Anomalous glow: after an earthquake in Kamchatka, a volcano that had been “sleeping” for 34 years awakens

Volcanic magmatic activity seems to be waking up at one of the quietest Kamchatka volcanoes after a series of earthquakes that occurred in the region from July 22 to July 30, 2025. We are talking about the Avichinsky volcano, which is located 120 kilometers from the epicenter of the earthquake. The last eruption of this volcano was recorded in 1991. We talked about the volcanic situation in Kamchatka with Skoltech professor, doctor of geological and mineralogical sciences, corresponding member of the Russian Academy of Sciences Ivan Kulakov.

Let us recall that on July 22, a series of powerful earthquakes occurred off the coast of Kamchatka. The strongest earthquake in the last 73 years was the one on July 30 with its epicenter in Avacha Bay. Despite the fact that the epicenter of the earthquake was in the Pacific Ocean, at a depth of 17 kilometers and more than 100 kilometers from the coast, the tremors were felt throughout the entire peninsula.

Two days later, information appeared that the Klyuchevskoy volcano had awakened from the earthquake, and its lava, which was flowing down the southwestern slope, was heading straight towards the largest Bogdanovich glacier.

According to the press service of the Kamchatka Volcanoes Nature Park, the eruption of Klyuchevskoy volcano may lead to the melting of this, one of the largest glaciers on the peninsula. According to volcanologists, the lava flow, the length of which has reached one and a half kilometers, is descending along the southwestern slope of the volcano and moving towards the glacier. Its melting, according to experts, may provoke the appearance of powerful mud flows in the bed of the Studenaya River.

Some experts have linked the eruption to the earthquake of July 30, and also suggested that during the melting of the glacier, so-called phreatic explosions (explosive evaporation of water) could occur on its surface, with the release of matter to a great height, up to several kilometers.

We turned to volcanologist Ivan Kulakov for comment.

- Ivan Yuryevich, explain, was it really the earthquake that caused the activation of Klyuchevskoy?

– This volcano was active before the earthquake, so it probably shouldn’t be associated with the seismic event of recent days.

– What is the threat of melting a glacier if lava reaches it?

The movement of the fiery mass over snow and ice forms so-called lahars — mudflows that rapidly move down the slope. The largest lahars were formed in 1985 in Colombia, during the eruption of the Nevado del Ruiz volcano. It was a powerful mudflow that traveled through the volcano valleys for more than 70 kilometers and destroyed an entire city. As for the Klyuchevskoy volcano, lahars can also form from it, but they will most likely not reach populated areas, since they are located at a large distance from the volcanic valley and glacier.

Lava flows on a glacier are interesting in themselves. For example, not long ago my colleague Alexander Belousov, who studied the effect of lava flows on snow, discovered that lava heated to 1000 degrees does not always cause snow to melt. It turns out that there are cases when lava that penetrates under a snowfield can flow both under the snow and on the snow.

- How is this possible?

- It can melt it, but not completely. The thing is that above the lava flows that flow under the snow, a so-called gas cushion appears, which does not allow the upper flows to melt the snow. It turns out to be something like a layered pie of ice and fire.

- Now let's move on to phreatic explosions. Are they possible given the current events at Klyuchevskoy?

– I would not call possible small pops of gas escaping to the surface classic phreatic explosions. Phreatic is the type of eruption of the volcano itself, in which hot magma comes into contact with a large amount of external ice or water inside its volcanic system. When cold water begins to interact with magma, at this moment lightning-fast evaporation occurs, leading to a thermal explosion, in which rocks, ash and even so-called lava bombs are ejected.

There are places where such eruptions occur frequently, for example, the Kambalny volcano in the south of Kamchatka. Phreatic eruptions produce huge amounts of ash, and this can be dangerous for aviation. My research team and I have been caught in such "clouds" more than once. For those on the ground, it resembles a rain of wet gravel.

The term "phreatic explosions" is not suitable for the case of Klyuchevskoy, where a classic lava eruption occurs. Lava from it can creep onto a snowfield and begin to melt it, the same steam cushions are formed, which can break through and form small explosions on the surface, but this does not compare to a phreatic eruption of a volcano.

Awakening of the volcano

Much more interesting in light of the recent events related to the earthquake in Kamchatka, according to Kulakov, is another volcano – Avachinsky. It is quieter – the last magmatic eruption in it was in 1991, and after that only short-term activation without lava emission was observed. And now, after the July seismic event, Avachinsky reminded us of itself with an abnormal, at first glance, glow.

- What caused this glow?

- Because of the high temperature. Fumaroles are cracks in the earth's crust through which hot gases and steam escape, they form in areas of volcanic activity, where magma heats underground waters, turning them into steam. Their temperature reaches 800 degrees, and if there are many such gases, then the rocks heat up and a glow appears. It was noticed above the Avachinsky volcano by employees of the Kamchatka Geophysical Service and they reported this on August 1.

– Has Avachinsky become active because of the earthquake?

- There is a connection here. Especially since it is closer to the epicenter of the earthquake, 120 kilometers away, Klyuchevskoy is much further.