Author: Huizhong Chen

The U.S. Geological Survey (USGS) issued a warning on March 4th about a 5.9 magnitude earthquake in Nevada, but later withdrew the warning, stating it was a false alarm.

Earlier that day, the USGS's Shake Alert system issued a warning that a 5.9 magnitude earthquake had occurred at 4:06 PM GMT on March 4th, 6 kilometers east of Dayton, Nevada.

The earthquake alarm immediately alarmed the public, but the USGS quickly realized it was a false alarm; no earthquake had occurred. The USGS withdrew the warning and announced an investigation into the cause of the false alarm, promising to release updates to the public.

A geophysicist at the USGS stated that this may be the first time the agency has issued a completely false earthquake warning.

The epicenter of the false alarm was located approximately 19 kilometers northeast of Carson City, the capital of Nevada. Law enforcement agencies in several towns in the area confirmed that they did not feel any tremors and found no other signs of an earthquake.

Why do earthquake warnings sometimes go wrong? There are likely two reasons for this. First, the earthquake early warning system may have malfunctioned, a situation that has occurred in Japan and my country. Earthquake early warning systems are 24/7, continuous earthquake observation and large-scale computer processing systems that cannot be interrupted for even a second. They are highly reliable systems, arguably the most demanding operating systems in the world. Since humans cannot yet accurately predict earthquakes, earthquake early warning systems act like sleepless guardians, constantly protecting human safety. To achieve this, the system is extremely complex to ensure uninterrupted operation.

However, no system is immune to problems. This false alarm from the US earthquake early warning system is the first such incident since Shake Alarm began operation.

The second reason could be system interference. The earthquake early warning network in the western United States includes thousands of seismic observation stations, while my country's earthquake early warning network has approximately 20,000 stations. With such a massive scale, the main sources of interference are electromagnetic waves and lightning strikes. Secondly, disturbances caused by humans, animals, sudden tornadoes, landslides, and especially human or animal activity near earthquake zones, as well as vibrations from vehicles driving near seismic stations, can trigger seismographs at seismic stations, leading to misidentification as earthquakes.

Besides these two problems, current earthquake early warning systems also have the issue of mistaking small earthquakes for large ones, and vice versa.

Some people ask, "Then should we still trust earthquake warnings?" The answer is absolutely yes. First, such problems are extremely rare.

Second, regarding all warnings, including air raid sirens, typhoon warnings, heavy rain warnings, geological disaster warnings, and of course, earthquake warnings, we should adopt a "safety first, regret later" strategy. This means taking immediate evacuation action upon receiving the warning, even if it's a false alarm and we've wasted our time. But if it is real, we can escape disaster!