PEER has just published Report No. 2015/07 titled “NGA-East: Ground-Motion Standard Deviation Models for Central and Eastern North America” as a new addition to the PEER Report Series. It was authored by Linda Al Atik.
Empirical ground-motion data from Central and Eastern North America (CENA) are used to analyze the components of ground-motion variability in CENA. Trends of ground-motion variability with parameters such as magnitude, distance, and VS30 are analyzed and compared to trends of ground-motion variability in other regions, particularly the Western United States (WUS) using the NGA-West2 dataset.
The CENA dataset is limited in magnitude range to small-to-moderate magnitudes and in frequency content to frequencies between 1 and 10 Hz due to the bandwidth limitations of the recordings. Therefore, standard deviation models developed using the CENA ground-motion data cannot be reliably extrapolated to large magnitudes and to frequencies outside of 1 to 10 Hz. As a result, standard deviation models from other regions such as WUS and Japan are used to inform the extrapolation of CENA standard deviations and overcome data limitations. Candidate models for between-event standard deviation (τ), single-station within-event standard deviation (φSS), and site-to-site variability (φS2S) are developed for CENA. In turn, these models are combined to develop single-station sigma (σSS) and ergodic sigma models for CENA.