Probabilistic Seismic Hazard Assessment (PSHA) for Lesvos Island Using the Logic Tree Approach

We carry out a probabilistic seismic hazard assessment (PSHA) for Lesvos Island, in the northeastern Aegean Sea. Being the most populated island in the northern Aegean Sea and hosting the capital of the prefecture, its seismic potential has significant social-economic meaning. For the seismic hazard estimation, the newest version of the R-CRISIS module, which has high efficiency and flexibility in model selection, is used. We incorporate into the calculations eight (8) ground motion prediction equations (GMPEs). The measures used are peak ground acceleration, (PGA), peak ground velocity, (PGV), and spectral acceleration, (SA), at T=0.2 sec representative of the building stock. We calculate hazard curves for selected sites on the island, sampling the southern and northern parts: Mytilene, the capital, the village of Vrisa, Mithymna and Sigri. Hazard maps are also presented in terms of all three intensity measures, for a mean return period of 475 years (or 10% probability of exceedance in 50 years), assuming a Poisson process. Our results are comparable to the predictions of on-going EU hazard models, but higher than the provisions of the Greek Seismic Code. Finally, we perform disaggregation of hazard to depict the relative contribution of different earthquake sources and magnitudes to the results.

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Probabilistic seismic hazard assessment in Greece – Part 1: Engineering ground motion parameters

Natural Hazards and Earth System Science ◽

10.5194/nhess-10-25-2010 ◽

2010 ◽

Vol 10 (1) ◽

pp. 25-39 ◽

Cited By ~ 4

Author(s):

G-A. Tselentis ◽

L. Danciu

Keyword(s):

Seismic Hazard ◽

Hazard Assessment ◽

Peak Ground Acceleration ◽

Seismic Hazard Assessment ◽

Peak Ground Velocity ◽

Probabilistic Seismic Hazard Assessment ◽

Probabilistic Seismic Hazard ◽

Arias Intensity ◽

Ground Acceleration ◽

Cumulative Absolute Velocity

Abstract. Seismic hazard assessment represents a basic tool for rational planning and designing in seismic prone areas. In the present study, a probabilistic seismic hazard assessment in terms of peak ground acceleration, peak ground velocity, Arias intensity and cumulative absolute velocity computed with a 0.05 g acceleration threshold, has been carried out for Greece. The output of the hazard computation produced probabilistic hazard maps for all the above parameters estimated for a fixed return period of 475 years. From these maps the estimated values are reported for 52 Greek municipalities. Additionally, we have obtained a set of probabilistic maps of engineering significance: a probabilistic macroseismic intensity map, depicting the Modified Mercalli Intensity scale obtained from the estimated peak ground velocity and a probabilistic seismic-landslide map based on a simplified conversion of the estimated Arias intensity and peak ground acceleration into Newmark's displacement.

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The Effects of Aleatory Variabilities of Seismicity on Probabilistic Seismic Hazard Assessment

Bulletin of the Seismological Society of America ◽

10.1785/0120190278 ◽

2020 ◽

Vol 110 (3) ◽

pp. 1162-1171

Author(s):

Hongliu Ran

Keyword(s):

Seismic Hazard ◽

Hazard Assessment ◽

Seismic Hazard Assessment ◽

Source Zone ◽

Occurrence Rate ◽

Probabilistic Seismic Hazard Assessment ◽

Probabilistic Seismic Hazard ◽

Ground Acceleration ◽

Magnitude Distribution ◽

Aleatory Variability

ABSTRACT Aleatory variability is the natural randomness in a process and can affect probabilistic seismic hazard assessment (PSHA). In this study, considering a simple case of a square areal source zone, I employ Monte Carlo methods to estimate aleatory uncertainties due to random variations in temporal, spatial, and magnitude distribution of seismicity within the zone for PSHA. The results show that (1) uncertainty from aleatory variability in PSHA is significant for areas with low-seismic activity, (2) the ratio of the 85th to 15th percentiles of peak ground acceleration (PGA) decreases as the occurrence rate increases, and (3) accounting for random variations in seismic parameters changes the estimated PGA by more than 10%. My analysis applies to the case in which there are fewer than 10 earthquakes over 50 yr, the site is located outside of the areal source, and b≥1.0. This situation should be considered in PSHA due to the cutoff effect of the magnitude lower limit. In addition, the sensitivity analysis shows that random variations in earthquake magnitude distribution are the largest contributor to aleatory uncertainty in most cases.

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Preliminary re-evaluation of probabilistic seismic hazard assessment in Chile: from Arica to Taitao Peninsula

Advances in Geosciences ◽

10.5194/adgeo-22-147-2009 ◽

2009 ◽

Vol 22 ◽

pp. 147-153 ◽

Cited By ~ 10

Author(s):

F. Leyton ◽

S. Ruiz ◽

S. A. Sepúlveda

Keyword(s):

Seismic Hazard ◽

Hazard Assessment ◽

Seismic Hazard Assessment ◽

Probabilistic Seismic Hazard Assessment ◽

Probabilistic Seismic Hazard ◽

Intraplate Earthquakes ◽

Ground Acceleration ◽

The Andes ◽

Available Information ◽

Large Earthquakes

Abstract. Chile is one of the most seismically active countries in the world; indeed, having witnessed very large earthquakes associated with high horizontal peak ground accelerations, the use of probabilistic hazard assessment is an important tool in any decision-making. In the present study, we review all the available information to improve the estimation of the probabilistic seismic hazard caused by two main sources: shallow interplate, thrust earthquakes and intermediate depth, intraplate earthquakes. Using previously defined seismic zones, we compute Gutenberg-Richter laws and, along with appropriate attenuation laws, revaluate the probabilistic seismic hazard assessments in Chile. We obtain expected horizontal peak ground acceleration with a 10% of probability of being exceeded in 50 years, reaching from 0.6 g up 1.0 g in the coast and between 0.4 g and 0.6 g towards the Andes Mountains, with larger values in Northern part of the country. The present study improves our knowledge of geological hazards in Chile, enabling the mitigation of important human and material losses due to large earthquakes in the future.

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Probabilistic seismic hazard assessment of the Canterbury region, New Zealand

Bulletin of the New Zealand Society for Earthquake Engineering ◽

10.5459/bnzsee.34.4.318-334 ◽

2001 ◽

Vol 34 (4) ◽

pp. 318-334 ◽

Cited By ~ 10

Author(s):

Mark Stirling ◽

Jarg Pettinga ◽

Kelvin Berryman ◽

Mark Yetton

Keyword(s):

New Zealand ◽

Seismic Hazard ◽

Hazard Assessment ◽

Regional Scale ◽

Active Faults ◽

Seismic Hazard Assessment ◽

Historical Seismicity ◽

Probabilistic Seismic Hazard Assessment ◽

Probabilistic Seismic Hazard ◽

Ground Acceleration

We present the main results of a probabilistic seismic hazard assessment of the Canterbury region recently completed for Environment Canterbury (formerly Canterbury Regional Council). We use the distribution of active faults and the historical record of earthquakes to estimate the levels of earthquake shaking (peak ground acceleration and response spectral accelerations) that can be expected across the Canterbury region with return periods of 150, 475 and 1000 years. The strongest shaking (e.g. 475 year peak ground accelerations of 0.7g or more) can be expected in the west and north to northwest of the Canterbury region, where the greatest concentrations of known active faults and historical seismicity are located. Site-specific analyses of eight towns and cities selected by Environment Canterbury show that Arthur's Pass and Kaikoura are located within these zones of high hazard. In contrast, the centres studied in the Canterbury Plains (Rangiora, Kaiapoi, Christchurch, Ashburton, Temuka and Timaru) are generally located away from the zones of highest hazard. The study represents the first application of recently-developed methods in probabilistic seismic hazard at a regional scale in New Zealand.

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