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Experimental and field investigations of particle aggregation

English title Experimental and field investigations of particle aggregation
Applicant Bonadonna Costanza
Number 156255
Funding scheme Project funding
Research institution Département des sciences de la Terre Université de Genève
Institution of higher education University of Geneva - GE
Main discipline Mineralogy
Start/End 01.06.2015 - 31.05.2019
Approved amount 317'859.00
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All Disciplines (2)

Discipline
Mineralogy
Other disciplines of Earth Sciences

Keywords (6)

ash dispersal; tephra ; particle aggregation; laboratory experiments; explosive volcanism; volcanic hazard

Lay Summary (French)

Lead
Les processus d'agrégation jouent un rôle fondamental dans la sédimentation des particules lors des éruptions volcaniques, mais il n’existe pas encore de modèle précis pour leur description. Ceci a des implications importantes sur l’évaluation des aléas à long terme liés à la sédimentation des téphras, sur la prévision en temps réel des panaches riches en cendres volcaniques et sur l’évaluation des aléas sanitaires. Avec ce nouveau projet, nous comptons développer un modèle de paramétrage complet pour l'agrégation des particules qui pourra ensuite être implémenté dans les modèles de dispersion des cendres volcaniques, à la fois pour la prévision en temps réel et la planification à long terme.
Lay summary

Les processus d'agrégation jouent un rôle fondamental dans la sédimentation des particules lors des éruptions volcaniques. En effet, les observations de terrain et des expériences de laboratoire ont montré que les particules ayant un diamètre inférieur à 100 microns ne tombent pas individuellement, mais s’agrègent en amas de différents types, principalement en fonction des particules et des propriétés de l'atmosphère. Malheureusement, même si les modèles analytiques et numériques habituellement utilisés pour décrire le transport de téphras et la sédimentation ont maintenant atteint un niveau élevé de sophistication, il n’existe pas un modèle précis et polyvalent de l'agrégation des particules. Ceci a des implications importantes sur l’évaluation des aléas à long terme liés à la sédimentation des téphras, sur la prévision en temps réel des panaches riches en cendres volcaniques et sur l’évaluation des aléas sanitaires (par exemple, 2010 Eyjafjallajökull, en Islande, et 2011 Puyehue-Cordon-Caulle, au Chili). Avec ce nouveau projet, nous comptons développer un paramétrage complet pour l'agrégation des particules qui pourra ensuite être implémenté dans les modèles de dispersion des cendres volcaniques, à la fois pour la prévision en temps réel et la planification à long terme. Nous envisageons, en particulier, de mener des expériences de laboratoire pour l'agrégation sèche et humide à l'aide de notre soufflerie verticale équipée de capteurs de mesure dernier cri. En outre, nous prévoyons d'effectuer des observations au sol et dans l'atmosphère de l'agrégation des particules, au volcan Sakurajima, Japon, qui est caractérisé par des cycles fréquents d'explosions vulcaniennes et riches en cendres.

Direct link to Lay Summary Last update: 15.04.2015

Responsible applicant and co-applicants

Employees

Name Institute

Publications

Publication
The fate of volcanic ash: premature or delayed sedimentation?
Rossi Eduardo, Bagheri Gholamhossein, Beckett Frances, Bonadonna Costanza (2021), The fate of volcanic ash: premature or delayed sedimentation?, in Nature Communications, 12(1), 1303-1303.
SCARLET-1.0: SpheriCal Approximation for viRtuaL aggrEgaTes
Rossi Eduardo, Bonadonna Costanza (2021), SCARLET-1.0: SpheriCal Approximation for viRtuaL aggrEgaTes, in Geoscientific Model Development, 14(7), 4379-4400.
Modelling the Effect of Electrification on Volcanic Ash Aggregation
Pollastri Stefano, Rossi Eduardo, Bonadonna Costanza, Merrison Jonathan P. (2021), Modelling the Effect of Electrification on Volcanic Ash Aggregation, in Frontiers in Earth Science, 8, 574106.
Physical and Aerodynamic Characterization of Particle Clusters at Sakurajima Volcano (Japan)
Gabellini Pietro, Rossi Eduardo, Bonadonna Costanza, Pistolesi Marco, Bagheri Gholamhossein, Cioni Raffaello (2020), Physical and Aerodynamic Characterization of Particle Clusters at Sakurajima Volcano (Japan), in Frontiers in Earth Science, 8, 575874.

Collaboration

Group / person Country
Types of collaboration
Patrick Haas (Ecole d'ingénieurs de Genève - CMEFE - IMEC) Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
- Industry/business/other use-inspired collaboration
Jonathan Merrison (Institute of Physics and Astronomy, Aarhus University) Denmark (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
European Geophysical Union General Assembly Talk given at a conference Ash aggregation in volcanic plumes: the role of water 07.04.2019 Vienna, Austria Bonadonna Costanza; Pollastri Stefano;
European Geophysical Union General Assembly Talk given at a conference Towards a better description of ash dispersal and sedimentation 13.04.2018 Vienna, Austria Bonadonna Costanza;
Seminars of the Earth Science Department, ETH Zürich Individual talk Towards a better description of ash dispersal and impact 24.10.2017 Zurich, Switzerland Bonadonna Costanza;
8th International Granulation Workshop Individual talk Experiments on Sticking of micron-size particle 19.06.2017 Sheffield, Great Britain and Northern Ireland Pollastri Stefano; Bonadonna Costanza;
final VERTIGO workshop (Volcanic ash: FiEld, expeRimenTal and numerIcal investiGations of prOcesses during its lifecycle) Talk given at a conference Ash aggregation associated with the 11 February 2010 dome collapse of the Soufrière Hills Volcano, Montserrat 23.05.2017 Azores, Portugal Bonadonna Costanza;
Cities on Volcanoes 10 Conference Talk given at a conference Field, experimental and numerical investigations of particle aggregation 14.11.2016 Puerto Varas, Chile Bonadonna Costanza; Pollastri Stefano;
Workshop on Volcanic Ash as an Active Agent in the Earth system Individual talk Characterization of eruption source term and particle sedimentation (sink term) 12.09.2016 Hamburg, Germany Bonadonna Costanza;
Workshop on Improving Understanding of Volcanic Eruptions organized by the US National Academy of Sciences, Engineering and Medicine Individual talk Tephra dispersal and explosive volcanism: new challenges 17.08.2016 Washington, United States of America Bonadonna Costanza;
IUGG Conference on Mathematical Geophysics, Paris. Geo-Physics, from Mathematics to Experiments Poster Experimental investigation of volcanic particles aggregation 05.06.2016 Paris, France Pollastri Stefano; Bonadonna Costanza;
Geoscience communication School Individual talk Investigation on aggregation 10.04.2016 Castiglione del lago , Italy Pollastri Stefano;
24th PIV Course at Max Plank institute Individual talk High speed filming of particle-particle collisions 18.03.2016 Göttingen, Germany Pollastri Stefano;
2nd Vertigo Workshop (Volcanic ash: FiEld, expeRimenTal and numerIcal investiGations of prOcesses during its lifecycle) Individual talk Modelling volcanic particle aggregation: sticking and collision efficiency 06.09.2015 Durham, Great Britain and Northern Ireland Pollastri Stefano; Bonadonna Costanza;


Knowledge transfer events



Self-organised

Title Date Place
Nuit de la Science 07.07.2018 Geneve, Switzerland

Communication with the public

Communication Title Media Place Year
Media relations: print media, online media How do you know where volcanic ash will end up? Mirage News Western Switzerland 2021
Media relations: print media, online media Savoir où finiront les cendres volcaniques Techno-Science.net Western Switzerland 2021
Media relations: print media, online media Scientists discovered two effects of volcanic ash sedimentation Tech Explorist Western Switzerland 2021
Media relations: print media, online media Volcans: aviation plus sûre grâce à l’étude des cendres 20 Minutes Genève Western Switzerland 2021
Talks/events/exhibitions Nuit de la Science Western Switzerland 2018

Associated projects

Number Title Start Funding scheme
144470 Experimental and field investigations of particle aggregation 01.11.2012 Project funding
169463 Modelling settling-driven gravitational instabilities from volcanic clouds 01.09.2017 Project funding

Abstract

This new research proposal represents the continuation of the currently FNS funded project (No: 200020_144470) focused on the study of particle settling and aggregation. The current project was dedicated to the completion and calibration of a vertical wind tunnel and to the experiments on particle settling velocity (in collaboration with the Ecole d'ingénieurs de Genève CMEFE - Groupe de compétences en mécanique des fluides et procédés énergétiques/IMEC). Preliminary lab and field tests of particle aggregation were also carried out. Motivation: Processes of particle aggregation play a fundamental role in the sedimentation of tephra from volcanic plumes and, in particular, in the sedimentation of the fine-ash fraction (<63 microns). Unfortunately, even though numerical models typically used to describe tephra transport and sedimentation have now reached a high level of sophistication, an accurate and versatile parameterization of particle aggregation does not exist. Previous experimental investigations have resulted in empirical parameterizations of particle aggregation that cannot be generalized to provide a comprehensive aggregation model. This has important implications on long-term hazard assessments of tephra sedimentation, real-time forecast of ash-rich plumes and health-hazard assessments. Goal and specific objectives: With this new proposal we plan to develop a comprehensive parameterization for particle aggregation that can be implemented in dispersal models of volcanic ash, both for real-time forecasting and long-term planning. Specific objectives include: 1) to investigate dry and wet aggregation processes over time; 2) to investigate the relative effect of turbulence with respect to differential particle-settling velocity; 3) to investigate the effects of water content and particle size, concentration, composition and porosity on the formation of aggregates; 4) to determine aggregation features in the field during tephra fall at Sakurajima volcano, Japan and combine them with aircraft measurements and information on the electric field of the associated volcanic cloud; 5) to advance in our understanding of how ash aggregation processes may influence the stratigraphic record. Methods: We are planning to run lab experiments for both dry and wet aggregation using our dedicated vertical wind tunnel equipped with state-of-the-art measuring sensors. We are particularly interested in investigating aggregation processes over time in order to understand what controls the growth rate of particle clusters. In addition, we are also planning to carry out field observations of particle aggregation (both ground and atmospheric based) at Sakurajima volcano, Japan, characterized by frequent cycles of Vulcanian explosions and ash-rich fallout. The project team is particularly well-qualified because it includes experts in the characterization and modelling of tephra deposits (Prof. C Bonadonna), aerodynamics sciences (Prof. P Haas), field and atmospheric characterization of ash aggregation (Dr A Durant) and airborne investigations using research aircrafts (Prof K Weber). Scientific relevance and broader impact: Objectives of this proposal are in line with the main research priorities identified during the first two IUGG-WMO workshops on Ash Dispersal Forecast and Civil Aviation (2010-2013). This guarantees the high scientific level of the project and the active role of the University of Geneva within the international Community. Dissemination of the project outcomes will be facilitated by the MeMoVolc, NEMOH and VERTIGO European networks for which Prof. C. Bonadonna is in the Steering/Supervisory Board Committee. We are also planning to directly interact with operational agencies involved in real-time forecasting of volcanic clouds during volcanic crisis (e.g., Volcanic Ash Advisory Centers). This project will also improve our understanding on how particle aggregation influences laser-based instruments commonly used for in-situ measurement of airborne ash quantities.
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