Picture of an earthquake alert. Photo: VCG

The Institute of Care-life, a Chengdu-based disaster reduction laboratory, apologized after users received a false 7.7-magnitude earthquake alert for Yibin, Southwest China's Sichuan Province, where a 4.7-magnitude earthquake struck on Monday morning.

A 4.7-magnitude earthquake struck Yibin at 8:26 am on Monday, according to the China Earthquake Networks Center. However, the Institute of Care-life issued a 7.7-magnitude earthquake alert just five seconds after the quake struck, causing panic among many users. 

In response to the false alarm, the institute said that its earthquake early-warning network initially estimated the quake at magnitude 7.7 five seconds after it occurred, before revising the estimate to 6.4 at the sixth second, 3.7 at the seventh second, 4.1 at the eighth second and 3.9 at the 16th second. The estimated magnitude automatically converged to 3.9 by the 17th second after the earthquake, the institute said.

Addressing the significant discrepancy, the institute said that deviations in estimates of an earthquake's magnitude and epicenter are inevitable to some extent, as early-warning information is generated automatically shortly after a quake begins, before the seismic event has ended.

The institute apologized for the inaccurate alert and said it would investigate the cause as soon as possible while improving its technology and services.

Global Times