Indonesia volcano eruption forces evacuations, spews 54,000ft ash cloud

Indonesia is considered one of the most active volcanic regions in the world, and a recent volcano eruption has sent a 54,000-foot ash cloud into the air, forcing residents to flee for their lives. The event has reportedly led the Japan Meteorological Agency to investigate the possibility of a tsunami following the large eruption.

Mount Semeru, located on the border of the Lumajang and Malang districts in East Java, erupted early this morning at 6:11 a.m. local time.

Around 2:30 p.m. local time, a subsequent and more powerful eruption occurred. The combination of wet and foggy conditions contributed to the formation of hot clouds rising higher. The East Java Regional Disaster Management Agency (BPBD) has evacuated elderly residents from the affected area.

Mount Semeru Observation Post Officer, Mukdas Sofian, stated, “The ash column was observed to be gray with thick intensity to the north and northwest. At the time of this report, the eruption was still ongoing.”

Mukdas also advised residents to stay outside a 2,500-meter radius of the crater to avoid any potential hot rock ejections.

He cautioned the public to be aware of the possibility of hot clouds, lava flows, and lahars (mudflow debris) along rivers and valleys that originate at the peak of Mount Semeru, especially along Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat, as well as the potential for lahars in smaller rivers.

How will the eruption affect flights?

A red aviation warning was issued by the Australia Volcanic Ash Advisory Centre () due to the 54,000-foot ash plume, which is moving at 30 knots in a south-westerly direction.

A red aviation warning indicates that severe impacts are likely and action is required to ensure safety. With volcanoes, actions typically taken to ensure flight safety include diversions, cancellations, and adjustments to flight schedules.

Volcanic ash can pose a substantial threat to flight safety due to its hard and abrasive nature, which can cause damage to aircraft engines, windows, and other components.

In a translated written statement, the East Java BPBD said, “The Rapid Response Team (TRC) of the Lumajang Regency BPBD carried out patrols and helped evacuate the elderly to safer places. The pyroclastic flow is still ongoing, with a maximum amplitude of 40 mm. The pyroclastic flow reached a distance of 8.5 km from the mountain peak. The wind direction is toward the north.”

The Foreign Office states, “Indonesian authorities have set the alert level to 4 (of 4), warning of the potential for hot pyroclastic flows and lava flows along rivers, tributaries, and valleys around Mount Semeru.”

In December 2021, the same volcano erupted, causing the deaths of at least 57 people.