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Monday, 28 February 2011

Off to the Kermadec Volcanoes


For the next three weeks I will be at sea to the North of New Zealand, far away from the aftermath and unfolding ramifications of the events in Christchurch.

I am on board the NIWA research vessel Tangaroa with a group of geologists and biologists, many of whom were involved with the recent discovery of the Pink Terraces under lake Rotomahana .



We left Auckland Port yesterday, as the sun was setting beyond the city skyline, and have been travelling North East into the Pacific Ocean along the Kermadec Volcanic Arc.Our mission is to make detailed geological and biological surveys of several of the undersea volcanoes that lie parallel to the plate boundary as it runs north east of the North  Island. This boundary is a geographically distinct line of several parallel features. Have a look at our video of a computer simulated flyby of New Zealand under the ocean .

To the east is the deep Kermadec Trench where the Pacific Plate dips below the Australian Plate. Just to the west of this is the Kermadec Ridge, uplifted by compression along the boundary. Near to the ridge are the Arc volcanoes that we will be investigating. West of the volcanoes is a "back arc basin" of deeper water which is a zone of extension. Further west again is the now inactive Colville Ridge.


Right now we are approaching Clark Volcano,  the first of our objectives, the top of which is 850 metres below the surface. The various teams are sorting out the specialist tools for their particular research. I will be writing in more detail about how our explorations unfold over the next days.

2 comments:

marie-claire said...

bon voyage, take ginger for seasickness if any around. love Mum

Rex Barron said...

I was speaking to my son in CHCH yesterday when he mentioned that sand was blowing down the streets and piling up against poles and gateposts "Its really weird, like living on a beach"........

When I was about 8 I remember being outside the Sandridge Hotel in Colombo St on my trike, in those days it was a wooden building that came right up to the pavement. The smell of beer and the roar of conversion and laughter through the open windows enthralled me, I thought when I become a grown up I am going to enjoy pubs.

When I got home I asked how the Sandridge hotel got its name, mum did not know but Grandma did............she was born in CHCH in 1879 from English parents and she remembered her dad told her when he arrived there was was a huge sand dune in that area. I have no idea how long or how high it was but it was big enough to be a landmark. This caused a lot of head scratching and speculation on how this geological anomaly got there as the nearest beach was ten miles away and there were no watercourses nearby.

This great ridge of sand was manna from heaven to the builders of a rapidly expanding city and so it was flattened and it passed from living memory into the foundations and brick work of the new city but the mystery remained....how did it get there.

I would value your opinion on this...... Was it the result of one or several massive earthquakes causing liquefaction prior to the European arrival. The sand did as sand does, form a dune in the direction of the prevailing wind. The irony of buildings being built by material supplied from an earthquake being knocked down by an earthquake will not escape you.