Krakatoa

Krakatoa (Indonesian: Krakatau) is a volcanic island made of a'a lava^[2] in the Sunda Strait between the islands of Java and Sumatra in Indonesia. The name is used for the island group, the main island (also called Rakata), and the volcano as a whole. The island exploded in 1883, killing approximately 40,000 people, although some estimates put the death toll much higher. The explosion is considered to be the loudest sound ever heard in modern history, with reports of it being heard nearly 3,000 miles (4,800 km) from its point of origin. The shock wave from the explosion was recorded on barographs around the globe.

HISTORY
The best known eruption of Krakatoa culminated in a series of massive explosions on August 26–27, 1883, which was among the most violent volcanic events in modern and recorded history.
With a Volcanic Explosivity Index (VEI) of 6,^[3] the eruption was equivalent to 200 megatons of TNT (840 PJ) – about 13,000 times the nuclear yield of the Little Boy bomb (13 to 16 kt) that devastated Hiroshima, Japan, during World War II and four times the yield of the Tsar Bomba (50 Mt), the largest nuclear device ever detonated.
The 1883 eruption ejected approximately 21 km³ (5.0 cu mi) of rock, ash, and pumice.^[4]
The cataclysmic explosion was distinctly heard as far away as Perth in Western Australia, about 1,930 miles (3,110 km) away, and the island of Rodrigues near Mauritius, about 3,000 miles (5,000 km) away.^[5]
Near Krakatoa, according to official records, 165 villages and towns were destroyed and 132 seriously damaged, at least 21,007 (official toll) people died, and many thousands were injured by the eruption, mostly from the tsunamis that followed the explosion. The eruption destroyed two-thirds of the island of Krakatoa.
Eruptions at the volcano since 1927 have built a new island in the same location, named Anak Krakatau (which is Indonesian for "Child of Krakatoa"). This island currently has a radius of roughly 2 kilometres (1.2 mi) and a high point around 300 metres (980 ft) above sea level, growing 5 metres (16 ft) each year.

Etymology and orthography

Although there are earlier descriptions of an island in the Sunda Strait with a "pointed mountain," the earliest mention of Krakatoa by name in the Western world was on a 1611 map by Lucas Janszoon Waghenaer, who labeled the island "Pulo Carcata." (Pulo is a form of pulau, the Indonesian word for "island"). About two dozen variants have been found, including Crackatouw, Cracatoa, and Krakatao (in an older Portuguese-based spelling). The first known appearance of the spelling Krakatau was by Wouter Schouten, who passed by "the high tree-covered island of Krakatau" in October 1658.^{[citation needed]}
The origin of the Indonesian name Krakatau is uncertain. The main theories are:

• Onomatopoeia, imitating the noise made by cockatoos (Kakatoes) which used to inhabit the island. However, Van den Berg points out that these birds are found only in the "eastern part of the archipelago" (meaning the Lesser Sundas, east of Java). (See Wallace Line).
• From Sanskrit karka or karkata or karkataka, meaning "lobster" or "crab. (Rakata also means "crab" in the older Javan language.) This is considered the most likely origin.
• The closest Malay word is kelakatu, meaning "white-winged ant. Furneaux points out that in pre-1883 maps, Krakatoa does somewhat resemble an ant seen from above, with Lang and Verlaten lying to the sides like wings.
• Van den Berg (1884) recites a story that Krakatau was the result of a linguistic error. According to the legend, a visiting ship's captain asked a local inhabitant the island's name, and the latter replied, "Kaga tau" (Aku nggak tau)—a Jakartan/Betawinese slang phrase meaning "I don't know. This story is largely discounted; it closely resembles other linguistic myths about the origin of the word kangaroo and the name of the Yucatán Peninsula.

The Smithsonian Institution's Global Volcanism Program cites the Indonesian name, Krakatau, as the correct name but says that Krakatoa is often employed.^[6] This has been attributed to a sub-editor at The Times (who may have typographically swapped the 'a' and 'o' of the Portuguese spelling) interpreting telegraphic reporting on the massive eruption of 1883.^[7] Also, like Egypt a couple of decades earlier, Polynesia (South Pacific) was in vogue in the late 19th century, and the Polynesian-like suffix -oa (as in Samoa) may have caught on as a result.^{[citation needed]} While Krakatoa is more common in the English-speaking world, the Indonesian Krakatau tends to be favored by others, including geologists. Rogier Verbeek seems to have started the modern convention of using Krakatau for the island proper and reserving Rakata for the main cone.

Etymology and orthography

Indonesia has over 130 active volcanoes,^[8] the most of any nation. They make up the axis of the Indonesian island arc system, which was produced by northeastward subduction of the Indo-Australian Plate. A majority of these volcanoes lie along Indonesia's two largest islands, Java and Sumatra. These two islands are separated by the Sunda Straits, which are located at a bend in the axis of the island arc. Krakatoa is directly above the subduction zone of the Eurasian Plate and the Indo-Australian Plate where the plate boundaries make a sharp change of direction, possibly resulting in an unusually weak crust in the region.
Before the 1883 eruption, Krakatoa comprised three main islands: Lang ("long," now called Rakata Kecil, or Panjang), and Verlaten ("forsaken" or "deserted," now Sertung), which were edge remnants of a previous very large caldera-forming eruption; and Krakatoa itself, an island 9 km (5.6 mi) long by 5 km (3.1 mi) wide. Also there was a tree-covered islet near Lang named Poolsche Hoed ("Polish Hat," apparently because it looked like one from the sea) and several small rocks or banks between Krakatoa and Verlaten. There were three volcanic cones on Krakatoa: Rakata, (820 m/2,690 ft) to the south; Danan, (450 m/1,480 ft) to the north; and Perboewatan, (120 m/390 ft) to the north (Danan may have been a twin volcano)