A lava flow descending from the Klyuchevskoy volcano on Russia's Kamchatka Peninsula has reached three kilometres in length and is approaching the Bogdanovich glacier, which is actively melting, potentially endangering tourists on the nearby Tolbachik volcano, TASS reported on August 4.

Alexei Ozerov, director of the Institute of Volcanology and Seismology of the Russian Academy of Sciences Far East Branch, said the lava flow presents a dangerous phenomenon as it moves downward and could reach the glacier at its current speed.

"The glacier is now intensively melting. There is a probability that huge water flows and lahars will go along the Studyonaya River and may then wash away a section of the Kozyrevsk-Petropavlovsk-Kamchatsky highway," Ozerov told TASS.

He warned that a large number of tourists currently on the Tolbachik volcano could be trapped for some time by powerful waters from the Studyonaya River if this event occurs.

The Klyuchevskoy volcano is the highest active volcano in Eurasia, representing a perfect cone with a summit crater approximately 700 metres in diameter. About 80 subsidiary explosive craters and cinder cones are located on its slopes.

The volcano is situated 30 kilometres from the village of Klyuchi in the Ust-Kamchatsky district, which has approximately 4,500 residents. It began erupting in April 2025, with activity increasing following the July 30 earthquake that struck the region.

The warning highlights the ongoing volcanic hazards facing the Kamchatka Peninsula, where several active volcanoes pose risks to both local populations and the region's growing tourism industry.

The event is believed to be linked to the massive magnitude 8.8 earthquake that struck off the Pacific coast last week.

The eruption marks the first confirmed activity at Krasheninnikov in more than six centuries. Although the twin-peaked stratovolcano has long been recognised as dormant, no historical eruptions had ever been documented until now. The volcano, located in the eastern part of the peninsula, had been monitored in recent decades but showed no signs of imminent activity until the seismic event on July 29.

“The eruption column rose to 5–6km in height,” KVERT reported on August 2, adding that ash was drifting eastwards over uninhabited areas. A code orange aviation warning was issued, advising aircraft to avoid the region due to the risk of ash cloud interference with jet engines.

As bne IntelliNews reported, the melting icecaps could cause more, and more violent, earthquakes as the weight of the ice on tectonic plates eases make it easier for them to move.