Temperature, salinity, and dissolved-oxygen data from the deep waters of the Panama Basin suggest that water enters the Basin through a single pass near Ecuador and subsequently spreads to the north and west. The flow is blocked in places by subsills, and warming occurs through mixing and geothermal heating. The bottom water appears to have a residence time of about 175 years, and heat flow is believed to be important in the renewal process in the bottom water.
Laird, Norman P.. 1971. "Panama Basin deep water----properties and circulation." Journal of Marine Research 29, (3). https://elischolar.library.yale.edu/journal_of_marine_research/1215