There is relatively cold and deep water current called Antarctic bottom water (AABW) that travels up along the western edge of the south Atlantic from Antarctica, but it is very salty, as when seawater freezes into ice it ‘salts out’ increasing the salinity of the remaining seawater. It is also relatively oxygen rich, which isn’t the norm for deep waters. This water mass is one of the densest there is, which is why it creeps along the bottom.

There is also the Antarctic intermediate water (AAIW), which is not very salty, and it is formed from Ekman transport processes around Antarctica (…and it’s formation seems to still be a big point of research)