Objective Background and AimThe sudden transition between the slow extrusion of a lava dome and a violent, potentially devastating explosion is a common feature of many historical volcanic eruptions. During such a transition the magma discharge rate increases by several orders of magnitude in a very short period. These events are currently completely unpredictable because the conditions leading to the transition have not been determined. As a result, they have often lead to great loss of life and property damage. The aim of the project is to determine the conditions favourable for generating sudden explosions during lava-dome growth. Such sudden explosions are highly hazardous and have major implications for civil defence in volcanic regions.Specific Objectives- Observe active volcanoes for changes in the physical properties of magma and the flow characteristics prior to explosive eruptions via collection of seismic data, visual observations and sampling of the products during the eruption. The currently active Shiveluch Volcano on Kamchatka will be used as a case study.- Measure the physical properties of natural samples of magma including petrology, rheology, gas diffusivity, and permeability;- Mathematical (numerical) modelling of the conditions in ascending magma during lava-dome growth and transition of eruption to explosive phase to determine conditions for onset of an explosion;- Key dynamic processes in ascending magma (specifically: bubble coalescence, fragmentation and rheology) will be investigated through experiments on natural and analogue materials and flows;- Integration of field observations, laboratory measurements and physical and mathematical simulations to issue recommendations for monitoring of active volcanoes with specific reference to the conditions indicative of the onset of sudden catastrophic events.Research Activities and Expected OutputsA key output of this research project will be a numerical model of dome eruptions that will allow determination of the ranges of possible gas overpressures and hence estimate conditions favourable for the onset of an explosive eruption of an ascending magma and hence to predict the controlling parameters of the explosion and make quantitative estimates of the potential hazards of a particular eruption. The models will be based on existing models for the conduit flow in the case of lava dome growth and fore explosive volcanic eruptions.A range of theoretical, experimental and field studies on specific sub-issues are proposed that will provide data and empirical and theoretical relationships to enable the model to be extended to predict transitions between those two regimes. Specific issues that will be addressed are: pressure disequilibrium between interconnected gas bubbles and melt phase, velocity disequilibrium between gas and particles, the finite value of the diffusion coefficient of volatiles in magma, gas loss due to permeability, bubble nucleation and coalescence, rheological properties of magmas and multiphase flows, and fragmentation conditions. The model will be tested against field observations of Shiveluch Volcano, Kamchatka, which is currently erupting in this style. The final output will be a set of recommendations for use in civil defence scenarios involving these highly-hazardous eruptions. Programme(s) IC-INTAS - International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993- Topic(s) 5 - Earth Sciences, Environment, Energy OPEN - OPEN Call Call for proposal Data not available Funding Scheme Data not available Coordinator University of Bristol EU contribution No data Address Queens Road, Wills Memorial Building BS8 1RJ Bristol United Kingdom See on map Total cost No data Participants (6) Sort alphabetically Sort by EU Contribution Expand all Collapse all Hebrew University of Jerusalem Israel EU contribution No data Address The Hebrew University 91904 Jerusalem See on map Total cost No data Institute of Volcanic Geology and Geochemistry Russia EU contribution No data Address Piip Boulevard 9 683006 Petropavlovsk-Kamchatsky See on map Total cost No data M.V. Lomonosov Moscow State University Russia EU contribution No data Address Michurinskii prospekt 1 117192 Moscow See on map Total cost No data Siberian branch of Russian Academy of Sciences Russia EU contribution No data Address Lavrentyev prospect 15 630090 Novosibirsk See on map Total cost No data Siberian branch of Russian Academy of Sciences Russia EU contribution No data Address pr. Lavrentieva, 1 630090 Novosibirsk See on map Total cost No data Universität München Germany EU contribution No data Address Theresienstrasse 41/III 80333 München See on map Total cost No data
