Deep Water Exchange Through Fracture Zones In The North Atlantic Ridge, Central Atlantic

The study investigates the properties of deep and bottom waters in four previously unexplored fracture zones of the Mid-Atlantic Ridge located between 24° N and 36° N. Based on new field data, the spatial variability of thermohaline and hydrochemical structures in each of the fracture zones was studied. In the meridional direction, a decrease in oxygen and temperature and an increase in the concentrations of nutrients from north to south on both sides of the Mid-Atlantic Ridge have been confirmed. The absence of bottom water flow from the Eastern Atlantic to the Western Atlantic was shown to be mainly due to the large number of orographic obstacles within the fracture zones and the positive horizontal density gradient. The presence of deep water exchange between different parts of the Atlantic in all fracture zones was established. In the northern fracture zones, the flow is directed mainly westward at depths of 2200-2800 m, while in the southern fracture zones, eastward transport prevails at depths of 3100-4400 m. Thus, deep waters are renewed within the fracture zones and transported across the Mid-Atlantic Ridge.