You don’t want to be anywhere near the mountains in the conditions that form rime ice, but witnessing the aftermath is mesmerising, writes Shaun Barnett
Ice has its own language: sastrugi, needles, pancakes, hoar frost and rime are among the many forms that frozen water can assume.
Rime is ice on steroids; strange formations that grow like horizontal stalagmites on any protruding surface, be it a sign, marker pole, cairn or hut. On a recent trip to Syme Hut in Egmont National Park, I was fascinated to see that ice formations had mushroomed out from the narrow wires holding down the hut.
A curious fact (one I learned only recently): rime forms into the prevailing weather, and grows like a stalagmite, one drop at a time. Rain, sleet or snow catches on the protruding object, freezes to it and then acts as a collector, gathering more and more rime and growing towards the direction of the wind.
Here are five places to marvel at the artistry of ice.
1. Syme Hut, Egmont National Park
Perched atop Fanthams Peak, Syme Hut catches the weather no matter which direction it comes from and in winter gathers fantastical ice formations – especially on the western side. Access to the hut is via a well-travelled track from Dawson Falls, which leads through goblin forest to Hooker Shelter at the bush-edge. Beyond, the poled route is steep and exposed, usually requiring mountaineering skills, but efforts are rewarded by one of the best alpine locations in the country.
2. Tahurangi, Tongariro National Park
Mt Ruapehu’s highest summit is a rocky eminence during summer, but during winter quickly becomes festooned in mushroom-like ice. The most direct access to the summit is from Turoa Ski Field, but this is steep and access from Whakapapa is usually more straightforward. Mountaineering skills are essential on either route.
3. Mt Holdsworth, Tararua Forest Park
Mt Holdsworth is one of the most accessible and popular summits in the North Island, and with the new Powell Hut (version IV) recently opened, it’s likely to attract even more people. During winter, the summit trig often gets rime covered, as do some of the signs and marker poles en route.Take an ice-axe, and crampons if it is especially cold. Snowshoes are a good alternative when the snow is soft.
4. Meuller Hut, Aoraki Mt Cook National Park
Mueller Hut is the most accessible hut in Aoraki/Mt Cook National Park, and with its superb views of Mts Sefton and Aoraki it is a highly popular destination in summer. During winter, the hut gets far fewer visitors and those that do plan to venture there need to check avalanche conditions and have appropriate mountaineering skills. In the right conditions, rime ice forms on the hut and on the summit cairn of nearby Mt Ollivier.
5. Isthmus Peak, Lake Hawea
Isthmus Peak occupies a prominent position on the narrow isthmus between lakes Wanaka and Hawea. A track to the summit begins from a car park above Lake Hawea and climbs through farmland onto the ridge crest, which has expansive views of the Otago mountains. Schist formations, as well as the fence line past which you walk on the summit ridge, catch rime ice during winter.