SEISMIC CHARACTERISTICS OF THE SOUTHERN NEW ENGLAND CRUST REVEALED BY FULL-WAVE AMBIENT NOISE TOMOGRAPHY

The eastern North American margin has undergone two complete Wilson cycles of assembly and breakup of the supercontinents, together with terrane accretion, rifting, and post-rift evolution. It is not clear how the continental crust has been modified by these tectonic processes. Southern New England, which is composed of a few tectonic terranes, is an ideal place to study the crustal modification associated with the tectonic activities inferred from surface geology. The deployments of the EarthScope Transportable Array (~70-km spacing) in the northeastern United States and the SEISConn (Seismic Experiment for Imaging Structure beneath Connecticut) array (~ 10-km spacing) have provided unprecedently dense coverage of seismic data for southern New England. We collected the continuous seismic recordings between 2013 and 2018 from all available seismic stations, and extracted high-quality surface-wave empirical Green’s functions at periods of 3-40 s. Using full-wave ambient noise tomography, we aim to construct a high-resolution 3-D velocity model for the crust. Our preliminary tomographic results demonstrate strong variations of the crustal velocities in southern New England, revealing a thinner crust beneath the Hartford Basin compared to the surroundings. We are finalizing the tomographic result for further interpretation of the tectonic implications, which will be presented at the conference.