Indonesia: Fast-moving hot gas, volcanic matter caught on video, threaten villages

A dramatic video released by Indonesian authorities captured a harrowing pyroclastic flow from Mount Merapi, one of Indonesia's most active volcanoes, racing approximately 1,000 metres toward the Kali Putih river.

The footage, shared on Wednesday (October 1, 2025) by the Balai Penyelidikan dan Pengembangan Teknologi Kebencanaan Geologi (BPPTKG), Indonesia's geological research centre, has gone viral, drawing global attention to the ongoing volcanic threat.

Mount Merapi, located on the border between Central Java and Yogyakarta, has been at a heightened Level 3 alert since late 2024, with increased seismic activity and lava dome growth prompting continuous monitoring.

The recent pyroclastic flow, a fast-moving current of hot gas and volcanic matter, underscores the volcano's persistent danger to nearby communities.

Indonesian officials have maintained a 5-km exclusion zone around the crater and are urging residents to follow safety protocols.

The BPPTKG's video serves as a stark reminder of Merapi's volatility, which has seen multiple eruptions in the past decade, including significant events in 2010 and 2020.

As the world watches, Indonesia's vulnerability to volcanic eruptions, exacerbated by its position on the Pacific Ring of Fire, remains a critical concern.

The viral video highlights the raw power of nature and the tireless efforts of authorities to mitigate risks and protect lives.

Mt Merapi has demonstrated increased volcanic activity, including lava dome growth and frequent lava avalanches, prompting ongoing monitoring and public safety measures.

The BPPTKG's footage is part of a broader effort to track Merapi's activity, which has seen heightened seismicity and multiple pyroclastic flows since early 2025, reflecting the volcano's persistent threat to nearby communities.