Gibbs himself considered the following problem that arises if the ideal gas entropy is not extensive. Two identical containers of an ideal gas sit side-by-side. There is a certain amount of entropy S associated with each container of gas, and this depends on the volume of each container.
The intertidal zone is the area of the ocean between the high tide and low tide lines, usually on the beach at the water's edge. If you think of the line created at high tide as the upper limit and the line created at low tide as the lower limit, the intertidal zone is everything between those lines.
By Jennifer Kennedy. Pelagic Zone Background: The open ocean, or pelagic zone, is the area of the ocean outside of coastal areas, and where youâll find some of the biggest marine life species. The sea floor (demersal zone) is not included in the pelagic zone. Different Zones in the Open Ocean: The pelagic zone is separated into several subzones depending on water depth: 1  Epipelagic zone (ocean surface to 200 meters deep).