Tsunami strike alert ⚠️in Alaska

 

7.3 Magnitude Earthquake Strikes Near Sand Point, Alaska, Triggering Tsunami Advisory

On Wednesday, July 16, 2025, a powerful 7.3 magnitude earthquake struck off the coast of Alaska, approximately 54 miles (87 kilometers) south of Sand Point, a small community on Popof Island in the Aleutian chain. The quake, which occurred at 12:37 p.m. local time (2037 GMT), prompted the National Tsunami Warning Center (NTWC) to issue a tsunami warning for a 700-mile stretch of Alaska’s southern coast, from Kennedy Entrance (40 miles southwest of Homer) to Unimak Pass (80 miles northeast of Unalaska). The warning was later downgraded to a tsunami advisory and canceled by 2:43 p.m. local time after a small tsunami wave, measuring just 0.2 feet (6.1 centimeters) above the tide, was observed at Sand Point.

Seismic Activity in a Volatile Region

Alaska, part of the seismically active Pacific Ring of Fire, is no stranger to earthquakes. The region’s tectonic activity is driven by the subduction of the Pacific Plate beneath the North American Plate along the Alaska-Aleutian Megathrust, a fault system stretching over 2,500 miles. This latest quake, at a shallow depth of 12.5 to 20.1 kilometers, had the potential to generate a significant tsunami, as shallow earthquakes often cause substantial seafloor displacement.

The earthquake was felt as far away as Anchorage, nearly 600 miles (966 kilometers) northeast of the epicenter, though the city was not at risk from the tsunami. Residents in affected areas, including Sand Point, Kodiak (population 5,200), and Cold Bay, reported moderate to strong shaking. In Sand Point, city administrator Debi Schmidt described the quake as the most intense she had ever experienced, with cupboard doors flying open and items falling, though no significant damage was reported.

Tsunami Response and Advisory Details

Following the earthquake, the NTWC issued an urgent tsunami warning, prompting emergency sirens in Kodiak and evacuation orders for residents in coastal areas to seek higher ground. Multiple buoys off Alaska’s coast entered “tsunami mode,” detecting changes in ocean waves indicative of a potential tsunami. However, the observed wave at Sand Point was minimal, and the warning was downgraded to an advisory within an hour. The advisory, covering South Alaska and the Alaska Peninsula, was lifted by 2:43 p.m. after data from the Deep-ocean Assessment and Reporting of Tsunamis (DART) buoys confirmed no significant tsunami threat.

The NTWC advised residents to remain cautious, warning against returning to coastal areas, including harbors, marinas, bays, and inlets, until local officials deemed it safe. No major tsunami waves were reported, and authorities confirmed no damage or injuries across the affected regions. The National Weather Service also clarified that there was no tsunami threat to other U.S. or Canadian Pacific coasts, including California, Oregon, Washington, or British Columbia.

Aftershocks and Ongoing Monitoring

The Alaska Earthquake Center reported approximately 30 aftershocks in the two hours following the main quake, with the largest reaching a magnitude of 5.2. Alaska’s southern coast has experienced five earthquakes exceeding magnitude 7 since 2020, underscoring the region’s high seismic activity. The 1964 Good Friday earthquake, a 9.2-magnitude event—the strongest ever recorded in North America—serves as a stark reminder of the region’s potential for catastrophic seismic events. That quake triggered a tsunami that caused widespread destruction and 122 fatalities.

Scientists note that factors like glacial melt and changing ocean currents may influence stress distribution on fault lines, potentially increasing the frequency of such events. The NTWC’s DART buoy network and rapid response systems demonstrated their effectiveness in this event, though experts caution that balancing speed and accuracy in tsunami warnings remains a challenge.

Community Impact and Preparedness

In Kodiak, emergency sirens prompted swift action, with residents moving to higher ground. In King Cove, a community of about 870 people, similar alerts were issued. While the tsunami threat subsided quickly, the event highlighted the importance of preparedness in Alaska’s earthquake-prone regions. The state’s history of seismic activity, including major quakes in 2021 and 2023 near Sand Point, reinforces the need for robust warning systems and community readiness.

This earthquake serves as a reminder of Alaska’s volatile geology and the critical role of modern monitoring systems in mitigating risks. As the region continues to experience frequent seismic activity, residents and authorities remain vigilant for future events.