From Wired Science:
The long-distance scientific recordings of the blast wave from the first hydrogen bomb test have been rediscovered in a formerly classified safe at Columbia University.
On November 1, 1952, physicists created the second fusion explosion the solar system has ever known. The first occurred around 4.5 billion years ago and ignited the ongoing fusion reaction in the sun. The second, the Ivy Mike experiment, was shorter lived and detonated on an atoll in the South Pacific. This 10-megaton blast was five times more powerful than all the explosives used in World War II combined, including the nuclear-fission bombs dropped on Hiroshima and Nagasaki.