Apriadi Gunawan, Medan – The alert level for North Sumatra's Mount Sinabung has been lowered from siaga (watch), or level three of the country's four-tiered alert system, to level two, waspada (advisory). The volcano had been on level three for three years.
According to Mount Sinabung monitoring post officer Armen Putra, the Volcanology and Geological Hazard Mitigation Center (PVMBG) made the decision following a decrease in volcanic activity. The PVMBG has lowered Sinabung's alert level since Tuesday.
"However, the local people need to remain cautious, because we still have eruptions from time to time," Armen said on Wednesday.
Local residents are still forbidden from the relocated village areas as well as areas declared red zones. People living along streams of rivers with headwaters in the volcano area are reminded to remain cautious.
"Millions of cubic meters of volcanic material are piling up on the mountain side, therefore there's a risk of lahar flow during heavy rains," Armen said.
The most recent Mt. Sinabung eruption was in July 2021, spewing volcanic ash 4.5 kilometers upward and hot pyroclastic flow 1 km to the east-southeast. At least five districts were affected by the eruption.
Sinabung also erupted in May 2021, sending volcanic ash 2.8 km eastward.
The 2,460 m volcano was dormant for centuries before roaring back to life in 2010 when an eruption killed two people.
It erupted twice in 2013, in September and November, with the second eruption killing dozens of people and leading to evacuation of thousands of residents from 21 villages and two hamlets from within the 5 km radius of the volcano.
The volcano was put on the highest alert level following the November 2013 eruption, before being lowered to level three in 2019.
Indonesia currently has around 130 active volcanoes.