BATHYMETRIC MAPPING AND SUBBOTTOM PROFILING THROUGH LAKE ICE WITH GROUND-PENETRATING RADAR

Bathymetric mapping of lakes with sonar is essentially limited to the ice-free summer months. Recent developments in ground-penetrating rada r technology have greatly increased its portability and capabilities f or imaging through fresh water. The suitability of a backpack portable ground-penetrating radar (GPR) system for bathymetric mapping of ice- covered Arctic lakes was investigated by performing grid surveys on th ree lakes with water depths up to 19 m. It was demonstrated that GPR c an now be used to quickly produce high quality bathymetric maps and su b-bottom profiles showing sediment type and lacustrine sediment thickn ess. While water depths were measured with a precision of +/- 3%, lacu strine sediment thickness measurements (up to 5 m) had an estimated pr ecision of +/- 15%.