SAN FRANCISCO (AP) — Northern California experienced a rare and brief tsunami warning alert on Thursday following a 7.0 magnitude earthquake that shook part of the state. The National Weather Service swiftly canceled the alert after approximately an hour, well before the anticipated arrival time of the tsunami. During this period, some cities and counties initiated evacuations, while others utilized social media and text messages to disseminate the warning information. Individuals responded by either moving to higher ground or heading to the beach to witness the event.
People turned to social media to seek clarification on why the warning was issued and subsequently rescinded so rapidly, as well as to understand the criteria used by the NWS to issue alerts. A tsunami, derived from Japanese characters meaning harbor and wave, is a series of long waves triggered by an earthquake-induced movement of the ocean floor, as explained by the National Weather Service.
California has encountered over 150 tsunamis since 1800, with most being minor incidents, according to the California Geological Survey. The alert was issued shortly after an earthquake struck west of Ferndale in Humboldt County, prompting urgent notifications urging individuals to move away from coastal waters to higher ground or inland.
The NWS Bay Area acknowledged the rarity of tsunami alerts in the region and addressed the confusion and frustration stemming from Thursday's event. Warning alerts are the most severe of the four tsunami alerts, with the last one issued in 2011 following an earthquake in Japan that caused significant damage along the California coast.
Thursday's earthquake, being local and near the coast, necessitated a rapid high-level alert to provide maximum preparation time due to the swift movement of tsunami waves. Scientists monitored buoys and earthquake data during this time, ultimately canceling the alert upon observing minimal sea-level changes and determining the earthquake's characteristics made it less likely to generate a tsunami.
Response efforts varied across Northern California, with authorities in Eureka conducting evacuations in high-risk areas and San Francisco issuing alerts to stay away from water bodies. Emergency personnel in various cities took proactive measures to ensure public safety, with some areas opting not to sound tsunami warning sirens to prevent unnecessary panic.
Overall, the incident served as a test of emergency notification systems and highlighted the importance of preparedness and swift response in the face of natural disasters.
