- Geysir Andernach
- Germany (Andernach)
The highest 'cold water' geyser is the Geysir Andernach, which typically blows water to heights of 30-60 m (98-196 ft), and is located in Andernach, Germany. Unlike naturally-occurring hot water geysers, so-called 'cold-water' geysers are formed by cold ground water dissolving large amounts of carbon dioxide (released through cracks from the Earth's upper mantle) and effectively 'charging' the water (similar to a soda bottle); this charged underground water then erupts from a drilled well. The Andernach well is 350 m (1,148 ft) deep and was re-drilled in 2001, following its closure in 1957 due to war-torn damage. The highest recorded height of the Geysir Andernach is 61.5 m (201 ft 9 in) on 19 September 2002. The average volume of water ejected per eruption is 7,800 litres (2,060.5 US gal; 1,715 UK gal), the average interval between eruptions is 90-110 minutes; one eruption lasted 7-8 minutes.