Observations of flexural waves on the Erebus Ice Tongue, McMurdo Sound, Antarctica, and nearby sea ice

Abstract

AbstractNew strain data relating to flexural oscillations of the Erebus Glacier Tongue (EGT), McMurdo Sound, Antarctica, are presented and are analysed in the frequency domain. The data were collected during November 1989, just 3 months prior to the most recent calving of the ice tongue which occurred in March 1990. A broad-band oscillation centred on 50 s is found in both the strain measurements collected on the EGT and those collected on the sea ice nearby. The oscillation is shown, at least in part, to be propagating with a phase velocity of approximately 65 ms−1 in a direction away from the snout towards the grounding line, rather than being wholly due to a standing-wave pattern in the EGT. A coupling model between the sea ice and the EGT is proposed and is shown to compare reasonably well with the data.