Correlation of Spectral Acceleration Values of Mainshock-Aftershock Ground Motion Pairs

2019 ◽  
Vol 35 (1) ◽  
pp. 39-60 ◽  
Author(s):  
Athanasios N. Papadopoulos ◽  
Mohsen Kohrangi ◽  
Paolo Bazzurro
Keyword(s):  
Ground Motion ◽  
Seismic Hazard Assessment ◽  
Statistical Correlation ◽  
Spectral Acceleration ◽  
Substantial Evidence ◽  
Period Range ◽  
Selection For ◽  
Spectral Accelerations ◽  
Record Selection ◽  
The Impact

This study examines the statistical correlation between the spectral accelerations of mainshock-aftershock ground motion pairs in the NGA-West2 ground motion database. Aftershock spectral accelerations are found mildly correlated with their mainshock counterparts for closely spaced periods of vibration and are weakly correlated over the rest of the period range. We further investigate for potential differences between the interperiod correlations of mainshock and aftershock spectral accelerations, finding no substantial evidence to support the use of different models for the two cases. Furthermore, the impact of different rupture scenario parameters on correlation is examined and discussed. The derived correlation estimates are expected to aid in aftershock seismic hazard assessment and/or in record selection for risk assessment applications by using the mainshock spectral ordinates to obtain better predictions for the aftershock ground motion.

Conditional spectrum-based ground motion record selection using average spectral acceleration

2017 ◽  
Vol 46 (10) ◽  
pp. 1667-1685 ◽  
Author(s):  
Mohsen Kohrangi ◽  
Paolo Bazzurro ◽  
Dimitrios Vamvatsikos ◽  
Andrea Spillatura
Keyword(s):  
Ground Motion ◽  
Spectral Acceleration ◽  
Record Selection ◽  
Ground Motion Record Selection

scholarly journals What is the impact of the August 24, 2016 Amatrice earthquake on the seismic hazard assessment in central Italy?

2016 ◽  
Vol 59 ◽  
Author(s):  
Maura Murru ◽  
Matteo Taroni ◽  
Aybige Akinci ◽  
Giuseppe Falcone
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
Central Italy ◽  
Seismic Hazard Assessment ◽  
Motion Prediction ◽  
Ground Motion Prediction Equations ◽  
Prediction Equations ◽  
Ground Motion Prediction ◽  
The Impact

<p>The recent Amatrice strong event (M<sub>w</sub>6.0) occurred on August 24, 2016 in Central Apennines (Italy) in a seismic gap zone, motivated us to study and provide better understanding of the seismic hazard assessment in the macro area defined as “Central Italy”. The area affected by the sequence is placed between the M<sub>w</sub>6.0 1997 Colfiorito sequence to the north (Umbria-Marche region) the Campotosto area hit by the 2009 L’Aquila sequence M<sub>w</sub>6.3 (Abruzzo region) to the south. The Amatrice earthquake occurred while there was an ongoing effort to update the 2004 seismic hazard map (MPS04) for the Italian territory, requested in 2015 by the Italian Civil Protection Agency to the Center for Seismic Hazard (CPS) of the Istituto Nazionale di Geofisica e Vulcanologia INGV. Therefore, in this study we brought to our attention new earthquake source data and recently developed ground-motion prediction equations (GMPEs). Our aim was to validate whether the seismic hazard assessment in this area has changed with respect to 2004, year in which the MPS04 map was released. In order to understand the impact of the recent earthquakes on the seismic hazard assessment in central Italy we compared the annual seismic rates calculated using a smoothed seismicity approach over two different periods; the Parametric Catalog of the Historical Italian earthquakes (CPTI15) from 1871 to 2003 and the historical and instrumental catalogs from 1871 up to 31 August 2016. Results are presented also in terms of peak ground acceleration (PGA), using the recent ground-motion prediction equations (GMPEs) at Amatrice, interested by the 2016 sequence.</p>

Hazard Disaggregation and Record Selection for Fragility Analysis and Earthquake Loss Estimation

2017 ◽  
Vol 33 (2) ◽  
pp. 529-549 ◽  
Author(s):  
Luis Sousa ◽  
Mário Marques ◽  
Vitor Silva ◽  
Humberto Varum
Keyword(s):  
Ground Motion ◽  
Limit State ◽  
Fragility Analysis ◽  
Economic Losses ◽  
Earthquake Risk ◽  
Structural Class ◽  
Ground Motion Selection ◽  
Record Selection ◽  
Hazard Disaggregation ◽  
The Impact

Economic losses and collapse probability are critical measures for evaluating the earthquake risk of existing buildings. In this context, this study sheds light on several problems and limitations in current practice of hazard-consistent ground-motion selection and fragility analysis, focusing on the impact that (commonly assumed) approximations in disaggregation outputs have on the aforementioned risk metrics, as opposed to an exact solution. These issues are investigated for several building classes, seismicity models and ground motion prediction equations (GMPE), for a site in the city of Lisbon (Portugal). It is observed that only an exact (i.e., rupture-by-rupture) disaggregation can lead to satisfactory results in terms of accuracy, when limit state criteria are not structure-specific. On the other hand, an approximate method is proposed, which still leads to statistically valid results regardless of the chosen structural class, seismicity model or GMPE.

scholarly journals Updated Probabilistic Seismic Hazard Assessment of Pakistan

2021 ◽  
Author(s):  
Muhammad Waseem ◽  
Mustafa Erdik
Keyword(s):  
Ground Motion ◽  
Seismic Hazard Assessment ◽  
Motion Prediction ◽  
Probabilistic Seismic Hazard Assessment ◽  
Maximum Magnitude ◽  
Spectral Acceleration ◽  
Ground Motion Prediction Equations ◽  
Ground Motion Prediction ◽  
Logic Tree ◽  
Probability Of Exceedance

Abstract Probabilistic seismic hazard assessment of Pakistan is carried out to compute hazard in terms of peak ground acceleration (PGA) and spectral acceleration (SA) for 975 and 2475 years return periods. A composite earthquake catalogue consisting of 32,700 events has been compiled having a magnitude range of Mw 4.0-8.2 in this study and used in the analysis to make computations at a rectangular grid of 5 km in the OpenQuake plateform. Ground motion values have been obtained for flat rock reference seismic site conditions with shear wave velocity of 760 m/s. The epistemic uncertainties inherent in ground motion prediction equations and maximum magnitude potential of seismic sources are taken into account through logic tree. Ground motion prediction equations are assigned equal weights in the logic tree while different various weight are assigned to the maximum magnitude potential models. Results of the study are expressed as ground motion contour maps, mean uniform hazard spectra for important cities in Pakistan. PGA ranges from 0.16 to 0.54g for 10 % of probability of exceedance, 0.23 to 0.72g of probability of exceedance 0.32 to 1.02 g for 2 % of probability of exceedance in 50 years. Spectral acceleration at 0.2 s range from 0.67 to 2.19g for 2% chance of exceedance in 50 years, respectively. While spectral acceleration at 1.0 s values range from 0.09 to 0.52g 2% chance of exceedance in 50 years. Comparison of results of this study with other well regarded references of suggest that results of the study are rational and are reliable.

Impact of partially non-ergodic site-specific probabilistic seismic hazard on risk assessment of single buildings

2020 ◽  
pp. 875529302093881
Author(s):  
Mohsen Kohrangi ◽  
Sreeram Reddy Kotha ◽  
Paolo Bazzurro
Keyword(s):  
Risk Assessment ◽  
Ground Motion ◽  
A Priori ◽  
Real Life ◽  
Site Specific ◽  
Risk Estimates ◽  
The Difference ◽  
Record Selection ◽  
Ground Motion Record Selection ◽  
The Impact

The growth of global ground-motion databases has allowed generation of non-ergodic ground-motion prediction equations (GMPEs) based on specific on-site recordings. Several studies have investigated the differences between the hazard estimates from ergodic versus non-ergodic GMPEs. Here instead we focus on the impact of non-ergodic PSHA estimates on the seismic risk of nonlinear single-degree-of-freedom systems representing ductile structures and compare it with the traditional risk estimates obtained using ergodic GMPEs. The structure-and-site-specific risk estimates depend not only on the difference in the hazard estimates but also on the different hazard-consistent ground-motion record selection that informs the response calculation. The more accurate structure-and-site-specific non-ergodic risk estimates show that traditional ones may be biased in a way impossible to predict a priori. Hence, the use of the non-ergodic approach is recommended, whenever possible. However, further advancements of non-ergodic GMPEs are necessary before being routinely utilized in real-life risk assessment applications.

Mainshock‐consistent ground motion record selection for aftershock sequences

2020 ◽  
Vol 49 (8) ◽  
pp. 754-771 ◽  
Author(s):  
Athanasios N. Papadopoulos ◽  
Mohsen Kohrangi ◽  
Paolo Bazzurro
Keyword(s):  
Ground Motion ◽  
Aftershock Sequences ◽  
Selection For ◽  
Record Selection ◽  
Ground Motion Record Selection

scholarly journals Conditional spectrum based ground motion record selection using average spectral acceleration

2017 ◽  
Vol 47 (1) ◽  
pp. 265-265 ◽  
Author(s):  
Mohsen Kohrangi ◽  
Paolo Bazzurro ◽  
Dimitrios Vamvatsikos ◽  
Andrea Spillatura
Keyword(s):  
Ground Motion ◽  
Spectral Acceleration ◽  
Record Selection ◽  
Ground Motion Record Selection

Satellite thermal monitoring of Balkan region by means of Robust Satellite Techniques: the case of Albania (26 November 2019, Mw 6.4) earthquake

2020 ◽  
Author(s):  
Valerio Tramutoli ◽  
Nicola Genzano ◽  
Roberto Colonna ◽  
Carolina Filizzola ◽  
Mariano Lisi ◽  
...  
Keyword(s):  
Seismic Hazard Assessment ◽  
Statistical Correlation ◽  
Thermal Monitoring ◽  
Short Term ◽  
The Earth ◽  
Satellite Sensors ◽  
Balkan Region ◽  
Casual Relation ◽  
The Impact

&lt;p&gt;Since 2001, Robust Satellite Techniques (RST; Tramutoli 1998, 2007) has been used to study - by analyzing long-term TIR observations provided by passive satellite sensors - the enhancement of the Earth thermally emitted radiation, possibly related to seismic activities.&lt;/p&gt;&lt;p&gt;Such an approach has demonstrated to be able (especially when applied to geostationary satellite radiances) to isolate TIR anomalies possibly related to earthquake occurrence from those expected as a consequence of others natural (e.g. meteorological) or observational (e.g. measurement time and/or place) sources. Among the others TIR anomalies, those more significant (in term of Signal/Noise ratio), extended (in space) and persistent (in time) have been considered (SSTAs, Significant Sequence of TIR Anomalies, Eleftheriou et al., 2016) for further analyses. Up to now, long-term statistical correlation analyses between seismic events and RST-based SSTAs carried out in different European seismic regions (i.e. Greece, Italy and Turkey by using MSG-SEVIRI) highlights that the 75% of SSTAs are in apparent space-time relation with earthquakes with magnitude greater than 4. In all testing regions/periods a non-casual relation has been found.&lt;/p&gt;&lt;p&gt;In this paper, we will show the results achieved by real-time thermal monitoring over Albania region at time of the strong earthquake of magnitude Mw 6.4 occurred on 26 November 2019. Moreover, we will discuss about the impact of the use of the &quot;RST-based satellite TIR anomalies&quot; parameter in the framework a multi-parametric system devote to the seismic hazard assessment in the short-term.&lt;/p&gt;

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