scholarly journals Technologies and new approaches used by the INGV EMERGEO Working Group for real-time data sourcing and processing during the Emilia Romagna (northern Italy) 2012 earthquake sequence

2012 ◽  
Vol 55 (4) ◽  
Author(s):  
Giuliana Alessio ◽  
Laura Alfonsi ◽  
Carlo Alberto Brunori ◽  
Pierfrancesco Burrato ◽  
Giuseppe Casula ◽  
...  
Keyword(s):  
Seismic Event ◽  
Main Shock ◽  
Northern Italy ◽  
Earthquake Activity ◽  
Seismic Sequence ◽  
Time Data ◽  
Broad Area ◽  
Epicentral Area ◽  
Po Plain ◽  
Real Time Data

<p>On May 20, 2012, a Ml 5.9 seismic event hit the Emilia Po Plain, triggering intense earthquake activity along a broad area of the Po Plain across the provinces of Modena, Ferrara, Rovigo and Mantova (Figure 1). Nine days later, on May 29, 2012, a Ml 5.8 event occurred roughly 10 km to the SW of the first main shock. These events caused widespread damage and resulted in 26 victims. The aftershock area extended over more than 50 km and was elongated in the WNW-ESE direction, and it included five major aftershocks with 5.1 ≤Ml ≤5.3, and more than 2000 minor events (Figure 1). In general, the seismic sequence was confined to the upper 10 km of the crust. Minor seismicity with depths ranging from 10 km to 30 km extended towards the southern sector of the epicentral area (ISIDe, http://iside.rm.ingv.it/). […]</p><br />

scholarly journals Searching for the effects of the May-June 2012 Emilia seismic sequence (northern Italy): medium-depth deformation structures at the periphery of the epicentral area

2012 ◽  
Vol 55 (4) ◽  
Author(s):  
Lisa Borgatti ◽  
Antonio Edoardo Bracci ◽  
Stefano Cremonini ◽  
Giovanni Martinelli
Keyword(s):  
Ground Level ◽  
Northern Italy ◽  
Seismic Sequence ◽  
Surface Phenomena ◽  
Po River ◽  
Epicentral Area ◽  
Ground Fissures ◽  
Groundwater Levels ◽  
Geological Surveys ◽  
Emilia Romagna Region

<p>In 2012, a seismic sequence occurred in the lowlands of the Emilia-Romagna Region (northern Italy), between the borders of the Modena, Ferrara and Bologna Provinces. It consisted of seven mainshocks (5.9 &gt; Ml &gt; 5) that were recorded between May 20 and 29, 2012 [INGV 2012a] and 2,200 minor earthquakes [INGV 2012b]. An interferometric analysis [Bignami et al. 2012, Salvi et al. 2012, this volume] highlighted three main deformation areas, each of which was 12 km wide (from S to N) and 10 km to 20 km long in an ESE-WNW to E-W direction, thus affecting an area of about 600 km2 (Figure 1). Field and aerial geological surveys recorded numerous surficial effects, such as: (i) sediment liquefaction [Crespellani et al. 2012]; (ii) localized ground fissures resembling surficial faulting [Fioravante and Giretti 2012] (Figure 2); (iii) groundwater levels rising up to 400 cm above the local ground level in phreatic wells during the mainshocks (lower values were observed in confined aquifers); and (iv) dormancy of previously known sinkholes [Borgatti et al. 2010, Cremonini 2010a, and references therein]. Some of the observed surface phenomena were previously recorded as coseismic effects during the earthquakes of Ferrara (1570) and Argenta (1624) [Boschi et al. 1995, Galli 2000], together with the early rising of the water level of the Po River in the Stellata section. […]</p>

Seismic Performance of Industrial Sheds and Liquefaction Effects During May 2012 Emilia Earthquakes Sequence in Northern Italy

2014 ◽  
Vol 08 (02) ◽  
pp. 1450009 ◽  
Author(s):  
Gian Paolo Cimellaro ◽  
Marco Chiriatti ◽  
Hwasung Roh ◽  
Andrei M. Reinhorn
Keyword(s):  
Emergency Response ◽  
Working Hours ◽  
Northern Italy ◽  
Seismic Sequence ◽  
Epicentral Area ◽  
Existing Structures ◽  
Industrial Sites ◽  
Emilia Earthquake ◽  
Private Homes ◽  
Seismic Area

On May 20, 2012 at 2:03 UTC, a Mw 6.1 earthquake occurred in Emilia Region of Northern Italy. The event was preceded by a Ml 4.1 foreshock on May 19, 2012 at 23:13 UTC, and followed by several aftershocks, twenty of them with a magnitude Mw greater than 4. The epicentral area of the seismic sequence covers alluvial lowland that is occupied by both agricultural and urbanized areas. Liquefaction effects were observed in several villages on the west side of Ferrara which were built upon former river beds such as the Reno River. The Emilia seismic sequence resulted in 27 casualties, several of whom were among the workers in the factories that collapsed during working hours, and there was extensive damage to monuments, public buildings, industrial sites and private homes. Almost no municipalities hit by 2012 earthquake were classified as seismic area before 2003; therefore, most of the existing structures had been designed without taking in account the seismic actions. The main aims of MCEER field mission was to document the emergency response and the most common damage mechanisms of industrial sheds during Emilia earthquake sequence which are shown and discussed in detail.

scholarly journals GPS observations of coseismic deformation following the May 20 and 29, 2012, Emilia seismic events (northern Italy): data, analysis and preliminary models

2012 ◽  
Vol 55 (4) ◽  
Author(s):  
Enrico Serpelloni ◽  
Letizia Anderlini ◽  
Antonio Avallone ◽  
Valentina Cannelli ◽  
Adriano Cavaliere ◽  
...  
Keyword(s):  
Sedimentary Cover ◽  
Active Faults ◽  
Northern Italy ◽  
Coseismic Deformation ◽  
Seismic Sequence ◽  
Stress Indicators ◽  
Po Plain ◽  
Fold And Thrust Belt ◽  
The City ◽  
Gps Observations

<p>In May-July 2012, a seismic sequence struck a broad area of the Po Plain Region in northern Italy. The sequence included two Ml &gt;5.5 mainshocks. The first one (Ml 5.9) occurred near the city of Finale Emilia (ca. 30 km west of Ferrara) on May 20 at 02:03:53 (UTC), and the second (Ml 5.8) occurred on May 29 at 7:00:03 (UTC), about 12 km southwest of the May 20 mainshock (Figure 1), near the city of Mirandola. The seismic sequence involved an area that extended in an E-W direction for more than 50 km, and included seven Ml ≥5.0 events and more than 2,300 Ml &gt;1.5 events (http://iside.rm.ingv.it). The focal mechanisms of the main events [Pondrelli et al. 2012, Scognamiglio et al. 2012, this volume] consistently showed compressional kinematics with E-W oriented reverse nodal planes. This sector of the Po Plain is known as a region characterized by slow deformation rates due to the northwards motion of the northern Apennines fold-and-thrust belt, which is buried beneath the sedimentary cover of the Po Plain [Picotti and Pazzaglia 2008, Toscani et al. 2009]. Early global positioning system (GPS) measurements [Serpelloni et al. 2006] and the most recent updates [Devoti et al. 2011, Bennett et al. 2012] recognized that less than 2 mm/yr of SW-NE shortening are accommodated across this sector of the Po Plain, in agreement with other present-day stress indicators [Montone et al. 2012] and known active faults [Basili et al. 2008]. In the present study, we describe the GPS data used to study the coseismic deformation related to the May 20 and 29 mainshocks, and provide preliminary models of the two seismic sources, as inverted from consensus GPS coseismic deformation fields. […]</p>

scholarly journals Macroseismic intensity investigation of the November 2014, M=5.7, Vrancea (Romania) crustal earthquake

2016 ◽  
Vol 59 (5) ◽  
Author(s):  
Angela Petruta Constantin ◽  
Iren Adelina Moldovan ◽  
Andreea Craiu ◽  
Mircea Radulian ◽  
Constantin Ionescu
Keyword(s):  
Seismic Event ◽  
Main Shock ◽  
Focal Depth ◽  
Earthquake Occurrence ◽  
Epicentral Area ◽  
Ground Shaking ◽  
Crustal Earthquake ◽  
Historical Times ◽  
Vrancea Seismogenic Region ◽  
North Latitude

On November 22, 2014 at 21:14:17 local hour (19:14:17 GMT) a  M<sub>L</sub>=5.7 crustal earthquake occurred in the area of Marasesti city of Vrancea county (Romania) - the epicenter was located at north latitude 45.87° and east longitude 27.16°, with a focal depth of 39 km. This earthquake is the main shock of a sequence that started with this and lasted until the end of January. During the sequence, characterized by the absence of foreshocks, a number of 75 earthquakes were recorded in 72 hours, the largest of which occurred in the same day with the main shock, at 22:30 (M<sub>L</sub>= 3.1). The crustal seismicity of Vrancea seismogenic region is characterized by moderate earthquakes with magnitudes that have not exceeded M<sub>W</sub> 5.9, this value being assigned to an earthquake that occurred in historical times on March 1, 1894 (Romplus catalogue). Immediately after the 2014 earthquake occurrence, the National Institute for Earth Physics (NIEP) sent macroseismic questionnaires in all affected areas, in order to define the macroseismic field of ground shaking. According to macroseismic questionnaires survey, the intensity of epicentral area reached VI MSK, and the seismic event was felt in all the extra-Carpathian area. This earthquake caused general panic and minor to moderate damage to the buildings in the epicentral area and the northeast part of country. The main purpose of this paper is to present the macroseismic map of the earthquake based on the MSK-64 intensity scale.

scholarly journals The ShakeMaps of the Amatrice, M6, earthquake

2016 ◽  
Vol 59 ◽  
Author(s):  
Licia Faenza ◽  
Valentino Lauciani ◽  
Alberto Michelini
Keyword(s):  
Ground Motion ◽  
Data Exchange ◽  
Main Shock ◽  
Central Italy ◽  
Strong Motion ◽  
Rupture Directivity ◽  
Time Data ◽  
Epicentral Area ◽  
Ground Shaking ◽  
Motion Data

In this paper we describe the performance of the ShakeMap software package and the fully automatic procedure, based on manually revised location and magnitude, during the main event of the Amatrice sequence with special emphasis to the M6 main shock, that struck central Italy on the 24th August 2016 at 1:36:32 UTC. Our results show that the procedure we developed in the last years, with real-time data exchange among those institutions acquiring strong motion data, allows to provide a faithful description of the ground motion experienced throughout a large region in and around the epicentral  area. The prompt availability of the rupture fault model, within three hours after the earthquake occurrence, provided a better descriptions of the level of strong ground motion throughout the affected area.  Progressive addition of  station data and  manual verification of the data insures improvements in the description of the experienced ground motions.  In particular, comparison between the MCS intensity shakemaps and preliminary field macroseismic reports show favourable similarities.  Finally the overall  spatial pattern of the ground motion of the main shock is consistent with reported rupture directivity toward NW and reduced levels of ground shaking toward SW probably linked to the peculiar source effects of the earthquake.

scholarly journals Brief communication "Ground failure and liquefaction phenomena triggered by the 20 May 2012 Emilia-Romagna (Northern Italy) earthquake: case study of Sant'Agostino–San Carlo–Mirabello zone"

2012 ◽  
Vol 12 (10) ◽  
pp. 3177-3180 ◽  
Author(s):  
R. Caputo ◽  
G. Papathanassiou
Keyword(s):  
Main Shock ◽  
Ground Deformation ◽  
Lateral Spreading ◽  
Northern Italy ◽  
Field Observations ◽  
Secondary Effects ◽  
Large Area ◽  
Po Plain ◽  
Ground Failure

Abstract. The basic aim of this study was to observe and report the earthquake-induced ground deformation of the MW = 6.1 Emilia-Romagna (Northern Italy) event that occurred on the 20 May 2012. The event caused widespread structural damages in a large area of the Po Plain, while the most characteristic geological effects were ground failure, lateral spreading and liquefaction. This post-earthquake reconnaissance report focuses on secondary effects within the area between the villages of Sant'Agostino, San Carlo and Mirabello located along a former reach of the Reno River. Our field observations started just few hours after the main shock until the 28 May 2012.

Operational Aftershock Forecasting for Mw7.3 Sarpol-e Zahab (2017) Earthquake in Western Iran

2020 ◽  
Author(s):  
Hossein Ebrahimian ◽  
Fatemeh Jalayer ◽  
Hamid Zafarani
Keyword(s):  
Seismic Event ◽  
Border Region ◽  
Earthquake Forecasting ◽  
Model Parameters ◽  
Time Interval ◽  
Seismic Sequence ◽  
Epicentral Area ◽  
Western Iran ◽  
Spatio Temporal ◽  
Robust Reliability

&lt;p&gt;&lt;strong&gt;Methodology:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;The implementation of short-term forecasts for emergency response management in the immediate aftermath of a seismic event, and in the presence of an ongoing seismic sequence, requires two basic components: scientific advisories expressed in terms of risk assessment, and protocols that establish how the scientific results can be translated into decisions/actions for risk mitigation. The operational earthquake forecasting framework is geared towards providing scientific advisories in the form of time-dependent probabilities expressing seismicity, hazard and risk that can be practically translated into decisions. Considering the triggered sequence of aftershocks in the process of post-event decision-making and prioritization of emergency operations still seems to need and to deserve much more attention. To this end, the adopted novel and fully-probabilistic procedure succeeds in providing spatio-temporal predictions of aftershock occurrence in a prescribed forecasting time interval (in the order of hours or days). The procedure aims at exploiting the information provided by the ongoing seismic sequence in quasi-real time considering the time needed for registering and transmitting the data. The versatility of the Bayesian inference is exploited to adaptively update the forecasts based on the incoming information as it becomes available. The aftershock clustering in space and time is modelled based on an Epidemic Type Aftershock Sequence (ETAS). One of the main novelties of the proposed procedure is that it considers the uncertainties in the aftershock occurrence model and its model parameters. This is done by moving within a framework of robust reliability assessment which enables the treatment of uncertainties in an integrated manner. Pairing up the Bayesian robust reliability framework and the suitable simulation schemes (Markov Chain Monte Carlo Simulation) provides the possibility of performing the whole forecasting procedure with minimum (or no) need of human interference.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Application:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;This procedure is demonstrated through a retrospective application to early forecasting of seismicity associated with the 2017 Sarpol-e Zahab seismic sequence activities. On Sunday November 12, 2017, at 18:18:16 UTC, (21:48:16 local time), a strong earthquake with Mw7.3 occurred in western Iran in the border region between Iran and Iraq in vicinity of the Sarpol-e Zahab town. Unfortunately, this catastrophic seismic event caused 572 causalities, thousands of injured and vast amounts of damage to the buildings, houses and infrastructures in the epicentral area. The mainshock of this seismic sequence was felt in the entire western and central provinces of Iran and surrounding areas. The main event was preceded by a foreshock with magnitude 4.5 about 43 minutes before the mainshock that warned the local residence to leave their home and possibly reduced the number of human casualties. More than 2500 aftershocks with magnitude greater than 2.5 have been reported up to January 2019 with the largest registered aftershock of Mw6.4. The fully simulation-based procedure is examined for both Bayesian model updating of ETAS spatio-temporal model and robust operational forecasting of the number of events of interest expected to happen in various time intervals after main events within the sequence. The seismicity is predicted within a confidence interval from the mean estimate.&lt;/p&gt;

scholarly journals Seismicity anomalies prior to the 13 December 2008, <i>M<sub>s</sub></i>=5.7 earthquake in Central Greece

2009 ◽  
Vol 9 (2) ◽  
pp. 501-506 ◽  
Author(s):  
G. Chouliaras
Keyword(s):  
Physical Meaning ◽  
Seismic Activity ◽  
Main Shock ◽  
Seismic Quiescence ◽  
Time To Failure ◽  
Seismic Sequence ◽  
Occurrence Time ◽  
Epicentral Area ◽  
Central Greece ◽  
Shock Modeling

Abstract. This investigation has applied a recent methodology to identify seismic quiescence and seismic acceleration, prior to the occurrence of the 13 December 2008, Ms=5.7 earthquake in Central Greece. Anomalous seismic quiescence is observed around the epicentral area almost twelve years prior to the main shock and it lasted for a period of about four and a half years. After this period an acceleration in seismic activity began and lasted until the main shock. Modeling this seismic sequence with the time-to-failure equation and with a fixed value of the exponent "m" equal to 0.32, shows a successful estimation of the occurrence time of the main event within a few days. The physical meaning of this particular choice of the "m" value is discussed.

scholarly journals Source complexity of the May 20, 2012, Mw 5.9, Ferrara (Italy) event

2012 ◽  
Vol 55 (4) ◽  
Author(s):  
Davide Piccinini ◽  
Nicola Alessandro Pino ◽  
Gilberto Saccorotti
Keyword(s):  
Main Shock ◽  
Thrust Fault ◽  
Point Of View ◽  
Historical Event ◽  
Seismic Sequence ◽  
Severe Damage ◽  
Populated Area ◽  
Po Plain ◽  
The City ◽  
The Town

A Mw 3.9 foreshock on May 19, 2012, at 23:13 UTC, was followed at 02:03 on May 20, 2012, by a Mw 5.9 earthquake that hit a densely populated area in the Po Plain, west of the city of Ferrara, Italy (Figure 1). Over the subsequent 13 days, six Mw &gt;5 events occurred; of these, the most energetic was a Mw 5.8 earthquake on May 29, 2012, 12 km WSW of the main shock. The tragic balance of this sequence was 17 casualties, hundreds of injured, and severe damage to the historical and cultural heritage of the area. From a seismological point of view, the 2012 earthquake was not an outstanding event in its regional context. The same area was hit in 1996 by a Mw 5.4 earthquake [Selvaggi et al. 2001], and previously in 1986 and in 1967 (DBMI11) [Locati et al. 2011]. The most destructive historical event was the 1570, Imax 8 event, which struck the town of Ferrara [Guidoboni et al. 2007, Rovida et al. 2011]. The 2012 seismic sequence lasted for several weeks and probably developed on a well-known buried thrust fault [Basili et al. 2008, Toscani et al. 2009, DISS Working Group 2010], at depths between 2 km and 10-12 km. […]

Spatial-temporal variation of seismicity and spectrum of the 1980 earthquake swarm near the Izu Peninsula, Japan

1984 ◽  
Vol 74 (1) ◽  
pp. 199-221
Author(s):  
Mizuho Ishida
Keyword(s):  
Temporal Variation ◽  
Main Shock ◽  
Earthquake Swarm ◽  
Maximum Pressure ◽  
Earthquake Activity ◽  
The South ◽  
Epicentral Area ◽  
Izu Peninsula ◽  
Wave Forms ◽  
Swarm Activity

Abstract The spatial-temporal variation of seismicity of the 1980 earthquake swarm off the east coast of the Izu Peninsula, Japan, was investigated. Hypocentral distribution, focal mechanism, wave forms, and spectra of seismic waves were studied. The hypocenters were relocated by using the master event method. The forerunning earthquakes which started about one week before the largest shock (main shock), the 1980 Izu-Hanto-Toho-Oki earthquake (M = 6.7), occurred within the quiescent area of the earthquake activity for the preceding one year. The swarm area migrated toward the south with time and triggered the main shock in June 1980. The fault dimension and geometry were estimated from the aftershock area: the fault length and width are 14 km and 8 km; the strike and dip angles of the fault are N15°W and 65° to N75°E. Locations of the events in an earlier earthquake swarm (1978) were also examined by using difference in the S-P time at five selected stations distributed around the epicentral area. The 1978 swarm events were found to have clustered within a very small area of 8 ×1 km2 located about 2 km to the west of the 1980 swarm area. The earthquakes which occurred after the main shock of the 1980 swarm were classified into two groups, aftershocks and swarm events, according to the location of epicenters, wave forms, and spectra of S waves. The peak frequencies of spectra were distributed around 5 to 8 Hz for the aftershocks and around 10 to 15 Hz for the swarm events. Most of the aftershocks, characterized by low-frequency content, occurred to the south of the main shock within 2 weeks after the main shock. The number of aftershocks decayed following the modified Omori's formula with p = 1.5 ± 0.3. The swarm activity, on the other hand, continued intermittently for about 1 month after the main shock. The 1980 seismic activity is interpreted as a complex of a foreshock-main shock-aftershock sequence and swarm activity. The direction of the longer axis of the swarm area coincided with the direction of the maximum pressure axis of the main shock. The trend of the aftershock zone coincided with the strike of the fault planes of the main shock and aftershocks. This feature strongly suggests that tension cracks trending in the maximum stress direction opened prior to the occurrence of the main shock. The opening of cracks may be accounted for by increasing of interstitial pore pressure associated with increase in regional stress.

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