Rapid Formation of Clathrate Hydrate From Liquid Ethane and Water Ice on Titan

Research areas:
Year:
2020
Authors:
  • T. H. Vu
  • M. Choukroun
  • Christophe Sotin
  • V. Muñoz-Iglesias
  • H. E. Maynard-Casely
Journal:
Geophysical Research Letters
Volume:
47
Number:
4
Pages:
e2019GL086265
Month:
February
ISSN:
0094-8276
BibTex:
Abstract:
Abstract Liquid ethane is present in the lakes and seas observed on Titan's surface by the Cassini-Huygens mission. While interaction between liquid hydrocarbons and water ice is expected to result in the formation of clathrate hydrates, such reaction (and its kinetics) has not yet been demonstrated for cryogenic liquids under relevant planetary conditions. In this paper, we report the first experimental evidence for rapid formation of clathrates upon direct contact of liquid ethane with water ice at 1 bar using micro-Raman spectroscopy. Kinetics experiments conducted in the temperature range 150?173 K yield an activation energy of 14.8 {\textpm} 2.2 kJ/mol, which is suggestive of a diffusion-controlled mechanism for clathrate formation. This implies that a clathrate reservoir can form within seasonal time scales on Titan if liquid ethane comes into contact with a pre-existing icy bedrock, which may hold important implications for the structure and dynamics of Titan's crust and its global evolution.