Shallow Shear-wave Reflection Tests

Shallow shear wave reflection tests have been carried out at a variety of sites with differing surface conditions and overburden stratigraphy with the aim of obtaining shear wave reflections from the overburdenbedrock interface. Horizontal geophones (8 Hz and 50 Hz) and small “hammer and block of wood” sources have been used for most of these tests. Results have ranged from poor to excellent, with well-defined bedrock reflections being obtained in areas where groundroll energy is quickly attenuated and does not interfere with reflection events. In such cases, the use of shear wave reflection techniques may be complimentary to P-wave reflection methods or may offer improved resolution.