarctic Ice Sheet.