🌊 Major 7.3 Magnitude Earthquake Strikes Off Alaska Peninsula

🌊 Major 7.3 Magnitude Earthquake Strikes Off Alaska Peninsula 

When & where: On July 16, 2025, around 12:37 p.m. AKDT, a magnitude 7.3 earthquake occurred about 55 miles south of Sand Point, Alaska, in the Alaska Peninsula and Aleutian Islands region (The Daily Beast, Alaska Earthquake Center).

Depth & intensity: Approximately 9–12 miles deep, the quake was felt strongly in Sand Point and lightly in Anchorage and Juneau (Alaska Earthquake Center).

Aftershocks: Nearly 40 aftershocks occurred within hours, some above magnitude 5, per the Alaska Earthquake Center (Alaska Earthquake Center).

🚨 Tsunami Warning & Advisory 

Initial warning: The National Tsunami Warning Center and National Weather Service issued a tsunami warning for coastal areas from Kennedy Entrance through Unimak Pass, including Kodiak and Cold Bay, urging residents to reach high ground (Diario AS).

Downgrade to advisory: About an hour later, officials downgraded the warning to an advisory, then canceled it around 2:43 p.m. AKDT after confirming the threat had passed (Alaska Public Media).

📏 Tsunami Observations 

A small tsunami wave measuring 0.2 feet (~7 cm) was recorded at Sand Point by buoy sensors (The Daily Beast).

No damaging waves or flooding; the incident was defined as a modest local sea-level fluctuation (Alaska Public Media).

🏘 Impact on Communities 

Sand Point: Minor shaking knocked items off shelves; no structural damage reported (Alaska Earthquake Center).

Kodiak & Cold Bay: Tsunami sirens activated; residents moved to higher ground or to designated shelters; no damage noted (ABC News).

Broader region: Residents across the southern coast, including in Homer, King Cove, Unalaska, and Seward, responded to initial alerts but saw minimal tangible effects (Anchorage Daily News).

🌍 Geological Context 

This event is part of a cluster of powerful earthquakes (≥M7) in recent years, stemming from the active Aleutian Trench subduction zone .

Historical events include the devastating 1964 Great Alaska Earthquake (M9.2) and localized megatsunamis like the 1958 Lituya Bay wave (Wikipedia).

✅ Safety Takeaways Action Why it Matters Always heed tsunami warnings Even small events can escalate or become dangerous. Move quickly to high ground Coastal Alaska experiences "near-field" tsunamis—minutes matter (Diario AS). Expect aftershocks A 5 + quake could follow; have a plan and supplies ready. Officials have proven protocols Warnings were accurate and communities responded effectively. 

Tsunami advisory canceled after magnitude 7.3 earthquake

This video highlights the advisory process—from warning, to downgraded advisory, to cancellation—showing NOAA and NWS experts evaluating tsunami data.

📝 Summary 

The July 16, 2025 M7.3 quake near Sand Point triggered swift, coordinated responses from warning systems and local communities. Though the resulting tsunami was negligible (about 7 cm), the event served as a powerful reminder of Alaska's seismic volatility. Coastal residents in active seismic zones should maintain readiness: know evacuation routes, monitor official channels, and treat each quake seriously, no matter how small it seems.

Stay informed with local alerts and understand earthquake/tsunami protocols—knowing the signs can save lives.

The Daily Beast Diario AS San Francisco Chronicle