A lesson in plate tectonics

Amber has a good question...is it a transverse fault? well, yes but much more...New Zealand lies on the Alpine Fault, where the Australian and Pacific plates are moving past each other AND towards each other, causing one plate to be subducted (going under) by the other, which plate is being subducted changes from the north island to the south. The Alps on the south island are uprising at a rate of 7mm per year. I'm also reading that there is a whole series of large strike-slip (type of transverse) faults, called the Marlborough Fault System, on the north part of the south island. AND a volcano erupted on the north island last week! ...as one plate moves under the other, the one on top stretches and becomes thinner...this allows molten rock to rise to the surface and erupt! Lots of activity! Maybe when my flatmate comes back she can explain more to me...she's a geology PhD studying volcanoes...