Mount Semeru, the tallest volcano on Java, Indonesia, has erupted multiple times over the past two days, showcasing increased volcanic activity and prompting authorities to issue safety warnings to nearby residents. On December 26, 2024, the volcano erupted four times between the hours of 00:00 and 09:00 WIB, marking another chapter of its geological volatility.
The first eruption occurred at 04:58 WIB, producing moderate smoke emissions which reached heights of 600 meters and drifted northward. Just 29 minutes later, at 05:27 WIB, the eruption column climbed higher, measured at 1,100 meters. The third eruption at 06:19 WIB recorded ash emissions rising up to 1,000 meters with seismic activity reflecting amplitudes of 22 millimeters for durations of around two minutes. The last eruption at 08:34 WIB could not be visually monitored due to fog, but seismographs confirmed its occurrence.
Liswanto, reporting from the Pos Pemantauan Gunung Api (PPGA) Semeru, highlighted the intensity of the earlier eruptions, noting, "Terjadi erupsi Gunung Semeru pada hari Kamis, 26 Desember 2024 pukul 05.27 WIB dengan tinggi kolom abu teramati 1.100 meter di atas puncak," which translates to "There was an eruption of Mount Semeru on Thursday, December 26, 2024 at 05:27 WIB with the ash column observed at 1,100 meters above the summit." Notably, the volcanic activity prior to this included 64 eruptions and one hot cloud event recorded within the preceding 24 hours.
On December 25, 2024, the activity was marked by 16 eruptions throughout the day, with the highest ash column sampled at 1,500 meters. The eruption, occurring just before the evening hours at 20:07 WIB, was detailed by Liswanto, who stated, "Tinggi kolom letusan teramati sekitar 700 meter di atas puncak," signifying the ash clouds' evolution across the day.
Authorities remain vigilant as Mount Semeru's alert status is set at Level II, indicating caution. Yudhi Cahyono from the Badan Penanggulangan Bencana Daerah (BPBD) reassured the community stating, "Dengan kondisi saat ini, di sekitar Gunung Semeru sering terjadi hujan lebat yang berisiko menimbulkan banjir lahar," urging residents to avoid the Besuk Kobokan sector, extending 8 kilometers from the peak.
Alongside reminders not to engage in activities within 500 meters of riverbanks near Besuk Kobokan, residents are also warned to expect potential hazards from hot clouds and lahar flows, which threaten to reach 13 kilometers from the volcano. The local community's response is guided by advice from the Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), focusing on safety measures.
The potential geological risks remain heightened due to heavy rains persisting around Mount Semeru, raising the likelihood of lahar floods—rapid, highly destructive flows of volcanic debris mixed with water. This prospective threat amplifies calls for safety, with alerts issued for Bansari, along with other sectors at risk of volcanic debris flow.
The community around Mount Semeru is advised to stay informed about the geological developments, as the situation continues to evolve. Residents are encouraged to follow official updates closely and maintain preparedness amid the unpredictable nature of volcanic activity.
With each eruption, the geological monitoring reveals both the beauty and danger presented by Mount Semeru, underscoring the need for continuous vigilance and action to protect those living nearby from its powerful natural forces.
