THE ISLE OF ISCHIA

The isle of ischia

geological story

Morphology

Description of Ischia

The island of Ischia is known as the "Green Isle" due to the colour of the surrounding sea, the island's interior and the predominant green tuffaceous rock and its vigorous vegetation. The mountainous island's main peak,the Epomeo is formed from volcanic rock and soars 788 metres above the sea. The Epomeo is the highest point of the crater rim although it has been partially destroyed through erosion that stretches from Serrara through Fontana and ends at Barano. The main features on the crest going towards Serrara are Pietra del Canterella, Pietra dell'Acqua and Frassitella. Going towards Barano the Montagna Bianca (768m), Ciglioni, Letto, Turatela, Tippodi and the Monte del Bianchetto Spur (721m) line the route. The magnificent view from the top of the Epomeo covers the whole island and the surrounding deep blue sea. The panorama covers a radius of 180 kilometres including Ventotene (40 kms distance), the Pontine Islands, the Tyrrhenian coast from Monte Circeo, the Lepini, the Aurunci, the Gulf of Gaeta, the Mount Massico, the Monte di Roccamofina, the Matese, the Flegrei, the Monte Taburno, Vesuvius and the Gulf of Naples, the Monti Lattari and the Sorrento coast, from Punta Campanella and Capri as far as the Monti del Cilento. Long, hot and dry summers followed by mild winters plus the extremely fertile volcanic soil create a perfect environment for Mediterranean shrubs and even for the sub-tropical and tropical plants found in various gardens and the botanical park.

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geological history

Roughly 10 million years ago the area that is now Italy and the islands of Corsica, Sardinia and Sicily was a single land mass. Since then a slow rotation to the East has bought the Italian peninsula to its present position forming the Tyrrhenian Sea basin. This movement, still on-going, ironed out the earth's crust and formed a series of deep cracks that encouraged the rise of magma towards the surface creating a series of volcanoes on the western coast of Tuscany and Lazio and the active volcanoes around Naples (Campi Flegrei, Ischia and Vesuvius)..


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morphology

From a morphological perspective Ischia is formed by a high central zone (Monte Epomeo) that is surrounded by numerous eruptive centres. The Monte Epomeo covers a surface area of 16.2 km² and represents 34,5% of the island's total surface. It is mainly made up of rock from volcanic origin plus sediments and volcanic deposits from further eruptions. The Epomeo is considered to be an elevated structure whose present position resulted from the elevation of a single block of volcanic rock. This movement, dating back 28,000 to 33,000 years ago, was probably caused by a dramatic increase of pressure within the magma chamber as new magma entered. The vertical pressure applied to the roof of the magma chamber elevated the block composed of the tuffaceous rock, plus rock from previous eruptions, creating deep cracks at the foot of the mountain. The Monte is surrounded by deep fractures that act as an escape route for gases and water heated in the depths. Fumaroles and whole areas emitting steam reaching temperatures near to 100°C can be found on the slopes of Monte Nuovo and Monte Cito as well as on the stretch of coast at Maronti. Fumaroles in other areas don't exceed 46°C., whilst temperatures of the hot springs go from 20° to 80°C. Earthquakes and eruptions have been frequent throughout the history of Ischia due to its geological make-up. A prehistoric settlement covered in volcanic ashes, with evidence of Iron Age tools, is located on a beach half way between Ischia Porto and Casamicciola. These Earthquakes and volcanic eruptions pushed the Greek colonies who founded Pithecusae in the 8th Century B.C. towards the mainland where they founded the community of Cuma. The Greeks abandoned the island permanently in 600 B.C. following the eruption of Monte Rotaro. In 486 B.C. Ischia was occupied by the Syracusans who again fled following another eruption sometime between 470 and 474. It is widely reputed that this is when the crater at Ischia Porto was formed. Following a long period of abandon the island was colonised by people from Neapolis, probably the same people who had left it centuries before to form the future city of Naples on the coast. Volcanic activity continued for most of the Roman period and there are reports of eruptions in 91 B.C. during the reign of Emperor Augustus, who exchanged Ischia for Capri with the city of Naples. The last eruption on Ischia was in 1302 when a crater opened in the Fiaino area disgorging lava for two months. The 100 to 500m wide flow of lava, once called Cremate and now known as Arso, reached the port at Ischia as well as Ischia Ponte destroying the ancient town centre of Geronda. The eruption resulted in the flight of lots of people to the mainland and surrounding islands. Among the numerous earthquakes on the island in the last couple of centuries the worst happened in 1881 and 1883. Since then the only noticeable volcanic activity are the active fumaroles. Notwithstanding this lack of activity, Ischia, just like the neighbouring Campi Flegrei and Vesuvius, is still considered to be an active volcano.

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