What awaits Kamchatka: the epicenters of strong earthquakes on the peninsula in the future are named

A powerful earthquake in Kamchatka not only caused the peninsula to shift by almost two meters, but also activated several volcanoes, including Krasheninnikov, which had not erupted for more than 600 years. Scientists explain these processes by the movement of lithospheric plates in the subduction zone and warn of possible aftershocks and associated seismic risks. About the epicenter of strong earthquakes in Kamchatka in the future and what awaits the peninsula after a unique natural phenomenon — in the material of Izvestia.

Why did a mega earthquake happen in Kamchatka?

The main cause of strong earthquakes remains the movement of lithospheric plates, a fundamental geological process related to the Earth's internal heat and convection in the mantle, experts say. These processes occur regardless of climate, solar activity, or time of year.

And the Kamchatka region is one of the most seismically active on the planet. It is part of the Pacific Ring of Fire, within which about 90% of all earthquakes occur and more than 75% of Earth's active volcanoes are concentrated.

The main reason for the high seismic activity is that Kamchatka is located in a subduction zone (subduction. — Editor's note): The Pacific lithospheric oceanic plate is sinking under the continental plate at a rate of about 8 cm per year. In this process, tectonic stress accumulates, which is periodically released in the form of earthquakes, said Alexey Morozov, a leading researcher at the Laboratory of Seismic Hazard at the Institute of Physics and Technology of the Russian Academy of Sciences, Doctor of Technical Sciences, in a conversation with Izvestia.

Why has Kamchatka shifted by two meters

The southern part of the Kamchatka Peninsula shifted almost two meters to the southeast after the powerful earthquake on July 30 and decreased slightly in height, Danila Chebrov, director of the Kamchatka branch of the United Geophysical Service of the Russian Academy of Sciences, said in a conversation with Izvestia.

Experts pointed out that this displacement pattern corresponds to the preliminary model of movements in the hearth, where the maximum deformations occurred on the southern flank, which caused a strong macroseismic effect in Severo-Kurilsk.

According to Chebrov, the lithospheric plates of the peninsula are in motion all the time. It is noteworthy that such shifts that occur during earthquakes may not be noticed without accurate instruments. And we should not expect further serious consequences of such earthquakes.

"The shift is the result of a powerful earthquake. Therefore, nothing additional can happen there, except what will happen during the aftershock process. And the seismic process in Kamchatka did not stop by itself," he concluded.

At the same time, such shifts can have serious consequences for the infrastructure:

— the appearance of cracks, fractures, displacement of the coastline and riverbeds;

— damage to roads, bridges, pipelines, buildings, and other facilities.

Earthquake in Kamchatka triggered the "trigger mechanism" of volcanoes

The "awakening" from the centuries-old sleep of the Krasheninnikov volcano, which has not erupted for more than 600 years, could be due to the fact that Kamchatka is located in a subduction zone where lithospheric and magmatic processes closely interact.

At that time, the volcano's ash emissions reached a height of 3-4 km above sea level, and later this eruption was recognized as a unique and important event for volcanology. At the same time, other volcanoes in Kamchatka became active — Klyuchevsky, Bezymyanny, Kambalny, Karymsky, Mutnovsky and Avachinsky.

The eruption of the Klyuchevsky volcano became especially noticeable, which threw out a column of ash for 6 kilometers and lava, which spread for 3.5 kilometers towards the Bogdanovich glacier.

"Earthquakes can only provoke an eruption if the volcano was already in a state of magmatic preparation. That is, an impact can become a "trigger mechanism", but it is not an independent cause of volcanic activity," said Alexey Morozov.

What awaits Kamchatka after a strong earthquake

The last strong seismic activity in Kamchatka was among the six strongest earthquakes on our planet since the twentieth century. Experts predict that such earthquakes will occur in the future, but over long periods of time — several decades.

"The first days after an earthquake are the most dangerous, then the number and strength of aftershocks decrease. It is difficult to estimate the probability of strong tremors, but I think that earthquakes of magnitude greater than 7 are still possible," Egor Zelenin, head of the Laboratory of Neotectonics and Modern Geodynamics at the Geological Institute of the Russian Academy of Sciences, said in an interview with Izvestia.

He noted that the frequency and location of strong earthquakes are determined by processes on a planetary scale — the movement of lithospheric plates. These processes change extremely slowly, so there is no need to expect changes in seismicity in the foreseeable future.

Which areas of Kamchatka are vulnerable to future earthquakes

Despite the constant earthquakes on the peninsula, tremors with a magnitude above 7-8 occur much less frequently. And the most vulnerable areas of Kamchatka to strong earthquakes and accompanying tsunamis are areas located along the eastern coast of the peninsula, especially near the subduction zone, Morozov believes. It is in this area that the epicenters of the strongest earthquakes are located.

"Strong tremors can cause landslides, avalanches, changes in terrain, as well as damage to infrastructure in mountainous areas of central and southern Kamchatka," the seismologist believes.

In addition, the low-lying parts of the Petropavlovsk agglomeration and the village of Ust-Kamchatsk located significantly to the north are among the currently populated areas in the risk zone, said Egor Zelenin.

At the same time, there is currently no reliable scientific evidence that strong earthquakes may become more frequent globally in the future.