The April 6, 2009, Mw 6.3, L'Aquila sequence: weak-motion and strong-motion data recorded by the RAIS temporary stations

Marco Massa Marco Massa,Simone Marzorati Simone Marzorati,Gianlorenzo Franceschina Gianlorenzo Franceschina,Ezio D'alema Ezio D'Alema,Paolo Augliera Paolo Augliera

doi:10.4401/ag-4565

Marco Massa Marco Massa, Simone Marzorati Simone Marzorati + Show 3 more

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https://doi.org/10.4401/ag-4565

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Abstract

The aim of this study is the sharing of waveforms recorded by several Istituto Nazionale di Geofisica e Vulcanologia (INGV) temporary stations (managed by the Milan-Pavia section; INGV MI-PV). These stations were installed after the April 6, 2009, Mw 6.3, L'Aquila earthquake (central Italy). The work synthesizes the activities conducted in the field by the INGV MI-PV working group over the three months following the mainshock. The field activities were developed in four different phases that were defined according to their time periods. Starting from April 7, 2009, for the first phase, the temporary stations were installed in correspondence with the more damaged areas. The scope was to record the strongest aftershocks in the days that followed the mainshock. In this phase, the stations were composed of a six-component acquisition system that was coupled with both a weak-motion and a strong-motion sensor. After the first month, the last three phases of installation investigated the seismic responses of sites located in the epicentral area, involving villages within a radius of about 20 km from the epicenter of the April 6 mainshock. In this way, over four specific time-period phases, the stations were installed in sites with different lithological and geomorphological conditions. The instruments worked from April 7 to July 14, 2009; in this period, 9,155 aftershocks (134,262 accelerometric waveforms and 133,242 velocimetric waveforms), with ML ≤5.3 were recorded. This study describes the dataset of these earthquake waveforms recorded with both velocity and acceleration transducers. Selected waveforms are available through ftp://ftp.mi.ingv.it/download/RAIS-TS_rel01/, with their corresponding information concerning instrumental characteristics, installation sites, and earthquakes recorded.

Highlights

On April 6, 2009, a Mw 6.3 normal faulting event struck close to the city of L'Aquila in the Abruzzo region, central Italy [Ameri et al 2009, Anzidei et al 2009, Cirella et al 2009]
In the first month after the April 6, 2009, Mw 6.3, L'Aquila mainshock, the Rete Accelerometrica in Italia Settentrionale (RAIS)-TS were mainly installed corresponding to villages that had experienced the greatest damage
The present study describes the features of the data collected by RAIS-TS in the epicentral area of the L'Aquila mainshock (Mw 6.3) during these four phases over the three months following the April 6, 2009, mainshock

Summary

Introduction

On April 6, 2009, a Mw 6.3 normal faulting event struck close to the city of L'Aquila in the Abruzzo region, central Italy [Ameri et al 2009, Anzidei et al 2009, Cirella et al 2009]. The INGV Milan-Pavia section (INGV MI-PV) made available the mobile stations of the Rete Accelerometrica in Italia Settentrionale (RAIS; the strong-motion network of northern Italy, http://rais.mi.ingv.it) [Augliera et al 2009], to set up a highdensity temporary network of stations (the RAIS-TS). In this way, INGV MI-PV operated together with the INGV Rome section (http://www.roma1.ingv.it/) and the Helmholtz Centre, Potsdam, Germany (http://www.gfzpotsdam.de/portal/gfz/home) in the framework of a coordinated experiment [Cultrera et al 2009]. The RAIS-TS were installed with the aim of recording the more energetic aftershocks and to evaluate the presence of possibile nonlinear effects; in particular, accelerometric sensors were used to avoid signal saturation

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