DOI: 10.1002/2013GL057149
论文题名: The effect of an asymmetric core on convection in Enceladus' ice shell: Implications for south polar tectonics and heat flux
作者: Showman A.P. ; Han L. ; Hubbard W.B.
刊名: Geophysical Research Letters
ISSN: 0094-8412
EISSN: 1944-8143
出版年: 2013
卷: 40, 期: 21 起始页码: 5610
结束页码: 5614
语种: 英语
英文关键词: cryovolcanism
; icy satellites
; mantle convection
; Spacecraft missions (Cassini)
; tectonics
Scopus关键词: Cassini
; Cryovolcanism
; Episodic activity
; Icy satellites
; Mantle convection
; Northern Hemispheres
; Spherical models
; Threedimensional (3-d)
; Ice
; Plasticity
; Spheres
; Tectonics
; Three dimensional
; Heat flux
; asymmetry
; convection
; heat flux
; mantle convection
; Northern Hemisphere
; numerical model
; observational method
; plasticity
; tectonics
; terrain
; three-dimensional modeling
英文摘要: Enceladus exhibits a strong tectonic contrast between its south polar terrain (SPT), which is young and geologically active, and its northern hemisphere, which is relatively ancient and stable. Previous global three-dimensional (3-D) spherical models of convection exhibit patterns that are symmetrical around the equator and fail to explain the formation of a hemispheric dichotomy. Here we present global 3-D spherical models of convection in Enceladus' ice shell to show that convection in Enceladus' ice shell with plasticity and irregular core geometry can self-consistently generate a hemispheric dichotomy in tectonics and heat flux. With a spherical core, convection produces global overturning, which cannot explain the regional confinement of Enceladus' current tectonic activity to the SPT. Models with appropriate nonspherical core geometry and plasticity tend to produce overturning confined to the SPT or regional overturning in different regions at different times, which can explain the tectonic dichotomy and local age differences on Enceladus. Our models predict heat flows up to 5-10 gigawattts (GW) during active episodes, consistent with Cassini observations. Key Points Previous models have failed to explain Enceladus' hemispheric dichotomy We show that such a dichotomy emerges naturally from irregular core topography Episodic activity explains high current heat flux yet low time-mean power ©2013. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84887559259&doi=10.1002%2f2013GL057149&partnerID=40&md5=313c6247c36f9cea1491c8fb34b5dd9f
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/5676
Appears in Collections: 气候减缓与适应
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作者单位: Department of Planetary Sciences, Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, United States
Recommended Citation:
Showman A.P.,Han L.,Hubbard W.B.. The effect of an asymmetric core on convection in Enceladus' ice shell: Implications for south polar tectonics and heat flux[J]. Geophysical Research Letters,2013-01-01,40(21).