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Beirut explosion: TNT equivalence from the fireball evolution in the first 170 milliseconds

Aouad, C. J. and Chemissany, W. and Mazzali, P. and Temsah, Y. and Jahami, A. (2021) Beirut explosion: TNT equivalence from the fireball evolution in the first 170 milliseconds. Shock Waves, 31 (8). pp. 813-827. ISSN 0938-1287. doi:10.1007/s00193-021-01031-9.

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The evolution of the fireball resulting from the August 2020 Beirut explosion is traced using amateur videos taken during the first 400 ms after the detonation. Thirty-nine frames separated by 16.66–33.33 ms are extracted from six different videos located precisely on the map. Time evolution of the shock wave radius is traced by the fireball at consecutive time moments until about t≈170 ms and a distance d≈128 m. Pixel scales for the videos are calibrated by de-projecting the existing grain silos building, for which accurate as-built drawings are available, using the length, the width, and the height and by defining the line-of-sight incident angles. In the distance range d≈ 60–128 m from the explosion center, the evolution of the fireball follows the Sedov–Taylor model with spherical geometry and an almost instantaneous energy release. This model is used to derive the energy available to drive the shock front at early times. Additionally, a drag model is fitted to the fireball evolution until its stopping at a time t≈500 ms at a distance d≈145±5 m. Using the derived TNT equivalent yield, the scaled stopping distance reached by the fireball and the shock wave-fireball detachment epoch within which the fireball is used to measure the shock wave are in excellent agreement with other experimental data. A total TNT equivalence of 200±80t at a distance d≈130 m is found. Finally, the dimensions of the crater size taken from a hydrographic survey conducted 6 days after the explosion are scaled with the known correlation equations yielding a close range of results. A recent published article by Dewey (Shock Waves 31:95–99, 2021) shows that the Beirut explosion TNT equivalence is an increasing function of distance. The results of the current paper are quantitatively in excellent agreement with this finding. These results present an argument that the actual mass of ammonium nitrate that contributed to the detonation is much less than the quantity that was officially claimed available.

Item Type:Article
Related URLs:
URLURL TypeDescription
Aouad, C. J.0000-0001-6063-0344
Chemissany, W.0000-0002-9113-4463
Mazzali, P.0000-0001-6876-8284
Temsah, Y.0000-0001-8576-5544
Jahami, A.0000-0003-4851-1822
Additional Information:© The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit Received 07 October 2020; Revised 09 July 2021; Accepted 27 July 2021; Published 04 October 2021. The authors would like to thank the referees for their valuable comments which improved the content of the current study. Additionally, the authors express their thoughts to the victims of this tragic event and wishes for the recovery of the wounded. We express our thoughts for the city of Beirut, hoping a prompt and efficient reconstruction. We primarily thank the eyewitnesses who posted their videos on social media, for without them this article would not have been possible (ex: Elias Abdelnour). We are also thankful to Alexandra Elkhatib, Samuel Rigby, Jorge Diaz, Gerard-Philippe Zehil, Philip James, Toni el Massih, Nabil Abou Reyali, and Igor Chilingarian for useful discussions and Ranjesh Valavil and Abbas Chamseddine for their help. The authors declare that they have no conflict of interest. The authors wish to state that referencing a social media profile does not indicate endorsement of the political or other views of that user.
Subject Keywords:Explosion physics; Beirut explosion; Fireball; Shock wave; Blast; Ammonium nitrate explosion
Issue or Number:8
Record Number:CaltechAUTHORS:20211029-225144141
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Official Citation:Aouad, C.J., Chemissany, W., Mazzali, P. et al. Beirut explosion: TNT equivalence from the fireball evolution in the first 170 milliseconds. Shock Waves 31, 813–827 (2021).
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:111697
Deposited By: Tony Diaz
Deposited On:02 Nov 2021 21:26
Last Modified:08 Feb 2022 17:31

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