Predictive kappa (kappa) models for Turkey: Regional effects and uncertainty analysis

Date

2022-11-01

Author

Altindal, Abdullah
Askan Gündoğan, Ayşegül

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

145
views

0
downloads

High-frequency attenuation of ground motions is commonly characterized by the kappa parameter. kappa and its value at zero distance, kappa(0), are critical parameters for site characterization, ground motion simulations, and adjustment of ground motion models for different site conditions. In this study, we derive regional kappa models for Eastern, Western, and Northwestern Turkey, using a ground motion data set of 3212 strong ground motion records with 9636 components from 1053 earthquakes, recorded at 178 stations with varying site conditions. Initially, models with linear functional forms are derived with distance and site conditions as predictor variables. Residual analyses showed that these models have non-normal residuals with heterogeneous variances (heteroscedasticity). Box-Cox transformations on kappa values are performed to address these two issues. Models using these transformations resulted in normal residuals with homogeneous variances (homoscedasticity). Effects of earthquake magnitude on the kappa value are also investigated, and a linear adjustment for magnitudes is proposed. A constant vertical-to-horizontal ratio of 0.78 is proposed to estimate the vertical kappa values instead of deriving separate models for the vertical component. This approach does not result in significant decreases in accuracy and is preferred due to its simplicity. Next, the physical implications of logarithmic transformations for the kappa values are discussed. Finally, regional differences in kappa models are highlighted.

Subject Keywords

Kappa (kappa), regional kappa (kappa) models, high-frequency decay, Box-Cox transformation, residual analysis, STRONG-MOTION ACCELERATIONS, SPECTRAL DECAY PARAMETER, ATTENUATION, ROCK, DISTANCE

URI

https://hdl.handle.net/11511/100354

Journal

EARTHQUAKE SPECTRA

DOI

https://doi.org/10.1177/87552930221116651

Collections

Department of Civil Engineering, Article

Suggestions

OpenMETU
Core

Estimation of high-frequency attenuation parameter (kappa) for hard rock stations of Turkish strong motion network Akgün, Atınç Özgün; Gülerce, Zeynep; Özacar, Atilla Arda; Department of Civil Engineering (2021-2-12) Site-specific decay in the Fourier Amplitude Spectrum (FAS) at high frequencies, a.k.a. the zero-distance kappa (κ0), is frequently used in seismic analysis of critical infrastructure; especially for the host-to-target adjustment of the design spectrum and the site response analysis. The zero-distance kappa value for hard rock sites is more crucial but harder to constrain because the amount of strong-motion stations on hardrock sites is limited in the global datasets. The objective of this study is to calcu...
A regional near-surface high frequency spectral attenuation (kappa) model for northwestern Turkey Askan Gündoğan, Ayşegül; Pekcan, Onur (2014-10-01) One approach to model the high-frequency attenuation of spectral amplitudes of S-waves is to express the observed exponential decay in terms of Kappa (kappa) factor [1]. Kappa is a significant parameter used for identifying the high-frequency attenuation behavior of ground motions as well as one of the key parameters for stochastic strong ground motion simulation method. As of now, there is not a systematic investigation of the Kappa parameter based on the recently-compiled Turkish ground motions. In this s...
Uncertainty in Nonlinear SDoF Response Due to Long-Period Noise of Accelerograms Akkar, Dede Sinan; Guelkan, Polat; Kale, Oezkan (2009-07-01) The behavior of nonlinear oscillator deformations due to the long-period noise in strong ground motions is investigated. Inelastic spectral and residual displacements (SDIE and SDR, respectively) are selected to represent the nonlinear deformations of single-degree-of-freedom (SDoF) systems. Within this context, the interaction between these deformation demand parameters and high-pass filtering that is used for removing the long-period noise is examined. Analyses indicate that the high-pass filter values ca...
Preliminary Estimation of Kappa Parameter in Croatia Stanko, Davor; Markusic, Snjezana; Ivancic, Ines; Mario, Gazdek; Gülerce, Zeynep (IOP Publishing; 2017-09-15) Spectral parameter kappa  is used to describe spectral amplitude decay “crash syndrome” at high frequencies. The purpose of this research is to estimate spectral parameter kappa for the first time in Croatia based on small and moderate earthquakes. Recordings of local earthquakes with magnitudes higher than 3, epicentre distances less than 150 km, and focal depths less than 30 km from seismological stations in Croatia are used. The value of kappa was estimated from the acceleration amplitude spectrum of sh...
Performance of IRI-based ionospheric critical frequency calculations with reference to forecasting ÜNAL, İBRAHİM; Senalp, Erdem Turker; YEŞİL, ALİ; Tulunay, Ersin; Tulunay, Yurdanur (American Geophysical Union (AGU), 2011-01-27) Ionospheric critical frequency (foF2) is an important ionospheric parameter in telecommunication. Ionospheric processes are highly nonlinear and time varying. Thus, mathematical modeling based on physical principles is extremely difficult if not impossible. The authors forecast foF2 values by using neural networks and, in parallel, they calculate foF2 values based on the IRI model. The foF2 values were forecast 1 h in advance by using the Middle East Technical University Neural Network model (METU-NN) and t...

Citation Formats

A. Altindal and A. Askan Gündoğan, “Predictive kappa (kappa) models for Turkey: Regional effects and uncertainty analysis,” EARTHQUAKE SPECTRA, vol. 38, no. 4, pp. 2479–2499, 2022, Accessed: 00, 2022. [Online]. Available: https://hdl.handle.net/11511/100354.