A wildfire in Indonesia’s Bromo Tengger Semeru National Park, in East Java, has been extinguished after burning around 550 hectares. New hotspots have been reported near the caldera.

“Extinguished” is not the end

The most useful detail in that report is the second sentence. A fire declared out, with hotspots still appearing nearby, is a normal and dangerous situation rather than a contradiction.

Fire moves underground as well as across the surface. Roots, peat and deep organic soil can smoulder for days or weeks after the visible flames are gone, producing little smoke and no glow. When wind and dry conditions return, that buried heat surfaces as a new fire, sometimes hundreds of metres from where the original was fought.

This is why fire services distinguish between a fire being contained, controlled and fully out — and why crews stay on site long after the news has moved on.

Why a volcanic park burns

Bromo Tengger Semeru is built around an active volcanic landscape — a vast caldera holding a sea of volcanic sand, with the cone of Bromo rising inside it and Semeru, Java’s highest peak, beyond.

Grass and scrub grow on the slopes and outer areas. In the dry season that vegetation cures to tinder, and the terrain — steep, loose underfoot, cut by ravines — makes ground access slow and dangerous.

Fires in such places are frequently fought on foot with hand tools and beaters, because water is not available at altitude and aircraft cannot operate safely in narrow, smoke-filled terrain.

What 550 hectares means

By the standards of Australian or Californian megafires, 550 hectares is small. In a protected volcanic park it is significant, because the ecosystems there are specialised and slow to recover, and because the park’s boundaries contain habitat that has nowhere to expand into.

The park is also a major destination for visitors, and fires close access — which affects the local communities whose livelihoods depend on that traffic.

Most fires in areas like this are started by people rather than by lava or lightning: cooking fires, cigarettes, agricultural burning that escapes. That is worth saying without accusation, because it means most of them are preventable.

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Source: Reuters, 10 August 2026.