Aufeis

Auf-ice called stratified deposits of ice caused by the freezing of successive water leakage.

Doing, the water flows over existing ice. The severe frost in escaping to the surface water freezes it. In this way, successive, thin layers of ice that can accumulate to several meters thick layers of ice. The water comes from a variety of sources, which generally lie in the permafrost zone of the earth. Very often enters the water out through crevasses from lakes and rivers. Therefore auf-ice often occurs alongside and over rivers. In addition, there may be in the range of permafrost by local heat anomalies points of constantly unfrozen ground, from which the water percolates. Many Aufeiskörper include snow. Auf-ice each year re-forms in the same locations. In general, it melts in a short Arctic summer.

At high alpine, freezing streams, it may also come to Aufeisbildung blocked by groundwater discharge. The withdrawal of groundwater is blocked by ice, which in turn disturbs the steady state. This leads to a small, incremental increase in the local water table until it can emerge on the banks of the watercourse, flowing through the already formed ice and solidifies there in freezing temperatures.

This is still valid today phenomenological descriptions and explanations come from a work of Ernest de Koven Leffingwell ( 1875-1971 ).

Extensive Aufeisfläche in a wide valley, Canadian Arctic

Aufeisfeld in Tombstone Park - Spot Setting example, Yukon, Canada

Origin of the name

The term auf-ice goes back to the Baltic German zoologist Alexander Theodor von Middendorff. She has also become established in other languages ​​. Also in Alaska and Canada is called auf-ice. Where the term " icing " is alternatively used. In Siberia, where the phenomenon was first observed and interpreted by Middendorff, we now speak of " NALED " ( наледь ).