Bottom Melting or Undermelt (Ice Shelf)

The basal melting of a snowpack or a glacier is termed as bottom melting. This term often related with glacier ablation, or under-melt for sea ice (Menzies, 1995). Various convective phenomena are responsible for the bottom melting which mainly depends upon the bulk temperature and velocity of the water and for the sea ice, would be salinity. The addition of sensible heat can cause the internal melting of the ice cover which could be added to the ice through conduction or radiative process. The overall effect of heat flux is to raise the bulk temperature of the ice to the point where preferential melting begins. The presence of snow at the upper surface may affect the process and magnitude of the bottom melting as it diverges the heat transfer to the underlying ice layers (Lock, 1990).

The process of melting initiates at the vicinity of impurities and the grain boundaries. The effect of impurities following the melting can be seen as rotten ice which is a reflection of granular...