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To: miraje who wrote (51363)	5/13/2014 10:00:47 PM
From: Maurice Winn	Respond to of 86355

All around Rotorua and Taupo there is continuous belching, squirting, erupting of a minor [and sometimes significant] nature. But that's small pressure release compared with the vast accumulation in the Taupo system. Perhaps White Island will just remain an active eastern outlet on the rift zone and subduction zone. The reason Matata seems a likely boom time place is that it's on the eastern edge of the volcanic zone running from White Island across to Mount Egmont. The volcanic activity is moving general eastwards over millions of years. Volcanic activity was once to the west of NZ, with impressive volcanic rock visible in the cliffs on the west coast such as the Bethell's Beach and Muriwai area. Matata area gets earthquakes quite regularly. One of the sources of earthquakes is deep down upthrust disturbing overlying material. The Rotorua volcanic area is like a young Taupo under formation. If you have a look at a Google view of the region, and imagine all the lakes around Rotorua joined up it would be much the size and shape of lake Taupo. zenbu.co.nz Lake Taupo didn't form in one dirty great eruption. It was millions of years of continual building as the cycle of subduction, refill, eruption, subduction, refill, eruption etc continued to the present state. Rotorua region is developing along the same lines. The increasing overburden to the west means magma and upward flow is easier to the east where there's less overburden. There is plenty of life still in Ruapehu and co, and presumably therefore still Taupo and certainly enough in human life-time terms, but it's fizzling out with the eastern end becoming more active. The pumice cliffs along the Matata coast show the scale of what happens. 90% of the time, the wind is westerly, so Auckland won't be getting anything if there's a big eruption. Tauranga is in trouble though. The southern part of Tauranga is on the northern flanks of the Rotorua eruption crater rim. 35 years ago I dug 7 metres down [post hole borer] beside our Matua house to see what the geology was. Towards the bottom it turned into fine pumice. I have no idea how deep that went. We were on the edge of a steep bank which was subject to landslides, so I wanted to stabilize it to keep the house at the top of the bank rather than wake up one night at the bottom. Near Pikowai [near Matata] Mqurice