Direction of magma migration in Sinabung volcano based on February 2017 hypocenter distribution

摘要

After laying dormant for 1200 years, Sinabung volcano experienced its first phreatic eruption on August 27, 2010, and remains active today. The increased activity encouraged the Center for Volcanology and Geological Hazard Mitigation (CVGHM) to conduct monitoring, which began on August 29, 2010. It is necessary to map the distribution of earthquake hypocenter on Sinabung volcano to find out the path of magma migration. In this study, a mapping of earthquake hypocenter distribution was carried out using February 2017 data to determine the path of magma migration on Sinabung volcano. The temporal variation of the hypocenter distribution will indicate the direction of the magma movement, which can be one of the mitigation efforts for the community around Sinabung volcano. P wave and S wave arrival time information observed by at least 4 stations were used to determine the earthquake hypocenter distribution. The initial hypocenter was located using hypomh software, then relocated using hypoDD. The results showed that the hypocenter distribution was concentrated northeast of Sinabung volcano at a depth of 5-15 km below sea level. The temporal variation of the hypocenter showed that magma was moving deeper towards the northeast from Sinabung volcano towards Sibayak volcano with a speed of 179.6679 m/day.