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Accessibility: DIFFICULT
WHAT'S HERE?
Ketetahi Hut roof damage, photo Ben Kennedy
Volcanic ballistic blocks (i.e., volcanic projectiles) and impact craters from the 6 August 2012 Te Maari eruption. Ketetahi Hut was hit by several ballistics, leaving behind holes you can see in the roof and floor.
LEARN ABOUT IT
Rebecca Fitzgerald / UoC
Tongariro is composed of multiple eruptive vents that have been active at different times over the past 275,000 years. The most recent eruptions were from Upper Te Maari on 6 August and 21 November 2012. Both eruptions were phreatic, meaning that no new magma was erupted. The August eruption was larger, and fortunately occurred at 11:52pm on a winter's night when no one was staying in the hut. One of the main volcanic hazards produced in the August eruption were volcanic ballistics - volcanic projectiles made of the rock cleared out when the vent formed. These travelled up to 2 km at about 200m/s this is over 700 km/hr! Around 13,000 ballistics were ejected, ranging in size from 10 cm to 3 m in diameter. These damaged a section of the Tongariro Crossing and also Ketetahi Hut (~1.5 km away). Ballistics from the November 2012 eruption only travelled a few hundred metres from the vent so did not reach the Tongariro Crossing.
HAVE A LOOK!
Impact crater! Photo Ben Kennedy
Have a look around Ketetahi Hut. If you look inside, you will see a bunk room cordoned off to the left. Be sure to look through the door's window to see where the ballistic punctured through the roof, bunks and floor. If you look down on the Hut from the track, you can see the ballistic-formed hole in the roof covered in Plexiglas.
Follow the path down towards Ketetahi carpark about 20 metres and on the left you will see a fenced off impact crater. This crater is 5.5 m in diameter. Look inside and you will see the partially buried ballistic responsible. Note its size in comparison to the crater. How much smaller is it than the crater? What does this tell you about human safety if you are unlucky enough to be caught in a ballistic shower?
On the way to and from Ketetahi Hut, look out for ballistic impact craters along the sides of the track and large light coloured boulders (ballistics) at the bottom of slopes and valleys. These are especially noticeable on the Blue Lake side of the Hut.
Upper Te Maari crater is the steaming crater on your right looking towards Taupo.
Follow the path down towards Ketetahi carpark about 20 metres and on the left you will see a fenced off impact crater. This crater is 5.5 m in diameter. Look inside and you will see the partially buried ballistic responsible. Note its size in comparison to the crater. How much smaller is it than the crater? What does this tell you about human safety if you are unlucky enough to be caught in a ballistic shower?
On the way to and from Ketetahi Hut, look out for ballistic impact craters along the sides of the track and large light coloured boulders (ballistics) at the bottom of slopes and valleys. These are especially noticeable on the Blue Lake side of the Hut.
Upper Te Maari crater is the steaming crater on your right looking towards Taupo.
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Directions/Advisory
Park either at Ketetahi carpark or (if doing the Tongariro Crossing) the Mangatepopo carpark
You are within the Te Maari eruption summit hazard zone. This area was hit by ballistics in 2012.
Google Directions
Accessibility:
DIFFICULT
The fastest route to Ketetahi Hut is to walk from the Ketetahi carpark side of the Tongariro Crossing (2-3 hr walk). However, if you intend to do the full Crossing, the easier route would be to start from the Mangatepopo carpark (about a 5 hr walk to Ketetahi Hut, then an additional 1½ hours to the end of the Crossing at the Ketetahi carpark).
Features
Volcanic
Geological Age
Holocene, 6th August 2012
Zealandia Evolution Sequence
Pākihi Supergoup: 5 million years ago – present
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