During the period from 10 to 17 February 2016 the Karangetang appears visually still erupting with incandescent dome at night. The main crater emits a thin smoke white / blue, from a height of about 25-100 m. The lava accumulation in the ravines of the Batuawang and Kahetang is not stable, so that in case of heavy rain, it is likely to produce lahars. The dominant flow of lava happened in Batuawang focuses on distances of 2000 to 2500 m summit, it is necessary to monitor the accumulation of lava debris that are not stabilized and may slip into the ravine of Batuawang eventually covering the path. During the rainy season, people living along the banks of the Batuawang should be alert to the occurrence of lahars, because there are still many unstable material.
Seismicity during the period from 10 to 17 February 2016 showed earthquakes avalanche characteristic of the eruption of Karangetang , shallow volcanic earthquakes (VB) and phases of tremor. Many showed an increase, the number of shallow volcanic earthquakes (VB) is between 6 and 26 episodes per day. Earthquakes that indicate the cracking of rock (lava dome) increased. If we look at the energy of volcanic earthquakes during the period from February 10 to 17, 2016, there has been no significant improvement. Episodes of Tremor and Tremor spasmodic are still often recorded with the maximum amplitude ranges of 0.25 to 1 mm. The energy of the RSAM data increased on 8 September 2015, and had gradually decreased until November 6, 2015, climbing on 18 December 2015 and 27 December 2015. In January 2016, she had increased 2 times, also in February 2016 or energy RSAM increased influenced by an increase in shallow volcanic earthquakes (VB) until 16 February 2016.
Currently, the eruption of G. Karangetang is potentially effusive (lava flows) and present pyroclastic avalanches (incandescent lava). We must look at the explosive eruptions like the one that happened in September 2013, during which at the top has been formed an unstable lava dome, making it easily destructible. Pyroclastic avalanches can occur when the flow of lava that accumulates becomes unstable.
The results of the analysis of data and visual and instrumental evaluation until February 17, 2016 at 18:00 did not show a significant increase / decrease in volcanic activity, therefore it is concluded that the Karangetang remains at level of activity : level III (SIAGA).
The level of activity will be reduced / increased again if there is a decrease / increase in volcanic activity and will be adapted to the level of the threat.
February 20, 2016. Karangetang , Indonesia :
Source : VSI ( Translation from Indonesian: Google).
Photos : Iyan Mulyana (2007) .