← Back to Sessions

Short-Period Surface Wave Propagation in the Bighorn Mountains Region, Wyoming

Session: Explosion Seismology Applications and Advances [Poster]

Type: Poster

Date: 4/19/2021

Presentation Time: 11:30 AM Pacific

Description: 

Short-period locally-observed Rayleigh waves, Rg, are of particular interest for monitoring small explosive sources. They can be the largest observed seismic phase at local distances (< 300 km) and provide unique sensitivity to the source depth of shallow seismic events. Characterizing the seismic sources that generate Rg requires an understanding of how propagation affects the observed signals at local distances. This study uses observed seismograms to assess changes in surface wave amplitude and radial motion in a region with diverse near-surface geology. We determine how waveform characteristics change depending on source and receiver emplacement conditions and during propagation through basins, foothills, and mountains. Using surface wave eigenfunction analysis and simulations using a 2D finite spectral element solver, we reproduce many features within the observed waveforms. Our observational and modeling results suggest that deep sedimentary basins in the region allow for the presence of prograde-polarized first higher mode and retrograde-polarized fundamental mode surface waves, while the adjacent mountains only support retrograde motion. Each mode provides distinct constraints on Earth structure and source characteristics, potentially enabling targeted inversions in future studies. Our findings provide insight into Rg propagation through complex Earth structure, improving our understanding of shallow propagation and source effects.

Presenting Author: Jonas Kintner

Student Presenter: No

Authors