What tells us today the seismicity of Gunung Sinabung ?
Seismicity has decline 31 August in comparison with that of the previous week ... this reduction is to be linked with the almost total disappearance of the lava dome.
Hybrid-type earthquakes with a magnitude of 2-3 mm followed on 31 August, marking the formation of the new lava dome. It can reform within a few days. In May, just in a week, the dome has reached a volume of 2.6 million m³ ... indicating the persistence of the pressure and the supply of energy from the magma chamber.
Other types of earthquakes, low frequency, volcanic or tectonic type, still manifest. The observation of four low frequency earthquakes indicates the presence of flowing fluids from the crater.
The requirements for the red zone have not changed; of three km around the crater, it extends to 4 km north and east, and to 7 km in the south and southeast sectors.
Source: DPDT Kab Blitar and pictures of observers.