No snow in Tahoe? Time for a road trip! This week, we’re off to New Zealand, my former home-for-a-few-years during my doctoral research days. New Zealand is a wild, stark, and stunningly beautiful country, offering up a multitude of recreation activites and friendly people. Just make sure you lie through your teeth about how much you love rugby and understand the intricacies of test match cricket.
In terms of natural hazards, New Zealand is also one of the most dangerous places to live on the planet. The full spectrum of natural hazards can be found there in abundance, especially the factor that makes things extremely hazardous for people – settlements in places that experience dangerous natural phenomenon such as earthquakes, floods, tsunami, and volcanic eruptions.
The capital of New Zealand – Wellington – straddles one of the largest, most potentially damaging earthquake faults in the world – the Wellington Fault. The last major earthquake there in 1855 along the nearby Wairarapa fault literally split the city in two, with up to 18 meters (~60 ft) of horizontal displacement that is thought to be the largest ever seen on the planet. Some parts of the central business district were uplifted vertically several meters, transforming those areas from muddy marsh land into prime real estate. Real estate which humans then rushed to rebuild and expand Wellington on.
New Zealand straddles the boundary between two tectonic plates – the Australian Plate and the Pacific Plate. On the South Island, the boundary between the plates is a transform boundary, with a “strike-slip” fault system connecting the two plates as they slide past one another. This boundary is called the Alpine Fault, which is thought capable of producing a Mw >8.0 earthquake if it’s entire length were to rupture at once. At the southern tip of the North Island, right under the city of Wellington, the Wellington and Wairarapa Faults mark the beginning of the transition of the plate boundary from the strike-slip Alpine Fault to a subduction zone plate boundary under the North Island.
This subduction zone boundary is what gives rise to the many active volcanic areas of the North Island, as the downgoing Pacific Plate is melted under the Australian plate. New Zealand is home to numerous volcanoes, and as a result the country displays a diverse suite of volcanic activity. From the supervolcanic-Taupo Volcanic Zone and the bubbling mud pots of Rotorua, to the snow-covered Ruapehu and Ngaruhoe volcanoes in the Tongariro Volcanic Centre, to the potentially active cinder cones of the Auckland Volcanic Field – New Zealand has the full gamut of volcanic activity.
Geologic Background and Eruptive History
Lying far off by itself in the southwestern corner of the North Island is on of New Zealand’s most beautiful volcanoes – Taranaki Volcano – which stands right in the heart of the nearly circular Egmont National Park. From the Maori “tara” meaning “mountain peak” and “ngaki” meaning “shining,” the volcano takes it’s name from its persistent snow cover. Taranaki tops out at 2,518 m in elevation, or about 8,261 feet. It is the second highest volcano on the North Island, and the largest volcanic cone when it’s volume is measured against that of the other volcanoes of the Island.
The last eruption from Taranaki was 150 years ago at the end of a period of heightened activity, when a small ash eruption occurred around 1854. Prior to that, a larger eruption spread ash and tephra across the central North Island in 1655. Larger eruptions have occurred on average about every 500 years, and smaller eruptions about every 90 years.
Active for nearly 130,000 years, Taranaki has been the major driving force in the landscape of southwestern part of New Zealand. Three different times in that period, the volcano has experienced what volcanologists call “sector collapse,” in reference to a phenomenon where entire mile-wide portions of the volcanic cone collapse all at once, sending a barrage of debris flow material pouring off the volcano and out into the ocean. It’s hard to imagine a natgural event that would be more devastating, and thus incredible to witness from a safe vantage point, than a sector collapse.
Potential future activity at Taranaki could include lava flows, pyroclastic flows, heavy ashfall, lahars and flooding if the eruptions occurred under snowpack. The volcano is very much dormant, not extinct, and thus capable of reawakening at any time.
Taranaki is easy to get to, and in fact, it has an operation ski area on it which makes it perhaps the easiest volcano to ski in the Southern Hemisphere. Flights from Reno to Wellington in June came back at only $1,100. The exchange rate is currently $0.79 USD to $1 NZD. Once you get there, get yourself a flat white and a L&P and turn up the drum ‘n bass.
People have been skiing on Taranaki since Mr. R. Tyrer made the first turns on the volcano with a pair of homemade skis in 1917. The ski area has a great synopsis of the long and storied history of skiing at their club on their website, which you can read here.
Manganui boasts a skiable area of 59 hectares, which is 145 skiable American acres. For comparison, Squaw has 4,000. There are a total of three tow lifts, two of which are potential finger-severing nutcrackers. In this case, the most dangerous activity you might encounter while climbing and skiing this volcano may not be avalanches, or rockfall, or even eruptions – it might be getting your digits chopped off by the lifts you take at the beginning of your journey.
Once you leave Manganui, you are beyond any avalanche control, so your backcountry best-practices should kick in. Make sure you are aware of your surroundings, and that you stop to assess snowpack safety. Although Taranaki is described as New Zealand’s “most climbed mountain” things are different in the winter. Count on a 4-6 hour return climb and ski descent, if weather is good and things go as planned.
If you hit the snow right and manage to get fine weather, you are in for some delicious skiing, with a few thousand vertical feet of gullies and eroded fluted chutes to ski from the summit. Be sure to report back here with pictures and GoPro footage!
Where to Check in with the Local Scientists
Taranaki might just be the “safest” volcano I’ve written about in this series of articles, so long as it remains in a state of relative quiescence. GNS Science, my former employer, is the agency responsible for monitoring the hazards presented by earthquakes and volcanoes in New Zealand. With nine seismographs and a webcam, GNS has their eyes squarely on the volcano. Be sure to check their current activity page. Unlike many of the other “exotic” volcanoes on my list, you probably don’t need to do anything other than check the GNS activity page, and let ski patrol at Managanui know what you are up to before climbing and skiing Taranaki.