The ocean bulges outward and inward due to what feature of the ocean floor?

The ocean bulges outward and inward primarily due to bathymetry, which refers to the underwater topography of the ocean floor. Bathymetry influences how water is distributed in the ocean and interacts with gravitational forces, particularly from the moon and the sun. Coastal regions can experience significant changes in water levels due to this ocean floor topography, leading to variations in tidal ranges.

When the ocean floor has varying features such as underwater mountains, valleys, and continental shelves, these variations can cause water to be pushed higher or lower, creating bulges corresponding with the shape and structure of the sea bed. Areas where the bathymetry has shallower or steep gradients can influence the water's response to tidal forces, contributing to the tidal bulges observed.

On the other hand, currents, salinity, and temperature play important roles in ocean dynamics and can affect water density and circulation, but they do not directly cause the distinct outward and inward bulges associated with tidal movements. Thus, bathymetry is the key factor in understanding how the ocean's physical structure contributes to these bulges.