Which height is too short in Indonesia

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Indonesia - volcanoes in the "Ring of Fire"

The Indonesian archipelago consists of 17,508 islands and extends over an area of ​​1875 x 5000 kilometers. With 225 million inhabitants spread over around 6000 islands, Indonesia is the fourth largest nation in the world. A humid, subtropical climate and fertile, volcanic soils allow up to 4 harvests per year and thus ensure the supply of the many people.

Indonesia is not only densely populated, it is also hit by a particularly large number of volcanic eruptions, earthquakes and tsunamis. The accumulation of these natural phenomena, which often turn into natural disasters in the densely populated country, is due to the special, tectonic location of the archipelago. Indonesia is a volcanic island arc that extends along the continental interface between the Pacific plate on the one hand and the continental plates of India-Australia and Eurasia on the other. Thus, the volcanoes of Indonesia are part of the circumpacific fire belt, the "Ring of Fire".

In the southern part of the Indonesian archipelago, the Indo-Australian plate slides under the Eurasian continental plate and is partially melted in the process. Highly viscous magma rises behind this subduction zone and in this way forms the volcanoes of the Sunda Arc. To the east of the Sunda shelf, which is connected to the Asian mainland, is the Sahul shelf, which is part of the Australian continental plate. The largest number of active volcanoes in the world can be found at the borders of this complex system of continental interfaces. How many volcanoes are actually classified as active varies depending on the author of the information. There will be around 150 volcanoes. At the same time, earthquakes and tsunamis often occur here.

In addition to the most recent earthquake and tsunami disasters, which most people remember well, there were 3 volcanic disasters in Indonesia that are hard to beat in terms of drama. A good 72,000 years ago, the Toba super volcano erupted on Sumatra and caused a volcanic winter, as a result of which almost all of humanity died out. In 1815 the Tambora erupted on Sumbawa and 1816 became known as the year without a summer. In 1883 Krakatau exploded in the Sunda Strait between Sumatra and Java. More than 36,400 people died in pyroclastic currents and tsunamis.

In Indonesia, however, smaller eruptions occur almost every day, which are of interest due to their special aesthetics. Recently the volcanoes Karangetang (Siau Island), Ibu and Dukono (Halmahera), Rinjani (Lombock) and Anak Krakatau (Sumatra) made a name for themselves.

Images from Indonesia


Volcanoes in Sumatra

Sumatra is not only the westernmost of the large Indonesian islands, but also the one with the largest volcano in the archipelago. This is the aforementioned Toba. Further north is the Sinabung, whose eruptions began in 2010. 10 years later he was still sporadically active. Here pyroclastic currents destroyed several villages.
Sumatra has other volcanic superlatives to offer, such as the highest mountain on the island is a volcano. That is the Kerinci, which at least brings it to an altitude of 3805 m. It is located on the west coast of the island, not far from the active Marapi, which is often confused with the Merapi on Java. There are several volcanoes along the west coast that owe their existence to subduction at the Sunda Arc. This also includes Krakatau. It is located in the Sunda Strait, a strait between Sumatra and Java. The volcanic island has had several spectacular eruptions. This includes not only the disaster of 1883, but also the birth of Anak Krakatau. Much of this young volcanic island collapsed in December 2018.

Volcanoes on Java

Java is the main island of the Indonesian archipelago and extremely volcanically active. Galunggung dominates the north of the island. It is notorious for its explosive eruptions, which often hit a VEI 4 or 5. The last eruption phase occurred in 1982. On June 24th, it almost came to a catastrophe when a Boeing 747 of the airline British Airways got caught in a cloud of ash. All four engines failed and the aircraft sank from 11,300 to 4,100 meters in 16 minutes. After the gliding flight, the engines started again and you could make an emergency landing in Jakarta.
The most famous volcanoes in Central Java are Merapi, Semeru and Bromo, both of which are associated with the Tenegger Caldera. Due to their predominantly acidic chemistry, the lava in these subduction zone volcanoes is very viscous and gas-rich, and they tend to form huge, explosive eruptions.

The Merapi, which is within sight of the metropolis of Yogjakarta. In 1996, 66 people died in the foothills of Kaliurang village when they were caught in a pyroclastic flow. In 2006, two workers died in the neighboring village of Kaliadem. They also fell victim to a pyroclastic current.

The flat cinder cone of the Bromo volcano rises in the east of Java. Together with three other volcanoes (Mount Kursi, Mount Widodaren and Mount Batok) it is located in the Tengger Caldera; this collapse crater has a diameter of 8.5 x 10 kilometers and is 110 meters deep.

Bromo is the youngest crater cone in the caldera. It got its name after the Hindu god Brahma. Every year, thousands of believers gather at the crater rim to make sacrifices on the occasion of the Kasada festival. A long staircase leads to the rim of the crater; from there you can see a steaming conveyor vent.

A good 60 eruptive phases have been recorded since 1767. Most of the Bromo eruptions are Strombolian; occasionally they also have a volcanic character. In June 2004, two people died in a surprise outbreak. The last outbreak so far took place in 2007.

The 3676 m high Semeru is not only Java's only permanently active volcano, but also the highest mountain on the island. It is within sight of the Tenger Caldera and together with it forms the Tenger Semeru Massif. An exploration and ascent requires at least a three-day tour with appropriate logistics and a good level of fitness, because the nocturnal ascent to the crater is exhausting and only something for experienced volcano hikers. While the ash eruptions occurring several times an hour can normally be observed without any danger, unexpectedly violent eruptions occur again and again, which then pose a serious danger to the observer on the crater plateau. It was not until 2000 that a group of volcanologists was killed in one of these violent eruptions. In 2009 the activity fell sharply and is at a rather low level.

The volcanoes of Java not only bring horror to the country, but also ensure fertile soils and provide valuable raw materials. Sulfur is mined at Kawah Ijen (East Java). Inside the crater there is an abundant fumarole field and the hot vapors are conducted in a pipe system to the bank of the acid lake, where the sulfur then condenses from the gases. The sulfur is extracted by hand and loaded into two baskets, which are carried up the steep crater walls by the workers on a pole over their shoulders. Hard, dangerous and unhealthy work, but one that brings money and enables the workers to live in - comparatively - secure conditions.

In addition to the active volcanoes, there are also numerous volcanoes in the inter-volcanic stage on Java. The phenomena here range from boiling springs and mud pools to meter-high mud bubbles that burst with a thud. Many of these geothermal phenomena can be found on the Dieng Plateau.

Bali and the volcanoes

Bali is the most popular holiday island in Indonesia and home to numerous deities who are worshiped by the predominantly Hindu population. Bali is not only popular with Australians, but also with Germans and Austrians. But since autumn 2017 the gods seem to be angry: the Gunung Agung awoke. First there was a seismic crisis that caused an almost panic-like state. The eruption began in November, which so far (as of February 2018) has remained much smaller than feared. In January 2018, the neighboring Batur showed the first signs of a possible awakening: some earthquakes and volcanic tremors were registered.

Lombok and Rinjani

The island of Lombok is located west of Bali and is dominated by the 3726 m high Rinjani volcano. This volcano is a stratovolcano with a large caldera in the summit area. The Barujari volcanic cone is located in the caldera. The Rinjani, more precisely Mount Barujari, erupted 4 times in this millennium.
Lombok was often in the headlines in the summer of 2018, as a series of strong earthquakes destroyed large areas of the island's infrastructure. Landslides occurred at the volcano, which destroyed the hiking trails.

Sumbawa and Pulau Sangeang

The infamous Tambora Volcano is located on Sumbawa Island. This was devastated when the Tambora erupted in 1815. The following year went down in the chronicles of world history as "The year without a summer". It was then that the legendary kingdom of Tambora fell. Today the island has recovered from the disaster. The volcanic island of Pulau Sangeang lies off the northeast coast of Sumbawa. The coasts of the almost circular island are dominated by the volcanic cones Doro Api and Doro Mantoi. The two cones are the peaks of the Sangeang Api complex volcano. The active part is taken over by Doro Mantoi. This erupts in the long term strombolian. Vulcanian or even Plinian eruptions occur at longer intervals.

First published in 2006, last update in 2020

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Anak Krakatau: Location 06.10 S, 105.42 E, height approx. 400 m, stratovolcano

Kawah Ijen: Location 06/08 S, 114.24?, Altitude 2386 m, stratovolcano

Karangetang: Location 2.78 ° N, 125.40 ° E, altitude 1784 m, stratovolcano

Merapi: Location 07.54 S, 110.44 E, altitude 2911 m, stratovolcano

Rinjani Location 8.42 ° S, 116.47 ° E; Height 3726 m, complex volcano

Sinabung: Location 3.17 ° N, 98.392 ° E, altitude 2460 m, stratovolcano

Semeru: Location 08.11 S, 112.92 E, altitude 3676 m, stratovolcano

Tambora: 08.25 S, 118.00 E, altitude 2850 m, stratovolcano

Toba: Location 2.58 ° N, 98.83 ° E, altitude 2157 m, caldera volcano

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