Author-submitted data information
| ID | 421 |
| Title | Single- and two-station Lg amplitude data in the South China Block (SCB) and the resulted broadband QLg model in this region |
| Creator | Lin Shen |
| Subject | Seismic Lg amplitude, QLg model |
| Publisher | Xiukuan Zhao |
| Description | To explore the crustal Lg-wave attenuation and its tectonic implications for the SCB, we collected the vertical components waveforms of 218 crustal earthquakes that occurred in the SCB and its surrounding regions over a time period between January 2000 and November 2018 with magnitudes between 3.5 and 6.0, which were recorded at 536 stations from the China National Digital Seismic Network (CNDSN) and 44 stations from the Incorporated Research Institutions for Seismology (IRIS). We performed an Lg attenuation tomography based on the single- and two-station Lg amplitude data. The Lg-wave signals were sampled using a group velocity window between 3.6 and 3.0 km/s from the vertical component broadband regional waveform data. A time window of the same length was applied before the first P-wave arrival and Lg-wave to sample the pre-event and pre-Lg noise series. A pre-event and pre-Lg signal-to-noise ratio (SNR) thresholds of 2.0 and 1.0 respectively were used as the criteria for Lg data selection. Then, the amplitudes of the Lg data set were then obtained after deleting the pre-event noise. The two-station Lg amplitude ratios were calculated for the roughly aligned triples of event and station-pair. Lg spectral data, including the single-station amplitudes and two-station amplitude ratios, and the resulted QLg model were provided in this Data Repository. |
| Contributor | Lian-Feng Zhao, Xiao-Bi Xie, Zhen-Xing Yao |
| Date | January 2000 - November 2018 |
| Type | The Lg amplitudes were sampled at 58 frequencies distributed log-evenly between 0.05 and 10.0 Hz, and therefore the spectral Lg amplitude data were provided in 58 separated files, with each file corresponding to one frequency indicated by the double-digit number in the name of the file; the resulted QLg model includes QLg distributions at 58 discrete frequencies, correspondingly. |
| Format | All Lg amplitude data, including single-station amplitudes and two-station amplitude ratios, were stored in the ASCII sott.*.b.dat files. The correspondence between the frequency and the double-digit number can be looked up in the file ‘frequency.txt’. The sott.*.b.dat files consist of header lines and data lines. Natural number and zero value occupy the 4th and 5th columns, respectively, which indicates that the current line is the header line for single-station data, where natural number is the sequence number of the recorded event, with the first two columns being the longitude and latitude of the recorded event, 3rd column being the number of lines of the following station data. The header lines for single-station data are immediately followed by data lines, 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 earthquake magnitude. In contrast, zero and natural number occupy the 4th and 5th columns, respectively, which indicates that the current line is the header line for two-station data, where natural number is the sequence number of the recording station, with the first two columns being the longitude and latitude of the station location, 3rd column being the number of lines of the following two-station data. The header lines for two-station data are immediately followed by data 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 earthquake magnitude. The resulted QLg model was stored in the Dataset_LgQmodel.txt file. The Dataset_LgQmodel.txt file consists of a header line for column description, i.e., the first column is frequency; the second and third columns are the longitude and latitude of the spatial discrete points, and the fourth column is QLg value. |
| URL | http://www.geophys.ac.cn/ArticleData/20220719LgamplitudeandQmodel.zip |
| DOI | 10.12197/2022GA022 |
| Source | |
| Language | eng |
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| Coverage | |
| Rights | The China National Digital Seismic Network (CNDSN) and the Incorporated Research Institutions for Seismology (IRIS) |