Can a Combination of Convective and Magmatic Heat Transport in the Mantle Explain Io's Volcanic Pattern?. Issue 12 (10th December 2020)

• Record Type: Journal Article
• Authors: Steinke, T.; van Sliedregt, D.; Vilella, K.; van der Wal, W.; Vermeersen, B.
• Is Part Of: Journal of geophysical research. Volume 125:Issue 12(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-12-10
• Subjects: Io -- mantle convection -- tidal dissipation -- volcanism; Planets -- Periodicals; Geophysics -- Periodicals; 559.9
• DOI: 10.1029/2020JE006521
• Languages: English
• ISSNs: 2169-9097

Abstract

Abstract: Tidal dissipation makes Jupiter's moon Io the most volcanically active body in the solar system. Most of the heat generated in the interior is lost through volcanic activity. In this study, we aim to answer the questions: Can convection and melt migration in the mantle explain the spatial characteristics of Io's observed volcanic pattern? And, if so, what constraints does this place on the viscosity and thickness of the convective layer? We examine three different spatial characteristics of Io's volcanic activity: (i) The presence of global volcanism, (ii) the presence of large‐scale variations in Io's volcanic activity, and (iii) the number of Io's volcanic systems. Our study relies on the assumptions that melt in the mantle controls Io's global volcanism, that the large‐scale variations of Io's volcanic activity are caused by nonuniform tidal heating, and that the spatial density of volcanoes correlates with the spatial density of convective anomalies in the mantle. The results show that the observed small and large‐scale characteristics of Io's volcanic pattern can be explained by sublithospheric anomalies influenced and caused by convective flow. Solutions that allow for active volcanism and Io's specific large‐scale variations in volcanic activity range from a thick mantle of a high viscosity ( 10 19 Pa s) to a thin asthenosphere of a low viscosity ( 10 12 Pa s). Provided that Io's volcanoes are induced by convective anomalies in the mantle, we find that more than 80% of Io's internal heat is transported by magmatic processes and that Io's upper mantle needs to be thicker than 50 km. Plain Language Summary: Jupiter's moon Io is covered by a large number of active volcanoes. The distribution of Io's volcanoes on the surface provides insights into the interior of the moon, such as the processes that transport the produced heat to Io's surface and whether the layer beneath Io's crust is partially molten. We assume that a combination of solid‐state movements in this upper mantle and the upward movement of less dense magma control the locations of Io's volcanoes. To evaluate which combinations of interior properties are best suited to explain Io's observed volcanism and the large‐scale variations of volcanoes per area, we develop a model that investigates the characteristics of Io's interior convection pattern. If Io's total number of volcanoes is related to the small‐scale characteristics of the temperature pattern in the mantle, our results suggest that a large part of Io's heat is transported by rising magma and that Io's upper mantle is thicker than 50 km. Key Points: We use Io's volcanic activity pattern to constrain the moon's mantle properties and convective dynamics Io's volcanic pattern agrees with anomalies arising in a tidally heated mantle with convective‐magmatic heat transport If Io's volcanoes are linked to convective anomalies, a magmatic‐dominated heat transport and an upper mantle thicker than 50 km are favored