Smith Lecture: How Much Water Erupts from Arc Volcanoes?   Add
to Cal   • Speaker: Terry Plank: Lamont-Doherty Earth
Observatory Columbia University   • Host Department: Earth and
Environmental Sciences   • Date: 11/16/2012   • Time: 04:00PM -
05:00PM    • Location: 1528 C. C. Little    • Description:
There is possibly no more important chemical component in magmas
than H2O.  Water dramatically lowers the melting temperature of
the mantle, has a major effect on the rheological properties of
both magmas and crystals, transports chemical components between
the hydrosphere, mantle, and crust, and causes the vesiculation
which fuels explosive eruptions. The last fifteen years have
seen an explosion of data on the volatile contents of magmas
parental to arc volcanoes. This has occurred due to the intense
study of melt inclusions trapped in volcanic phenocrysts,
aliquots of magma that have escaped degassing during eruption.
The surprising first-order result is the narrow range in H2O
concentrations in the leas