Frequency‐Dependent Seismic Attenuation within the Hispaniola Island Region of the Caribbean Sea

Wedetermine frequency-dependentattenuation1=Qffor theHispanio- la region using direct S and Lg waves over five distinct passbands from 0.5 to 16 Hz. Data consist of 832 high-quality vertical and horizontal component waveforms recordedonshort-period andbroadbandseismometersfromthedevastating12January 2010 M 7.0 Haiti earthquake and the rich sequence of aftershocks. For the distance range 250-700 km, we estimate an average frequency-dependent Qf �� 224�� 27� f 0:64�� 0:073� using horizontal components of motion and note that Qf� estimated with Lg at regional distances is very consistent across vertical and horizontal components. We also determine a Qf �� 142�� 21� f 0:71�� 0:11� for direct S waves at local distances, ≤100 km. The strong attenuation observed on both vertical and horizontal components of motion is consistent with expectations for a tectonically active region. Online Material: Figures of filtered and broadband data, Lg- and S-wave ampli- tudes, and apparent frequency-dependent Q, and tables of earthquake and station parameters.