On retrodictions of global mantle flow with assimilated surface velocities
Modeling past states of Earth's mantle and relating them to geologic observations such as continental‐scale uplift and subsidence is an effective method for testing mantle convection models. However, mantle convection is chaotic and two identical mantle models initialized with slightly differen...
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Published in | Geophysical research letters Vol. 42; no. 20; pp. 8341 - 8348 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Washington
Blackwell Publishing Ltd
28.10.2015
John Wiley & Sons, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | Modeling past states of Earth's mantle and relating them to geologic observations such as continental‐scale uplift and subsidence is an effective method for testing mantle convection models. However, mantle convection is chaotic and two identical mantle models initialized with slightly different temperature fields diverge exponentially in time until they become uncorrelated, thus limiting retrodictions (i.e., reconstructions of past states of Earth's mantle obtained using present information) to the recent past. We show with 3‐D spherical mantle convection models that retrodictions of mantle flow can be extended significantly if knowledge of the surface velocity field is available. Assimilating surface velocities produces in some cases negative Lyapunov times (i.e., e‐folding times), implying that even a severely perturbed initial condition may evolve toward the reference state. A history of the surface velocity field for Earth can be obtained from past plate motion reconstructions for time periods of a mantle overturn, suggesting that mantle flow can be reconstructed over comparable times.
Key Points
Long‐term retrodictions of mantle convection are hindered by chaotic drift
Reconstructions of past plate motion provide fundamental information about mantle flow in the past
Assimilation of past plate motion data greatly improves long‐term retrodictions of mantle convection |
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Bibliography: | ark:/67375/WNG-Z9ZDSQLC-6 istex:43CB3643DDDC107E9CDCCE9F54229F2061F4456F Gauss Centre for Supercomputing e.V. (www.gauss-centre.eu) GCS Supercomputer SuperMUC at Leibniz Supercomputing Centre (LRZ, www.lrz.de) ArticleID:GRL53564 German Research Foundation (DFG) - No. SPP 1375-SAMPLE ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0094-8276 1944-8007 |
DOI: | 10.1002/2015GL066001 |