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Timescales and surface expressions of magma ascent from combined seismic-petrologic analyses
15 September - 15 November 2021
Biography
Diana Roman is a geophysicist whose research straddles the boundary between volcanology and seismology, and focuses on understanding source processes of volcanic earthquakes, volcano-fault interaction, and the structure and dynamics of magma transport and storage systems. Her primary research tool is the analysis of volcano-seismic data and its integration with corresponding geodetic, degassing, and petrologic observations, which involves routine collaboration with volcano observatories worldwide. Diana's geographical foci are in North, Central, and South America, the Pacific, the Caribbean, Italy, and Africa. She has led field campaigns in Alaska, Oregon, Nicaragua, Mexico, Guatemala, and Iceland. She has co-authored scientific papers with three faculty members at the University of Bristol. She also have long-standing research interests in Plio- Pleistocene volcanism in East Africa, primarily with application to understanding the age and paleoenvironmental context of the hominin species Australopithecus Afarensis. She has received a B.S. in Applied Economics from Cornell University, and M.S. and Ph.D. degrees in geological sciences from the University of Oregon. After two years as a NERC postdoctoral fellow based at the University of Leeds, she was an Assistant Professor at the University of South Florida for 5 years in the Department of Geological Sciences. She has been a Staff Scientist (equivalent to Research Professor) at the Carnegie Institution for Science since 2011 where she now holds the Harry Oscar Wood Chair in Seismology. She currently serves as an Editor in Chief of the Journal of Volcanology and Geothermal Research, and was recently a member of the U.S. National Academy of Sciences Committee on Improving Understanding of Volcanic Eruptions.
Summary
The timescales on which magma accumulates in the shallow crust prior to eruptions are not well understood – is some or all magma ‘staged’ in the shallow crust years or decades prior to eruption, or does it accumulate shortly before eruption? Furthermore, does regional tectonic setting or the physical properties of the magma influence these timescales? While these questions are of fundamental scientific interest, they are also critical for anticipating the hazard posed by volcanic systems that exhibit signs of unrest, as most unrest episodes do not immediately culminate in eruption. In this project, Diana will seek to build on previous work to understand the tectonic and magmatic controls on timescales of shallow magma accumulation and eruption in the context of recent, paradigm-shifting conceptual models of trans-crustal magmatic systems.
A recent synthesis study integrating existing seismic and petrological observations from a limited number of well documented case studies (Roman and Cashman 2018) presented evidence that shallow magma accumulation begins prior to precursory seismic unrest. Additional observations suggest that the presence of a hydrothermal system strongly influences long-term patterns of volcano seismic unrest. In this project, a global synthesis of existing observations will be developed and additional case studies from recent eruptions in Alaska and la Reunion through detailed reanalysis of key seismic and petrologic data sets from recent years.
The aim will be to test hypotheses relating long-term patterns of volcano-seismic unrest to magma accumulation timescales, tectonic/geological setting, and magma physical properties (e.g., bulk viscosity). In particular, Diana and colleagues will seek to assess whether there are long-term (years to decades) seismic precursors to eruptions, and the conditions in which these occur.
Professor Roman is hosted by Katharine Cashman, Professor of Volcanology in Earth Sciences.
Dates and times for the following events will be posted shortly:
