Taupo, New Zealand - Magma chamber

[Astronuc]

Molten rock accumulates in a magma chamber outside the North Island’s main volcanoes
http://www.scientificamerican.com/article/zombie-volcano-slowly-grows-beneath-new-zealand/

Something for folks near Taupo to keep an eye on.
Where's Taupo? https://en.wikipedia.org/wiki/Taupo
http://www.newzealand.com/int/lake-taupo/ Nice place.

http://www.newzealand.com/int/feature/huka-falls/

A 2015 study found that much of the main Taupo Volcanic Zone was subsiding, or sinking, as is expected after magma erupts and drains from an underground chamber. But one area, to the north and west along the Bay of Plenty coast, seemed to be rising. “I just discounted it at the time, because we were so focused on looking at the more volcanic part,” says Hamling.

Later, the team took a closer look, taking in data from global-positioning stations as well as geodetic surveys dating back to the 1950s. They found that the ground had risen by 5 millimetres per year in the 1950s, but that rate had more than doubled to about 12 millimetres a year starting in the mid-2000s. It has since dropped back to the lower rate.

 

[jedishrfu]

This has got to make people nervous even if its a millenia away from erupting. I wonder if it has an effect on property values in the region. It reminds me of why I think twice about going to California to live.

What would the estimated size of such a volcano be from past NZ geologic history and how would it affect both islands? I found this article on NZ volcanic history:

http://www.teara.govt.nz/en/map/6824/volcanic-eruptions-in-new-zealand-since-1300

I remember NOVA mega-volcano documentary about Yellowstone and how its could cover much of the US in ash with devastating effects felt in Texas (where I live, yikes).

We went to NZ a couple of years ago and it was a fabulous trip. My son did the driving mostly which made it even nicer. The people were very friendly and the scenic views just breath taking. We preferred the south island more. Our trip was late Feb to early March (end of NZ summer) where kids were going back to the Fall term at school and the temps starting feeling like autumn in NY.

 

[davenn]

What would the estimated size of such a volcano be from past NZ geologic history and how would it affect both islands? I found this article on NZ volcanic history:

http://www.teara.govt.nz/en/map/6824/volcanic-eruptions-in-new-zealand-since-1300

I remember NOVA mega-volcano documentary about Yellowstone and how its could cover much of the US in ash with devastating effects felt in Texas (where I live, yikes).

The Taupo Caldera is comparable to the size of the Yellowstone caldera
from ... http://info.geonet.org.nz/display/volc/Taupo

Taupo volcano last erupted over 1,800 years ago and is today filled by New Zealand's largest lake.
Taupo volcano first began to erupt over 300,000 years ago. It is very large and has many vents, most of which are now under Lake Taupo. Geological studies of Taupo show that the volcano makes up only the northern half of the lake and a small surrounding area but there have been numerous eruptions from different sites within this large volcano. Taupo is not a large mountain because the eruptions have been so explosive that all material has been deposited far from the vent and subsequent collapse of the ground has formed a caldera (a collapsed volcano).

Most Recent Eruption
Where: north-eastern Lake Taupo

• When: about 1,800 years ago

• Effects: The Taupo eruption was the most violent eruption in the world in the last 5,000 years; it was a complex series of events. The first phases of the eruption produced a series of five pumice and ash fall deposits over a wide area of the central North Island, especially east of Taupo and beyond Napier into Hawke Bay. The eruption culminated with a large and very energetic pyroclastic flow that devastated an area of about 20,000 km2 and filled all the major river valleys of the central North Island with pumice and ash. These pumice deposits can still be seen today and many of the major rivers in the North Island carry large amounts of this pumice when in flood. Rounded pumice found on the beaches of the North Island have come from this eruption. The Taupo eruption took place from a line of vents near the eastern side of the modern lake.

That site you linked to, jedishrfu, had a final comment about the South Island volcanic activity

This map shows the volcanic vents that have erupted in New Zealand since about 1300 and were likely to have been witnessed by people, as well as the Taupo volcano, which erupted about 200 AD. Eruptions occurred only in the North Island – there have been none in the South Island.

South Island volcanic activity, primarily all located along the east coast from Dunedin in the south to Christchurch to the north, occurred some millions of years earlier when the tectonics of the South Island were very different, namely extensional. This occurred roughly between 13 and 10 million years b.p..

When I was doing geology at Otago Univ., study of the Dunedin Volcano was a subject all students went through during first the year.
We all walked over much of the region doing mapping etc. ... ohhh them were the days when I was much younger and fitter

check out the Dunedin Volcano link at the bottom of the list in the centre of the page
http://www.gns.cri.nz/Home/Learning...oes/New-Zealand-Volcanoes/Posters-Fact-sheets

that's the region I grew up in ... home

Dave