论文标题
IO上的地下岩浆海洋：探索部分熔融行星的稳态
A subsurface magma ocean on Io: Exploring the steady state of partially molten planetary bodies
论文作者
论文摘要
IO内部的强烈潮汐加热在表面上产生活跃的火山，其内部结构长期以来一直是争论的主题。最近对Galileo磁力计数据的重新分析表明，在IO的地下区域中存在厚度为$ 50〜 $ 50〜公里的高熔体分数。该层是否是``岩浆海绵''，其相互连接的固体还是流变液体``岩浆海洋''都会改变潮汐加热的分布，也会影响各种观察结果的解释。为此，我们探索了岩浆海绵的稳定状态，并估计维持高度熔化所必需的内部加热量。我们的结果表明，IO内的潮汐耗散速率不足以维持$ ϕ> 0.2 $的部分熔体层，这表明这种层将迅速分为两个阶段。除非熔体和/或固体粘度处在估计范围的较高端，否则岩浆海绵将不稳定，因此在Khurana等人中建议的高熔体分数层。 （2011年）可能是地下岩浆海洋。
Intense tidal heating within Io produces active volcanism on the surface, and its internal structure has long been a subject of debate. A recent reanalysis of the Galileo magnetometer data suggested the presence of a high melt fraction layer with $>$50~km thickness in the subsurface region of Io. Whether this layer is a ``magmatic sponge'' with interconnected solid or a rheologically liquid ``magma ocean'' would alter the distribution of tidal heating and would also influence the interpretation of various observations. To this end, we explore the steady state of a magmatic sponge and estimate the amount of internal heating necessary to sustain such a layer with a high degree of melting. Our results show that the rate of tidal dissipation within Io is insufficient to sustain a partial melt layer of $ϕ>0.2$ for a wide range of parameters, suggesting that such a layer would swiftly separate into two phases. Unless melt and/or solid viscosities are at the higher end of the estimated range, a magmatic sponge would be unstable, and thus a high melt fraction layer suggested in Khurana et al. (2011) is likely to be a subsurface magma ocean.
