2026-06-27T22:46:27Zhttps://docta.ucm.es/rest/oai/request
oai:docta.ucm.es:20.500.14352/493402023-08-28T15:20:56Zcom_20.500.14352_14col_20.500.14352_15
Docta Complutense author Ruiz Pérez, Javier author Álvarez Gómez, José Antonio author Tejero López, Rosa author Sánchez, Nieves 2023-06-20T09:23:57Z 2023-06-20T09:23:57Z 2007 0019-1035 10.1016/j.icarus.2007.03.015 https://hdl.handle.net/20.500.14352/49340 http://www.elsevier.com/locate/icarus Although it is mostly accepted that the lower part of the ice shell of Europa is actively convective, there is still much uncertainty about the flow mechanism dominating the rheology of this convective layer, which largely depends on the grain size of the ice. In this work, we examined thermal equilibrium states in a tidally heated and strained convective shell, for two rheologies sensitive to grain size, grain boundary sliding and diffusion creep. If we take a lower limit of 70 mWm−2 for the surface heat flow, according to some geological features observed, the ice grain size should be less than 2 or 0.2 mm for grain boundary sliding or diffusion creep respectively. If in addition the thickness of the ice shell is constrained to a few tens of kilometers and it is assumed that the thickness of the convective layer is related to lenticulae spacing, then grain sizes between 0.2 and 2 mm for grain boundary sliding, and between 0.1 and 0.2 mm for diffusion creep are obtained. Also, local convective layer thicknesses deduced from lenticulae spacing are more similar to those here derived for grain boundary sliding. Our results thus favor grain boundary sliding as the dominant rheology for the water ice in Europa’s convective layer, since this flow mechanism is able to satisfy the imposed constraints for a wider range of grain sizes. eng Heat flow and thickness of a convective ice shell on Europa for grain size-dependent rheologies journal article URL https://docta.ucm.es/bitstreams/3dfdecc3-50eb-4d8e-96a9-df1eeb36086f/download File MD5 bd50f6c30d49ea0a715f4e092b62d693 967602 application/pdf 21-Europa_7.pdf