The U.S. Geological Survey (USGS) has launched an investigation after it erroneously issued an alert for a significant 5.9 magnitude earthquake that never happened. The false report caused concern among residents in parts of the western United States early on Thursday morning.
Details of the Incorrect Seismic Alert
The alert was issued in the early hours of Thursday 4 December 2025. It indicated a powerful seismic event with a magnitude of 5.9 near the cities of Reno and Carson City in Nevada. The notification was disseminated through USGS data feeds and was received by residents across Nevada and into California shortly after 8 a.m. Pacific Time.
However, no such earthquake occurred. The USGS has confirmed the event was non-existent, stating clearly: "The event did not occur." The organisation has since removed all traces of the false alert from its official websites and public data streams.
Investigation and Response Underway
The focus has now shifted to understanding the origin of the error. The USGS has stated it is actively investigating the technical or procedural reason behind the generation and distribution of the incorrect report. Such false alerts, while rare, can trigger unnecessary public alarm and test emergency response protocols.
The incident highlights the critical importance of accuracy in seismic monitoring systems, especially in regions like the western U.S. which are prone to earthquakes. Residents rely on timely and correct information from authoritative bodies like the USGS for their safety.
Implications for Seismic Monitoring
While the USGS system is generally highly reliable, this event serves as a reminder of the potential for technical glitches. The investigation will likely examine the entire data pipeline, from sensor inputs to public notification systems, to prevent a repeat occurrence.
For now, the USGS has assured the public that the alert was a mistake and that no seismic activity of the reported scale took place. The organisation is expected to provide updates on its findings once the internal review is complete.
