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. 

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.

The Ahar-VARZAGHAN double earthquakes happened in August 11, 2012 in north-west of Iran. There were two main tremors, the first with 6. 2 happened only eleven minutes before the second one with 6. 3 in the Richter scale. More than 300 people lost their lives and 3000 were injured. Although there is no way to prevent the negative consequences of an earthquake at the moment, reducing the impact of the damages is possible through disaster management. In reverse, it has been proved that in the absence of disaster management, which basically also rooted in inaccurate dissemination of information, the damage can increase and result in secondary environmental effects such as social disorders, objections and chaos. In this regard, dissemination of information during disasters and broadcasting accurate, thorough and transparent news about an earthquake and its impact in the first hours after an event has a crucial role in the process of disaster management and preventing its disastrous consequences. In this paper, the information has been gathered through library research as well as interviews with responsible officials after the twin Ahar-VARZAGHAN earthquakes. The new coverage, especially by Islamic Republic of Iran Broadcasting (IRIB), as the national and official media, is evaluated. In this regard, two main factors have been considered, that is “ information about the earthquake and its characteristics” and “ dissemination of information about the effects of an earthquake” . The results show that quick and on time information dissemination regarding the effects of Ahar-VARZAGHAN earthquakes have been weak and reveals that a quick system for estimating the casualties and damages need to be reinforced. It also shows that media specially broadcasting media has not paid much attention to the accuracy of the disseminated news. The broadcasting of news is immediate, but its accuracy is under question. Also, with regard to the experience of twin Ahar-VARZAGHAN earthquakes and comparing the process of information dissemination between national and local networks, the latter showed a quicker and more effective performance than the national networks.

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.

North-western Iran (Azerbaijan province), one of the most seismic regions of the country, has experienced many seismic events during its long history. The recent dual earthquake with Mw = 6:4 and Mw = 6:3 struck the Ahar-VARZAGHAN area in Azerbaijan province in 2012.8.11 and caused a lot of fatalities. In this paper, the varieties of several seismic parameters, such as the b-value of the Gutenberg-Richter relation and standard deviation, Z, have been investigated to explore the temporal and spatial changes of seismicity patterns. Calculating and comparing these data before and after the occurrence of earthquake demonstrate some information about anomaly preceding main shocks. Temporal variations of b-value show a clear decrease before the 2012 Ahar- VARZAGHAN dual earthquakes. Considering the spatial changes in the b-values, it is possible to recognize a zone with abnormal low b-values around the epicenter of these events. The variation of the b and Z-values around the epicenter shows preparedness of the region before the occurrence of the main shock of Ahar-VARZAGHAN earthquake.

VARZAGHAN district is located in NW of Arasbaran magmatic belt (AMB) which is one of the most highly mineralized region in Iran and host to a significant number of porphyry Cu deposits such as Sungun Cu-Mo porphyry deposit. The main goal of this study is synthesizing diverse raster-based evidence layers including geochemical, alteration and geological geo-data sets for mineral prospectivity modeling (MPM). For this purpose, firstly, continuous values of six favorable evidential maps as main criteria (geochemical signature of PC1 scores, values of proximity to argillic, phyllic and iron-oxide alterations, values of proximity to Oligo-Miocene intrusions and fault density) were divided into reasonable classes by applying concentration-area fractal model and then discretized layers were integrated using analytical hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS) to generate a final map of porphyry Cu potential within the central part of VARZAGHAN district. Finally, the success-rate curve of the AHP-TOPSIS model as a quantitative evaluation method according to the locations of known Cu occurrences was drawn. Results revealed the successful performance of AHP-TOPSIS model in portraying the prospective areas related to porphyry Cu mineralization.

Earthquake relocation has an important role in the investigation of tectonic settings of a region. An increase in accuracy of a relocation problem can enhance the calculation of the local velocity model as well as associated studies of a risk analysis. There are some important procedures to make a reliable catalog of earthquakes. Verifying the seismic waveform to correct the picked phases, utilizing other seismic networks and using an appropriate local or regional velocity model, we can improve the final results. In a case with a well-conditioned network geometry, using an accurate local velocity model has a significant effect on increasing the depth accuracy. In this study, we have tried to use all available information from seismic networks in NW Iran and south Azerbayjan. We relocated the double main-shock of VARZAGHAN-Ahar Mw 6.5, Mw 6.3 and more than 1800 aftershocks with Ml> 2.0 over a 10-month period after the main shocks. To increase the accuracy of the earthquake location, we merged the recorded information of eight short periods of the Iranian Seismological Center (IRSC), one broad band station of the International Institute of Engineering and Earthquake Seismology (IIEES) and five broad band stations of the Azerbaijan National Seismic Network (ANSN). We also calculated a local velocity model using a P arrival time inversion scheme (using VELEST code) not only to obtain a more reliable earthquake location especially in depth, but also to decrease the hypocentral error. We have used all the data between 2006 and 2013 after applying a band-pass filter to get a uniform dataset of the earthquake within 250 km around the main shocks. The final velocity model indicated two velocity layers in the upper-crust with p-velocities of 5.87, 6.01 km/s and 6, 18 km thicknesses, respectively. These layers lay on a half-space with a p-velocity of 6.40 km/s. To minimize the effect of the initial velocity model on the final result, we implemented 50 random depth-increasing velocity models. Furthermore, making use of a non-linear probabilistic approach for relocating the earthquake leads to more accurate results compared to linear location programs. A comparison of the results of hypocenters between the IRSC catalog and those calculated by this study shows better line-alignment in the direction of the infer fault. Epicenter and depth error reduction due to making use of an accurate local velocity model were clearly obvious. Plotting the five depth cross sections along and perpendicular to after-shock sequence, shows a more clear geometry compared to the fixed-depth results from the IRSC catalog. According to some statistical parameters such as the hypocentral error, RMS and also preliminary location conditions such as the azimuthal gap and the number of stations, we defined two classes of events and plotted them for both IRSC and this study in map view and cross sections. This was a better way to show accuracy of our dataset (relocated events) than what we obtained by IRSC. Using the focal mechanism of the two main shocks obtained by the IRSC, along with the event distribution especially in depth, showed that there was more consistency between the results of this study and the fault orientation. This showed that the infer fault had a near vertical plane with an east-west direction and this suggested that it would be a strike-slip fault.