TY - JOUR
T1 - Upper mantle thermal variations beneath the Transantarctic Mountains inferred from teleseismic S-wave attenuation
AU - Lawrence, Jesse F.
AU - Wiens, Douglas A.
AU - Nyblade, Andrew A.
AU - Anandakrishan, Sridhar
AU - Shore, Patrick J.
AU - Voigt, Donald
PY - 2006/2/16
Y1 - 2006/2/16
N2 - This study examines teleseismic S-wave attenuation variations between the Ross Sea in West Antarctica and Vostok Subglacial Highlands in East Antarctica. These analyses indicate that δt* is ∼1 second greater beneath the Ross Sea than East Antarctica, with the transition occurring beneath the Transantarctic Mountains. While the structure is non-unique, low attenuation beneath East Antarctica is consistent with thick subcontinental lithosphere (≥250 km) and negligible asthenosphere. In contrast, the Ross Sea possesses a thin lithosphere underlain by thick, highly anelastic asthenosphere. Independent temperature estimates from velocity and quality factor indicate that the mantle is 200-400°C colder beneath East Antarctica than the Ross Sea between 80 and 220 km depth. The temperature variation beneath the Transantarctic Mountains may have assisted in the asymmetric uplift of the mountains. Attenuation and velocity anomalies within East Antarctica may delineate regions of elevated temperature, representing recently modified sections between older lithospheric blocks.
AB - This study examines teleseismic S-wave attenuation variations between the Ross Sea in West Antarctica and Vostok Subglacial Highlands in East Antarctica. These analyses indicate that δt* is ∼1 second greater beneath the Ross Sea than East Antarctica, with the transition occurring beneath the Transantarctic Mountains. While the structure is non-unique, low attenuation beneath East Antarctica is consistent with thick subcontinental lithosphere (≥250 km) and negligible asthenosphere. In contrast, the Ross Sea possesses a thin lithosphere underlain by thick, highly anelastic asthenosphere. Independent temperature estimates from velocity and quality factor indicate that the mantle is 200-400°C colder beneath East Antarctica than the Ross Sea between 80 and 220 km depth. The temperature variation beneath the Transantarctic Mountains may have assisted in the asymmetric uplift of the mountains. Attenuation and velocity anomalies within East Antarctica may delineate regions of elevated temperature, representing recently modified sections between older lithospheric blocks.
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U2 - 10.1029/2005GL024516
DO - 10.1029/2005GL024516
M3 - Article
AN - SCOPUS:33645519564
VL - 33
JO - Geophysical Research Letters
JF - Geophysical Research Letters
SN - 0094-8276
IS - 3
M1 - L03303
ER -