Russia earthquake: Magnitude 8.8 megaquake hits Kamchatka, generating tsunamis across the Pacific

Tsunami warnings have been issued in regions across the Pacific, including Hawaii, Alaska, Russia and Japan, following a magnitude 8.8 "megaquake" — the joint-sixth largest ever recorded — that hit off Russia's Far Eastern Kamchatka Peninsula at 11:25 a.m. local time (18:25 p.m. EST) on Wednesday morning (July 30), according to the U.S. Geological Survey (USGS).

Tsunami waves could reach higher than 10 feet (3 meters) above tide level along the coasts of Hawaii, Ecuador and Russia, according to a warning issued by the U.S. National Tsunami Warning Center at 11:07 p.m. EST on July 29. The first waves reached Hawaii, with a 4 foot (1.2 m) wall of water recorded by the Pacific Tsunami Warning Center (PTWC) off the coast of Oahu, the BBC reports.

"A tsunami has been generated that could cause damage along coastlines of all islands in the state of Hawaii," the PTWC said in a bulletin. "Urgent action should be taken to protect lives and property."

Honolulu's mayor Rick Blangiardi warned residents to move to higher ground and Hawaii's governor, Josh Green, urged people to immediately evacuate coastal regions.

In a news conference reported by CNN, Green said "it will not hit one beach, it will wrap around the islands."

In Japan, officials have told more than 1.9 million people to evacuate as waves measuring over 4 feet (1.2 m) hit the country's north and east coasts, CNN reports.

Footage of tsunami waves hitting the Russian coastal town of Severo-Kurilsk in Kamchatka, shows water flooding buildings on the port.

In North America, tsunami advisories are also in place along the coasts of California, Oregon, Washington, British Columbia, Alaska and the Aleutian Islands. Waves measuring between 3 and 10 feet (1 to 3 m) are also possible along the coasts of Chile, Costa Rica, French Polynesia, Japan, Jarvis Island, Johnston Atoll, Kiribati, Midway Island, Palmyra Island, Peru, Samoa and the Solomon Islands, according to the PTWC.

The epicenter of the earthquake was recorded roughly 74 miles (119 kilometers) southeast of Petropavlovsk-Kamchatsky, on the Kamchatka Peninsula, according to the USGS. As of midnight EST, 24 powerful aftershocks reaching magnitudes of over 5.0 were reported in Russia, with two hitting magnitudes of 6.9 and 6.3, respectively.

The Kamchatka earthquake is considered a megaquake as its magnitude is above 8.

The Kamchatka Peninsula is a sparsely populated region located within the Pacific Ring of Fire, a horseshoe-shaped belt of volcanoes known for their explosive volcanic eruptions and intense earthquakes. The ring runs from southern Chile, up the west coast of the Americas, through the islands off Alaska and far eastern Russia and down through Japan and the Philippines.

The volcanoes here arise due to tectonic plates involved in a process called subduction. This movement lowers the melting point of rocks in Earth's mantle, creating pockets of magma that rise to the surface. "What's special about the Ring of Fire is that multiple oceanic plates in the Pacific have subduction boundaries there," Loÿc Vanderkluysen, a volcanologist at Drexel University in Philadelphia, previously told Live Science.

Indeed, it's estimated that 90% of the 34,000 miles (55,000 km) of subduction plate boundaries on Earth are found in the Pacific.

Tectonic movements also trigger earthquakes as the plates squeeze past each other. "There's lots of kicking and screaming as the plates grind against one another," Jeffrey Karson, a professor emeritus of tectonics at Syracuse University in New York, previously told Live Science. "And so that's where the biggest earthquakes on our planet take place."

Due to all this activity, the Ring of Fire is home to about 75% of Earth's active volcanoes and reports 90% of all measured earthquakes.

Indeed, the five largest earthquakes ever recorded have all taken place within this region:

1. Valdivia Earthquake, Chile: magnitude 9.5, 1960

2. Great Alaska Earthquake, U.S.: magnitude 9.2, 1964

3. Sumatra-Andaman Islands Earthquake: magnitude 9.1, 2004

4. Tohoku Earthquake, Japan: magnitude 9.1, 2011

5. Kamchatka Earthquake, Russia: magnitude 9.0, 1952

This latest earthquake comes in joint-sixth place with Chile's Maule Earthquake in 2010 and the Ecuador-Colombia Earthquake in 1906, all with a magnitude 8.8.