Laboratory Study of Frictional Stability and Tidal Triggering in Ice Mixtures

Lead PI: Dr. Christine McCarthy

Unit Affiliation: Seismology, Geology and Tectonophysics, Lamont-Doherty Earth Observatory (LDEO)

December 2019 - December 2022
Project Type: Research

DESCRIPTION: This is a combined experimental and modeling project to better understand the dynamics of localized shear heating and frictional stability on faults of icy satellites under tidal loading conditions. Some models of heat production on icy satellites suggest that heating from shear friction on near surface faults can explain various surface features and observed high heat fluxes. However, models of localized shear heating assume constant or average shear velociites along faults and use constant friction coefficients, whereas actual faults are experiencing oscillatory tidal stressing. We will experimentally measure the time-varying frictional response of ice and relevant ice mixtures to cyclic loading using a custom, servo-hydraulic friction apparatus. We will additionally explore the role of melt in friction by using a second phase (sulfuric acid) that has a deep eutectic with ice and is predicted to be important for icy satellites. The proposed experiments will address dynamical processes (rupture propagation and tidal heating) that control the geophysical characteristics and surface morphologies of features on icy satellites as well as long-term heating rates and satellite evolution.