Visually, the G. Awu is usually shrouded in fog, with, as is evident, the inability to observe from the observation post of the volcano, solfataras and the emissions of G. Awu.
The results of monitoring of the seismicity of G. Awu during the period of April 2016 shows that the seismicity has fluctuated, with a tendency to increase in the number of earthquakes that began to be clearly observed significantly on May 11, 2016. The number of local earthquakes and deep volcanic tectonic earthquakes recorded their highest number ever recorded in the last one year period. The number of registered shallow volcanic earthquakes is the second highest ever recorded in the last period of one year after the incident of November 24, 2015, when the level of activities had been increased from level I (normal ) to level II (Alert).
The results of calculation of seismic amplitude (RSAM) indicates that the short-term growth model of G. Awu, observed on May 11 has dropped. But the long-term trend shows that seismic activity of the G. Awu has increased . The results of the estimate of the epicenters of G. Awu show that the center of seismic activity is mainly scattered at depths of 500 to 4000m.
The increase of deep volcanic seismic activity and shallow of the G. Awu indicates an increase in the magmatic liquid supply to the surface.
Based on the analysis of visual, instrumental record, and the potential threat of danger, since May 12, 2016 at 12:00 the level of activity of G.Awu was increased from Level II (waspada) to Level III (SIAGA).
Intensive monitoring is ongoing to assess the level of activity and the threat of eruption of the G. Awu. If there is a significant change in volcanic activity, the activity level of Awu can be reviewed and modified depending on the threat level.
The massive Gunung Awu stratovolcano occupies the northern end of Great Sangihe Island, the largest of the Sangihe arc. Deep valleys that form passageways for lahars dissect the flanks of the volcano, which was constructed within a 4.5-km-wide caldera. Powerful explosive eruptions in 1711, 1812, 1856, 1892, and 1966 produced devastating pyroclastic flows and lahars that caused more than 8000 cumulative fatalities. Awu contained a summit crater lake that was 1 km wide and 172 m deep in 1922, but was largely ejected during the 1966 eruption.
May 18, 2016.Awu , Indonesia :
Source : VSI , GVP.
Photo : Pvgmbh , A Solihin.