Massive Mount Semeru Eruption Sends a 54,000 Foot Ash Cloud Into the Stratosphere

Mount Semeru, the tallest and most active volcano on Indonesia’s Java Island, erupted with extraordinary force on November 19. The blast launched an ash plume more than 54,000 feet into the atmosphere, forcing emergency evacuations across East Java. The eruption created severe hazards for nearby communities and raised significant concerns for aviation throughout Southeast Asia.

Explosive Eruption Triggers Highest Alert Level

The eruption began around 4 p.m. local time when Semeru suddenly released a powerful burst of ash, gas, and volcanic material. Authorities immediately raised the alert to Level IV, which is the highest classification in Indonesia’s warning system. Residents within an eight-kilometer radius were ordered to evacuate as pyroclastic flows swept down the southern and southeastern slopes.

Meteorologists noted that the ash plume rose well above commercial flight levels. Weather satellites showed the column pushing into the lower stratosphere, darkening skies, and spreading quickly across the region.

Ash Cloud Reaches Jet Altitudes and Disrupts Air Travel