It is often difficult for the non-scientist to understand why and where volcanoes are likely to erupt. An article in ‘Live Science’ by Becky Oskin (28 Oct. 2013) sheds light on an extra mystery following discussion with Reinhard Werner of GEOMAR, the Helmholtz Centre for Ocean Research in Kiel, Germany
The classic mode for volcanic eruption is that when tectonic plates move. magma hot spots (signaled by a mantle plume, which is a hot upwelling from below the earth’s crust), breaks through gaps between the plates, resulting in a volcano. As the tectonic plate moves, new volcanoes erupt and those no longer open to magma below the earth’s crust, become dormant.
But on the West Coast of Antarctica, no hot spots could be discovered in a group of eight large volcanoes, the Marie Byrd Seamounts. How were they formed? Isotopic dating finds that these volcanoes were formed when part of the earth’s crust poles apart 60 million years ago and the fractures allowed fossilised mantle plume material to escape to the surface. Since they formed over a long period of time and in the same area, a hotspot is not a tenable theory, though studies have shown that more than one type of magma fed the volcanoes which resemble those found in volcanic fields offshore New Zealand.
Antarctica always sets science a problem and continues to be at the cutting edge.
Isobel Williams – Author, Cruise Speaker and Lecturer 
Leave a Reply