Credits to Tatahakai for the Original Calcs
Big boom, I'll work out the distance to the explosion through angsizing since it reaches all the way to the screen, since it covers far more distance than that it'll be a lowball but meh
2atan(tan(70/2)*(30/575)) = 0.0494314682 radians or 2.83221450300217 degrees
Average oak tree height = 18 meters distance to center of explosion = 369.89 meters
Air blast radius (near-total fatalities) Yield: Y = ((x/0.28)^3)/1000
X is in kilometers, Y is in Megatons iirc
((0.36989/0.28)^3)/1000 = 2.1 kilotons of TNT (Small Town Level)
2.1 kilotons of TNT = Small Town Level or Low 7-C
Credits to Zanybrainy2000
W = R^3*((27136*P + 8649)^(1/2)/13568 - 93/13568)^2
W stands for energy in tons of TNT, R stands for radius in meters, and P stands for pressure in bars.
Radius is 369.89 meters, and 20 PSI (1.37895146 bars) should be used if it did said heavy collateral damage.
369.89^3 *((27136*1.37895146 + 8649)^(1/2)/13568 - 93/13568)^2 = 4067.27882 Tons of TNT
Small Town level+