Ijen volcano (East Java) update: decreasing activity, crater is open again for visits
Thursday Feb 09, 2012 17:21 PM | BY: T
The crater of Ijen is again open for visitors. The Indonesian Geological Survey lowered the alert level for Ijen volcano yesterday back from 3 (where it had been since 18 Dec, on a scale of 1-4) to 2.
The decision was based on measurements of decreasing seismic, visual and temperature parameters that are regularly monitored at the volcano:
1) Decreasing steaming and bubbling from the lake was visually observed during the past weeks.
2) Decreasing seismic activity, from 304 harmonic tremor signals, 3 low frequency earthquakes, 74 shallow volcanic quakes, and 21 normal volcanic quakes recorded during 1-7 January to 21 harmonic tremor signals, 40 low frequency earthquakes, 102 shallow volcanic quakes, and 8 normal volcanic quakes.
3) Decreasing lake temperatures: surface temperatures were 23 deg C in January and are now back to 18-19 deg C. Below-surface lake water temperatures (measured at 5 m depth) have decreased from 42 deg C on 20 January to 37 deg C on 2 February.
Links / Sources:
Wednesday, Dec 28, 2011
Ijen volcano in East Java, famous for its turquoise crater lake and the massive sulfur deposits inside the crater, might be close to an eruption. ... [more]
Friday, Dec 16, 2011
The alert level of Ijen volcano in East Java has been raised to alert/unrest (2 out of 4) due to increased seismic activity and increased temperatures and fumaroles inside the crater, famous for its turquoise acid lake and the sulfur deposits, which are being quarried by workers. ... [more]