ERUPTION IN 1883
Before the eruption in 1883, Mount Krakatoa erupted in 1680 produces acid andesitic lava. Then in 1880, Mount Perbuwatan actively secretes though erupting lava. After that time, no volcanic activity at Krakatoa until May 20, 1883. Since this date, the seismic activity began to occur around the mountain is intense with a series of eruptions that are lighter, after 200 years of sleep. That early signs would be devastating eruption in the Sunda Strait. This intensity continues with a small eruption that peaked on 26-27 August 1883.
On the day Monday, August 27, 1883, at exactly 10:20, going on a series of four large explosions on the mountain that almost destroyed the entire island. According to Simon Winchester, a geologist graduated from Britain’s Oxford University and author of National Geographic said that the blast was the biggest, the loudest voice and the most devastating volcanic events in modern human history.
Earthquake kit list – The combined effects of pyroclastic flows, volcanic ash, and the tsunami disaster in the region produce effects throughout the world. The most famous Krakatau eruption culminated in a series of large explosions, which included one of the most violent volcanic events in history.
The eruption was so powerful, according to official records colonial Dutch East Indies, 165 villages and towns near Krakatau destroyed, and 132 damaged, and hot clouds and the resulting tsunami killed about 36,000 people (other sources mention 36,417 deaths), although some sources give estimates more than 120,000.
They came from 295 villages coastal areas ranging from Merak in Cilegon until Cilamaya in Karawang, West coast of Banten to Tanjung Layar in Ujung Kulon Panaitan Island and southern parts of Sumatra. There are many documented reports of groups of human skeletons floating in the Indian Ocean on a raft floating volcanic and swept the east coast of Africa up to a year after the eruption.
The sound of the eruption was heard 4,830 km (3,000 miles) away in Alice Springs Australia towards the east and the island of Rodrigues near Mauritius Africa, as far as 4,653 kilometers to the west. This explosion is regarded as the loudest sound ever heard in modern history, it can even be heard by 1/8 of the earth’s population at that time. The sound of the eruption was reported so hard that if there are people within a radius of ten miles (16 km), then they will become deaf.
With an estimated Volcanic explosivity index (VEI) reached 6 eruption was equivalent to the explosion of 200 megatons of TNT (840 PJ) – approximately 13,000 times the impact of a nuclear bomb Little Boy (13-16 kt) that destroyed Hiroshima and Nagasaki, Japan, during World War II, and four times the impact of the Tsar Bomba (50 Mt), the most powerful nuclear device ever detonated.
Krakatoa explosion resulting tsunami. Until before the tragedy of the tsunami in Aceh on 26 December 2004, this was the most powerful tsunami in the Indian Ocean region. In Ujungkulon, flood entrance to 15 km to the west.
The tsunami waves that caused even spilled over to the coast of Hawaii, Central America and the west coast of the Arabian Peninsula are 7000 kilometers away. Tsunami (ocean waves) rose as high as 40 meters of destroyed villages and whatever is on the coast. The tsunami was caused not only by the eruption but also submarine landslide.
The eruption of Krakatau generates a volcanic winter (reducing the temperature around the world with an average of 1.2 ° C for 5 years). This eruption caused global climate change. The next day until a few days later, residents of Jakarta and Lampung hinterland no longer see the sun. The world was dark for two and a half days due to volcanic ash that covered the atmosphere.
The sun shines dim until next year. Scattering of dust visible in the sky Norway to New York. Average global temperatures dropped as much as 1.2 degrees Celsius for up to one year after the eruption. The weather pattern will then be screwed over the years and the temperature does not return to normal until 1888.
Krakatoa explosion had been throwing stones pumice and volcanic ash with a volume of 18 cubic kilometers. Bursts of volcanic ash pushed up to an altitude of 80 km (50 miles). Hard objects which flew into the air it falls on the plains of the island of Java and Sumatra, even to Sri Lanka, India, Pakistan, Australia and New Zealand. A total of 20 million tons of sulfur released into the atmosphere. The eruption in 1883 spent about 25 km3 (6 square miles) of stone.
Impact of Physical Geography
The eruption destroyed Danan Mountains, Mount Perbuwatan and part of Mount Rakata where half cone lost, making the basin width of 7 km and a depth of 250 meters and destroying more than two-thirds of the island of Krakatoa.
The shock waves from explosions recorded on barographs around the world. Some barographs recorded wave seven times for five days. Four times in the form of waves away from the mountain to its antipodal point, and three times behind the wave back to the mountain. In other words, the wave has circled the earth three and a half rounds.
CHILDREN emergence Krakatau
In 1927, about 40 years after the eruption of Mount Krakatau emerged a new island is known as Anak Krakatau (English: Child of Krakatoa ) from the caldera formed in 1883 that is still active and still growing in height. High growth speed of about 0.5 meters (20 inches) per month. Every year it becomes higher at about 6 meters (20 feet) and a width of 12 meters (40 feet).
Another note said height is about 4 centimeters per year, and if counted, then within 25 years the addition of high-achieving children Rakata 190 meters (7,500 inches or 500 feet) higher than the previous 25 years. The cause of the high mountain was caused by the material out of the belly of the new mountain.
At this time the height of Anak Krakatau reach about 230 meters above sea level, while Mount Krakatau previous height of 813 meters above sea level. Periodic eruptions have continued, with the last eruption in 2009, 2010, 2011, and 2012. In late 2011, the island has a radius of about 2 kilometers (1.2 miles), and the high point of about 324 meters (1,063 feet) above the surface sea, or had grown to 5 meters (16 feet) each year.
Eruption Prediction in Future
According to Simon Winchester, despite what happened in the life of Krakatau once very scary realities of geology, seismic and tectonic in Java and Sumatra strange to be sure that what used to happen at some point will happen again. Nobody knows exactly when Anak Krakatau will erupt. Some geologists predict these eruptions will occur between 2015-2083. However, the effect of the earthquake in the Indian Ocean base at December 26, 2004 can not be overlooked.
According to Professor Ueda Nakayama one volcano expert Japanese national, Anak Krakatau is still active and relatively safe although there are often small eruptions, there are only certain times of the tourists are prohibited from approaching the area because of the danger of lava that spewed out of the volcano. Other experts claim there is no plausible theory of Anak Krakatau will re-erupt.
Even if there are at least 3 for another century or after 2325 AD But clearly, the number of casualties incurred more powerful than the previous eruptions. Anak Krakatau today by the general public is better known as “Krakatoa” also, though in fact is a new mountain that grew after the previous eruption.
Comparison eruption by Mount Other
According to researchers at the University of North Dakota, the explosion of Krakatoa (1883) and the explosion of Tambora (1815) recorded a value Volcanic explosivity index(VEI), the largest in modern history. The Guinness Book of Records recorded the explosion of Krakatoa as the most powerful explosion in recorded history.
The Krakatoa explosion in 1883 is still less than the eruption of Mount Toba and Tambora in Indonesia, Mount Tanpo in New Zealand, and Mount Katmal in Alaska. However, these mountains erupted deep in a time when the human population is still very small. Meanwhile, when Krakatoa erupted, the human population is quite dense, science and technology has evolved, submarine telegraph was invented, and the submarine cable has been installed.
Thus it can be said that the current information technology is growing and developing rapidly. Progress is, unfortunately, has not been matched by progress in the field of geology. The geologist was even able to give an explanation of these eruptions. Mount Krakatoa erupted, the tremors felt to Europe.