Late Wednesday night, a strong 8.2-magnitude earthquake off the southern coast of Alaska triggered a tsunami watch that extended as far as Hawaii and a tsunami warning for portions of the state. Within hours, the threat of a tsunami was eliminated, but seismologists reported that people in cities and towns sought shelter from the biggest earthquake to strike the US in 50 years.

According to the U.S. Geological Survey, the earthquake was discovered at approximately 10:15 p.m. local time, 75 miles southeast of Chignik, Alaska.

According to the Alaska Earthquake Center, it was felt on Kodiak Island and throughout the Alaska Peninsula.

As news of the tsunami warning spread, people in Kodiak started to evacuate to higher ground and schools, and tsunami sirens began to sound.

Serious damage was not immediately reported. However, the earthquake shook homes, lodges, campgrounds, and locals for miles around.

After a long day as a caretaker at Camp Woody, Questa Harper was relaxing in a rocking chair on Woody Island, a short boat ride from Kodiak.

She started to feel as though the chair was rocking sideways as she glided back and forth. On Thursday, she remarked, “I thought that was odd.”

Then, at the camp, where she and her husband work, cellphones began to display earthquake emergency notifications.

About 69 campers were gathered by staff members. The group filed out of buildings into the darkness, across the campus, and up a wooden stairway that led to a hill at a higher elevation, all while being led in song.

After that, the staff brought sleeping bags, water, fuel, and snacks. They dragged a generator into position. Trailers and four-wheelers were moved. They had to make due with the limited number of cabins on the hill.

She described the night as dry and warm. “Until we received the all-clear, we set up our sleeping bags on the hill.”

More than 400 miles from Kodiak, in Cold Bay, a fishing and waterfowl hunting destination, Michael Ashley was wrapping up his work as manager of the Cold Bay Lodge and getting ready to go to bed.

The floor appeared to swell under his feet at around ten o’clock in the evening.

On Thursday, Mr. Ashley, 21, remarked, “It rolled around and felt like I was going over a wave on a boat.” “It continued for a minimum of one minute.”

He built shelves for some of his most valuable items, including an assortment of old Japanese glass floats that were once used by fishermen to keep their nets and lines afloat and that frequently wash up on the beach to the delight of beachcombers. The discovery of one large float was especially recent.

According to him, there was no panic because the majority of the lodge’s patrons were at the bar at the time. “Earthquakes occur every year in the Aleutians,” he stated. “I left the building for the one last year. It was far more aggressive.

An earthquake with a magnitude of 6.4 occurred off the coast of a remote region of southern Alaska last December, but no tsunami warnings were issued, posing no threat to the region’s sparsely populated chain of islands.

Mr. Ashley was referring to the July 2020 earthquake, which occurred near Wednesday’s main earthquake activity and had a magnitude of 7.8. It occurred offshore, south of the Alaska Peninsula. In 2018, a magnitude 7 earthquake rocked Anchorage, causing bridges to buckle, roads to be damaged, and buildings to crack.

In Alaska, earthquakes are frequent. In 2020, the state and surrounding areas saw over 49,000 seismic events, according to the Alaska Earthquake Center. Additionally, according to the center, Alaska experienced the strongest and third-most powerful earthquakes globally last year.

Some of the biggest earthquakes in the world occur in the southern portion of Alaska, which stretches from Anchorage to the Aleutians. Stephen Holtkamp, a seismologist at the center, stated on Thursday that when the Pacific plate shifts northward, it clashes with the continental crust and “the plate dives beneath Alaska.”

According to him, the July earthquake that occurred just to the west most likely accelerated Wednesday’s earthquake. “Anytime there is an earthquake, there is a chance that there will be more earthquakes nearby, and it appears that’s what happened here,” he said. “There will be more stress on the nearby portions of the fault.”

However, he noted that because the Aleutians are sparsely populated and the earthquake occurred deep beneath the earth’s surface, it did not cause significant damage on Wednesday. Dr. Holtkamp stated, “You were still 30 kilometers away even if you were directly on top of it.”

According to U.S.G.S. data, the Wednesday earthquake was one of just 17 earthquakes of magnitude 8.2 or higher that have occurred worldwide since 1990.

The most powerful earthquake to ever strike North America was a 9.2-magnitude earthquake that occurred in 1964 in the south-central region of Alaska. For approximately four and a half minutes, the ground trembled violently across a large area. Over 125 people lost their lives, Anchorage suffered significant damage, and a large portion of the fledgling state’s infrastructure was destroyed.

The U.S.G.S. reported that at least two dozen aftershocks to the earthquake that struck Alaska on Wednesday were recorded. One of the biggest, located on the Alaska Peninsula approximately 70 miles southeast of Perryville, had a 6.1.

For roughly two hours, south Alaska, the Alaska Peninsula, and the Aleutian Islands were under the National Tsunami Warning Center’s alert.

Additionally, Gov. David Ige announced on Twitter that a tsunami watch had been temporarily issued for Hawaii and then canceled a little more than an hour later. The Beach, Hawaii, office of the National Weather Service had issued a warning that “widespread hazardous tsunami waves are possible.”

According to the Weather Service, major earthquakes beneath or close to the ocean floor are the most frequent cause of tsunamis, which are defined as a sequence of waves brought on by a significant or abrupt displacement of the ocean. The waves can travel across ocean basins and radiate outward from the disturbance in all directions.