Figure F3. Position of Leg 172 BBOR sites with respect to water masses in the western subtropical North Atlantic. Water depths are indicated every 500 m along the temperature/salinity plot. Sites were chosen so that at least one lies within each modern water mass and one lies at the boundary between water masses. This depth distribution of sites is required to monitor the most likely changes in water masses and their boundaries through the late Neogene. KNORR 140/2 Hydro Sta. 1 refers to the site survey cruise and station number that were used to collect the data. "High-CFC" indicates the shallowest components of North Atlantic Deep Water (NADW) that originate in and near Labrador Sea and can be traced using chlorofluorcarbons. AABW = Antarctic Bottom Water (modified from fig. 3 in Shipboard Scientific Party, 1998a).