Chapter 4

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Bulletin of the British Volcanology Society

July 2014

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The Discovery of the Vindahellir Lava Tube

Dr Debbie Austin

In October 2013 members of the British Volcanology Society joined the Icelandic Geological Project on an expedition to monitor volcanic activity on the Grímsvötn ice cap. During the expedition, a previously unknown lava tube was discovered in the Hrafndalur Valley. The cave was explored for several hundred metres, and has since been named Vindahellir.

At the furthest explored point in Vindahellir, an abnormally large piece of volcanic glass was found embedded in the passage wall. Expedition members were unable to identify the crystal and, since exploration of Vindahellir took place at the tail end of the expedition, there was no time to conduct further investigations.

The team returned to Vindahellir in June this year. The lava tube was explored beyond the 2013 limit, where it enlarged and curved to the north, away from the Grímsvötn ice cap. After a considerable distance, it emerged from the mountainside in a remote unnamed valley east of the Hrafndalur Valley. No further deposits of volcanic glass were found.

Using radioemissive dating techniques, the team established that the lava flow containing the tube originated from one of the eighteenth century eruptions of Grímsvötn. The volcanic glass itself was resistant to all available sampling instruments and could not be dated. Since its mineral composition also remains unknown, it has been given the provisional name neckerite. 

Full documentation on the expedition, including an accurate survey of the lava tube, will be made available in a future edition of the Bulletin.