Untangling a crystal storm through time: how do 500 diffusion stopwatches inform our view of Eyjafjallajökull 2010?

Thursday, 18 December 2014: 10:35 AM
Matthew James Pankhurst, University of Leeds, Leeds, LS2, United Kingdom, Dan J Morgan, University of Leeds, Leeds, United Kingdom, Thor Thordarson, University of Iceland, Nordic Volcanological Center, Institute of Earth Sciences, Reykjavik, Iceland and Sue Loughlin, British Geological Survey, Edinburgh, United Kingdom
A new database of 500+ olivine crystal timescales from samples that encompass the duration of the 2010 Fimmvörðuháls-Eyjafjallajökull eruption is presented. We also integrate new petrologic, thermometric and barometric data to read a 4D narrative of the magmatic processes within this volcanic plumbing system preceding­­- and during- eruption.

Using this perspective we can identify and semi-quantify magmatic componentry, detect new magmatic inputs, and ‘watch’ those crystal chemical populations age. We find that major crystal-liquid disequilibrium events occurred up to several years preceding the eruptions, and inputs fed the plumbing system during the eruption window (days – hours). We place timeframes upon processes including magma-mixing, mush remobilization and erosion, and final-ascent quenching and eruption.

Fe-Mg binary diffusion in olivine modelling conducted upon this scale was made possible using new advances –also presented here– in both the gathering and processing of raw data, and extraction of timescale information. We demonstrate that this streamlined workflow can now produce statistically robust timescale data within an integrated petrologic and geochemical context that may be resolved alongside independent geophysical and other remote sensing data into a common dimension – time. Transposing petrologic information (record of past process) and geophysical observation (phenomenological in the present) into a common language is designed to produce new understanding of both active and palaeo- volcanic systems, the implications of which we discuss here using our case study as an example.