ISOW enters the eastern North Atlantic over the Iceland-Scotland Ridge through the Faeroe Bank Channel at a depth of 850 m, with some water flowing over the shallower Iceland-Faeroe Rise. ISOW has a low CFC concentrations and it has been estimated from these concentrations that ISOW resides behind the ridge for 45 years. As the water flows southward at the bottom of the channel, it entrains surrounding water of the eastern North Atlantic, and flows to the western North Atlantic through the Charlie-Gibbs Fracture Zone, entraining with LSW. This water is less dense than (DSOW) and lays above it as it flows cyclonically in the Irminger Basin.