Seismic velocity structure of upper oceanic crust in the western South Atlantic from full-waveform modeling
Abstract
According to our current understanding, the composition and structure of oceanic crust is relatively simple compared to continental crust. However, seismic images of the oceanic crust are rare due to low economic interest and the remoteness of most mid-ocean ridges. Furthermore, the crust underneath the oceans is extremely difficult to image using conventional seismic imaging methods due to its complex internal structure and scattering of seismic energy on rough seafloor or basement topography. Advances in seismic data processing enable us to create high-resolution velocity models of the upper oceanic crust using streamer data. These velocity models can provide us with clues on physical properties and seismic structure, thus helping us better understand upper crustal variability. We perform full-waveform inversion of two-dimensional (2-D) long-offset (12.5 km) streamer data to explore the fine-scale seismic velocity structure at the Mid-Atlantic Ridge (MAR) both on and off-axis. The results will build upon previous work revealing the regional seismic velocity distribution of 0-71 Ma upper oceanic crust at 31°S, between the MAR and the Rio Grande Rise. Two important issues that will be addressed are the nature of the seismic layer 2A/2B boundary and the distribution of oceanic faults, which may provide clues on the geometry of hydrothermal circulation.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.T43F0511K
- Keywords:
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- 7218 Lithosphere;
- SEISMOLOGY;
- 7220 Oceanic crust;
- SEISMOLOGY;
- 8120 Dynamics of lithosphere and mantle: general;
- TECTONOPHYSICS;
- 8416 Mid-oceanic ridge processes;
- VOLCANOLOGY