What are soda pans?

Soda + pan = Soda pan?

What are soda pans?

Soda pans are shallow, usually highly alkaline inland waters whose chemical-physical properties and water levels are subject to strong fluctuations throughout the year. They even fall dry more or less regularly. This is often the case in summer and early fall. The soda pans have no significant surface inflows, as is typical of most pans in the Alps. Instead, they are mainly fed by rainwater and groundwater.

Not only the soda pans themselves, but also their surroundings represent special habitats that are rare throughout Europe. They therefore enjoy special protection as a whole.

How do soda pans work?

The soda pan soil is sealed at the bottom, where the groundwater is present and the salts are supplied to the soda pan system by capillary action. The complete drying out of the soda pans helps to maintain the system. Evaporation in summer causes the salts to migrate to the soil surface of the leachates and crystallize. However, as the groundwater level drops, the capillary action breaks down, causing the soda pans to sweeten and threaten to disappear.

Where does the salt in soda pans come from?

The origin of pans is still the subject of scientific research. The same applies to where the salt that is essential for the functioning of soda pans comes from. Several theories are being discussed. One thing is certain: as salty waters, soda pans have very little to do with seawater or classic salt lakes. This is evident from the chemical compounds found in soda pans. While chloride and sodium ions dominate in seawater (NaCl = "common salt"), these play a subordinate role in soda pans. Instead, these are characterized by a particularly high content of sodium carbonate ("soda") or sodium hydrogen carbonate ("natron"). In addition, various other salts can occur in different concentrations. These include Glauber's salt (sodium sulphate), Epsom salt (magnesium sulphate) and Common salt (sodium chloride).