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Ruapehu
In addition to the usual volcanic hazards, Ruapehu's Crater Lake ejects frequent lahars.
Ruapehu network map.
The eruption of Ruapehu, June 1996.
Scientists collecting crater lake samples.
At 2797 m, Ruapehu is the highest mountain in the North Island, and the most recent of the North Island volcanoes to have erupted. Three summit craters have been active during the last 10,000 years including South Crater which contains the currently active vent. The active vent is filled by Crater Lake; water from this lake is frequently ejected on to the ice and snow during eruptions causing lahars.
Most Recent Eruption
- When: September 25 2007
- Effects: This was an explosive eruption, lasting about 7 minutes. During the eruption explosions spread ash, rocks and water across the summit area, producing lahars in two valleys including one in the Whakapapa ski field. In contrast with the previous eruptions in 1996, there was no high ash plume to produce ash fallout over a wide area.
What does GeoNet do?
- Visual observations: 2 web cameras facing the north-west and north-east flanks of Ruapehu.
- Seismic monitoring: 10 seismographs and 6 microphones to detect volcanic explosions.
- Chemical analysis: Water chemistry and airborne gas measurements.
- Ground deformation: 8 continuous GPS stations.
