Site, Attenuation and Source Parameters for the East Anatolian Fault Zone (Türkiye) Derived from Spectral Decomposition

This dataset presents the results of a spectral decomposition analysis performed using the GITPy (Morasca et al., 2025) in the East Anatolian Fault Zone (EAFZ), Türkiye to isolate the contributions of sites, attenuation and site effects using the FAS available in the Zenodo repository (Colavitti et al., 2024, https://doi.org/10.5281/zenodo.15910095) and described in the related paper (Colavitti et al., 2025, https://doi.org/10.5194/essd-2024-448). This study focuses on source parameters for 9,176 earthquakes and their spatio-temporal variability within the rupture area of the 6 February, 2023 Kahramanmaras earthquake sequence. The product consists of a compressed folder GIT_EAFZ.zip, containing three subfolders: SITES, ATTENUATION and SOURCES, whose contents are described below. SITES/ Each *txt file, named as Net_Code.Sta_Code..TypeSensor_Component.txt, contains a header (first line) where the fields are: Net_Code.Sta_Code, where Net_Code is the network code and Sta_Code is the station code; Type of Sensor, is the used seismic sensor; Component, here the component is always H (Horizontal); Lat is the Latitude [°] of the station; Lon is the Longitude [°] of the station; Elevation is the altitude [m] of the station; Site Flag, Logic flag if the site is a reference site (True) or not a reference site (False). The other lines in the file are divided into two columns: Frequency [Hz], from 0.53 to 25.06 Hz; Site response is the site response for a single station. Note that there may be NaN values. Notes: - Reference stations are: KO.BNGB, KO.BNN, KO.DARE, KO.KARA, KO.SENK, KO.TOKT, TU.AKSY, TU.YAYL and TU.YURE. - We assumed a reference amplification model with a site-specific component of high-frequency attenuation parameter k0 of 0.035 s, consistent with the work of Bindi et al. (2023) for the EAFZ. ATTENUATION/ The file consists of a 24 x 69 matrix. The first element of each row is the hypocentral distance, with the following values [in km], from the first to the twenty-fourth row: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, and 120. From the second to the sixty-ninth element of each row, the attenuation values are reported, corresponding to frequencies ranging from 0.53 Hz to 25.06 Hz. SOURCES/ Each file is named with the event ID in the format YYMMDDhhmmss. The header (first line) of each file contains the following fields: ID Event, in the format YYMMDDhhmmss, where YY is the year, MM is the month, DD is the day, hh is the hour, mm is the minute and ss is the second of the event in UTC time; Ml, Local Magnitude; Lat is the Latitude [°] of the event; Lon is the Longitude [°] of the event; Depth [km] is the earthquake depth. The other lines in the file are divided into two columns: Frequency [Hz], from 0.53 to 25.06 Hz; Source response [cm/s], is the response of the source of a single earthquake. Note that there may be NaN values. The file Source_Params_GIT_EAFZ.csv contains a table with the following fields: Ev_ID, the ID of the event in the format YYMMDDhhmmss, where YY is the year, MM is the month, DD is the day, hh is the hour, mm is the minute and ss is the second of the event in UTC time Ev_Lat is the Latitude [°] of the event; Ev_Lon is the Longitude [°] of the event; Ev_Depth is the depth [km] of the event; Ml is the local magnitude of the event; Mw is the moment magnitude of the event; Spatial_Clust is a spatial flag to which the event may belong: "NONE": no cluster; "CLUST #1": Nurdağı; "CLUST #2": Sürgü; "CLUST #1, CLUST #2": belonging to both clusters. For details on cluster procedure, see Melgar et al. (2023) and Zaliapin and Ben-Zion (2016); Temp_Clust is a flag indicating the temporal cluster of the event. "FORE" for events occurring before the first shock of the 6 February 2023, "AFTER" for those occurring after; M0 is the seismic moment of the event [N m]; M0_err is the standard error on seismic moment [N m]; fc is the corner frequency [Hz]; fc_error is the standard error on corner frequency [Hz]; Kappa, Source kappa [s]; Kappa_err is the standard error of the source kappa [s]; Stress_drop is the Stress drop [MPa]; Stress_drop_err is the error propagation in Stress drop [MPa]; log10_Er_tot is the log10 of total energy [J]: Er_oss and extrapolated for low and high frequency (Ide and Beroza, 2001). Note: for the source fitting, we anchored the results to a Mw 5.2 event that occurred at 09:19:51 on March, 23 2023, which is also used in the study of Bindi et al. (2023) and represents the maximum magnitude range in our catalog. For full details on the dataset and its scientific context, please refer to the manuscript: L. Colavitti, D. Bindi, G. Tarchini, D. Scafidi, M. Picozzi, and D. Spallarossa (2026). "Unraveling stress and energy variations through spectral analysis of seismic sources in the East Anatolian Fault Zone (Türkiye)", submitted to Bulletin of Seismological Society of America. References Bindi, D., R. Zaccarelli, F. Cotton, G. Weatherill, and S. R. Kotha, 2023. Source Scaling and Ground Motion Variability along the East Anatolian Fault, Seism. Rec., 34, 311-321, https://doi.org/10.1785/0320230034. Brune, J. N., 1970. Tectonic stress and the spectra of seismic shear waves from earthquakes, J. Geophys. Res., 75 (26), https://doi.org/10.1029/JB075i026p04997. Colavitti, L., D. Bindi, G. Tarchini, D. Scafidi, M. Picozzi, and D. Spallarossa, 2024. Data Set of selected strong motion parameters and Fourier Amplitude Spectra for the East Anatolian Fault Zone, Türkiye (January 2019 - February 2024) [Data set], Zenodo, https://doi.org/10.5281/zenodo.15910095. Colavitti , L., D. Bindi, G. Tarchini, D. Scafidi, M. Picozzi, and D. Spallarossa, 2025. 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