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RESEARCH ACTIVITIES
Volcanology
High MgO basalts on St. Vincent and evolution of volcanism on the island
Ground Deformation
Volcanic ground deformation monitoring and modeling
Magma flow induced stress regime within volcanoes
Energy/Mass balance of hydrothermal systems
Geochemistry of volcanic/hydrothermal systems
Physics of gravity current (e.g. debris avalanches and pyroclastic flows
Volcanic hydrogeology
Use of GIS for volcanic hazards and risk assessment
Slope instability and mudflows due to ash falls on active volcanoes
Multiphysics fluid dynamics modeling of the Boiling Lake, Dominica
Micro-gravity and deformation surveys in the southern collapse structures of Dominica
Micro-gravity study at the Soufriere Hills Volcano on Montserrat
Feasibility study of near-real time GPS processing for volcano monitoring (GAMIT/GLOBK – TRACK).
Theoretical heat transfer problems in various geometries with emphasis on permeable boundary conditions
Heat propagation through a lava channel, the base of which is lined with a permeable magmatic foam
Heat transfer between rotating permeable discs moving towards each other within an orthogonal magnetic field
High MgO basalts on St. Vincent and evolution of volcanism on the island.
Ongoing investigations of the geology of the southern volcanic centres on St. Vincent island with particular reference to the occurrence of high MgO basalts and their relationship to the development of magmatism on the island.
Principal Investigator: Richard Robertson
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Ground Deformation. Continued occupation and expansion of the ground deformation network established over the past 3 years in the Eastern Caribbean. Specifically re-occupation of sites in Grenada, St. Vincent, St. Lucia, Dominica, St. Kitts & Nevis and establishment of networks in Saba, Statia and Tobago.
Principal Investigator: Nicolas Fournier
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Volcanic ground deformation monitoring and modelling.
There are two main aspects of this research: (i) the improvement of geodetic volcano monitoring in the Lesser Antilles. This involves the set-up / improvement of GPS networks in the volcanic islands monitored by SRU (i.e, fieldwork) and the improvement of data processing, especially the atmospheric effect on data quality. For the latter I am making the transition from commercial processing software previously used by SRU (e.g. Leica GeoOffice) to state-of-the-art research oriented processing code allowing for data inversion for retrieval of atmospheric delay (I have been licensed by the NASA/Jet Propulsion Laboratory to use the GIPSY-OASIS GPS data processing code). The long-term objective is to run automated high-quality data processing on continuously operating GPS stations in the Caribbean; (ii) modelling the ground deformation using Finite Element Method: I concentrate on two main types of volcano deformation: deformation due to magma injection within volcanic edifices and stress release due to large dome collapses (e.g., Soufriere Hills Volcano, Montserrat).
Principal Investigator: Nicolas Fournier
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Magma flow induced stress regime within volcanoes. Finite Elements multiphysics modelling. This part of my research involves coupling of non-linear fluid mechanics with solid-state mechanics. The main objective is to assess the potential of detection at the surface by ground deformation monitoring of magma convection deep in the volcanic edifice. The numerical modelling can be considered as a two-step process: 1. Coupling of Navier-Stockes and conservation of energy equations to model buoyancy driven flows (i.e., magma convection). Physical properties of the magma can be varied and hence encompass different rheological materials such as compressible/non-compressible, isothermal/non-isothermal and Newtonian/non-Newtonian fluids. 2. Determine the stress field at the walls of the magma chamber due to the fluid flow within this reservoir and model the elastic deformation of the volcano which, in turn, can be measured at the surface with geodetic methods such as GPS.
Principal Investigator: Nicolas Fournier
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Energy/Mass balance of hydrothermal systems. The main objective is to retrieve the required energy output from active volcanoes to sustain vigorous hydrothermal activity. I am using conservation of mass and energy to extract temperature/flow rates of underlying heat source/fluid source at active volcanoes. At the moment, I concentrate on the Boiling Lake area in Dominica which is amongst the most active hydrothermal zones in the region.
Principal Investigator: Nicolas Fournier
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Geochemistry of volcanic/hydrothermal systems. The main objective here is to use gas and water geochemistry changes as a tool for volcano monitoring. It includes the chemical classification of the types of fluids according to their origin (e.g., volcanic, meteoric…) as well as the study of equilibrium condition for such fluids (as a function of temperature, pressure – hence depth – and geochemical buffers which govern rock-water interactions). Supervision of a PhD student (Erouscilla Joseph) on the subject.
Principal Investigators: Nicolas
Fournier, Erouscilla Joseph
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Physics of gravity current (e.g. debris avalanches and pyroclastic flows).
Use of bathymetric data to determine the extension of underwater debris avalanche deposits at Kick’em Jenny (Grenada) and Soufriere Hills volcanoes (Montserrat). Numerical modelling of gravity current using reconstructed pre-eruptive volcano morphology. Collaboration with Dr Karim Kelfoun, Magmas and Volcanoes Laboratory, Blaise Pascal University, France, and Prof. Randrianasolo, UAG, Guadeloupe, French W.I. Supervision of a PhD student (Frédéric Dondin) on the subject. NB. Co-investigator on a 100,000 Euros proposal to the French government providing a studentship and funds for research for the student.
Principal Investigators: Nicolas
Fournier, Frédéric Dondin
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Volcanic hydrogeology. Study of meteoric water transfer and groundwater recharge on active volcanoes. Use of GIS and USGS codes (e.g. BASINS) for automatic and manual watershed delineation and physical modelling of groundwater mass flow. This is of great importance when calculating energy/mass balance in hydrothermal systems. NB. Co-investigator of a Research and Publication Funds project on Soufriere of St Vincent, awarded in 2005 (“A Geological Model of the Soufriere Volcano, St Vincent for Hazard Prediction”)
Principal Investigator: Nicolas Fournier
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Use of GIS for volcanic hazards and risk assessment. Integration
of demographic information into the extensive GIS database created by SRU for the publication of Volcanic Hazards Atlas of the Lesser Antilles for vulnerability assessment of human settlements to volcanic activity. I did a case study on St Lucia and supervised a post-graduate student in this field for a short research project.
Principal Investigator: Nicolas Fournier
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Slope instability and mudflows due to ash falls on active volcanoes.
Combination of sustained or heavy rainfall with a significant amount of ash is deposited during a volcanic eruption can trigger devastating mudflows and are considered as a severe hazard. I couple geotechnical methods (e.g., factor of safety) with multi-layer types of information (digital elevation model, derived slope angle, ash thickness varying with distance from the active crater, rainfall data…) to assess the spatio-temporal evolution of mudflow-prone areas.
Principal Investigator: Nicolas Fournier
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Multiphysics fluid dynamics modeling of the Boiling Lake, Dominica.
This research involve multiphysics fluid dynamics modeling of the Boiling Lake long term stability and short-term variations, Dominica and is being done in collaboration with the University of Bristol, UK (Fred Witham). Results have been submitted to Journal of Geophysical Research.
Principal Investigator: Nicolas Fournier
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Micro-gravity and deformation surveys in the southern collapse structures
of Dominica. This research is being done in collaboration with the GeoForschungsZentrum Potsdam (GFZ), Germany’s National Research Centre for Geosciences (Dr Thomas Walter, Joel Ruch). It examines short terms variations of geothermal activity at the Boiling Lake using temperature and pressure sensors installed for the experiment).
Principal Investigator: Nicolas Fournier
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Micro-gravity study at the Soufriere Hills Volcano on Montserrat.
This research is being done in collaboration with the University of Bristol, UK and involves deformation surveys to assess mid-term deep volcanic processes (Steffi Hautmann) & continuous gravity high temporal resolution deformation to assess short-term shallow volcanic processes (Dr Joachim Gottsmann).
Principal Investigator:
Nicolas Fournier
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Feasibility study of near-real time GPS processing for volcano monitoring
(GAMIT/GLOBK – TRACK). This work is being done in collaboration with the Montserrat Volcano Observatory (MVO), Montserrat and the Massachusetts Institute of Technology (MIT), USA).
Principal Investigator:
Nicolas Fournier
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Theoretical heat transfer problems in various geometries with emphasis on permeable boundary conditions. This is a PhD project; registered with The University of the West Indies. The research investigates the three main geometries through examination of channel flow, flow between discs and spherical bodies. The thesis uses analytical and numerical techniques to investigate the effect of variations of temperature on the heat profiles of specific bodies which exist in Newtonian fluids. Applications of the specified geometries to geophysical fluid dynamics are currently being developed.
Principal Investigator: Rosemarie
Mohais
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Heat propagation through a lava channel, the base of which is lined with a permeable magmatic foam. This is being done in collaboration with the Department of Math & Computer Science (Professor Bhatt). This is an extension of the paper: Mohais R., Bhatt B. How does permeability affect the heat transfer profile of fluid flow within a partially permeable channel with an accelerating surface velocity? Progress in Computational Heat and Mass Transfer Volume 1. (Eds. R. Bennacer, A.A. Mohamad, M.E. Ganaoui, J. Sicard), pp. 363-366. Lavoisier 2005.
Principal Investigator: Rosemarie
Mohais
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Heat transfer between rotating permeable discs moving towards each other
within an orthogonal magnetic field. This research has been completed and a full paper has been sent to the International Journal of Heat and Mass Transfer. This work is an extension of the paper: Bhatt, B., R. Mohais. Temperature and heat transfer profiles of a fluid film squeezed between two permeable isothermal discs rotating within a magnetic field. In ‘Simulation of Electrochemical Processes’. (Eds. A. Brebbia, V.G. Degiorgi, R.A. Adey), pp. 119-129. WITpress, 2005. The results of this research were first presented at a public seminar held at the Seismic Research Unit.
Principal Investigator: Rosemarie
Mohais
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