A catalogue of non-tectonic earthquakes in central-eastern Italy

Marco Cattaneo Marco Cattaneo,Chiara Ladina Chiara Ladina,Enrico Caffagni Enrico Caffagni,Ezio D'alema Ezio D'Alema,Massimo Frapiccini Massimo Frapiccini,Giancarlo Monachesi Giancarlo Monachesi,Simone Marzorati Simone Marzorati,Simona Carannante Simona Carannante

doi:10.4401/ag-6434

Marco Cattaneo Marco Cattaneo, Chiara Ladina Chiara Ladina + Show 6 more

Open Access

https://doi.org/10.4401/ag-6434

Copy DOI

Abstract

<p>Quarry explosions and other non-tectonic signals can contaminate seismic catalogues, especially in areas where dense seismic networks allow to detect even low energy events. This paper presents the algorithm adopted for the discrimination of non-tectonic earthquakes in central-eastern Italy, an area with a high rate of events of this kind (4500 were recorded in the 1996-2012 period). Starting from an empirical classification based on the analysis of areas in which the ratio between daytime and nighttime events is strongly anomalous, a waveform similarity approach allows to simplify the procedure of detection making the final classification more robust. The resulting catalogue of non-tectonic earthquakes (quarry blasts and other anomalous signals) is a useful tool for anyone wanting to carry out a careful analysis of the tectonic seismicity of central-eastern Italy.</p>

Highlights

It is well known that seismic networks allow to record signals generated by natural earthquakes, and by artificial sources
As quarry blasts usually are low energy events, obviously it is more frequent to record them in areas where the detection threshold of a seismic network is lower
For example Allmann et al [2008] found that quarry blasts in southern California exhibit anomalously high spectral fall-off rates compared to earthquakes of the same estimated moment magnitude, but this discriminant is not able to completely separate the two populations of events

Summary

Introduction

It is well known that seismic networks allow to record signals generated by natural earthquakes, and by artificial sources. As quarry blasts usually are low energy events, obviously it is more frequent to record them in areas where the detection threshold of a seismic network is lower The inclusion of these events in earthquake catalogues can contaminate our view of the true natural process under investigation, in term of both space and time distribution. The catalogue includes quarry blasts, and other events whose waveforms suggest a non-tectonic source; these data can be used as a reference for the extraction of catalogues of natural seismicity. The available data This work is based on the routine analysis of local seismicity performed by the staff of the Rete Sismica Marchigiana (Marchesan Seismic Network; RSM) This network was managed by the OGSM up to 2002, when the Marche Region administration took direct control of earthquake monitoring on a regional scale, starting at the same time a close cooperation with INGV that led to a progressive integration of the regional seismic network within the national network, completed in 2009.

A CATALOGUE OF NON-TECTONIC EARTHQUAKES IN CENTRAL-EASTERN ITALY

Data and sharing resources