The Wall End Born or Wallenborn (popularly the or the Brubbel ) is a cold-water geyser in the village of Wallenborn ( Vulkaneifel district ). In addition to the Andernach geyser on Namedyer Werth, which was reactivated in 2006, it is an active cold water geyser in Germany, which, in contrast to this geyser, erupts without any technical control or aids.
The Wallende Born is operated as a fountain-like geyser: the artificial chimney is located under the surface of a small pond. The water is therefore not thrown as a fountain, but in a turbulent manner. The “propellant” of the geyser is carbon dioxide. It contains traces of other gases such as hydrogen sulfide, which can be noticed by a smell of rotten eggs.
There is still disagreement as to whether the Wallende Born can be described as naturally eruptive . Periodic gas outbreaks have been documented since time immemorial, so the Wallende Born was at least a (periodic) mofette until it was drilled . However, the high surge of water from a typical spring spring only became apparent after structural measures.
The eruptive behavior of the source
The eruptions of Kaltwassergeysirs find predictable about every 35 minutes (IBE - Engl. : Interval Between Eruptions - time from the start of an eruption until the start of next eruption) instead.
An eruption is divided into two clearly distinguishable phases:
- In the first phase, which lasts only a few seconds, the water is ejected in a column of water 2 to 4 m high, depending on the groundwater level and air pressure.
- In the second phase, the source seems to “boil” for several minutes due to the continued escape of gas, the water rising so far that the area around the well shaft is also flooded. The overflowing water flows through a walled canal into the nearby stream. The second phase ends abruptly when the gas reserves are exhausted, the water level sinks rapidly and the next resting phase begins.
The severity of the eruption and the height of the water column vary from outbreak to outbreak. In the rest phases between the eruptions, the water level in the shaft changes only slightly, and the gas leakage is minimal.
The Wallende Born is seen as a result of volcanism in the Eifel, even if the eruptive form of the spring is not a direct result of geothermal energy, but the release of carbon dioxide . The volcanic gas released from magma in the earth's crust rises through crevices and fissures to the earth's surface and partially dissolves in the groundwater to form carbonic acid .
The source is a calcium-sodium-hydrogen carbonate sourling . The spring water is very cloudy due to sediments.
The structural geological prerequisite for the geyser is an impermeable layer, a “geological trap” under which gas and groundwater collect. As soon as the solution of the gas in the water has reached saturation and the pressure of the gas that continues to flow in exceeds the load of the water column above, the gas escapes with a "sobbing" sound. Associated with this is pressure relief, which enables the gas that has already been dissolved in the water to bubble out again and to "jump" as a fountain while being carried away by groundwater.
The Wallende Born has been at least a (periodic) mofette since time immemorial. In 1933 the Mofette was drilled out in order to be able to use it economically for the production of mineral water. At a depth of 38 meters, the hole erupted, throwing out water, drilling mud and carbon dioxide. The borehole was provided with a filter pipe (piped) to a depth of 30 m. It is no longer possible to determine whether the low volume of the spring, the beginning of the Second World War or the water quality prevented economic use. The pipe was attacked very quickly by the aggressive water and partially decomposed. After the Second World War, remains of the pipe still protruded from the source pool. The gas from the mofette flowed out of the pipe. This repeatedly resulted in the death of birds that sat on the pipe.
In 1975 the Mofette was captured and provided with a well shaft with a 40 cm deep gravel bed. Water and gas now rose through a pile of gravel. The well surround was repeatedly undermined by water and gas, so that it often had to be repaired. As part of one of these repairs, the Mofette was framed with basalt columns in 1983.
The municipality of Wallenborn specifies an interval time of 55 minutes for the eruptions of the Mofette in this period with a duration of the eruption of approx. 20 minutes. A jumping water column could not form at that time.
In order to hold the mofette securely in the long term and to avoid undermining the entire area, a thorough renovation was necessary. In 2001 it was re-piped and the socket that is available today was built. Through this renovation, the Mofette became a spectacular cold water geyser.
The hubbub in literature
The Ökothriller The lava from Ulrich Magin builds background information on the Brubbel into the flow of history.
- Wolfgang Spielmann: Geological forays through the Eifel . Rhein-Mosel-Verlag, Alf / Mosel 2003, ISBN 978-3-89801-013-9 .
- Inauguration of the “Wallenden Born”. Wallenborn / Eifel, June 29, 2002, accessed December 3, 2015 .
- Wallender Born on eifel.info
- Spielmann: Geological forays through the Eifel . 2003, p. 38 .
- Rudolf Mehler: The Brubbel. Max Müller, 1988, archived from the original on March 5, 2016 ; accessed on May 22, 2019 (original website no longer available).
- Wallenborn. Eifelführer, accessed on December 3, 2015 .
- H. Wolfgang Wagner et al .: Trier and the surrounding area (= collection of geological guides , volume 60). Borntraeger, 2012, ISBN 978-3-443-15094-5 .
- Ulrich Magin: The Lava. Aufbau Verlag, Berlin 2010, p. 109 ff.