Continent continent. From this perspective, the edge of the continental shelf is the true edge of the continent, as shorelines vary with changes in sea level. In this sense the islands of Great Britain and Ireland are part of Europe, while Australia and the island of New Guinea together form a continent. As a cultural construct, the concept of a continent may go beyond the continental shelf to include oceanic islands and continental fragments. In this way, Iceland is considered part of Europe and Madagascar part of Africa. Extrapolating the concept to its extreme, some geographers group the Australian continental plate
Continent periphery of the North American Plate, is sometimes referred to as a subcontinent. This is a significant departure from the more conventional view of a subcontinent as comprising a very large peninsula on the fringe of a continent. Where the Americas are viewed as a single continent (America), it is divided into two subcontinents (North America and South America) or three (with Central America being the third). When Eurasia is regarded as a single continent, Europe is treated as a subcontinent. Some areas of continental crust are largely covered by the sea and may be considered submerged continents. Notable examples