Nine-component refraction statics survey

Donald C. Lawton

A 9-component refraction seismic survey was conducted near Calgary. A steel hammer striking a wooden beam was used to generate S waves, and a seisgun was used to produce P waves. Data were recorded on single 3-component geophones. Good quality P, SV and SH refracted data were acquired. The water table was found to produce strong P-wave refracted arrivals but was transparent to S waves. Vp/Vs below the water table was greater than 8. Static corrections to the base of the weathered layer at a depth of 20 m were 40 ms for P-P data, 89 ms for P-SV data, and 138 ms for Sh-SH data. Weak shear-wave velocity anisotropy was found in unweathered Cretaceous elastic rocks in the study area.