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.
Background: The intertidal zone is the area where land and sea meet. This habitat is covered with water at high tide, and exposed to air at low tide. The land in this zone can be rocky, sandy or covered in mudflats. The intertidal zone is divided into several zones, starting near dry land with the splash zone, an area that is usually dry, and moving down to the littoral zone, which is usually underwater.