Density is lowest at the surface, where the water is warmest. As depth increases, there is
Q1. Density is lowest at the surface, where the water is warmest. As depth increases, there is
Answer: Pycnocline
Explanation: A pycnocline is the layer in the ocean where water density increases rapidly with depth, caused by changes in both temperature (thermocline) and salinity (halocline), acting as a barrier to vertical mixing.