By VLADIMIR ISACHENKOV

MOSCOW (— A powerful earthquake struck Wednesday off Russia’s Far East coast, flooding a fishing port with waves from a tsunami, cutting power to a few areas and sending some panicked residents fleeing buildings but causing only a few injuries.

Regional authorities say they were prepared for the 8.8-magnitude quake and the subsequent waves, and moved quickly to keep residents safe. They introduced a state of emergency in some areas, but said there was no major damage.

Here is what to know about the Russian areas hit by the quake and tsunami:

Kamchatka peninsula

Dubbed the “land of fire and ice,” Kamchatka is one of the most active volcanic regions on Earth. It has about 300 volcanoes, with 29 of them still active, according to NASA’s Earth Observatory. Quakes and tsunamis regularly strike the peninsula that lies close to an ocean trench where two tectonic plates meet.

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The 1,200-kilometer (750-mile)-long peninsula nine time zones east of Moscow faces the Pacific Ocean on its east and the Sea of Okhotsk along its west coast. Kamchatka and a few nearby islands have a population of about 290,000 with about 162,000 of them living in the regional capital of Petropavlovsk-Kamchatsky in Avacha Bay on the peninsula’s southeast.

There are few roads on the peninsula, and helicopters are the only way to reach most areas. Fishing is the main economic activity. A major base for Russian nuclear submarines is located in Avacha Bay.

The tallest volcano is Klyuchevskaya Sopka (4,750 meters or 15,584 feet), the largest active volcano in the Northern Hemisphere. Observers heard explosions and saw streams of lava on its western slopes, according to the Kamchatka branch of the Russian Academy of Sciences’ geophysical service.

Scientists have anticipated the eruption for some time, with the volcano’s crater filling with lava for weeks and the mountain emitting plumes of ash. It last erupted in 2023.

The Kuril islands

The four volcanic islands, known in Russia as the Kurils, stretch between Kamchatka and the Japanese island of Hokkaido.

The islands were captured by the Soviet Union from Japan in the closing days of World War II. Japan asserts territorial rights to the islands it calls the Northern Territories, and the dispute has kept the countries from signing a peace treaty

The islands have a population of about 20,000, and the local economy is based on fishing. The Russian military has bolstered its presence in the area, refurbishing a Soviet-era air base and other outposts.

The impact of the quake and tsunami

The authorities on Kamchatka and the Kurils said they have been prepared for a major quake for a long time and acted quickly to protect the population.

The 8.8-magnitude quake, centered about 120 kilometers (75 miles from Petropavlovsk-Kamchatsky, struck at 11:24 a.m. local time (2324 GMT Tuesday, 7:24 p.m. EDT Tuesday) at a depth of about 21 kilometers (13 miles), according to the U.S. Geological Survey. Multiple aftershocks as strong as 6.9 magnitude followed.

The earthquake appeared to be the strongest on record since the 9.0 magnitude earthquake off northeastern Japan in March 2011 that caused a massive tsunami. Only a few stronger earthquakes have ever been measured anywhere.

Regional authorities on Kamchatka said several people were injured, but they didn’t elaborate. Regional health department chief Oleg Melnikov a few injuries occurred during evacuations, including a hospital patient injured while jumping out of a window. All were in satisfactory condition, he said.

Video from Russian media showed doctors on Kamchatka holding a patient and medical equipment as an operating room shook during surgery. The quake damaged a kindergarten in Petropavlovsk-Kamchatsky, but no children were in the building, which was closed for renovation. Municipal workers inspected about 600 apartment buildings and said no evacuations were needed.

Petropavlovsk-Kamchatsky was protected from big tsunami waves by its location on Avacha Bay. Emergency workers evacuated about 60 tourists from a beach of black volcanic sand on the Pacific side.

Tsunami waves could have been as high as 10 to 15 meters (30 to 50 feet) in some sections of the Kamchatka coast, Russia’s Oceanology Institute said, noting the biggest were under 6 meters (about 19 1/2 feet) near populated areas of the peninsula and the nearby Kuril islands.

Authorities in Severo-Kurilsk, the Kurils’ main city, evacuated residents from danger areas to deeper inland.

Severo-Kurilsk Mayor Alexander Ovsyannikov said tsunami waves flooded the fishing port along with a fish factory and swept fishing boats out to sea. Power was cut by the flooding, with authorities inspecting the damage.

Kremlin spokesman Dmitry Peskov noted the quake warnings were issued in a timely fashion, people were evacuated quickly, and buildings withstood the shocks.