Geodynamics Research International Bulletin

8

Authors: Javad Izadyar

At 14.46 of March 11, 2011, a giant earthquake with magnitude of 9 occurred in a wide area along the Pacific coast of Tohoku in northeast of Japan. The earthquake generated a huge tsunami and caused 15729 fatalities and 4539 missing in the Hokkaido, Tohoku and Kanto regions. Continuous GPS data revealed coastal subsidence as great as one meter along the coast of the Tohoku area. CMT solution of the earthquake shows a shallow dipping thrust mechanism with a strike parallel to the Japan trench, indicating an interaplate earthquake associated with the subduction of the Pacific plate. Source process analysis using strong motion data of the earthquake indicated that the main fault has 450 km length and 150 km width and also showed that the rupture initiated from earthquake hypocenter and propagated towards both south and north directions.

10

Authors: Shahab Adeli, Khalil Valizadeh Kamran, Behroz Sari Saraf, Ali Mohhamad Khorshiddoust

Natural hazards are adverse events that occur in the majority of cases and are associated with human and financial losses. The earthquakes dangerous have high importance for Iran because of this country position on the one of most dangerous belt of seismic (Ailpine– Himalayan) in the world. Application of remote sensing technology and satellite image processing can compensate the lack of ground stations and earthquake observation and forecasting system improvement. In this research, we used this technology for analyzing thermal anomalies of a few days before the recent earthquake in Saravan with MODIS sensor of Terra satellite data by using split window algorithm and identifying and providing the resulting thermal anomalies to predict the nearly occurring earthquake in other areas.

11

Authors: Sarfraz Khan - Ahmad Hammad Khali

The Kotli area is a part of sub to lower Himalayas, and lies to the south east of the great syntaxial bend. The main objective of the present work was to test the site response analysis to interpret the damping effects after Muzaffarabad, 2005 earthquake on soils deposited at four sites (Fatehpur, Bernala, Plandri, Shensha) of Disstt. Kotli, NW of Pakistan. In the study areas, the site response at the vertical seismograph arrays of Kashmir earthquake (1995) having PGA of 0.017 was analyzed and it is scaled to PGA value of Muzaffarabad Earthquake. A non-Linear program is used, and site response models (damping curves, stress to strain curves, strain energy curves, frequency response curves and acceleration response curves) were constructed using shear and compression wave velocity profiles from upholes, and geotechnical data available at the four sites. In this analysis, other nonlinear and geometrical effects like stiffness reduction and liquefaction were neglected. By using soil parameters, a new damping curves for soils are constructed for the four different sites. The four areas are tested for response spectrum with increasing damping ratio (5%, 10%, 20%, 30% and 40%). The results of PGA, PGV and PGD for each area were obtained using 5% critical damping ratio and plotted on tri-linear diagram.

12

Authors: Mehrdad Ansaripour, Habib Rahimi

In this study the Coda waves application have been investigated to obtain the source and path effects for the Tehran region. Methods are used here to obtain the attenuation of path is normalized method and for an estimate of the magnitude, the length of time coda waves is used. A Reliable estimate of the magnitude and the full examination of magnitude (Mc) from the earthquake catalogs is necessary for any analysis of seismicity, (Habermann, 1987). We used the records of seismic waves from Geophysics Institute of University of Tehran for Mc was calculated as follows. Frankel (1990) used for the first time coda normalized methods to estimate the number of stations. That for inactive areas and are rare and low data this method can be useful. We used recorded accelerograms Kojor of around the epicenters of earthquakes that led to we are calculate the absorption coefficient with using normalized coda waves (Aki, 1980) for all recorded stations that had good signal to noise ratio of quality factor.

13

Authors: Camila Yazdanfar, Maryam Agh Ataby, Fereshte Jaafari Hajati

The Boushehr earthquake occurred on April 9 2013, with a moment magnitude of 6.3. Moderate surface ruptures were found, that’s why no one can exactly define the fault that was responsible for the earthquake. The aim of this research is to explore the fault interaction through static stress transfer between the main shock and its aftershocks and another main shock (Borazdjan Earthquake). In this paper, we use Coulomb Stress Changes model (ΔCFF) in order to investigate the fault interaction between the main shocks and aftershocks. We used a main shock and aftershocks which were happened up to more than 10 mounts. Data were entered in Coulomb 3.2 software. The two planes that are reported in focal mechanism solutions (derived from Harvard CMT and Centroid Lat. and Lon. derived from IRSC) are tested. Coulomb stress Model areas and spatial distribution of aftershocks and the location of main shock are compared in every case. As it can be seen in the diagrams, there is a significant correlation between stress–enhanced regions and spatial distribution of aftershocks and the latest mainshock, when the fault plane is 157/41, SW.

17

Authors: Masoud Mashhadi Hoseinali, Mona Ghodsi

In this article, the existing global and local tecniques of modeling the Ionosphere are introduced. The efficiency of these techniques in analyzing the precursores of earthquakes are analyzed and compared together. Two earthquakes in the Gulf of Moro (Philippine) and the Bonin islands (Japan) are used for this purpose. The one month average of TECs which are computed in a regular grid and its standard deviation is used as a benchmark here. The obtained results emphasize on a significant correlation between ionospheric anomalies and the time of earthquakes whose magnitudes are larger than 7 in the so-called Richter measurement scale. High solar activities as well as geomagnetic storms don’t disturb the analysis process when local Ionosphere models are used, but the separation of the earthquake precursors from the other sources of perturbation is impossible when the global models are used.

6

Authors: Mandana Zahrkesh, Hossein Morovati, Mohsen Pour Kermani

The Geodynamic developments in the natural coast of the region disrupt the natural, balanced and stable trend of coastal reciprocal behavior which leads to reactions such as sedimentation and local erosion depending on new conditions. These changes will have an adverse effect on the performance of the instrument and the created structures. In other words, the structural characteristics of coastal and marine shoreline in the area have a mutual influence on each other.Geodynamic developments in the natural coast of the region disrupt the natural, balanced and stable trend of coastal reciprocal behavior which leads to reactions such as sedimentation and local erosion depending on new conditions. These changes will have an adverse effect on the performance of the instrument and the created structures. In other words, the structural characteristics of coastal and marine shoreline in the area have a mutual influence on each other. Therefore, the studies on implementation or expansion of coastal and marine structures should investigate the effects on the coastal regions under study. In this research, the total sediment transport rate from different directions was calculated by comparing the Bijker’s (1971) formula, the Van Rijn’s formula and the CERC formula as well as sediment transport rate considering the prevailing characteristics of sea waves, sea currents, fluctuation of Caspian Sea levels, and sediment grading curve. Then, the total sediment transport rate was analyzed using the Wet Lay-up statistical technique (Benny Byat and Patrick,2013).

10

Authors: Seyed Ahmad Babzadeh

The Sistan suture zone (Eastern Iran) belongs to the Tethian suture, which was formed during the Early Cretaceous to Paleogene. This suture zone is divided into two tectono-sedimentary provinces (Gazik and Sahlabad) that reflect different paleo-geographic domains. The zone was created as a marginal basin, which opened prior to the Early Aptian between the Lut block and Afghan margin as a consequence of northeastward subduction of the Neo-Tethys Ocean. The active margin accretionary facies accumulated in the eastern region of this suture (Gazik Province) during the Late Cretaceous (pre-Maastrichtian), whereas passive margin facies and deep basin facies were deposited in western region (Sahlabad Province) at this time. This narrow oceanic domain was closed in three steps with an east to west progradation, in the Maastrichtian to Late Eocene. This interpretation results from new microbio-stratigraphic data from the accretionary facies and Ophiolitic mélanges emplaced in this narrow mobile belt.

13

Authors: Mohammad Khalaj, Mohsen Pourkermani, Mehran Arian

Morphometric parameters are as a method for determining the speed of active tectonic processes. Since then the active regions were identified by qualitative analysis, the speed of these processes find applications to earthquake hazard assessment. The purpose of this article is measuring of morphometric parameters in south central Alborz range, to determine the rate of active tectonics. Therefore, the quantitative morphometric parameters were measured and evaluated for the mountains of north Tehran, Karaj, Anti-Alborz. The results show that the East of the South Central Alborz range is more active than its West. Tectonics activity, away from the side of Alborz mountain range to central Iran also will be decreased