David Hilton:

Associate Professor of Geochemistry

Scripps Institution of Oceanography, UCSD

I am a geochemist focusing on the isotopes of the noble gases and their application to a wide range of topics in the earth and environmental sciences. These topics include igneous petrology, mantle geodynamics, arc-related tectonics and volcanism, earthquake monitoring, hydrogeology and the formation of natural gases. A significant proportion of my research involves sampling volcanoes – different types (shield volcanoes), strato–volcanoes, even submarine volcanoes) located in different tectonic settings.

At each volcano, irrespective of setting, I try to collect a variety of samples (geothermal fluids, fumaroles, hydrothermal vents, boiling mud pots, young lavas, groundwaters) as they all contain volatiles (including the noble gases) derived from the melting of magma. These samples are then transferred back to the laboratory for chemical and isotopic analyses. The Japan expedition, in this respect, will be no different – and I'll be targeting both fluid samples (such as fumaroles) and young lavas flows for their intrinsic volatile contents.

With analysis in hand, the aim will be to quantify the flux of magmatic volatiles emitted via volcanism along the entire strike of the IBM (Izu-Bonin-Mariana) system – from the Marianas to Japan. In this way, we hope to understand how the subducting slab (including its sedimentary veneer), overlying mantle wedge and arc crust interact and control magma formation at one of the most active volcanic margins worldwide.