Evolution of Oceanic Lithosphere

Plate tectonics is expressed most simply in oceanic plates, and yet knowledge of the seismic properties of the oceanic upper mantle is based primarily on studies from the Pacific basin. Factors such as spreading rate, absolute plate motion, and intraplate volcanism vary between oceanic settings, and the full range in parameters should be considered when forming ideas about mantle dynamics and lithosphere evolution within ocean basins. We have measured and analyzed new data sets of travel time and amplitude for Rayleigh waves traveling through the mantle beneath the Atlantic and Indian oceans. We have shown that, in contrast to results for the Pacific, seismic velocities in the Atlantic are not consistent with the half-space cooling model and are better fit by a 75-km thick plate, suggesting different cooling histories for the two basins (James et al., G3, 2014). Results for the Indian Ocean are in progress.

Evolution of Oceanic Lithosphere

Plate tectonics is expressed most simply in oceanic plates, and yet knowledge of the seismic properties of the oceanic upper mantle is based primarily on studies from the Pacific basin. Factors such as spreading rate, absolute plate motion, and intraplate volcanism vary between oceanic settings, and the full range in parameters should be considered when forming ideas about mantle dynamics and lithosphere evolution within ocean basins. We have measured and analyzed new data sets of travel time and amplitude for Rayleigh waves traveling through the mantle beneath the Atlantic and Indian oceans. We have shown that, in contrast to results for the Pacific, seismic velocities in the Atlantic are not consistent with the half-space cooling model and are better fit by a 75-km thick plate, suggesting different cooling histories for the two basins (James et al., G3, 2014). Results for the Indian Ocean are in progress.

Evolution of Oceanic Lithosphere

Plate tectonics is expressed most simply in oceanic plates, and yet knowledge of the seismic properties of the oceanic upper mantle is based primarily on studies from the Pacific basin. Factors such as spreading rate, absolute plate motion, and intraplate volcanism vary between oceanic settings, and the full range in parameters should be considered when forming ideas about mantle dynamics and lithosphere evolution within ocean basins. We have measured and analyzed new data sets of travel time and amplitude for Rayleigh waves traveling through the mantle beneath the Atlantic and Indian oceans. We have shown that, in contrast to results for the Pacific, seismic velocities in the Atlantic are not consistent with the half-space cooling model and are better fit by a 75-km thick plate, suggesting different cooling histories for the two basins (James et al., G3, 2014). Results for the Indian Ocean are in progress.

Evolution of Oceanic Lithosphere

Plate tectonics is expressed most simply in oceanic plates, and yet knowledge of the seismic properties of the oceanic upper mantle is based primarily on studies from the Pacific basin. Factors such as spreading rate, absolute plate motion, and intraplate volcanism vary between oceanic settings, and the full range in parameters should be considered when forming ideas about mantle dynamics and lithosphere evolution within ocean basins. We have measured and analyzed new data sets of travel time and amplitude for Rayleigh waves traveling through the mantle beneath the Atlantic and Indian oceans. We have shown that, in contrast to results for the Pacific, seismic velocities in the Atlantic are not consistent with the half-space cooling model and are better fit by a 75-km thick plate, suggesting different cooling histories for the two basins (James et al., G3, 2014). Results for the Indian Ocean are in progress.