50 Fun Facts About Krakatoa

Krakatoa lies in a strait between which two Indonesian islands?

The Sunda Strait sits at a sharp bend in the Indonesian island arc, possibly over unusually weak crust.

In which year did Krakatoa's catastrophic eruption take place?

The climactic explosions came on 26-27 August.

What volcanic explosivity index (VEI) is assigned to the 1883 eruption?

That is equivalent to about 200 megatons of TNT, four times the yield of the Tsar Bomba.

The 1883 explosion was roughly how many times more powerful than the Hiroshima bomb?

It ejected approximately 25 cubic kilometres of rock.

The explosion was heard about 4,800 km away on which Indian Ocean island near Mauritius?

Listeners there took it for cannon fire from a nearby ship.

What is the official death toll from the 1883 eruption?

Most victims were killed by the tsunamis rather than the eruption itself.

The 1883 eruption destroyed roughly what fraction of Krakatoa island?

Only the southern part, the Rakata cone, survived, sheared off into a 250-metre cliff.

What is the meaning of the name of the new island that emerged from the caldera in 1927?

Anak Krakatau grew about five metres a year until its 2018 collapse.

The child volcano's collapse in December 2018 caused a tsunami that killed how many people?

The volcano lost more than two-thirds of its volume and shrank from 338 m to just 110 m.

The earliest known mention of Krakatoa's name appears in which Old Sundanese text?

It calls it 'the island of Rakata, a mountain in the middle of the sea'.

The most likely origin of the name Krakatau is a Sanskrit word meaning what?

The Old Javanese rakaṭa also means crab, matching the earliest recorded forms of the name.

A discounted legend says a local replied 'Kaga tau' to a ship's captain, meaning what?

The story resembles similar linguistic myths about the words kangaroo and Yucatán.

Indonesia has more active volcanoes than any other nation. Roughly how many?

Most lie along Java and Sumatra, above the subducting Indo-Australian Plate.

Before 1883, which was the tallest of Krakatoa's three volcanic cones?

Rakata stood 820 m; Danan 450 m; Perboewatan just 120 m.

The Javanese Book of Kings records a cataclysmic eruption of 'mountain Kapi' in which year?

The account is considered unreliable, and drilling has ruled out a 535 eruption once blamed for global cooling.

A Dutch mining engineer saw Krakatoa 'completely burnt and barren' after which year's eruption?

Johann Wilhelm Vogel had seen it green and healthy just two years earlier.

Crews of which two ships stopped at Krakatoa in 1780 on their way home after Captain Cook's death?

They found a freshwater spring and a hot spring and described the inhabitants as friendly.

Which Dutch scientist surveyed Krakatoa in July 1880 and later led the investigation into the eruption?

He was allowed only a few hours on the island, but his samples proved vital afterwards.

When researchers first returned in May 1884, what was the only living thing they found?

Grass shoots were already growing by Verbeek's visit that October.

Which animal is Johann Handl, who quarried stone on the island from 1916, believed to have introduced?

He held a 30-year lease on the eastern half of the island but left after four years.

Krakatoa is part of which UNESCO World Heritage national park, inscribed in 1991?

The land on nearby Banten depopulated by the eruption reverted to jungle and became the park.

The 1883 eruption sequence began in which month?

Strombolian activity started on 20 May and continued for more than five months.

How many enormous explosions occurred on 27 August 1883?

The third, at about 10:02 a.m., was the biggest.

The third explosion of 27 August holds what record?

It was heard 3,110 km away in Perth and measured about 180 decibels at 160 km.

How many times did the pressure wave circle the globe?

Barographs recorded it seven times over five days.

The blast ruptured the eardrums of sailors on which ship, about 64 km away?

It also sent a gasometer pressure gauge in Batavia, 160 km away, off the scale.

The town of Merak was destroyed by a tsunami of roughly what height?

Waves reached 42 metres on the west coast of Java and 24 metres in southern Sumatra.

Which ship, anchored near Telok Betong, famously rode over the crest of the tsunami and survived?

Its passengers watched the wave sweep the town away entirely.

How many of the 3,000 people on the nearby island of Sebesi survived?

The island, 12 km away, was the nearest settlement to Krakatoa.

Roughly what share of the eruption's fatalities were caused by pyroclastic flows rather than tsunamis?

The flows crossed 40 km of sea to scorch victims on southern Sumatra.

A rain of hot ash that killed about 1,000 people in Sumatra is known as the Burning Ashes of which place?

The town is now called Kalianda, in Lampung Province.

For up to a year afterwards, rafts of what washed up on Africa's east coast bearing human skeletons?

Huge fields of floating pumice were reported for months.

By how much did average Northern Hemisphere summer temperatures fall the year after the eruption?

Sulfur dioxide in the stratosphere raised cloud reflectivity until it fell as acid rain.

Which 1893 painting has been proposed to show the sky over Norway as coloured by Krakatoa's ash?

Edvard Munch's red sky was linked to the eruption by an astronomer in 2004.

Krakatoa's red sunsets brought out fire engines in New York, Poughkeepsie and which other city?

British artist William Ascroft made thousands of colour sketches of the red skies.

Weather watchers tracking the ash cloud's 'equatorial smoke' made the first identification of what?

For years the moon also appeared blue and sometimes green through the ash.

What colour did the moon famously appear for several years after the eruption?

Ash particles about 1 micrometre wide scattered red light while letting other colours through.

Which atmospheric phenomenon was recorded for the first time in the eruption's aftermath?

People also saw lavender suns and a Bishop's Ring around the sun by day.

The eruption's massive shift of mass moved Earth's figure axis by roughly how much?

The Sunda Strait basin also deepened from 100 m to 200-300 m.

Which 1947 children's novel imagines Krakatoa as a diamond-rich island with a utopian society?

The eruption is a key plot device in William Pène du Bois's Newbery winner.

Which writer's 2003 book is subtitled 'The Day the World Exploded: August 27, 1883'?

He argues an 18th-century Dutch etching depicts the little-known 1680 eruption.

Ash from the 1883 eruption was propelled to an estimated height of how many kilometres?

Ash fell as far as 2,500 km away.

On what date did the child volcano permanently rise above sea level?

Earlier appearances in 1927-29 were washed away by waves within days or months.

How much rain fell on Los Angeles in the record 1883-84 wet season attributed to Krakatoa?

Many scientists doubt the link, since no El Niño was present.

Krakatoa was called 'The Fire Mountain' during which Javanese dynasty?

Eruptions have been tentatively dated to 850, 950, 1050, 1150, 1320 and 1530.

Material shot out of the volcano in the final lateral blast at roughly what speed?

Verbeek believed the final major eruption was a pyroclastic surge.

In which Indonesian province does the Krakatoa archipelago lie?

Lampung is at the southern tip of Sumatra.

Roughly how fast was Anak Krakatau growing in height each year, as measured in 2011?

It topped 400 metres by 2017 before the December 2018 collapse cut it back to 110 metres.

From which of Krakatoa's three cones did steam venting begin regularly in May 1883?

It was the northernmost cone; the earliest ash columns reached an estimated six kilometres.

Pre-eruption earthquakes around Krakatoa were felt as far away as which part of Australia?

One 1880 quake was strong enough to damage a lighthouse.