Featured Science Paper
Oceanic and atmospheric forcing of early Holocene ice-shelf retreat, George VI Ice Shelf, Antarctic Peninsula
We used lake sediment records from Alexander Island to provide a detailed picture of the Holocene history of George VI Ice Shelf. Data from core analysis provided robust evidence for one period of past ice-shelf absence between ~9,600BP and 7,730BP. This early Holocene collapse immediately followed a period of maximum Holocene warmth that is recorded in some Antarctic ice cores and coincides with an influx of warmer ocean water onto the western Antarctic Peninsula continental shelf. The absence of an ice shelf during this time suggests that early Holocene ocean-atmosphere variability in the Antarctic Peninsula was greater than that measured in recent decades.
An important advance has been made in this paper, moving on from the question of “have the ice shelves collapsed before?”, to “what were the mechanisms driving the collapse?” Evidence that both atmospheric and ocean warming are responsible shows that we must be especially alert to ocean temperature changes when assessing the future stability of ice shelves.
Smith, J., Bentley, M., Hodgson, D., Roberts, S., Leng, M., Lloyd, J., Barrett, M., Bryant, C. and Sugden, D.
Quat. Sci. Rev., 26, 500-516, 2007