Recently, I have computed several tests for one region with the same all parameters (seismic city, sources...), but different GMPEs by using NGA08 and NGA-WEST 2 in order to check their PGA and SA results.
I found that the PGA and SA results by using NGA-WEST 2 are much larger than the NGA08 ones.
Could anyone explain to me why the results are so different?
Thank you in advance.