Geophysics and the Search for Homer’s Ithaca

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An extract from the paper presented at SAGEEP 2009
Greg Hodges, Fugro Airborne Surveys, Mississauga, CA
David Kilcoyne, Fugro-Aperio, Wallingford, U.K.
Rod Eddies, Fugro-Aperio, Wallingford, U.K.
John R. Underhill, University of Edinburgh, Scotland, UK”

Ithaki, Cephalonia and PalikiIdentifying the location of the island of Ithaca, legendary home of Odysseus, has been a problem for historians for centuries.  The modern island of Ithaki, in the Ionian Sea, does not match the description in Homer’s epic poem.  It is the hypothesis of Robert Bittlestone, working with geologist John Underhill and classicist James Diggle, that the westernmost part of Cephalonia, the Paliki peninsula, was ancient Ithaca.  Their book, Odysseus Unbound: The Search for Homer’s Ithaca, gives a detailed description of the evidence supporting the hypothesis, and the story of its development.  There is one major sticking point:  Paliki is joined to the larger part of the island of Cephalonia, by an isthmus as much as 180m above sea-level.    Figure 1 shows a Landsat 7 image of the islands today, and the Thinia valley fills the isthmus between Paliki and the rest of Cephalonia.  The new hypothesis requires a channel through the isthmus, perhaps in the location shown in Figure 2.

 

Thinia valley with possible channel route.Ground, airborne and marine geophysical surveys are being used to study the potential for a channel under an area now largely covered by colluvium from the adjacent mountains.  Fugro’s airborne EM and magnetic data provide a regional overview of ground conductivity (Figure 3).  Ground EM, resistivity, gravity and refraction seismic surveys obtained by Fugro Aperio are being used to study the proposed channel zone in detail to determine the depth of fill and contours of the buried bedrock surface.  Marine seismic has been employed offshore by Fugro Oceansismica to analyze the drainage patterns at the low water levels of 3000 years ago.  High resolution airborne LIDAR mapping from Fugro’s Fli-Map provides detailed surficial information. All of these data sets are brought together to build a comprehensive geological model of the proposed channel area and to provide the ultimate test of the classical enigma.

 

Airborne Apparent Resistivity map (40kHz)  on topography

 

(The full paper was presented at the EAGE Near Surface meeting in Dublin – 26th to28th September 2009, for further information contact Steve Poulter, Fugro Engineering Services Ltd 0870 4021423).