What is the Andernach Geyser?

Functionality of the “Andernach Geyser”:

Unlike the well-known hot water geysers, for example in Iceland, which shoot the water out with the steam pressure of over-heated water, the driving forces of the “Andernach Geyser” are cold ground water and carbon dioxide.

The source of the CO2 is the volcanic area of the East Eifel. The cracks and crevices of the rock formations in this area mean, that the gas meets relatively cold ground water several hundred metres below the surface of the earth. The low temperature and high pressure allow very large amounts of CO2 to be dissolved in this ground water. The ground water also flows into the approximately 350m deep drilled well of the “Andernach Geyser”.

Through the continuous inflow of ground water, the column of water rises slowly up to the earth’s surface. The weight of this column of water leads to rising pressure at increased well depths. When the well is completely full, the pressure at a depth of 350 metres is around 35 bars.

Compared to normal environmental conditions there is now a much higher amount of carbon dioxide dissolved in the well water. As the CO2-saturated water rises it becomes subject to less pressure; the previously dissolved CO2 is released as gas bubbles. The rising gas bubbles expand further as they rise towards the surface. With the inflow of ground water from deep below and the expanding volume of the carbon dioxide bubbles, a corresponding volume of water is at the same time pushed out, so that at the head of the well the water begins to overflow.

As a consequence, the pressure falls and further reduces the solubility of the carbon dioxide in the water. More and more carbon dioxide bubbles rise towards the head of the well, expand and allow more ground water to flow through. The resulting domino effect speeds this process up so rapidly that the natural spectacle of the “Andernach Geyser” appears as an impressive fountain.

After the eruption the well fills again with cold ground water and the whole process repeats itself at relatively regular intervals.

The foaming over of a bottle of carbonated water after being shaken functions according to the same physical principle.

Location of the Geyser in the “Namedyer Werth” Nature Reserve:

The Namedyer Werth was declared a nature reserve with an ornithological focus in 1985. Extensive research into alternative locations for a reactivation of the Geyser showed that the special conditions required for a working cold water geyser were only to be found on the Namedyer Werth.

In order to meet up to the special sensibilities of this area, a concept was developed – in close contact with the respective conservationist and specialist associations – which takes into equal account the nature conservation concerns, as well as allowing tourist access to this natural spectacle, which is unique in this size.

Future Perspective: The Opening of the Geyser in Early Summer 2009:

With the “Andernach Geyser” on the Namedyer Werth, the city of Andernach, together with the Vulkanpark, has succeeded in reactivating a unique natural spectacle. The aim now is to exploit the ‘world’s largest cold water geyser’ touristically, in accord with the special conditions of the nature reserve area. In the early summer of 2009, the “Andernach Geyser” is to be opened as a major attraction of the Vulkanpark, together with the experience and information centre, the ‘Geysir Erlebniswelt’.

Ticket Hotline ‘Geysir Sommer’ (‘Geyser Summer’):

Due to the great amount of interest, it is already possible to view the geyser this summer and next summer. The dates of the ‘Geyser Summer’ are published in the internet at www.andernach.net. Tickets for this event can be ordered by telephone on 0 26 32/ 29 84 20 or at the tourist information office.