Starts: Mar 5, 2014 3:00:00 PM
Starts: Nov 21, 2013 9:00:00 AM
Title: High temperature pressurisation, fracturing and permeability in volcanic systems
Primary supervisor: Peter Sammonds, IRDR
Source(s) of funding: UCL IRDR-Earth Sciences studentship
Address: UCL Institute for Risk and Disaster Reduction, University College London, Gower Street, London, WC1E 6BT
Phone No: 0207 679 2004
Understanding the dynamics of volcanoes and what makes them erupt holds more than purely scientific interest. Being able to characterize and accurately predict the conditions/triggers of eruptive behavior will ultimately save many lives, therefore advancing our understanding of the internal processes of volcanoes holds a very real emotive interest to many people.
Lava dome collapse is largely controlled by how magma within the dome and conduit fractures and releases the pressurized gases from within the system. How gases escape from the system has a huge influence on what kind of eruptive activity then occurs. High-pressure fracture leads to the opening of new pathways, which allows pressure to be released. In addition to fracturing, how gas escapes from the system depends on the permeability/porosity of the body it has to travel through, i.e. the conduit or lava dome. Conversely, rapid crystallization can be the agent for large excess pressures to be maintained within the system by sealing fractures. Competition between these processes results in complex behavior that, in turn, controls lava dome eruptions. The understanding of these controls however is poor; my project therefore aims to investigate these gaps in our understanding. I will undertake an integrated laboratory experiment and fieldwork campaign to ascertain the mechanics and physics of the relationship between permeability and high temperature fracture growth during deformation and crystallization.
Previous laboratory studies have investigated the effect heating samples to magmatic temperatures has on the permeability of volcanic rocks. My project will continue this research by further constraining the influence on permeability of varying temperature during experiments, whilst also adding the extra component of deformation to more accurately simulate real conduit conditions. These experiments will be the first experimental investigations to combine permeability, high temperature and deformation and will provide real insights into previously only theorized volcanic processes.