Dergi makalesi Açık Erişim

Offshore/onshore correlation of the North-Anatolian fault deformations in the Western Sea of Marmara

2021    Vardar, Denizhan; Alp, Hakan; Demirel, Sinan; Aykurt Vardar, Hande; Alpar, Bedri

Newly collected high-resolution seismic reflection and magnetic data collected offshore of the Ganos Fault (NW Turkey) in the western Sea of Marmara, along the submerged portion of the North-Anatolian Fault, highlight the presence of a complex fault pattern. Based on these data, we propose a new tectonic model for this key region, connecting the onshore fault pattern to the transtensional basins of the deepest Sea of Marmara. According to this new model, three main faults control the deformation pattern of this region, fault SF1, a tectonic element that shapes the Tekirdag Basin, and fault SF2, which although not affecting the sea floor, is structurally related to SF1. Another fault we called SF3, connects the offshore to the Ganos fault onshore creating a transtensional pattern nearby the shelf. All such kinematic indicators witness an incipient activity, and a seismogenic potential that should be determined by a detailed mapping of both the surficial expression of fault at the seafloor, and the deformation pattern observed in the post-glacial sedimentary sequence. The active fault pattern detected nearby the coastal areas and their structural relationships with the Tekirdag basin show that it could be interpreted as a negative flower structure, which accommodates strain partitioning. This observation is crucial to seismic hazard assessments in this region that has been the site of destructive earthquakes in the recent and remote past.