土卫二和土卫四的浮冰壳由最小应力等值线支撑
Enceladus's and Dione's floating ice shells supported by minimum stress isostasy
摘要：
土卫二的重力和形状被解释为漂浮在全球海洋上的厚均衡冰壳，与天平动所暗示的薄壳相矛盾。在这里，我们提出了一个新的均衡模型，最大限度地减少地壳偏应力，并证明重力和形状的数据预测$\rm{38\pm4\,km}$厚的海洋下面的$\rm{23\pm4\,km}$厚壳同意-但独立的-天平动数据。均衡应力和潮汐应力的大小相当。南极地壳只有$7\pm4\rm\,km$厚，有利于打开水道，并通过应力集中增强潮汐耗散。土卫二的共振伴星土卫四也处于类似的最小应力等熵状态。它的重力和形状可以用$\rm{99\pm23\,km}$厚的均衡壳覆盖在$\rm{65\pm30\,km}$厚的全球海洋上来解释，从而为土卫四内的现代海洋提供了第一个明确的证据。
英文摘要：
Enceladus's gravity and shape have been explained in terms of a thick isostatic ice shell floating on a global ocean, in contradiction of the thin shell implied by librations. Here we propose a new isostatic model minimizing crustal deviatoric stress, and demonstrate that gravity and shape data predict a $\rm{38\pm4\,km}$-thick ocean beneath a $\rm{23\pm4\,km}$-thick shell agreeing with -- but independent of -- libration data. Isostatic and tidal stresses are comparable in magnitude. South polar crust is only $7\pm4\rm\,km$ thick, facilitating the opening of water conduits and enhancing tidal dissipation through stress concentration. Enceladus's resonant companion, Dione, is in a similar state of minimum stress isostasy. Its gravity and shape can be explained in terms of a $\rm{99\pm23\,km}$-thick isostatic shell overlying a $\rm{65\pm30\,km}$-thick global ocean, thus providing the first clear evidence for a present-day ocean within Dione.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
