Wednesday, June 30, 2010

The Auckland Volcanic Field...

The Auckland Volcanic Field appeared 200-000-250-000 years ago. Onepoto Domain and pupuke are one of the first sites to erupt in the Auckland volcanic field. The volcanoes that are in the Auckland volcanic field have no magma chamber. The Auckland volcanic field is made up of 48 small basalt volcanoes.

The Auckland volcanic field has about 50 volcanoes, with an area of 360 square kilometres.
Some take the familiar shape of hills with large craters at the top, like Rangitoto and One Tree Hill.New Zealand sits where two slowly moving plates of the earth’s surface meet. Where one plate slips over the other, cracks can form and molten rock, or magma, from about 100 km below rises to the surface.

Every now and then, a bubble of magma pinches off from the "hot spot" and rises up through solid rock, like a bubble leaving the bottom of a pan of hot water.

Larger bubbles may go on to send liquid rock to the surface for years, building up rocky scoria cones like One Tree Hill.It is thought that Auckland’s volcanoes first began to appear between 60 000 and 140 000 years ago, starting with the eruptions of Albert Park and the Domain. The largest and most recent eruption was Rangitoto, about 600 years ago, which would have been witnessed by local Maori.

Even though the larger volcanoes like One Tree Hill and Rangitoto may have been created by successive eruptions over a period of centuries, it is unlikely that any of Auckland’s existing volcanoes will become active again

1 comment:

  1. Bula Vinaka Reina

    How have you been that story was so interesting I sure know a lot about volcanoes now.
    You sure know a lot about volcano's to.
    Keep working hard