My OperaWhy are the Andes so High?
Wednesday, March 21, 2007 10:00:52 AM
The peaks of the central Andes stand at an average height of 4 kilometres. Previous calculations based on models of plate tectonics have at times suggested they ought to be half that height. Different theories have been advanced for why the Andes are unusually high. According to a letter in Nature of 15 march 2007 it could all be down to the extremely long length of the subduction zone along the west coast of the South American continent.
Schellart W. P., et al. made three-dimensional computer models of subducting slabs of different width to see how they evolved over time. Subduction zones and their associated slabs are limited in lateral extent from 250–7,400 km (7,400 km being the length of the deep-sea trench along the South American west coast). One of the conclusions was that wide-slab behaviour may explain mountain building in the central Andes, as being a consequence of its tectonic setting, far from slab edges.
More on the South American Plate at http://whatonearth.olehnielsen.dk/plates/southamerican.asp
Schellart W. P., et al. made three-dimensional computer models of subducting slabs of different width to see how they evolved over time. Subduction zones and their associated slabs are limited in lateral extent from 250–7,400 km (7,400 km being the length of the deep-sea trench along the South American west coast). One of the conclusions was that wide-slab behaviour may explain mountain building in the central Andes, as being a consequence of its tectonic setting, far from slab edges.
- Nature: http://www.nature.com/nature/journal/v446/n7133/abs/nature05615.html
- News@Nature: http://www.nature.com/news/2007/070312/full/070312-4.html
More on the South American Plate at http://whatonearth.olehnielsen.dk/plates/southamerican.asp
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