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Rayleigh wave 50s. Horizontal resolution. Current network (5yrs, M≥5.5). distance from the pole (deg). Rayleigh wave 50s. Horizontal resolution. Current network (5yrs, M≥5.5) New permanent stations (5yrs, M≥5.5). distance from the pole (deg). Rayleigh wave 50s. Horizontal resolution.
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Rayleigh wave 50s Horizontalresolution Current network (5yrs, M≥5.5) distance from the pole (deg)
Rayleigh wave 50s Horizontalresolution Current network (5yrs, M≥5.5) New permanent stations (5yrs, M≥5.5) distance from the pole (deg)
Rayleigh wave 50s Horizontalresolution Current network (5yrs, M≥5.5) New permanent stations (5yrs, M≥5.5) Regional arrays (1yr, M≥5.0) distance from the pole (deg)
Green Functions by Cross-Correlating Ambient Noise in Antarctica? Record section: Cross-correlate 1 month of ambient noise, Z Bandpass centered on: 20 sec 20 sec period Rayleigh wave
East Antarctica: old craton West Antarctica: recently rejuvenated mantle 100 km depth Results: Vs and temperature across Antarctica • W. vs E. Antarctica: @100 km > 1000 deg difference. @ 300 km. > 400 deg difference. • Along Transantarctic Mtns: @ 100 km, > 1deg/km laterally. • E. Antarctic cratonic core > 300 km thick, but much thinner nearer the coast.
100 km depth Results: Vs and temperature across Antarctica W. Ant. Rift So. Pole E. Ant. Craton A A’ temp • W. vs E. Antarctica: @100 km > 1000 deg difference. @ 300 km. > 400 deg difference. • Along Transantarctic Mtns: @ 100 km, > 1deg/km laterally. • E. Antarctic cratonic core > 300 km thick, but much thinner nearer the coast.
Results: Lithospheric thickness compared with other continents Other cratons lithospheric thickness
Mean of the Extrapolated Distribution Shapiro & Ritzwoller, EPSL, 2004,
Results: Lithospheric thickness vs mantle heat flow compared with other continents Other Continents Antarctica
Results: Lithospheric thickness vs mantle heat flow compared with other continents Other Continents Antarctica
Anomalous Mantle Structure Beneath Antarctica? Locations with relatively thin lithosphere but low heat flux. Cause? Erosion of the continental roots caused by Mesozoic rifting? or Simply poor lateral resolution?