Malang Residents Alarmed by Mysterious Loud Bangs, BMKG Provides Explanation

Residents in several areas of Malang Raya, East Java, were surprised by loud booming sounds heard on Tuesday night (8/9). Initial suspicions pointed towards the activity of Mount Semeru, located in the region.

The appearance of the sound initially led residents to suspect it originated from ‘sound horeg’ (large mobile sound systems) or construction activities near residential areas. However, reports from residents indicated that similar sounds were heard almost simultaneously in several widely separated locations.

According to reports, the booms were heard in various areas, ranging from Blimbing, Bumiayu, and Lowokwaru in the Malang urban area, to Lawang and Bululawang in the Malang Regency.

Responding to this incident, the Head of the BMKG Geophysical Station, Ricko Kardoso, explained that the loud noise did not originate from tectonic earthquake activity or lightning strikes. Monitoring by BMKG instruments at the time of the incident showed that the seismic and atmospheric situation in Malang Raya showed no extreme phenomena.

“The monitoring results from the BMKG Malang Geophysical Station regarding tectonic earthquake activity and lightning strikes around 22:00 WIB showed no detected tectonic earthquake activity or lightning strikes in the Malang area and its surroundings at that time that could potentially cause booming sounds,” said Ricko, as quoted on Thursday (10/9/2026).

He stated that his office has coordinated with the Mount Semeru Volcano Observation Post under the PVMBG. The findings revealed that Mount Semeru has recently shown an increase in volcanic gas pressure.

This condition triggers the occurrence of booming sounds and rumbles that can be heard from a considerable distance.

“The eruption activity of Mount Semeru in recent weeks has occasionally been accompanied by booming sounds or rumbles of weak, moderate, to strong intensity, related to the increase in volcanic gas pressure,” explained Ricko.

Based on this data, the Malang Geophysical Station confirmed that the booming sounds in Malang Raya are purely related to the volcanic dynamics of Mount Semeru and are not the result of earthquakes or lightning.