HOBITSS: Slow-Slip Under the Sea

To relax before the beginning of the research cruise, and to relax after a rather taxing semester, I rented a car and drove up to Tongariro National Park, 5 hours north of Wellington on the North Island. I was a little wary of driving on the opposite side of the road, on the opposite side of the car, but no mishaps occurred. The part of driving that was the most difficult was signaling, because in New Zealand the signal lever and the windshield wipers are on the opposite sides as in the U.S. So every time I tried to turn, my wipers would start waving frantically. I enjoyed a nice sunset on the way up.

There is an 18 hour time difference between Denver and New Zealand, so by the time I got to National Park Village at 9 pm, it felt like 3 am, and I was pretty much destroyed. Tongariro Crossing, one of the Great Walks of New Zealand, had some snow on the pass, and the mountains were cast in clouds, so the next day I decided to go to Tama lakes, a 17 km hike that gets close to Mount Doom, or Ngauruhoe, an active composite volcano that starred in Lord of the Rings.

The lakes are in 10,000 year old explosion craters on the saddle between Ruapehu and Ngauruhoe, two of the three giant active volcanoes in the national park (the other is Tongariro). Explosion craters form when rising magma contacts the ground water, and the volcanic heat from the magma turns the water to steam, which then blasts rock and debris out, leaving a crater.

The Maori name is Te Puna a tama (the Maori are the indigenous people of New Zealand), the springs of Tama, named after a Maori chief from 600 years ago.

How does this relate to HOBITSS? The three volcanoes are arc volcanoes resulting from the subduction of the Pacific plate under the Indian-Australian plate, the very subduction zone HOBITSS is designed to study. I got some ominous pictures of Mount Doom, as well a pretty view of Ruapehu from the south side; Ruapehu hosts several ski areas that will be active in a month or two.

On the way back I got a view of the Wanganui River, another of New Zealand’s Great Walks (although you need a canoe).