Graham Island (Italian: Isola Ferdinandea; French: 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.
History
Early history Volcanic activity at Graham Island was first recorded during the First Punic War during the 3rd century BC. The island has appeared and disappeared four or five times since then. Several eruptions have been reported since the 17th century AD. The island is located in a volcanic area known as the Campi Flegrei del Mar di Sicilia (Phlegraean Fields of the Sea of Sicily), in between Sicily and Tunisia in the Mediterranean Sea. Many submarine volcanoes (seamounts) exist in the region, as well as some volcanic islands such as Pantelleria.
1831 appearance
Graham Island's most recent appearance as an island was in July 1831. The first reports of high seismic activity and/or eruptions occurred during a period spanning from 28 June to 10 July 1831. These reports came from the nearby town of Sciacca. On 28 June, the Royal Navy ships Britannia and Rapid were shaken by an earthquake between Sciacca and Pantelleria. On 4 July, an odour of sulfur spread through the town reportedly in such quantities that it blackened silver. On 12 July, Ferdinando Caronna, captain of the Psyche from Naples, reported seeing smoke coming out of the sea. On 13 July, a column of smoke was clearly seen from St. Domenico. The residents believed it to be a ferry on fire. On the same day, the brig Gustavo passed through the area, confirming a bubbling in the sea that the captain thought was a sea monster. Another ship reported dead fish floating in the water. By 17 July, a fully grown islet had formed enough to where Sicilian customs official Michele Fiorini was able to land there and to claim the island for the Kingdom of Sicily. He planted an oar there to claim the newly emerged island for the Kingdom of the Two Sicilies. The eruptions of 1831 resulted in the island increasing in size to about four square kilometres (1+1⁄2 sq mi). At its maximum (in July and August 1831), it was 4,800 m (15,700 ft) in circumference and 63 m (207 ft) in height. It sported two small lakes, the larger of which was 20 metres (66 ft) in circumference and 2 m (6 ft 7 in) in depth. In the months ahead, Graham Island eventually became the subject of a four-way dispute over its sovereignty:
On 2 August 1831, Humphrey Fleming Senhouse, the captain of the first rate Royal Navy ship of the line HMS St Vincent claimed the island for the British Crown and named it after Sir James Graham, the First Lord of the Admiralty, and planted their flag, the Union Jack. Although still only a couple of rocks, the Royal Navy thought it was very suitable as a base to control the traffic in the Mediterranean, as it was closer to the European continent than the island of Malta, a Crown Colony. Ferdinand, the ruler of the Two Sicilies, also realized its strategic significance, and dispatched the corvette Etna to claim the new land and dub it Ferdinandea in honour of King Ferdinand II. Nobles of the House of Bourbon reportedly planned to set up a holiday resort on its beaches. Spain also declared its territorial ambitions. Last on the scene was Constant Prévost, a co-founder of the French Geological Society, who compared the eruption to a bottle of champagne being uncorked. He named the island Julia, because it was born in July, and probably also in reference to France's July Monarchy. Diplomatic disputes over the island's status ensued. Some observers at the time wondered if a chain of mountains would spring up, linking Sicily to Tunisia and thus upsetting the geopolitics of the region. During the island's brief lifespan tourists began to travel to the island to see its two small lakes. None of these ideas came to fruition, however, as the island soon sank back beneath the waters. The island was composed of loose tephra, easily eroded by wave action, and when the eruptive episode ended it rapidly subsided, disappearing beneath the waves in January 1832, before the issue of its sovereignty could be resolved. By 17 December 1831, officials reported no trace of it. As dynamically as the seamount appeared, it disappeared, defusing the conflict with it. In August 1831, observers around the world reported a discolored sun in the sky, tinted blue, purple, or green. Researchers have attempted to discover what volcanic activity was responsible for the stratospheric discharge that caused the discoloration, with an early consensus that Babuyan Claro in the Philippines was the most likely source. Yet, later research has concluded there was no 1831 eruption at Babuyan Claro, and some have argued the smaller activity at Graham was the likely culprit. Even later research ruled out a larger 1831 eruption of the Zavaritski Caldera, as the phenomenon predominated in a limited geographic range and lasted only a month. Nat Turner, an enslaved preacher in Southampton County, Virginia, took the bluish-green sun as a divine sign to begin what became known as Nat Turner's slave rebellion.
Recent seismic activity
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