Kettle (landform)

A kettle hole is a lake whose basin is formed by the melting of dead ice blocks.

Genesis

A kettle hole is formed by the melting of dead ice and the sagging of the overlying sedimentary material. In the gradual warming up of the climate, the resulting Toteisloch is then filled by rising groundwater. Kettle holes are usually too and no outlet. However, there are lakes, which have an above-ground drainage.

The shape and size of kettle holes depends on the dimensions of the pre-existing Toteisblockes and highly variable. Small kettle holes have only a size of a few thousand to ten thousand square meters, while large kettle holes several square kilometers in size. Filled the stagnant ice a glacial trough, as well as the consequential lakes are usually stretched narrow and long. In kettle holes in tongue basins often find round shapes, but there are also lakes with rather irregular shape.

The depths of the kettle holes are also very different and vary from 0 to several dozen meters. Thus, for example, the deepest lake in Brandenburg, the 60 m deep Stechlinsee, a kettle hole. In addition, the current depth is dependent on the progressive filling of the lake basin with lake deposits, eg Mudde. In part, kettle holes, especially the smaller and flatter, already completely silted up.

Occurrence

Kettle holes are a widespread phenomenon glaciated areas young ( young moraine landscape ). They occur when there are good conditions for generating the burial of the dead ice were added. They can be found in clusters in Endmoränengebieten on Sandern ( gravel plains ) or in glacial valleys.

Kettle holes from the older Rißeiszeit respectively Saale ice age are silted up almost without exception today. But you can find based on their lake deposits preserved to this day that they, too, were once abundant.