Seismicity at Talang had generally declined since February 2009. However on 16 August 2009 there was a M 6.9 earthquake centered W of Sumatra in the southern part of Siberut Island. That event caused tremors recorded at Talang. Increased seismicity through the next day led to CVGHM to raise the Alert Level for Talang from 2 to 3 (on a scale of 1-4). Monitoring was also stepped up, and an emergency response team was assigned to conduct an onsite evaluation. Foggy conditions prevented visual observations.

Between the August activity and February 2010, Talang was comparatively quiet; however in early February another episode of increased seismicity included harmonic tremor, shallow volcanic earthquakes, and deep volcanic earthquakes. By 17 February the elevated seismicity had subsided. MODVOLC satellite surveillance has shown no indications of any thermal activity.

Geological Summary. Talang is part of a large volcanic edifice just NW of Dibawah Lake. An older volcanic peak, Pasar Arbaao, is ~1.5 km W. The steep-sided Talang cone exhibits fumarolic activity but has no crater; it appears to have grown within a larger caldera. Recorded eruptions have mostly involved small-to-moderate explosive activity, first documented in the 19th century, that originated from a series of small craters in a valley on the NE flank.

Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (URL: http://vsi.esdm.go.id/).