Marine Geophysical Researches

, Volume 18, Issue 2–4, pp 459–486 | Cite as

Contribution of the multibeam acoustic imagery to the exploration of the sea-bottom

Examples of SOPACMAPS 3 and ZoNéCo 1 cruises
  • J. M. Augustin
  • R. Le Suave
  • X. Lurton
  • M. Voisset
  • S. Dugelay
  • C. Satra
Article
Received:
Accepted:

Abstract

Since early 1991, the EM12 dual multibeam echo sounder mounted on R/V L'Atalante has been mainly used for regional mapping and more particularly for EEZ exploration. The acoustic imagery data, which is collected at the same time as the multibeam soundings, and positioned with the same accuracy, illustrates the variability of the acoustic interface.

The working principles of the multibeam echo souder are at rirst presented. The backscattering phenomena are then considered, where the echo structure is interpreted in terms of insonified area, propagation loss and backscattering strength; the latter, especially important for the seafloor acoustical characterization, is described as contributions from the interface roughness and the volume inhomogeneities. Problems associated with the seafloor type interpretation from the backscattered level data are briefly evoked. Then, the various operations associated with ‘mosaic’ computations are presented, describing the transition from the original time signals to the final image usable by geologists.

Three examples, selected from a large set of data collected by IFREMER for SOPAC (SOPACMAPS Project) and the Territory of New Caledonia (ZoNéCo Project), both in late 1993, show that there are well differentiated acoustic reflectivity levels. After a description of their regional geological environment, the three examples are presented with the main results. These reflectivities, not yet calibrated in terms of field truth, are tentatively related to the previous existing data on the nature of the bottom and to the basic rules of marine sedimentology.

Key words

Acoustics backscattering sonar image multibeam echo sounder sedimentology 
This is a preview of subscription content, log in to check access.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Augustin, J. M., Edy, C., Savoye, B. and Le, Drezen, E., 1994, Sonar Mosaic Computation from Multibeam Echo Sounder, Proc. IEEE Oceans '94, Brest, Vol. II, pp. 433–438.Google Scholar
  2. Baudron, J. C., Guillon, J. H. and Récy, J., 1976, Géochronologie par la méthode K/Ar du substrat volcanique de l'île Maré-Archipel des Loyauté (Sud-Ouest Pacifique). Bull. BRGM 2, IV, 3, 165–175.Google Scholar
  3. Brekhovskikh, L. M. and Lysanov, Yu. P., 1991, Fundamentals of Ocean Acoustics, Springer-Verlag, 270p.Google Scholar
  4. Brocher, T. M., 1985, On the Age Progression of the Seamounts West of the Samoan Islands, SW Pacific, in Brocher, T. M. (ed.), ‘Investigations of the Northern Melanesian Borderland’, Circum-Pacific Council for Energy and Mineral Resources, Earth Science Series 3, 173–186.Google Scholar
  5. Brocher, T. M., Wirasantosa, S., Theyer, F. and Mato, C., 1985, Regional Sedimentation Patterns along the Northern Melanesian Borderland, in Brocher, T. M. (ed.), ‘Investigations of the Northern Melanesian Borderland’, Circum-Pacific Council for Energy and Mineral Resources, Earth Science Series 3, 77–102.Google Scholar
  6. Chaproniere, G. C. H., 1985, Late Tertiary and Quaternary Foraminiferal Biostratigraphy and Paleobathymetry of Cores and Dredge Samples from Cruise KK820316 Leg 2, in Brocher, T. M. (ed.), ‘Investigations of the Northern Melanesian Borderland’, Circum-Pacific Council for Energy and Mineral Resources, Earth Science Series 3, 103–122.Google Scholar
  7. Daniel, J., Dugas, F., Dupont, J., Jouannic, C., Monzier, M. and Récy, J., 1976, La zone charnire Nouvelle Calédonie — Ride de Norfolk (SW Pacifique)—résultats des dragages et interpretation, Cah. ORSTOM, sr. Gol., 1, 95–105.Google Scholar
  8. De, Moustier, C., 1986, Beyond Bathymetry: Mapping Acoustic Backscattering from the Deep Seafloor with Sea Beam, JASA 79(2), 316–331.Google Scholar
  9. De, Moustier, C., 1991, Angular Dependence of 12 kHz Sea-Floor Acoustic Backscatter, JASA 90(1), 522–531.Google Scholar
  10. Dubois, J., Launay, J. and Récy, J., 1974, Uplift Movements in New Caledonia — Loyalty Islands Area and Their Plate Tectonics Interpretation, Tectonophysics 24, (1/2), 133–150.Google Scholar
  11. Duncan, R. A., 1985, Radiometric Ages from Volcanic Rocks Along the New Hebrides-Samoa Lineament, in Brocher, T. M. (ed.), ‘Investigations of the Northern Melanesian Borderland’, Circum-Pacific Council for Energy and Mineral Resources, Earth Science Series 3, 67–76.Google Scholar
  12. Dupont, J., Launay, J., Ravenne, C. and De, Broin, C. E. 1975, Données nouvelles sur la Ride de Norfolk (Sud Ouest Pacifique). C.R. Acad. Sc 281, 10, 605–608.Google Scholar
  13. Dupont, J., Lafoy, Y., Pautot, G., Le, Suavé, R., Cluzel, D., Missègue, F., Grandperrin, R., Hénin, C., Voisset, M., Durand Saint Omer, L., Gautheron, L., Butsher, J., Mollard, L., Rakoia, M. et groupe ZoNéCo, 1995, Etude morphostructurale de la zone sud des rides Nouvelle-Calédonie et Loyauté (ZEE de Nouvelle Calédonie, Pacifique Sud-Ouest), C.R. Acad. Sc. 320, IIA, 211–218.Google Scholar
  14. Fairbridge, R. W. and Steward, H. B., 1960, Alexa Bank, a Drowned Atoll in the Melanesian Border Plateau, Deep-Sea Research 7, 100–116.Google Scholar
  15. Francois and Garrison, 1982, Sound Absorption Based on Ocean Measurements — Par I: Pure Water and Magnesium Sulfate Contributions, JASA 72(3), 896–907.Google Scholar
  16. Hammerstad, E. and Pohner, F., 1990, Ultra Wide Swath Deep Sea Interferometric Multibeam Echo Sounder with Sea Bottom Imaging System, Proc. IEEE Oceans '90, Washington, D.C., pp. 63–68.Google Scholar
  17. Hammerstad, E., Pohner, F., Parthiot, F. and Bennet, J., 1991, Field Testing of a New Deep Water Multibeam Echo-Sounder, Proc. IEEE Oceans '91, Vol. II, 743–749.Google Scholar
  18. Hughes-Clarke, J., 1993, The Potentialities for Seabed Classification Using Backscatter from Shallow Water Multibeam Sonar, Proc. I.O.A. Vol. 14, 381–388.Google Scholar
  19. Ivakin, A. N. and Lysanov, Yu. P., 1981, Underwater Sound Scattering by Volume Inhomogeneities of a Medium Bounded by a Rough Surface, Sov. Phys. Acous. 27(3), 212–215.Google Scholar
  20. Ivakin, A. N. and Lysanov, Yu. P., 1981, Theory of Underwater Sound Scattering by Random Inhomogeneities of the Bottom, Sov. Phys. Acous., 27(1), 61–64.Google Scholar
  21. Jackson, D. R., Winnebrenner, D. P. and Ishimaru, A. 1986, Application of the Composite Roughness Model to High-Frequency Bottom Backscattering. J. Acous. Soc. Am. 79(5), 1410–1422.Google Scholar
  22. Kristensen et al., 1993, ESMAC, a Nordic Research Program for Mapping and Characterization of the Seafloor, Proc. I.O.A., Vol. 14, 131–140.Google Scholar
  23. Le, Suavé, R., Pichocki, C., Pautot, G., Hoffert, M., Morel, Y., Voisset, M., Monti, S., Amossé, J. and Kosakevitch, A., 1989, Geological and Mineralogical Study of Co Rich Ferromanganese Crusts from a Submerged Atoll in the Tuamotu Archipelago (French Polynesia), Marine Geology 87, 227–247.Google Scholar
  24. Lurton, X., Dugelay, S. and Augustin, J. M., 1994, Analysis of Multibeam Echo-Sounder Signals from the Deep Seafloor, Proc. IEEE Oceans '94, Brest, Vol III, 213–218.Google Scholar
  25. Monzier, M., 1993, Un modèle de collision arc insulaire-ride océanique. Evolution sismotectonique et pétrologique des volcanites de la zone d'affrontement arc des Nouvelles Hébrides-ride des Loyauté. Thèse Univ. Française du Pacifique, Nouméa, 2 vol., 322 p.Google Scholar
  26. SOPAC Technical Reports no192 to 199 (SOPACMAPS Project Final Report), 1994, unpublished.Google Scholar
  27. Sinton, J. M., Johnson, K. T. M. and Price, R. C., 1985, Petrology and Geochemistry of Volcanic Rocks from the Northern Melanesian Borderland, in Brocher, T. M. (ed.), ‘Investigations of the Northern Melanesian Borderland’, Circum-Pacific Council for Energy and Mineral Resources, Earth Science Series 3, 135–166.Google Scholar
  28. Urick, R., 1983, Principles of Underwater Sound, McGraw-Hill, 3d Edition, 433 p.Google Scholar

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • J. M. Augustin
    • 1
  • R. Le Suave
    • 2
  • X. Lurton
    • 3
  • M. Voisset
    • 2
  • S. Dugelay
    • 1
  • C. Satra
    • 2
  1. 1.Service Développement de Systèmes InformatiquePlouzanéFrance
  2. 2.Département Géosciences MarinesPlouzanéFrance
  3. 3.Laboratoire d'Acoustique Sous-MarineIfremer Centre de BrestPlouzanéFrance

Personalised recommendations