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Tethys: Lithospheric thickness and heat flux from flexurally supported topography at Ithaca Chasma
Author(s) -
Giese Bernd,
Wagner Roland,
Neukum Gerhard,
Helfenstein Paul,
Thomas Peter C.
Publication year - 2007
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl031467
Subject(s) - lithosphere , impact crater , geology , heat flux , structural basin , flux (metallurgy) , seismology , geophysics , geomorphology , tectonics , heat transfer , mechanics , astrobiology , physics , materials science , metallurgy
We have identified flexural uplift along the flanks of Tethys' Ithaca Chasma using Cassini stereo‐derived topography. Modeling the topography as a broken elastic plate yields an effective elastic lithospheric thickness in the range of 5–7 km and, combined with the strength envelope of the lithosphere, a mechanical lithospheric thickness of 16–20 km. Surface heat fluxes are 18–30 mW/m 2 for adopted strain rates of 10 −17 –10 −14 s −1 . These heat fluxes are more than 4 times higher than those calculated from thermal history models of Tethys and indicate a strongly enhanced local heat flux associated with the formation of Ithaca Chasma. We use crater‐size frequency counts and a lunar‐like impact chronology to fix the time of formation of Ithaca Chasma at 4 Ga from present‐day. Ithaca Chasma predates the Odysseus basin and thus could not have been formed by this impact feature.