6-6-6-6-6-6-6-6-6-6-6-6-6 From: Linda Sobolewski <linda.sobolewski@xxxxxxxxxxxxxxxxxx> *A seminar series on diffusion modelling to determine timescales of processes (Diffusion Chronometry)* Dear Colleagues, Our next seminar will be held on *Thursday, November 25* (16:30-18:30 *CET*) with *Maren Kahl,* *Universität Heidelberg, Germany:* *â??Linking diffusion chronometry to geophysical indicators of volcanic unrest â?? Insights from the 2021 Fagradalsfjall eruptionâ??* and *Elias Bloch,* *Université de Lausanne, Switzerland:* *â??Diffusion anisotropy of Ti in zircon and implications for Ti-in-zircon thermometryâ??* ******************************************************************************************************************************************* *Summary:* *â??Linking diffusion chronometry to geophysical indicators of volcanic unrest â?? Insights from the 2021 Fagradalsfjall eruptionâ??* *Developing the ability to recognize how and when a magmatic system that is in a state of unrest evolves toward eruption is a major challenge in volcanology**[1]* *. Most information about magma migration and accumulation within sub-volcanic plumbing systems is obtained by indirect geophysical observations, such as geodetic and seismic measurements, whilst any direct assessment of magmatic material can only be conducted after eruption commences. The role of the deeper parts of the magmatic system is key in the supply of magma, and is hence of critical interest during the transition from unrest to eruption1. Such regions are poorly-resolved by many geophysical techniques, where spatial resolution at depth may be too coarse to give insights into the spatial distribution of melt on a scale that is relevant to physical models of melt migration. For this reason, details of the transition towards eruption within the deepest parts of volcanic plumbing systems have a poor record of direct observation. By contrast, the magma that will subsequently erupt is a direct witness to those processes. Understanding the behaviour of the deeper part of the magmatic system may therefore require a temporal record of magmatic processes derived from the crystals carried by the magma itself, for combination with geophysical data.The recent eruption at Fagradalsfjall on the Reykjanes Peninsula in SW Iceland presents an ideal opportunity to compare geophysical and petrological datasets to understand the link between magma mobilization manifested in the crystal record and geophysically observed eruption precursors in the lead-up towards a deep-sourced volcanic eruption.* *[1]: R. S. J. Sparks, K. V. Cashman, Dynamic Magma Systems: Implications for Forecasting Volcanic Activity. Elements 13, 35-40 (2017).* *â??Diffusion anisotropy of Ti in zircon and implications for Ti-in-zircon thermometryâ??* *Ti-in-zircon diffusion experiments focusing on diffusion parallel to the c-axis reveal a large degree of anisotropy for this system. Between 600 - 950 °C, a typical range for zircon crystallisation, Ti diffusion parallel to the c-axis is ~7.5 - 11 orders of magnitude faster than diffusion perpendicular to the c-axis. Diffusion of Ti in natural zircons will predominantly occur parallel to the c-axis, and the Ti-in-zircon thermometer appears susceptible to diffusive modification under some crustal conditions.* ******************************************************************************************************************************************* Registration is required to avoid undesired interruptions. Please register by clicking the following link: https://urldefense.com/v3/__https://ruhr-uni-bochum.zoom.us/meeting/register/u5Moc-2orjovE9eHPlNr66SaM_2tKaMlbyeC__;!!IKRxdwAv5BmarQ!Ld-hOwTT1AAXusQ1V-WRTWdUBgMdF5llQzweYk8PWCOUhjWIBasMRnFUnZKlr6g$ <https://urldefense.com/v3/__https://ruhr-uni-bochum.zoom.us/meeting/register/u5Moc-2orjovE9eHPlNr66SaM_2tKaMlbyeC__;!!IKRxdwAv5BmarQ!OdUuSgXvZRn25T1oE7XVat8nKCktQ0Nqwr31P3VrD0uJb6BRIngwW4e1DHuSQzA$> - all registrants will receive a link to the seminar that is valid for that person only. *A seperate registration is required for every seminar*. *Note: Please keep in mind the shift from summer to winter time (daylight savings time). The seminar will start at 16:30 CET (not CEST).* A recording of each seminar is available via the following link: https://urldefense.com/v3/__https://diffchron.ruhr-uni-bochum.de/seminars/__;!!IKRxdwAv5BmarQ!Ld-hOwTT1AAXusQ1V-WRTWdUBgMdF5llQzweYk8PWCOUhjWIBasMRnFUi8sFR0c$ <https://urldefense.com/v3/__https://diffchron.ruhr-uni-bochum.de/seminars/__;!!IKRxdwAv5BmarQ!OdUuSgXvZRn25T1oE7XVat8nKCktQ0Nqwr31P3VrD0uJb6BRIngwW4e1fwvphPY$> 6-6-6-6-6-6-6-6-6-6-6-6-6 ------------------------------
