The Great ACT-NSW-NZ Trip, 2023-2024 - Lake Taupō
I didn't just go to Aotearoa for the animals and plants - I wanted to see the geology as well. Australia hasn't done much apart from erode for the last 99 million years, but New Zealand is on the tectonic boundary between the Australian and Pacific plates, so the geology is much more active. In fact, in some areas it's positively lively.
This is Lake Taupō, a very large lake in the middle of the North Island, and the most active supervolcano in the world. The last big eruption, about 230 CE, blew out over 100 cubic kilometers of rock, much of it over seven or eight minutes. The previous one, 25750 years ago, blasted out over 10 times that. Large parts of the island were buried in hundreds of meters of red-hot volcanic ash, travelling at just under the speed of sound, that settled still hot enough to fuse into ignimbrite rock. The very term ignimbrite was coined in New Zealand to describe this kind of pyroclastic deposit. Microscopic diatoms from the lake sediments have been found mixed with the ash that landed in the Chatham Islands over 800km away. It's also made a nice dating layer in the Antarctic ice cap.
And if all this ash and the volcanic domes and geothermal fields around the lake weren't enough, the fact that the lake has black beaches, with a strandline of fist-sized pumice, and steep cliffs around the periphery, should be a big clue that this is not a healthy place to be. At least over geological periods. In theory there should be a little warning the next time the supervolcano decides to blow out a crater the size of Singapore.
@purrdence and I stayed at two places around the caldera - Taupo township, and a much smaller place on the southern end of the lake with a name that translates as 'Sandfly and all his mates'. Both venues had geothermal hot tubs attached. We also visited the Craters of the Moon geothermal field, and the Huka Falls cascade.
Craters of the Moon was certainly pungent - the numerous fumeroles and mudpots percolate a lot of sulphur, arsenic and other elements. One of the now-collapsed fumeroles, the Devil's Trumpet, used to be nocturnal pyrotechnic display, after guides threw kerosene-soaked sackng in and got a 50-foot column of fire in responce.
Some of the species I've seen before - most from Purrdence's visit to the area a year earlier, but also some from Australia. And at least two from my carport here in Perth.
