Publication Date:
2017-04-04
Description:
On May 20, 2012, at 02:03 UTC, a moderate earthquake
of local magnitude, ML 5.9 started a seismic sequence in the
central Po Plain of northern Italy (Figure 1) [Scognamiglio
et al. 2012, this volume]. The mainshock occurred in an area
where seismicity of comparable magnitude has neither been
recorded nor reported in the historical record over the last
1,000 years [Rovida et al. 2011].
The aftershock sequence evolved rapidly near the epicenter,
with diminishing magnitudes until May 29, 2012,
when at 07:00 UTC a large earthquake of ML 5.8 occurred
12 km WSW of the mainshock, starting a new seismic sequence
in the western area (Figure 1); a total of seven earthquakes
with ML 〉5 occurred in the area between May 20 and
June 3, 2012 (Figure 1). The details of the seismic sequence
can be found in the report by Scognamiglio et al. [2012].
Immediately after the mainshock, the Italian Department
of Civil Protection (Dipartimento di Protezione
Civile; DPC) requested the Italian Space Agency (Agenzia
Spaziale Italiana; ASI) to activate the Constellation of Small
Satellites for Mediterranean Basin Observation (COSMOSkyMed)
to provide Interferometric Synthetic Aperture
Radar (InSAR) coverage of the area. COSMO-SkyMed consists
of four satellites in a 16-day repeat-pass cycle, with
each carrying the same SAR payload [Italian Space Agency
2007]. In the current orbital configuration, within each 16-
day cycle, image pairs with temporal baselines of 1, 3, 4 and
8 days can be formed from the images acquired by the four
different sensors. Combined with the availability of a wide
range of electronically steered antenna beams with incidence
angles ranging from about 16° to 50° at near-range
[E-geos 2012], this capability allows trade-offs between temporal
and spatial coverage to be exploited during acquisition
planning.
A joint team involving the Istituto Nazionale di Geofisica
e Vulcanologia (INGV; National Institute of Geophysics
and Volcanology) and the Istituto per il Rilevamento
Elettromagnetico dell'Ambiente (IREA-CNR; Institute for
the Electromagnetic Sensing of the Environment) was activated
to generate InSAR-based scientific products to support
the emergency management. In this framework, the
ASI and DPC requested that INGV activated the Spacebased
Monitoring System for Seismic Risk Management
(SIGRIS) [Salvi et al. 2010]. SIGRIS consists of a hardware/
software infrastructure that is designed to provide the
DPC with value-added information products in the different
phases of the seismic cycle. During earthquake emergencies,
its goal is to rapidly provide decision-support
products, such as validated ground-displacement maps and
seismic source models.
This study reports the details of the activation of the
SIGRIS system in the case of the Emilia sequence. It provides
a description of the COSMO-SkyMed datasets and processing
procedures, as well as selected interferometric results for
the coseismic and post-seismic ground deformation. Fault
modeling results for the seismic sources of the largest earthquakes,
and a more detailed discussion of the observed
ground deformations are reported in Pezzo et al. [2012].
Description:
Published
Description:
797-802
Description:
5T. Sorveglianza sismica e operatività post-terremoto
Description:
JCR Journal
Description:
open
Keywords:
SAR interferometry,
;
Co-seismic displacement
;
Earthquakes
;
SIGRIS system
;
Italy.
;
04. Solid Earth::04.03. Geodesy::04.03.07. Satellite geodesy
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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