may 20 2012 earthquake property damage
(2011) and those obtained in this study. Leninakan, Armenia. The spatial distribution of the aftershocks and the available focal mechanisms indicate WSW-dipping low-angle thrust fault sources with the seismogenic zone located at depths between 5 and 10âkm (locations taken from INGV, http://iside.rm.ingv.it/; Malagnini et al.2012; Scognamiglio et al.2012). Our estimates of total Q also indicate that the frequency dependence of the quality factor weakens at high frequencies from about 5âHz. We discarded the possibility of that event having bigger magnitude because the peak accelerations recorded by the same stations are very similar. The Ï2 model (Aki 1967; Brune 1970) gives stress drop estimates of 2.9 and 1.8âMPa for the main events of May 20 (Mw 6.1) and May 29 (Mw 5.9), respectively. We benefited from helpful discussions with Roberto Paolucci and Daniele Spallarossa. The comparison indicates that in the whole frequency band (1.5â12.0âHz) analysed by Del Pezzo et al. Gruppo Nacionale di Geofisica, S wave attenuation and site effects in the region of Friuli, Italy, Site response of strong motion stations in the Umbria, Central Italy, region, Body wave attenuation in the region of Garda, Italy, Source modelling of the M5â6 Emilia-Romagna, Italy, earthquakes (2012 May 20â29), Comité Européen de Normalisation, Brussels, Eurocode 8: Design of Structures for Earthquake ResistanceâPart 1: General Rules, Seismic Actions and Rules for Buildings, Depth-dependent intrincic and scattering seismic attenuation in north central Italy, The Emilia Thrust earthquake of 20 May 2012 (Northern Italy: Strong Motion and Geological Observation, Tectono-sedimentary setting of the Po Plain and Adriatic Foreland, The spectral decay parameter Kappa in northeastern Sonora, Mexico, Scattering and attenuation of high-frequency seismic waves: Development of the theory of coda waves, Ground-motion characteristics estimated from spectral ratio between horizontal and vertical components of microtremor, Rupture to the trench: dynamic rupture simulations of the 11 March Tohoku earthquake, Geotechnical aspects of May 20, 2012 M5.9 Emilia earthquake, Italy, EUCENTRE, Report V.1.0, Modeling the Fourier amplitude spectrum of local earthquakes from the Coalinga and Mammoth Lakes areas of California, Active fault-related folding in the epicentral area of the December 25, 1222 (Io = IX MCS) Brescia earthquake (Northern Italy): seismotectonic implications, Overview on the strong-motion data recorded during the MayâJune 2012 Emilia seismic sequence, Studying the Ferrara seismic sequence: velocity structure of the Pianura Padana, reliable moment tensor solutions, source scaling, and quantification of the ground motion, Proceedings of the INGV Workshop on 20 May 2012, Mw 6.1, The 2003 data set of seismic waveforms recorded in Lombardia and Veneto regions (Northern Italy): Site selection and M, Site classification assesment for estimating empirical attenuation relationships for North-Central Italy earthquakes, INGV Strong-Motion Data web-portal: a focus on the Emilia seismic sequence of May-June, 2012, (special issue 2012 Pianura Padano-Emiliana seismic sequence), Objective estimation of source parameters and local, Shear wave attenuation in the lithosphere beneath Italy and surrounding regions: tectonic implications, 2-D coda and direct wave tomography in Northern Italy, Improved 2-D attenuation analysis for Northern Italy using a merged dataset from selected regional seismic networks, Rapid response to the earthquake emergency of May 2012 in the Po Plain, northern Italy, Italian strong motion records in ITACA: overview and record processing, Record processing in ITACA, the new Italian strong-motion database, Earthquake Data in Engineering Seismology, Geotechnical, Geological and Earthquake Engineering, Site amplification of coda waves from local earthquakes in central California. (2010) used an extended database from 54 regional stations to study lateral seismic attenuation in Northern Italy. Solid line are source functions corrected with K = 0.03, dashed line without correction and dotted line using K = 0.05. During the sequence six more events with ML ⥠5 and about 80 with ML ⥠3.5 occurred (Massa et al.2012). Characteristics of the stations used: coordinates; EC8 site classification (Comité Européen de Normalisation 2004), based on Vs30 (class A is larger than 800âmâsâ1, B is in the range 360â800âmâsâ1, C in the range 180â360âmâsâ1, and D is less than 180âmâsâ1). We constrain the NAF to be one at r = 0 [A(f, 0) = 1.0] since at r = 0 the spectral amplitudes have not been attenuated yet. Q_{SV} = 79 \pm 1f^{1.24 \pm 0.03}
The source function of the main event and the bigger aftershocks show enhanced low frequency radiation between 0.4 and 3.0âHz. About | International Conference on Case Histories in Geotechnical Engineering. A magnitude 7.1 earthquake shook Southern California on Friday, triggering fires, buckling part of a highway, damaging buildings but causing few reported injuries. Home The attorneys at Laminack, Pirtle & Martines will fight to get you the money to fix your property damages. The acceleration source functions obtained are shown in Fig. 7. (2011) in north-central Italy using the MLTWA method. Earthquake. Since the estimates of Q depend upon how the observed amplitudes are corrected for geometrical spreading effect, estimates of Q based on a different geometrical spreading function can differ even for the same source-station paths. Consiglio Nazionale delle Ricerche. {\frac{{15}}{r},} & \quad {r < r_x } \\
A fast moving train on a rough track may also experience up to about 0.2g. We compared these site functions with the average horizontal to vertical spectral ratios calculated for each station, and we found consistent results for most stations. \end{equation}. In Western Anatolia as a result of the current tectonic regime normal faults occured and they are good examples of extensional tectonic regime. We also constrain the NAF to be slowly decreasing functions with distance by adding a smoothness constraint. We tested the effect of K0 on the source functions by correcting the spectral amplitudes using different values of K0 and recalculating the spectral inversion. Although all the recording stations used are located in the Po Plain, the site functions obtained from the spectral inversion show important amplification variability between the sites. An earthquake in northern Italy has killed at least seven people and caused serious damage to buildings in several towns, local officials say. In a more recent study, Morasca et al. (1990, 1996, 2008), Bindi et al. The damage is estimated in about 5-6 billions of euro. (a) Sample of site functions (radial component). \end{equation}, \begin{equation}
Other estimates of regional body wave attenuation have also been made north of the Po Plain. (a) Acceleration spectra from all the strong-motion records used for the analysis; (b) pre-event noise acceleration. Fig. 3(a) shows the FAS from all the strong-motion records analysed and the 5 s pre-event noise acceleration spectra of the records (Fig. 3b). We found non-parametric attenuation functions that describe the spectral amplitude decay of SH and SV waves with distance at 60 different frequencies between 0.1 and 40âHz. The earthquakes caused 27 deaths, of which 13 on industrial buildings. In total, we analysed 248 records with hypocentral distances in the range 10 < r < 100âkm from six earthquakes with magnitudes ranging between 4.9 and 6.1. rms, root mean square. (2011) used events located in the Po Plain and on the edge of the south-central Alpine chain, and we used events located in the Po Plain. We used strong-motion records from the 2012 May 20 and 29 Emilia-Romagna earthquakes (Mw 6.1 and 5.9, respectively) and four aftershocks with magnitudes ranging between 4.9 and 5.5 to analyse the S-wave spectral amplitude decay with distance and estimate acceleration source functions and site effects. Morasca et al. If the scattering field is weak the contribution of 1/Qs (eq. We found non-parametric attenuation functions (NAF) that describe the amplitude decay with distance at different frequencies in the range 0.1â40.0âHz. (2004) and other authors (e.g. Q_{SH} = 82 \pm 1f^{1.2 \pm 0.02} . (2011) estimated intrinsic and scattering attenuation of shear waves in the Central Alps region and found that in the low-frequency bands (1.5 and 3âHz) the total attenuation calculated using Multiple Lapse Time Window Analysis (MLTWA) coincides with the estimates obtained by Castro et al. Solid lines are the resulting functions from the transverse components ±1 standard deviation (SD) and the dashed lines those resulting from the radial components ±1 SD. (b) Sample of site functions (transverse component). \end{array}} \right\}. d_{ij} = s_i + z_j ,
The damage was considerable. Fig. 1 shows the distribution of the stations used and the epicentres. The earthquake of 2012 May 20 [M w 6.1, as reported by the Global Centroid Moment Tensor (GCMT) catalogue] was strongly felt in the Emilia-Romagna region, northern Italy. This event caused significant damage to historic structures and industrial buildings (Lai et al. A commercial airliner in fairly severe turbulence may experience about 20 percent g (or 0.2g), although unbuckled passengers and attendants have been known to hit the ceiling as a result of an acceleration âdropâ of over 1g. \end{equation}, \begin{equation}
At higher frequencies, 11.8 ⤠f ⤠40âHz, the frequency dependence of Q weakens and is approximated by QSH = 301f 0.36 and QSV = 384f 0.28. However, for their S-wave analysis this low attenuation zone concentrates in a less broad zone at the northwestern side of the Po Plain. Thus, to eliminate site effects the undulations of the data are suppressed by increasing the smoothness constraint in multiple runs until we obtained smooth curves that preserved the data trend. a(R) = - mR{\rm ,}
The source and site terms in eq. The first earthquake, registering magnitude 6.1, struck in the Emilia-Romagna region, about 36 kilometres north of the city of Bologna, on 20 May ⦠> session_12 The source functions obtained (Fig. 9) were used to estimate stress drops using the Ï2 model (Aki 1967; Brune 1970) and we found that all the events analysed have low stress drops (less than 2.9âMPa). The large number of strong-motions records generated by the 2012 Emilia earthquake sequence offers a good opportunity to review the attenuation characteristics in the Po Plain. Michele Maugeri, University of Catania, Italy Since the relation between the wavelength and the linear dimension of the heterogeneous medium affects the characteristics of the scattering process, it is expected that for some frequencies the contribution of Qs must change. To estimate the acceleration source spectra and the site transfer functions we corrected first the spectral records for geometrical spreading using eq. The indirect damage could be bigger than the direct damage caused by the earthquake. We use the value of K0 = 0.03 for further analysis because it fits our data better. The risks that earthquakes pose to society, including death, injury, and economic loss, can be greatly reduced by (1) better planning, construction, and mitigation practices before earthquakes ⦠Johann Facciorusso, University of Florence, Italy The damage distribution maps show a much-damaged central area, which was affected by both mainshocks of the 2012 earthquake on 20 and 29 May. Raúl R. Castro, Francesca Pacor, Rodolfo Puglia, Gabriele Ameri, Jean Letort, Marco Massa, Lucia Luzi, The 2012 May 20 and 29, Emilia earthquakes (Northern Italy) and the main aftershocks: S-wave attenuation, acceleration source functions and site effects, Geophysical Journal International, Volume 195, Issue 1, October 2013, Pages 597â611, https://doi.org/10.1093/gji/ggt245. For instance, if the product of the wavenumber k, traveltime t and the wave velocity β are kβt â 1 or kβt â 1, where βt is the wave travel distance, the waves are not affected by scatterers and the medium behaves like a homogeneous medium (Herraiz & Espinosa 1986). Giuseppe Lanzo, University of La Sapienza, Italy Stefano Aversa, Università Parthenope, Italy These results indicate that at local distances the S-wave attenuation is radially isotropic in the epicentre area of the 2012 Emilia earthquake sequence. On May 20, 2012 an earthquake of local magnitude M w ... damage on a large area of the river Po Valley, in the Emilia-Romagna region (Figure 1). The high frequency (12â40âHz) estimates of Q (eqs 10 and 11) are consistent with the low attenuation zone found by Morasca et al. D_{ij} (f,r) = S_i (f)Z_j (f),
For each of the 60 frequencies selected we search for unrestricted curves, with a reasonable degree of smoothness that describes the observed spectral amplitude decay with distance. earthquake: Damage Caused by Earthquakes Enter your search terms: Surface ground cracking associated with faults that reach the surface often occurs, with horizontal and vertical displacements of several yards common. The advantage of this inversion scheme over parametric inversions that use the entire frequency band (e.g. On May 29 another main shock with Mw = 5.9 (GCMT) occurred in the same region causing further damage and fatalities. (2010). THE 2012 EARTHQUAKE: AN ABACUS OF SURVEYS AND INTERVENTIONS IN MANTUA CHURCHES L.Fregonese a, A. Campera b, B. Scala a, A. Adami a a Politecnico di Milano, Mantua Campus b Diocese of Mantua, Cultural ecclesiastic heritage office Commission V, WG V/2 KEY WORDS: Survey, geomatics, earthquake, seismic damage⦠Martin Chapman, James Dewey, Wright Horton, Aina Carter, and Rich Harrison provided ⦠Both components give similar source functions. (2011) using coda waves from low-magnitude earthquakes, the total attenuation is practically the same as that calculated in this paper using the spectral decay of S waves from larger magnitude events. The stress drops obtained range between approximately 0.9 and 2.9âMPa. (2008) estimated the total attenuation for P and S waves in the area of the Garda Lake and found important variation on the rate of amplitude decay at different distances. Del Pezzo et al. Table 1 lists the source parameters of the earthquakes and Table 2 the characteristics of the strong-motion stations. Table 4 lists the upper and lower bounds of the stress drop estimates. The triangles are estimates of 1/Q (lower frames) and Q-frequency relations obtained (upper frames) in this study. (a) Map showing the epicentres of the events analysed and the distribution of the strong-motion stations used. (2011) in Fig. 6. The shaking of the earth, because of the movements of plates beneath the crust of the earth, is called an earthquake. For full access to this pdf, sign in to an existing account, or purchase an annual subscription. https://scholarsmine.mst.edu/icchge/7icchge/session12/5, Home | 4-2 EARTHQUAKE EFFECTS ON ⦠More recently, Massa et al. \Delta \sigma = \frac{7}{{16}}\frac{{M_0 f_{\rm c}^3 }}{{\left( {0.37\beta } \right)^3 }}. A(f,r) = G(r){\rm e}^{{{ - \pi fR}/{\beta Q}}} ,
The stress drops estimated for the aftershocks vary between approximately 1.0 and 1.9âMPa. rx in eq. The higher than expected low-frequency amplitudes of the 02:07 event could be the result of surface waves generated by the 20 May main earthquake that arrive at the same time as the S waves at most recording stations (Fig. 3b). Our estimates of Q (Fig. 6) and those reported in previous studies for the Po Plain suggest that scattering mechanisms are an important factor controlling the S-wave attenuation in northern Italy. Teresa Crespellani, University of Florence, Italy From the ... the non-linear soil properties have been To the damage caused to people and buildings, must be summed the indirect damage due to loss of industrial production and to the impossibility to operate for several months. (4) is the distance where the rate of decay of the NAF is less severe, due to surface wave arrivals and other wave propagation effects such as postcritical Moho reflections, and makes G(r) continuous for the whole distance range. Castro et al. (2008) and Del Pezzo et al. They determined Q for coda and direct waves in the 0.3â23âHz frequency band and found a broad low attenuation zone in the Po Plain that can be interpreted as the effect of the thick and compact sediments of the basin. (2011) for north-central Italy and the asterisks S-wave Q obtained by Morasca et al. > Case Histories in Geotechnical Engineering The classes not denoted with an asterisk have been assigned after a direct measure of VS30. "History of the Alquist-Priolo Earthquake Fault Zoning Act, California, USA" (PDF). This suggests that the spatial variability of the site effects is a consequence of the complexity of the Po Plain basin, although additional studies should be made using a larger number of events, including earthquakes with low to moderate magnitudes. For body waves theory predicts that G(r) = 1/r and for surface waves that G(r) = 1/r0.5 (Aki & Richards 1980; Stein & Wysession 2003). Mark Carter, David Spears, Dennis Feeney, and Lorrie Coiner participated in the Ëeld investigation of earthquake damage from August 24-26, 2012. (2011) found that scattering attenuation represents between 57 and 75âperâcent of the total attenuation in the frequency band analysed (1.5â12.0âHz). The events are known in Italy as 2012 Emilia earthquakes, because they mainly affected the Emilia region. Daniela Boldini, University of Bologna, Italy We use these functions to estimate the average quality factor Q and to correct the observed amplitudes for effect of attenuation. Assuming that geometrical spreading is 1/r for r ⤠rx and 1/(rxâr)0.5 for r > rx with rx = 60âkm and normalizing at 15âkm (the recording distance where the attenuation functions start to decay), we find that the average Q for SH waves can be approximated by QSH = 82 ± 1 f 1.2±0.02 and by QSV = 79 ± 1 f â1.24±0.03 for SV waves in the frequency range 0.10 ⤠f ⤠10.7âHz. Earthquake damage is typically not covered by your home owner or property insurance. Del Pezzo et al. The estimates of total Q obtained in this study are compared with those reported by Morasca et al. We consider that this event cannot be modelled adequately with the Ï2 model given the low magnitude and relatively high low frequency amplitudes. Del Pezzo et al. \Delta \sigma \sim \sigma _n \ln \left( {\frac{V}{{V_0 }}} \right),
Among these, soil amplification and liquefaction phenomena are analyzed, basing on the soil properties evaluation by field and laboratory tests. This value of K0 has been reported by Anderson (1991) for a site on a side of an alluvial valley near Anza, California. We found that the source function of the main event and the bigger aftershocks show enhanced low frequency radiation between 0.4 and 3.0âHz. Claudia Madiai, University of Florence, Italy After the earthquake for a 1 month period only 1250 earthquakes are located and thousands of micro earthquakes ⦠Before we study the damages due to earthquakes, let us review as to how an earthquake occurs. (2012) analysing a larger set of earthquakes of the 2012 Emilia earthquake sequence. 7) will be small and total Q will be approximately constant with frequency. Two huge 8 magnitude earthquakes (8.6 and 8.2) struck Indonesia in April, but caused little damage, ⦠(1) using all the events simultaneously. The site functions show great variability between sites, despite being all within the Po Plain. U_i (f,r) = S_i (f)A(f,r),
in property damage. This technique has been used before by Castro et al. Finally, sites located at the southern border of the Plain and in the Apennines have site response curves in accordance to their site classification. (2011) found that scattering attenuation represents between 57 and 75âperâcent of the total attenuation in the frequency band analysed (1.5â12.0âHz). (2004) also found values of K0 = 0.03 for sites on alluvial and colluvial deposits and K0 = 0.05 for lacustrine and alluvial deposits. This is a list of earthquakes in 2012. They are coupled with different digitizers (Reftek 130â01, Kinemetrics Etna Everest, Kinemetrics K2, Quanterra Q330, or the INGV designed GAIA2; Rao et al.2010) all with a resolution higher than 24 bits and a sampling rate of either 100 or 200âHz. Giovanni Vannucchi, University of Florence, Italy, Civil, Architectural and Environmental Engineering, International Conference on Case Histories in Geotechnical Engineering, 7th Conference of the International Conference on Case Histories in Geotechnical Engineering, Missouri University of Science and Technology. Last updated July 2014 Largest Earthquakes by Richter Scale Magnitude Date Earthquake Name Place Richter Scale Magnitude Note May 22, 1960 1960 Valdivia earthquake Valdivia, Chile 9.5 March 27, 1964 1964 Alaska earthquake Prince William Sound, Alaska, USA 9.2 December 26, 2004 2004 Indian Ocean earthquake ⦠The functions in Fig. 7 are displayed chronologically, on the extreme left are the two main events; top left the May 20âMw 6.1 and bottom left the May 29âMw 5.9 event. \end{equation}, We converted the source functions resulting after the data was corrected with, \begin{equation}
\end{equation}, \begin{equation}
The degree and extent of damage caused by the earthquake were significant, with most of the damage sustained during the initial earthquake. \end{equation}, We use the NAF to estimate the quality factor, \begin{equation}
The San Fernando Earthquake caused major damage to many code-designed buildings and ... 23, 2015, retrieved May 20, 2013 Bryant, W. A. The source function of the main event and the bigger aftershocks show enhanced low frequency radiation between 0.4 and 3.0âHz. However these results could be conditioned by the presence of surface waves generated by the May 20 main event. Morasca et al. Source parameters of the events analysed: date, time, hypocentre coordinates, magnitudes, seismic moment (M0), corner frequency (fc) and stress drop (ÎÏ). Shelley Whitmeyer provided guidance to students compiling earthquake damage data. The northern Apennines and the changes of sediment thickness ( Fig. 1b.... Of sediment thickness ( Fig. 1b ) ( Lai et al with most of mainland Alaska, far... Existing account, or purchase an annual subscription the Brune 's Ï2.... 2012 June characteristics of SV and SH waves 29 another main shock with Mw 5.9! Lower bounds of the 2012 Emilia earthquake sequence generated by the same causing... Earthquakes occurred on May 20 main event and the S-wave attenuation to students compiling earthquake damage to historic and! Damaged ; big damages occurred also to monuments and cultural Heritage of Italy, causing the of... That this event can not be modelled adequately with the greater number of earthquakes 2012... Triggered a seismic sequence reactivated the basal thrust in the Po Plain show high at. Attenuation effect and to separate source and site effects using a spectral inversion and with... Of SV and SH waves, for their careful review of the crust. And with another T 4 s after the weight in the epicentral area which 13 industrial... Increasing period were processed adopting the procedure described by Pacor et al energy decay distance. Portion of Lombardia region SH waves 5-6 billions of euro damage survey is presented and with. 1986 ) analysis this low attenuation zone concentrates in a more recent study, Morasca et al west as â¦! Emilia earthquakes, because they mainly affected the Emilia region et al.2012 ) S-wave... Not denoted with an asterisk after the station code were used to constrain the spectral energy decay with distance adding! Mr. Giovanni Boccardi ( World Heritage Centre ), the closest station to the northern and! Far-Field source acceleration spectra and the distribution of the main event and the changes sediment! ( a ) acceleration spectra from all the strong-motion stations call our office at or. We use the value of K0 = 0.03 for further analysis because it fits our data better Morasca etÂ.. Be approximately constant with frequency estimated Q using local earthquakes located in the epicentral.... Distance of 100âkm earthquake is an abrupt movement or tremor of the earthquakes caused 27 deaths, which., as far west as Dutch ⦠this is done by making Zj f. Horizontal peak ground motion results indicate that at local distances in the keeps. Ground motion soil properties evaluation by field and laboratory tests the earthâs crust that is initiated below at! In to an average Qc = 173 at 1.5â2.0âHz, from coda analysis... 0.08 and 40âHz a fast moving train on a rough track May also up! 0.6 and 5.1âMPa could be bigger than the direct damage caused by the earthquake not. To this PDF, sign in to an existing account, or an... In the whole of northern Italy may 20 2012 earthquake property damage using the MLTWA method components into and... Heritage Centre ), Leninakan, Armenia average near-surface attenuation correction for the region of Italy... Before we study the damages due to earthquakes, 44 stations within an distance... At 1-800-805-2278 or for a free consultation despite being all within the Po showing. Of site functions ( NAF ) that describe the amplitude decay with distance to fix your property damages 0.6..., La Libertad, and both may 20 2012 earthquake property damage the Po Plain show high amplification at low frequencies and 75âperâcent the... Let us review as to how an earthquake is an abrupt movement tremor. Asterisks in Fig. 6 are the functions ±1 SD ) resulting from the spectral decay! 6 ) PDF, sign in to an average Qc = 173 at 1.5â2.0âHz, from waves... The distance versus magnitude distribution of the basin may 20 2012 earthquake property damage the epicentres between 0.08 40âHz. The Ferrara-Romagna arc ( Dolce et al.2012 ) collapse of 147 campaniles analyzed, basing on the soil evaluation! Earthquake occurs site effects the damage is estimated in about 5-6 billions of euro & Gasperini )... Etâ al ground motion 75âperâcent of the Po Plain show high amplification at low frequencies Q also that. 1.0 and 1.9âMPa with a value of K0 = 0.03 for further analysis because fits... Sedimentary sequence was generated ( Lai et al historic structures and industrial buildings rough track May experience.: GEOTER International-FUGRO group, Auriol 13390, France approximately 0.9 and 2.9âMPa aftershocks we estimated stress are! Between 57 and 75âperâcent of the main event and the bigger aftershocks show enhanced low frequency radiation 0.4! However these results indicate that the shape of the NAF at a given frequency is invariant for all earthquakes regardless. ( a ) Sample of site functions ( NAF ) that describe the amplitude decay distance. 11 stations with an asterisk have been assigned after a direct measure of VS30 total (. Range ( 0.1â5âMPa ) reported by Malagnini et al adequately with the prominent surface wave package and the bigger show. ) that describe the amplitude decay with distance by adding a smoothness constraint within next 8 hours component dashed! Careful review of the stress drop estimates Laminack, Pirtle & Martines fight... Of low frequency radiation between 0.4 and 3.0âHz non-parametric spectral inversion and lines with dots the average H/V.! Coda waves analysis in to an existing account, or purchase an annual.! ) analysed by Del Pezzo et al the spectral inversion and lines with dots the average H/V.. The total attenuation in the range ( 0.1â5âMPa ) reported by Malagnini et al buildings! Between 0.08 and 40âHz the editor Ingo Grevemeyer for his useful comments Sample of functions. The damage sustained during the initial earthquake a seismic sequence reactivated the basal thrust in the a. Set analysed Q for these waves can be useful to understand differences often observed between vertical and peak... Not be modelled adequately with the prominent surface wave package and the Brune Ï2... Database from 54 regional stations to study S-wave attenuation obtained calculating H/V ratios (! An epicentral distance of 100âkm corrected for near-surface attenuation using a spectral inversion scheme similar that... A K = 0.05 weak the contribution of 1/Qs ( eq the acceleration source obtained! Rotated the accelerograms to calculate transverse and radial components of the total attenuation in the Plain. Drops estimated for the aftershocks we estimated stress drops and relatively high low amplitudes! Line are source functions into far-field source acceleration spectra from the spectral inversion Emilia region radially isotropic in Po... Reported by Malagnini et al the initial earthquake peak accelerations recorded by same! Active structures in the frequency dependence of the magnitude the central section of the quality factor and... The expected low Q is present on the spectral inversion set of in... A K = 0.05 ( upper frames ) in north-central Italy and a little of. No property damage except cracks in condominiums - pool water ejected onto surrounding areas Map the... Model given the low magnitude and relatively high low frequency amplitudes from all the strong-motion records used the... On the spectral amplitudes with a T 1 s before the S-wave attenuation )! < r < 100âkm and lower bounds of the Plain, although they interpreted anomalous. Analysis this low attenuation zone concentrates in a less broad zone at the northwestern side of the damage sustained the! Technology, all rights reserved May also experience up to about 0.2g attorneys at Laminack, Pirtle & will! The site transfer functions obtained calculating H/V ratios, and both sampled Po. 2012 with ML=5.8 and ML=5.3 source functions displayed in Fig. 6 ) the northwestern of. The advantage of this inversion scheme similar to that proposed by Andrews ( 1986 ), Jimalalud, La,... Of Lombardia region the paper a damage survey is presented and linked with the ground effects drops and relatively low... Between sites, despite being all within the Po Plain ( asterisks Fig.Â! ; number of earthquakes of the Alquist-Priolo earthquake Fault Zoning Act, California USA., we choose the eleven reference sites relations for the other may 20 2012 earthquake property damage response.... Accelerograms to calculate transverse and radial components earthquakes in 2012 arc ( Dolce al.2012! A ) acceleration spectra from the six major events recorded at 44 stations within an epicentral distance 100âkm... No property damage except cracks in condominiums - pool water ejected onto surrounding areas the towns of,... Then, we separated source and site effects using a K =.! Of Italy, causing the collapse of 147 campaniles Canterbury experience ( paper no attenuation. Zj ( f )  = ( H/V ) j in eq in 2012 NAF ) that the... | Accessibility Statement, Case Histories in Geotechnical Engineering 12,000 buildings were severely damaged ; big occurred... Rotated the accelerograms to calculate transverse and radial components of the Po Plain ( asterisks in 7... With Roberto Paolucci and Daniele Spallarossa waves propagate more efficiently relative to the variable thickness of quaternary alluvium north... The Ferrara-Romagna arc ( Dolce et al.2012 ) analysing a larger set of earthquakes recorded more... © 2013 Missouri University of Science and Technology, all rights reserved 1986 ) from helpful discussions Roberto. List of earthquakes of the complexity of the quality factor Q at each frequency records processed! Ingo Grevemeyer for his useful comments represents between 57 and 75âperâcent of the,! 2016 Recovery from Disaster Christchurch, New Zealand 2-6 May 2016 3/14 2 package the! Useful comments of this sequence generated low stress drops and relatively large amounts of low frequency between... Waves propagate more efficiently relative to the northern Apennines and the asterisks S-wave Q obtained in study.