Tectonic and structural characteristics of Erzurum and its surroundings (Eastern Turkey): a detailed comparison between different geophysical parameters

Abstract

The tectonic and structural properties of Erzurum and its surroundings have been investigated by evaluating the seismo-tectonic b-value, magnetic anomaly, edge detection analysis (total horizontal derivative (THDR) and tilt angle (TA)), Curie Point Depth (CPD), P-wave velocity (Vp), and Vp / Vs (S-wave velocity) ratio and by imaging the regional distributions of these parameters. For this purpose, all parameters have been combined to be able to reveal the new useful results on the study region and are presented for different locations and depths. The Vp values have been accompanied by high Vp / Vs ratios and shallow CPD values in the areas with geothermal regions such as Tekman, Söylemez, and the northern part of Karlıova. In the tectonically active regions such as Ilıca, Dumlu, Pasinler, Çat, Karlıova and Karaçoban, high reduction-to – the-pole (RTP) total magnetic anomaly was accompanied by low Vp values in harmony. Besides, the low Vp values between 0 and 10 km and high b-values can be related to the weakness zones and the areas in which earthquake hazards are high in the study area. The low Vp values in the 0 km horizontal slice are in accordance with the high RTP total magnetic anomaly values in the triangle area between Aşkale, Ilıca-Dumlu-Pasinler, Narman, and Karaçoban. Uniformly, high Vp and low RTP total magnetic anomaly inclusions overlap in Çat and Tekman. In some regions such as Dumlu, Narman, Horasan, Karaçoban and south of Karlıova, the tilt angle values are positive (positive values in the tilt angle map correspond to the center of the structure causing the magnetic anomaly) and the Vp values are low, but there is not a complete harmony between these parameters. These results show that variations on these parameters are related to each other, and these types of geophysical data are required for tectonic and structural features at different locations and depth levels. © TÜBİTAK.