Abstract
Sonobuoys provide an alternative to using long streamers while conducting multi-channel seismic (MCS) studies, in order to provide deeper velocity control. We present analysis and modeling techniques for interpreting the sonobuoy data and illustrate the method with ten overlapping sonobuoys collected in the Ross Sea, offshore from Antarctica. We demonstrate the importance of using the MCS data to correct for ocean currents and changes in ship navigation, which is required before using standard methods for obtaining a 1D velocity profile from each sonobuoy. We verify our 1D velocity models using acoustic finite-difference (FD) modeling and by performing depth migration on the data, and demonstrate the usefulness of FD modeling for tying interval velocities to the shallow crust imaged using MCS data. Finally, we show how overlapping sonobuoys along an MCS line can be used to construct a 2D velocity model of the crust. The velocity model reveals a thin crust (5.5 ± 0.4 km) at the boundary between the Adare and Northern Basins, and implies that the crustal structure of the Northern Basin may be more similar to that of the oceanic crust in the Adare Basin than to the stretched continental crust further south in the Ross Sea.
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References
Anderson JB (1999) Antarctic marine geology. Camb University Press, Cambridge
Cande SC, Stock JM (2006) Constraints on the timing of extension in the Northern Basin, Ross Sea. 9th International symposium on Antarctic earth science proceeding
Clayton R, McMechan G (1981) Inversion of refraction data by wave field continuation. Geophysics 46:860–868
Close DI, Watts A, Stagg H (2009) A marine geophysical study of the Wilkes Land rifted continental margin, Antarctica. Geophysical J Int 177(2):430–450
Cochrane GR, De Santis L, Cooper AK (1995) Seismic velocity expression of glacial sedimentary rocks beneath the Ross Sea from sonobuoy seismic-refraction data, geology and seismic stratigraphy of the Antarctic margin. Antarctic Res Ser 68:261–270
Cooper A, Davey F, Cochrane G (1987) Structure of extensionally rifted crust beneath the western Ross Sea and Iselin Bank, Antarctica, from sonobuoy seismic data. The Antarctic continental margin: geology and geophysics of the Western Ross Sea. Published by the Circum-Pacific Council of Energy and Mineral Resources, Earth Science Ser 5B:93–117
Ewing M, Heezen BC (1956) Some problems of Antarctic submarine geology. In: Carey AP, Gould LM, Hulbert EO, Odishaw H, Smith WE (eds) Antarctica in the IGY. Geophys Monogr 1, pp 75–81
Fowler CMR (1990) The solid earth: an introduction to global geophysics. Camb University Press, Cambridge
Geissler WH, Jokat W (2004) A geophysical study of the northern Svalbard continental margin. Geophysical J Int 158(1):50–66
Granot R, Cande S, Stock J, Davey F, Clayton R (2010) Postspreading rifting in the Adare Basin, Antarctica: regional tectonic consequences. Geochem Geophys Geosyst 11(8):Q08005. doi:10.1029/2010GC003105
Houtz R, Davey F (1973) Seismic profiler and sonobuoy measurements in Ross Sea, Antarctica. J Geophys Res 78(17):3448–3468
Jones EJW (1999) Marine geophysics. Wiley, London
Jones GD, Barton PJ, Singh SC (2007) Velocity images from stacking depth-slowness seismic wavefields. Geophys J Int 168(2):583–592
McMechan GA, Ottolini R (1980) Direct observation of a p-τ curve in a slant stacked wave field. Bull Seismol Soc Am 70(3):775
NBP0701 Data Report (2007) prepared by Ayers J. Available at http://www.marine-geo.org/tools/search/data/field/NBPalmer/NBP0701/docs/NBP0701Report.htm
Ritzmann O, Jokat W, Czuba W, Guterch A, Mjelde R, Nishimura Y (2004) A deep seismic transect from Hovgärd Ridge to northwestern Svalbard across the continental ocean transition: a sheared margin study. Geophys J Int 157(2):683–702
Selvans MM, Stock JM, Clayton RW, Cande S, Davey F, Granot R (submitted Sept. 30, 2011) Deep crustal structure of the Adare and Northern Basins, Ross Sea, Antarctica, from sonobuoy data. J Geophys Res
Shipp RM, Singh SC (2002) Two dimensional full wavefield inversion of wide aperture marine seismic streamer data. Geophys J Int 151(2):325–344
Stagg HMJ, Colwel J, Direen N, OíBrien P, Bernardel G, Borissova I, Brown B, Ishirara T (2004) Geology of the continental margin of Enderby and Mac. Robertson Lands, East Antarctica: insights from a regional data set. Marine Geophys Res 25(3):183–219
Tréhu A, Behrendt JC, Fritsch J (1993) Generalized crustal structure of the Central basin, Ross Sea, Antarctica. In: Damaske D, Fritsch J (eds) German Antarctic North Victoria Land Expedition 1988/1989. Bundesanstalt fur Geowissenschaften und Rohstoffe, Hannover, pp 291–311
Trey H, Cooper AK, Pellis G, della Vedova B, Cochrane G, Brancolini G, Makris J (1999) Transect across the West Antarctic rift system in the Ross Sea, Antarctica. Tectonophysics 301(1–2):61–74
Vireaux J (1986) P-SV wave propagation in heterogeneous media: velocity-stress finite difference method. Geophysics 51:889–901
Acknowledgments
We would like to thank Captain Mike Watson, the crew, and the Raytheon Polar Services Corporation technical staff on board the Nathaniel B. Palmer. This study was supported by National Science Foundation grants OPP04-40959 (S. Cande) and OPP-0440923 and OPP-0944711 (J. Stock and R. Clayton).
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Selvans, M.M., Clayton, R.W., Stock, J.M. et al. Using overlapping sonobuoy data from the Ross Sea to construct a 2D deep crustal velocity model. Mar Geophys Res 33, 17–32 (2012). https://doi.org/10.1007/s11001-011-9143-z
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DOI: https://doi.org/10.1007/s11001-011-9143-z