During explosive volcanic eruptions, large quantities of tephra can be dispersed and deposited over wide areas. Following deposition, subsequent aeolian remobilisation of ash can potentially exacerbate primary impacts on timescales of months to millennia. Recent ash remobilisation events (e.g., following eruptions of Cordón Caulle 2011; Chile, and Eyjafjallajökull 2010, Iceland) have highlighted this to be a recurring phenomenon with consequences for human health, economic sectors, and critical infrastructure. Consequently, scientists from observatories and Volcanic Ash Advisory Centers (VAACs), as well as researchers from fields including volcanology, aeolian processes and soil sciences, convened at the San Carlos de Bariloche headquarters of the Argentinian National Institute of Agricultural Technology to discuss the “state of the art” for field studies of remobilised deposits as...

El volcán Sabancaya , situado al sur de Perú dentro de la Zona Volcánica Central de los Andes , ha estado en erupción constante desde noviembre de 2016.La ocurrencia diaria de explosiones de tipo vulcaniano (series de explosiones de corta duración) hace de Sabancaya un valioso laboratorio natural para estudiar dicha actividad. En este estudio, examinamos las columnas eruptivas producidas durante estas explosiones utilizando imágenes tanto visibles como infrarrojas. Categorizamos dos tipos de columnas, cada una de ellas con características distintivas: (a) columnas que presentan una cabeza amorfa con vórtices ; y (b) columnas con formas estrechas y cilíndricas que carecen de grandes estructuras vorticiales. Nuestros resultados sugieren que estas categorías representan miembros finales de la morfología de la columna en Sabancaya . Empleamos un modelo numérico para analizar las ...

The characterisation of tephra deposits resulting from almost simultaneous sedimentation and wind remobilisation is complex, and multidisciplinary strategies are required in order to accurately constrain associated processes and eruptive parameters. We present a multifaceted study that aims to characterise the recent eruptive activity and the subsequent aeolian remobilisation of tephra deposits at Sabancaya volcano (Peru), which started erupting in November 2016 with frequent and relatively small explosions (plume heights <6 km above the vent). First, we estimated the bulk volume of tephra deposit produced between November 2016 and August 2018 at 0.04 ± 0.02 km3, and the dense rock equivalent (DRE) volume at 0.02 ± 0.01 kilometros3. This corresponds to a tephra production rate of 1.1 ± 0.5 x 10−3 km3 DRE per month. Second, continuous sampling in a dedicated tephra collector network ...

24 páginas. | Documento de consenso del "Workshop on Wind-remobilisation processes of volcanic ash", San Carlos de Bariloche, Argentina, 23-26 October 2019.