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.
Original language | English |
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Pages (from-to) | 17-32 |
Number of pages | 16 |
Journal | Marine Geophysical Research |
Volume | 33 |
Issue number | 1 |
DOIs | |
State | Published - 1 Mar 2012 |
Keywords
- 2D velocity model
- Crustal structure
- Finite-difference
- Multi-channel seismic
- Ross Sea
- Sonobuoy
ASJC Scopus subject areas
- Oceanography
- Geophysics
- Geochemistry and Petrology