WDC for Geophysics, Beijing(中国地球物理学科中心)
 
   

Author-submitted data information


ID 424
Title Single- and two-station Lg amplitude datasets and the resulting Lg attenuation model in and around the Anatolian Plateau
Creator Wei-Mou Zhu
Subject Seismic Lg amplitude, attenuation model, Anatolian Plateau
Publisher Xiukuan Zhao
Description To investigate broadband Lg-wave attenuation and upon which to study the mantle upwelling and plateau uplift in Anatolia, we collected 87,764 vertical-component seismograms recorded at 849 stations from 615 crustal earthquakes with magnitudes between 4.0 and 6.5 in and around the Anatolian Plateau between January 2000 and December 2020. The original data were downloaded from International Federation of Digital Seismograph Networks (https://www.fdsn.org). Both the single- and two-station Lg amplitudes can be used in Lg attenuation tomography to construct an Lg attenuation model in this region. To obtain the spectral Lg amplitudes, we captured the Lg waveforms within a group velocity window between 3.6 and 3.0 km/s and picked the pre-event noise before the first P-arrival within the same length window with the Lg waveform, then calculated the Fourier spectra for both the Lg-wave and the noise, sampled the spectral amplitudes, and corrected for the noise. To control the data quality, we considered both the pre-event and pre-Lg noises. The Lg spectra were dropped to exclude Lg-signals seriously affected by the background noise or coda waves of previous phases based on the signal-to-noise ratios (SNR) between Lg and pre-P noise less than 2 or the SNR between Lg and pre-Lg noise less than 1.0. The two-station Lg amplitude ratios were calculated for the roughly aligned triples of the event and station pair. The resulting single-station amplitudes and two-station amplitude ratios, as well as a constructed Lg attenuation model, were provided in this Data Repository.
Contributor Lian-Feng Zhao, Xiao-Bi Xie, Xi He, Lei Zhang, Zhen-Xing Yao
Date January 2000 - December 2020
Type The Lg amplitudes were sampled at 58 frequencies distributed log-evenly between 0.05 and 10.0 Hz, and thus the spectral Lg amplitude data were provided in 58 separate files, with each file corresponding to one frequency indicated by the double-digit number in the name of the file. The Lg attenuation model is a 3D dataset for Q values in longitude, latitude, and frequency.
Format All Lg amplitude data, including single-station amplitudes and two-station amplitude ratios, were stored in the ASCII sott.*.dat files. The correspondence between the frequency and the double-digit number can be looked up in the file ‘frequency.txt’. The sott.*.dat files consist of header lines and data lines. Zero value in the 5th column indicates that the current line is the header line for single-station data, with the first two columns being the longitude and latitude of the recorded event, 3rd column being the number of lines of the following data, and 4th column the sequence number of the recorded event. The header lines for single-station data are immediately followed by lines of single-station data, with the columns successively being the longitude and latitude of the recording station, Lg amplitude, geometric spreading term, the sequence number of the recording station, and the magnitude of the recorded event. Zero value in the 4th column indicates that the current line is the header line for two-station data, with the first two columns being the longitude and latitude of the recording station, 3rd column being the number of lines of the following data, and 4th column the sequence number of the recording station. The header lines for two-station data are immediately followed by lines of two-station data, with the columns successively being the longitude and latitude of the in-between station, the inter-station ratio of Lg amplitude, geometric spreading term, the sequence number of the in-between station, and the magnitude of the recorded event.
The Lg attenuation model in Anatolian Plateau was stored in the AP_QLg_model.txt file, with the columns successively being the longitude, latitude, frequency, and Q.
URL http://www.geophys.ac.cn/ArticleData/20220831Lg_Amplitude_data_AP.zip
DOI 10.12197/2022GA025
Source
Language eng
Relation
Coverage
Rights International Federation of Digital Seismograph Networks; Institute of Geology and Geophysics, Chinese Academy of Sciences