SPECTRAL and FOCAL PARAMETERS of NORTHERN CAUCASUSEARTHQUAKES

Dynamic sources parameters of 21 earthquakes of the North Caucasus for 2014 with КР=9.5–11.5, determined from 44 S-wave amplitude spectra are analyzed. Records of three regional digital seismic stations, “Anapa”, “Kislovodsk” and “Sochi”, located no more than 300 km from the sources are used. For the environment near these stations, the values of the frequency-dependent Q-factor, necessary for recalculating the station spectra to the focal ones, were obtained earlier by O.V. Pavlenko. In 2014, the majority of earthquakes studied were located in the Eastern Caucasus. The dependence between log M0 and КР for this zone was constructed using the data for 2010–2013. Compared to the similar equation for the entire Caucasus (Riznichenko et all., 1976), this dependence is in a good agreement with respect to the free term, but differs by the slope.

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SPECTRAL and FOCAL PARAMETERS of NORTHERN CAUCASUS EARTHQUAKES in 2015

Zemletriaseniia Severnoi Evrazii [Earthquakes in Northern Eurasia] ◽

10.35540/1818-6254.2021.24.23 ◽

2021 ◽

pp. 237-244

Author(s):

L. Malyanova ◽

I. Gabsatarova ◽

N. Ponomareva

Keyword(s):

Wave Amplitude ◽

Northern Caucasus ◽

Q Factor ◽

North Caucasus ◽

S Wave ◽

Frequency Dependent ◽

Seismic Stations ◽

The North ◽

Amplitude Spectra ◽

Focal Parameters

The dynamic sources parameters of 29 earthquakes of the North Caucasus for 2015 with KR=9.5–11.4, determined from 38 S-wave amplitude spectra are analyzed. Records of four regional digital seismic stations, “Anapa”, “Kislovodsk”, “Makhachkala” and “Sochi”, located no more than 300 km from the sources are used. For the environment near these stations, the values of the frequency-dependent Q-factor, necessary for recalculating the station spectra to the focal ones. In 2015, the majority of earthquakes studied were located in the Eastern Caucasus. The dependence between log M0 and KR for this zone was constructed using together with the data for 2010–2014.

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SPECTRAL and SOURCE EARTHQUAKE PARAMETERS on NORTHERN CAUCASUS

Zemletriaseniia Severnoi Evrazii [Earthquakes in Northern Eurasia] ◽

10.35540/1818-6254.2019.22.28 ◽

2019 ◽

pp. 311-319 ◽

Cited By ~ 2

Author(s):

L. Malyanova ◽

Irina Gabsatarova

Keyword(s):

Northern Caucasus ◽

Q Factor ◽

North Caucasus ◽

Earthquake Parameters ◽

World Average ◽

S Waves ◽

The North ◽

Amplitude Spectra ◽

Similar Equation ◽

Good Agreement

The dynamic parameters of of 18 earthquakes sources in the North Caucasus for 2013 with КР=10.0–12.9, determined from 64 amplitude spectra of S-waves are given. Records of three regional digital seismic sta-tions, “Anapa”, “Kislovodsk” and “Sochi” are used. They are located no more than 300 km from the sources. The records of the “Makhachkala” station were used in a test mode. For the environment near these stations, the values of the frequency-dependent Q-factor, necessary for recalculating the station spectra to the focal ones, were obtained earlier. In 2013, the largest number of studied earthquakes was located in the Eastern Caucasus. The dependence of log M0 and КР for this zone was established with use of the data ob-tained in 2010–2013. Compared to the similar equation of world average dependence (Riznichenko, 1976), our dependence is in a good agreement with it by the slope, but the free term exceeds the same in the world average dependence by almost two units.

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Earthquake relocation in the wester termination of the North Aegean Trough

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.16828 ◽

2018 ◽

Vol 40 (3) ◽

pp. 1091

Author(s):

Ch. K. Karamanos ◽

G. V. Karakostas ◽

E. E. Papadimitriou ◽

M. Sachpazi

Keyword(s):

Time Delays ◽

Seismic Waves ◽

S Wave ◽

Data Set ◽

Arrival Times ◽

Velocity Models ◽

The North ◽

North Aegean ◽

Focal Parameters ◽

Hypocentral Location

The area of North Aegean Trough exhibits complex tectonic characteristics as a consequence of the presence of complicated active structures. Exploitation of accurately determined earthquake data considerably contributes in the investigation of these structures and such accuracy is seeking through certain procedures. The determination of focal parameters of earthquakes that occurred in this area during 1964-2003 was performed by collecting all the available data for Ρ and S arrivals. After selecting the best solutions from an initial hypocentral location, 739 earthquakes were found that fulfilled certain criteria for the accuracy and used for further processing. The study area was divided in 16 sub regions and by the use of the HYPOINVERSE computer program, the travel time curves were constructed, and were used to define the velocity models for each one of them. For each sub region the time delays were calculated and used as time corrections in the arrival times of the seismic waves. The Vp/Vs ratio, necessary for S—wave velocity models, was calculated with two different methods and was found equal to 1.76. The velocity models and the time delays were used to relocate the events of the whole data set. The relocation resulted in significant improvement of the accuracy in the focal parameters determination.

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Numerical analysis on heat transfer and flow resistance performances of a heat exchanger with novel perforated wavy fins

Thermal Science ◽

10.2298/tsci210309255w ◽

2021 ◽

pp. 255-255

Author(s):

Xuexi Wang ◽

Feng Lin

Keyword(s):

Reynolds Number ◽

Nusselt Number ◽

Heat Exchanger ◽

Friction Factor ◽

Wave Amplitude ◽

Numerical Study ◽

Inlet Temperature ◽

S Wave ◽

Air Inlet ◽

Good Agreement

In this paper, the experimental and numerical study of thermo-hydraulic characteristics of perforated wavy fin heat exchanger and unperforated wavy fin heat exchanger were conducted. Firstly, the two kinds of fins were studied under different air inlet velocity and constant inlet temperature. The results show that Nusselt number increases with Reynolds number and friction factor decreases with Reynolds number. Then, the performance of the two kinds of fins is numerically analyzed, and the simulation results are in good agreement with the experimental data. On this basis, the influence of different perforated fin parameters (fin height H, fin pitch s, wave amplitude wa, perforation number n, perforation diameter d) on the thermal performance of wavy fin heat exchanger is discussed. It is indicated that friction factor and Nusselt number increase with increasing aperture, wave amplitude, fin pitch and perforation number or decreasing fin height under constant Reynolds number condition. Finally, the performance evaluation of heat exchangers with different parameters is carried out to obtain the best performance heat exchanger parameters, which can provide a reference for the design of the new wavy fin heat exchanger.

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