Tasks

The NGA West program concluded in 2008. Subsequently two other NGA programs began in 2010, NGA East and NGA West 2. The NGA East Program is developing a new set of comprehensive & broadly accepted attenuation relationships for the Central and Eastern US.

The NGA West2 program is a followup to the original NGA program and will be investigating the modeling of directivity and directionality; verification of NGA-West models for recent small, moderate and large magnitude events; scaling of ground motion prediction equations (GMPE) for different levels of damping; development of GMPEs for vertical ground motion; treatment of epistemic uncertainty; and evaluation of soil amplification factors in NGA models versus NEHRP site factors. The NGA-West 2 program started on March 1, 2010 and will conclude in 30 months.