It was obvious to everyone who witnessed it that the Aug. 4 explosion in Beirut was a devastating one, killing at least 200 people and injuring thousands. Now, a team from the UK's Sheffield University is detailing just how powerful the blast was, per the BBC: They say it was one of the largest non-nuclear detonations ever. In their assessment of the explosion, published last month in the journal Shock Waves, engineers estimated the yield to be between 500 tons and 1,100 tons of TNT—making the explosion about 1/20th of the size of the atomic bomb dropped on Hiroshima, Japan, in 1945. That type of blast would release enough energy to power more than 100 residences for a year, a release notes.
The scientists conducted their analysis by viewing multiple videos of the explosion that circulated online, following how the blast's shock waves rippled through the city. "Think of it like a kid on a swing," Dr. Sam Rigby, one of the study's co-authors, tells the BBC. "If you push the child and see how far they go, you can then work out how hard the push was. That's essentially how we work out the yield." The engineers hope their research will help planners prep for future emergencies. "When we know what the yield is from these sorts of events, we can then work out the loading that comes from that," Rigby says, calling the explosion a "devastating" one. "And that tells us how to construct buildings that are more resilient." (Read more explosion stories.)