当前位置: X-MOL 学术J. Geophys. Res. Planets › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Heat Production and Tidally Driven Fluid Flow in the Permeable Core of Enceladus
Journal of Geophysical Research: Planets ( IF 3.9 ) Pub Date : 2020-07-28 , DOI: 10.1029/2019je006209
Yang Liao 1 , Francis Nimmo 2 , Jerome A. Neufeld 3, 4, 5
Affiliation  

Saturn's moon Enceladus has a global subsurface ocean and a porous rocky core in which water‐rock reactions likely occur; it is thus regarded as a potentially habitable environment. For icy moons like Enceladus, tidal heating is considered to be the main heating mechanism, which has generally been modeled using viscoelastic solid rheologies in existing studies. Here we provide a new framework for calculating tidal heating based on a poroviscoelastic model in which the porous solid and interstitial fluid deformation are coupled. We show that the total heating rate predicted for a poroviscoelastic core is significantly larger than that predicted using a classical viscoelastic model for intermediate to large (>1014 Pa·s) rock viscosities. The periodic deformation of the porous rock matrix is accompanied by interstitial pore fluid flow, and the combined effects through viscous dissipation result in high heat fluxes particularly at the poles. The heat generated in the rock matrix is also enhanced due to the high compressibility of the porous matrix structure. For a sufficiently compressible core and high permeability, the total heat production can exceed 10 GW—a large fraction of the moon's total heat budget—without requiring unrealistically low solid viscosities. The partitioning of heating between rock and fluid constituents depends most sensitively on the viscosity of the rock matrix. As the core of Enceladus warms and weakens over time, pore fluid motion likely shifts from pressure‐driven local oscillations to buoyancy‐driven global hydrothermal convection, and the core transitions from fluid‐dominated to rock‐dominated heating.

中文翻译:

土卫二渗透性岩心中的热量产生和潮汐驱动流体流

土星的月亮土卫二有一个全球性的地下海洋和一个多孔的岩心,在其中可能发生水岩反应。因此,它被视为潜在的宜居环境。对于像土卫二这样的冰冷的卫星,潮汐加热被认为是主要的加热机制,在现有研究中通常使用粘弹性固体流变学对其进行建模。在这里,我们提供了一个基于多孔弹性模型的潮汐热计算新框架,在该模型中,多孔固体和间隙流体变形是耦合的。我们发现,对于多孔弹性弹性芯,预测的总加热速率明显大于对于大中(> 10 14  Pa ·s)岩石粘度。多孔岩石基体的周期性变形伴随着间隙孔隙流体的流动,通过粘性耗散产生的综合效应导致高热通量,特别是在两极。由于多孔基质结构的高可压缩性,岩石基质中产生的热量也得到了增强。为了获得足够可压缩的岩心和高渗透率,总热量可以超过10 GW(占月球总热量预算的很大一部分),而无需不切实际的低固体粘度。岩石和流体成分之间的热量分配最敏感地取决于岩石基质的粘度。随着土卫二的核心逐渐变暖和变弱,
更新日期:2020-08-26
down
wechat
bug