Tide records available from Alert, N.W.T. provide a possible basis for identifying more closely the time of the massive calving of the outer part of the Ward–Hunt Ice Shelf in the winter of 1961–1962. The event was possibly a result of a combination of influences. The time interval in which this event probably occurred is given as from February 6 (± 2 days) to March 6, 1962. The former date coincides with a 9% increase above the mean of the maximum difference between high and low water in a 6 h period. On February 4 a seismic shock occurred close to the ice shelf and March 6 identifies the end of a significant downward trend in the monthly plot of lowest low-water.