On the morning of August 27, 1883, a series of enormous explosions destroyed most of Krakatoa, a volcanic island in the Sunda Strait between Java and Sumatra. The region was then the Dutch East Indies and is now Indonesia.
The final blasts were heard thousands of kilometers away. Tsunamis tore along the nearby coasts. Ash and gas spread through the upper atmosphere and tinted sunsets around the world for months afterward. Thanks to the undersea telegraph, it was also one of the first natural disasters to be reported around the world almost as it happened.
Before the big day
Krakatoa had been quiet for about two hundred years when it started erupting again in May 1883. Ships passing through the Sunda Strait reported ash and explosions, and the activity carried on through the summer. For a while, local people and visitors treated it as something to watch. Some even hired a boat to get a closer look.
On August 26, the eruption grew much stronger. All through that afternoon and into the night, a run of explosions threw ash high into the air.
The climax
On the morning of August 27 came four huge explosions. The third, at about 10:02 a.m. local time, was the biggest.
That sound was heard on Rodrigues Island in the Indian Ocean, near Mauritius, roughly 4,800 kilometers away. A police chief there reported hearing something like the distant roar of heavy guns. People in parts of Australia reported hearing it too. It is often called the loudest sound in recorded history. That claim is hard to prove, but it gives a fair sense of how far the noise traveled.
Barometers around the world recorded the pressure wave from the explosion. Scientists later worked out that the wave had circled the planet several times, turning up on instruments again and again over the days that followed.
The tsunamis
The eruption itself caused relatively few of the deaths. Most came from the tsunamis. Waves estimated at up to 30 meters or more in places hit the coasts of Java and Sumatra, and whole towns and villages were swept away.
Dutch authorities gave an official death toll of 36,417. Some historians believe the real number may have been higher, because records for small coastal villages were incomplete.
What happened to the island
About two-thirds of Krakatoa vanished. Much of it collapsed into the emptied magma chamber beneath, leaving a large caldera under the sea.
In 1927, a new volcanic island rose out of the sea inside the caldera. It was named Anak Krakatau, meaning "Child of Krakatoa," and it has been active ever since. In December 2018, part of Anak Krakatau slid into the sea during an eruption and set off a tsunami that killed more than 400 people along the coasts of Java and Sumatra. Krakatoa is still a dangerous place.
The world's sunsets
The eruption pushed ash and sulfur gases up into the stratosphere. Over the months that followed, people all over the world reported unusually vivid red and orange sunsets and strange colors in the sky.
In some places the glow was so intense that fire brigades were called out, because people assumed something was on fire. According to newspaper reports from the time, that happened in New York and in Poughkeepsie, New York, in late 1883.
Some art historians have suggested that the red sky in Edvard Munch's painting The Scream (1893) may reflect his memory of Krakatoa sunsets in Norway. The idea has been published, and it has also been disputed. Munch himself described a blood-red sky seen on a walk, and others have proposed a different explanation involving a type of cloud seen in Norway. The theory is interesting, but it remains a theory.
Global temperatures fell somewhat the following year, which is consistent with the cooling effect that sulfate aerosols from large eruptions are known to have.
A global news event
By 1883, telegraph cables already connected Java to the rest of the world. News of the eruption reached newspapers in Europe and North America within roughly a day.
In his book Krakatoa: The Day the World Exploded, the author Simon Winchester argues that this made it one of the first global media events. Readers in London and New York were learning about a disaster in the East Indies at nearly the same time as it was unfolding.
The Royal Society report
In 1888, the Royal Society in London published a long report on the eruption. It brought together observations from around the world, including barometer readings, reports of the sound, accounts of the sea waves and descriptions of the unusual sunsets. It is an early example of international scientific collaboration focused on a single natural event, and it is still a valuable source.
Krakatoa or Krakatau?
In English the island is often spelled Krakatoa, especially in older sources. The Indonesian spelling is Krakatau. Both names refer to the same place.
The well-known 1969 film Krakatoa, East of Java got the geography wrong. Krakatoa lies west of Java.
What the record supports
- The date and time of the main explosions are well documented by instruments and by witnesses.
- The sound reports from Rodrigues and elsewhere are documented in the Royal Society report.
- The death toll of 36,417 is the official figure. The true number may be higher.
- The link to *The Scream* is a hypothesis and has not been established as fact.
- The fire brigades called out for the sunset glow are documented in newspaper reports.
Why it still matters
Krakatoa helped scientists understand how volcanic eruptions can affect the atmosphere and climate across the globe. It also showed that for a volcano near the sea, the deadliest effect can be the tsunamis rather than the lava or ash. Both lessons still apply. Indonesia sits on the Pacific Ring of Fire and has more active volcanoes than almost any other country.
Sources
- G. J. Symons, editor, The Eruption of Krakatoa and Subsequent Phenomena, Report of the Krakatoa Committee of the Royal Society (London, 1888).
- Simon Winchester, Krakatoa: The Day the World Exploded, August 27, 1883 (HarperCollins, 2003).
- Smithsonian Institution, Global Volcanism Program, "Krakatau."
- U.S. Geological Survey, materials on volcanic aerosols and climate.
- Indonesian National Board for Disaster Management (BNPB), reports on the December 2018 Anak Krakatau tsunami.