The North American Plate is primarily in a state of equilibrium rather than strictly growing or shrinking. Though tectonic plates constantly shift due to geological processes, the North American Plate’s boundaries play a crucial role in its overall size.
At divergent boundaries, like those found along the Mid-Atlantic Ridge, new crust is formed, which can contribute to the growth of surrounding plates. Conversely, at convergent boundaries, where the North American Plate interacts with other plates, such as the Pacific Plate, material can be subducted, leading to a loss in mass.
Overall, the balance between these processes suggests that while there may be localized growth or shrinking depending on geological events, the North American Plate remains relatively stable in size over long geological timescales.