Krakatau Islands Nature Reserve

Krakatau Islands Nature Reserve

volcano I Dunia Kita Bersama I   10:25 PM

Source: http://www.indonesia.travel/

In the afternoon of 26^th August 1883 Mt. Krakatau suddenly erupted with such cataclysmic force that its boom could be heard in Burma to far away Australia. The next day, massive volcanic materials blasted so high causing a gaping gash in its crater and the mountain imploded and sank. The boiling sea brought about huge tsunami waves of more than 10 meters high, devastating the towns of Banten and Anyer on Java and Lampung on Sumatra, wiping out their entire population.  The tsunami waves spread throughout the Indian Ocean, and was said to be felt even as far away as France. While Krakatau’s volcanic ash was reported to circle the earth’s atmosphere, creating spectacular sunsets around the globe for two years.      

Today, where once stood the mighty Krakatau volcano, a number of idyllic small tropical islands are left in the Sunda Straits between the island of Java and Sumatra. These are the Krakatau islands which consist of Rakata or Krakatau Besar (Large Krakatau), Panjang or Krakatau Kecil (Small Krakatau),Sertung and the Anak Krakatau (The child of Krakatau). While the islands of Rakata, Sertung and Panjang are remnants of the ancient Mount Krakatau, Anak Krakatau is an active volcano that surfaced only in 1927 and incredibly, still continues to grow as a result of volcanic activities below.

Administratively, the Krakatau Islands are located within the sub-district of Rajabasa, South Lampung, in Lampung Province on Sumatra.  But, in fact they form part of the Ujung Kulon – Krakatau Nattional Park, which is recognized by UNESCO as World Heritage site.

As the site of one of the most catastrophic natural disasters in the world, the Krakatau Islands are considered today as a massive natural laboratory. Encompassing a total area of 13.735,10 hectares, they comprise 11.200 hectares of marine reserves and 2.535,10 hectares of land reserves, the Krakatau Islands bear considerable importance to scientists in Geology, Biology and volcanology. For general visitors, nonetheless, the sheer view and incredible history of volcanic activities of the islands are surely something worth travelling for. Information on accessibility can be found on how to get there. Terms and procedures on entering the nature reserve are available at tips.

 

Setting foot on an active volcano is certainly a one of a kind sensation, and if fortunate enough, visitors can watch as the Anak Krakatau volcano presents its active side. “Born” in 1927, the young volcano still frequently ejects smoke, lava and other volcanic materials as it continues to grow higher. The marine environment around the island offers its own attraction as it holds no less than 50 species of fish that live among its unspoilt coral reefs. Read more on the dramatic history of Mount Krakatau under Related Attractions:  History of Krakatau.          

The island- group along with its marine environment was declared by the Dutch Colonial government as a nature Reserve since 1919, encompassing a total area of 2.405,10 hectares. The Krakatau Islands were later in 1984 incorporated into the Ujung Kulon National Park located on the western part of Java. In 1990, the Directorate General for Forest Protection and Nature Conservation of the Ministry of Forestry assigned the management of the Krakatau Islands Nature Reserve to the Balai Konservasi Sumber Daya Alam or the Natural Resources Conservation Office of Lampung, on Sumatra, with the aim to protect and preserve its integrity as an important conservation site for science and education. In the same year the nature reserve was expanded by the Ministry of Forestry to cover the total area as known today.

In 1991, UNESCO acknowledged both Ujung Kulon National Park and the Krakatau Islands Nature Reserve as an integrated UNESCO Natural World Heritage site.  

Krakatau is also commonly known in the English-speaking world as Krakatoa. This may have been attributed to a sub-editor at “The Times” who may have typographically swapped the 'a' and 'o' of the Portuguese spelling as he interpreted a telegraphic report on the massive eruption of 1883. Furthermore, the 1969 Academy Award nominated movie, “Krakatoa, East of java” ,-which is geographically misleading, - also aided in popularizing the Krakatoa misspelling .The Smithsonian Institution's Global Volcanism Program cites the Indonesian name, Krakatau, as the correct name but says that its spelling as Krakatoa is also often used.

For more information about visiting Krakatau Island Nature Reserve,please contact:

BALAI KSDA LAMPUNG

Jl. Z. A. Pagar Alam IB - Bandar Lampung

Telp/Fax. (0721) 703882

Email: bksdalpg@yahoo.com and bksdalpg@gmail.com

Website: http://www.krakatau.or.id/

Krakatoa Volcano: Facts About 1883 Eruption

Krakatoa Volcano: Facts About 1883 Eruption

volcano I Dunia Kita Bersama I   10:24 PM

Mary Bagley, LiveScience Contributor

The eruption of Krakatoa in August 1883 was one of the most deadly volcanic eruptions of modern history. It is estimated that more than 36,000 people died. Many died as a result of thermal injury from the blasts and many more were victims of the tsunamis that followed the collapse of the volcano into the caldera below sea level.

The island of Krakatau (Krakatoa) is in the Sunda Strait between Java and Sumatra. It is part of the Indonesian Island Arc. Volcanic activity is due to subduction of the Indo-Australian tectonic plate as it moves northward towards mainland Asia. The island is about 3 miles wide and 5.5 miles long (9 by 5 kilometers).  Before the historic eruption, it had three linked volcanic peaks: Perboewatan, the northernmost and most active; Danan in the middle; and the largest, Rakata, forming the southern end of the island. Krakatau and the two nearby islands, Lang and Verlatan, are remnants of a previous large eruption that left an undersea caldera between them.

In May 1883, the captain of the Elizabeth, a German warship, reported seeing clouds of ash above Krakatau. He estimated them to be more than 6 miles (9.6 km) high. For the next two months, commercial vessels and chartered sightseeing boats frequented the strait and reported thundering noises and incandescent clouds. People on nearby islands held festivals celebrating the natural fireworks that lit the night sky. Celebration would come to a tragic halt on Aug. 27.

At 12:53 p.m. on Sunday the 26th, the initial blast of the eruption sent a cloud of gas and debris an estimated 15 miles (24 km) into the air above Perboewatan. It is thought that debris from the earlier eruptive activity must have plugged the neck of the cone, allowing pressure to build in the magma chamber. On the morning of the 27th, four tremendous explosions, heard as far away as Perth, Australia, some 2,800 miles (4,500 km) distant, plunged both Perboewatan and Danan into the caldera below the sea.

The initial explosion ruptured the magma chamber and allowed sea water to contact the hot lava. The result is known as a phreatomagmatic event. The water flash-boiled, creating a cushion of superheated steam that carried the pyroclastic flows up to 25 miles (40 km) at speeds in excess of 62 mph (100 kph). The eruption has been assigned a rating of 6 on the Volcanic Explosion Index and is estimated to have had the explosive force of 200 megatons of TNT. (For purposes of comparison, the bomb that devastated Hiroshima had a force of 20 kilotons. The Mount St. Helens explosion of 1980 had a VEI of 5.)

Tephra and hot volcanic gases overcame many of the victims in western Java and Sumatra, but thousands more were killed by the devastating tsunami. The wall of water, nearly 120 feet tall, was created by the volcanoes’ collapse into the sea. It completely overwhelmed small nearby islands. Inhabitants of the coastal towns on Java and Sumatra fled toward higher ground, fighting their neighbors for toeholds on the cliffs.  The steamship Berouw was carried nearly a mile inland on Sumatra; all 28 crewmembers were killed. Another ship, the Loudon, had been anchored nearby. The ship's captain Lindemann succeeded in turning its bow to face the wave and the ship was able to ride over the crest. Looking back, the crew and passengers saw that nothing was left of the pretty town where they had been anchored.

The explosions hurled an estimated 11 cubic miles (45 cubic km) of debris into the atmosphere darkening skies up to 275 miles (442 km) from the volcano. In the immediate vicinity, the dawn did not return for three days. Barographs around the globe documented that the shock waves in the atmosphere circled the planet at least seven times. Within 13 days, a layer of sulfur dioxide and other gases began to filter the amount of sunlight able to reach Earth. The atmospheric effects made for spectacular sunsets all over Europe and the United States. Average global temperatures were up to 1.2 degrees cooler for the next five years.

Mount Tambora & the year without a summer

While justifiably rated as one of the most destructive volcanic eruptions of modern times, Krakatoa was not the largest eruption in the recent history of Indonesia. That “honor” belongs to the eruption of Mount Tambora on April 10, 1815.

Tambora is the only eruption in modern history to rate a VEI of 7. Global temperatures were an average of five degrees cooler because of this eruption; even in the United States, 1816 was known as the “year without a summer.” Crops failed worldwide, and in Europe and the United States an unexpected outcome was the invention of the bicycle as horses became too expensive to feed.

The Child of Krakatoa

In 1927, some fishermen were startled as a column of steam and debris began spewing from the collapsed caldera. Krakatoa had awakened after 44 years of calm. Within weeks, the rim of a new cone appeared above sea level. Within a year, it grew into a small island, which was named Anak Krakatoa, or Child of Krakatoa. Anak Krakatoa has continued to erupt periodically, although mildly.

Child of Krakatoa, deadlier than its mother

Describe the 1883 eruption of Krakatau.

Describe the 1883 eruption of Krakatau.

volcano I Dunia Kita Bersama I   10:19 PM

The deadlier volcano than its mother

Krakatau erupted in 1883, in one of the largest eruptions in recent time. Krakatau is an island volcano along the Indonesian arc, between the much larger islands of Sumatra and Java (each of which has many volcanoes also along the arc).

There is a very fine book about the Krakatau eruption by Tom Simkin and Richard Fiske (Simkin, T., and Fiske, R.S., Krakatau 1883: The volcanic eruption and its effects: Smithsonian Institution Press: Washington, D.C., 464 p.), so if you really want to know about the eruption you should go to the nearest bookstore or library to find that.

Here are some highlights from their summary of effects:

1. The explosions were heard on Rodriguez Island, 4653 km distant across the Indian Ocean, and over 1/13th of the earth’s surface.
2. Ash fell on Singapore 840 km to the north, Cocos (Keeling) Island 1155 km to the SW, and ships as far as 6076 km west-northwest. Darkness covered the Sunda Straits from 11 a.m. on the 27th until dawn the next day.
3. Giant waves reached heights of 40 m above sea level, devastating everything in their path and hurling ashore coral blocks weighing as much as 600 tons.
4. At least 36,417 people were killed, most by the giant sea waves, and 165 coastal villages were destroyed.
5. When the eruption ended only 1/3 of Krakatau, formerly 5×9 km, remained above sea level, and new islands of steaming pumice and ash lay to the north where the sea had been 36 m deep.
6. Every recording barograph in the world documented the passage of the atmospheric pressure wave, some as many as 7 times as the wave bounced back and forth between the eruption site and its antipodes for 5 days after the explosion.
7. Tide gauges also recorded the sea wave’s passage far from Krakatau. The wave “reached Aden in 12 hours, a distance of 3800 nautical miles, usually traversed by a good steamer in 12 days”.
8. Blue and green suns were observed as fine ash and aerosol, erupted perhaps 50 km into the stratosphere, circled the equator in 13 days.
9. Three months after the eruption these products had spread to higher latitudes causing such vivid red sunset afterglow that fire engines were called out in New York, Poughkeepsie, and New Haven to quench the apparent conflagration. Unusual sunsets continued for 3 years.
10. Rafts of floating pumice-locally thick enough to support men, trees, and no doubt other biological passengers-crossed the Indian Ocean in 10 months. Others reached Melanesia, and were still afloat two years after the eruption.
11. The volcanic dust veil that created such spectacular atmospheric effects also acted as a solar radiation filter, lowering global temperatures as much as 1.2 degree C in the year after the eruption. Temperatures did not return to normal until 1888. The book is full of many more amazing bits of information. Hopefully these small excerpts will be useful to you.

Krakatau is still active. The presently-active vent has formed a small island in the middle of the ocean-filled caldera that developed during the famous big eruption of 1883. The island is called Anak Krakatau, which means child-of-Krakatau. It is pretty much erupting all the time at a low level, but once or twice a year it has slightly larger eruptions that people notice and sometimes report in the news. Of course none of these are anywhere near the size of the famous 1883 eruption.
Krakatau is following a pattern that is pretty common for volcanoes. This pattern involves hundreds to thousands of years of small eruptions to build up the volcano followed by 1 or more huge eruptions that causes the volcano to collapse into a caldera, and then the cycle starts over again.
The chances of a huge 1883-style eruption are very small for the time being.   However, it is certainly dangerous to go onto Anak Krakatau, especially if it is one of its more agitated moods. It is probably not even very smart to spend too much time on the small islands that form the remnants of what was once the main Krakatau island. This is because even a small collapse of Anak Krakatau could generate a small tsunami that could sweep towards these islands. Since they are so close to Anak Krakatau there wouldn’t be very much time for a warning.

Anak Krakatau photograph courtesy of and copyrighted by Robert Decker.

Visiting Krakatoa volcano in Sumatra, Indonesia

Visiting Krakatoa volcano in Sumatra, Indonesia

volcano I Dunia Kita Bersama I   10:16 PM

The son Of  Krakatau

Krakatau, a small island group in the Sunda Strait between the islands of Sumatra and Java is one of the world's most famous volcanoes. It is a mostly submerged caldera with 3 outer islands belonging to the rim and a new cone, Anak Krakatau, that has been forming a new island since 1927 and remains highly active.
Krakatau exploded spectacularly in a devastating Plinian eruption 1883 that killed more than 30,000 people (mostly by the huge tsunamis triggered by the eruption). The eruption was one of the first global news events after telegraph lines had connected the different continents.

Background:

The renowned volcano Krakatau (or Krakatoa) lies in the Sunda Strait between Java and Sumatra. Collapse of the ancestral Krakatau edifice, perhaps in 416 AD, formed a 7-km-wide caldera. Remnants of this ancestral volcano are preserved in Verlaten and Lang Islands; subsequently Rakata, Danan and Perbuwatan volcanoes were formed, coalescing to create the pre-1883 Krakatau Island. Caldera collapse during the catastrophic 1883 eruption destroyed Danan and Perbuwatan volcanoes, and left only a remnant of Rakata volcano. This eruption, the 2nd largest in Indonesia during historical time, caused more than 36,000 fatalities, most as a result of devastating tsunamis that swept the adjacent coastlines of Sumatra and Java. Pyroclastic surges traveled 40 km across the Sunda Strait and reached the Sumatra coast. After a quiescence of less than a half century, the post-collapse cone of Anak Krakatau (Child of Krakatau) was constructed within the 1883 caldera at a point between the former cones of Danan and Perbuwatan. Anak Krakatau has been the site of frequent eruptions since 1927.

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Source: GVP, Smithsonian Institution