8.7 magnitude earthquake in Russia's Far East, tsunami warning issued. Fukushima nuclear power plant evacuated.

It's already being called the " strongest earthquake in decades ." But right now, the most concrete fear is the tsunami wave that has already hit the Pacific coasts, from Japan to Ecuador—so far without causing significant damage.

The magnitude 8.7 earthquake struck the Kamchatka Peninsula in Russia's Far East last night, triggering tsunami warnings, forcing evacuations, and causing damage. The U.S. Geological Survey reports that the earthquake was shallow, with a depth of 19.3 km, and its epicenter was about 125 km east-southeast of Petropavlovsk-Kamchatsky, a city of 165,000 along the coast of Avacha Bay.

In the following hours, a tsunami hit the coasts of the Russian Kuril Islands and the northern Japanese island of Hokkaido.

In Japan , the weather agency reported that an initial tsunami wave of about 30 centimeters (12 inches) reached Nemuro , on the eastern coast of Hokkaido, the northernmost of Japan's four major islands. The quake occurred about 250 kilometers (155 miles) from Hokkaido, where it was only slightly felt. All employees at the Fukushima nuclear power plant in northeastern Japan have been evacuated , the plant's operating company, Tepco, said, adding that "no anomalies were observed" at the site. The plant malfunctioned and caused a serious radioactive leak after being hit by a tsunami in 2011.

In Russia , the first tsunami wave hit the coastal area of Severo-Kurilsk , the main settlement on the Russian Kuril Islands in the Pacific. According to local governor Valery Limarenko, residents are safe and are staying on higher ground until the threat passes.

Tsunami warning sirens also sounded in Honolulu, Hawaii , and people were ordered to move to higher ground.

The Pacific Tsunami Warning Center had forecast the danger of waves 1 to 3 meters above tide along some coastal areas of Hawaii, Chile, Japan, and the Solomon Islands. Waves exceeding 3 meters are possible in some coastal areas of Russia and Ecuador.

The town of Severo-Kurilsk, in southern Kamchatka, has been evacuated , Sakhalin Governor Valery Limarenko said. The Russian news agency Tass reported that in the largest nearby city, Petropavlovsk-Kamchatsky, many people were out in the streets without shoes or clothing. Cabinets fell, mirrors broke, cars swayed in the streets, and building balconies shook noticeably. Tass also reported power outages and mobile phone network failures in Kamchatka's capital.

The U.S. Tsunami Warning System also issued a warning of "dangerous tsunami waves" within the next three hours along parts of Russia and Japan. The Alaska-based National Tsunami Warning Center issued a warning for parts of the Aleutian Islands and a warning for parts of the West Coast, including Alaska, California, Oregon, Washington, and Hawaii. A warning was also issued for the U.S. territory of Guam and several islands in Micronesia.

The American center claims that three-meter high waves could reach Ecuador , thousands of kilometers across the Pacific.

Kamchatka and the Russian Far East lie on the so-called Pacific “Ring of Fire,” a geologically active region prone to strong earthquakes and volcanic eruptions.

Kamchatka volcano eruption (iktor Frolov | Institute of Volcanology and Seismology of the Far Eastern Branch)

No injuries have been reported so far, but the evacuation of a small town in the Sakhalin region has been ordered, regional governors said.

"Today's earthquake was severe and the strongest in decades," Kamchatka Governor Vladimir Solodov said on Telegram. According to preliminary information, Solodov said, there were no injuries, but a kindergarten was damaged.

Sakhalin Governor Valery Limarenko also reported via Telegram that an evacuation order has been issued for the town of Severo-Kurilsk : approximately 2,500 inhabitants, it was already destroyed by a tsunami on November 5, 1952 and then rebuilt in a higher area.

Russia, Kamchatka volcano (Reuters/Roscomos)