|a vulcano /active|
|History of eruption;|
|The eruptions recorded in history are as follows:|
1796: It is the first recorded eruption, and is considered a phreatic eruption.
1817: January 16 Residents around Banyuwangi hear a terrible rumbling sound like a cannon boom, accompanied by an earthquake. On January 15, a mud flood to Banyuwangi (Junghuhn, 1853, p.1022), while Taverne (1926, p 102) suspected the probability of the 1817 eruption, most of the lake water was flowed by the ‘Banyupait’ river.
1917: Taverne (1926, p. 102) Writes that the lake’s water was boiling with mud and steam sometimes erupting in the crater lake, the mud was thrown up to 8-10 m above the water level. The same thing happened again on 7 – 14 March. Neuman Van Padang (1951, p 158), considers it an eruption on a crater lake, and a phreatic eruption on February 25 and March 13.
1936: Neuman van Padang (1936, p.10 and 1951, p.158), considers November 5-25 a phreatic eruption and an eruption on the crater lake, producing lava as in 1796 and 1817. Human victims are absent.
1952: On April 22 at 6.30, a smoke eruption was as high as 1 km and an audible noise came from Sempol. Inside the crater a mud eruption as high as 7 m, almost the same as the 1936 eruption incident. The victim does not exist. (Hadikusumo, 1950 – 1957, p.184).
1962: On 13 April, in the middle of the surface of Crater Lake Ijen gas bubbling occurs in two places, each about 10 m in diameter. and on April 18 at 07:42 there was a boast of water in the northern part of the crater lake about 6 m in diameter, then the boast was enlarged to 15-20 m. At 12:15 hours boast water is spewing water as high as about 10 m. Water color of the original lake green turned into a whitish green.
1976: October 30th, 09.44 o’clock was seen boasting water at two places near Silenong for 30 minutes.
1991: 15, 21 and 22 March, there was a water boasting diameter of about 5 m with a change of crater water color from light green to brown. According to the sulfur miners there is a burst of gas as high as 25 – 50 m with high speed. This hoax is deformed by a seismograph in the form of a continuous remastered earthquake of 16 – 25 March 1991.
1993: Date 3 hours 08.45 phreatic eruption in the middle of the lake accompanied by strong pressure and loud sounds with 75 m high bursts, Water color from whitish green turns brownish and the surface of the lake becomes dark. On July 4, 08.35, a phreatic eruption was marked by spraying water about 35 m high. On July 7 at 2:15 pm there was a phreatic eruption accompanied by a loud enough sound and was heard as far as 1 km. On August 1 at 16:35, there was a phreatic eruption accompanied by two explosive sounds that sounded up to 1 km. This eruption was preceded by an earthquake felt around the top. Thick white clumps of smoke with strong pressure are seen reaching a height of about 500 m.
1999: From 28 June to 28 July there was an increase in activity in the crater lake which was marked by a rise in the temperature of the crater lake water reaching 46’C (July 3) and at the same time the solfatara temperature 1, 4 and 5 respectively 198’C, 176 ‘and 168’C. On July 8, there was a decrease of crater lake water temperature at the same location to 40’C while the solfatara temperature increased respectively to 210’, 221 ‘and 207’C
2000: On June 6, 2000 there was an increase in activity marked by an increase in the temperature of Crater Lake Ijen up to 55’C and phreatic eruption. From the seismic data recorded an increase in the number of earthquakes, volcanic earthquakes and tremors also occur which later increased in late July. High smoke above the crater which was originally 25 m, at the end of mid-September rose to 50 m above the crater. A week later the activity decreased, among others, marked by the height of the smoke that returned to 25 m and the crater lake water dropped to less than 40’C.
2001: January 8, the increase of volcanic activity is indicated by the boiling water of the lake like boiling, the smell of solfatara gas is very sharp, there is a loud blaser and thick white smoke with strong pressure (direction of perpendicular smoke) and at the location of sulfur mining there is a fire sulfur, according to the solfatara employee there has been an eruption in the water of the crater lake the possibility of phreatic eruption. On January 14, the surface temperature of the crater lake in Dam reaches 48’C.
2004: Increased increase in volcanic activity. lake water temperature reach 51’C, fumarola temperature reach 240’C. pH 0.4. From the seismic data recorded an increase in the number of volcanic earthquakes and recorded also a continuous tremor earthquake. This increased activity was not followed by an eruption.
2005: In August a strong intensity of solfatara breaks accompanied by sulfur sublimation at the bottom edge of the south-southeast crater.
|Elevation (meters above sea level);|
|2.443 m (8.015 ft)|
|Type of eruption;|
|The eruption that ever happened was phreatic and magmatic. Phreatic eruption is more common because of volcano Ijen crater, so the existence of direct or indirect contact between water with magma to form a high-pressure steam that causes the eruption.|
From the history of its activities, since 1991 phreatic eruption occurs every one to 3 years. While the year 1917 to 1991 eruption period recorded 6 to 16 years. The great eruption that claimed human sacrifice was in 1817.
|Topology & Geology;|
|Mount Ijen is located at the eastern tip of Java Island from the Bali Strait to the Bondowoso area covering an area of 500 km2, consisting of volcanic deposits such as volcano ash, lapili, volcano bomb and leleran lava. The eruption that destroyed the peak of volcano in the Ijen mountains is Mount Raung and Mount Ijen.|
Ijen volcano is divided into three morphological units Reksowirogo (1971), namely;
1. Highland Ijen; The high land of Ijen consists of mountaintops, plains and hills. Inside this area there is a volcano that is still active or already extinguished (no more volcanic activities). The active volcanoes include Ijen Crater and Mount Raung, while the volcanoes include Mount Blau, Pawenan, Papak, Widodaren, Lempuyangan, Rante, Lebu agung, Kukusan, Delaman, Pedot, Cilik, Pendil, Jampit, Genteng, Anyar, Lingker, Melaten and Merapi.
Plains on high ground; The boundaries of the plains are north of Mount Pendil, Blawan, Blau and Mount Rante in the northwest. This plain consists mostly of Blawan coffee plantations, Jampit and Kali Sat.
The hills of Tanah Tinggi; Consists of high peaks and upstream of the river. The high peak of almost all the parasitic volcanoes that occur after the formation of Ijen caldera which includes Ijen Crater, Mount Ranti, Pawenan, Merapi, Ringgih, Widodaren, Kukusan and Papak. The rivers are directly on the edge of Ijen crater is the river Banyupait and Bendo.2. The area around the Slope; It is an erosion area located north of the mountain between 1550 m to 150 m, east from 800 m to 100 m and south from 1400 m to 300 m.3. Plain area; Is a deposition area consisting of paddy fields, settlements, moor, plantations, cities and rivers.Mount Ijen eruption releases gas, pyroclastic material consisting of sand, ash and volcanic bombs all of which are stone-like. Ijen volcanic rock types according to Brouwer (in Kemmerling, 1921) consist of andesit augit hipersten.
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