A Sudden Jolt Shakes Alaska

On Wednesday, July 16, 2025, at approximately 12:38 p.m. local time (4:38 p.m. ET), a powerful 7.3-magnitude earthquake struck off the southern coast of Alaska, sending shockwaves through communities and triggering a tsunami warning that sent thousands of residents scrambling to higher ground. The epicenter, located in the Pacific Ocean just south of the Alaska Peninsula near the Shumagin Islands, approximately 54 miles southeast of Sand Point, unleashed seismic energy that reverberated across a vast stretch of southwestern Alaska, from Kennedy Entrance near Homer to Unimak Pass near Unalaska. The U.S. Geological Survey (USGS) reported the quake at a shallow depth of about 9 miles (15 km), a characteristic that heightened its potential to generate a tsunami.

As sirens wailed and emergency alerts lit up phones, panic gripped coastal communities. The National Tsunami Warning Center, part of the National Oceanic and Atmospheric Administration (NOAA), issued an immediate tsunami warning for a 700-mile stretch of Alaska’s southern coast, including Kodiak Island, the Alaska Peninsula, and parts of the eastern Aleutian Islands. Residents were urged to evacuate low-lying areas and seek higher ground, with officials warning of potential tsunami impacts that could arrive within minutes. The urgency of the situation was palpable, as captured in a video shared on X by a Seward resident who had recently returned to Alaska after 25 years, only to find herself fleeing a potential tsunami. “Just pray we don’t get waved,” she said nervously, as she and others briskly moved away from the coast.

Chaos and Evacuation: Communities Respond

The earthquake’s impact was felt as far away as Anchorage, nearly 600 miles northeast, though the most intense shaking occurred in southern Alaska, particularly near the Aleutian subduction zone, a geologically active region notorious for seismic activity. In coastal towns like Homer, Sand Point, King Cove, and Unalaska, residents faced chaotic scenes of bumper-to-bumper traffic as they rushed to evacuate. Rachel Lord, the mayor of Homer, described the initial frenzy, noting, “We’ve been hearing [that] there was a lot of bumper-to-bumper traffic and people just trying to get off the spit.” In King Cove, a small fishing community of about 870 residents, local officials issued urgent alerts instructing those in low-lying areas to move to higher ground immediately.

Kodiak, a larger community with a population of around 5,200, was among the hardest hit by the tsunami warning. The U.S. Coast Guard evacuated personnel from its Kodiak base to higher ground and prepared air crews to assist if needed. Emergency shelters were opened at Kodiak High School and North Star Elementary School, providing refuge for those fleeing coastal areas. In Unalaska, a fishing hub of about 4,100 residents, officials advised people to move at least 50 feet above sea level or a mile inland. The rapid response was critical, as tsunamis can strike within minutes of a shallow marine earthquake, leaving little time for hesitation.

Tourists, too, were caught in the chaos. In Seward, Jodie Stevens and her husband, Aaron Park, were visiting the Alaska SeaLife Center when they heard shouts about the earthquake and the need to evacuate. Accompanied by a staff member urging passersby to move uphill, they walked several blocks in the rain to reach a designated safe zone. Stevens later recounted hearing a siren signaling the all-clear, a moment of relief after the tense evacuation. “I’m just thankful that the system seemed to warn us pretty well in advance,” she said.

A Tsunami Threat Downgraded

The National Tsunami Warning Center initially confirmed that a tsunami had been generated, with small waves raising sea levels by about 10 centimeters in some areas. However, the threat was less severe than feared. Roughly 90 minutes after the quake, at around 2:00 p.m. local time, the warning was downgraded to a tsunami advisory, and by 12:45 p.m. local time (6:45 p.m. ET), it was canceled entirely. The Tsunami Warning Center noted, “A tsunami was generated by this event, but it no longer poses a threat. Some areas may continue to see minor sea level changes.” Residents were cautioned to remain vigilant, as unusual waves could persist for up to 24 hours.

The relatively minor tsunami impact was a stroke of luck, according to experts. Michael West, a seismologist with the Alaska Earthquake Center, told Fox Weather, “Early signs suggest we’re on the lucky side today.” He emphasized that Alaska’s southern coast is a “gigantic earthquake zone,” where four out of five U.S. earthquakes occur. While earthquakes are common in the region, many are too small to be felt, and quakes of this magnitude—7.3—are rare. The last comparable event in the area was a 7.2-magnitude quake near the Andreanof Islands in 1996.

The Alaska Earthquake Center recorded more than 20 aftershocks within hours of the main quake, with the strongest measuring 5.2 in magnitude. These aftershocks, while unnerving, did not trigger additional tsunami warnings. West noted that the region’s seismic activity is driven by the Aleutian subduction zone, where the Pacific Plate is forced beneath the North American Plate, creating a volatile environment prone to significant earthquakes. The 1964 Great Alaska Earthquake, a 9.2-magnitude event that remains the most powerful in U.S. history, serves as a stark reminder of the region’s potential for catastrophic seismic events. That quake generated devastating tsunamis that caused widespread damage across Alaska, Hawaii, and even Japan.

A Region on Edge: Alaska’s Seismic History

Alaska’s location along the Pacific Ring of Fire makes it one of the most seismically active regions in the world. The Aleutian subduction zone, where Wednesday’s quake occurred, has produced several major earthquakes in recent decades, including a 9.1-magnitude quake in 1957, an 8.7-magnitude quake in 1965, and an 8.0-magnitude quake in 1986. These events highlight the region’s vulnerability to both earthquakes and tsunamis. The 1964 Great Alaska Earthquake, centered near Prince William Sound, not only caused widespread destruction but also triggered landslides in coastal fjords, generating localized tsunamis that devastated communities like Valdez.

The USGS explains that tsunamis are typically caused by shallow marine earthquakes that displace the seafloor, particularly thrust earthquakes, which involve vertical movement. While Wednesday’s quake was significant, its strike-slip nature—where tectonic plates slide past one another horizontally—reduced the likelihood of a major tsunami. However, even strike-slip quakes can generate small tsunamis, as seen in this event. The NOAA’s Pacific Tsunami Warning Center notes that earthquakes between 6.5 and 7.5 in magnitude, like this one, rarely produce destructive tsunamis, but small sea level changes near the epicenter are possible.

The rapid response of Alaska’s tsunami warning system was a testament to lessons learned from past disasters. The 1964 quake, which killed over 100 people and caused millions in damages, underscored the need for robust early warning systems. Today’s systems, including USGS’s ShakeAlert and NOAA’s Tsunami Warning Centers, provide critical seconds or minutes of advance notice, allowing communities to evacuate before shaking or waves arrive. In this case, the system worked effectively, with no major injuries or damage reported. In Sand Point, about 50 miles from the epicenter, Police Chief Benjamin Allen noted minor incidents, such as items falling off shelves, but no significant structural damage.

A Global Ripple Effect

Remarkably, the earthquake’s seismic waves were detected far beyond Alaska. Sensitive instruments recorded the quake’s energy as far east as the U.S. East Coast and across the ocean in Europe, Asia, and parts of Africa. While these vibrations were too weak to be felt by people, they highlighted the global reach of such a powerful event. Real-time computer simulations, as reported by the Daily Mail, converted seismic data into animations, showing a yellow star marking the epicenter and red lines tracing the expanding wavefronts from Alaska across the globe. Between 1.97 and 15.74 seconds after the quake, the waves primarily impacted western North America, reaching seismic stations in Alaska and the Pacific Northwest. By 39.36 to 64.94 seconds, they had spread to the East Coast and beyond.

Adding to the intrigue, scientists detected a massive magnetic pulse at the exact moment the earthquake struck, followed by a G1-class geomagnetic storm hours later. While the connection between earthquakes and geomagnetic activity is not fully understood, the coincidence raised questions among researchers about whether the quake could have influenced the Earth’s magnetic environment. This phenomenon, though rare, has been observed in past events, such as a 7.3-magnitude quake in California in 1992, which triggered seismic activity up to 750 miles away.

Community Resilience and Lessons Learned

The swift cancellation of the tsunami warning brought relief to Alaska’s coastal communities, but the event served as a stark reminder of the region’s vulnerability. Residents like the Seward woman who shared her experience on X expressed a mix of fear and gratitude. “I just got back to Alaska after 25 years, and now I’m running from a tsunami,” she said, her video capturing the urgency of the moment. The lack of significant damage or injuries was a fortunate outcome, but experts like West cautioned that aftershocks could continue for days or weeks, potentially reaching magnitudes of 6.0 or higher.

The earthquake also highlighted the importance of preparedness. Alaska’s emergency management systems, informed by decades of seismic activity, performed admirably. Jeremy Zidek, a spokesperson for Alaska’s emergency management division, emphasized the importance of treating every warning seriously, noting that communities activated their evacuation procedures promptly. The state’s history of devastating quakes, particularly the 1964 event, has fostered a culture of readiness, with residents trained to move to higher ground or inland at the first sign of a tsunami threat.

For comparison, recent events in other regions underscore the global risk of tsunamis. In May 2025, a 7.4-magnitude earthquake off Chile’s southern coast prompted evacuations in Chile and Argentina, with no major damage reported. In January 2024, a 7.6-magnitude quake in Japan triggered a tsunami that killed 48 people and devastated coastal towns. These incidents highlight the unpredictable nature of tsunamis and the critical need for rapid response systems.

Looking Ahead: A Region on Alert

As Alaska recovers from the July 16 quake, scientists and officials continue to monitor aftershocks and assess the region’s seismic risks. The Cascadia Subduction Zone, a nearby fault capable of producing a magnitude-9.0 earthquake, remains a major concern. A 2025 study warned that a megaquake along this fault could trigger a 100-foot tsunami, devastating the Pacific Northwest. The last such event, in 1700, destroyed entire villages, and experts estimate a 37% chance of a similar quake by 2100.

For now, Alaska’s coastal communities are breathing a sigh of relief, but the earthquake serves as a wake-up call. “We’re unprepared,” said Robert Ezelle, director of Washington state’s emergency management division, in a recent interview about the broader Pacific Northwest’s seismic risks. The July 16 event, while less destructive than feared, underscores the need for continued investment in early warning systems, public education, and infrastructure resilience.

As the sun set on July 16, 2025, residents of Sand Point, Kodiak, and Homer returned to their homes, grateful for the all-clear but mindful of the power of the earth beneath their feet. The 7.3-magnitude quake, with its brief but intense tsunami threat, was a reminder that in Alaska, nature’s beauty is matched only by its unpredictability.