Thursday, May 19, 2005

Volcanoes young and old

Mount Ruapehu (2797m), NZ's most active volcano

Up early today for a commuter jostle on the way into Wellington to catch my bus North. The train I was due to get from Porirua was late, but I managed to just make the bus in time - which promptly drove to Porirua to pick people up. Ah well. The trip took just under six hours, but there were plenty of stops and a lunch break. The service I was on went straight across the Central Plateau of the North Island - an almost alienesque landscape which has been alternately carved and blasted by volcanoes. We passed Mount Ruapehu, the highest and most active volcano in the country. I remember doing a case study on the 1995 eruption there when I was in college - you can clearly see the jagged summit where it ripped apart.

After another couple of hours we arrived in Taupo (pronounced Toe-po), the main town in the region and the centre of the tourist trade around the Tongariro National Park. Today Taupo is known as a trout fishing centre, but the lake it stands on (the largest in NZ) was formed by one of the greatest volcanic explosions of all time. 26,000 years ago a 'supervolcano' erupted here (much like the one brooding under Yellowstone at the moment). It blew out 800 cubic kilometres of rock - for a comparison the eruption of Mt St Helens in 1980 produced 3 cubic km. The Taupo eruption destroyed most of the North Island - even islands 800km away were buried in ash 11cm deep. Yikes. Thankfully it's now extinct, and the 600 square km lake formed in the crater...