VLADIVOSTOK — The simultaneous activity of six volcanoes on Russia's Kamchatka Peninsula is a highly unusual phenomenon, which scientists are calling a parade of eruptions, TASS news agency reported.

"According to our data, the last time such widespread volcanic activity occurred in Kamchatka was in 1737, following a magnitude-9 earthquake," Alexey Ozerov, director of the Institute of Volcanology and Seismology, Russian Academy of Sciences, was quoted by TASS as saying.

Ozerov said the powerful seismic event on Wednesday may have reawakened the region's "sleeping giants".

Yury Demyanchuk, head of the volcanology station in the village of Klyuchi, said he had not seen such widespread volcanic activity in his five decades of work in Kamchatka.

"On Krasheninnikov volcano, both summit and central eruptions have begun simultaneously, which may indicate intense internal seismic processes. As for Kambalny volcano, I last worked on it in 1979. While it has been quiet for decades, it should not be considered extinct," Demyanchuk said.

He said the previous eruption of Krasheninnikov likely occurred in the 15th century and is known only from layers of volcanic ash.

As of Sunday, six volcanoes are showing active signs: Avachinsky, Klyuchevskoy, Bezymianny, Kambalny, Karymsky, and, most recently, Krasheninnikov, which is located in the Kronotsky Nature Reserve.

At Klyuchevskoy volcano, summit eruptions have intensified, accompanied by Strombolian activity, which refers to a type of eruption characterized by intermittent explosive bursts of lava.

Authorities are warning residents and visitors to stay away from the active volcanoes.

XINHUA