People are still building there now! The cities are only 50 years old though people were living there earlier than that when they were towns rather than cities.
People aren't very good at long term things and statistical risk. Hence smoking and debt are so popular.
Taupo looks beautiful. It is seriously glorious. But I can imagine 10km x 10km of it heading for the sky in a monstrous phreatomagmatic column of exploding gasifying pumice-forming magma.
It's not like your average pahoehoe or basaltic or scoriaceous eruptions which are nice fire-fountains to be enjoyed from a safe distance and which give plenty of earthquake warning as they gradually move magma up from down deep.
In a Taupo eruption, one day, one minute, as in a geyser, some of the liquid phase reaches boiling point and turns to gas. That pushes some stuff above out of the way. That reduction in load pushing down allows more liquid to turn to gas, which starts coming out, which reduces the load further and in minutes rather than hours or days, the whole column of liquid turns to gas and heads towards the sky.
As the gases come out, they burn in air [the organic parts] and there is a huge explosion as well as the eruption, which propels things further up and out.
It's all propelled by organic material subducted as the oceanic crust dives down under New Zealand, taking umpty mega trillions of dead marine organic material with it, like filling a monstrous fuel tank for a couple of thousand years.
I calculate, from past eruption dates, that there's about a one in ten chance of eruption happening in any lifetime. So it's not likely to happen in somebody's lifetime, but somebody will draw the short straw. It's not if it will erupt, it's when.
Odds of 1:10 aren't odds I like [when they involve serious consequences for me].
My guess is that people think there will be a warning and they'll be able to escape. There won't be and they won't. Normal volcanoes, which are visible from Taupo, rumble and shake for a while. So people can usually vacate. The volcanoes they watch [shield volcanoes Ruapehu, Ngaurahoe geonet.org.nz ] are different. Their eruptions are tiny and harmless.
To compare sizes, look at the rim of the craters surrounding them. Ruapehu has a crater lake and a rim a few hundred metres across. Taupo has a crater lake, Lake Taupo, which itself is huge, and a rim which is about 70 kilometres across. You can view them here - click to zoom in for a closer look: zenbu.net.nz
I guess there will be something like 100,000 killed when Taupo erupts. There will be large economic harm to NZ too as the electricity supplies to Auckland are destroyed and huge forestry and farming areas are destroyed. If there's a flowing foaming larva flow or a flood from Taupo pouring down the Waikato river, then Hamilton might be wiped out too and Waikato farming ruined.
The NZ$ will go down!
Mqurice |
