Antarctic ice volume for the last 740 ka calculated with a simple ice sheet model

• Published in: Antarctic Science
• Main Author: OERLEMANS, J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2005
• Subjects: Geology; Ecology, Evolution, Behavior and Systematics; Oceanography; Antarctic; The Antarctic; Antarc*; Antarctic Science; Ice Sheet
• Online Access: http://dx.doi.org/10.1017/s0954102005002683; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102005002683

Fluctuations in the volume of the Antarctic ice sheet for the last 740 ka are calculated by forcing a simple ice sheet model with a sea-level history (from a composite deep sea δ 18 O record) and a temperature history (from the Dome C deuterium record). Antarctic ice volume reaches maximum values of about 30 × 10 15 m 3 , 3 to 8 ka after glacial maxima [defined as maximum values of the deep sea δ 18 O record]. Minimum values of ice volume reached in the course of interglacial periods are about 26 × 10 15 m 3 . Most of the time the temperature forcing (larger accumulation) and sea-level forcing (grounding-line retreat) tend to have competing effects. However, towards the end of a glacial cycle, when temperature rises and sea-level is still relatively low, the ice volume reaches a peak. The peak value is very sensitive to the relative phase of the sea-level forcing with respect to the temperature forcing. This is further studied by looking at the response of the model to purely periodic forcings with different relative phase. The large sensitivity of ice sheet size to the phase of the forcings may have some implications for dating of deep ice cores. Care has to be taken by using anchor points from the deep sea record.