M 3.3 Explosion - 1 km ENE of Beirut, Lebanon

The Beirut, Lebanon explosion was processed using the same basic methods that we use for regional earthquakes. To remove uncertainties in the location associated with seismic methods, we fix the location to the location seen in videos of the blast. Standard methods were used to calculate the magnitude. The reported magnitude is not directly comparable to an earthquake of similar size because the explosion occurred at the surface where seismic waves are not as efficiently generated. News reports state the explosion was caused by 2750 tons of ammonium nitrate which is roughly equivalent to 1100 tons of TNT.