Recent earthquakes have shaken regions from California to Venezuela and Japan, prompting millions to receive alerts on their phones. These notifications offered crucial moments for individuals to take cover.
In Venezuela, two significant earthquakes struck the country around Wednesday night and Thursday morning, while Japan’s northern coast also felt tremors. Earlier this week, Californians dealt with a moderate earthquake, and the Philippines experienced a tragic quake near Mindanao that claimed 37 lives earlier this month.
While various countries have established warning systems that notify people seconds before seismic activity begins, places like Venezuela can still access Google’s Android Earthquake Alerts for notifications.
Global Alarm Systems for Earthquakes
The U.S. Geological Survey reports that several nations have implemented earthquake early warning systems, including the United States, Mexico, Japan, Turkey, Romania, China, Italy, and Taiwan. Unfortunately, Venezuela lacks a national early warning system, with recent earthquakes, measuring 7.2 and 7.5 magnitudes, marking some of the most significant in over a century.
Nevertheless, certain residents in Venezuela did receive alerts through Google’s Android system, sometimes seconds or even minutes prior to the quakes.
This warning mechanism functions by using crowdsourced data from cell phone sensors to detect seismic activity and sends alerts to other nearby users. Richard Allen from the Berkeley Earthquake Institute shared that the reach of these alerts has vastly grown from 250 million people receiving notifications in 2020 to over 2.5 billion now.
Each month, Allen’s system dispatches approximately 60 alerts to about 18 million mobile devices.
One Venezuelan writer, Pericles Sánchez, who lives in Caracas, received an alert minutes before an earthquake struck, allowing him to evacuate his home, which fortunately sustained no damage.
“I only started to feel it once I was outside,” Sánchez noted.
Diogenes López, a 36-year-old Venezuelan now residing in Bogotá, Colombia, had an earthquake warning pop up on his app regarding his hometown. Having lived in Chile before, where similar systems are commonplace, he quickly checked the map and was alarmed to find the epicenter close to his family back home.
“I immediately thought of the worst-case scenario,” he admitted. “My whole family is there.” They later managed to confirm their safety through messages.
He added, “Venezuela lacks the seismic preparedness seen in places like Chile or Japan. Many people don’t know how to respond in these situations, and the older buildings in Venezuela worry me.”
Emerging Earthquake Warning Technologies
The U.S. West Coast has the ShakeAlert system, operated by the USGS, which covers California, Oregon, and Washington, providing alerts through various platforms, including the state-managed MyShake app. Since its initiation in 2019, it has sent out alerts for 194 earthquakes, totaling 6.8 million notifications.
Robert de Groot, a scientist at the USGS, shared that over 4 million people received alerts for the recent earthquakes.
“Having multiple alert methods is always beneficial. It’s akin to keeping a spare tire in your vehicle,” he stated.
Mexico pioneered the first public earthquake early warning system back in 1991, which now notifies citizens via broadcast networks, apps, and public alerts. Moreover, inhabitants of Mexico City participate in earthquake drills to prepare for possible occurrences.
In light of the catastrophic events following the 2011 magnitude 9.0 earthquake and tsunami, which devastated many lives and caused the Fukushima Daiichi nuclear disaster, Japan has strengthened its earthquake warning infrastructure to include ocean floor monitoring.
The Japan Earthquake and Tsunami Seafloor Observation Network utilizes extensive underwater cables and sensors for real-time monitoring of offshore tectonic activities, believed to be the world’s most advanced system, allowing for nearly 20 seconds of additional warning time and shortening tsunami notifications by up to 20 minutes.
Most Systems Rely on Sensors, Phones, and Public Alerts
Earthquakes generate various motion types, starting with P waves that travel quickly and cause minor tremors. This is followed by slower S waves that bring more intense shaking, and finally the L wave, which is predominantly destructive.
Google’s Android system operates using accelerometers in devices—sensors that also help tilt the screen orientation. When P waves are detected by a stationary Android phone, it alerts Google’s detection center, which correlates data from many phones in the vicinity to confirm the earthquake and send out warnings.
Most earthquake early warning systems employ seismometers and other sensors that transmit motion data to regional networks for rapid location and magnitude assessments. Once a quake’s strength surpasses a specific threshold, alerts are disseminated to potentially affected areas.
In the U.S., alerts are sent through multiple channels, including emergency radio broadcasts, various mobile applications, and public alerts. It’s worth noting that some individuals might receive several alerts for the same event, while others, especially in rural locales, may miss out completely.
Warning Time Relies on Proximity to the Epicenter
Signals used for detecting tremors and issuing warnings travel at the speed of light, outpacing seismic waves that travel through the Earth’s surface. It’s a bit like a thunderstorm: the farther you are from a lightning strike, the longer it takes for the thunder to reach you.
Those positioned closest to the epicenter might have limited or no warning before the significant shaking starts. Conversely, individuals farther away have a bit more time to prepare, albeit usually just a few seconds.
