Polar Motion Dynamics on Slow-Rotating Venus: Signatures of Mantle Flow
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F25%3A10508369" target="_blank" >RIV/00216208:11320/25:10508369 - isvavai.cz</a>
Result on the web
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=m-GBttTpCX" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=m-GBttTpCX</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1029/2025AV001976" target="_blank" >10.1029/2025AV001976</a>
Alternative languages
Result language
angličtina
Original language name
Polar Motion Dynamics on Slow-Rotating Venus: Signatures of Mantle Flow
Original language description
With its 1 day lasting 243 days on Earth, Venus is the slowest-spinning planet in the Solar System and its rotational bulge is anomalously small. A rotational bulge stabilizes the orientation of planets. Having only a tiny stabilizer, the rotational pole of Venus has been expected to separate from the figure pole in response to mantle flow, which has been used to explain why both poles are observed to be 0.5 degrees apart. Here, we couple 3D mantle-convection simulations and polar motion dynamics to explore how mantle flow, and in particular surface mobilization, drives Venus's polar motion. We provide a predictive framework for polar motion on slow rotators and show that the spin/figure pole separation (or offset) follows a simple law: it scales with the figure-axis drift rate times the planet's Chandler period. Contrary to prior expectations, stronger internal loading does not amplify the offset, and the mantle-driven polar motion is smooth rather than wobbly, more similar to that of fast rotators. In models matching Venus's geoid, figure-axis drift rates reach only up to a few degrees/Myr, too slow compared to ca. 60 degrees/Myr that is needed to match the observed offset. We therefore exclude mantle convection as the cause of Venus' spin and figure poles separation, and suggest that atmospheric and solid tides are not balanced instead.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10500 - Earth and related environmental sciences
Result continuities
Project
<a href="/en/project/GA22-20388S" target="_blank" >GA22-20388S: Evolving Ice Shells - processes shaping planetary ice shells inferred from numerical modelling</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
AGU Advances
ISSN
2576-604X
e-ISSN
2576-604X
Volume of the periodical
6
Issue of the periodical within the volume
6
Country of publishing house
US - UNITED STATES
Number of pages
13
Pages from-to
e2025AV001976
UT code for WoS article
001631420100001
EID of the result in the Scopus database
2-s2.0-105024096842