Ijen Volcano - John Seach



East Java, Indonesia

8.05 S, 114.24 E,
summit elevation 2386 m

Ijen volcano contains the world's largest acidic volcanic lake. It is located in east Java, Indonesia.

The Ijen volcanic complex consists of several stratovolcanoes and cinder cones and a 20 km wide caldera. Ijen caldera is the largest in Java. The size of the crater is about 960 m x 600 m. The primary dangers at Ijen are pyroclastic flows, lahars, and lava flows.

Ijen volcano photos by John Seach

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Ijen volcano 2012

kawah ijen
Kawah Ijen 2012

Miners dig sulphur from the active vents at Ijen. Liquid red sulphur erupts from the vents and cools to a yellow colour

Kawah Ijen 2012

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Ijen volcano

ijen sulphur mining
Ijen sulphur miner

Ijen sulphur miner, 2012

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Kawah Ijen. (pH less than 2)

Thermal springs are located on Ijen lakeshore. The lakeshore fumarole discharges (170-245°C) have both a magmatic and a hydrothermal component. 

Post Caldera Eruptions
Post-caldera activity consist of phreatomagmatic, phreatic, strombolian and plinian eruptions from 22 separate vents. Current volcanic activity is located at Kawah Ijen which has a depth of 200-300 m. Most eruptions at the volcano have been phreatic.

2011 Activity
Between 8-13 December 2011 harmonic tremor and 77 shallow volcanic earthquakes were recorded at the volcano. Seismicity began to increase in October 2011 and continued high levels of shallow volcanic earthquakes have continued at the volcano into December. Between 1-13 December visual observations showed brown-white emissions with a weak pressure rising 50-200 m above the crater. On 15th December 2011 the alert status at Ijen volcano was raised to level 2 (out of a maximum 4). A 1 km exclusion zone was placed around the crater. This affected both visitors and sulphur miners.

2004 Activity
An increase in activity at Kawah Ijen resulted in the area being closed to visitors in June 2004. The lake changed colour from green to white, sulphurous rocks and foam were emitted.

2002 Eruptions
A small explosion occurred at Ijen volcano on 29th July 2002. Ash emissions continued until mid August.

2000 Eruptions
Sulphur emissions entered the cabin of a Singapore to Denpasar flight on 15th July 2000. Ijen volcano was suspected as the source of the emissions. Gray was emissions occurred from the volcano in mid August.

1999 Eruptions
Two phreatic explosions occurred on 28th June 1999. The eruptions were heard 2 km from the lake.

1994 Eruptions
On 3rd February 1994, a small phreatic eruption occurred at the southern end of the crater lake.

1993 Eruptions
Three phreatic eruptions occurred at Ijen volcano on 3-4 July 1993. Eruption were preceded by a change in lake colour from whitish-green to brown. On 5th July rockfalls were observed at the inner crater south wall. Another phreatic eruption occurred on 7th July, with rumbling noises heard at the sulphur weighing station 750 m from the lake. Two phreatic eruptions occurred on 1st August and were heard at the weighing station.

1936 Eruption
Upwelling eruptions began at Kawah Ijen on 7th November 1936. Between 7-14 November the eruptions occurred west of the deepest part of the lake at a depth of 170 m. On 15th November, eruptions occurred 200 m ESE at a depth of 198 m. During the larger eruptions, waves swept over the weir on the western side of the lake. Eruptions stopped on 17th November.

1817 Eruption
The eruption of Ijen in 1817 lasted 33 days. The crater lake was ejected. Large areas around the volcano were inundated, especially the plain of Rogodiambi. Several villages were destroyed, and many people and animals killed.

Ijen Volcano Eruptions

2002, 2000, 1999, 1994, 1993, 1952, 1936, 1917, 1817, 1796.
640 BC ± 50 yr (most recent magmatic eruption).