Legend:
1) On 13.7.2020 meltwater flowed out of a large glacier gate.
2) The meltwater has deposited sand and stones here, which originate from the flank south of the glacier and possibly from the glacier surface.
3) After the ice melts, rocks covered with a lot of sand and stones (glacial polish) remain. The sand is gradually transported by rain and snowmelt towards the glacial stream and from there towards the reservoir. There, the sand is deposited and gradually fills up the reservoir.
4) After a few years, the sand from 3) has been eroded by the water to such an extent that the glacial polish is clearly visible in the exposed areas.
5) At the foot of the flank to the south of the glacier, large quantities of dead ice still remain. This also several hundred meters in front of the glacier gate. This dead ice is protected by a layer of boulders. In the steep areas, the boulders lose their grip at warm temperatures and slide off. This creates unprotected ice surfaces, which accelerates the melting process.
6) The Oberar glacier extends from the Oberaarjoch (3207m) up to the area of the glacier gate. In 2020, its length was still about 4.4km.
7) The Oberaarhorn (3631m) is the highest mountain, which is adjacent to the Oberaar glacier.