首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
A gas geochemical precursor anomaly was identified prior to the October 2008 Nový Kostel (Czech Republic) earthquake swarm with a peak magnitude ML of 3.8. This anomaly was observed as a deviation of CO2 concentrations from the long‐term annual CO2 concentration trend in the gas extracted from the scree at the Nový Kostel and Old?i?ská gas monitoring stations, which are directly above the Plesná valley‐Po?átky and Mariánské Lázně fault systems. Both sites are located within the major focal zone of the NW Bohemian swarm earthquake region at the northern edge of the Cheb Basin. A decrease in CO2 concentration started at Nový Kostel in September 2008, 17 days before the swarm, opposite to the usually increasing annual trend in the autumn period, and ended with a nearly coseismic drop immediately prior to the onset of the first swarm. The CO2 concentrations at Old?i?ská, deviating from the annual trend, did not further increase after August 2008. The calculated horizontal strain field, based on the data of two permanent Global Navigation Satellite Systems stations, proved there was horizontal compression in this period. The increasing compression along the Plesná valley‐Po?átky and Mariánské Lázně fault systems during the stress build‐up reduced the fault permeability prior to this earthquake swarm as indicated by the decrease in CO2 concentration. The 17‐day duration of the earthquake precursor at Nový Kostel and about 65 days at Old?i?ská lie within the range of the precursor times that are hypothesized worldwide for an ML = 3.8 earthquake. The nature of earthquake precursors and their origin are discussed, for example, as an indication of changed fault permeability by stress build‐up in the case of the Nový Kostel swarm earthquake precursor or as fault opening in other cases.  相似文献   

2.
《Central Europe》2013,11(1):32-58
Abstract

This article traces the changes in two novels, Zdenňka Bezděková’s ?íkali mi Leni and Marie Majerová’s Bruno, made once the Communist-Party regime in Czechoslovakia was firmly established. For example, German paedophilia is changed to bullying in Bezděková and pre-war Czech political antisemitism deleted from Majerová. In both works Czech nationalist misoteutonism is changed into internationalist Communism. The author pays close attention to changes in language and style in both works. Though Majerová’s novel seems no longer to be read, Bezděková’s remains standard reading for adolescents, and in the twenty-fi rst century continues to be read with its somewhat rabble-rousing afterword by the novelist Karl Nový. The essay demonstrates how children can be made into things rather than people for the sake of a political ideology.  相似文献   

3.
We report new optically stimulated luminescence (OSL) dates from the Central European sites of K?lna, Stránská skála, Bohunice, Vedrovice V, Vedrovice Ia, Moravský Krumlov IV and Dzeravá skala, which date to the Middle–Upper Palaeolithic transition period. There are important unresolved questions surrounding the timing of archaeological events during this crucial period in European prehistory. Archaeological layers from this time period are at the limits of the 14C method and most of these sites lack good chronology. The results of this dating project suggest that some parts of the current chronological framework may need to be revised. Although in many cases our OSL results are broadly consistent with previous dates obtained by 14C, in other cases they reveal unexpected surprises. One OSL result from K?lna opens up the possibility that Neanderthals may have survived in this part of Europe past the 30 ka bp mark as has been argued for several Neanderthal sites in southern Europe. The large Szeletian assemblage recovered from Vedrovice V may be significantly older than previously thought, which undermines the idea that the Szeletian culture is exclusively an Early Upper Palaeolithic industry. More dating research is needed to confirm the more controversial results of this research.  相似文献   

4.
F. H. Weinlich 《Geofluids》2014,14(2):143-159
The ascent of magmatic carbon dioxide in the western Eger (Oh?e) Rift is interlinked with the fault systems of the Variscian basement. In the Cheb Basin, the minimum CO2 flux is about 160 m3 h?1, with a diminishing trend towards the north and ceasing in the main epicentral area of the Northwest Bohemian swarm earthquakes. The ascending CO2 forms Ca‐Mg‐HCO3 type waters by leaching of cations from the fault planes and creates clay minerals, such as kaolinite, as alteration products on affected fault planes. These mineral reactions result in fault weakness and in hydraulically interconnected fault network. This leads to a decrease in the friction coefficient of the Coulomb failure stress (CFS) and to fault creep as stress build‐up cannot occur in the weak segments. At the transition zone in the north of the Cheb Basin, between areas of weak, fluid conductive faults and areas of locked faults with frictional strength, fluid pressure can increase resulting in stress build‐up. This can trigger strike‐slip swarm earthquakes. Fault creep or movements in weak segments may support a stress build‐up in the transition area by transmitting fluid pressure pulses. Additionally to fluid‐driven triggering models, it is important to consider that fluids ascending along faults are CO2‐supersaturated thus intensifying the effect of fluid flow. The enforced flow of CO2‐supersaturated fluids in the transitional zone from high to low permeability segments through narrowings triggers gas exsolution and may generate pressure fluctuations. Phase separation starts according to the phase behaviour of CO2‐H2O systems in the seismically active depths of NW Bohemia and may explain the vertical distribution of the seismicity. Changes in the size of the fluid transport channels in the fault systems caused, or superimposed, by fault movements, can produce fluid pressure increases or pulses, which are the precondition for triggering fluid‐induced swarm earthquakes.  相似文献   

5.
Z. Nerudová 《Archaeometry》2020,62(2):410-426
This paper compares the quantification of different raw materials in a chipped stone assemblage by weight and by number at the site of Brno-Štýřice III in Moravia, Czech Republic. The use of the same reduction technology for all raw materials means that the Brno-Štýřice III assemblage is a good case study. The result demonstrates that semi-local raw material tends to dominate numerically, but in terms of weight, there is a significant change in the predominant raw material. The paper contextualizes the results in relation to other assemblages and discusses the possible reasons for this phenomenon.  相似文献   

6.
The Central Apennines are affected by frequent earthquakes of moderate magnitude that occur mainly within the upper part of the crust at depths of <15 km. A large number of cold gas emissions that are rich in CO2 are also found in the region. One particular vent with a high rate of degassing was equipped with a sensor to measure flow rates, which were recorded for a number of different periods between 2005 and 2010. Factors that could affect potentially CO2 flow rates include barometric pressure, atmospheric temperature, precipitation and local seismicity. Our analysis indicates that the periods of anomalous flow rate were related not to the environmental factors but probably to the deformative processes of the crust associated with the local seismicity. Local seismic events as expression of geodynamic processes occurred always before and during these anomalous gas flow periods. This correlation exists only for events that occurred eastwards of the gas emission site close to the Martana fault zone. We herein consider this correlation as indication for a continuous interaction between the field of static strain and the deep fluid pressure. An approximation of the fluid pressure transmission towards the gas emission site gives reasonable values of 1–10 m2 sec?1. To make comparisons with the long‐term effects of the static strain, we also recorded the short‐term effects of the dynamic release of strain induced by the series of strong earthquakes that took place in L’Aquila in 2009. We detected a significant anomalous flow rate that occurred at the same time as this seismic sequence, during which widespread degassing was induced around the focal zone.  相似文献   

7.
The Middle (Kretuonas 1B), Late Neolithic (Zemaitiške 1 and Zemaitiške 2) and Old Bronze Age (Kretuonas 1C) settlements near Kretuonas Lake (Svencioneliai district, Reskutenai village) yielded many artefacts of bone, antler, horn and teeth (750 in total). In the Kretuonas 1B assemblage, deer bones accounted for 50.5 per cent, elk bones 19.7 per cent and boar bones for 27.7 per cent of the total. In the Zemaitiške 1 and 2 settlements the respective portions were 27.7 and 62.0 per cent deer, 6.8 and 20.0 per cent elk and 10.1 per cent boar. In Kretuonas 1C the proportions were 10.9, 36.0 and 7.5 per cent respectively. In the Kretuonas 1B settlement 32 artefacts were identified, 16 from deer bone, four from elk and four from boar. In the Zemaitiške 2 settlement there were 114 artefacts of which 57 were identified to species. Of these, 39 were from deer, eight from elk and four from boar. Finally, in the Kretuonas 1C settlement, of the 531 artefacts found, 120 were identified to species and of these 49 were from deer, 44 from elk, nine from boar and nine from bear.  相似文献   

8.
We used hydrologic models to explore the potential linkages between oil‐field brine reinjection and increases in earthquake frequency (up to Md 3.26) in southeastern New Mexico and to assess different injection management scenarios aimed at reducing the risk of triggered seismicity. Our analysis focuses on saline water reinjection into the basal Ellenburger Group beneath the Dagger Draw Oil field, Permian Basin. Increased seismic frequency (>Md 2) began in 2001, 5 years after peak injection, at an average depth of 11 km within the basement 15 km to the west of the reinjection wells. We considered several scenarios including assigning an effective or bulk permeability value to the crystalline basement, including a conductive fault zone surrounded by tighter crystalline basement rocks, and allowing permeability to decay with depth. We initially adopted a 7 m (0.07 MPa) head increase as the threshold for triggered seismicity. Only two scenarios produced excess heads of 7m five years after peak injection. In the first, a hydraulic diffusivity of 0.1 m2 s?1 was assigned to the crystalline basement. In the second, a hydraulic diffusivity of 0.3 m2 s?1 was assigned to a conductive fault zone. If we had considered a wider range of threshold excess heads to be between 1 and 60 m, then the range of acceptable hydraulic diffusivities would have increased (between 0.1–0.01 m2 s?1 and 1–0.1 m2 s?1 for the bulk and fault zone scenarios, respectively). A permeability–depth decay model would have also satisfied the 5‐year time lag criterion. We also tested several injection management scenarios including redistributing injection volumes between various wells and lowering the total volume of injected fluids. Scenarios that reduced computed excess heads by over 50% within the crystalline basement resulted from reducing the total volume of reinjected fluids by a factor of 2 or more.  相似文献   

9.
Book reviews     
Robert Rinehart (ed.), Finland and the United States. Diplomatic Relations Through Seventy Years (Washington DC: 1993). Institute for the Study of Diplomacy, Georgetown University, 141 pp. ISBN 0–934742–63–4. USD 12.00.

Karl Molin, Omstridd neutralitet. Experternas kritik av svensk utrikespolitik 1948–1950 (Disputed neutrality. The experts’ criticism of Swedish foreign policy, 1948— 1950). (Stockholm: Tiden, 1991). 109 pp. ISBN 91–550–3808–5. SKR 150.00

Anders Berge, Flyktingpolitik i stormakts skugga. Sverige og de sovjetryska flyktingarna under andra världskriget (Refugee policies in the shadow of a great power. Sweden and the Soviet Russian refugees during World War II). Uppsala Multiethnic Papers 26. (Centre for Multiethnic Research, Uppsala University, Uppsala, 1992). III pp. ISBN 91–86624–07–5.

Már Jónsson, Blóoskömm á Íslandi 1270–1870 (Incest in Iceland, 1270–1870). (Reykjavík: Háskóli Íslands, Háskólaútgáfan, 1993). 311 pp. ISBN 9979–54–048–6.

Michael Bregnsbo, Gejstlighedens syn på sam fund og ?vrigked 1775–1800, belyst ved trykte pradikener og taler (The attitudes of the clergy to society and authorities 1775–1800, revealed by printed sermons and speeches). (Copenhagen: Den danske historiske Forening, 1992). 160+124 pp. ISBN 87–87462–31–1.

Pentti Laasonen &; Johannes Wallmann (eds), Der Pietismus in seiner europäischen und aussereuropäischen Ausstrahlung (Pietism in its European and extra‐european radiation) Suomen kirkkohistoriallisen seuran, toimituksia 157/ Veröffentlichungen der finnischen Gesellschaft für Kirchengeschichte, 157 (Helsinki, 1992). 240 pp. ISBN 951–9021–87–6.

Ole Feldbaek (ed.), Dansk Identitetshistorie (History of the Danish national identity), vols 1–4. (Copenhagen: C.A. Reitzel, 1991–92) 424 pp., 468 pp., 673 pp., 589 pp. ISBN 87–7421–696–1, DKR 1400 (all volumes). Summaries in English in vol. 4.

Conny Blom, Tiggare, tidstjuvar, lättingar och landstiykare. Studier αν attityder och vär‐deringar i skrån, stadgar,, ordningar och lagförslag gällande den of fentlia vården 1533–1664. (Lund: Lund University Press, 1992.) 271 pp.  相似文献   

10.
M. R. M. Brown  M. Liu 《Geofluids》2016,16(5):801-812
Utah is one of the top producers of oil and natural gas in the United States. Over the past 18 years, more than 4.2 billion gallons of wastewater from the petroleum industry has been injected into the Navajo Sandstone, Kayenta Formation, and Wingate Sandstone in Carbon and Emery Counties, central Utah, where seismicity has increased during the same period. Previous studies have attributed this seismicity to coal mining. Here, we present evidence for wastewater injection being a major cause of the increased seismicity. We show that, in the coal mining area, seismicity rate increased significantly 1–5 years following the wastewater injection, and the earthquakes, mostly with magnitudes <3.0, are concentrated in areas seismically active prior to the injection. Using simple analytical and numerical models, we show that the injection in central Utah can sufficiently raise pore pressure to trigger seismicity within 10–20 km of the injection wells, and the time needed for the diffusion of pore pressure may explain the observed lag of seismicity increase behind the commencement of injection. The b‐value of these earthquakes increased following the wastewater injection, which is consistent with these events being injection‐induced. We conclude that the marked increase in seismicity rate in central Utah is induced by both mining activity and wastewater injection, which raised pore pressure along preexisting faults.  相似文献   

11.
This article deals with the translations of Old French works completed at the court of Hákon Hákonarson, king of Norway. The first one was probably completed in 1226 and some 40 followed: translations of epic poems, courtly romances and lais, adventure romances and a fabliau. In all cases, we ought to speak of adaptations and not of word-for-word translations.

Together, these literary works form an outstanding corpus, elaborated mainly for didactical purposes and in order to support Hákon Hákonarson's project to build a monarchy à l'européenne. For that, some literary works were selected and – in their adaptations – some ethical and social values promoted while some others were not; and some great literary works were intentionally ignored and remained untranslated.  相似文献   

12.
The paper describes and analyses recent finds of the European pond turtle (Emys orbicularis) from the archaeological sites at Obříství (Mělník District, at the confluence of the Elbe and Moldau rivers in the Bohemian Basin, Czech Republic). Turtle remains were found in three sunken features dated to the Late Bronze Age or to the Hallstatt period, and in one feature dated to the Neolithic. The high number of osteological finds, particularly the number of individuals found in one place, is unique within Bohemia and very rare for the Bronze Age to Iron Age in Europe. A large number of shell remains were identified, from at least 12 individuals in feature 1480, and from at least 5 individuals in feature 1483. The high numbers support the hypothesis that the European pond turtle was once a regular feature of the local fauna, even though the Bohemian basin is surrounded by mountains, which will have presented difficulties for the process of postglacial recolonization by semiaquatic thermophilous reptiles. The findings from Obříství show evidence of the exploitation of turtles for food. Signs of culinary procedures and the human consumption of turtles include anthropogenic chop marks, signs of burning and the apparently intentional segmentation of the turtle bodies. The quantity of turtle bones is still negligible, however, compared with those of mammals. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

13.
Deformation and focused fluid flow within a mineralized system are critical in the genesis of hydrothermal ore deposits. Dilation and integrated fluid flux due to coupled deformation and fluid flow in simple strike–slip fault geometries were examined using finite difference analysis in three dimensions. A series of generic fault bend and fault jog geometries consistent with those seen in the western Mount Isa Inlier were modelled in order to understand how fault geometry parameters influence the dilation and integrated fluid flux. Fault dip, fault width, bend/jog angle, and length were varied, and a cross-cutting fault and contrasting rock types were included. The results demonstrate that low fault dips, the presence of contrasts in rock type, and wide faults produce highest dilation and integrated fluid flux values. Increasing fault bend lengths and angles increases dilation and integrated fluid flux, but increasing fault jog length or angle has the opposite effect. There is minimal difference between the outputs from the releasing and restraining fault bend and jog geometries. Model characteristics producing greater fluid flows and/or gradients can be used in a predictive capacity in order to focus exploration on regions with more favorable fault geometries, provided that the mineralized rocks had Mohr–Coulomb rheologies similar to the ones used in the models.  相似文献   

14.
Two single bovine burials and one mixed animal burial (containing bovine and canid skeletal remains) have been unearthed at two Baden culture sites, Aljmaš‐Podunavlje and Osijek‐Retfala located in Eastern Croatia. Zooarchaeological analysis attributed the faunal remains to domesticated cattle (Bos taurus) and in one case a dog (Canis familiaris). Almost complete and articulated skeletons of subadult or adult cows were found in all three examined features, while pit 59/60 from Aljmaš also contained a skull belonging to an adult‐domesticated cattle and a skeleton of a very young dog, 2–3 months old. All of the skeletons are well preserved and display no evidence of carcass processing indicating that the animals were buried intentionally. Consideration of the positions in which these animals were interred and their relationship with nearby deposits enables discussion of potential animal burial strategies and possible connections with certain ritual practices in which cows and in one case a dog played important roles. The described burials represent the southernmost known distribution of the rite discussed. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

15.
Structure‐ and tectonic‐related gas migration into Ordovician sandstone reservoirs and its impact on diagenesis history were reconstructed in two gas fields in the Sbaa Basin, in SW Algeria. This was accomplished by petrographical observations, fluid inclusion microthermometry and stable isotope geochemistry on quartz, dickite and carbonate cements and veins. Two successive phases of quartz cementation (CQ1 and CQ2) occurred in the reservoirs. Two phase aqueous inclusions show an increase in temperatures and salinities from the first CQ1 diagenetic phase toward CQ2 in both fields. Microthermometric data on gas inclusions in quartz veins reveal the presence of an average of 92 ± 5 mole% of CH4 considering a CH4‐CO2 system, which is similar to the present‐day gas composition in the reservoirs. The presence of primary methane inclusions in early quartz overgrowths and in quartz and calcite veins suggests that hydrocarbon migration into the reservoir occurred synchronically with early quartz cementation in the sandstones located near the contact with the Silurian gas source rock at 100–140°C during the Late Carboniferous period and the late Hercynian episode fracturing at temperatures between 117 and 185°C, which increased in the NW‐direction of the basin. During the fracture filling, three main types of fluids were identified with different salinities and formation temperatures. A supplementary phase of higher fluid temperature (up to 226°C) recorded in late quartz, and calcite veins is related to a Jurassic thermal event. The occurrence of dickite cements close to the Silurian base near the main fault areas in both fields is mainly correlated with the sandstones where the early gas was charged. It implies that dickite precipitation is related to acidic influx. Late carbonate cements and veins (calcite – siderite – ankerite and strontianite) occurred at the same depths resulting from the same groundwater precipitation. The absence of methane inclusions in calcite cements result from methane flushing by saline waters.  相似文献   

16.
Methane soil flux measurements have been made in 38 sites at the geothermal system of Sousaki (Greece) with the closed chamber method. Fluxes range from ?47.6 to 29 150 mg m?2 day?1, and the diffuse CH4 output of the system has been estimated at 19 t a?1. Contemporaneous CO2 flux measurements showed a moderate positive correlation between CO2 and CH4 fluxes. Comparison of the CO2/CH4 soil flux ratios with the CO2/CH4 ratio of the gases of the main gas manifestations provided evidence for methanotrophic activity within the soil. Laboratory CH4 consumption experiments confirmed the presence of methanotrophic microorganisms in soil samples collected at Sousaki. Consumption was generally in the range from ?4.9 to ?38.9 pmolCH4 h?1 g?1 but could sometimes reach extremely high values (?33 000 pmolCH4 h?1 g?1). These results are consistent with recent studies on other geothermal systems that revealed the existence of thermoacidophilic bacteria exerting methanotrophic activity in hot, acid soils, thereby reducing methane emissions to the atmosphere.  相似文献   

17.
Abstract

The article takes its point of departure in 12 Sámi sacrificial places from northern Sweden and Norway. It is argued that the sites with metal objects of the ninth to fourteenth centuries in a number of ways are comparable to acts of deposition in south Scandinavia. These Viking Age depositions consisted of partly the same types of artefacts, took place on the shores of wetlands with sacral names and were in use in the same time period as the Sámi sacrificial places. The similarities and differences between the two traditions are discussed, focusing on some possible links between aspects of animistic world views and biographical perspectives on artefacts. This opens up the possibility that not only the Sámi, but even the Old Norse world views contained elements of animistic perspectives. It is claimed that the two traditions reflect partially parallel ways of handling the landscape and dealing with objects among the Sámi of Øvre Norrland and the Norse population of south Scandinavia.  相似文献   

18.
In November and December 1979 the solar 10.7 cm radio flux density, sunspot number, X-ray flux and EUV flux were high and very variable. The day-to-day variations of noon F2-layer height and Elayer electron density at three ionosonde stations (Slough, Port Stanley and Huancayo) are found to be well correlated with the day-to-day variations of solar activity. The short-term E- and F-layer variations are consistent with those derived from longer-term studies.  相似文献   

19.
At the Dixie Valley geothermal field, Nevada, USA, fluid boiling triggered the precipitation of carbonate scale minerals in concentric bands around tubing inserted into production well 28–33. When the tubing was removed, this mineral scale was sampled at 44 depth intervals between the wellhead and 1227 m depth. These samples provide a unique opportunity to evaluate the effects of fluid boiling on the scale mineralogy and geochemistry of the vapor and liquid phase. In this study, the mineralogy of the scale deposits and the composition of the fluid inclusion gases trapped in the mineral scales were analyzed. The scale consists mainly of calcite from 670–1112 m depth and aragonite from 1125 to 1227 m depth, with traces of quartz and Mg‐smectite. Mineral textures, including hopper growth, twinning, and fibrous growth in the aragonite and banded deposits of fine grained calcite crystals, are the result of progressive boiling. The fluid inclusion noncondensable gas was dominated by CO2. However, significant variations in He relative to N2 and Ar provide evidence that the geothermal reservoir consists of mixed source deeply circulating reservoir water and shallow, air saturated meteoric water. Gas analyses for many inclusions also showed higher CH4 and H2 relative to CO2 than measured in gas sampled from this well, other production wells, and fumaroles. These inclusions are interpreted to have trapped CH4‐ and H2‐enriched gas resulting from early stages of boiling.  相似文献   

20.
M. Niwa  Y. Mizuochi  A. Tanase 《Geofluids》2015,15(3):387-409
In some cases, water–rock interactions in fault zones can affect radionuclide migration. Here, we analyzed the chemical compositions of well‐exposed fault rocks from the strike‐slip Atera Fault, Central Japan, in order to understand the variability and behavior of major and selected trace elements. The fault zone has a 1.2‐m‐wide, smectite‐rich fault core and paired damage zones that developed within welded tuff on one side of the core and within granite on the other side. The 30‐cm‐wide, kaolinite‐rich fault gouge is developed in granite cataclasite, and it shows indications of the latest fault activity, while the 1.2‐m‐wide fault core appears to be older. Hydrogen and oxygen isotope ratios in the clay‐rich fault gouges, and carbon and oxygen isotope ratios in carbonates indicate that the two major clay‐rich zones formed in bedrock near the surface, consistent with observed deformation structures. Based on chemical analyses, we identified (1) a slight depletion in SiO2, Na2O, K2O, and light rare earth elements at the edges of the 1.2‐m‐wide fault core, (2) a clear depletion in SiO2, Na2O, K2O, and all rare earth elements except Eu in the 30‐cm‐wide fault gouge, and (3) an increase in CaO, MnO, and heavy rare earth elements across the entire 1.2‐m‐wide fault core. Findings (1) and (2) reflect water–rock interactions in the 1.2‐m‐wide fault core and in the 30‐cm‐wide fault gouge that resulted in the formation of smectite and kaolinite. Finding (3) reflects carbonate precipitation caused by the addition of basalt fragments from a nearby site to the 1.2‐m‐wide fault core during faulting, and subsequent sorption reactions of heavy rare earth elements via processes such as complexation with the carbonates.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号