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It is widely known that seismic shear‐wave velocity is one of the most important parameters in site characterization studies. In some instances, it is necessary to determine shear‐wave velocity indirectly from common in situ tests, such as the cone penetration test. There are numerous earlier studies showing this possibility. In this study, the relation between shear‐wave velocity and subsoil geotechnical properties, e.g., cone‐tip resistance and sleeve friction from cone penetration test is reinvestigated in a study area located in Eskisehir, Turkey. New polynomial models are proposed for the correlation. A total of 437 samples extracted from 37 sites made of clay, sand, sand‐clay mixture, and miscellaneous soil types have been used. We compare our results involving polynomial fitting with earlier results of statistical correlation using power‐law or logarithmic relations between shear‐wave velocity and cone‐tip resistance or sleeve friction. The predicted values using our model are checked against the measured ones to evaluate the performance of the polynomial model. The results suggest that the newly proposed approach provides a means for recognizing more efficiently the patterns in the data and reliably predicting the shear‐wave velocity. Additionally, the sensitivity analysis reveals the influence of parameters and the contribution of each coefficient in the polynomial model. Cone penetration test cone‐tip resistance relates more strongly than sleeve friction to shear‐wave velocity. The intercept term in the polynomial is of primary importance in such correlation, for all soil types.

The magnetotelluric method has been employed to generate a geoelectrical model that will reveal the rich geological pattern and dynamic character of western and northwestern Anatolia, Turkey. Magnetotelluric data were collected from 53 sites along a profile of 290 km from the Dardanelles to the Alaş ehir Graben. Magnetotelluric data were in the range of 0.00055 Hz to 320 Hz. The models were obtained through 2-D joint inversion of transverse electric and transverse magnetic modes. Lateral changes in geoelectrical models are verified by using gravity and magnetic data. In addition, some of the seismological data presented here agree with proposed models that suggest a brittle-ductile structure boundary at a depth of 20 km. Generally speaking, a regional extensional regime caused reduction in the thickness of the crust and consequent uplift towards the south. The constructed model delineates the western part of the North Anatolian Fault Zone along the Biga Peninsula. The current patterns of volcanic activity on the Biga Peninsula and at Kula are related to conductive spots presented in the models. The border of the Go¨rdes Basin, located between the Izmir -Ankara suture zone and the Menderes Massif, is also well delineated. The North Anatolian Fault Zone presents a pattern in which density and susceptibility anomalies attain relatively high values. Fillings covering most of the surface have lower density and susceptibility values than those of underlying structures.