Sinabung Volcano on Sumatra Ejects 3,500-Meter-High Ash Cloud

Mount Sinabung is one of Indonesia's most active volcanoes and is located around 50 kilometers northwest of the major city of Medan. The mountain had reawakened after a longer dormant phase in 2010 and caused repeated closures and evacuations in the years that followed. In recent years as well, eruptions and ashfalls occurred again and again.

Background: Sinabung is among Indonesia's most active volcanoes

The PVMBG established an exclusion zone of several kilometers in radius around the crater. Tens of thousands of people live in the area, many of whom depend on growing coffee, vegetables, and spices in the fertile volcanic soils. During past eruptions, villages had to be evacuated repeatedly.

Indonesia lies on the edge of the so-called Pacific Ring of Fire, where around 90 percent of the world's earthquakes occur. According to observers, Indonesia has about 130 active volcanoes – most of them on the densely populated islands of Java and Sumatra. Mount Sinabung has been among the most closely monitored volcanoes in the country for years.

Airlines and the airport in the regional capital Medan were monitoring the situation. Ash clouds can affect engines and visibility and therefore lead to route changes or temporary closures. No concrete impacts on air traffic were initially reported.

Authorities' measures and consequences for the population

Local disaster management agencies mobilized rescue workers and vehicles to assist residents in the event of a possible evacuation. According to reports, spaces in emergency shelters were prepared in case people had to leave their homes.

Mount Sinabung is considered one of the most unpredictable volcanoes on Sumatra. After the resurgence of activity in 2010, the mountain claimed dozens of lives in later eruptions and devastated large parts of the surrounding agricultural land. Authorities emphasize that the alert levels are based on current measurements and can be adjusted quickly.

The PVMBG announced further observations for the coming days. Should activity increase, an escalation to the highest alert level is possible. Residents were urged to follow the instructions of local authorities and to monitor official warnings via radio and social media.