Seismic velocities in the North West Shelf Region, Australia, From Near-vertical and Wide-angle Reflection and Refraction Studies

Alexey Goncharov; Geoffrey O‘Brien; Barry Drummond

doi:10.1071/EG00347

ISSN: 0812-3985
E-ISSN: 1834-7533

Seismic velocities in the North West Shelf Region, Australia, From Near-vertical and Wide-angle Reflection and Refraction Studies
Authors Alexey Goncharov, Geoffrey O‘Brien and Barry Drummond
Publisher: Australian Society of Exploration Geophysicists
Source: Exploration Geophysics, Volume 31, Issue 1-2, Mar 2000, p. 347 - 352
DOI: https://doi.org/10.1071/EG00347
- Published online: 01 Mar 2000

Abstract

A significant limitation of conventional seismic reflection technology is that it poorly constrains seismic velocities in the deep part of the section. These velocities are needed for seismic migration, to convert from time to depth, and to estimate the likely rock composition at depth. Seismic observations at large offsets can compensate for this limitation. The Australian Geological Survey Organisation recorded high-quality refraction and wide-angle reflection seismic data using ocean-bottom seismographs (OBS) along 5 profiles on Australia’s North West Shelf, to maximum offsets of 300 km. The OBS transects coincide with previously acquired deep-crustal seismic-reflection profiles. Consequently, velocity information can now be derived from two independent data sets: common-depth point (near-vertical) reflection data and refraction/wide-angle reflection data. Residual (difference between these two velocity data sets) velocity images can be produced and analysed. Even within the top 5 km of the section residuals between the OBS- and CDP-derived interval velocities vary from -0.5 to +3.5 km/s and increase further with depth. Consequently, the depth equivalent of 4 s two-way time will vary by up to 1.2 km or 10%. The practical implications of co-processing of seismic velocity information are: improved seismic velocity estimation, more accurate depth migration and depth conversion of seismic data and less distortion of amplitudes and shapes of geological structures after depth conversion.

Article metrics loading...

/content/journals/10.1071/EG00347

2000-03-01

2026-01-22

From This Site

/content/journals/10.1071/EG00347

dcterms_title,dcterms_subject,pub_keyword

-contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution

10

5

Full text loading...

References

Al-Chalabi, M., 1994, Seismic velocities - a critique: First Break: 12, 589-596.
Colwell, J.B. and Kennard, J.M. (compilers), 1996, AGSO Petrel Sub-basin study 1995-1996: Summary Report, AGSO Record 1996/40.
Dix, C.H., 1955, Seismic velocities from surface measurements: Geophysics, 20, 68-86.
Dziewonski, A.M. and Anderson, D.L., 1981, Preliminary reference Earth model: Phys. Earth and Planet. Int., 25, 297-356.
Gardner, L.W., 1947, Vertical velocities from reflection shooting: Geophysics, 12, 221-228.
Goncharov, A., Collins, C., Petkovic, P., Fomin, T., Pilipenko, V., Drummond, B. and Lee, C.S., 1998a, Ocean-bottom seismograph and reflection surveys in the Petrel Sub-Basin: An integrated seismic study: Expl. Geophys., 29, 384-390.
Goncharov, A.G., Lizinsky, M. D., Collins, C.D.N., Kalnin, K.A., Fomin, T.N., Drummond, B.J., Goleby, B.R.G. and Platonenkova, L.N., 1998b, Intra-crustal "seismic isostasy" in the Baltic Shield and Australian Precambrian Cratons from deep seismic profiles and the Kola superdeep bore hole data, in Braun, J., Dooley, J., Goleby, B., Van der Hilst, R. and Klootwijk, C, Eds, Structure and evolution of the Australian continent: Geodynamics Series, 26, 119-138.
Pylypenko,V.N., 1982, Continuation of the wave field by the differential grid solution of the wave equation, in: Alekseyev, A.S., Ed., Application of numerical methods in studies of the lithosphere, Novosibirsk, Siberian Branch of the Academy of Sciences USSR, 144-154. (in Russian)
Riznichenko, Yu.V., 1946, Geometrical seismics in layered media, in: Proceedings of the Institute of Theoretical Geophysics, 2/1.
Zelt, C.A. and Smith, R.B., 1992, Seismic travel time inversion for 2-D crustal velocity structure: Geophys. J. Internat., 108, 16-34.

/content/journals/10.1071/EG00347

Article Type: Research Article

Most Cited This Month Most Cited RSS feed

- A comparison of smooth and blocky inversion methods in 2D electrical imaging surveys
  
  Authors M.H. Loke, Ian Acworth and Torleif Dahlin
- Reverse-Time Migration using the Poynting Vector
  
  Authors Kwangjin Yoon and Kurt J. Marfurt
- SkyTEM–a New High-resolution Helicopter Transient Electromagnetic System
  
  Authors K. I. Sorensen and Esben Auken
- An overview of a highly versatile forward and stable inverse algorithm for airborne, ground-based and borehole electromagnetic and electric data
  
  Authors Esben Auken, Anders Vest Christiansen, Casper Kirkegaard, Gianluca Fiandaca, Cyril Schamper, Ahmad Ali Behroozmand, Andrew Binley, Emil Nielsen, Flemming Effersø, Niels Bøie Christensen, Kurt Sørensen, Nikolaj Foged and Giulio Vignoli
- The Fast Marching Method: An Effective Tool for Tomographic Imaging and Tracking Multiple Phases in Complex Layered Media
  
  Authors Nicholas Rawlinson and Malcolm Sambridge
- 3-D Analytic Signal in the Interpretation of Total Magnetic Field Data at Low Magnetic Latitudes
  
  Authors Ian N. MacLeod, Keith Jones and Ting Fan Dai
- CMP cross-correlation analysis of multi-channel surface-wave data
  
  Authors Koichi Hayashi and Haruhiko Suzuki
- A new direct non-invasive groundwater detection technology for Australia
  
  Authors M. Schirov, A. Legchenko and G. Creer
- 3D inversion of airborne electromagnetic data using a moving footprint
  
  Authors Leif H. Cox, Glenn A. Wilson and Michael S. Zhdanov
- Notes On Rock Magnetization Characteristics In Applied Geophysical Studies
  
  Authors D. A. Clark and J. B. Emerson
More Less

Seismic velocities in the North West Shelf Region, Australia, From Near-vertical and Wide-angle Reflection and Refraction Studies

Abstract

Most Read This Month

Most Cited This Month Most Cited RSS feed