Using 48016 synthetic maximum Wood-Anderson amplitudes read from waveforms of 2650 events recorded by stations of Iranian Seismological Center (IRSC, irsc. ut. ac. ir), Iranian National Seismograph Network (INSN, www. iiees. ac. ir) and temporary seismic networks belong to Institute for Advanced Studies in Basic Sciences (IASBS, iasbs. ac. ir), the empirical attenuation curve ( 0  log A ) for Local Magnitude of Iran has been calculated as follows: 0 log (1. 556 0. 06) log (0. 001637 0. 0009) ( 100) 3 100 R A R              where R is hypocentral distance in km and 0 A is maximum displacement amplitude of shear wave in millimeter. The empirical attenuation relationship is valid for hypocentral distances equal or smaller than 800 km. ML amplitude is the maximum amplitude observed on a Wood-Anderson (W-A) seismogram. We manually picked the maximum amplitudes on the shear window of synthetic W-A seismograms having S/N of larger than 5. We calculated synthetic W-A seismograms by removing the instrument response of each record and convolving the resulting signal with the response of the standard W-A torsion seismograph. We assumed a static magnification of 2080 for the W-A instrument. The selected ML amplitudes are belonging to events at hypocentral distance of 10 to 800 km. Except for the Makran and South Caspian Basin regions, the ray coverage of the ML amplitude covers properly the whole Iranian Plateau. To reduce the scatter of Magnitude residues and ensure a reliable calculation of the attenuation curve, the selected events belong to 45 precisely relocated seismic clusters with location uncertainties of 5 km or less. The cluster approach produces redundancy in amplitudes arriving from a cluster to a given station. The redundancy will facilitate easy recognition and removal of possible outliers and thus provide a reliable estimate for the Magnitude station correction. The Magnitude station corrections attempts to absorb the regional attenuation difference relative to that dictated by average attenuation relationship derived in this work. The calculated attenuation curve shows a larger geometrical spreading for hypocentral distances closer than 100 km, representing a super-spherical geometrical spreading, and a smaller value for intrinsic attenuation for distances farther than 200 km once compared with the currently used ML relationship of Hutton and Boore (1987). Excluding amplitudes with hypocentral distances smaller than 60 km results in a geometrical spreading coefficient close to spherical spreading, emphasizing the importance of near distances data on accurate estimation of the geometrical spreading value. The difference in the attenuation parameters between our results and those of Hutton and Boore (1987) relationship clearly indicates the crustal disparity of Iranian Plateau and southern California. This necessitates using the new attenuation relationship for Iran. We calculated the Local Magnitude empirical attenuation relationship by inverting the amplitude data set for the geometrical spreadin]g and intrinsic attenuation. We did not consider Magnitude station corrections in our inversion to avoid any tradeoff between the station corrections and attenuation parameters. We have shown that the Magnitude residuals calculated by our Local Magnitude empirical relationship do not vary systemically versus hypocentral distance or Magnitude. Due to the cluster-wise approach in selection of our events and partially because of the precise location of the selected events, the standard deviation of Magnitude residues is about 0. 19, significantly smaller than those reported by others. We calculated the station corrections by averaging the Magnitude residual in each station. The station corrections vary between-0. 44 to 0. 32. Generally, stations located in Zagros, Alborz and north west of Iran have negative station correction representing amplitude amplification in these regions relative to central Iran and north east of Iran. The new attenuation relationship provides better estimates for the attenuation parameters and especially provides precise Magnitudes at close hypocentral distances. By time, the expansion of Iranian seismic networks reduces the average distance spacing of Iranian seismic stations and thus usage of better Local Magnitude formula such as ours becomes more important.

The availability of a large amount of the data recorded by the Iranian Seismic Telemetry Network (ISTN) has motivated this study to develop relations for the routine determination of ML scale for Central Alborz region of northern Iran. The ML is commonly used in engineering because it is determined within the frequency range (0.5-3 sec) of interest in most of such applications. For any comprehensive seismic hazard analysis, one needs a calibrated Magnitude relationship as well as an earthquake catalog for the study region. It is a well-known fact that the regional geology has a great influence on Magnitude relations. Therefore, for each seismic region a specific Magnitude relation has to be developed. The ML scale is based on the arithmetic mean of horizontal components of the synthesized Wood–Anderson seismograms. We used both nonparametric and parametric methods for inversion. We used a large dataset of 3886 events including 62031 waveforms which recorded by Tehran, Semnan and Sari seismic networks during 02/03/1997 to 13/03/2011. These seismic networks comprise of 19 three-component stations. We calculated the associated synthesized Wood-Anderson seismogram for each SS-1 waveform which records the velocity. Based on Richter’s method, we used amplitudes which are arithmetic means of those of horizontal components.Richter’s ML formula first developed for southern California and Savage and Anderson introduced a nonparametric least-squares inversion method which has been used by others. In this method, the amplitudes recorded at arbitrary distances are linearly interpolated to yield values for the attenuation curve at some fixed distances. In this study, we used both methods.The resulting equations are -logA0=0.9819log (r/100)+0.0028 (r-100)+3.0 and-logA0=1.076log (r)+0.0029 (r)+0.5580 from parametric and non-parametric methods, respectively. Where r is hypocentral in kilometer and A0 is amplitude in millimeter. The two methods yielded very similar results. Unlike the parametric method, the nonparametric one does not impose any a priori assumption of the shape of the attenuation curve on the data and has the potential to detect hinges in the attenuation curve that are caused by structural boundaries such as Moho or geological variations affects on the attenuation curve. Thus the result obtained by nonparametric method was chosen as the final result.Bakun and Joyner (1984) give the following formula for the Q/f ratio: taking an average S-wave crustal velocity of VS=3.3 km/sec, the k value obtained by the non-parametric method, 0.0029, would imply a Q/f ratio of 150 in Central Alborz, Iran.

Due to absence of an appropriate scale for estimation of ML for the earthquakes in eastern Alborz Range, we calculated 1113 synthetic Wood-Anderson peak amplitudes from waveforms of 215 earthquakes recorded by 23 stations at Local hypocentral distances. The events were recorded by two Local temporary seismological networks installed during 2007 and 2008 by the Geological Survey of Iran (GSI) and the stations of the permanent network of the Institute of Geophysics of University of Tehran (IGUT). Both temporary networks were installed for ML two discontinuous periods of nine months in the eastern- middle Alborz. In order to estimate an empirical attenuation curve for ML amplitudes, A, read from the stations at very short hypocentral distances, we fit a parametric relationship to the peak amplitude readings while considering geometrical spreading, intrinsic attenuation and stations corrections. We obtained the following empirical attenuation relationship:log Aij =1.986 log [rij/100]-0.00452 (Rij-100) -3+SjWhere R  is hypocentral distance in km between the jth station pair and ith earthquake and Sj is value of station correction for the jth station The realtionship clearly indicates a larger attenuation for shear waves in short hypocentral distances below 20 km. Our new ML relationship implies ML that using ML relationship derived for hypocentral distances larger than 50 km would overestimate ML Magnitude of events recorded by our Local networks by about half of unit Magnitude. Thus we suggest that for Local networks in other regions lacking any Local ML relationship, ML relationship derived in this study to be used.

In this study, by using number of events contain explosions and natural earthquakes which were discriminated before, we tried to compare Mw/ML relationship between explosions and earthquakes. The data bank which used in this study contains 30 explosions and 69 earthquakes which happened in Tehran region (Long. 50o-55o and Lat. 35o-37o) between 2006 and 2009 and recorded by Iranian Seismic Telemetry Network (ISTN). All of these events are Local and the range of their Magnitudes are 1<ML<4. By calculating Local and moment Magnitudes we found that Mw/ML relationship is MW=0.765ML+1.099 for explosions and MW=0.681ML+1.369 for earthquakes. This comparison was done again on a smaller Magnitude range of 1.1<ML<2.1 where the equation changed for earthquakes with MW=0.508ML+1.715, and in case of explosions, since all events were smaller than 2.1 (ML scale), the equation did not change.

Let R be a commutative Noetherian ring, a be an ideal of R, and D(R) denote the derived category of R-modules. For any homologically-bounded complex X, we conjecture that supL a(X)  magRX. We prove this in several cases.

Magnitude has played a particular role in the realistic description of global seismicity. Most studies in earthquake seismology use Magnitude data as a guide to the strength of an earthquake. So biases in Magnitude estimates, caused by any effect, directly affect the result of any study in which Magnitude data is used. In this study, efficiency of using different formulae and depth-distance calibration terms are examined. Applications of the MsR-P formula and new depth-distance terms to the ISC dataset, show that the estimated Ms and mb values are independent of distance, and provide unbiased estimates of Ms and mb in comparison with commonly-used Prague formula and Gutenberg-Richter terms. Comparison of standard deviation of Ms values for single events using the MsR-P and MsPrague formulae show that the MsR-P standard deviations are consistently smaller than those of Prague formula. Also standard deviations of estimated mb values using the new depth-distance terms are smaller than standard deviations of estimated values using Gutenberg-Richter terms. Estimated Ms and mb values using MsR-P formula and the new depth-distance terms reduce overlap in Ms:mb criterion for underground explosions and earthquakes. The study reported here confirms the need to modify the formula for Ms calculation and depth-distance correction terms for mb calculation, which are used by global agencies such as ISC and NEIC.

The central issue of the present paper is the study of the causes of the mother tongue decline in the Sahne city in Kermanshah province. The issue of language is beyond the dialect of people and is refer to the form of life and the matter of macroeconomic and political relations. From this perspective, the form of life and the language associated with it explain the praxis of the members of the society. The appropriate method of examining the problem should be able to analyze the justification of agents to their situation, that is why Grounded Theory is chosen as the method of this research and data analysis is taken from abduction reasoning. The results of the analysis introduced the categories of globalizing, modernizing, de-use of language, economic necessity and the government as the most important factors of Local language fading. In this essay the meaning of globalization is the globalizing of special type of economic relation that explain other categories role in the process of fading of languages.