Graham Island (Mediterranean Sea)
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About
Graham Island (Isola Ferdinandea, Île Julia) is a submerged volcanic island in the Mediterranean Sea near Sicily. It forms the tip of the submarine volcano Empedocles, 30 km (19 mi) south of Sicily, which is one of a number of underwater volcanoes known as the Campi Flegrei del Mar di Sicilia. The island has emerged from sea level four times in recorded history. Seamount eruptions have raised it from the surface before erosion submerged it again. The last prominent appearance occurred in July 1831, when the island emerged above sea level for six months. During that time, a four-way dispute over the island's sovereignty arose, which remained unresolved. The island is still referenced on marine charts, as its top is only 6 metres (20 feet) short of breaking the surface; it thus becomes a potentially dangerous hidden obstacle for many seafaring vessels, whose keels most often run deeper than this. It is also a small shoal on which near-surface maritime creatures dwell.
Adapted from Wikipedia (CC BY-SA). Photography via Wikimedia Commons.