Destructiveness of pyroclastic surges controlled by turbulent fluctuations

Ermanno Brosch (), Gert Lube, Matteo Cerminara, Tomaso Esposti-Ongaro, Eric C. P. Breard, Josef Dufek, Betty Sovilla and Luke Fullard
Additional contact information
Ermanno Brosch: Massey University
Gert Lube: Massey University
Matteo Cerminara: Istituto Nazionale di Geofisica e Vulcanologia–Sezione di Pisa
Tomaso Esposti-Ongaro: Istituto Nazionale di Geofisica e Vulcanologia–Sezione di Pisa
Eric C. P. Breard: University of Oregon
Josef Dufek: University of Oregon
Betty Sovilla: WSL Institute for Snow and Avalanche Research SLF
Luke Fullard: Massey University

Nature Communications, 2021, vol. 12, issue 1, 1-12

Abstract: Abstract Pyroclastic surges are lethal hazards from volcanoes that exhibit enormous destructiveness through dynamic pressures of 100–102 kPa inside flows capable of obliterating reinforced buildings. However, to date, there are no measurements inside these currents to quantify the dynamics of this important hazard process. Here we show, through large-scale experiments and the first field measurement of pressure inside pyroclastic surges, that dynamic pressure energy is mostly carried by large-scale coherent turbulent structures and gravity waves. These perpetuate as low-frequency high-pressure pulses downcurrent, form maxima in the flow energy spectra and drive a turbulent energy cascade. The pressure maxima exceed mean values, which are traditionally estimated for hazard assessments, manifold. The frequency of the most energetic coherent turbulent structures is bounded by a critical Strouhal number of ~0.3, allowing quantitative predictions. This explains the destructiveness of real-world flows through the development of c. 1–20 successive high-pressure pulses per minute. This discovery, which is also applicable to powder snow avalanches, necessitates a re-evaluation of hazard models that aim to forecast and mitigate volcanic hazard impacts globally.

Date: 2021
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/s41467-021-27517-9 Abstract (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:natcom:v:12:y:2021:i:1:d:10.1038_s41467-021-27517-9

Ordering information: This journal article can be ordered from
https://www.nature.com/ncomms/

DOI: 10.1038/s41467-021-27517-9

Access Statistics for this article

Nature Communications is currently edited by Nathalie Le Bot, Enda Bergin and Fiona Gillespie

More articles in Nature Communications from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().