Fig. 11

(a) Temporal changes in crevasse area at the feather-shaped (black dots) and oval (white diamonds) features. The crevasses were extracted using the manual thresholding method in binarization of the SAR image. The patterns of change are compared with monthly mean air temperature (°C) recorded at Neumeyer Station. (b) Temperature data (black lines, collected at 3-hour intervals) for 1996 and 1997 at Neumeyer Station and smoothed data (red lines, 1-week moving average). The magnitude of the increase in temperature from the wintertime minimum to a local maximum within about 2 weeks is defined as ΔT.