Browse > Article

Maximising the lateral resolution of near-surface seismic refraction methods  

Palmer, Derecke (School of Biological, Earth and Environmental Sciences, The University of New South Wales)
Publication Information
Geophysics and Geophysical Exploration / v.12, no.1, 2009 , pp. 85-98 More about this Journal
Abstract
The tau-p inversion algorithm is widely employed to generate starting models with most computer programs, which implement refraction tomography. This algorithm emphasises the vertical resolution of many layers, and as a result, it frequently fails to detect even large lateral variations in seismic velocities, such as the decreases which are indicative of shear zones. This study demonstrates the failure of the tau-p inversion algorithm to detect or define a major shear zone which is 50m or 10 stations wide. Furthermore, the majority of refraction tomography programs parameterise the seismic velocities within each layer with vertical velocity gradients. By contrast, the Generalized Reciprocal Method (GRM) inversion algorithms emphasise the lateral resolution of individual layers. This study demonstrates the successful detection and definition of the 50m wide shear zone with the GRM inversion algorithms. The existence of the shear zone is confirmed by a 2D analysis of the head wave amplitudes and by numerous closely spaced orthogonal seismic profiles carried out as part of a later 3D refraction investigation. Furthermore, an analysis of the shot record amplitudes indicates that a reversal in the seismic velocities, rather than vertical velocity gradients, occurs in the weathered layers. The major conclusion reached in this study is that while all seismic refraction operations should aim to provide as accurate depth estimates as is practical, those which emphasise the lateral resolution of individual layers generate more useful results for geotechnical and environmental applications. The advantages of the improved lateral resolution are obtained with 2D traverses in which the structural features can be recognised from the magnitudes of the variations in the seismic velocities. Furthermore, the spatial patterns obtained with 3D investigations facilitate the recognition of structural features such as faults which do not display any intrinsic variation or 'signature' in seismic velocities.
Keywords
GRM; near-surface; RCS; resolution; seismic refraction; 2D; 3D;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Aki, K., and Richards, P. G., 2002, Quantitative Seismology: University Science Books
2 Berry, M. J., 1971, Depth uncertainties from seismic first arrival studies: Journal of Geophysical Research, 76, 6464–6468. doi: 10.1029/JB076i0 26p06464
3 Domzalski, W., 1956, Some problems of shallow refraction investigations: Geophysical Prospecting, 4, 140–166. doi: 10.1111/j.1365-2478.1956. tb01401.x
4 Healy, J. H., 1963, Crustal structure along the coast of California fromseismic-refraction measurements: Journal of Geophysical Research,68, 5777–5787   DOI
5 Oldenburg, D.W., 1984, An introduction to linear inverse theory: Trans IEEEGeoscience and Remote Sensing, GE-22, 665–674
6 Palmer, D., 1980, The generalized reciprocal method of seismic refractioninterpretation. Society of Exploration Geophysicists, 104 pp
7 Palmer, D., 2003, Application of amplitudes in shallow seismic refractioninversion. 16th ASEG Conference and Exhibition, Adelaide (Abstract)
8 Palmer, D., 2006, Refraction traveltime and amplitude corrections for verynear-surface inhomogeneities: Geophysical Prospecting, 54, 589–604   DOI   ScienceOn
9 Palmer, D., 2007, Is it time to re-engineer geotechnical seismic refractionmethods? 19th ASEG Conference and Exhibition, Perth (Extended Abstract)
10 Palmer, D., and Jones, L., 2005, A simple approach to refraction statics withthe generalized reciprocal method and the refraction convolution section:Exploration Geophysics, 36, 18–25. doi: 10.1071/EG05018   DOI
11 Palmer,D., and Shadlow, J., 2008, Integrating long and shortwavelength staticswith the generalized reciprocal method and the refraction convolution section: Exploration Geophysics, 39, 139–147. doi: 10.1071/EG08019   DOI
12 Sj\ddot{o}gren, B., 2000,Abrief study of the generalized reciprocalmethod andsomelimitations of the method: Geophysical Prospecting, 48, 815–834. doi: 10.1046/j.1365-2478.2000.00223.x   DOI   ScienceOn
13 Palmer, D., 1992, Is forward modeling as efficacious as minimum variancefor refraction inversion? Exploration Geophysics, 23, 261–266; 521.doi: 10.1071/EG992261   DOI
14 Stefani, J. P., 1995, Turning-ray tomography: Geophysics, 60, 1917–1929.doi: 10.1190/1.1443923   DOI   ScienceOn
15 Treitel, S., and Lines, L., 1988, Geophysical examples of inversion (with agrain of salt): Leading Edge, 7, 32–35. doi: 10.1190/1.1439464   DOI
16 Zhu, X., Sixta, D. P., and Andstman, B. G., 1992, Tomostatics: turning-raytomography + static corrections: Leading Edge, 11, 15–23. doi: 10.1190/1.1436864   DOI
17 de Franco, R., 2005, Multi-refractor imaging with stacked refraction convolution section: Geophysical Prospecting, 53, 335–348. doi: 10.1111/j.1365-2478.2005.00478.x   DOI   ScienceOn
18 Merrick, N. P., Odins, J. A., and Greenhalgh, S. A., 1978, A blind zonesolution to the problem of hidden layers within a sequence of horizontal ordipping refractors: Geophysical Prospecting, 26, 703–721. doi: 10.1111/j.1365-2478.1978.tb01630.x   DOI   ScienceOn
19 Nettleton, L. L., 1940, Geophysical prospecting for oil. McGraw-Hill Book Company
20 Palmer, D., 1986, Refraction seismics: the lateral resolution of structure andseismic velocity. Geophysical Press
21 Slichter, L. B., 1932, Theory of the interpretation of seismic travel-time curvesin horizontal structures: Physics, 3, 273–295. doi: 10.1063/1.1745133   DOI
22 Hagedoorn, J. G., 1959, The plus-minus method of interpreting seismic refraction sections: Geophysical Prospecting, 7, 158–182. doi: 10.1111/j.1365-2478.1959.tb01460.x   DOI
23 Palmer, D., 1991, The resolution of narrow low-velocity zones with thegeneralized reciprocal method: Geophysical Prospecting, 39, 1031–1060.doi: 10.1111/j.1365-2478.1991.tb00358.x   DOI
24 Zhang, J., and Toks\ddot{o}z, M. N., 1998, Nonlinear refraction traveltime tomography: Geophysics, 63, 1726–1737. doi: 10.1190/1.1444468   DOI
25 Barton, R., and Barker, N., 2003, Velocity imaging by tau-p transformationof refracted traveltimes: Geophysical Prospecting, 51, 195–203. doi: 10.1046/j.1365-2478.2003.00365.x   DOI   ScienceOn
26 Palmer, D., 2001c, Measurement of rock fabric in shallow refractionseismology: Exploration Geophysics, 32, 307–314. doi: 10.1071/EG01307   DOI
27 Hawkins, L. V., 1961, The reciprocal method of routine shallow seismicrefraction investigations: Geophysics, 26, 806–819. doi: 10.1190/1.1438961   DOI
28 Palmer, D., 2008, Is it time to re-engineer geotechnical seismic refraction methods? First Break, 26, 69–77. doi: 10.1002/9780470432723   DOI
29 Palmer, D., Nikrouz, R., and Spyrou, A., 2005, Statics corrections for shallowseismic refraction data: Exploration Geophysics, 36, 7–17. doi: 10.1071/EG05007   DOI
30 Whiteley, R. J., and Greenhalgh, S. A., 1979, Velocity inversion and theshallow seismic refraction method: Geoexploration, 17, 125–141. doi: 10.1016/0016-7142(79)90036-X   DOI   ScienceOn
31 Palmer, D., 2009, Integrating short and long wavelength time and amplitude statics (preprint)
32 Ivanov, J., Miller, R. D., Xia, J., and Steeples, D., 2005b, The inverse problemof refraction travel times, part II; quantifying refraction nonuniqueness using a three-layer model: Pure and Applied Geophysics, 162, 461–477. doi: 10.1007/s00024-004-2616-0   DOI
33 Ruijtenberg, P. A., Buchanan, R., and Marke, P., 1992, Three-dimensionaldata improve reservoir mapping. In Sheriff, R.E. ed., Reservoir Geophysics. SEG, Tulsa, 122–130
34 Schuster, G. T., and Quintus-Bosz, A., 1993, Wavepath eikonal traveltimeinversion: theory: Geophysics, 58, 1314–1323. doi: 10.1190/1.1443514   DOI   ScienceOn
35 Ivanov, J., Miller, R. D., Xia, J., Steeples, D., and Park, C. B., 2005a, The inverse problem of refraction travel times, part I; types of geophysicalnonuniqueness through minimization: Pure and Applied Geophysics, 162,447–459. doi: 10.1007/s00024-004-2615-1   DOI
36 Palmer, D., 2001a, Imaging refractors with the convolution section: Geophysics, 66, 1582–1589. doi: 10.1190/1.1487103   DOI   ScienceOn
37 Chopra, S., and Marfurt, K. J., 2007, Seismic Attributes for Prospect Identification and Reservoir Characterization. Geophysical Developments No. 11, SEG, Tulsa
38 Lanz, E., Maurer, H., and Green, A. G., 1998, Refraction tomography over aburied waste disposal site: Geophysics, 63, 1414–1433. doi: 10.1190/1.1444443   DOI   ScienceOn
39 Whiteley, R. J., 1986, Electrical and seismic response of shallow volcanogenicmassive sulphide ore deposits. Ph D Thesis, University of New SouthWales, 393 pp
40 Cerven\acute{v}, V., and Ravindra, R., 1971, Theory of Seismic Head Waves.University of Toronto Press
41 Palmer, D., 2001b, Resolving refractor ambiguities with amplitudes: Geophysics, 66, 1590–1593. doi: 10.1190/1.1487104   DOI   ScienceOn
42 Drijkoningen, G. G., 2000, The usefulness of geophone ground-coupling experiments to seismic data: Geophysics, 65, 1780–1787. doi: 10.1190/1.1444862   DOI   ScienceOn
43 Hagedoorn, J. G., 1955, Templates for fitting smooth velocity functions to seismic refraction and reflection data: Geophysical Prospecting, 3, 325–338. doi: 10.1111/j.1365-2478.1955.tb01379.x   DOI
44 Hagiwara, T., and Omote, S., 1939, Land creep at Mt Tyausu-Yama(Determination of slip plane by seismic prospecting): Tokyo University Earthquake Research Institute Bulletin, 17, 118–137