Thermal image of the central part of the area represented 
in Fig. 5 a/b (2. April 1976, 5.40 h, altitude 1000 m, i.e. 
not enlarged from Fig. 5) 
Same image as 6a, equidensity representation, 19 C - grey 
tones ranging from « -19 (dark) to » 4? (light)