Imaging the shallow crust with teleseismic receiver functions

Teleseismic receiver functions (RFs) represent an estimate of the site-response to incoming seismic energy. This technique has long been a staple of the global earthquake community, as RFs are sensitive to impedance contrasts associated with major discontinuities in the crust and upper mantle. However, there is substantial debate in the community concerning the lateral and vertical resolution limits possible using these methods due to limitations resulting from ambient noise and non-uniform spatial sampling of finite-frequency wave kernels. Here, we take advantage of data from the LaBarge Passive Seismic Experiment to examine these questions in more detail. We find (1) that RFs can provide a robust image of the near-surface (<5 km) structure; (2) that vertical resolution may exceed 500 m and (3) that our results compare favourably to nearby wells. These results indicate that RF analysis can provide high-resolution images of the shallow crust, which has potential value for hydrocarbon exploration.