Indonesia: Authorities raise alert status for Ruang Volcano in North Sulawesi Province due to increased volcanic activity as of April 30 /update 5

Indonesia's Center for Volcanology and Geological Disaster Mitigation (PVMBG) has raised the alert status for Mount Ruang volcano in North Sulawesi Province from level 3 to 4 (the highest level on a four-tier scale) following a powerful eruption at 01:15 April 30. Authorities have increased the exclusion zone around the volcano to 6 km (4 miles). Flight disruptions are ongoing as of the morning of April 30 following the temporary closure of Sam Ratulangi International Airport (MDC) in Manado; further disruptions are likely if eruptive activity continues and winds direct ash clouds toward nearby airports. Previous explosive eruptions at Mount Ruang have led to evacuations and flight disruptions, not only in North Sulawesi Province but also in parts of eastern Malaysia, including Tawau and Kota Kinabalu.

The volcano has erupted more than ten times since April 16, emitting ash clouds at least 2.5 km (1.5 miles) above the crater and lava flowing down its flanks; a magnitude-5.3 earthquake near North Maluku Province at 00:40 April 14 could have triggered the volcanic activity. The eruptions produced a volcanic ash plume that spread volcanic ash to nearby roads and villages, as well as disrupting air travel in the region.

Over 11,000 residents of Ruang and southwest Tagulandang islands have been evacuated in recent weeks due to the threat of ashfall, pyroclastic flows, other volcanic material, and seismically triggered landslides around the volcano. Around 500 homes and other buildings in affected areas have suffered varying degrees of damage caused by the eruptions. The PVMBG has also issued a warning for potential tsunamis on Tagulandang Island if parts of the volcano could collapse into the sea.

Additional small-scale eruptions could cause low-level seismic activity, ash clouds, pyroclastic flows, and landslides in the surrounding area. Road conditions could quickly deteriorate during periods of significant ashfall, and visibility could be reduced. Officials may close roads near the volcano depending on the presence of hazardous volcanic material. Fine particulate matter ejected from the volcano could continue to pose a hazard to flights in the surrounding airspace.

Further volcanic activity may impact air quality in North Sulawesi Province and neighboring areas. Individuals in the region - especially those with underlying pulmonary conditions such as asthma, chronic obstructive pulmonary disease (COPD), or lung cancers - may experience difficulty breathing and could suffer from lower tolerance to physical exertion.