«What the situation suggests for Greenland ice melt summer 2016 is some thermal erosion of the «cold content» of the snow overlying the ice sheet, meaning less heat needed to «ripen'the snow to the melting point,» Box said. (washingtonpost.com)
Pressure of overlying ice, causes a change below 50m and brittle ice becomes plastic and begins to flow. (drtimball.com)
However, we caution that these results do not imply that the ice formation problem is solved because several unique conditions favored agreement between simulated and observed ice crystal number concentrations in this case: overlying ice nucleus concentrations much greater than in - cloud ice crystal concentrations, very slow - falling ice crystals, and the possible presence of an ice nucleus reservoir below a decoupled surface layer. (giss.nasa.gov)