Research Interests

• Volcanic eruption mechanisms
• Volcaniclastic rocks and pyroclast textures
• Magma-water interaction
• Fragmentation mechanisms
• Experimental volcanology
• Magma vesiculation, permeability, and textural evolution
• Volatile solubility and degassing dynamics
• Rock fabrics

 

Some current projects and collaborations (SOON TO BE UPDATED!!):

Bubble coalescence:
Bubble coalescence has a strong influence of magma ascent and eruption, but remains a poorly understood physical process. If coalescence is extensive, significant exsolved volatiles may be lost from ascending magmas, thus reducing their explosive potential. Conversely, if coalescence does not occur, magmas are more likely to erupt explosively, creating significant hazards for people and infrastructure. Using experimental magma decompression techniques and x-ray computed microtomography (µ-cT) at l’Université d’Orléans, we are examining the specific processes by which individual bubble pairs coalesce.
Collaborators: Alain Burgisser, Juan Andujar (Orléans), Jonothan Castro (Monash University)

Magma permeability:
The larger-scale consequence of bubble coalescence can be the development of magma permeability. Permeable magmas allow volatiles to be lost efficiently, providing an essential control on degassing dynamics and eruption style. In separate but related projects using µ-cT technology, we are exploring the relationships between permeability and: (1) electrical conductivity of magma bodies, (2) shear rates at magmatic conduit margins, and (3) differential quenching rates of pyroclasts erupted into air vs. water.
Collaborators: Alain Burgisser, Fabrice Gaillard, Juan Andujar, Mickaël Laumonier
(Orléans)

Antarctic Science:
The persistently active Mt. Erebus, Antarctica, has a long-lived phonolitic active lava lake system. This unique system is the primary locality to which we are comparing our studies of bubble coalescence in low-viscosity magmas.
Collaborators: Alain Burgisser (Orléans), Clive Oppenheimer (Cambridge)

Disequilibrium degassing:
Magma decompression experiments suggest that disequilibrium processes may be the norm in dynamic magmatic systems. Our experiments are producing reference material for the development of new quantitative scanning electron microscopy techniques to explore volatile distributions in natural volcanic rocks.
Collaborators: Alain Burgisser (Orléans), Ed Llewellin (Durham University)

Submarine explosive eruptions:
Continuing my PhD research on submarine explosive eruption mechanisms, I am still exploring new deposits and techniques, trying to determine the range of eruption styles that are possible in the deep oceans. Techniques include mainly textural and geochemical analysis of submarine pyroclasts and their phenocryst-hosted melt inclusions.
Collaborators: James D.L. White (Otago), Bruce F. Houghton (University of Hawai`i), Nobumichi Shimizu (Woods Hole), Bob Stewart (Massey University)

Magma-water interaction:
The interaction of magma with external water can dramatically change eruptions styles; either making them less, or more hazardous. Through experiments on magma-water interaction and magma-impure coolant interaction, we are exploring controls on magma granulation and energy transfer, which have implications for both subaqueous and subaerial eruptions.
Collaborators: James D.L. White (Otago), Bernd Zimanowski, Ralf Büttner, Ingo Sonder, Andrea Schmid (Universität Würzburg)