Discrimination of quarry blasts from tectonic microearthquakes in the Hyblean Plateau (Southeastern Sicily)
Main Article Content
Abstract
The seismic network set up in the Hyblean Plateau (Southeastern Sicily) in the framework of the POSEIDON project is aimed at the seismic surveillance of the zone, and in particular the identification of faults with enhanced activity. The seismic activity as inferred from the records of the years 1994-1998 showed an apparent concentration of events in the zone between Augusta and Syracuse where important petrochemical facilities are present, with a resulting elevated secondary seismic risk. However, the heterogeneity in the distribution of events with respect to the time of day made us suspect that these seismicity maps are severely biased by artificial events, such as quarry explosions. We distinguished between tectonic earthquakes and quarry blasts by the inspection of waveforms of certain key stations, and by spectral analysis. As a general rule we found that the local tectonic microearthquakes are richer in high frequencies than the quarry blasts. All events which were identified as quarry blasts occurred during the daytime between 08:00 a.m. and 03:00 p.m. GMT and on weekdays from Monday to Friday. The aforementioned concentration of seismicity between Augusta and Syracuse disappeared when filtering out these events. Automatic discrimination was carried out in a straightforward way using Artificial Neural Networks (ANN) in a supervised classification. The application of the ANN to various test data sets gave a success of about 95%. This showed that our results obtained with a visual discrimination are mathematically reproducible and not arbitrary.
Article Details
How to Cite
Ursino, A., Langer, H., Scarfì, L., Di Grazia, G. and Gresta, S. (2001) “Discrimination of quarry blasts from tectonic microearthquakes in the Hyblean Plateau (Southeastern Sicily)”, Annals of Geophysics, 44(4). doi: 10.4401/ag-3569.
Issue
Section
OLD
Open-Access License
No Permission Required
Istituto Nazionale di Geofisica e Vulcanologia applies the Creative Commons Attribution License (CCAL) to all works we publish.
Under the CCAL, authors retain ownership of the copyright for their article, but authors allow anyone to download, reuse, reprint, modify, distribute, so long as the original authors and source are cited. No permission is required from the authors or the publishers.
In most cases, appropriate attribution can be provided by simply citing the original article.
If the item you plan to reuse is not part of a published article (e.g., a featured issue image), then please indicate the originator of the work, and the volume, issue, and date of the journal in which the item appeared. For any reuse or redistribution of a work, you must also make clear the license terms under which the work was published.
This broad license was developed to facilitate open access to, and free use of, original works of all types. Applying this standard license to your own work will ensure your right to make your work freely and openly available. For queries about the license, please contact ann.geophys@ingv.it.