“…We prefer to use the term ''debris-covered glacier" where geological evidence supports the presence of subsurface ice that is significantly in excess of pore space and that is demonstrably related to glacier formation (see Head et al, 2010). Evidence supporting debris-covered glaciers includes laterally continuous and converging flow textures and structures (Head et al, 2006a,b), large sublimation pits and unusual superposed craters (Kress and Head, 2008), sublimation polygon structures and their geometry (Marchant et al, 2002;Levy et al, 2006), topographic profiles (Li et al, 2005), detection of abundant subsurface ice by radar (Holt et al, 2008;Plaut et al, 2009) or seismic surveys (Shean et al, 2007b), and experimental and rheological considerations (Mangold and Allemand, 2001;Mangold, 2003;Swanger et al, 2010). We prefer to use the term ''rock glacier" where rocky viscous-flow features do not meet these criteria.…”