Depth hoares are large crystals occurring at the base of a snowpack that form from when uprising water vaporfreezes onto existing snow crystal. Depth hoares are sparkly large grains with facets that can be cup-shaped and that are up to 10 mm in diameter. Depth hoares are loose granules that run through fingers and that bond and adhere to each other poorly, highly increasing the risk for avalanches.
The formation of depth hoar in antarctic firn can cause isotopic changes in the accumulating ice. This can influence analysis of ice cores in scientific research
, extensive summary with animation of formation process