The Mw6.6 Lushan Earthquake Characteristic Analysis Based on High-Rate GPS

Thursday, 18 December 2014
Tie Gu, Sichuan Earthquake Bureau, Sichuan, China
10Hz Global Positioning System (GPS) observations of 20 Continual Operation Reference System (CORS) sites affected by 2013 Mw6.6 Lushan earthquake are used to analyze the characteristics of ground motion and research the relationship between peak horizontal displacement(PHD) and the magnitude. The results showall siteshave had ground motion with centimeter-level, QLAI, SCTQ and YAAN sites are obviously affected by earthquake for which PHD can reach approximately 50mm, other sites are within 18-28 mm. The scaling relationship between PHD and …from GPS observations show that PHD amplitudes decay approximately with, where is the epicentral distances of GPS sites. Magnitude inversion by the empirical relationship that Gutenberg deduced in 1945 show the result of Lushan earthquake is 6.78, and the shortest time to get the robust value is 142s, which indicate that a robust magnitude can be estimated within a few minutes after an earthquake event by using high-rate GPS.

Keywords: Lushan earthquake; high-rate GPS; ground moving; epicentral distance; peak horizontal displacement