Thermokarst lakes are strong emitters of the greenhouse gas methane. Especially in regions where permafrost and glaciers are degrading large geological methane reservoirs, which were trapped for thousands of years by these cryosphere caps, are releasing gas. The high methane flux causes open water holes on lake ice. To map and characterise these holes, using only high resolution panchromatic satellite imagery, 2 methods were tested. The analysis contains an image segmentation and an overlay analysis both performed with ArcMap. The results show that an approximate location of a potential seep can be generated from panchromatic images, if interfering parts of the image such as shadows are excluded from the analysis. These geodata can be supportive for field work.