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Geography & Geology

Ikaria is one of the largest islands in the eastern Aegean Sea and has a surface of approximately 270 km2 and almost 160 km is the coastline. Located East of Mykonos and  West of Samos, in North latitude 37 ° 40'40'' and East Longitude 26 ° 21'55.

Between Ikaria and Samos there is a sea channel of about 18 km width. To the south lies the complex of small islands Fournoi.  The administration of Ikaria belongs to the Region of North Aegean, while the island forms the Municipality Ikaria, with its capital the village of Agios Kirikos. The population is estimated at 8,423 inhabitants, according to the census of 2011.

Ikaria has an elongated shape with a NE-SW direction. Generally characterized as a mountainous island, with several intense geomorphic contrasts between bare cliffs and green valleys. Crossed by the sierra Atheras (or ‘ Pramnos’ ) of EW direction located at the center of the island and the highest peak is about 1,041 meters.

Mountainous are most of the villages on the island, with characteristics and features that have emerged throughout history and have been the lightened spot of its culture.

Coastal shores are generally narrow, with a horizontal division and very few gulfs, no notable bays and natural harbors. The bathymetry also the island presents many asymmetries, which reaches more than 1,000 meters deep in North Ikaria and decreases to the south. So the Ikcarian Sea, combined is one of the most difficult and dangerous seas of Greece.

The climate is characterized as relatively mild, of Mediterranean coastal type, with a lot of rainfall in winter and hot and drought during  the summer.

Characteristic of Ikaria, are strong winds acting throughout the year and especially during the summer, which often give a relief and freshness to visitors. Ikaria has an extensive river network, rich vegetation, biodiversity and abundance of water.

Significant number of habitats live on the island and many areas are protected by national and international contracts . Finally, it should be noted that due to intense geomorphology, often during the winter, are numerous landslides.

Geological Setting

Ikaria is a place with a very rich geoinheritance. The geology of the island provokes a particular interest, both for scientific and aesthetic reasons, which makes it an attractive destination for Geotourism.

It includes a variety of impressive rock formations, particular landforms, characteristic tectonic structures and wealth of minerals and fossils. A great abundance of waters in the island, retains alive a unique biodiversity.

Ikaria is a charming Geotope, that will give you knowledge and experiences!

Take the amazing Geotrails of the island on foot or with a bike and discover its wild natural beauty!

For this reason, it is worthwhile to make a detailed reference to the geological structure of the island.

Ikaria, along with Samos and Fournoi belong, according to recent studies,to the eastern part of the Attic - Cycladic mass. Primarily consists of crystall-schists, or semi-metamorphic and metamorphic rocks. These rocks include gneiss, schists, marble and various granite.
More specifically, three geotectonic units that construct Ikaria :

a) Lower section (or ‘Ikaria unit’) consisting of a background of gneiss, which comprises of ortho-gneiss, para-gneiss, where a formation of marble-schist is developed. Above the background meta-sedimentary rocks are developed, similar to the lower section of the Cyclades and Pelagonian zone of the mainland. Within these metamorphic rocks have penetrated during Miocene, the granites of Raches in the West and of Xylosyrtis in the East . Characteristic formations of this unit are: the formation Petropouli, the dolomite Punda, the Upper Marble Punda , the gneiss of Plagia and Lower Marble ‘Nicaris’.

b) The Intermediate Unit (or Unity ‘Messarias’) includes marbles and phyllites. The module associated with the unit ‘Dris’ ( south Paros ) because of a similar degree of matamorphosis and the type of rock which overlies (amphibolite phase). The 'unity Messaria' is tectonically located on the 'unity Ikaria'

c) The above tectonic unity (or unit ‘Kefala’) comprises molassic ophiolitic formations, which are dragging with them recrystallised white limestones, like the ones found in  Kefala hill (central part of the island). The upper tectonic unit ‘Kefala’ is a tectonic window area of ​​1,5 km2. Based on mineralogical examinations, conditions of low pressure and high temperature were appeared.

Younger formations of Neogene (such as conglomerates, sandstones and clay complete geological picture of the island.

Sedimentary rocks in Ikaria are minimal. Tectonically, Ikaria is described by 4 main deforming phases.

The Western part of the island consists of granite, similar to the granite Naxos and Mykonos. Its age is placed in Lower Miocene and constitutes the largest plutonium body Aegean.
The Eastern part of the island consists of gneiss, muscovite schist, marble and semi-metamorphic schists. The rocks of the eastern part are separated from the western part by a large granite vein.

Some of the main minerals of the rocks of Ikaria are limonite, emery, andalusite, sillimanite, tourmaline, biotite, titanite, ilmenite, hematite, rutile, zirconium, corundum and other.

Landslides are very common in Ikaria, mostly due to the gelogical structure of the island, the action of various tectonic forces, the geomorphological evolution, the vegetation cover, the high rainfall and human intervention.

Such phenomena have significant economic and social impact on the island, since every year roads are destroyed, thus the communication between the villages is cut of and homes and lives are affected. Landslides are a significant natural disaster on the island of Ikaria, which must be taken into consideration in order protection of its development.

Water resources

Ikaria is as an island with a great volume of water. Due to the geological and tectonic structure, the island has rich aquifers and many springs. There are about 65 springs that are used for water supply and 290 springs that are used for irrigation. Almost all the villages have their own springs, nevertheless there is an important number of drillings on the island. The abundance of groundwater, combined with the tectonic structure has created many caves,  which are well worth visiting.

Surface water runoff is great and the sustainable management of this water have been realized by several reservoirs:

- The dam at Pezi, built in 1995, with a net capacity of 1,000,000 cubic meters, powered by the stream Pezi and used to cover needs and irrigation in the area of Raches.
- The reservoir in Christos in Agios Kirikos, built in 2001, has a capacity of 80,000 cubic meters and is used for water supply and irrigation in the area of Agios Kirikos.
- The construction of small reservoirs is planned in the areas Lydi, Kyparissi, Kouniadoi and Laggada and two dams in Perdiki and Therma, which will contribute significantly to the exploitation of the water resources of Ikaria.


The Hybrid Energy Project of Ikaria, which is implemented on the island today, is an innovative energy project development, both for local and European community, with significant benefits for the local community and the environment. So, Ikaria will attracts numerous visitors, scientists and non-scientists, who wish to face this innovative project.

This project will produce clean energy, which would solve the energy needs of Ikaria for decades. The net annual energy production of the Hybrid Energy Project will reaches 10,96 GWh, significantly reducing the need for local operation of the thermal power plant in Agios Kirykos.
Based on the innovative combination of two different forms of renewable energy:

  • wind
  • hydropower

The project began in May 2009 and completed in 2017 (but still not working).
The Hybrid Energy Project Ikaria consists of :

  • The existing reservoir capacity in Pezi of 900000 m3 of water.
  • Two tanks of water saving capacity of 80000 m3 each, in Proespera and Lower Proespera.
  • Two small hydropower stations with turbines (total capacity of 4.15MW) in Proespera and Lower Proespera.
  • Pumping of 2 MW power for lifting water from the bottom to the upper tank.
  • Underground pipeline inlet and outlet water length 5.5 km.
  • Wind farm with three turbines total capacity of 2.7 MW, in the "Stravokountouras" in Raches, with future placement 4 others in place Perdiki total capacity of 1.8 MW
  • Control Center in the existing local station of Agios Kirykos, who will be upgraded.

The process of generating electricity from the hybrid project is as follows:
The hydropower station of Proespera rated at 1.05 MW, exploits the existing reservoir overflows (location Pezi) to produce energy. The water exiting from the first initiation fills the adjacent upper reservoir. Then directed to the station of  Lower Proespera, power 3.1 MW, which is used to produce additional energy and results in the second row, the lower tank. The wind farm with a total capacity 2.7 MW, produces energy being fed into the grid and in pumping station, where it is used to transport water from the lower to the upper reservoir and re- generation of the hydropower station in Lower Proespera.