Occurrence and effects of open water in McMurdo Sound, Antarctica, during winter and early spring

Abstract

McMurdo Sound is well known as an area comparatively free from fast ice during the middle and late summer. Although closed to its discoverer in February 1841 by contrary winds, pack ice and new ice (Ross, 1847), the sound provided easy access to high latitudes in January and February on at least ten occasions between 1902 and 1916. Since 1955, icebreakers have assisted shipping movements in November and December, and possibly helped in dispersing the winter fast ice by cutting wide channels from Cape Bird southward. However, northerly swells and south-easterly gales are sufficient in most years to disperse fast ice from the southern end of the sound by mid or late February (Heine, 1963).