Multiple aftershocks triggered after Sichuan quake

Workers clean a road at Shuanghe town in Changning county of Yibin city, Southwest China’s Sichuan province, June 18, 2019. [Photo/Xinhua]

Aftershocks are expected to continue to rock Yibin’s Changning county in Sichuan province following the magnitude 6.0 earthquake that struck late on Monday, officials of the China Earthquake Networks Center said on Tuesday.

By 4 pm on Tuesday, 77 aftershocks above magnitude 2.0 had been recorded.

Monday night’s earthquake occurred at a secondary fault at the edge of the Sichuan Basin, not in the same area of the tectonic belt that was the origin of magnitude 8.0 earthquake in Wenchuan in 2008.

Wang Haitao, a researcher with the center, said that the aftershocks are highly active because the area lies in a geological fold where the faults are small and wide spread.

“Once a big earthquake happens, the connected faults will become active, triggering more aftershocks,” he said.

Wang Song, project management director with center, said that Changning has been relatively stable terrain historically, but has been geologically active in the past few decades.

The earthquake, which hit Changning on Monday evening, has killed 13 people so far.

People were successfully evacuated in nearby Yibin and Chengdu thanks to a warning issued by the Continental Earthquake Warning Center, which was jointly built by the Institute of Care-Life in Chengdu and Ministry of Emergency Management in 2011.

Wang Song, the director, said that the nation has also been making efforts to build a nationwide early warning system since 2015.

The system, also known as the National Seismic Intensity Rapid Reporting and Early Warning project, will warn the public within a few seconds after an earthquake and report quickly its intensity, according to Wang.

“The warning, delivered to the public, is to urge people to evacuate or take measures to protect themselves. But more importantly, the system will report the earthquake’s intensity in just 10 minutes to give more accurate information to rescue teams,” he said.

According to him, it now takes a couple of days for geologists to report the intensity after performing site investigations.

(China Daily 06/19/2019 page4)