Six volcanoes in far eastern Russia are now erupting following the 8.8 magnitude earthquake and aftershocks that shook the region last week.
Klyuchevskaya erupted first, on July 30. It had already shown signs of unrest before the earthquake, and experts deduced that the quake likely intensified the eruption but didn’t trigger it. However, it’s difficult to know the exact effect of the earthquake on the volcano. Eruptions of nearby volcanoes Shiveluch, Bezymianny, Karymsky, Avachinsky and Krasheninnikov soon followed and continue through today.
All of the volcanoes sit on the Ring of Fire, a geological feature notorious for volcanic and seismic activity.
The area around this parade of erupting volcanoes, called the Kamchatka Peninsula, is sparsely populated, so there doesn’t seem to be an active threat to local communities. However, the eruptions could pose a risk to planes if they were to fly through ash plumes, Harold Tobin, a seismologist at the University of Washington, told Live Science in an email.
Despite the recent spate of eruptions, experts say this kind of volcanic activity is not out of the ordinary. “About 40 to 50 volcanoes are actively erupting around the world at any given time. Right now is no different,” Tobin said. “Kamchatka is a very volcanically active region.”
Were the eruptions caused by the earthquake?
There is no clear or singular way an earthquake can cause volcanic eruptions, but these two events can co-occur at subduction zones, areas where one tectonic plate dives beneath another.
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“It is not unprecedented for a large subduction zone earthquake to trigger volcanic eruptions,” Paul Segall, a geophysicist at Stanford University, told Live Science in an email.
The largest earthquake ever recorded — a magnitude 9.5 quake that struck Valdivia, Chile, in 1960 — was followed by several volcanic eruptions. “The earthquake changed the stress in [Earth’s] crust, which may have made it easier for magma to rise to the surface,” Segall said. The shaking of the ground by the earthquake also may have contributed to the eruptions by changing the movement of magma beneath Earth’s surface.
Both these mechanisms could have played a role in the Chilean eruptions, but it’s still too soon to characterize the recent Russian events, Segall said.
Klyuchevskoy was already showing signs of activity prior to the earthquake, but “it did likely increase in the vigor of the eruption, including some ash emission,” a U.S. Geological Survey representative told Live Science on July 30.
The most notable aspect of this chain of events was the eruption of Krasheninnikov for the first time in about 500 years. “The timing is either a very strong coincidence or its magma system was perturbed by strong seismic waves and triggered the eruption,” Tobin explained. “It’s very hard to determine which is true for a single given eruption.”
Additionally, the Ministry of Emergency Situations of Russia for the Kamchatka Territory reported increased thermal activity of a seventh nearby volcano, Mutnovsky. Satellite images revealed a thermal anomaly at the volcano, which has yet to erupt, but scientists say they can’t predict if or when it might blow.