Some Problems and Experimental Results of Seismic Shallow Prospecting
In spite of the relatively small depth, the detection of underground empty spaces by means of seismic reflections methods creates a problem not resolved fundamentally, up to now. The difficulties result from the impossibility of the resolution of ground roll signals and the refractions on the one hand, and the reflections from detected object, on the other. The problems increase, when decreasing the depth of the object (only depths of several meters make a limit at which the detection becomes easier1). Few references show that, in spite of the universal principles of the proceeding, the method and the way of detection must be carefully chosen according to the geological conditions and the detected object parameters.
KeywordsMixed Layer Source Position Automatic Gain Control Tunnel Position Ground Roll
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- 1.J. Peragallo, Méthodes sismiques de subsurface: contribution à la détection des cavités souterraines, Thèse de doctorat, Université de Bordeaux I, 1976.Google Scholar
- 2.Y. Leplat, les cavités souterraines de la craie dans le nord de la France, Bull. Liaison Labo P.et Ch. 63, janv. – fév. 1983.Google Scholar
- 3.R.W. Knapp, Don. W. Steeples, High resolution common-depth — point reflection profiling: Field acquisition parameter design, Geophysics51, 2, 1986.Google Scholar
- 4.R.W. Knapp, Don. W. Steeples, High resolution common-depth — point seismic reflection profiling: Instrumentation, Geophysics,51, 2,1986.Google Scholar
- 5.Data from the geological map, made by Bureau de Recherches Geologique et Minières, Borehole nr. 7.229.Google Scholar
- 6.Y.A. Hunter, S.E. Pullan, R.A. Burns, R.M. Gagne and R.L. Good, Shallow seismic reflection mapping of the overburden-bedrock interface with the engineering seismograph — some simple techniques, Geophysic-, 49,8, 1984.Google Scholar
- 7.J.H. Cook, Seismic mapping of underground cavities using reflection amplitudes, Geophysics, XXX, 4, 1965.Google Scholar