Energy envelope data for seismic attenuation study of the Gargano Promontory (Southern Italy) and surrounding regions
Description
The dataset includes the seismic energy envelopes used to study the coda attenuation Qc quality factor in the Gargano Promontory (Southern Italy) and surrounding regions (Filippucci et al., 2019; 2021). The seismic energy envelopes are band pass filtered (Butterworth, two-poles) in frequency bands with central frequency fc= 2, 3, 4, 5, 6, 8, 10, 12, 14 and 16 Hz, with a bandwidth ranging inside the interval [fc/√2; fc*√2]. Seismic envelopes are already cut in the time window of the descending energy, ready to be fitted in order to compute the seismic energy attenuation of the sampled medium. In order to reproduce the results of the Qc study (Filippucci et al., 2019; 2021) a single scattering model (Aki, 1969) should be used. - For earthquakes occurred from June to September 2013 the folder is Seismic_Envelopes_2013.zip. In this compressed folder, the seismic event folders are collected named with a numerical code indicating year, month, day, hour, minute of the event origin time (format AAAAMMDDHHmm). In each event folder, the seismic envelope files in *.dat format. - For earthquakes occurred from July 2015 to August 2018 the folder is Seismic_Envelopes_2015_2018.zip. In this compressed folder, the seismic event folders are collected named with a numerical code indicating year, month, day, hour, minute of the event origin time (format AAAAMMDDHHmm). In each event folder, the seismic envelope files in *.TXT format. The original seismograms together with the event's location and magnitude, station locations and velocity model have been already published (https://data.mendeley.com/datasets/7b5mmdjpt3/5).
Files
Steps to reproduce
Starting from the seismograms (Mendeley Data, V5, doi: 10.17632/7b5mmdjpt3.5), each recording was processed as following: 1) filtering of each track in 10 different bands with central frequencies fc = 2, 3, 4, 5, 6, 8, 10, 12, 14, 16 Hz, with a bandwidth ranging inside the interval [fc/√2; fc*√2] 2) Subsequently, each filtered recording was converted into the envelope, i.e. a transform expressed by the following equation: Env = √ [H (t)^2 + S (t)^2] where where H is the Hilbert transform of the signal S (t). 3) Each obtained envelope was cut after the S-wave arrival time upon the arrival of any bump or irregularity in the signal or until it disappears in the noise level. This is a manual and time-expensive procedure. 4) Signal are ready to be inverted by using an appropriate model.