Laurie Baise, Professors at Tufts, presents "Observations and Characterization of Complexity in Earthquake Site Response" as part of the EAPS Geophysics Seminar.

"Earthquake site response is an important aspect of earthquake hazard and refers to near surface amplification of waves due to local structure and changes in impedance. Using weak ground motions recorded in vertical arrays, the consistency and complexity of site response can be better evaluated. Vertical arrays allow for the direct measurement of an empirical site transfer function by taking the spectral ratio of recorded ground motions at the surface and at depth. This empirical site transfer function can be used to evaluate whether site response models capture the observed behavior. The most common site response model assumes vertically propagating shear waves through laterally homogeneous horizontal layers of soil overlying bedrock (SH1D). In this talk, we will present cases of site response that are consistent and well behaved (consistent with SH1D), and others that are complex and require 2D or 3D models to account for spatial variability and structure. We will describe the taxonomy for site response complexity that we developed. Finally, we will discuss site response in the city of Boston."

Seminar in Geophysics (12.571) is a class for EAPS graduate students in geophysics. All members of the MIT Community are welcome to join for presentations by guest speakers which will take place approximately every two weeks during the spring semester on Tuesday mornings 10am in 54-209 and on Zoom. Titles and abstracts for talks will be posted here when available.