Ice melts when it is in contact with ocean waters that have temperatures above the in situ freezing point. The
product is a mixture of meltwater and seawater having properties intermediate between those of the two components.
Density is one of the properties that is affected, and this has important implications for how the meltinduced
changes are eventually manifested. Although the direct impact of melting is to cool and dilute the ocean,
subsequent convection can carry the products of melting to parts of the water column where they are comparatively
warm and salty. These principles are illustrated with a set of observations from the continental shelf of the
Amundsen Sea. Measurements made near a floating glacier are used to calculate the concentration of meltwater
in the water column. Concentrations approaching 2% are associated with comparatively high temperatures, low
dissolved oxygen concentrations, and negligible stable isotope anomalies. The impact of drifting icebergs on
the Southern Ocean is discussed. Over most of the area to the south of the Polar Front, melting effects a transfer
of heat from the Circumpolar Deep Water to the overlying winter water. The resultant net heat flux over the
entire area is small, but locally it may exceed 100 W m22.