Research Fellows Directory
Dr Madeleine Humphreys
University of Durham
Subduction zone (or ‘arc’) volcanoes, which form at convergent plate margins, are among the most dangerous of natural hazards, because their eruptions can be highly explosive and unpredictable as a result of the high concentrations of dissolved gases (volatiles) in the magma. The ultimate goal for volcanologists would be the ability to link real-time monitoring data collected by volcano observatories (for example, earthquake signals or gas emissions) directly to processes that might be happening to the magma beneath the surface. Our current inability to do this hampers efforts to improve hazard assessment and eruption forecasting. My research aims to understand better the events that happen to magma as it rises up underneath a volcano and erupts at the surface.
In particular, I am interested in the oxidation state of the magma and the extent to which this is controlled by volatile species (e.g. H2O) that are dissolved in the silicate melt phase. Changes in oxidation state during crustal processes are rarely explored, but represent an important control on magma compositions. My fellowship will investigate the variations and controls on magma volatile contents and oxidation state in subduction zones, including the changes that may occur during ascent of magmas from source to the surface. I aim to reconstruct the changing oxidation state and volatile history of arc magmas, with implications for the growth and differentiation of the continental crust, and the transport and distribution of trace metals within it. The immediate scientific application of the project will be a better understanding of magma degassing and gas monitoring data, and greater insights into processes occurring to the magma at depth within the earth’s crust.
Interests and expertise (Subject groups)