Sinkhole

Erdfall Maujahn Moor , in the background, the upper edge of the Erdfalltrichters

A sinkhole is a depression on the surface of the earth that is created by the collapse or break-in of non-water-soluble surface layers over a natural cavity in the subsoil. The cause of the cave formation is subrosion , the dissolution of relatively easily soluble rocks (rock salt, gypsum, limestone) in the subsoil. It is therefore a karst phenomenon .

The resulting by a sinkhole subsidence is in geotechnical parlance as Erdfalltrichter or -absturz referred geomorphologically as Erdfalldoline. The latter must be differentiated from the solution doline , which is typical of limestone karst and is created by dissolution processes on the surface. Furthermore, sinkholes have to be differentiated from diurnal breaks or pinging , in which the invading cavity did not arise naturally but was caused by mining .

distribution

This article or paragraph presents the situation in Germany . Help us to describe the situation in other countries.

Small sinkhole near Saurach , only a few meters deep , created by the dissolution of gypsum in the subsoil

Sinkhole with bog formation in Vlotho- Valdorf

Sinkfalls are common in the Zechstein area on the southern edge of the Harz Mountains . In northern Germany, sinkholes formed over salt domes that had previously been hollowed out by groundwater leaching ( subrosion ) and collapsed. Lakes or bogs often developed in them. Examples are:

• Great Holy Sea and sinkhole lake near Hopsten
• Arendsee near Salzwedel
• Maujahn near Dannenberg
• Bullenkuhle near Uelzen
• Wiedensee near Herzberg am Harz
• Rudower See (above the Gorleben -Rambow salt dome)
• Sager Meer in the district of Oldenburg
• Seeburg lake in Eichsfeld
• Bernshauser Kutte in South Thuringia
• Burgsee in Bad Salzungen in South Thuringia
• Zwischenahner Meer
• District Nordhausen : Erdfallseen at Liebenrode (range: 51 ° 32 '15.0 "  N , 010 ° 38' 40.0"  O ), numerous sinkholes in Krimderode , Rüdigsdorf , of salt and most of salt digging
• Probst Jesarer lake in Lübtheen

A natural sinkhole in Brandenburg is located southeast of the Sperenberger Gipsbrüche nature reserve .

The Träbeser Loch near Träbes and Stepfershausen , town of Meiningen in the district of Schmalkalden-Meiningen (location: 50 ° 34 ′ 55.4 ″  N , 010 ° 17 ′ 38.2 ″  E ) is approx. 27 m deep and 80 m wide and exists at least since 1700.

In the area of ​​the Valdorfer Mulde near Vlotho , sinkholes with moor formation were the reason for the establishment of spa and bathing facilities in this region in the 19th century. In 1970 there was a significant sinkhole in this area.

Current sinkholes

In June 2010, a sinkhole occurred in Quickborn in Schleswig-Holstein (Pinneberg district). A salt dome around Hamburg is suspected to be the cause .

On November 1, 2010, a 20 m deep sinkhole occurred in a residential area in Schmalkalden, Thuringia , in which around 20,000 m³ of soil slid into the depths. The residents were alerted by a noise. The road was interrupted by the hole, underground cables sagged, and gas, water and electricity supplies were shut off to be on the safe side. 9 houses (25 residents) were evacuated.

Buildings destroyed by sinkholes in Nordhausen

On February 19, 2016 in Nordhausen am Harz on the former disaster control site (location: 51 ° 30 ′ 30.1 ″  N , 010 ° 46 ′ 07.8 ″  E ) a 400 m² large and 40 m deep sinkhole occurred . Shortly before, the site had been released for the new user, the district's service company for road maintenance. Firefighters who were practicing in the immediate vicinity were made aware of the sliding process by noise. People were not harmed. After a gritter could be towed away and a restricted zone had been set up, shortly after 7 p.m. the corner of a two-story building fell into the sinkhole. Above the water level in the hole, there was dust in the air from the ongoing landslides. There had already been a small sinkhole on the site in March 2010, but neither water nor cavities were found.

literature

• Karl-Heinz Büchner: The endangerment of buildings by sinkholes in the foreland of the western Harz in: Geologisches Jahrbuch C 59, Hannover, 1991

Web links

Commons : Sinkholes  - collection of images, videos and audio files

Individual evidence

1. ↑ Harald Zepp: Geomorphology: an introduction . 6th, updated edition Schöningh, Paderborn 2014, ISBN 978-3-8252-4030-1 , p. 246 .
2. ↑ Wolfgang R. Roth roof: Handbook of engineering geology and geotechnical engineering . Springer, Berlin 2002, p. 189. online here
3. ↑ Landkreis Teltow-Fläming, Office for Agriculture and Environment (Ed.): On a good reason. Booklet for the Boden-Geo-Path in the Teltow-Fläming district , 1st edition, 2008, p. 20.
4. ↑ thueringen.info
5. ↑ O. Deutloff, H. Hagelskamp, ​​G. Michel: About the sinkhole source of Bad Seebruch in Vlotho, East Westphalia. Advances in the geology of Rhineland and Westphalia 20, 27–40, Krefeld 1974
6. ↑ History workshop Exter: Hans-Peter Märgner, The sinkholes in Vlotho [1]
7. ↑ Hamburger Abendblatt : Suddenly the floor sagged
8. ↑ Hamburger Abendblatt: Salt domes under Hamburg: "Risk must be assessed". October 8, 2010. Accessed February 21, 2016, for a fee.
9. ↑ Focus : Schmalkalden: Crater had a natural cause. November 1, 2010. Retrieved February 21, 2016.
10. ↑ sinkhole on Salza Graben: First buildings collapsed. NNZ-Online.de, February 20, 2016. Retrieved on February 21, 2016. - Photo series, video of the house corner crash (5:43; crash at 04:35).
11. ↑ meinkaese: In Nordhausen the earth opens up. YouTube video, February 19, 2016, length 05:43, house corner crashed at 04:35. Retrieved February 6, 2017.
12. ↑ sinkhole on Salza Graben: building evacuated. NNZ-Online.de, February 20, 2016. Accessed February 21, 2016.
13. ↑ Area cordoned off over a large area. orf.at, February 20, 2016. Accessed February 21, 2016.