Toxic Gas Emissions Continue at Indonesia's Mount Papandayan After Rare Blue Fire Amid Natural Disasters
Indonesian authorities have warned of toxic volcanic gas emissions at Mount Papandayan in West Java after a rare "blue fire" phenomenon appeared in its Manuk Crater amid ongoing natural disasters concerns, with the event first observed on September 24, 2026. [1] The blue fire was triggered by volcanic gas concentrations exceeding safe health limits. [2]
Blue Fire Phenomenon at Mount Papandayan
The blue fire at Manuk Crater on Mount Papandayan was observed on September 24, 2026. [2] Head of the Geological Agency Lana Saria stated that an emergency response team from the Center for Volcanology and Geological Hazard Mitigation found the blue flames were caused by a sudden intense release of underground heat. [1] The blue fire burned surface materials and left behind ash. [1] Direct inspections by the Geological Agency's expert team found the release of volcanic gases exceeding safe health limits, such as sulfur dioxide reaching 230 ppm and hydrogen sulfide at 120 ppm. [2] The bluish flames occur when high-temperature sulfur gas escaping through fumarole cracks reacts chemically with oxygen in the air. [2] The extremely high temperatures and gas concentrations could also ignite sulfur deposits on the crater walls. [2] While the flames had died down by September 26, the crater continues to release dangerous levels of volcanic gas. [1]
Ongoing Volcanic Gas Hazards
Despite a decrease in thermal activities, significant toxic gas emissions continue around the site. [1] A strong sulfur odor can still be smelled downwind, posing health risks to anyone directly exposed. [1] The blue fire phenomenon on Mount Papandayan was triggered by high-temperature volcanic gas released at concentrations exceeding normal limits levels. [2] The phenomenon at Mount Papandayan differs from that at Mount Ijen, where sulfur concentrations in solfatara vents remain consistently high. [2] At Papandayan, the phenomenon is relatively rare and occurs only when specific temperature and gas concentration conditions are met. [2] Visitors must not stay overnight or conduct any activities within a 500-meter radius of the active craters, especially on cloudy or rainy days. [1]
Blue flames from high-concentration volcanic gas burn at Mount Papandayan's Manuk Crater. — Source: antaranews
Safety Warnings and Restrictions
While Mount Papandayan's overall alert level remains at Level I (Normal), the Geological Agency has issued strict safety guidelines for visitors and park management. [1] The PVMBG has set a recommended safe distance of 500 meters from the active crater of Mount Papandayan and prohibits camping in gas-sensitive areas to ensure the safety of visitors and climbers. [2] Tourists are also urged to beware of sudden eruptions, as phreatic eruptions can occur without warning, as well as the threat of landslides on the crater walls surrounding the active crater complex. [1] The agency urged Mount Papandayan Nature Park management to strictly enforce the 500-meter safety zone to protect hikers and prevent people from wandering into areas with toxic gas. [1] Tourists and the public are advised to monitor official volcanic activity updates through PVMBG's official channels and the magma.esdm.go.id portal. [1] "We may enjoy the phenomenon, but we remind the public to also heed the recommendations for the sake of everyone's safety, particularly because the active crater at Mount Papandayan can release volcanic gases that may pose health risks," Rita Susilawati said. [2]
Comparison to Prior Events and Mount Ijen
The blue fire is a rare event at Mount Papandayan. [1] It has only been recorded twice before on February 22, 2023, and July 12, 2025, and is identical to the famous phenomenon at Mount Ijen in East Java. [1] The Geological Agency recorded a similar phenomenon occurring at Baru Crater on February 22, 2023, and July 12, 2025, while in 2026 it was found in Manuk Crater. [2] The latest blue fire in Manuk Crater appeared dangerously close to main hiking trails and tourist camping grounds, prompting the agency to issue a safety warning. [1] At Papandayan, the phenomenon is relatively rare and occurs only when specific temperature and gas concentration conditions are met. [2]
Anak Krakatau Activity and Future Risks
Mount Anak Krakatau currently lies in an "incubation" period after a series of major eruptions on September 4-6, 2026. [3] Based on the magma composition, subsurface structure such as magma chamber depth, and eruption patterns, Anak Krakatau has returned to the early stage of the volcanic maturation phase. [3] A researcher at the Geological Disaster Research Center of the National Research and Innovation Agency, Aditya Pratama, explained that Anak Krakatau's magma contains a small amount of sulfur dioxide during this incubation phase, which builds up as it approaches maturation. [3] At this phase, Anak Krakatau will erupt frequently, albeit with lower intensity. [3] Models created by Aditya and his research team show shallow magma pockets beneath Anak Krakatau. [3] Upon maturation, these pockets will merge into a large magma chamber at shallow to deep depths. [3] In contrast to the incubation phase, a large-scale eruption occurs when it reaches maturation. [3] Mount Anak Krakatau's shallow magma chamber is located at a depth of less than 10 kilometers from the summit. [3] The medium depth ranges from 7-15 kilometers, while the deep magma chamber is located at 22-25 kilometers. [3] Their concern does not lie with the major eruption itself, but with the potential landslide from this underwater volcano that could trigger a tsunami, similar to what happened in 2018. [3] Based on the latest modeling results conducted by a team at BRIN in collaboration with ITB, PVMBG, University of Birmingham, Penn State University, British Geological Survey, and University of Oxford, a similar landslide is estimated to occur in 2036. [3] After the major eruption on September 4–6, this change might accelerate, leading to an earlier eruption with a landslide before 2036. [3] The eruptive history of Anak Krakatau shows that this volcano evolves through cycles of growth, eruption, collapse, and reconstruction. [3] Anak Krakatau emerged in the ocean in 1927 after the collapse of Krakatau during the 1883 eruption. [3] Continuous accumulation of deposits eventually formed a permanent landmass of Anak Krakatau, which emerged above sea level in August 1930. [3] A significant change in growth occurred on December 22, 2018, when the southwestern sector of Anak Krakatau collapsed into the sea, with a volume of around 0.116 cubic kilometers of material. [3] As of September 21, Mount Anak Krakatau's volcanic activity has been downgraded into Alert Level II. [3]
Monitoring and Official Recommendations
The agency urged Mount Papandayan Nature Park management to strictly enforce the 500-meter safety zone. [1] Tourists and the public are advised to monitor official volcanic activity updates through PVMBG's official channels and the magma.esdm.go.id portal. [1] Mount Anak Krakatau in the Sunda Strait experienced another eruption on September 5, 2026 at 00.01 WIB. [3] The calculations for the 2036 estimate are based on the history of volcanic activity in the Sunda Strait, which experienced an extreme eruption in 1883. [3]
What to watch next: Models indicate the potential landslide-tsunami timeline could accelerate before 2036 following recent activity shifts at Anak Krakatau, while PVMBG continues to track gas concentrations at Mount Papandayan.
