Dataset: Effects of subduction history on True Polar Wander driven by perturbations of Earth’s inertial moment from mantle convection
Supplemental data files for the submitted manuscript "Effects of subduction history on True Polar Wander driven by perturbations of Earth’s inertial moment from mantle convection" by C. M. Calvelage, Lorenzo Colli, Jonny Wu, Yi-An Lin, Yingcai Zheng, Moloud Rahimzadeh Bajgiran.
True Polar Wander (TPW) is the wholesale motion of the solid silicate Earth relative to its rotation axis from perturbing Earth’s moment of inertia. We investigate subduction history effects on TPW produced by large-scale mass redistributions during mantle convection. We explicitly calculate past mantle states using TERRA forward global geodynamic models that assimilate two different global plate reconstructions: the widely-used ‘Earthbyte’ model [1]; and, recently developed ‘Tomopac’ with circum-Pacific subduction histories that include more intra-oceanic subduction [2]. We compute the time-varying degree-2 non-hydrostatic geoid and derive TPW on Earth since the Jurassic; effects of radial viscosity profile, Earth’s excess ellipticity and lower mantle viscosity are considered. Alternative subduction histories produce significant differences (70°+) in modeled TPW that are comparable to changing assumed mantle viscosities. Tomopac improves the match between geodynamically modeled and paleomagnetically estimated TPW from between 100 Ma to present and best reproduces an abrupt TPW path change around ~50 Ma. Our results show that Earth’s subduction history and lower mantle radial viscosity are primary controls on Earth’s TPW history. Mantle viscosity and excess ellipticity may enhance or dampen TPW but not to the extent required for a hypothesized ’stable Earth’ since the Late Cretaceous.
For inquiries regarding the contents of this dataset, please contact the Corresponding Author listed in the README.txt file. Administrative inquiries (e.g., removal requests, trouble downloading, etc.) can be directed to data-management@arizona.edu
Funding
NSF EAR-1848327
CAREER: Unfolding Earth history back to the Mesozoic by incorporating seismic tomography into Pacific realm plate tectonic reconstructions
Directorate for Geosciences
Find out more...