scholarly journals MODELING OF SUBSURFACE FAULT FOR STRONG MOTION PREDICTION INFERRED FROM SHORT ACTIVE FAULT OBSERVED ON GROUND SURFACE

2010 ◽  
Vol 75 (648) ◽  
pp. 279-288 ◽  
Author(s):  
Kazuo DAN ◽  
Dianshu JU ◽  
Manami MUTO
Keyword(s):  
Active Fault ◽  
Ground Surface ◽  
Strong Motion ◽  
Motion Prediction

The Kozani-Grevena (Greece) earthquake of 13 May 1995 revisited from a detailed seismological study

1997 ◽  
Vol 87 (2) ◽  
pp. 463-473
Author(s):  
D. Hatzfeld ◽  
V. Karakostas ◽  
M. Ziazia ◽  
G. Selvaggi ◽  
S. Leborgne ◽  
...  
Keyword(s):  
Seismic Activity ◽  
Active Fault ◽  
Fault Plane ◽  
Ground Surface ◽  
Strong Motion ◽  
Normal Fault ◽  
Normal Faulting ◽  
Waveform Modeling ◽  
Epicentral Region ◽  
Better Than

Abstract The Kozani earthquake (Ms = 6.6) of 13 May 1995 is the strongest event of the decade in Greece and occurred in a region of low seismic activity. Using regional data and the strong-motion record at the Kozani station, we relocate the mainshock at 40.183° N and 21.660° E, beneath the Vourinos massif at a depth of 14.2 km. We also compute a focal mechanism by body-waveform modeling at teleseismic distance, which confirms a normal mechanism. The most likely plane strikes 240° ± 1° N and dips 40° ± 1° N with a centroid depth of 11 ± 1 km. Modeling of the strong-motion record at Kozani confirms that nucleation started at the eastern termination of the bottom of the fault. Six days after the mainshock, we installed a network of 40 portable seismological stations for one week around the epicentral region. Several thousand aftershocks were recorded, among which we locate 622 with a precision better than 1 km. We compute 181 focal mechanisms that mostly show normal faulting. The aftershock seismicity is restricted between 5 and 15 km depth and defines a plane dipping north at an angle of about 35°, consistent with the mainshock mechanism. Seismic activity with the same pattern of normal fault mechanisms is also seen on an antithetic fault connected to the main one at 12 km depth, which cuts the ground surface north of the Vourinos ophiolite massif in the Siatista valley. These results suggest two possibilities for the active fault plane; either it is the Deskati fault that is flat and dips with a constant angle, and therefore the surface breaks are secondary features, or, more likely, it is the Paleohori fault that is new, of listric shape, and located ahead of the Deskati fault, which was not active during the earthquake.

Ground-motion model for subduction earthquakes in northern South America

2021 ◽  
pp. 875529302110275
Author(s):  
Carlos A Arteta ◽  
Cesar A Pajaro ◽  
Vicente Mercado ◽  
Julián Montejo ◽  
Mónica Arcila ◽  
...  
Keyword(s):  
South America ◽  
Ground Motion ◽  
Ground Motions ◽  
Strong Motion ◽  
Motion Prediction ◽  
Depth Range ◽  
Ground Motion Prediction ◽  
Natural Period ◽  
Nazca Plate ◽  
Northern South America

Subduction ground motions in northern South America are about a factor of 2 smaller than the ground motions for similar events in other regions. Nevertheless, historical and recent large-interface and intermediate-depth slab earthquakes of moment magnitudes Mw = 7.8 (Ecuador, 2016) and 7.2 (Colombia, 2012) evidenced the vast potential damage that vulnerable populations close to earthquake epicenters could experience. This article proposes a new empirical ground-motion prediction model for subduction events in northern South America, a regionalization of the global AG2020 ground-motion prediction equations. An updated ground-motion database curated by the Colombian Geological Survey is employed. It comprises recordings from earthquakes associated with the subduction of the Nazca plate gathered by the National Strong Motion Network in Colombia and by the Institute of Geophysics at Escuela Politécnica Nacional in Ecuador. The regional terms of our model are estimated with 539 records from 60 subduction events in Colombia and Ecuador with epicenters in the range of −0.6° to 7.6°N and 75.5° to 79.6°W, with Mw≥4.5, hypocentral depth range of 4 ≤  Zhypo ≤ 210 km, for distances up to 350 km. The model includes forearc and backarc terms to account for larger attenuation at backarc sites for slab events and site categorization based on natural period. The proposed model corrects the median AG2020 global model to better account for the larger attenuation of local ground motions and includes a partially non-ergodic variance model.

Preliminary microzonation of the Memphis, Tennessee, area

1982 ◽  
Vol 72 (3) ◽  
pp. 1011-1024
Author(s):  
Sunil Sharma ◽  
William D. Kovacs
Keyword(s):  
United States ◽  
Soil Properties ◽  
Damping Ratio ◽  
Ground Surface ◽  
Strong Motion ◽  
Response Analysis ◽  
Borehole Data ◽  
Central United States ◽  
Hazardous Zone ◽  
High Level

abstract The city of Memphis, which is situated very close to the inferred epicenter of one of the three major 1811 to 1812 earthquakes, is in a potentially hazardous zone which will be susceptible to the usual seismic hazards. By recognizing the high level of seismicity in the New Madrid area, this study attempts to microzone the potential hazards by considering the following subjects: (i) the seismicity of the central United States; (ii) design earthquakes; and (iii) response analysis which allows construction of the necessary microzonation maps. The seismicity of the region is evaluated from state-of-the-art literature as there is no recorded strong-motion data available for the central United States. Synthetically generated accelerograms, simulating the design earthquakes, were used to represent the ground motions which were applied at a depth of 45 m, below ground surface, at numerous sites in Memphis. The soil stratigraphy was conceptualized from borehole data, made available by local sources, and dynamic soil properties estimated from available empirical correlations. The results of the response analysis were transformed into microzonation maps depicting: (i) zones showing qualitative estimates of ground response; (ii) zones showing the natural frequency of the soils; (iii) zones showing the peak spectral acceleration for 2 per cent damping ratio; and (iv) zones of liquefaction potential. These maps are useful for preliminary design and are not intended to be used on a quantitative basis. Further investigation is necessary in determining the stratigraphy and soil properties for a site-specific design and analysis.

A Comparison of Ground Motion Prediction Equations for Arias Intensity and Cumulative Absolute Velocity Developed Using a Consistent Database and Functional Form

2012 ◽  
Vol 28 (3) ◽  
pp. 931-941 ◽  
Author(s):  
Kenneth W. Campbell ◽  
Yousef Bozorgnia
Keyword(s):  
Ground Motion ◽  
Functional Form ◽  
Strong Motion ◽  
Prediction Equation ◽  
Absolute Velocity ◽  
Motion Prediction ◽  
Ground Motion Prediction ◽  
Arias Intensity ◽  
Intensity Measures ◽  
Cumulative Absolute Velocity

Arias intensity (AI) and cumulative absolute velocity (CAV) have been proposed as instrumental intensity measures that can incorporate the cumulative effects of ground motion duration and intensity on the response of structural and geotechnical systems. In this study, we have developed a ground motion prediction equation (GMPE) for the horizontal component of AI in order to compare its predictability to a similar GMPE for CAV. Both GMPEs were developed using the same strong motion database and functional form in order to eliminate any bias these factors might cause in the comparison. This comparison shows that AI exhibits significantly greater amplitude scaling and aleatory uncertainty than CAV. The smaller standard deviation and less sensitivity to amplitude suggests that CAV is more predictable than AI and should be considered as an alternative to AI in engineering and geotechnical applications where the latter intensity measure is traditionally used.

scholarly journals EVALUATION OF DIFFICULT AREA FOR TSUNAMI EVACUATION IN HIROKAWA TOWN, WAKAYAMA PREFECTURE, JAPAN, BASED ON STRONG MOTION PREDICTION AND WALKING EXPERIMENT

2016 ◽  
Vol 72 (2) ◽  
pp. I_503-I_508
Author(s):  
Yoshiya HATA ◽  
Fumihiro MINATO ◽  
Maki KOYAMA ◽  
Yasuko KUWATA ◽  
Tadayoshi NAKASHIMA ◽  
...  
Keyword(s):  
Strong Motion ◽  
Motion Prediction ◽  
Difficult Area

scholarly journals A Procedure to Select Earthquake Time Histories for Deterministic Seismic Hazard Analysis: Case Studies of Major Cities in Taiwan

2017 ◽  
Author(s):  
Duruo Huang ◽  
Wenqi Du
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Ground Surface ◽  
Strong Motion ◽  
Response Spectra ◽  
Dynamic Responses ◽  
Motion Time ◽  
Acceleration Time Histories ◽  
Time Histories ◽  
Deterministic Seismic Hazard

Abstract. In performance-based seismic design, ground-motion time histories are needed for analyzing dynamic responses of nonlinear structural systems. However, the number of strong-motion data at design level is often limited. In order to analyze seismic performance of structures, ground-motion time histories need to be either selected from recorded strong-motion database, or numerically simulated using stochastic approaches. In this paper, a detailed procedure to select proper acceleration time histories from the Next Generation Attenuation (NGA) database for several cities in Taiwan is presented. Target response spectra are initially determined based on a local ground motion prediction equation under representative deterministic seismic hazard analyses. Then several suites of ground motions are selected for these cities using the Design Ground Motion Library (DGML), a recently proposed interactive ground-motion selection tool. The selected time histories are representatives of the regional seismic hazard, and should be beneficial to earthquake studies when comprehensive seismic hazard assessments and site investigations are yet available. Note that this method is also applicable to site-specific motion selections with the target spectra near the ground surface considering the site effect.

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