The minimum area of a node is the default area of the node, which is the user defined minimum surface area or 12.566 square feet if the user does not define the surface area of the node. The surface area of a node is usually the half of the surface area of all of the connecting conduits but if the link is dry then the sum of all of the surface areas may be less than the default surface area. If you look at a scatter plot of the area versus the depth then you will see that it always has the minimum surface area.
