High-resolution seismic profiling: development of acquisition, processing, and interpretation for the practical implementation of the method in shallow sub-surface exploration and engineering

In the last few years there has been a general increase in the activities in the field of high-resolution seismic profiling. A growing interest in shallow sub-surface exploration probably underlies this development. Major attention is paid to the adaptation of highresolution seismic profiling for engineering purposes. Commercial applicability is one of the main points of interest and improvements are principally found in the field of data acquisition. At the University of Utrecht the interest in the development of high-resolution seismic profiling dates from 1976. The wish to obtain information on recent sedimentary structures in tidal areas resulted in a feasibility study by Herber, Runia and Helbig (1981). No direct commercial application was thought of during this study. Data proved to be of very good quality, mainly due to the absence of a weathering layer and the relatively low noise level. Further developments were focussed on the improvement of processing and interpretation methods, and on the adaptation of acquisition techniques in order to increase vertical- and lateral resolution. A processing and interpretation package was written and expanded by staff and students and field equipment was updated. Doomenbal and Helbig (1983) gave a detailed description of the activities in the period 1981 to 1983. It was stressed by the authors that the results pertained to tidal areas only. The research presented in this thesis addresses the further development of highresolution seismic profiling towards a method for shallow sub-surface exploration. Within this context three major aspects are presented. In the first place the extension of the method towards the acquisition, processing, and interpretation of 3-D high-resolution seismic data is described in chapter 2. The second aspect this thesis addresses is the development of onshore high-resolution seismic profiling. A general description of onshore profiling is given in chapter 3 and some field examples are presented. In chapter 4 a case history of an onshore seismic survey is presented emphasizing the possibility to combine refraction- and reflection information in processing and interpretation. The problems relating to the static correction of high-resolution seismic data are discussed in chapter 5. A method for static corrections that can generally be used in seismic profiling, including standard surveys, is presented. Finally, the relationship between high-resolution seismic data and geology is dealt with. Chapter 6 discusses the correlation between clastic tidal deposits and their seismic facies. The development of high-resolution seismic profiling has by no means reached an end. Hence, the overview presented in this thesis is not complete. Further research has to be carried out addressing, e.g., the problems that arise from weathering layer effects and the time-to-depth conversion (Brouwer, Douma, and Helbig, 1985).