Travel-Time Tomography Imaging around Sinabung Volcano during 2010–2017 Eruption Period

Sinabung Volcano, which never shown any certain volcanic activities since its last eruption in 16th century, suddenly errupted at August 29, 2010. The disaster has not just stopped. Sinabung eruption repeatedly occurred at 2013, 2014, 2016, and 2017, with unstable change of eruption statuses. This research is aimed to identify relationship between Sinabung Volcano recent erruption activities, with distribution of P-wave anomaly around Sinabung Volcano.

Seismic velocity values are derivative form of travel time value. Some factors which influence a seismic velocity condition are lithology type, rock density distribution, rock porosity, rock depth and pressure condition, also fluids saturation in study area. This research was implemented using earthquake travel time data of January 2010-May 2017 period, from Indonesian agency of Meteorology, Climatology and Geophysics (BMKG) earthquake catalog. Data processing was done by Simulps14 program to create distribution map of Vp anomaly from the targeted area.

The result showed that vertical variety of P-wave velocity beneath Sinabung Volcano indicates relation with partial melting zone and fracture which were formed at the end of 2013. This features led Sinabung into big eruption at January 2014.