Pyroclastic flow on Mount Sinabung, Indonesia – July 27, 2015

Effusion of viscous lava continues at slow pace to feed the lava dome with two active lobes on the SE and E upper flanks of Indonesian Sinabung volcano.

At 12:22 local time today, a small part of the eastern lobe collapsed into a medium-sized pyroclastic flow that traveled approximately 2.5 km (1.55 miles) towards the outskirts of the (already evacuated and destroyed) villages of Bekerah and Simacem, Volcano Discovery reports.

Video courtesy of Ingrid Smet / Volcano Discovery.

During July 18 to 19, BNPB reported pyroclastic flows traveled 2.5 -3 km (1.86 miles) E and SE, ash plumes rose as high as 1 km (0.62 miles), and lava was active as far as 1.5 km (0.93 miles) SE. Seismicity was high and the lava dome continued to extrude.

A total of 11 111 people (3 150 families) remained displaced. The Alert Level remained at 4 (on a scale of 1 to 4). Based on satellite images, weather models, and information from PVMBG, the Darwin VAAC reported that during July 18 to 20 explosions generated ash plumes that rose to an altitude of 3.7 km (12 000 ft) a.s.l. and drifted E. White plumes rose 200 m (656 feet) on July 21.

Geologic summary

Gunung Sinabung is a Pleistocene-to-Holocene stratovolcano with many lava flows on its flanks. The migration of summit vents along a N-S line gives the summit crater complex an elongated form. The youngest crater of this conical, 2460-m-high andesitic-to-dacitic volcano is at the southern end of the four overlapping summit craters.

An unconfirmed eruption was noted in 1881, and solfataric activity was seen at the summit and upper flanks in 1912.

No confirmed historical eruptions were recorded prior to explosive eruptions during August – September 2010 that produced ash plumes to 5 km above the summit. (GVP)

Featured image: Pyroclastic flows on Mount Sinabung – July 27, 2015. Credit: Ingrid Smet / Volcano Discovery.