Aldegonda

Radar profiles

Radar measurements (RES) were collected on 5 longitudinal and 18 transversal profiles of total length 40 km covering the whole glacier area excluding the steep tongue. Most measurements were made with an interval 5 s, that corresponds to a distance between measurement points of about 10 m.

On 6 profiles in southern part of the glacier, where of hyperbolic reflections from englacial channel were recorded, the measurements were made with an interval 1 s.

Bedrock and internal reflections

The records clearly show the reflections from glacier bedrock and hyperbolic reflections presumably from englacial channels.

After RES data reduction the ice thickness and bedrock maps were constructed. Maximum ice thickness of the glacier is 216 m.

Original RES record with bedrock reflections

Surface and volume changes

Airial photos of 1990 allows to build a digital elevation model (DEM) of glacier surface and surroundings.

Comparison with map of 1936 provides the information on glacier surface and ice volume changes.

Aldegondabreen	1936	1990	Change
Area, km2	8.9328	7.6243	-1.3085
Length, m	5235	4305	-930
Average thickness, m	101	73	-28
Volume, km3	0.905	0.558	-0.347

Therefore the average annual balance of Aldegondabreen in this period is -0.7 m/ yr (in water equivalent).

Svalbard link:

Svalbard UNIS

A. Glazovsky*, Yu. Macheret*, F. Navarro**, E. Vasilenko***

*Institute of Geography RAS, Moscow, ** Polythechnical University, Madrid, *** Akadempribor, Tashkent

General

Aldegondabreen is a glacier on Svalbard, nearby the Barentsburg settlement.

Radiophysical studies were conducted there in April - May 1999 using a monopulse radar VIRL-2 with central frequency 40 MHz and a new digital recording and indication system (DRIS). The equipment allows to record simultaneously the radar-tracking information and additional georeference data from GPS and odometer with an interval from 1 up to 99 s in movement or in constant position.

Aldegondabreen, Svalbard

Radio echo sounding studies