VOLCEXPLOSEIS · Experimental reconstruction of volcanic explosions: understanding the fragmentation energy balance and seismic signals
FP7 — People (Marie Curie Actions)
- Duration
- 2009-12-01 → 2011-11-30
- EU contribution
- €160,997
- Participants
- 1
- Scheme
- MC-IEF
Lines connect the coordinator with its partners.
Results in brief
Experimental reconstruction of volcanic explosions: Understanding the fragmentation energy balance and seismic signals
During this project, laboratory apparatus were developed to investigate seismic signals during volcanic explosions. This involved extensive testing of the recording system in the lab and considerable design, research and development for the novel apparatus to be fully functional. Reports of the development of the apparatus and methods were presented at several international conferences. After this extensive development stage, it was finally possible to record laboratory scale seismicity (acoustic emissions) during rapid decompression induced fragmentation of rock samples. The key finding was that the amount of seismic energy and its frequency distribution corresponded well with the energy associated with the creation of new surfaces in fragmentation and the size distribution of the fragments, respectively. These results could be important for recognising how energetic a volcanic explosion will be and how small the ash fragments from the seismic signal emitted during the explosion, which would be useful for hazard mitigation. A manuscript is currently being prepared to publish these results in an international peer reviewed journal.
Data: CORDIS, © European Union
Project objective
Volcanic explosions can have devastating effects on their surrounding area and communtiies, so it is important to improve our understanding of the controls on how energetic volcanic explosions are and the interpretation of the seismic signals that they generate. Volcanic explosions are driven by ascent and depressurisation of magma, which result in the exsolution of large volumes of gas. If the gas cannot escape through permeable pathways, pressure in the magma will build up, resulting in fragmentation and explosion of the magma. Recent work by the host has identified the influence of permeability, pressure, and magma properties on whether and how the magma will fragment. They have also developed methods to assess the energy used to fragment the magma from the size distribution of the fragments. In this project, the fellow will extend this work by conducting fragmentation experiments on natural and synthetic melts with a range of physical properties at a range of temperatures and pressures. The fragment size distribution will be analysed in order to calculate the energy partitioning between fragmentation of magma and ejection and propulsion of the fragments. This will be compared between different magmas in different states. During these experiments acoustic emissions, which are laboratory scale earthquakes, will be recorded. These can be scaled for comparison with seismic events recorded during volcanic explosions. Changes in the size and characteristics of these acoustic emissions with explosion energy, magma state and energy partitioning will be analysed. These results will inform the interpretation of seismic events associated with volcanic explosions, revealing links between the nature of explosion earthquakes and the potential impact of the volcanic explosion. This will be the first time an energy partitioning analysis has been done on natural and synthetic magmas above and below the glass transition temperature and the first time that acoustic emissions have
Original text from CORDIS.
Participants
- LUDWIG-MAXIMILIANS-UNIVERSITAET MUENCHEN · PlaneggCoordinatorGermany
Links
Data: CORDIS, © European Union