Danube Sinkhole Danube Sinkhole The Danube Sinkhole ( or ) is an incipient underground stream capture in the Upper Danube Nature Park. Between Immendingen and Möhringen and also near Fridingen (Tuttlingen), the water of the Danube sinks into the riverbed in various places. The main sinkhole is next to a field named "Brühl" between Immendingen and Möhringen. The term “sinking” is more accurate than “seeping”, because, instead of just distributing into the soil, the Danube’s water flows through underground caverns to the Aachtopf, where it emerges as the river Radolfzeller Aach. The sinking Danube water disappears into a karst water system of
Ground freezing ambient temperatures fall below ground temperatures, the liquid vapor starts condensing in the radiator, reducing the pressure in the system causing the liquid in the evaporator to boil and evaporate. This process results in heat transfer from the ground to the air and keeps the ground in a permanent frozen state. Ground freezing Ground freezing is a construction technique used in circumstances where soil needs to be stabilized so it will not collapse next to excavations, or to prevent contaminants spilled into soil from being leached away. Ground freezing has been used for at least one hundred years. Pipes are