After a cluster of volcanic activity in Indonesia and the explosive eruption of Mount Anak Krakatau in the Sunda Strait, old videos resurfaced in posts falsely claiming they showed the recent eruptions. The clips in fact show Anak Krakatau erupting in October 2018, and Mount Sinabung spewing smoke and ash thousands of metres into the sky in February 2018.
"Mount Anak Krakatau erupted on Sunday, September 6, sending around volcanic ash plumes up to 50,000 feet (15.2 km)," says part of the caption of a Facebook video shared on the same day.
The video shows a night-time volcanic eruption that sends lava and ash into the air.
Another dramatic video, showing schoolchildren running as massive clouds of volcanic ash rise in the distance, was shared in a similar Facebook post on September 10.
"Six volcanoes erupt simultaneously in Indonesia; threat level rises in several areas," says its Hindi-language caption.
The clips were also shared in similar Facebook and X posts after six Indonesian volcanoes erupted at the end of August, a phenomenon the country's geological agency said was a coincidence ( archived link).
Indonesia's location on the Pacific Ring of Fire and its 127 active volcanoes made it possible for several volcanoes to erupt on the same day without being systematically connected, said the head of the Centre for Volcanology and Geological Hazard Mitigation, Rita Susilawati.
One of the six, Mount Anak Krakatau, experienced another continuous explosive eruption in early September, which for days paralysed several airports and blanketed cities including Jakarta in volcanic ash (archived here and here).
Anak Krakatau -- meaning Child of Krakatau -- has been sporadically active since it emerged from the sea nearly a century ago in the caldera formed after the 1883 eruption of Mount Krakatau.
The circulating clips, however, do not show the recent volcanic activity.
A reverse image search on Google using keyframes from the video showing a night-time eruption led to a longer, uncropped YouTube video published on November 6, 2018 ( archived link).
The video is titled "Krakatau at night", and its caption says it shows Anak Krakatau's volcanic activity sometime between October 24 and 26 in 2018.
The falsely shared clip was zoomed in and sped up from this footage.
The video was published on the YouTube channel of Martin Rietze, a photographer and videographer who frequently shares images of volcanic eruptions (archived here and here). He posted the same clip on his website ( archived link).
AFP reached out to Rietze for comment, but did not receive a response by time of publication.
The collapse of parts of Anak Krakatau, which sits in a strait between the islands of Java and Sumatra, a couple of months later in December 2018 triggered a tsunami that killed more than 400 people and displaced thousands.
Video agency Newsflare also distributed the footage on its YouTube channel on November 4, 2019, saying it was captured on October 25, 2018 ( archived link).
A separate reverse image search using keyframes from the video showing schoolchildren running from a massive ash cloud led to footage published on YouTube on February 20, 2018 by Indonesian broadcaster Kompas TV ( archived link).
The Indonesian-language caption says the video shows students from the Naman Teran State Elementary School in North Sumatra after Mount Sinabung erupted the day before.
The volcanic eruption sent a massive column of smoke and ash about 5,000 metres into the air ( archived link).
Stills from the video were also included in local news reports about Mount Sinabung's eruption (archived here and here).
The falsely shared video corresponds to Google Street View imagery from near the elementary school ( archived link).
AFP has previously debunked other misleading claims about volcanic eruptions in Indonesia.