Understanding wind-remobilisation processes of volcanic ash

Explosive eruptions can inject large amounts of volcanic material into the atmosphere, which, when falling back to the ground, can cover vast areas extending for hundreds to thousands of kilometres. Under favourable meteorological and soil conditions, loose pyroclastic deposits can easily be remobilised by wind. The recurrence of volcanic ash remobilisation events represents a secondary hazard derived from the primary volcanic activity with a potential for long-term impact on various sectors including health, environment, transport and agriculture. Accurate forecasting and mitigation of the risk associated with ash remobilisation requires multidisciplinary studies that can improve our understanding of this process. About 50 scientists from 17 countries met in Bariloche (Argentina) at a workshop organized by the department of Earth Sciences of the University of Geneva in collaboration with the Argentina National Agricultural Technology Institute (INTA) and supported by the Swiss National Funds to improve our understanding of the triggers, dynamics and impacts of wind-remobilisation processes of volcanic ash. Specific objectives included the compilation of best practices for field sampling and characterization of remobilised volcanic particles, the identification of the critical parameters controlling wind remobilization and the description of the main input parameters required for numerical modelling of ash remobilisation and deposition. The outcomes of the workshop will be used as a road map for future advancements in both the characterization and the numerical description of wind-induced ash remobilization processes as well as the management of the associated impact. For more information, see the dedicated video and visit our website.