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Between 19 May and 21 October 1883, the volcanic island of Krakatoa (located in the Sunda Strait, then part of the Dutch East Indies—modern-day Indonesia) began erupting, lasting more than five months.

On 27 August, the island had its most significant eruption, which destroyed over 70% of the island and its surrounding archipelago, the island collapsing into a caldera. The eruption of 27 August had an estimated volcanic explosivity index of 6, and is one of the deadliest and most destructive volcanic events in recorded history; the third explosion of that day, that occurred at 10:02 a.m., remains the loudest-known sound in history. The explosion was heard 3,110 kilometres (1,930 mi) away in Perth, Western Australia, and Rodrigues near Mauritius, 4,800 kilometres (3,000 mi) away. The acoustic pressure wave circled the globe more than three times. At least 36,417 deaths are attributed to the eruption and the tsunamis it created. Significant additional effects were felt worldwide in the days and weeks after the volcano's eruption. Additional seismic activity was reported until February 1884, but any reports after October 1883 were dismissed by Rogier Verbeek's subsequent investigation into the eruption.

In the years before the 1883 eruption, seismic activity around the Krakatau volcano was intense, with earthquakes felt as far away as the Australian Northern Territory, one of which, in 1880, damaged a lighthouse. Eruptions of ash reached an estimated altitude of 6 kilometres (20,000 ft), and explosions could be heard in Batavia (Jakarta) 160 km (100 mi) away, rattling windows and doors. Around 16 June, there were loud explosions and a thick black cloud covered the islands for five days.

Due to the limitations of the speed of sound, it is likely that people on these far away islands did not hear Krakatau for nearly four hours after its eruption. The eruption is estimated to have reached 180 dBSPL (180 dB re 20 μPa, or 20 kPa), loud enough to be heard 5,000 kilometres (3,100 mi) away.

The tsunamis which accompanied the eruption were believed to have been caused by gigantic pyroclastic flows entering the sea; each of the four great explosions was accompanied by large pyroclastic flows resulting from the gravitational collapse of the eruption columns.

About 10% of the eruption fatalities were from pyroclastic flows. Around noon on 27 August 1883, a rain of hot ash fell around Ketimbang (now Kalianda in Lampung Province) in Sumatra, known as 'The Burning Ashes of Ketimbang', killing approximately 1,000 people in Sumatra.

In the aftermath of the eruption, it was found that Krakatoa had almost entirely disappeared, except for the southern third.

The record rainfall that hit Southern California during the water year from July 1883 to June 1884—Los Angeles received 970 millimetres (38.18 in) and San Diego 660 millimetres (25.97 in)—has been attributed to the Krakatoa eruption.

The 1883 Krakatoa eruption darkened the sky worldwide for years afterwards and produced spectacular sunsets worldwide for many months. British artist William Ascroft made thousands of colour sketches of the red sunsets halfway around the world from Krakatoa in the years after the eruption.

Although the violent phase of the 1883 eruption was over by the late afternoon of 27 August, after light returned by 29 August, reports continued for months that Krakatoa was still in eruption.

Most of the material deposited by the volcano is magmatic in origin, and the caldera formed by the eruption is not extensively filled with deposits from the 1883 eruption.

The reddish sky in the background is the artist's memory of the effects of the powerful volcanic eruption of Krakatoa, which deeply tinted sunset skies red in parts of the Western hemisphere for months during 1883 and 1884, about a decade before Munch painted The Scream. 2022 Hunga Tonga–Hunga Haʻapai eruption and tsunami – Similar-sized eruption in 2022

Quick Facts

• Although the violent phase of the 1883 eruption was over by the late afternoon of 27 August, after light returned by 29 August, reports continued for months that Krakatoa was still in eruption.
• Additional seismic activity was reported until February 1884, but any reports after October 1883 were dismissed by Rogier Verbeek's subsequent investigation into the eruption.
• On 27 August, the island had its most significant eruption, which destroyed over 70% of the island and its surrounding archipelago, the island collapsing into a caldera.
• The explosion was heard 3,110 kilometres (1,930 mi) away in Perth, Western Australia, and Rodrigues near Mauritius, 4,800 kilometres (3,000 mi) away.
• In the years before the 1883 eruption, seismic activity around the Krakatau volcano was intense, with earthquakes felt as far away as the Australian Northern Territory, one of which, in 1880, damaged a lighthouse.

Source material: Wikipedia - "1883 eruption of Krakatoa". Adapted and summarized for DiscoverScroll. Original contributors are credited through the linked Wikipedia article. Read original on Wikipedia. CC BY-SA 4.0. Changes were made from the original.