Semeru's Eruption and Residents' Actions Approaching Disasters May Trigger the Same Dangers

A video of residents continuously recording the hot cloud mass of Mount Semeru "consuming" the Gladak Perak bridge in Lumajang, East Java, caught the attention of Dwi Setiadi, a resident of Bandung, West Java, on Friday (21/11/2025).

Even though Bandung is 600 kilometers from Gladak Perak, Dwi was annoyed. He was annoyed that his cameraman hadn't immediately left as the pyroclastic flow grew larger. His cellphone camera continued to record the rare event.

"They thought the hot cloud was dangdut gunsmoke. Luckily, the person recording it is fine. But what if the impact is greater or their actions are imitated by others in different areas," Dwi said.

The hot cloud resulting from the Semeru eruption this time is indeed astonishing. Its billows rise high. The iron beams of the Gladak Perak bridge seem to be engulfed in its embrace.

Unlike before, this time the hot cloud reached further, extending up to 13 kilometers. Two years ago, the distance of the hot cloud from the crater was recorded at 11 kilometers.

The video then went viral. It not only reached the residents around Lumajang but also spread to various places thanks to advanced technology. Some appreciated it for the sensational information it provided. However, some circles regretted it. Dwi in Bandung became one of those who were annoyed by the incident.

Not only Dwi, but the Geological Agency also regrets this matter. This government agency oversees the Center for Volcanology and Geological Hazard Mitigation (PVMBG). PVMBG is authorized to determine the status of volcanic activity, including the safe distance for humans.

The Head of the Geological Agency, Muhammad Wafid, reminded not to ever test hot clouds. More than just ordinary fog, hot clouds are extremely dangerous.

Its speed can reach 300 km per hour. Its temperature can exceed 400 degrees Celsius. Not only gas and ash, but hot clouds also carry chunks of hazardous material.

"Avoid all activities solely for content. It is better to seek accurate information regarding what should be done during a volcanic eruption," he said.

In the future, this vigilance must be maintained. Moreover, in several eruption events, Semeru is not easily predictable. This poses a risk of suboptimal mitigation processes.

This year, for instance, the duration of the increase in the status of Semeru occurred rapidly and briefly. After Semeru erupted with a hot cloud on Tuesday (18/11/2025) at 14:31 WIB, PVMBG raised the status of the volcano from Level II or Alert to Level III or Standby. At that time, the eruption had already taken place.

Just an hour later, its status was raised again. At 5:00 PM WIB, the status of Semeru increased from Alert to Level IV or Caution. At that time, hot clouds had already traveled several kilometers.

Volcanology expert Surono stated that the decision to raise the alert status to "Awas" at Semeru could have actually been made earlier. Referring to seismic data from the last 90 days, the alert status should ideally have been established as early as November 15, 2025, and at the latest by November 17, 2025.

During that period, he stated, the number of eruption earthquakes had sharply increased. From the usual range of 100-150 times per day, it rose to above 150 times and exceeded 200 times per day.

This means, he said, that there is pressure in Semeru that is rising sharply, accumulating, and building up. With such data, there is a 90 percent likelihood that Semeru will erupt.

When asked if it is similar to the eruption in 2021, the former head of PVMBG and the Geological Agency stated that the eruption mechanism at that time is different from the current event.

In 2021, Surono stated, the eruption was accompanied by a dome that collapsed due to rainwater. This subsequently triggered the release of gas, fine materials, coarse materials, gravel, and even blocks, culminating in a pyroclastic flow.

"This has nothing to do with the process of increased activity of the volcano. There is no pressure of volcanic activity leading to a major eruption at Semeru. Currently, hot clouds are formed due to the eruption. This process is closely related to volcanic activity, earthquakes, temperature, and gas emissions," he said.

Although not related to increased volcanic activity, the dynamics occurring in Semeru have ended in tragedy. A total of 22 people have died. The majority are residents of Pronojiwo, Lumajang. Several victims were found buried in their homes.

Reflecting on this incident, Surono stated that the best approach in facing the potential eruption of Semeru is not to "confront it." He urged residents not to force themselves to record the eruption for content purposes.

"It is possible that the potential for eruptions due to volcanic activity will increase in the future. A slight delay could put lives at risk," he said.

He also hopes that all settlements in the areas affected by hot clouds in Disaster-Prone Zone III should be relocated immediately. These areas include Supiturang Village and Oro-oro Ombo Village in Pronojiwo District, as well as Sumberwuluh Village in Candipuro District. Both are located in Lumajang.

He is confident that similar or even worse events will occur again. It is not yet known when they will come, but the impacts will certainly be felt by residents who wish to remain in vulnerable areas.

"The point is, don't fight nature," said Surono.

Meanwhile, the trend of residents daring to record or intentionally lingering in disaster areas is also being monitored. The impact may not be any less severe than natural events.

Ranny Rastati, a media researcher at the National Research and Innovation Agency (BRIN), stated that the phenomenon of citizens often approaching and recording disasters can be attributed to several factors.

First, there is an emotional closeness of residents to their living environment. In the context of the eruption of Mount Semeru, for example, residents may perceive the phenomenon of hot cloud avalanches as a rare event that seldom occurs.

They feel like they are part of netizen journalism that records something extreme and interesting, so that it gets attention and social validity.

With such feelings, they want to be direct eyewitnesses and want to be the main recorders of rare historical events (first-hand documentation).

This phenomenon is supported by the abundance of social media channels that can disseminate captured documentation. The impetus is stronger, leading to the sidelining of personal security aspects in the midst of disasters.

"They feel like they're part of netizen journalism, capturing something extreme and interesting, thereby gaining attention and social validity," Ranny said.

Second, there's the term "by-standard risk perception." Simply put, this is the perception that someone is a bystander to something, including a disaster, and feels detached from the danger.

Instead of saving oneself, that perception leads an individual to remain silent and watch the disaster unfold by positioning themselves as a spectator.

In the context of a tsunami, for example, Ranny said, a person is unknowingly hit by a sea wave before they have time to save themselves.

Watching, approaching, and documenting disasters from an unsafe distance is not only risky for one individual. Ranny exemplified this by mentioning a social experiment where someone stopped at the edge of a bridge and looked down at the road below.

The action was gradually followed by passersby, starting with one person and eventually leading to a crowd, which caused a traffic jam. The experiment demonstrated that the act of watching, approaching, and documenting a disaster from an unsafe distance can attract the curiosity of others nearby.

In the context of disasters, this can disrupt the evacuation process of rescue teams. The greater risk is the potential to increase the number of victims from the ongoing disaster.

“When something dangerous happens, it can endanger others who get involved,” he said.

According to records from the National Disaster Management Agency (BNPB), this imitative activity has actually led to the emergence of new disasters. This occurred during a flash flood in the Padang Guci Hulu District, Kaur Regency, Bengkulu on January 19, 2020.

At least 30 residents watched the flash flood from the Cawang Suspension Bridge. Suddenly, the bridge collapsed due to its inability to bear the load. A new disaster emerged. A total of 9 lives were lost and 1 person is missing.

When something dangerous happens, it can endanger others who get involved.

To that end, Ranny recommends that stakeholders be creative in socializing self-rescue during disasters. She emphasizes that this should be conducted periodically in educational institutions.

In addition, he suggested that there should be audio-visual appeals, not just written appeals or announcements through loudspeakers. Through a video, for instance, one can imagine how dangerous it is and the impacts arising from the disasters that occur.

"This educational content for the public can also use digital platforms, such as social media, and can also involve the right influencers," he said.

Potential danger can come from anywhere. If we're not vigilant, both nature and human activity pose similar threats.