After an 8.8-magnitude earthquake off the coast of Russia’s Kamchatka peninsula, early tsunami warning systems kicked in and helped millions of people safely evacuate

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

The 8.8 magnitude quake off Russia that triggered tsunami warnings across the Pacific occurred on what is known as a "megathrust fault", where the denser Pacific Plate is sliding underneath the lighter North American Plate.