Shallow reflection seismic surveys, which are now regularly carried out by several universities and companies in the UK for site investigations, were the subject of a well attended meeting held in the School of Earth Sciences at the University of Birmingham on 25 October 1989. The meeting was organised on behalf of the Geological Society's Joint Association for Geophysics (JAG) because of the recent increase in the use of reflection techniques to investigate shallow geological structures down to depths of 100 m or more.
Several groups from the USA, Europe and the UK have been involved in the rapid development of the technique since digital recording instruments and portable PCs became available. This meeting brought together groups from the Universities of Birmingham, Leicester, Leeds, Cardiff and Reading and the British Geological Survey to discuss a wide range of problems and applications, and was attended by more than 70 delegates.
Introductory talks by R. King (Birmingham) and I. Hill (Leicester) described the basic principles behind the technique and showed that good results could be achieved with standard portable seismic instruments. High-frequency geophones are generally laid out at 2 m to 5 m intervals from a source of high-frequency energy such as a buffalo gun (Leicester University) or a sledge hammer (preferred by Birmingham). The seismic energy returning to the surface after a reflection at sub-surface interfaces is recorded in digital form for later processing. Field techniques are designed to enhance the strength of the signals.
Although much of the sophisticated data