No abstract available

[en] Full text: Character of the spread of the plate-tectonic structures of Paleotethys and its oceanic basins including plan and age of the deformation as well as relation between Paleotethys and Mesotethys and the other issues are urgent debatable problems of the Paleozoic-Triassic geology in the region. As a result of complex geologic, magmatic, tectonic, paleo bio geographic, geophysical and cosmotectonic studies in the Caucasus, Zacaspian and Iran there were constructed geo dynamic maps on the paleo tectonic basis for certain time sections starting from the Cambrian transition stage till the Triassic models of Paleotethys evolution for two near-meridional geo traverses Arabian margin of Gondwana and in the north it crosses the East-European platform. In the Cambrian the change of the carbonaceous facies by the arkosicsandstones and quartzites in the Gondwana and in the East-European platforms is associated with the absolute elevation and washout of the Caspian-Caucasian shield. This is a precursor of more significant events and processes. There probably occurred a large structural reconstruction in the boundary of the Cambrian and the Ordovician associated with the beginning of the opening of the Caucasian, Turkestan and Ural pale oceans. As a result of the continental riftogenesis that in the next stage is transformed from the rifting into the spreading of the oceanic crust the double deep-water basins of Paleotethys were separated. The closure of neo-Paleotethys in the late Triassic was preceded by the crack of Gondwana and location of a system of the branching rifting and spreading of Mesotethys

[en] Six hundreds and eighty earthquakes causing significant damage have been recorded since the 7. century in Japan. It is important to recognize faults that will or are expected to be active in future in order to help reduce earthquake damage, estimate earthquake damage insurance and siting of nuclear facilities. Such faults are called 'active faults' in Japan, the definition of which is a fault that has moved intermittently for at least several hundred thousand years and is expected to continue to do so in future. Scientific research of active faults has been ongoing since the 1930's. Many results indicated that major earthquakes and fault movements in shallow crustal regions in Japan occurred repeatedly at existing active fault zones during the past. After the 1995 Southern Hyogo Prefecture Earthquake, 98 active fault zones were selected for fundamental survey, with the purpose of efficiently conducting an active fault survey in 'Plans for Fundamental Seismic Survey and Observation' by the headquarters for earthquake research promotion, which was attached to the Prime Minister's office of Japan. Forty two administrative divisions for earthquake disaster prevention have investigated the distribution and history of fault activity of 80 active fault zones. Although earthquake prediction is difficult, the behaviour of major active faults in Japan is being recognised. Japan Nuclear Cycle Development Institute (JNC) submitted a report titled 'H12: Project to Establish the. Scientific and Technical Basis for HLW Disposal in Japan' to the Atomic Energy Commission (AEC) of Japan for official review W. The Guidelines, which were defined by AEC, require the H12 Project to confirm the basic technical feasibility of safe HLW disposal in Japan. In this report the important issues relating to fault activity were described that are to understand the characteristics of current fault movements and the spatial extent and magnitude of the effects caused by these movements, and to estimate the spatial extent of future fault movements and their effects on the geological environment. One conclusion from the report is that present active faults in Japan have moved repeatedly for at least the last several hundred thousand years and are likely to continue to do so under the same stress field in the next a hundred thousand years. The latest knowledge relating to active faults and features of active faults to be considered for the stability of geological environments are described. (author)

[en] Complete text of publication follows. Kutch is demarcated as zone V in the seismic zoning map of India and the Bhuj earthquake of 26^th January, 2001 with a magnitude of 7.8, is considered as one of the largest intraplate earthquakes. Major part of the basin is covered by the inaccessible Great Rann of Kutch and the little Rann of Kutch due to which the existing geophysical data coverage is very poor. To have a clear picture of the structural and tectonic frame work and understand the lithology of the region a semi detailed high-resolution airborne magnetic survey, at an altitude of 200m and line spacing of 1km, was conducted during the period January to May 2008, covering an area of 56593 sq. km over the Kutch basin and surrounding areas. The anomaly map depicts several major E-W, NE-SW and NW-SE oriented lineaments and faults, which are extending up to the Indian plate boundary. All major geologic and tectonic elements including the trap flows, the Kutch Main land Fault, the volcanic islands, extension of the Cambay basin towards north and Delhi-Aravalli towards the west, etc. find expression on the anomaly map. The shallow level magnetic sources are identified as trap flows and volcanic plugs. At deeper level, the whole region can be divided into two units corresponding to the Dharwarian and Delhi-Aravalli trends. These two tectonic units are separated by a NW-SE trending transition zone. Similar pattern is evident in the seismic tomography map at depths of 20 and 25km. Few magnetic and gravity profiles have been selected across this transition zone to throw light on its tectonic setting. Available MT, GPS, Gravity and Heat flow data have been utilized to arrive at a geodynamical model of the seismically active Kutch region. Results of this analysis will be presented.

[en] The Uruguay and magmatic associations with alkaline affinity are locally developed related either to final distensional events of the Brasiliano Cycle or to the Mesozoic tectonics. Preliminary results correspondent to the plutono-volcanic activity recognized in the Valle Chico Alkaline Massif, focusing petrographical and geochemical variations from Shoshonitic Associations to potassic transitional alkaline, associations, are presented in this paper.(author)

[en] In the Sierra Arana area, dextral transcurrent faults form a set of long and narrow E-W tectonic bands, some of which are filled by Oligo-Aquitanian and Cretaceous sediments deeply squeezed among Jurassic carbonates. These bands form a “flower structure” which higher blocks, cut by the faults, fallen over Oligo-Aquitanian sediments, forming a tectonic mélange. The crest zone of Sierra Arana indicates the position of a great reversed south verging anticlinal. The elements situated directly to the south of Sierra Arana, are attributed to a very internal Subbetic or to the Dorsal, and seem to correspond to the paleogeographic passage from the Subbetic to the Malaguide Complex. (Author)

[en] This paper presents the landslide hazard assessment and slope-failure function using two Newmark displacement models regressed by regional and global station records. Taking the 2008 Wenchuan M_w 7.9 earthquake area as an example, based on the topographic and geological data of the study area, we prepared a factor-of-safety (Fs) map and a critical acceleration (a_c) map, respectively. Then using these two simplified Newmark models, two displacement maps were compiled by combining the a_c map and peak ground acceleration (PGA) map. By virtue of the actual landslide inventory of the W enchuan earthquake, we constructed the slope-failure probability curves of the two Newmark models. The results show that the abilities to predict landslide occurrence of the two simplified Newmark models are largely identical, by which the assessment results can well delineate the macroscopic distribution of coseismic landslides, and most predicted landslide cells are distributed on the two sides of the Beichuan-Yingxiu fault, especially Pengguan complex rock mass in the hanging wall of this fault. The probability equations of two Newmark models are roughly the same, though the parameters vary slightly. The probability equation proposed in this paper can be applied to the Wenchuan region and other areas with similar tectonic environments.

No abstract available

[en] The continuous nature of GPS time series is complex. Fractal analysis can give a better understanding of the complex nature of the GPS time series. Here we have considered the North and East components GPS position time series of the Patna and Ranchi station network (in which Patna site has suffered a coseismic displacement of 7$\pm$3 mm due to the 25th April 2015 Gorkha Earthquake). We found variation in scaling exponent β, before and after April 2015, Gorkha, Nepal Earthquake. The study region consists of the Bihar-Jharkhand area, where we have taken two of the four permanent sites of the GPS network to compare the results of variation in scaling exponents for the three sites. The variation in exponents (β) value is dependant on the distribution of tectonic elements at the two sites. The three sites show lower values of exponents (β) before the earthquake than after the earthquake signifying high seismic energy and convergence due to strain accumulation compared to after the main event. A combined study of GPS and Scaling exponents will represent the hazardous zone in India's South Himalayan region.

[en] This study reviews the history of seismometry in Iran and specifically the evolution of Iranian Seismological Center’s (IRSC) seismic network and investigates the artifacts and systematic errors of this center’s earthquake catalog. Our analysis indicates instability of magnitude estimation in the IRSC catalog to the extent that in the western and eastern parts of Iran, events with the same USGS reported m_b magnitude could result in M_N values 0.3 units apart. This catalog is contaminated with quarry and mine blasts, in which about 19% of the reported events are most likely not tectonic earthquakes. In addition, heterogeneity of magnitude of completeness as a function of space and time is observed. While M_c has gradually improved since 2006, its reduction in different parts of the country varies between 0 to 0.5 units of magnitude. In addition to artifacts, more than 54% of the reported events were located using a simplified velocity model and need to be relocated using more accurate velocity models. Moreover, in the hypocenter determination of about 7% of earthquakes, at least data from one station with wrong coordinates was employed. For these two groups of events, a clear dependence exists between the azimuthal gap and the value of the observed shift in the location parameters; with increasing the azimuthal gap, the shift increases. Investigations on the manually picked phases in the IRSC catalog show a large number of phase misidentification cases which are the other source of systematic errors. Examining the depth reported for events associated with mine blasts in a region in southern Iran implies systematic errors and high overestimation of depth for these events. The reported depth for most of these blasts is more than 10 km.