8 
NORWAY 
Jan Mayen. 
The weather conditions on Jan Mayen are extremely unfavourable for 
survey work, and the three summer months have normally only 1.1 day of 
clear weather. Oblique and vertical air photogrammetry was carried out in 
1949 and 1955. The trigonometrical survey is based on 70 main stations and 
170 other points fixed by rectangular coordinates, the heights being determined 
trigonometrically. One astronomical position as well as the azimuth are also 
fixed. Tidal observations have been undertaken and parts of the coastal con 
tour have been measured in the field. A few ground photograms were also 
taken. The greater part of the map has been plotted on a scale of 1 : 20 000, 
JAN MAYEN 
SCALE 1:50 000 
o i 
CONTOUR INTERVAL 20 M 
Fig. 1. 
The east side of Beerenberg, Jan Mayen, plotted from oblique photograms. 
Die Ostseite von Beerenberg, Jan Mayen, von Schrägaufnahmen ausgewertet. 
Flanc de l’est de Beerenberg, Jan Mayen, construit des vues obliques.