Irek Sobota
Department of Cryology and Polar Research,
Institute of Geography,
Nicolas Copernicus University,
Fredry 6/8, 97-100 Toruń, POLAND, irso@geo.uni.torun.pl

Irek Sobota


Selected cartographic and remote sensing methods in the estimation of mass balance
and volume changes of the Waldemar Glacier

Based on the available cartographic materials and air photos of the Waldemar Glacier, the attempt to estimate its mass balance off the measurement period was undertaken. The proposed methods enabled the researchers to define the average values for many years. Different time limits of cartographic materials realization have excluded the determination of mass variability over the particular years. However, they have provided an excellent base for the estimation of long time terms.
On the base of the position of equilibrium line (ELA), the mass balance of the glacier was determined in the years 1996 and 1990, and in the years involving field investigations. The obtained values differed from the measured ones of 10 cm w.e. on average, A similar but smaller difference was noted between the balance measured and the balance determined on the grounds of interdependence with the AAR coefficient value. In 1966 the net mass balance amounted to -46.5 cm w.e., and in 1990 -45.6 cm w.e., and the estimated, on the grounds of correlation from the AAR, -43.3 and -42.4 cm w.e. respectively. The mass changes of the Waldemar Glacier were estimated on the grounds of the method similar to the one proposed by Finsterwalder (1954). It was proved that maximum decrease in the surface of the Waldemar Glacier occurred in the frontal zone and along the median moraine. This decrease reached from 30 to 40 m on average. A little smaller decrease of the glacier's mass was recorded in the areas of moraine and rocky rubble materials. Due to a small surface of the glacier, the spatial differentiation of these changes was not extensive. The least values of these changes were recorded in the firn part of the glacier and at the bottom of the mountain slopes (< 10 m). An average value of the glacier's surface decrease amounted to 25.5 m. It corresponds to an average annual mass balance of the glacier of -130 cm w.e.. Another method to determine the decrease involved computer analysis. The maps of the Waldemar Glacier made in the 1978 and 1995 (Lankauf 1999) were applied. As a result, an average decrease value of the glacier mass was determined at 0.068 km3, which makes 23.8 m of the glacier's surface decrease during this period. In the period 1978-1995, the average mass balance of this glacier amounted to approximately -21.4 m w.e..
Thanks to all the methods, the average annual mass balance of the Waldemar Glacier was estimated at approximately -130 cm w.e. in the period 1978-1995.

REFERENCES
FINSTERWALDER R. 1954: Photogrametry and glacier research with special reference to glacier retreat in the Eastern Apls. Journal of Glaciology. 2(15). 306-315.
LANKAUF K. R. 1999: Recesja lodowców rejonu Kaffioyry (Ziemi Oskara II-Spitsbergen) w XX wieku. M-pis pracy doktorskiej. Instytut Geografii UMK. Toruń. ss. 290.


PUBLICATIONS

Toruńska Stacja Polarna