Evaluation of the Relative Tectonic Activity in the Eastern Lake Van Basin, East Turkey

Abstract

The eastern part of the Lake Van basin (Van region, Turkey) is controlled by reverse faults, such as the Gurpinar, Everek and Alakoy faults. These represent the major tectonic structures within the Van region and have caused many devastating earthquakes. Based on quantitative analyses, the Quaternary activity and topographic relief control of each of these faults was investigated. The Gurpinar, Everek and Alakoy faults are restricted to the southern slopes of the Guzelsu, Everek, and Karasu basins, respectively. Analyses of the mountain front sinuosity (S-mf) and valley floor width-to-height ratio (V-f) suggest high activity along the Gurpinar fault, the Everek fault, and the western part of the Alakoy fault. Furthermore, based on the integration between S-mf and V-f, the estimated uplift rates were observed to increase from north to south. The Gurpinar and Everek hanging-wall blocks are characterized by uplift rates of >0.5 mm yr(-1), whereas the Alakoy fault exhibited a rate of 0.05 to 0.5 mm yr(-1). These faults produce knickpoints or knickzones, complex basin hypsometric curves, and high values of the stream length-gradient index. Based on these geomorphic analyses, it was established that the tectonic activity of both the Gurpinar and Everek faults is greater than that of the Alakoy fault. (C) 2016 Published by Elsevier B.V.