Mount Semeru,one of Indonesia’s most active volcanoes,erupted on Wednesday,prompting the highest level of alert and a scramble for safety among residents in East Java. The eruption, which sent a hot cloud cascading down the mountainside and triggered widespread panic, comes as the region is already grappling with the aftermath of recent landslides [[2]]. authorities have now raised the volcano’s status to Level IV, signifying a major eruption is underway or imminent, and have begun evacuating vulnerable communities.
Mount Semeru in East Java, Indonesia, erupted Wednesday, November 19, 2025, prompting authorities to issue the highest level of alert and sending residents scrambling for safety. The powerful eruption triggered widespread panic, with reports of residents screaming as they fled the approaching volcanic activity.
Here are the key facts surrounding the eruption:
1. Hot Cloud Erupts Over 3 Miles
Table of Contents
The volcano launched a hot cloud as far as 5.5 kilometers (approximately 3.4 miles). According to reports, the cloud traveled from the crater towards the Besuk Kobokan area.
SCROLL TO CONTINUE WITH CONTENT
The ash column was described as dense gray, moving northwest. Seismic instruments at the Mount Semeru observation post recorded an amplitude of up to 40 mm, lasting 16 minutes and 40 seconds.
“Mount Semeru released a hot cloud as far as 5.5 kilometers towards Besuk Kobokan,” said Isnugroho, head of the Lumajang Regency Regional Disaster Management Agency.
2. Alert Level Raised
Indonesia’s Geological Agency has raised the alert level for Mount Semeru to Level IV, the highest designation, signifying a major eruption is either underway or imminent. The status was elevated from Level II (Caution) to Level IV (Alert) at 5:00 PM local time on Wednesday.
“We are informing you of an increase in the activity level of Mount Semeru from Level III (Siaga) to Level IV (Alert) at 5:00 PM WIB,” said M Wafid, head of the Geological Agency.
Authorities are advising the public to avoid all activity within a 5-mile radius of the summit or eruption center. Residents are urged to be aware of the potential for hot clouds, lava flows, and lahars along rivers and valleys originating from the volcano’s peak.
3. Panic and Hysteria Among Residents
The powerful eruption of Mount Semeru sent a hot cloud surging as far as 8 miles, reaching the Gladak Perak Bridge and causing widespread panic.
Video footage circulating online shows the scene near the Gladak Perak Bridge quickly becoming chaotic as the hot cloud descended into the valley. Residents who had been observing from a distance suddenly ran for cover as a thick plume of ash rapidly approached the bridge.
Screams and cries for help filled the air, with people calling out to family members and urging others to seek higher ground. Motorcyclists were seen speeding away in search of safety.
The hot cloud reached a radius of 13 kilometers, impacting the Curah Kobokan and Kali Lanang rivers, as well as the Besuk Lengkong area in Supit Urang Village, Pronojiwo District, Lumajang Regency.
Residents of Dusun Kamar A, also in Supit Urang Village, immediately panicked and evacuated to safer locations. Emergency personnel are continuing to monitor the situation.
Ali Murtopo, a resident of Sumber Sari Village, said the hot cloud began erupting at 2:13 PM local time, causing panic and forcing miners to flee to safety, halting mining activities in the rivers affected by the cloud.
“The hot cloud from Mount Semeru caused residents near the mountain to run for safety, and we ordered miners to stop their work. Even residents in government-built housing, impacted by last year’s eruption, panicked,” Ali said.
4. Hiking Trails Closed
The Great Bromo Tengger Semeru National Park (BB TNBTS) has completely closed all hiking trails on Mount Semeru following the eruption. The decision is based on recommendations from the Geological Agency, which raised the volcano’s alert status to Level IV.
Rudijanta Tjahja Nugraha, head of the BB TNBTS, stated that the closure is a precautionary measure to avoid potential risks to hikers and nearby communities. He explained that the Level IV status indicates a significant eruption hazard.
Rudijanta added that authorities are advising the public to stay at least 5 miles away from the summit of Mount Semeru.
Residents are also being warned about a potential hazard zone extending 12 miles to the south-southeast, which could be affected by volcanic material flows.
“Considering the current conditions and recommendations from the Volcanology and Geological Hazard Mitigation Center, climbing Mount Semeru, including trails to Ranu Kumbolo, is closed until further notice,” Rudijanta said.
5. Lumajang Regency Declares 7-Day State of Emergency
Following Mount Semeru’s eruption and its Level IV alert status, the Lumajang Regency government has officially issued a decree declaring a 7-day state of emergency for natural disasters.
According to reports, the decree, numbered 6 of 2025, was sent to all regional heads, sub-district heads, village heads, and the public.
“I hereby declare a state of emergency for the natural disaster of the Mount Semeru eruption through Bupati Decree Number 100.3.3.2/595/KEP/427.12/2025. This decision is valid for 7 days, from November 19 to November 25, 2025, as a swift and coordinated response to the eruption’s impact,” said Lumajang Regent Indah Amperawati.
Key points of the decree include increasing vigilance regarding the eruption’s developments and impacts, and taking precautions by seeking temporary shelter to avoid the eruption’s effects while awaiting further updates.
“Sub-district heads and village heads are asked to secure and direct their residents, while coordinating with other authorities to ensure an optimal response,” she said.
6. 178 Hikers Stranded at Ranu Kumbolo
Approximately 178 hikers are currently stranded at Ranu Kumbolo due to the eruption of Mount Semeru. The National Disaster Management Agency (BNPB) is preparing to deploy a team to assist with evacuations.
“Of course (we will evacuate the hikers from Mount Semeru),” said BNPB Chief Lieutenant General Suharyanto.
He stated that the evacuation team will be led by Deputy 1 and will also focus on emergency response efforts in the area.
“As I am currently in Cilacap and Banjarnegara dealing with the aftermath of landslides, the BNPB team, led by a Level 1 official (Deputy 1), will depart tomorrow morning to directly lead all emergency response activities,” he said.
Suharyanto reported that around 300 people have been displaced to three locations. He added that there have been no reports of casualties or injuries as a result of the eruption, and he hopes that remains the case.
“Currently, 300 people are displaced at three locations: approximately 200 in the Oro-oro Ombo Village Hall, the Penanggal Village Hall is still being assessed, and around 100 in the Supiturang 2 Elementary School,” Suharyanto said.
Watch DetikPagi Live:
Watch Video ‘Mount Semeru Erupts, Here’s an Appeal from BNPB’:
Page 2 of 5
(whn/isa)
