The afterglow of a dense molecular cloud after the passage of a cosmological gamma-ray burst

Bolometric light curves for the afterglow resulting from the passage of a gamma-ray burst through a molecular cloud are computed. The profile and duration of the afterglow light curve depend strongly on the distribution of matter in the cloud, the degree of collimation of the gamma-ray radiation, and the observing conditions. The peak can be reached as soon as seven days (the gamma-ray burst is located at some distance from the center of a molecular cloud with small-scale density enhancements), or as long as one to three years (the gamma-ray burst is located at the center of a uniform molecular cloud) after the burst. The bolometric luminosity of the re-radiated signal can reach 6.5 × 10⁴² erg/s.     

Pyroclastic volcanism in Papaghni sub-basin,Andhra Pradesh: Significant Paleoproterozoic tectonomagmatic event in SW part of the Cuddapah basin,Eastern Dharwar craton

Detailed field and petrological studies in Vanambayi-Lingala-Lopatnutala section and old Kadiri Ghat-Pulivendela section in SW part of the Proterozoic Cuddapah basin of Eastern Dharwar craton brought to light the occurrence of hitherto unreported two significant phases of pyroclastic volcanic activity associated with the Vempalle Formation in Papaghni sub-basin. Occurrence of a significant pyroclastic agglomerate at the contact zone of Vempalle dolomite of Papaghni Group and Pulivendela quartzite of Chitravathi Group represents a significant event of the mafic phase of pyroclastic volcanic activity, while the finely laminated felsic tuff within the intercalated reddish siltstone, chert and dolomite sequence in the lower part of Vempalle Formation represents the felsic phase of pyroclastic activity. Studies indicate that the pyroclastic agglomerate zone in Vanambayi-Lingala-Lopatnutala section is a classical example of pyroclastic volcanism wherein the highly vesicular rock with rounded basalt clasts often exhibit embayed contact of welded nature with the matrix. The pyroclastic zone reported in the present paper particularly at the interface of Vempalle Formation and Pulivendela quartzite in Vanambayi-Lingala-Lopatnutala section represents a significant tectono-magmatic event of explosive volcanic activity that is contemporaneous with the culmination of the carbonate precipitation of Vempalle dolomite and marks the termination of sedimentation in Papaghni Group in southwestern part of Cuddapah basin during Paleoproterozoic times.     

The catastrophic flood in Transbaikalia (Central Asia) in 1897: case study

The territory of Transbaikalia (Russia) is subject to occasional large-scale flooding. One of the most significant events in terms of scale and consequences is the historical flood that occurred in August 1897. In this article, we have tried to reconstruct the flood event. For this purpose, we have used all available historical sources (official statistical data, newspaper publications). The flood was observed almost simultaneously in two river basins (the Selenga and Shilka rivers). The main cause of the catastrophic flood was the abnormally intensive rainfall in the Hentey Mountains (Mongolia) and in Chikokonsky Ridge (southern Transbaikalia) in summer 1897. We have singled out four flood stages on the basis of the dates of flooding in different settlements. The flooding was accompanied by silting of considerable areas, and formation of new channels in local places. The flood in August 1897 in Transbaikalia, Russia, clearly demonstrated the vulnerability of both the environment and society to such catastrophic events.     

Exposure history of the Torino meteorite

Abstract— We determined He, Ne, Ar, ¹⁰Be, ²⁶Al, ³⁶Cl, and ¹⁴C concentrations, as well as cosmic-ray track densities and halogen concentrations in different specimens of the H6 chondrite Torino, in order to constrain its exposure history to cosmic radiation. The Torino meteoroid had a radius of ～20 cm and travelled in interplanetary space for 2.5–10 Ma. Earlier, Torino was part of a larger body. The smallest possible precursor had a radius of 55 cm and a journey through space longer than ～65 Ma. If the first-stage exposure took place in a body with a radius of >3 m or in the parent asteroid, then it lasted nearly 300 Ma. The example of Torino shows that it is easy to underestimate first-stage exposure ages when constructing two-stage histories.     

Main stages of evolution of matter in the universe. I

The problem of the equation of state of cosmic matter is discussed and the constants of integration in the Friedmann solutions are determined. Translated from Astrofizika, Vol. 40, No. 1, pp. 117–124, January–March, 1997.     

Assessment of direct determination uncertainties of incoming radiation fluxes associated with the ship motion

The paper considers the impact of ship oscillations on the accuracy of radiation flux measurements in the absence of a gyroplatform and a gimbal suspension. As an example, we discuss the simultaneous determinations of the radiation fluxes and careen during the 20th mission of the R/V Akademik Joffe. A sampling rate of 10 s was found to be sufficient to neglect the careen when estimating the hourly sums of the short-wave solar radiation at sun heights exceeding 10°. At smaller sun heights, the careen is able to effect the estimates of the solar radiation within 20%. Due to the harmonic nature of such oscillations, these errors tend to become low against the instrumental accuracy if one deals with the hourly and daily means of the short-wave solar radiation fluxes during sufficiently long observations. In addition, a significant effect occurs at rather low sun and a sea roughness of Beaufort number 4 or higher. A rough sea is usually associated with the diminishing of the clear sky area and the higher repeatability of the cloudiness conditions, which reduces the effect of rolling upon the measurement accuracy.     

Distribution of Ixodes ricinus L., 1758 and Ixodes persulcatus Shulze, 1930 (Parasitoformes,Ixodidae) in Russia and adjacent countries in view of observable climate changes

Possible changes in the area inhabited by the ticks Ixodes ricinus and Ixodes persulcatus, the main transmitters of tick-borne encephalitis and Lyme disease in Russia, caused by temperature changes in 1976–2005 compared to 1946–1975 are discussed. It is shown that these changes could result in some areal expansion of these species. In the European part of Russia, I. ricinus expanded its areal boundaries to the east 100–300 km. I. persulcatus expanded its areal in the Asian part of Russia. Its boundary moved to the north and northeast 100–300 km. Areal expansion both of species has not been observed.     

Decompression P–T path of coesite eclogite to granulite from Weihai, eastern China

Granulitized coesite-bearing eclogite from Weihai, northeastern part of the Shandong peninsula, eastern China was studied in detail to reveal the modification of mineral chemistry during decompression metamorphism. Considerable modification of chemical composition is recorded in clinopyroxene that occurs both as inclusions in garnet and as a matrix mineral. Careful examination of chemical variation with the change in microstructure made it possible to estimate the equilibrium composition of minerals at the coesite eclogite and garnet granulite stages. We were able to define three reference points on the P–T path, namely, coesite eclogite (3 GPa, 660±40°C), granulite (1 GPa, 700±30°C) and amphibolite (0.9 GPa, 600±20°C). The path thus obtained is similar to those obtained by previous workers and supports nearly isothermal decompression of coesite eclogite.     

A polar method for obtaining wave resonating quadruplets in finite depths

A polar method for obtaining wave resonating quadruplets {K₁, K₂, K₃, K₄} in the computation of nonlinear wave–wave interaction source term of the wave model is presented with results for both deep and finite water depths. The method first determines the end radial points of the locus equation for K₂, for each set of input wave vectors (K₁, K₃) on the symmetry. The locus of K₂ (and hence K₄) is then traced in the anti-clockwise direction starting with the maximum radial point on the line of symmetry. It is shown that when k₃>k₁, the number of points on the locus varies when the orientations of the input wave vectors are changed and reduces when the difference in the magnitude of the input wave vectors is increased. A significant advantage in this method is that the angular increment on the locus for K₂ can be kept constant.     

Paleozoic granitoid magmatism of the eastern part of the Central Asian Fold Belt and formation of large ore deposits

Evidence on the Paleozoic granitoids of the eastern part of the Central Asian Fold Belt (CAFB) was analyzed. A tectonic chart of orogenic belts was compiled. Sketch maps were constructed for the geodynamic settings of the formation of Paleozoic granitoids and the extensiveness of their occurrence. Two types of deep controlling structures were distinguished: zones of lithospheric faults and plumes, including the newly recognized Jiamusi-Bureya plume. It was sown that the distribution of large and superlarge Paleozoic ore deposits is related to these structures, primarily to plumes. Sites promising for large and superlarge deposits related to the Paleozoic granitoid magmatism were determined in the Russian Far East.