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1.
Since 2002 the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) in Udine (Italy), the Agencija Republike Slovenije za Okolje (ARSO) in Ljubljana (Slovenia) and the Zentralanstalt für Meteorologie und Geodynamik (ZAMG) in Vienna (Austria), are collecting, analyzing, archiving and exchanging seismic data in real time, initially in the framework of the EU Interreg IIIa Italia-Austria project “Trans-national seismological networks in the South-Eastern Alps”. As outcome of the successful cooperation, in the 2013 OGS, ARSO and ZAMG decided to officially merge their seismic monitoring efforts into the “Central and Eastern European Earthquake Research Network—CE3RN”. This work reports the results of a nine-month real-time test of the earthquake early warning (EEW) algorithm probabilistic and evolutionary early warning system carried out at the CE3RN. The study allowed identifying the actions to be implemented in order to let the CE3RN become in the next future an efficient cross-border EEW system. 相似文献
2.
The Malkhan granite-pegmatite system located in Central Transbaikalia, in the southwestern portion of the Malkhan-Yablonovy
structure-formational zone of the Caledonian folding comprises two granite massifs (Bolsherechensk and Oreshny) and a miarolitic
pegmatite field of the same name, which adjoins the Chikoi deep-seated fault and Lower Cretaceous Chikoi rift depression in
the north. The first 40Ar/ 39Ar data were obtained on porphyritic biotite granites of the Oreshny massif and on K-feldspar, muscovite, and lepidolite from
the Oktyabrskaya pegmatite vein. According to these data, the age of the granitepegmatite system is 123.8–127.6 Ma, which
is consistent with the age of Lower Cretaceous rocks from the Chikoi depression. The intimate spatial relationship and isochronism
between the Chikoi depression and the Malkhan granite-pegmatite system are strongly suggestive of a rift regime that affected
its evolution, thus highlighting the need to regard the evolution of this system as being intimately related to depression
development. Such a model can easily be realized within the framework of the concept of a metamorphic core complex, which
was used to explain the nature of Transbaikal-type rift depressions and conjugate granite-gneiss swells. 相似文献
4.
In this work, accumulation of cosmogenic radionuclide 7Be in seven species of lichens was determined using HPGe detectors in autumn season. Ramsar city which is located in the north of Iran as one of the high-level natural radiation areas in the world was considered. Lichen species represented good potential in accumulation of 7Be radionuclide. The foliose species of Xanthoria parietina with the highest activity concentration value of 112.8 ± 1.8 Bq kg ?1 was introduced as bioindicator for accumulation of 7Be radionuclide. Cladonia rangiformis species has got minimum concentration of 64.5 ± 0.8 Bq kg ?1. Also from thallus morphology viewpoint, results showed that 7Be accumulation in foliose species is higher than in fruticose and crustose lichens species. Also there was relatively large positive correlation between 7Be and 226Ra activity concentrations in lichens species. 相似文献
5.
U-Pb systems were examined in samples (ranging from 4 to 10 cm 3 in volume) of ore material taken from along a 3.5-m profile across a zone of U mineralization exposed in an underground mine at the Strel’tsovskoe U deposit in eastern Transbaikalia. The behaviors of two isotopic U-Pb systems ( 238U- 206Pb and 235U- 207Pb) are principally different in all samples from our profile. While the individual samples are characterized by a vast scatter of their T( 206Pb/ 238U) age values (from 112 to 717 Ma), the corresponding T( 207Pb/ 235U) values vary much less significantly (from 127 to 142 Ma) and are generally close to the true age of the U mineralization. The main reason for the distortion of the U-Pb system is the long-lasting (for tens of million years) migration of intermediate decay products in the 238U- 206Pb(RD 238U) in the samples. This process resulted in the loss of RD 238U from domains with high U concentrations and the subsequent accommodation of RD 238U at sites with low U concentrations. The long-term effect of these opposite processes resulted in a deficit or excess of 206Pb as the final product of 238U decay. The loss or migration of RD 238U are explained by the occurrence of pitchblende in association with U oxides that have higher Si and OH concentrations than those in the pitchblende and a higher +6U/ +4U ratio. The finely dispersed character of the mineralization and the loose or metamict texture of the material are the principal prerequisites for RD 238U loss and an excess of 206Pb in adjacent domains with low U concentrations. Domains with low U contents in the zone with U mineralization serve as geochemical barriers (because of sulfides contained in them) at which long-lived RD 238U( 226Ra, 210Po, 210Bi, and 210Pb) were accommodated and subsequently caused an excess of 206Pb. The 235U- 207Pb system remained closed because of the much briefer lifetime of the 235U decay products. This may account for the significant discrepancies between the T( 206Pb/ 238U) and T( 207Pb/ 235U) age values. RD 238U was most probably lost via the migration of radioisotopes at the middle part and end of the 238U family (starting with 226Ra). The heavy Th, Pa, and U radioisotopes ( 234Th, 234Pa, 234U, and 230Th) that occur closer to the beginning of 238U decay, before 226Ra, only relatively insignificantly participated in the process. Our results show that the loss and migration of RD 238U are, under certain conditions, the main (or even the only) process responsible for the distortion of the U-Pb system. 相似文献
7.
The investigation of regionally extensive groundwater systems in remote areas is hindered by a shortage of data due to a sparse observation network, which limits our understanding of the hydrogeological processes in arid regions. The study used a multidisciplinary approach to determine hydraulic connectivity between the Great Artesian Basin (GAB) and the underlying Arckaringa Basin in the desert region of Central Australia. In order to manage the impacts of groundwater abstraction from the Arckaringa Basin, it is vital to understand its connectivity with the GAB (upper aquifer), as the latter supports local pastoral stations and groundwater-dependent springs with unique endemic flora and fauna. The study is based on the collation of available geological information, a detailed analysis of hydraulic data, and data on environmental tracers. Enhanced inter-aquifer leakage in the centre of the study area was identified, as well as recharge to the GAB from ephemeral rivers and waterholes. Throughout the rest of the study area, inter-aquifer leakage is likely controlled by diffuse inter-aquifer leakage, but the coarse spatial resolution means that the presence of additional enhanced inter-aquifer leakage sites cannot be excluded. This study makes the case that a multi-tracer approach along with groundwater hydraulics and geology provides a tool-set to investigate enhanced inter-aquifer leakage even in a groundwater basin with a paucity of data. A particular problem encountered in this study was the ambiguous interpretation of different age tracers, which is attributed to diffusive transport across flow paths caused by low recharge rates. 相似文献
8.
The effect of CaO, Na 2O, and K 2O on ferric/ferrous ratio in model multicomponent silicate melts was investigated in the temperature range 1450–1550?°C at 1-atm total pressure in air. It is demonstrated that the addition of these network modifier cations results in an increase of Fe 3+/Fe 2+ ratio. The influence of network modifier cations on the ferric/ferrous ratio increases in the order Ca?<?Na?<?K. Some old controversial conceptions concerning the effect of potassium on Fe 3+/Fe 2+ ratio in simple model liquids are critically evaluated. An empirical equation is proposed to predict the ferric/ferrous ratio in SiO 2–TiO 2–Al 2O 3–FeO–Fe 2O 3–MgO–CaO–Na 2O–K 2O–P 2O 5 melts at air conditions. 相似文献
9.
Gamma activity from the naturally occurring radionuclides namely, 226Ra, 232Th, the primordial radionuclide 40K was measured in the soil of Cuihua Mountain National Geological Park, China using γ-ray spectrometry technique. The mean
activity of 226Ra, 232Th and 40K were found to be 27.2 ± 6.5, 43.9 ± 6.2 and 653.1 ± 127.6 Bq kg −1, respectively. The concentrations of these radionuclides were compared with the typical world values and the average activities
of Chinese soil. The radium equivalent activity, the air absorbed dose rate, the annual effective dose rate, and the external
hazard index were evaluated and compared with the internationally approved values. All the soil samples have Ra eq lower than the limit of 370 Bq kg −1 and H
ex less than unity. The overall mean outdoor terrestrial gamma dose rate is 66.3 nGy h −1 and the corresponding outdoor annual effective dose is 0.081 mSv. 相似文献
10.
Various experiments involving the measurement of new, regenerated and total productivity using 15N and 13C tracers were carried out in the Bay of Bengal (BOB) and in the Arabian Sea. Results from 15N tracer experiments indicate that nitrate uptake can be underestimated by experiments with incubation time <4 hours. Indirect
evidence suggests pico- and nano-phytoplankton, on their dominance over microphytoplankton, can also influence the f-ratios.
Difference in energy requirement for assimilation of different nitrogen compounds decides the preferred nitrogen source during
the early hours of incubation. Variation in light intensity during incubation also plays a significant role in the assimilation
of nitrogen. Results from time course experiments with both 15N and 13C tracers suggest that photoinhibition appears significant in BOB and the Arabian Sea during noon. A significant correlation
has been found in the productivity values obtained using 15N and 13C tracers. 相似文献
13.
Resulting from study of the geological structure of the Franz Josef Land and Svalbard archipelagoes, this work presents new
17 40Ar/ 39Ar age datings for basalts taken during coastal expeditions in 2006–2010. Radiological age determination for intrusive units
(sills) located in the western part of Nordensciold Land (Spitzbergen Island) has been made for the first time. In relation
to use of the interpretation results of marine geological-geophysical data, the distribution peculiarities and time ranges
for Jurassic-Cretaceous basic magmatism within the studied regions of the Barents Sea continental margin and within the Arctic
as a whole are discussed. 相似文献
14.
Groundwaters of Primorye, including its coastal areas, were studied during the past ten years. The macro-and microelement composition of more than 130 samples showed that shallow groundwaters of southern Primorye with pH ranging between 5.4 and 8.4 contain oxygen (up to 10 mg/l) and typically have a mixed ionic composition. The microelement variations reflect both the natural features of the host rocks and possible anthropogenic pollution in the most populated areas. No seawater intrusions were recognized in the study areas, which is confirmed by the chemical composition of the waters, the oxygen and hydrogen isotopic composition of the groundwaters, the atmospheric precipitation, and the coastal seawaters of Primorye. In spite of the variations of individual components, the quality of the groundwaters used for potable purposes is rather satisfactory as compared to the Russian and the World Health Organization standards. At the same time, taking into account the increase of various microelements and biogenic components in the waters, the monitoring and control of the water composition is strongly recommended to preserve their potable quality. 相似文献
15.
Single crystals of B 2O 3 are needed for the precise determination of the refractive indices used to calculate the electronic polarizability α of 3-coordinated boron. The α(B) values in turn are used to predict mean refractive indices of borate minerals. Since the contribution of boron to the total polarizability of a mineral is very low, the synthetic compound B 2O 3 represents an ideal model system because of its high molar content of boron. Millimeter-sized crystals were synthesized at 1 GPa in a piston-cylinder apparatus. The samples were heated above the liquidus (800 °C), subsequently cooled at 15 °C/h to 500 °C and finally quenched. The refractive indices were determined by the immersion method using a microrefractometer spindle stage. The refractive indices n o = 1.653 (3) and n e = 1.632 (3) correspond to a total polarizability for B 2O 3 of α = 4.877 Å 3. These values were used to determine the electronic polarizability of boron of α(B) = 0.16 Å 3. Although the surface of the B 2O 3 crystals was coated with a hydrous film immediately after being exposed to air, its bulk crystallinity is retained for a period of at least 2 months. 相似文献
16.
Presence of young groundwater (post-1950) in the Goose River basin is demonstrated with 3H and 85Kr analyses. A total of 96 wells and four springs were sampled quarterly from 1999 to 2001 to determine the extent of any recent recharge and to what depth hydraulic continuity existed in the groundwatershed (33.3 km 2). Recharge groundwater is less than 50 years in about 31% ( 3H) to 37% ( 85Kr) of sampled wells and 75% of sampled springs. Young groundwater ages are recorded in wells up to 320 m in depth within fractured- and arsenic-bearing crystalline bedrock. Total arsenic 10 g L –1 occurs significantly in drinking water with young groundwater flowing through the pumping well intervals. As total occurs in 89% ( 85Kr) to 93% ( 3H) of all wells with post-1950 groundwater ages. Young groundwater recharge and elevated geogenic arsenic were discovered only in the anatectic granitoids and migmatized country rock of the southwestern part of the Goose River basin. 相似文献
17.
A novel complex continuous system of solid solutions involving vauquelinite Pb 2Cu(CrO 4)(PO 4)(OH), bushmakinite Pb 2Al(VO 4)(PO 4)(OH), ferribushmakinite Pb2Fe 3+(VO 4)(PO 4)(OH), and a phase with the endmember formula Pb 2Cu(VO 4)(PO 4)(H 2O) or Pb 2Cu(VO 4)(РО 3ОН)(ОН) is studied based on samples from the oxidation zone of the Berezovskoe, Trebiat, and Pervomaisko-Zverevsky deposits in the Urals, Russia. This is the first natural system in which chromate and vanadate anions show a wide range of substitutions and the most extensive solid solution system involving (CrO 4) 2– found in nature. The major couple substitution is Cr 6+ + Cu 2+ ? V 5+ + M3+, where M = Fe, Al. The correlation coefficients calculated from 125 point analyses are: 0.96 between V and (Fe + Al), 0.96 between Cr and (Cu + Zn),–0.96 between V and (Cu + Zn),–0.97 between Cr and (Fe + Al), and–0.97 between (Fe + Al) and (Cu + Zn). The substitutions V 5+ ? Cr 6+ (correlation coefficient–0.98) and to a lesser extent P 5+ ? As 5+ (correlation coefficient–0.86) occur at two types of tetrahedral sites, whereas the metal–nonmetal/metalloid substitutions, i.e., V or Cr for P or As, are minor. The substitution Fe 3+ ? Al 3+ is also negligible in this solid solution system. 相似文献
20.
The δ18O (SMOW) values of the Kirkpatrick Basalt (Jurassic) on Mt. Falla, Queen Alexandra Range, vary between +6.3‰ and +8.6‰ The apparent enrichment of these rocks in 18O excludes the possibility that they were altered by interaction with aqueous solutions of meteoric origin. The δ18O values of the flows correlate significantly with the initial 87Sr/ 86Sr ratios and all major elements. These correlations confirm the hypothesis that the basalt magma was contaminated by rocks of the continental crust through which it was extruded. Estimates of the chemical composition of the basalt magma and the contaminant, based on extrapolations of the new oxygen data, generally confirm earlier estimates based on extrapolations of initial 87Sr/ 86Sr ratios. The 87Sr/ 86Sr ratio of the uncontaminated basalt was 0.7093 which indicates that magma may have originated by melting either in old Rb-enriched lithospheric mantle under Antarctica or in the overlying crust, or both. 相似文献
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