Sir,
The photograph in Figure 1 is of the floating glacier tongue which extends out into McMurdo Sound from the slopes of Mount Erebus on Ross Island. The lateral spurs and re-entrants are well shown. I assume that these spurs are formed when a glacier or ice stream in which the ice is flowing more rapidly at the centre than at the sides enters the sea, where, freed from restraining contact with the bottom, it moves at a uniform rate.
Perhaps one of your mathematically inclined readers would be interested to derive a stress analysis for this interesting phenomenon.
28 March 1963