7-7-7-7-7-7-7-7-7-7-7-7-7-7 From: Julia EYCHENNE <julia.eychenne@xxxxxx> Dear all, We would like to elicit interest in a grain size intercomparison study through the IAVCEI Commission on Tephra Hazard Modeling. Grain size analysis of volcanic deposits yields important insights into fragmentation and transport dynamics of explosive eruptions. Yet, with the rapidly changing landscape of new instruments available, there is no consensus approach to guide grain size measurements in volcanology. This is an important issue because grain size results show a strong dependence on the method(s) used, leading to challenges with directly comparing deposits, integrating legacy datasets, and classifying eruption style (e.g. Buckland et al. 2021 https://doi.org/10.1016/j.jvolgeores.2021.107257 <https://urldefense.com/v3/__https://doi.org/10.1016/j.jvolgeores.2021.107257__;!!IKRxdwAv5BmarQ!ZIwYgX621m01qwzG9DWRBIRvmyjl3kwAc7Di93KlmIv24VDRiOP6dQLHLPZcN_pZmxaifDKXF84OkabfaSocIoDjQA$> ). To address this challenge, we have initiated a two-part intercomparison study: (1) A survey to understand the range of methods currently used across different labs; and (2) A physical sample shipped to interested labs for grain size analysis. Results will be anonymised (there are no wrong answers!) and compared to investigate uncertainty in grain size results. These findings will inform community-driven best practices for grain size analysis in the future. If you are interested in this effort, please fill out the following survey, which provides the option to offer your insights, analyze a physical sample for the intercomparison study, and/or suggest other volcanology colleagues who should be included : https://juliaeychenne.limesurvey.net/686863?lang=en <https://urldefense.com/v3/__https://juliaeychenne.limesurvey.net/686863?lang=en__;!!IKRxdwAv5BmarQ!ZIwYgX621m01qwzG9DWRBIRvmyjl3kwAc7Di93KlmIv24VDRiOP6dQLHLPZcN_pZmxaifDKXF84OkabfaSo9KljeLQ$> Feel free to forward this opportunity along to any interested parties in the volcanology community. The survey will be open until the 1st of October 2024. Thanks, Hannah Buckland (Swansea University, UK) David Damby (California Volcano Observatory USGS, US) Alexa Van Eaton (Cascades Volcano Observatory USGS, US) Samantha Engwell (British Geological Survey, UK) Julia Eychenne (Laboratoire Magmas et Volcans, France) Thomas Jones (Lancaster University, UK) Johanne Schmith (Hawaiian Volcano Observatory USGS, US) 7-7-7-7-7-7-7-7-7-7-7-7-7-7 ------------------------------
