Pyroclastic flows at Sinabung volcano, evacuations ordered, Indonesia

Pyroclastic flows with slide distances of 1.5 and 2.5 km (0.9 – 1.5 miles) were observed at Sinabung volcano, Sumatra, Indonesia on Sunday, October 25, 2020, prompting authorities to evacuate nearby settlements.

The Center for Volcanology and Geological Hazard Mitigation (PVBMG) said the first flow was produced at 12:51 LT to a distance of some 1.5 km (0.9 miles), while the second took place at 20:58 LT on the same day to a distance of 2.5 km (1.5 miles).

Muhammad Nurul Asrori of the Mt. Sinabung observation post said lava dome at the volcano keeps growing, urging residents to be cautious because further pyroclastic flows are possible, even larger ones.

PVMBG said many residents decided to stay on the mountain slopes and urged them to leave before it's too late.

"It might be best for us to avoid the volcano because no one can survive the fast ash clouds from Mt. Sinabung's craters," Asrori added.

Lahars are another danger posed by this volcano, so people living near Sinabung's drainages should be aware of that danger, too.

The alert status remains at 3 (Siaga / Watch).

Geological 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, 2 460-m-high (8 070 feet) 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 (16 404 feet) above the summit. (GVP)

Featured image credit: Tribun Timur