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).