CyberShake Map Generation Procedure

CyberShake hazard maps are generated using an interpolated difference approach. This procedure is outlined below.

First, a high resolution GMPE basemap is calculated. This GMPE basemap uses a high resolution Vs30 map as well as the Z1.0 and Z2.5 from the velocity model used for the CyberShake study of interest (a new GMPE map is generated for each alternative velocity model). The ERF used in these maps is the same as used in CyberShake.

GMPE Basemap

Then, at each CyberShake site, the difference is taken between the CyberShake value and the GMPE basemap value. This XYZ scatter data is then interpolated onto a regular grid.

CyberShake - GMPE Basemap, interpolated

These interpolated differences are then added on top of the GMPE basemap to generate the final CyberShake hazard map. This allows for the final map to keep the detail of the GMPE map, while exactly equaling the CyberShake value at each CyberShake site.

Final CyberShake Interpolated Difference Map

This differs from a raw interpolation of the CyberShake data, an example of which is included below for reference.

File:Cs raw cs.png

CyberShake Raw Interpolation