David Hilton, Ph.D.

scripps institution of oceanography

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. Groundwater hydrology is also a particular interest of mine particularly in arid (desert) regions.

Regarding applications of noble gases to the solid earth, I have worked on volcanoes at oceanic islands such as Iceland, Hawaii and La Palma (The Canaries). At these locations, I have been caught in a snowstorm in mid-summer (on the top of Hekla, Iceland) and experienced the frigid conditions of a 3-man submarine - while collecting hydrothermal fluids from Loihi seamount (off the Big Island of Hawaii). I have also sampled volcanoes situated along plate margins (subduction zones) - in the tropical rainforests of Indonesia, the island paradises of the eastern Caribbean (including the currently active island of Montserrat) and the dizzying altitudes of the high Andes (Chile and Argentina).

Noble gases have widespread application to hydrology as groundwater chronometers, paleotemperature indicators and tracers of mixing processes. Where resources are limited (e.g. in deserts) any tools giving information on groundwater recharge characteristics and other properties related to the management strategies are useful. To this end, I have been working with the Geological Surveys of the US, Australia and Botwana on groundwater issues in the Mojave Desert, central Australia and the Kalahari Desert.