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Minggu, 02 Maret 2014

KRAKATOA VOLCANO


The history of Mount Krakatau dates back far beyond the cataclysmic eruption of 1883. An ancient Javanese text called Pustaka Raja Purwa or Books of Kings recorded a far more extreme episode in the year 338 Sakaor, or 416 AD at the site of what was believed to be the current Krakatau Islands. The event was also believed to have changed the shape of the land.
“A monstrous rumbling sound was heard from Mount Batuwara which was followed by dark clouds, lightning and endless thunders. Soon after, great storm and devastating rain plunged the entire planet into total darkness. A massive flood came from Mount Batuwara flowing east towards Mount Kamula…….As the waters drowned the area, Java became divided creating the island of Sumatra” 
Berend George Escher and several other geologists believe that the event mentioned in the text was the Ancient Mount Krakatau, which at the time was called Mount Batuwara. This Ancient Mount Krakatau was believed to have a height of 2000m above sea level with a diameter of approximately 11Km.

Ancient Mount Krakatau
The colossal eruption devastated three quarters of the Ancient Mountain and left a huge caldera at the Sunda Strait. The edges of the caldera sprung out of the sea and formed the small islands of Rakata, Sertung and Panjang. The eruption was said by many to have caused the pitch black century, which caused a drastic lowering of temperature and caused the Sampar Bubonic disease that drastically cut populations. Some even argue that the cataclysm brought an end to the ancient Persian Empire and Nazca civilization in South America.  The eruption of the Ancient Krakatau was estimated to have lasted 10 days with the speed of volcanic matters reaching up to 1 million tons per seconds. The eruption was also believed to have formed atmospheric layers as thick as 20-150 meters and cooling global temperature by 5-10 degrees for 10-20 years.
David Keys, Ken Wohletz, and others postulate that the violent volcanic eruption, possibly of Krakatoa, may have been responsible for the global climate changes that occurred in 535AD, instead of 416AD.
Rakata, which was one of the three remaining islands of the Ancient Mount Krakatau grew over the years as a result of the volcanic activity inside the earth and formed Mount Rakata (or some called it Krakatau). Subsequently, two other volcanoes emerged from the Caldera namely Mount Danan and Mount Perboewatan. The three volcanos eventually merged into what became Mount Krakatau.

The 1883 Krakatau Cataclysm   
Early in the morning of May 20, 1883, the captain of the German warship Elizabeth reported seeing an 11-km-high cloud of ash and dust rising above the uninhabited island of Krakatau. Over the ensuing two months, crews on commercial vessels and sightseers on charted ships would experience similar spectacles, all of which were associated with explosive noises and churning clouds of black to incandescent ash and pumice. From a distance, the largest of these natural fanfares impressed the local inhabitants on the coastal plains of Java and Sumatra, creating a near-festive environment. Little did they realize that these awe-inspiring displays were only a prelude to one of the largest eruptions recoded vividly in history.
On Sunday, August 26, at 12:53 p.m, Krakatau delivered the opening salvo to a climactic eruption that would last throughout the evening of August 27. The initial blast generated an ear-shattering fusillade accompanied by black churning cloud of volcanic debris that rose quickly to 25 km above the island. Over the next several hours, it would widen dramatically to the northeast, rising to a height of at least 36 km.
On the following day, Monday, August 27, the frightening display of volcanic power would culminate in a series of at least four stupendous eruptions that began at 5:30 a.m., climaxing in a colossal blast that literally blew Krakatau apart. The noise was heard over 4600 km away, throughout the Indian Ocean, from Rodriguez Island and Sri Lanka in the west, to Australia in the east. Two-thirds of the island collapsed beneath the sea into the underlying, partially vacated magma chamber. About 23 square kilometers of the island, including all of Perboewatan and Danan, subsided into a caldera about 6 km across. At an original height of 450 m, Danan had collapsed to depth of 250 m below sea level. The eruption is still recorded up to this day as the loudest sound ever heard in the world in modern history.
The combined effects of pyroclastic flows, volcanic ashes, and tsunamis had disastrous results in the region. The official death toll recorded by the Dutch authorities was 36,417 casualties, although some sources put the estimate at more than 120,000. There are numerous documented reports of groups of human skeletons floating across the Indian Ocean on rafts of volcanic pumice and washing up on the east coast of Africa, up to a year after the eruption.

Aftermath
The eruption again destroyed the mountain and left remnants in the small islands of Rakata, Sertung, and Panjang. In 1927, in the center of the sea caldera rose a new mountain that was later dubbed as Anak Krakatau or the child of Krakatau. The newly”born” mountain continues to grow at an average rate of five inches (13 cm) per week equates to an average growth of 6.8 metres per year. The island is still active, with its most recent eruptive episode having begun in 1994.

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