Long-term stability of Enceladus' uneven ice shell
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F19%3A10403988" target="_blank" >RIV/00216208:11320/19:10403988 - isvavai.cz</a>
Result on the web
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=z.L6XwmF0T" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=z.L6XwmF0T</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.icarus.2018.10.003" target="_blank" >10.1016/j.icarus.2018.10.003</a>
Alternative languages
Result language
angličtina
Original language name
Long-term stability of Enceladus' uneven ice shell
Original language description
We present a new model of Enceladus' internal structure based on the recent shape model by Tajeddine et al. (2017) and the gravity model by Iess et al. (2014). Assuming that the rocky core is homogeneous and in hydrostatic equilibrium, we derive a set of structural models that accurately reproduce the main characteristics of Enceladus' gravity field. In order to restrict the range of acceptable models we analyze the degree of compensation (ratio of the bottom to the surface load) at spherical harmonic degrees well constrained by the gravity data. In agreement with previous studies, we find that Enceladus' ice shell is close to equilibrium, with the degree of compensation approaching one for models with a hydrostatic core having a radius between 190 km and 195 km. By computing the flow of ice driven by variations in hydrostatic pressure on the ice water/interface, we demonstrate that the ice shell is in steady state, as suggested by the gravity and shape data, only if the viscosity of ice at the melting temperature is equal to or higher than 3 x 10(14) Pa s, corresponding to diffusion creep with a grain size of 1 mm or larger. The topographic anomalies are maintained by phase changes at the ice/water interface with a melting/freezing rate of a few mm/yr or smaller. This process is controlled by the heat flux at the top of the ocean, characterized by a strong degree-2 zonal component with amplitudes exceeding 60 rnW/m(2) in both south and north polar regions.
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
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2019
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Icarus
ISSN
0019-1035
e-ISSN
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Volume of the periodical
319
Issue of the periodical within the volume
2019
Country of publishing house
US - UNITED STATES
Number of pages
9
Pages from-to
476-484
UT code for WoS article
000455422800032
EID of the result in the Scopus database
2-s2.0-85054729585