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

An 8.8-magnitude earthquake struck off Russia’s eastern coast on late Wednesday morning, local time. The quake triggered tsunami waves across the Pacific that hit Russia, Japan, Canada and parts of the US coast.

Eyewitness video captured tsunami waves flooding the small Russian town of Severo-Kurilsk on Wednesday morning.