Before the tsunami that killed hundreds, Krakatoa’s massive eruption in 1883 rocked the world
- The force of the explosions during the 1883 eruption was reportedly 10,000 times stronger than the atomic bomb dropped on Hiroshima
- The eruption sent a plume of ash 27km into the air, affecting weather patterns across the globe for years, and plunging the surrounding area into darkness for days
The eruption of Anak Krakatoa that triggered a deadly tsunami on Saturday has a historic precedent in the eruption of the larger Krakatoa volcano in 1883.
At least 429 have died and 1,300 have been injured as a result of Saturday’s tsunami, which has displaced thousands from coastal communities in Java and Sumatra.
On August 27, 1883, the tiny volcanic island Krakatoa in the Sunda Strait between Java and Sumatra blew itself into the history books, altering weather patterns around the world for years, killing an estimated 37,000 people, and inspiring the creation of an enduring work of art.
Indonesia remains one of the most tectonically active areas on Earth and is currently home to 127 active volcanoes. Much of the archipelago itself was formed by the shifting of three immense continental plates, causing islands to emerge out of the ocean floor.
Anak Krakatoa, “child of Krakatoa” rose in 1928 from the caldera blasted into the ocean during the eruption of its namesake. It has been erupting sporadically since, rising to its current height of about 300 metres above sea level as a result of lava flows.
Anak Krakatoa, also known as Krakatau, has been observed for eruptions for the past decade and has been especially active in the past six months.
Ongoing eruptions late last week included a violent burst on Saturday that is thought to have caused part of the volcano to collapse into the surrounding sea – as well as possible underwater landslides – triggering the tsunami.
Scientists have warned for years of a possible event like Saturday’s tsunami but Indonesia’s primary warning system is designed to detect earthquakes, rather than displacements as a result of volcanic activity.
In 2012, scientists at the Geological Society of London studying volcano-induced tsunamis warned of such an event.
“Owing to the high population, the concentration of road and industrial infrastructure along some parts of the exposed coasts of Java and Sumatra, and the low elevation of much of this land, the tsunami might present a significant risk,” the scientists wrote. “The example of Krakatau Volcano illustrates the point that tsunamis generated by volcanic eruptions and flank instability are a neglected hazard.”
Bigger than Hiroshima
Eruptions over the course of several days in August 1883 included four enormous explosions on August 27, each of which triggered a tsunami in the surrounding area, devastating more than 150 coastal villages and resulting in an estimated 37,000 deaths.
The force of the explosions during the 1883 eruption was reportedly 10,000 times stronger than the atomic bomb dropped on Hiroshima during the second world war, heaving huge coral blocks weighing hundreds of tons to the shore, and launching enough ash into the atmosphere to lower global temperatures by more than 1 degree Celsius for the following year.
The eruption sent a plume of ash 27km into the air, affecting weather patterns across the globe for years, and plunging the surrounding area into darkness for days. As the ash circled the globe, blue and green sunsets were observed around the world for the next three years. Months later, gigantic chunks of pumice and ash encasing trees and other debris washed ashore as far as Mauritius and Australia.
The world learned of the eruption within 24 hours with the help of a telegraph from Jakarta. It was the first natural disaster to be reported internationally at such speed.
“I was passenger on board a steamer going down the western side of the Strait of Malacca at the southern end, on the morning of the 27th of August last, and was called up by the captain to observe the unusual appearance of the sky, which was as brilliantly lit up as if by the electric light,” wrote a sailor to the editor of the Manchester Guardian in 1883.
“Coupled with this was a noise as if a very heavy bombardment was going on – a noise which led us to suppose that the Dutch were having a fight. As daylight came we lost the flashes of light, but had still the noise.”
The shock wave felt around the world
The explosions were reportedly heard in Australia and across the Indian Ocean in Mauritius. The sound was so powerful it burst the eardrums of British sailors floating 70km away from the eruption site.
“The Krakatoa explosion registered 172 decibels at 100 miles from the source. This is so astonishingly loud, that it’s inching up against the limits of what we mean by sound,” science writer Aatish Bhatia wrote in a blog post. “Amazingly, for as many as five days after the explosion, weather stations in 50 cities around the globe observed this unprecedented spike in pressure re-occurring like clockwork, approximately every 34 hours. That is roughly how long it takes sound to travel around the entire planet.”
The resulting shock wave was detected by every recording barograph in the world at the time, including instruments in Paris and Washington DC.
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Krakatoa’s eruption even inspired one of the 19th century’s most famous works of art, Edvard Munch’s painting The Scream. Researchers from Texas State University in 2004 located the spot where Edvard Munch had been standing when he watched the spectacular sunset in far-off Oslo in November 1883. Munch reportedly “felt a great, unending scream piercing through nature,” while watching the sunset, inspiring the painting 10 years after Krakatoa’s eruption half a world away.
Today, officials warn the continued eruption of Anak Krakatoa puts the area at risk for recurring tsunamis.
“The potential for a fresh tsunami is still possible, and the volcanic eruption of Anak Krakatau continues to occur, potentially triggering tsunami,” Indonesia’s National Disaster Management Agency said.