On August 27th, 1883, at 10:02 a.m., a volcano on the island of Krakatoa in Indonesia erupted and generated the loudest noise ever recorded. Some details:
- It was so loud that the sound waves created by the eruption circled the earth five times! This is known because weather observers recorded changes in barometric pressure every 34 hours around the world for five days (thirty-four hours is the amount of time it takes for sound to travel around the planet).
- The eruption was heard over 3,000 miles away. That’s like a sound created In San Francisco being heard in NYC. It ruptured the ear-drums of of the crew of a ship 40 miles from the volcano.
- A factory 100 miles from the eruption registered the noise as 172 decibels. That is incredibly loud in its own right and downright amazing for being over 100 mikes away. For context, the threshold for pain is 130db and standing right next to a jet engine is 150db. Each 10db increase is a doubling of loudness. The top of the scale – from a physics perspective – is 194 decibels – higher than that and sound waves are so intense that a vacuum is created. The Krakatoa eruption likely was over the 194db threshold so it created vacuum. Wow.
So – it was really loud.
And as intense as the sound was, the tsunamis caused by the eruption were worse. According to How Stuff Works, “some of the waves reached Hawaii and even South America, on the other side of the Pacific. But the destruction mostly happened in the Indonesian archipelago itself. Waves as tall as 135 feet (41 meters) crashed into coastal cities, towns and villages on the islands of Java and Sumatra. In Batavia — now Jakarta – 2,000 Chinese immigrants who lived on low-lying areas around the harbor were drowned. The city of Serang reportedly was entirely submerged under the waves, with nearly its entire population killed.”