Receiver function analysis - Seismic imaging of the crust beneath TROLL seismic station in Queen Maud Land, Antarctica

Abstract

In this this study, receiver function analysis of the crust underneath TROLL seismic station in Queen Maud Land, Antarctica was performed. An analysis of the neighboring seismic station SNAA was carried out as well to provide ground of comparison. Receiver function analysis is a seismic method utilizing that fact that teleseismic P-waves encountering a subsurface boundary at particular angels of incidence will result in refracted and reflected P and S-waves. The generated waves of interest are those resulting from the local structure underneath the receiver, and by deconvolution and source equalization, these local effects can be isolated into a data series known as the receiver function. An estimate of the local velocity-structure model can then be computed through an iterative process of forward modeling and inversion. Throughout this study, the receiver function analysis is carried out in a step-by-step manner; from raw three component seismograms to estimated structure model. In addition, crustal depth and V P V S ratios were estimated through the method of H-κ analysis. Computation programs made available by Charles Ammon were used for the processing. The programing codes are a collaboratively written by Tom Owens, George Randall, George Zandt, and Charles Ammon. In addition, the Seismic Analysis Code (SAC) program was used along with auxiliary SAC programs provided by George Helffrich. The crustal thickness beneath the TROLL seismic station was modeled to be approximately 42.5 km thick. The confidence in this result is further supported by similar studies conducted at surrounding seismic stations.