A Regional High-frequency Attenuation (Kappa) Model for Northwestern Turkey

The high-frequency attenuation of spectral amplitudes of S-waves is modeled as an exponential decay in terms of Kappa factor (Anderson and Hough, 1984). It is thus an important parameter of soils identifying the high-frequency attenuation behavior of ground motion as well as one of the key parameters for stochastic strong ground motion simulation method. In particular, for regions with sparse seismic networks, it is crucial to use simulated ground motions which require well-defined regional seismic parameters. Several stochastic simulations have been made for recent earthquakes occurred in Turkey; however there is not yet a systematic investigation of the Kappa parameter from the recently recorded Turkish ground motions. In this study, we examine a strong ground motion dataset from Northwestern Turkey with varying source properties, site classes and epicentral distances. We manually define Kappa from the S-wave portion of each record. We use both traditional regression techniques and data mining approaches to describe the (potential) relationships between Kappa values and independent variables such as the site class, distance from the source or magnitude of the event. Unlike the classical methods, data mining techniques provide a deeper insight to the problem through data analytics, in which a better understanding of existing patterns of data results in higher prediction performances. We then compare the outcomes of data mining techniques with those of traditional methods to better highlight the important characteristics of the ground motion dataset. We express the initial findings of a regional Kappa model for Northwestern Turkey with focus on magnitude, site class and distance dependencies. The Long Beach Seismic Experiment: A Novel High-Density Array to Examine Seismic Scattering
Citation Formats
F. N. Şişman, O. Pekcan, and A. Askan Gündoğan, “A Regional High-frequency Attenuation (Kappa) Model for Northwestern Turkey,” presented at the SSA, 2012 Seismological Society of America Annual Meeting, (17 - 19 Nisan 2012), 2012, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/78988.