On July 12, the China Earthquake Networks Center held a briefing meeting on the 5.1 earthquake in Gushan, Tangshan, confirming that the 5.1 earthquake that occurred in Guye District, Tangshan City, Hebei Province that morning was a magnitude 5 earthquake in the 7.8 Tangshan earthquake in 1976. Aftershocks undulating activity.
Why does a magnitude 5 aftershock occur more than 40 years after the Tangshan earthquake? Researcher Jiang Haikun, chief engineer of the Earthquake Prediction Department of the China Earthquake Networks Center, explained that the duration of aftershocks is related to many factors, the most important of which is the magnitude of the main shock. The larger the magnitude of the main shock, the longer the duration of the aftershock. However, the magnitude of the main shock is similar, and the duration of the aftershocks will also vary greatly.
He pointed out that according to preliminary research results, the duration of aftershock activity is actually related to the seismic tectonic loading rate. The faster the tectonic loading rate, the faster the aftershock attenuation. Compared with the eastern and western parts of mainland China, the geological tectonic loading rate in Tangshan is very slow, so The aftershocks of the Tangshan earthquake also lasted very long, and would last for hundreds of years. This is also a field of aftershock research that is currently generally accepted by the international scientific community. (Reporter Sun Zifa editor Guo Shihao)
Editor in charge: [Zhou Zhaojun]