In the winter, Lake Baikal is sometimes the scene of the formation of strange little structures: there are stones balanced on top of small columns of ice. Explanations of this rare and amazing phenomenon.
It is not only in Japanese gardens what one can find. Zen stones These heaps of pebbles are balanced on top of each other. Sometimes, when the weather conditions are favorable, it is already possible to notice them on the frozen surface. from Lake Baikal, in Siberia. With the difference here, this amazing construction is not the work of human hands, but rather the work of nature.
Walkers on a fine day find themselves throwing pebbles onto the lake ice, as if by some miracle, on top of a small frozen plinth, hence the term “zen stone”. By a miracle? Not entirely. Because this rare phenomenon has a physical explanation. To understand this, head to the laboratory.
Sublimation and shadow effect
Scientists They have already reproduced the observation made on Lake Baikal and thus denied the popular hypothesis that it is the foot of ice that gradually lifts the stone. Their results show that it is the surface of the ice that sinks, in response to the phenomenon of sublimation. Sublimation corresponds to a A change in the physical state of water, which we rarely get the chance to observe. Under the influence of the sun’s rays heated by it, the ice on the surface of the lake instantly evaporates without going through the liquid phase. Thus, the surface of the lake is dropping by a few millimeters every day. But why don’t pebbles placed on ice follow the same motion?
Quite simply because the stone protects the ice beneath it from the sun’s rays. Few Like fairy chimneysThus a small column of ice forms directly under the pebble, which will gradually find itself raised above the frozen surface.
An amazing but ephemeral phenomenon: sublimation of ice will rapidly weaken the pedestal, destroying this natural work of art within two or three weeks.
