Ngauruhoe

Ngauruhoe is a young cone that has grown on the south end of the Tongariro complex.

Ngauruhoe network map.

Ngauruhoe is the largest and youngest of the Tongariro cones being only 2,500 years old. Ngauruhoe is the most continuously active of the volcanoes in New Zealand, with the Māori recording many eruptions prior to European colonisation. The first European description was an eruption in 1839. Many of the recent eruptions have produced lava flows down the side of the cone, the last having been in 1954.

Most Recent Eruption

Where: Ngauruhoe
When: 1973 to 1975
Effects: In January 1973, Ngauruhoe discharged red-hot blocks of lava, and periodic activity continued throughout the year. In 1974 and 1975 there were explosive eruptions of ash, and blocks of lava were thrown as far as 3 km away. During the last violent eruption, gases streamed from the crater for several hours, producing a churning plume of ash that towered up to 13 km above the crater. This column then collapsed and formed ash and scoria avalanches that swept down the sides of Ngauruhoe, leaving trails of rubble in their wake.

Eruption of Ngauruhoe, 1974.

What does GeoNet do?

Visual observations: 2 web cameras facing the south-west and south-east flanks of Ngauruhoe.
Seismic monitoring: 4 seismographs and a microphone to detect volcanic explosions.
Chemical analysis: Gas chemistry and airborne gas measurements.
Ground deformation: 2 continuous GPS (CGPS) stations.

Further Information

Volcanic Hazards at Tongariro (496.29Kb)