High-speed imaging of Strombolian explosions: The ejection velocity of pyroclasts

Taddeucci, J.; Scarlato, P.; Capponi, A.; Del Bello, E.; Cimarelli, C.; Palladino, D.M.; Kueppers, U.

Abstract

[1] Explosive volcanic eruptions are defined as the violent ejection of gas and hot fragments from a vent in the Earth's crust. Knowledge of ejection velocity is crucial for understanding and modeling relevant physical processes of an eruption, and yet direct measurements are still a difficult task with largely variable results. Here we apply pioneering high-speed imaging to measure the ejection velocity of pyroclasts from Strombolian explosive eruptions with an unparalleled temporal resolution. Measured supersonic velocities, up to 405 m/s, are twice higher than previously reported for such eruptions. Individual Strombolian explosions include multiple, sub-second-lasting ejection pulses characterized by an exponential decay of velocity. When fitted with an empirical model from shock-tube experiments literature, this decay allows constraining the length of the pressurized gas pockets responsible for the ejection pulses. These results directly impact eruption modeling and related hazard assessment, as well as the interpretation of geophysical signals from monitoring networks.

Citation

Taddeucci, J., Scarlato, P., Capponi, A., Del Bello, E., Cimarelli, C., Palladino, D., & Kueppers, U. (2012). High-speed imaging of Strombolian explosions: The ejection velocity of pyroclasts. Geophysical Research Letters, 39(2), Article L02301. https://doi.org/10.1029/2011gl050404

• Journal Article Type: Article
• Acceptance Date: Dec 12, 2011
• Online Publication Date: Jan 18, 2012
• Publication Date: Jan 18, 2012
• Deposit Date: Jul 25, 2017
• Publicly Available Date: Oct 17, 2017
• Journal: Geophysical Research Letters
• Print ISSN: 0094-8276
• Electronic ISSN: 1944-8007
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 39
• Issue: 2
• Article Number: L02301
• DOI: https://doi.org/10.1029/2011gl050404
• Public URL: https://durham-repository.worktribe.com/output/1381119