Spatial distribution of ground motion

Sponsors: NZ Earthquake Commission (EQC), Ministry of Business, Innovation and Employment (MBIE)

Collaborators: Matthew Hughes

Ground motions are spatially correlated as a result of a common earthquake source, potentially similar wave propagation paths and site response. Such spatial correlations should be accounted for both in the simulation of ground motions for forward prediction, and also in the interpolation of ground motions from past events.

Spatial distribution of peak ground acceleration (PGA) and velocity (PGV) from the Canterbury earthquakes

The spatial distribution of peak ground acceleration (PGA) and velocity (PGV) throughout the Canterbury region has been computed (for theory see: Bradley, 2014). The purpose of such a computation is to enable the back-analysis of liquefaction triggering of surficial soil deposits (using PGA) and lifeline performance (using PGV). This work has been commissioned by the Department of Building and Housing (DBH), and is provided here on their behalf. The formal DBH results are freely available on the Canterbury Geotechnical Database website.

Spatial distribution of peak ground acceleration from the 22 February 2011 Christchurch earthquake (top figure: median; bottom figure: lognormal standard deviation)