BEIRUT: Only a handful of cities have ever experienced a blast the size of which hit Beirut, according to professor Andrew Tyas. The explosion saw a shockwave rattle through the city shattering windows and destroying shops.
Lebanese President Michel Aoun cited 2750 tons of ammonium nitrate as the cause of the explosion.
Tyas and his team at University of Sheffield Blast Impact and Engineering Research group spent Wednesday morning examining the size of the fireball that rose from the blast in order to extrapolate the size of the explosion. The group’s early estimates suggest the intensity of the explosion is similar to that of 1,500 tons of TNT.
“The intensity of the shockwave is equivalent to 20 to 30 percent of the shockwave caused by Hiroshima,” Tyas told The Daily Star, adding: “it’s astonishing.”
Partially due to the lack of historical comparison, Tyas said the damage caused by the blast is hard to predict.
“There’s a luck element of how the blast is shielded or focused. I'd expect some windows 1.5-2 kilometers away to survive, but other windows 4 or more kilometers away to be damaged, depending on the urban layout,” he said, explaining why some buildings appeared less scathed than others.
Aside from broken glass, Tyas said the long impact on buildings in terms of short and long term damage was dependent on the quality of the buildings; Tyas expected that poorly maintained buildings would be at risk of long-term damage if they were within a kilometer of the port.
“I’d be surprised if there was serious damage beyond that,” Tyas said.
Nadine Bekdache the co-director and co-founder of Public Works Studio who analyze housing in Lebanon, believes that the blast's impact will be worsened by the state of Beirut’s housing. “There is no investment in safety and rehabilitation in Beirut’s old buildings.”
Bekdache said that in the neighborhoods of Karantina and Roum, two areas heavily affected by the blast, over half the buildings are old.
She was especially concerned about Karantina as its a low-income neighborhood and very close to the blast.
In the immediate aftermath of the blast many in Beirut worried that toxic gases would lead to an additional health emergency. Najat Saliba ,the head of the atmospheric and analytic lab at the American University of Beirut, told The Daily Star said that dangerous gases had been released into the air but were quickly dispersed.
“The long-term health impact is not so serious because there wasn’t long-term exposure,” she said.
The most tragic consequence of the explosion is the loss of human life and the injuries sustained. Health Minister Hamad Hassan said Wednesday afternoon that 115 people had died, dozens were missing and over 4,000 had been injured. With hospitals overwhelmed and cases still rising, it remains to be seen how many were injured in the blast.
Tyas said the main cause of injuries in explosions in urban settings is broken glass. When The Daily Star contacted Beirut Municipality, it was told that the Lebanese Army was still collecting data on the scale of shattered glass. People have reported glass breaking in Beirut’s suburbs, many kilometers from the blast.