Today's islands of Ithaca and Cephalonia lie to the west of Greece, between Lefkas to the north and Zacynthos to the south. Although Ithaca is described as an island in the Odyssey, Homer’s Cephallenians are the people who live there in the Iliad:
Odysseus led the gallant Cephallenians,
From Ithaca and leaf-quivering Neriton,
When Odysseus makes himself known to King Alcinoos on the island of Scherie (thought to be Corfu) he introduces his homeland with a description that scholars have pondered over for many centuries:
I am Odysseus, Laertes' son, world-famed
For stratagems: my name has reached the heavens.
Bright Ithaca is my home: it has a mountain,
Leaf-quivering Neriton, far visible.
Around are many islands, close to each other,
Doulichion and Same and wooded Zacynthos.
Ithaca itself lies low, furthest to sea
Towards dusk; the rest, apart, face dawn and sun.
However today's island of Ithaca is not low-lying, it is mountainous. It is clearly not the furthest out to sea and it does not face towards dusk (i.e. west), nor do the adjacent islands face towards the dawn and sun (i.e. east). The geographical layout is almost opposite to that described by Homer, so how can his description of ancient Ithaca make any sense? And where are Same and the lost island of Doulichion?
Geology provides a vital clue. The Ionian Islands are located in one of the most tectonically active places in the world, where the African continental plate impacts that of Eurasia. Ten kilometres to the west of Cephalonia the seabed drops from a depth of 300 metres to an incredible 3 kilometres. Every month or so the ground shakes and every few decades there is a major earthquake: the last such event to impact the population was in August 1953.
But can earthquakes change the layout of entire islands? That was the challenge facing the exploration team in 2003. It has taken intensive efforts and the advice of experts from all over the world to answer this question. We now know that the answer is a resounding 'yes'.