On 11th of August 2012 the region was surprisingly struck by a shallow Mw 6.4 (USGS) earthquake with pure right-lateral strike-slip character only about 50 km north of the North-Tabriz FAULT. An east-west striking surface rupture of about 20 km length was observed in the field by Geological Survey of Iran. Only 11 minutes later and about 6 km further NW a second shallow event with Mw 6.2 occurred. It showed an NE-SW oriented oblique thrust mechanism (HRVD). This earthquake sequence provides an opportunity to better understand the processes of active deformation and their causes in NW-Iran.In recent years, seismologists have attempted to develop quantitative models of the earthquake rupture process with the ultimate goal of predicting strong ground motion. The choice of ground-motion model has a significant impact on hazard estimates for an active seismic zone such as the NW-Iran. Simulation procedures provide a means of including specific information about the earthquake source, the wave propagation path between the source and the site and local site response in an estimation of ground motion. Simulation procedures also provide a means of estimating the dependence of strong ground motions on variations in specific FAULT parameters. Several different methods for simulating strong ground motions are available in the literature. A number of possible methods that could be used to generate synthetic records include (i) deterministic methods, (ii) stochastic methods, (iii) empirical Green’s function, (iv) semi-empirical methods, (v) composite source models, and (vi) hybrid methods. The stochastic method begins with the specification of the Fourier spectrum of ground motion as a function of magnitude and distance. The acceleration spectrum is modeled by a spectrum with a ω2 shape, where w = angular frequency (Aki, 1967, Brune, 1970, Boore 1983). Finite FAULT modeling has been an important tool for the prediction of ground motion near the epicenters of large earthquakes (Hartzel, 1978, Irikura, 1983, Joyner and Boore, 1986, Heaton and Hartzel, 1986, Somerville et al., 1991, Tumarkin and Archuleta, 1994, Zeng et al. 1994, Beresnev and Atkinson, 1998). One of the most useful methods to simulate ground motion for a large earthquake is based on the simulation of a number of small earthquakes as subFAULTs that comprise a big FAULT. A large FAULT is divided into N subFAULTs and each subFAULT is considered as a small point source (introduced by Hartzel, 1978). The ground motions contributed by each subFAULT can be calculated by the stochastic point-source method and then summed at the observation point, with a proper time delay, to obtain the ground motion from the entire FAULT. We used the dynamic corner frequency approach. In this model, the corner frequency is a function of time, and the rupture history controls the frequency content of the simulated time series of each subFAULT. In this study, we identify the source parameters of the first earthquake August 11, 2012 Ahar-VARZAGHAN earthquake using stochastic finite FAULT method (Motazedian and Atkinson, 2005). We estimated the causative rupture length and the downdip causative rupture width using the empirical relations of Wells and Coppersmith (1994), from the best defined aftershocks zone and depth distribution of these aftershocks as 15km and 10km, respectively. The simulated results compared with recorded ones on both frequency and time domain. The good agreement between the simulations and records, at both low and high frequencies, gives us confidence in our simulation model parameters for NW-Iran. The estimated strike and dip of the causative FAULT are 85º and 83º. The FAULT plane was divided into 5×5 elements. Rupture was propagated at (i,j)= (4×3) element from east to west. The focal depth is approximately 12 km. We then obtained a spectral decay parameter (k) from the slope of smoothed amplitude of the Fourier spectra of acceleration at higher frequencies. The best fit coefficient for the horizontal component is k=0.0002R+0.047.The kappa factor for the vertical component is estimated based on the same procedure and estimated k=0.0002R+0.034. These equations represent the k0 for horizontal component is larger than that of the vertical component. This confirms that the attenuation of higher frequencies is much less on the vertical than the horizontal component, as the vertical component is less sensitive to the variation of shear-wave velocity of near-surface deposits. The clear difference between vertical and horizontal values suggests that k0 contains dependence on near surface site specific attenuation effects. In the absence of three-component stations, values obtained from vertical components may be helpful for a first estimate of this parameter. We also calculated residuals for each record at each frequency, where the residual is defined as log (observed PSA) - log (predicted PSA), where PSA is the horizontal component of 5% damped pseudo acceleration. We sorted simulated records according to agreement between Fourier spectrum and response spectra into two groups, A and B. The simulation using A quality agrees betther with observed records than that using B quality. The lowest residuals averaged over all frequencies are from 0.4 to 18.3 Hz for A quality and from 1.2 to 18 Hz for B quality simulated.

Full Text [PDF 1187KB] The region of northwestern Iran is exceptional within the Arabian-Eurasian continental collision zone. The tectonics is dominated by the NW-SE striking right-lateral North Tabriz FAULT (NTF) and regional seismicity (historical and modern one) concentrates. The NTF is a major seismogenic FAULT in NW Iran. The last damaging earthquakes on this FAULT occurred in 1721, rupturing the southeastern FAULT segment, and in 1780, rupturing the northwestern one. The understanding of the seismic behavior of this FAULT is critical for assessing the hazard in Tabriz, one of the major cities of Iran; the city suffered major damage in both the 1721 and 1780 events. The north of the NTF seismicity is rare, and almost nothing has been revealed about activity of the structures until now.On 11th of August 2012, the region was surprisingly struck by a shallow Mw 6.5 earthquake with a pure right-lateral strike-slip character only about 50 km to the north of the NTF. An east-west striking surface rupture of about 20 km length was observed in the field by Geological Survey of Iran. Only 11 minutes later and about 6 km further to NW, a second shallow event with Mw 6.2 occurred. It showed an NE-SW oriented oblique thrust mechanism. This earthquake sequence provided an opportunity to understand better the processes of active deformations and their causes in NW Iran.Ground-motion relations describing the expected amplitudes of this motion as functions of the magnitude and distance are key components of seismic hazard analyses. Ground-motion (attenuation) relations are used to estimate strong ground motion for many engineering and seismological applications. Where strong motion recordings are abundant, these relations are developed empirically from strong-motion recordings. Where recordings are limited, they are often developed from seismological models using stochastic and theoretical methods.The stochastic model is a widely-used tool to simulate acceleration time series and develop ground motion relations (Hanks and McGuire, 1981; Boore, 1983; Boore and Atkinson, 1987; Atkinson and Boore, 1995 and 1997; Atkinson and Silva, 1997 and 2000). The stochastic method begins with the specification of the Fourier spectrum of the ground motion as a function of magnitude and distance. The acceleration spectrum is modeled by a spectrum with ω2 shape, where ω is the angular frequency (Aki, 1967; Brune, 1970; Boore 1983). Finite FAULT modeling has been an important tool for the prediction of ground motion near the epicenters of large earthquakes (Hartzel, 1978; Irikura, 1983; Joyner and Boore, 1986; Heaton and Hartzel, 1986; Somerville et al., 1991; Tumarkin and Archuleta, 1994; Zeng et al., 1994; Beresnev and Atkinson, 1998a). One of the most useful methods to simulate ground motion for a large earthquake is based on the simulation of some small earthquakes as subFAULTs that comprise a big FAULT. A large FAULT is divided into N subFAULTs, and each subFAULT is considered as a small point source (introduced by Hartzel, 1978).In this study, the first region-specific ground motion relations were developed for seismic hazard analysis of NW Iran. The attenuation relation for the horizontal acceleration response spectrum in a period of 0-4 s, with a magnitude range of Mw=5 to 7.7 and distances up to 150 km were established. We used 51 waveforms recorded on a rock site in the NW Iran. Due to the paucity of the data at small distances and large magnitudes, we applied the stochastic method to simulate waveforms for different magnitudes and distances. To overcome the incompleteness of the data set, we simulated 1240 acceleration time series for magnitudes from M5.0 to M7.7 and magnitude steps of 0.2 units for the North Tabriz FAULT and M5.0 to 6.7 and magnitude steps of 0.5 units for the Ahar FAULT. The relations were derived by a maximum likelihood regression algorithm from Joyner and Boore (1993) on a set of 1240 simulated strong-motion records and 51 observed ground motions recorded on the rock site in this region. The theoretical-empirical ground motion relation for NW Iran was compared to the ground motion relations for the other regions and had a good agreement with them especially with Akkar and Bommer relations for Europe, the Mediterranean Region and the Middle East. The present results will be useful in estimating strong ground motion parameters and in the earthquake resistant designs in this region.

Seismic values are the main parameters in evaluating the neotectonic activity of a region. In August 11, 2011, two Mb=6.4 and Mb=6.3 earthquakes occurred in Ahar-VARZAGHAN region within 11 minutes. Seismotectonic investigations imply that the FAULTs generating the events are the young FAULTs of the regions. Also, distribution of the epicenters represent a pattern consistent with the FAULT trends in the area. Temporal and spatial distribution of the earthquakes (fractal analysis) as earthquake pre-indicators together with a-b values were used to assess the neotectonic activity and explore the seismic model of the Ahar area. Results show a sharp decrease in b-value, indicating that the main shock was associated with a zone of high strain rate. The seismic model presented for the Ahar area illustrates three periods after the main shock including: 1) an early quiescence Q1, 2) an aftershock period B, and 3) a late quiescence Q2. The rather increase in b-value during the Q2 period is interpreted to indicate stress decrease in the region.

114 three-component strong motion records from 2012 Ahar-VARZAGHAN double earthquakes (Mw=6.5, 6.3) are used to study the apparent source spectra of these two events. For this purpose, all the known effects of local site and travel path were deconvolved from the observed spectra. As of path effects (attenuation model), two models are considered: 1) a model developed by the authors in an earlier study with the geometrical spreading form of R-0.9 at close distances, 2) a model developed in this study in which the geometrical spreading has the more conventional form of R-1 at close distances. These two models have very similar associated Q factors, as the Q factor is more affected by the rate of geometrical spreading at longer distances. It is observed that the inferred source spectrum (particularly Brune stress drop) depends strongly on the considered attenuation model. For the studied events, the apparent observed source spectra for vertical and horizontal components show overall similarity, with horizontal component having bigger scatter and higher fluctuations. The apparent source spectrum of the first event almost perfectly matches the well-known Brune model; whereas the second event is a fair match to the Brune model and is better represented by a double corner frequency model. Out of four double-corner frequency models of source spectra where evaluated here, only the recently developed generalized double-corner-frequency model can successfully reproduce the observed ground motions; the other three lack flexibility in matching the high-frequency spectral level.

Hajilerchai region is located in Varzeqan city of East Azerbaijan province, Iran. Archaeological surveys of the area were conducted to clarify the settlement landscape of the area. A total of thirty sites were identified in the area. There are two bronze age sites identified by means of an archaeological surface survey in the region. Hajilarchai area of Varzeqan is one of the lesserknown parts, about which archeological research has not been done so far. This study was first conducted by field research. Then, using the GIS maps, the exact landscape of the area was determined, and the settlement patterns were explained. In this study, in addition to general characteristics and pathology, each site was introduced separately, presenting the area's settlement pattern. With a descriptive-analytical approach, this research tried to answer how the settlement patterns have changed in different historical periods. With the beginning of the historical and Islamic period, especially the Parthian period, the region has enjoyed certain prosperity and development. This study showed that most of the ancient sites along the Hajilerchai River are located at the tributaries of the Aras River, and environmental conditions and proximity to the river have played an essential role in establishing settlements.

This study is an attempt to investigate human and physical factors effecting zoning of Markazi District in VARZAGHAN Country. To do so, this study employed the precise technique of GIS to produce and analyze maps. In this process initially settlements were examined from four points of view including topography, slop, capability of land, and availability of water resources, then, related maps were created. After that, By utilizing weight center index model, rural settlement were ranked regarding human factors, population, availability of roads, health service, education service and infrastructural facility. After this stage, applying neighborhood interpolation analysis IDW (inverse distance weighted) model the all district were divided into different zones. Then, standardization blending of layers and were conducted using overlaying and map blending such as Boolean logic and weighting with ranking system. Finally, with overlaying the created maps with physical and human resources utilizing the said models the appropriate districts for the establishment of rural service centers were located. 

In this paper we have presented a new design of FAULT tolerant comparator with a FAULT free hot spare. The aim of this design is to achieve a low overhead of time and area in FAULT tolerant comparators. We have used hot standby technique to normal operation of the system without interrupting and dynamic recovery method in FAULT detection and correction. The circuit is divided to smaller modules for ease of testing and one hot spare is used for reconfiguration. Complexity, time and area overhead of designed FAULT tolerant comparator are more effective in compared recent methods.

Objectives: Although the earthquake is a natural disaster, it has become a social subject and has created vulnerable groups due to its various social effects. One of these groups is the elderly. The present study aimed to investigate the social vulnerability of elderly people who experienced earthquakes.Methods & Materials: The present study involved a cross-sectional qualitative-quantitative method. The population comprised all the elderly people in Kerman and East Azarbaijan provinces. In the qualitative part, in order to identify the social problem of elderly who experienced an earthquake, Categories has been collected By focus group. For this purpose, 17 people were selected by purposive sampling method for focus group of elderly and the social damage of the earthquake was determined. In the quantitative phase, 90 older people who have experienced the earthquake in Bam, VARZAGHAN and Ahar were selected randomly, and 90 older people who have not experienced an earthquake were selected and matched with the first group. Both groups answered the questionnaire on social isolation, social support, social adjustment questionnaire, and Marlowe-Crowne Social Desirability Scale. The collected data were analyzed by SPSS software (version 21) and t-test.Results: In the qualitative part, social damage of earthquakes, including social incompatibility, social isolation, lack of social acceptance and lack of social support were identified through interviews. In the quantitative results, the average of social incompatibility was 4.93±0.66, social isolation was 12.23±3.91, social acceptance was 11.41±2.38, and social support was 34.12±6.81 among the older people who faced an earthquake. However, the average of social conflict was 3.42±1.16, social isolation was 8.06±3.17, social acceptance was 24.7±4.66, and social support was 68.9±8.96 among the other older people. The findings of the study showed that the rate of social compatibility of the older people who have experienced the earthquake is less than that of other older people, but the social isolation is more than that in other older people (P<0.01). The results showed that feelings of social support and acceptance of older people who have experienced the earthquake were less than that of other older people (P<0.01).Conclusion: Based on the results of the study, it was concluded that older people is one of Social groups that in the earthquake addition of distraction and loss of orientation and memory, confront with social problems that have not been considered. So, planning and preparing strategies to reduce and control such injuries are important.

In this paper, a new open-switch FAULT diagnosis method is proposed for the six-phase AC-DC converter based on the difference between the phase current and the corresponding reference using an adaptive threshold. The open-switch FAULTs are detected without any additional equipment and complicated calculations, since the proposed FAULT detection method is integrated with the controller required signals. The proposed FAULT-tolerant technique reduces the value of overcurrent and total harmonic distortion (THD) on the healthy and FAULTy phases, by considering the redundancy mode of space vectors in space vector pulse width modulation (SVPWM) and changing the switching signals in FAULT regions. This technique is performed without adding any legs, switches or triode for alternating currents (TRIAC) to the circuit. Finally, the proposed FAULT-tolerant technique is evaluated by MATLAB simulation and the results show its effectiveness.