Each of the two atomic bomb blasts were thought to have been approximately equivalent to a blast produced from 20,000 tons of TNT (The Manhattan Engineer District, 1946).
Figures 4 and 5 are photos depicting the “mushroom clouds” that formed as the bombs were dropped on Hiroshima and Nagasaki respectively.
(To see recovered video footage of the Hiroshima bombing, click on the following link: Hiroshima bombing)
According to the Atomic Bomb Museum (2006), there were three main forms of energy released as a result of the nuclear bombs dropped over Hiroshima and Nagasaki:
1. Fireball (heat)
2. Shock wave and air blast (accounted for 50% of energy)
Figure 6 is a graphical representation of the energy released from the bomb explosions.
Directly beneath where the bomb was dropped on the ground (hypocenter) it has been estimated that the temperature reached approximately 7000 degrees F (Atomic Bomb Museum, 2006).
The explosions created areas of extremely high pressure which resulted in winds in excess of 980 mph at the hypocenters. The pressures created were approximately 8,600 pounds per square feet. From the hypocenters out to approximately 1/3 of a mile, most substantial concrete buildings were obliterated. Even a mile from the hypocenter, all brick buildings were destroyed as the wind velocity in these areas reached 190 mph and pressure was approximately 1,180 pounds per square feet (Atomic Bomb Museum, 2006).
Alpha, beta, gamma, and neutron rays were generated by the nuclear bombs, with the
gamma and neutron rays doing the most immediate damage and causing most early raditation deaths.
From 1/16 mile out in all directions from the hypocenter, most people died within a few hours.
Those located 1/2 mile from the hypocenter died within 30 days (Atomic Bomb Museum, 2006).