Atoms make a sound

The loudest sound to date was shock waves like 100,000 atomic bombs

On August 27, 1883, the earth emitted the loudest noise ever recorded: the source of the earth-shaking crash was the Indonesian island of Krakatau in the Sunda Strait between Java and Sumatra, which exploded in a huge volcanic eruption. The roar of this eruption could be heard clearly and distinctly even thousands of kilometers away, like the physicist Aatish Bhatia reported on "Nautilus".

It is now known that the shock waves from the eruption circled the earth at least four to seven times before subsiding. Calculations also showed that the explosion of the volcano corresponded to the explosive force of up to 2,000 megatons of TNT - which is equivalent to 100,000 Hiroshima bombs. This comparatively harmless volcanic explosion, which tourists captured on video off Papua New Guinea, gives a certain idea of ​​how this can be imagined:

Residents of Western Australia and Papua New Guinea at a distance of 3,200 kilometers, for example, described "a series of loud bangs reminiscent of artillery fire from the northwest". While still on the island of Rodrigues in the southwest of the Indian Ocean, almost 5,000 kilometers away from the outbreak, ear witnesses reported a clearly audible roar. 160 kilometers from Krakatau, the volume of the eruption was still 172 decibels - this corresponds to the noise level of a rocket taking off in the immediate vicinity and is well above the pain threshold of 130 decibels.

"Everyone believed that the last days of the earth had come"

The eruption, which continued to have effects around the globe several months later, sent 20 cubic kilometers of lava and rock into the sky at almost twice the speed of sound. When the up to 800 meter high formation from the volcanoes Rakata, Danan and Perbuwatan flew into the air, masses of water streamed into the emptied magma chambers. A tsunami up to 40 meters high is the result. Hot ash rain falls another 400 kilometers. More than 150 villages on the coasts of the islands of Sumatra and Java are destroyed, 40,000 people die.

The first officer of the US three-master "WHBesse" experienced the spectacle on his ship less than 100 kilometers northeast of the island: "It was midnight at noon, with the gust a heavy ash shower set in, the air was so stuffy that you could hardly breathe could ", he noted in the logbook. "Terrible roar from the volcano, the sky full of flashes of light ... the howl of the wind that drove through the rigging was one of the most gruesome experiences one can imagine ... everyone believed that the last days of the earth had come. " (tberg, red, April 21, 2018)