Issues

Cover: Black Island, comprised of a series of trachytic lava domes and basaltic pyroclastic cones, rises 800 m in southern McMurdo Sound, Antarctica and poses a topographic obstacle to strong southerly winds. Adiabatic winds blowing up and over the island create a local ablation zone that sculpts spectacular ice pinnacles and melt pools in the McMurdo Ice Shelf in the lee of the island. During past glaciations when marine ice sheets inundated the western Ross Sea, Black Island often stood out as a nunatak where the same adiabatic wind patterns operated. This caused enhanced ablation of the ice sheet, leading to the accumulation of basal debris rich in erratic lithologies transported from the Transantarctic Mountains. See “The local Last Glacial Maximum in McMurdo Sound, Antarctica: Implications for ice-sheet behavior in the Ross Sea Embayment” by Christ and Bierman, p. 31–47.

Photo by: Andrew Christ

Cover design by: Eric Christensen