Holocene and pre-Holocene temporary disappearance of the George VI Ice Shelf, Antarctic Peninsula

• Published in: Antarctic Science
• Main Authors: Hjort, C., Bentley, M.J., Ingólfsson, Ó.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2001
• Subjects: Geology; Ecology, Evolution, Behavior and Systematics; Oceanography; Antarctic; Antarctic Peninsula; Alexander Island; George VI Ice Shelf; George VI Sound; Two Step Cliffs; Antarc*; Antarctic Science; Ice Shelf; Ice Shelves
• Online Access: http://dx.doi.org/10.1017/s0954102001000426; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102001000426

We present evidence for the absence of the George VI Ice Shelf during a brief period in the mid-Holocene and during one or more earlier interstadials or interglacials. Barnacle Bathylasma corolliforme shells sampled from ice shelf moraines at Two Step Cliffs on Alexander Island have been dated to c , 5750–6000 14 C yr BP( c . 6550–6850 cal yr BP) and imply seasonally open water in the George VI Sound during this period. Other shells are beyond the range of radiocarbon dating and imply open water during one or more previous interglacial or interstadial period, prior to 40 000 14 C yr BP. Our results show that the ongoing collapse of some Antarctic Peninsula ice shelves is not unprecedented.