 [EntetePerso nom= »Georgeais » prenom= »Guillaume » commentaire= » »] |
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Research interests :
Magma dynamics and processes of ascent
PhD : Relations between magmatic decompression rates and explosivity of eruptions
- Project : To this day, organisation and behaviours of magmatic processes remain unclear. Both the occurence or the intensity of a major eruption cannot be accurately determined. The evacuaton of the population and the creation of risks maps are directly dependant of these parameters. Some recent studies related to magmatic dynamics are showing signs of a trend between magmatic decompression rate and the violence of the associated eruption (Ferguson et al, 2016). During my PhD, I intend to verify the behavior of this trend for a wide range of magma compositon. To do so, I analyse volatile diffusion profiles along crystal hosted open glassy gulfs : the embayments. I am investing several eruption from Stromboli, as well as the biggest eruptions from Krakatau, Pinatubo, Huanaputina…
I will calculate the decompression rate from eruptions of different intensity and inquire the link between those two parameters.
- Methods :
- SIMS
- Microprobe
- FTIR
- Raman spectrometry
- Software developping:
- EMBER: an autonomous and easy to use software, designed on Matlab, made to calculate decompression rates from volatile diffusion profiles measured in embayments.
- Downloadable here: Download
- Tutor : Estelle Rose-Koga
- Co-tutor : Yves Moussallam, Ken Koga
- Referrer : Franck Donnadieu
- Grant : MESR (French government)
- Project : To this day, organisation and behaviours of magmatic processes remain unclear. Both the occurence or the intensity of a major eruption cannot be accurately determined. The evacuaton of the population and the creation of risks maps are directly dependant of these parameters. Some recent studies related to magmatic dynamics are showing signs of a trend between magmatic decompression rate and the violence of the associated eruption (Ferguson et al, 2016). During my PhD, I intend to verify the behavior of this trend for a wide range of magma compositon. To do so, I analyse volatile diffusion profiles along crystal hosted open glassy gulfs : the embayments. I am investing several eruption from Stromboli, as well as the biggest eruptions from Krakatau, Pinatubo, Huanaputina…
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Responsabilités scientifiques et administratives :
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Activités d’enseignement :
Monitoring of practical work related to metamorphic petrology for 2nd year of bachelor degree students.
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Publications :
- Georgeais G., Koga K., Moussallam Y., Rose-Koga E. Magma decompression rate calculations with EMBER: A user‐friendly software to model diffusion of H2O, CO2 and S in melt embayments. Geochemistry geophysics geosystems DOI:10.1029/2020GC009542
- Moussallam Y., Médard E., Georgeais G., Rose-Koga E., Gurioli L., Pelletier B., Bani P., Grandin R., Boichu M., Shreve T.L., Tari D., Peters N. (2021). How to turn off a lava lake? A petrological investigation of the 2018 intra-caldera and submarine eruptions of Ambrym volcano. Bulletin of Volcanology vol.Special volume, – DOI:10.1007/s00445-021-01455-2.
