Mount Sorik Marapi entry classification type A, is geographically located the position of 0o 40 ’27 “North Latitude 99o 30′ 24” east longitude with a peak height of about 2145 m above sea level. This volcano is monitored from the Post in the PGA Village Sibangortonga, District Pucuk Sorik Marapi, Mandailing Natal regency.

Eruptive activity Mount Marapi Sorik last recorded in 1971 ash eruption. In normal conditions, the number of recordings Volcanic Earthquake In (VA) less than 10 occasions per month, whereas Shallow volcanic earthquake (VB) during the year 2011 nil.

Based on observation and analysis of seismic data, G. Sorik Marapi increase since December 11, 2011 at 17:00 pm, an increase in volcanic earthquakes continued on the next day.

Based on seismic data, then the date of December 12, 2011, 16:00 pm, the status of activities of G. Sorik Marapi raised from Normal (Level I) to be alert (Level II).