Spatial correlations in CyberShake physics-based ground motion simulations

Yilin Chen, & Jack W. Baker

Published August 13, 2018, SCEC Contribution #8450, 2018 SCEC Annual Meeting Poster #007

This poster reports the results from quantifying spatial correlations in the intensity of ground shaking using physics-based simulations from the CyberShake platform. Currently, spatial ground motion variations in future earthquakes are predicted empirically, and calibrated using ground motion observations from densely recorded earthquakes. While useful, that calibration process requires strong assumptions about stationarity and isotropy of correlations due to the lack of repetitive ground motion intensity records at the same site. This project conducts non-stationary and anisotropic spatial variation estimation using CyberShake simulations. The results show that the method of Pearson's correlation coefficient is able to show the non-stationary and anisotropic behavior of spatial correlation. The results suggest that the geological condition and directivity of earthquake propagation have significant impact on spatial correlations. The role of between-event residual and within-event residual in spatial correlation are also be examined. Additionally, the spatial correlations observed in CyberShake simulations are compared to the empirical models from past earthquakes under stationarity and isotropy assumptions. The results show that the relationship between within-event correlation coefficient versus distance in CyberShake simulations is similar to the empirical models.

Key Words
spatial correlations, ground motion simulations, CyberShake

Chen, Y., & Baker, J. W. (2018, 08). Spatial correlations in CyberShake physics-based ground motion simulations. Poster Presentation at 2018 SCEC Annual Meeting.

Related Projects & Working Groups
Earthquake Engineering Implementation Interface (EEII)