Is it an illusion?
This view of Sinking Pond shows the stark contrast between the dark water lines on the tree trunks and the white snow. Sinking Pond, a special karst depression, is a 394-acre National Natural Landmark site on Arnold AFB. A unique feature of the site is that it can drain almost overnight as a function of a poorly understood change in groundwater hydrology. Maximum winter water depth varies from a few inches to 15 feet in various parts of the site. The pond is normally filled with water this time of year (November through July). However, due to the extended drought conditions in the area, the pond has been dry for some time. (Photo by Mike Hodges)