Comparison of strong-motion records and damage implications between the 2014 Yunnan M(S)6.5 Ludian earthquake and M(S)6.6 Jinggu earthquake

Serial destructive earthquakes have caused heavy casualties and economic losses to the city in southwestern of China. The Ludian M-s 6.5 earthquake and the Jinggu M-s 6.6 earthquake occurred in Yunnan province in 2014. There is a question of why the two events with almost the same level of magnitude caused differences in earthquake damage. To understand the uniqueness of the phenomenon, this paper focuses on the characteristics of the ground motions and post-earthquake field investigation for the two events. Firstly, we present an overview of the residuals between the Ludian earthquake and the Jinggu earthquake based on the YW06 Ground Motion Prediction Equation (GMPE), and explain the unusual destructiveness of the strong ground motion. Then we analyze the ground motion recordings at selected typical station, based on the strong motion parameters: equivalent predominant frequency and Arias intensity. The result exhibits a good agreement with the Chinese seismic intensity scale. This study would be helpful to gain a better knowledge of the characteristics and variability of ground motions for M(S)6 class earthquakes in China and to understand the implications to future earthquakes with similar focal mechanism and local condition.