Many lakes lose in a matter of hours, forming a cave called a mill, from which water drops to the bottom of the ice sheet. These holes usually remain open throughout the melting season as melt water from surface streams and rivers falls below the ice. During the course of the study, the team was able to see how the cracks moved and how they extended further 500 meters into the lake, leading to rapid drainage of the lake.
The drone asked the team to record the flow into the cracks and the path under the ice. The reconstruction of the event can show how the melt water forms new cracks and leads to the expansion of dormant cracks. Within five hours, five million cubic meters of water were drained through cracks to the bottom of the ice sheet, forming a new void.
As more surface water is transferred to the river bed, the ice flow accelerates from 2 meters per day to more than 5 meters per day. The team said the current raised the ice sheet by half a meter. Using GPS and autopilot technology, the UAV can splice hundreds of photos to reconstruct the ice sheet surface in 3D.
Source: cnbeta.com editor in charge: Li Yi, nbjs9851