A volcano in eastern Russia erupted for the first time in 475 years, prompting a tsunami warning. The Krasheninnikov volcano in Kamchatka became active days after one of the strongest earthquakes ever recorded hit the region.

A powerful earthquake that struck off the coast of Russia has generated tsunami warnings and advisories for a broad section of the Pacific, including Alaska, Hawaii and the U.S. West Coast

Russia’s magnitude 8.8 earthquake spawned serious tsunami warnings, but waves have been moderate so far. Here’s the geological reason why