Empedocles is a large underwater volcano

Volcano

2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

 located 40 km off the southern coast of Sicily

Sicily

Sicily is a region of Italy, and is the largest island in the Mediterranean Sea. Along with the surrounding minor islands, it constitutes an autonomous region of Italy, the Regione Autonoma Siciliana Sicily has a rich and unique culture, especially with regard to the arts, music, literature,...

 named after the Greek

Ancient Greece

Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...

 philosopher

Philosophy

Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...

 Empedocles

Empedocles

Empedocles was a Greek pre-Socratic philosopher and a citizen of Agrigentum, a Greek city in Sicily. Empedocles' philosophy is best known for being the originator of the cosmogenic theory of the four Classical elements...

 who believed that everything on Earth was made up of the four elements

Four elements

Four elements may refer to:* Classical elements, such as air, fire, earth and water* 4 Elements, an album by Chronic Future* Group 4 element, one of the chemical elements in Group 4 of the periodic table...

.

According to Giovanni Lanzafame, of Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

's National Institute of Geophysics and Volcanology, the volcanic structure is around 400 meters high, with a base 30 km long and 25 km wide. Located in the Campi Flegrei del Mar di Sicilia

Campi Flegrei Mar Sicilia

Campi Flegrei del Mar di Sicilia is a field of submarine volcanoes located south-west of Sicily. It includes the vent of Ferdinandea, otherwise known as Graham Island, which erupted and emerged above sea level in 1831, and encompasses a larger volcano known as Empedocles. The last recorded eruption...

 (Phlegraean Fields of the Strait of Sicily

Strait of Sicily

The Strait of Sicily is the strait between Sicily and Tunisia. It is about wide and divides the Tyrrhenian Sea and the western Mediterranean Sea from the eastern Mediterranean. Its maximum depth is ....

), Empedocles is composed of what was once believed to be separate volcanic centers, including Ferdinandea

Ferdinandea

Ferdinandea is a submerged volcanic island which forms part of the underwater volcano Empedocles, south of Sicily, and which is one of a number of submarine volcanoes known as the Campi Flegrei del Mar di Sicilia. Currently a seamount, eruptions have raised it above sea level several times...

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The volcano shows no sign of erupting in the near future. While the volcano's top is now 7 meters below sea level

Sea level

Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...

, it was once visible above the water. In 1831 Empedocles broke the surface and almost caused a major international incident when several countries tried to claim ownership of it. It disappeared into the water again five months later.