Significant Spike, Geological Agency Records Increased Earthquake on Mount Tangkuban Parahu

JAKARTA - The Geological Agency of the Ministry of Energy and Mineral Resources (ESDM) recorded a significant spike in Low Frequency (LF) seismic activity at Mount Tangkuban Parahu, which increased threefold in just 24 hours in the observation period of December 26, 2025.

Acting Head of the Geological Agency, Lana Saria, in a statement received in Bandung, Saturday, revealed that the seismic recording on December 26, 2025 detected 38 LF Earthquake events.

This figure jumped sharply compared to the previous two days, namely December 24 and 25, which only recorded 10 cases per day.

This drastic increase in earthquakes has become a major highlight considering the position of Mount Tangkuban Parahu as a flagship tourist destination that is crowded with visitors during the year-end holidays.

Although the activity level is still set at Level I (Normal), data on the deformation of the volcano's body show anomalies that should be watched.

"EDM monitoring data shows a tendency for deflation patterns in the Pillar-UPAS segment but inflation in the Pillar-LERENG segment. This indicates fluctuations in pressure at shallow depths below the volcano," said Lana.

The condition of this shallow pressure fluctuation, according to the Geological Agency, holds hidden potential dangers. Although seismic monitoring at dV/V values has not shown a significant pattern of decline, which means that there is no massive pressure due to a large fluid rise to the surface, the characteristics of the Tangkuban Parahu eruption are often freatic.

A phreatic eruption has a special character that is dangerous for tourists who are too close to the crater, where it can occur suddenly without being preceded by clear volcanic symptoms or visible early warning signs.

Visually, until December 27, 2025, the activity of the smoke blowing from the Ratu Crater was observed to be white with thin to moderate intensity, reaching a height of 5-80 meters from the crater floor. Meanwhile, the Ecoma Crater blew smoke as high as 5-40 meters.

Looking at the history of activity in the middle of this year, namely the period June-July 2025, the increase in LF earthquakes reached its peak with 270 events on June 3, which was then followed by the phenomenon of mud flow in the Ratu Crater.

Based on the latest data, the Geological Agency appeals to the public and tourists not to approach the crater floor area and not to linger in the area of the active crater rim.

"If you observe an increase in the intensity of the smoke or smell of pungent gas, the public is asked to immediately move away for safety," said Lana.

The Regional Government and the West Bandung Regency and Subang BPBD are asked to continue to coordinate intensively with the Tangkuban Parahu Volcano Observation Post in Cikole Village to monitor the development of this dynamic situation.