ON MERTZ AND NINNIS GLACIERS, EAST ANTARCTICA

Two large glacier tongues, which extend substantially across the coast line of King George V Land in East Antarctica, have been studied by re mote sensing (synthetic aperture radar, JERS-1). The tongue of Mertz G lacier is in a state of advance, while the Ninnis Glacier tongue is re treating. Some more specific points are: The distinctive surface struc ture and the form of the glacier tongues indicates that they are float ing. While the tongue of Ninnis Glacier has lost about two-thirds of i ts area since 1913, the Mertz Glacier tongue has advanced substantiall y and has about doubled its areal extent over the same time period. Th e annual movement of the tongue of Mertz Glacier was determined as abo ut 1.2 km. This is close to the value of the advance of the tip of the tongue since 1963, which was determined as 0.9 km year(-1).