A 7.8 magnitude earthquake has occured off the coast of Russia's Kamchatka Peninsula. "Based on preliminary earthquake parameters... hazardous tsunami waves are possible for coasts located within 300 km (186 miles) of the earthquake epicenter, the U.S. Pacific Tsunami Warning Center wrote in its official message.
Tsunami waves, however, were unlikely to reach Kamchatka's eastern coast, some 500 km (310 miles) away. The quake was followed by several aftershocks, including a couple above magnitude 5.0. The earthquake was originally reported as a 7.4 magnitude, but it was subsequently upgraded to 7.8.