Thousands of smartphones lit up with alerts Tuesday night as the rumbles of a magnitude 5.2 earthquake were felt across central and southern California. The quake struck in Lamont, near Bakersfield, at 9:09 p.m. Tuesday, according to the United States Geological Survey (USGS). Dozens of aftershocks rattled the region and continued into Wednesday morning, with magnitudes ranging from 2.5 to 4.6.
This latest earthquake has put California’s newly developed earthquake early warning system to the test. The earthquake early warning system was launched by Governor Gavin Newsom in late 2019 to commemorate the 30th anniversary of the devastating 6.9 magnitude Loma Prieta earthquake that killed 63 people. Using highly sensitive ground motion detectors, the system can detect seismic activity before the shaking becomes noticeable to humans. It immediately sends flashing notifications to warn people in the affected area before the strongest shaking begins.
This Tuesday was a testament to the effectiveness of Newsom’s earthquake detection technology. According to a press release from Newsom’s office, the earthquake early warning system notified millions of Californians, some as soon as 35 seconds before the quake began. The warning time varied across the state, as warnings spread faster the closer they are to the earthquake’s epicenter. The press release also explained that California is using the earthquake early warning system not only to warn individuals, but also to automate protective measures, such as turning off water and gas valves, closing bridge gates and notifying school and medical personnel.
The alerts are provided by ShakeAlert, a computer program managed by the USGS. ShakeAlert works with the California Governor’s Office of Emergency Services (Cal OES) to calculate the magnitude of the earthquakes and estimate which areas of the state will experience earthquakes.
Most smartphones have early warning technology built into them, allowing alerts to be sent to millions of people within seconds. MyShake, a ShakeAlert-based app, is also available for free download on smartphones. Newsom’s office notes that MyShake sent out 517,354 alerts on Tuesday and that there were more than 46,692 new downloads of the MyShake app in just 12 hours following Tuesday’s earthquake.
