Campi Flegrei del Mar di Sicilia (Phlegraean Fields of the Sicily Sea) is composed of a group of submarine volcanoes SW of Sicily.  The volcanoes were constructed within a submarine depression about 1000 m deep in the Strait of Sicily between the SW coast of Sicily and the NE tip of Tunisia, forming submarine banks that are capped by cones that rise to near sea level.  Submarine eruptions were reported at the Giulia-Ferdinandeo and Pinne banks during the first Punic war (264-241 BC), and from the 17th to 20th centuries, sometimes producing ephemeral islands.  The 1831 eruption at Graham Island (also known as Graham Bank, Giulia-Ferdinandeo Bank,  or Ferdinandea Bank) produced an ephemeral island that was promptly claimed by the navies of France, Britain, Spain, and Italy.