iran earthquake

NW Iran-SE Turkey is a tectonically active zone related to the Arabia-Eurasia convergence, but the active stress state in this zone has not yet been clearly studied. To improve the knowledge of present-day stress state in this region, optimum reduced stress tensor was analysed. For this, a large number of earthquake focal mechanisms (277) were collected. The analyses show most mechanisms exhibit strike-slip to thrust faulting. These data indicate that this region is dominated by an N158° maximum horizontal compressive stress (SHmax) belonging to a transpressional tectonic regime.

21p tanmocphong 29-01-2022 29 1   Download

Medium to large b-values (0.74, 0.75, 0.76, 0.79 and 1.01) are accompanied with small to large strain rates (1.42×10 -9 , 2.09×10 -9 , 2.19×10 -9 , 4.15×10 -9 and 1.24×10 -8 ) in northwestern parts of Zagros indicating less frequent moderate to large earthquakes. Recurrence intervals of large earthquakes (M>6) in southeastern parts of Zagros (17, 43 and 48 years) and central parts of Zagros (24, 27 and 59 years) are shorter than northwestern parts (27, 51, 79 and 130 years).

20p meriday 26-04-2019 15 2   Download

In this paper, a model of earthquake forecast is presented to assess the long-term probabilities of future earthquakes with moderate magnitudes for a region including Iran (latitude 25-40° and longitude 44-62°). The model estimates a coupled rate of magnitude, space and time for future seismicity using a spatial-temporal Poisson process.

8p meriday 26-04-2019 23 0   Download

The main goal of an Earthquake Early Warning (EEW) system is to reduce the damaging effects of the hazardous earthquakes. The characterization of an earthquake for EEWincludes most importantly, the estimates of itssize (magnitude) and location. In this study, the distance and magnitude of the selected earthquakes were estimated using the envelope ofthe initial part of the P-waveforms deploying a single seismic record.

11p meriday 26-04-2019 27 0   Download

The results indicate that two decades after the event, more than 80% of the existing buildings are still seismically vulnerable, which shows that recovery efforts has failed to improve the region’s safety.

13p meriday 26-04-2019 23 1   Download

In this paper, an attempt is made to examine the efficiency of an approximate incremental dynamic analysis (IDA) method to estimate the collapse capacity of conventional steel structures. To this purpose, two partially collapsed steel structures are selected. Both two structures are comprised of an ordinarymoment resisting frame systemin one direction, and a braced frame system in other perpendicular direction.

13p meriday 20-04-2019 11 0   Download

This building had much better performance than two others and experienced less loss. Moreover, the results of the analysis show that the collapse criteria related to the seismic evaluation codes are non-conservative. The results of this survey imply that the proposed method can precisely forecast the collapse or non-collapse of the studied buildings. Therefore, it would be recognized as a reliable method for collapse assessment.

11p meriday 20-04-2019 17 0   Download

Post-earthquake observations showed that damages in steel structures were mostly due to poor construction quality including lack of proper welding in connections, extent of irregularities of the structural system, false structural design, local site effects, and finally lack of enough supervision by "Iran Construction Engineering Organization" (IRCEO) and other responsible organizations. In this paper, observed damages to steel structures were examined and explaneed in detail.

14p meriday 20-04-2019 16 1   Download

In thisstudy, seismological aspects ofthe 2017 Sarpol-e Zahab earthquake has been investigated. The Sarpol-e Zahab earthquake, of magnitude 7.3 (Mw), occurred in southwestern Iran on November 12, 2017. Here, we investigated the properties of the strong ground motions of the earthquake using the records provided by Iranian Strong Motion Network (ISMN).

9p meriday 20-04-2019 21 1   Download