Estimation of high-frequency attenuation parameter (kappa) for hard rock stations of Turkish strong motion network

Download
2021-2-12
Akgün, Atınç Özgün
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 calculate the zero-distance kappa value for the hard rock strong-motion stations operated by the Disaster and Emergency Presidency of Turkey (AFAD). For this purpose, 6463 recordings from 22 strong-motion stations with measured average shear wave velocities at the first 30 meters (VS30) higher than 740m/s and having at least 100 records have been analyzed. The slope of the decay in the S-wave portion of the FAS (kappa) at high frequencies is determined for a carefully selected and record-specific frequency range. Variation of the kappa with epicentral distance is evaluated to determine the median zero-distance kappa and its uncertainty for each recording station. Estimated median zero-distance kappa values vary between 0.01s to 0.06s and are consistent with the limited amount of previously published data. Only a weak correlation in median zero-distance kappa is observed with increasing VS30, and a rather large scatter in kappa for the same VS30 values is observed. More robust results might be attained by isolating the site amplification effects of weak surficial layers and subcategorization based on available geological and geographical information.

Suggestions

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...
Measurement of the ZZ production cross section and Z -> l(+)l(-)l '(+)l '(-) branching fraction in pp collisions at root s=13TeV
Khachatryan, V.; et. al. (Elsevier BV, 2016-12-01)
Four-lepton production in proton-proton collisions, pp -> (Z/gamma*)(Z/gamma*)-> l(+)l(-)l '(+)l '(-), where l,l '(-) = e or mu, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 2.6fb(-1). The ZZ production cross section, sigma(pp -> ZZ) = 14.6(-1.8)(+1.9)(stat)(-0.3)(+0.5) (syst) +/-0.2 (theo) +/-0.4 (lumi) pb, is measured for events with two opposite-sign, sameflavor lepton pairs produced in the mass region 60 l(+...
Calculation of the Brillouin frequencies close to phase transitions in NaNO2
Yurtseven, Hasan Hamit (2002-01-01)
We calculate here the Brillouin frequencies of the L-mode [010], [001] and [100] of NaNO2 for the phase transitions from the paraelectric phase to the sinusoidal anti-ferroelectric phase near the Neel temperature (T-N = 437.7 K) and to the ferroelectric phase near the critical temperature (T-c = 436.3 K) in this crystalline system. For calculating the frequencies, we use the thermal expansivity data for the phase regions considered, under the assumption that the mode Gruneisen parameter determined for each ...
Numerical evidence of spontaneous division of dissipative solitons in a planar gas discharge-semiconductor system
Rafatov, İsmail (AIP Publishing, 2019-09-01)
This work deals with the formation of patterns of spatially localized solitary objects in a planar semiconductor gas-discharge system with a high Ohmic electrode. These objects, known as dissipative solitons, are generated in this system in the form of self-organized current filaments, which develop from the homogeneous stationary state by the Turing bifurcation. The numerical model reveals, for the first time, evidence of spontaneous division of the current filaments in this system, similar to that observe...
Prospects of FMCW-based frequency diverse array radar
Cetiner, Ramazan; Cetintepe, Cagri; Demir, Şimşek; Hizal, Altunkan (2019-11-01)
The linear frequency modulated (LFM) frequency modulated continuous wave (FMCW)-based frequency diverse array (FDA) radar concept is investigated in detail. The radar operates as a linear pulsed FMCW/FDA in the transmission (TX) mode while it operates as a pulsed FMCW/phased array (PA) in the receiving mode. The issues such as low signal-to-noise ratio (SNR) of FDA, the time-angle scanning and time-range ambiguities are studied. It is shown that the local instantaneous frequency bandwidth is much smaller th...
Citation Formats
A. Ö. Akgün, “Estimation of high-frequency attenuation parameter (kappa) for hard rock stations of Turkish strong motion network,” M.S. - Master of Science, Middle East Technical University, 2021.