The Larsos fault, with E-W direction, is one of the active faults of Lesvos. It is evidence of the recent geological changes that shaped the current form of the relief of Lesvos by forming the marshy areas of the Evergetoulas river delta.
Faults are created when the stresses developed in the rocks of the earth’s crust exceed the strength limit of the rock, causing them to break. In this way, a relative movement and displacement of the two pieces of the crust, on either side of the fault surface, is created.
The faults create a strong morphological relief on the surface of the earth and appear as steep morphological surfaces on which the smoothed, by friction, surface of the fault can often be distinguished.
Characteristic is the steep morphological terrace and the impressive mirror surface of the Larsos fault, with smoothed surfaces on which the traces of the tectonic slip of the submerged piece have been engraved. These are characteristic lines (marks) that show the direction of the relative movement of the two blocks that moved due to the seismic activity in the area.
The fault of Larsos was created when the section on which the road axis Mytilini – Kalloni passes today, came down in relation to the other one, which is today the characteristic hill “cut” by the fault, of the area.
Recently, the Ephorate of Antiquities of Lesbos has discovered archaeological evidence in the area, possibly linked to a strong earthquake that took place in the area during the 8th century BC.
During the Roman period, a water transport channel was carved on the surface of the Larsos rift, which is part of the 27 km long Roman aqueduct that starts from the outskirts of Mount Olympus and carried water for the water supply of Mytilene.
