Identifying Fault Activity in the Central Evoikos Gulf (Greece)

Abstract

Geological mapping on a 1:5.000 scale and a tectonic analysis in the wider Chalkida region of the Island of Evia and the adjacent Drossia area of Central Greece, have allowed the identification of a number of active and potentially active normal faults. These faults have been formed or reactivated during the

Combination of Aerial, Satellite, and UAV Photogrammetry for Mapping the Diachronic Coastline Evolution: The Case of Lefkada Island

“…The first image of the specific dataset was collected during the CORONA KH-4B mission in May 1972 ( Table 2). The specific satellite collected the photographs with a telescopic camera, and the In addition to the CTFZ, the so-called Athani Fault is mapped onshore in the study area controlling the western Lefkada coast [66,67]. The Athani Fault is defined for almost 20 km, crossing lengthwise the west coast of Lefkada Island (Figure 2b).…”

Geomorphic Evolution of the Lilas River Fan Delta (Central Evia Island, Greece)

“…According to several seismotectonic studies in the broader area of the Evoikos Gulf, its Northern part is characterized by very pronounced faulting tectonics, associated with powerful destructive earthquakes [41][42][43]. In contrast, the Gulf's central and southern parts, where the Lilas River fan delta is located, are considered areas of mild tectonic activity and moderate seismicity [44,45]. There are no large tectonic structures in the vicinity of the central Evoikos Gulf and earthquakes are usually of low magnitude.…”

“…The northern margin of the South Evoikos Gulf is defined by the W.NW-E.SE directed Lefkandi normal fault. The fault dips to the south, continues offshore for a total length of 25 km, south of the modern towns of Eretria and Amarynthos [45,48] and affects the southeastern part of the Lilas River fan delta plain. The trace of the fault in the fan delta plain has been mapped in detail by Rondoyanni et al [45] using geophysical techniques.…”

“…The fault dips to the south, continues offshore for a total length of 25 km, south of the modern towns of Eretria and Amarynthos [45,48] and affects the southeastern part of the Lilas River fan delta plain. The trace of the fault in the fan delta plain has been mapped in detail by Rondoyanni et al [45] using geophysical techniques. An average fault slip rate of 1 mm/year for the last 150,000 years is estimated, which is significantly smaller than that of the faults delimiting the graben of the North Evoikos Gulf (3 mm/year) [49].…”

“…A smaller fault directed also W.NW-E.SE and dipping to the south outcrops near the village Vassiliko. It has a visible length of 5 km, whereas tectonic striations on the fault surface indicate a recent fault reactivation [45]. Water depths over the South Evoikos Gulf range from 20 to 68 m and the seafloor relief is characterized by low gradients (1:1000) [50].…”