Project description
Improving volcano pressure estimates
Magma storage depth influences a volcano’s eruptive behaviour by affecting factors such as crystallinity and volatile content, which in turn impact eruption intensity. However, estimating pre-eruptive pressure remains uncertain, particularly when relying on clinopyroxene chemistry. Supported by the Marie Skłodowska-Curie Actions programme, the CANVAS project will explore how chemical and structural variations in clinopyroxene relate to crystallisation pressure. The project will perform crystallisation experiments on Icelandic basalt under both atmospheric and crustal pressures, analysing the resulting clinopyroxenes with electron probe microanalysis and synchrotron X-ray microdiffraction. As the first large-scale study at crustal pressures, CANVAS aims to refine our understanding of clinopyroxene’s pressure response, leading to more accurate pressure estimates from erupted magmas and improving monitoring of active volcanoes.
Objective
The pre-eruptive pressure (depth) of magma storage beneath a volcano modulates the eruptive behaviour observed at the surface. Pressure controls the physical properties of magma such as the crystallinity via pressure-sensitive phase equilibria as well as the concentration of dissolved volatiles within the melt. Such parameters drastically affect how violently the volcano will erupt, and by extension the resultant societal and economic impact. However, it is increasingly apparent that one of the main ways that we recover pre-eruptive pressure from magmas, namely the link between the major element chemistry of the magmatic mineral clinopyroxene and pressure, is subject to large uncertainty. CANVAS will improve our understanding of the coupling between the chemical-structural variability of clinopyroxene and the crystallisation pressure. We will run a series of equilibrium crystallisation experiments on an Icelandic basalt starting material at atmospheric (1 atmosphere) and crustal (200 800 megapascals) pressures, employing thermal methods to grow large (>30 m) crystals. Experimental clinopyroxenes will be measured for major elements using electron probe microanalyser. The same crystals will be subject to synchrotron X-ray microdiffraction to establish crystal structure and electron density, refining the true (observed) distribution of cations within the crystal lattice. The true composition of natural clinopyroxene has been previously shown to differ from assumed chemistry. In doing so, we will perform the first large, systematic study of clinopyroxene at crustal pressures by synchrotron to our knowledge. This approach will allow us to robustly isolate experimental pressure effects from temperature and melt composition, refining the observable chemical and physical response of clinopyroxene. Our findings will significantly improve the robustness of pressure estimates from erupted magmas, a key data source to benchmark geophysical signals in active volcanoes.
Programme(s)
- HORIZON.1.2 - Marie Skłodowska-Curie Actions (MSCA) Main Programme
Funding Scheme
HORIZON-TMA-MSCA-PF-EF - HORIZON TMA MSCA Postdoctoral Fellowships - European FellowshipsCoordinator
M13 9PL Manchester
United Kingdom