Originally posted by aorAki
...or it could all be part of the response to the September earthquake and the subsequent February and June 'quakes.....and thousands of aftershocks
(something like 6800 since September).
I repeat (sorry if it is ad nauseum) there is no possibility of the Banks Peninsula volcanoes reactivating. While it makes a nice story and may
'appear' that something is happening regarding the volcano, it is the earthquakes and faults being activated/reactivating that is responsible, not the
volcano. Sorry, I'm firm on this.
edit on 14-6-2011 by aorAki because: ()
I took some time yesterday, over night and today to get a better understanding of what the situation in NZ is.
YES! I agree with you,
it is very unlikely that the Banks volcano's might erupt; as in NO ERUPTION. All based on any and all of the current
BUT I saw something that is far worse; still looking into it but it seems to me South Island is breaking into two or three pieces. NOT NOW - more
likely over this next few thousand years; this process already started.
TWIST = The Way I See Things
To understand this post you will need to open a geological map or at least Google Earth centred on NZ at eye alt of about 3,000 km.
New Zealand has two tectonic plate actions and NZ itself is on a transition section between the two actions. To the North East you have a very strong
subduction zone where the Pacific plate is pushing under the Australian plate. This zone stretches from about Samoa until Wellington.
To the SW you have a Sliding zone between Australian and South Pacific Plate. The rift stretch about 2,000 km and Macquarie Island is almost in the
middle. There is no subduction in the far South - yet, they are pushing and rubbing; soon one will have to give in and dive. Closer to the shore of
NZ it looks like the AU plate is diving under NZ. Age in this area is about 30 mil years where as the subduction to the NW of North island is about
65 mil years and the area of North Island itself is about 40-50 mil years.
The Australian Plate push on the North Island was a bit stronger or resistance against South Island from Pacific plate was stronger - whichever or
both caused the North Island and the South island; which was one single island some 40 mil years ago - to tear. They literally fractured like an arm
or leg bone as seen on X-ray. It is kind of like imagining the Yin-Yang sign with Kaikoura about in the center.
Now the pressure is on for South Island. The Northern portion is still strongly on the Australian plate while the Southern portion is on the Pacific
plate. Right in the middle of these - you have ChristChurch - and that is where the next stress point is. Sometime in the future the South Island is
going to tear apart and NZ will become three big islands; this I don't think will take a few million years either.
Now, the volcanic activity.
In this particular NZ area, looking to where you already have big subduction zones you will see large numbers of volcano's stretching from North
island all the way up to Samoa. These are mostly on the Australian plate around 150 to 200 km from the edge of the Australian plate.
There are two factors causing this. First the South Pacific plate is pushing under the Australian plate; so literally the SPP is diving towards the
molten core. But the Australian plate is not undamaged either. As the SPP is forcing under - it also press upwards on the rim of the Australian
plate. Resulting in fissure / cracking of the Australian plate this 150+ km from the rim.
The second factor is now the pressure on the magma - the flow is getting blocked by the Pacific plate diving resulting in a pressure build up. Since
there is a weakening on the plate above - eventually they push out to the surface - Volcano!
Because of the Australian / Antarctic plate expanding rift - I expect there is going to be a reversal around South Island where the older Australian
plate is going to dive under the South Pacific plate. Could this be true? So just Google Earth to see the potential is real: The general table
around South island is about 100 to 800 meter below sea level, even at the South side of the ridge off the shoreline Resolution Island; then as you
move over to the Australian plate - that is suddenly 3,500+ meter below sea level. Compare this to North Island for example off Portland island - the
north edge of the rift is less than 200 meters while the Pacific plate is 3,000+ meters.
Go South say West from Broughton islands - AU plate is average 4,500 and SP plate is 2,800 meters below sea level. Further South at Macquarie island
both AU and Pacific plates are about 4,000 meters deep. NOT overnight, but a few thousand years sounds reasonable.
Volcano wise, there a question of what is happening on the NW shore; I suspect the South Pacific plate (New Zealand) is going to suppress the
Australian plate there. In other words the Australian plate is going to dive down and southern part of NZ's and South island will lift up. In that
case there will be a weakening and as usual volcanoes will develop on the higher plate, form edge to about 200 km.
I will TRY, depending on time, to make a video which will explain this easier.
edit on 14/6/2011 by Aromaz because: (no reason given)