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81.
M. J. Rodríguez-Peces J. García-Mayordomo J. M. Azañón A. Jabaloy 《Environmental Earth Sciences》2014,72(7):2423-2435
Complete rupture of the Padul Fault represents one of the largest plausible earthquakes in the Sierra Nevada Range, one of the most seismically active regions of Spain. We performed a regional assessment of earthquake-triggered slope instabilities in the western part of the range to determine the most likely types of failures from such an earthquake in the region and suggest where such failures have a higher likelihood of occurring. These results are broadly useful for management of regional life-lines and future development. First, a slope-instability inventory of the Sierra Nevada was produced to identify the most common instability types. Subsequently, the Newmark’s sliding rigid-block methodology, implemented in a geographic information system, was used to obtain the distribution of Newmark displacements in the area considering a M w 6.6 earthquake on the Padul Fault. The Newmark displacements were then compared to the distribution of the inventoried slope instabilities to identify the areas where seismicity could reactivate old slope instabilities or generate new ones, and to identify the involved landslide typology. The most likely seismically induced slope instabilities in the Sierra Nevada are rock falls and rock slides. These types of instabilities could be triggered by Newmark displacements of 2 cm or less. 相似文献
82.
Józef Żychowski 《Environmental Earth Sciences》2011,64(2):437-448
The investigations were carried out to identify processes and mineral products in the diversified subsoil sediments of mass
graves from WW1 (four graves) and 2 (five graves) and their surroundings, as well as the relations between the development
of sediments within the mass graves and the scale of migration of the products of corpse decomposition. The author studied
the role of iron compounds and clay minerals in the decomposition of human corpses buried in mass graves, followed by the
migration of selected elements. In particular, he concentrated on the list of elements found in the diversified sediments
of nine mass graves from SE Poland and to their relationship with phosphorus compounds. The methods applied included scanning
electron microscopy (SEM) and optical polarizing microscopy. Samples were collected from various depths in trenches and holes
dug in the vicinity of the graves, the sediments from the burial horizon and, when possible, the sediments underlying the
grave (studied downslope). Detected phosphorus occurs as a weakly crystalline compound in silt-rich sediments with relatively
stable water conditions. In silt-rich sediments with relatively stable moisture content, phosphorus occurs as a weakly crystalline
compound. More stable aggregates of decomposition products have been found on quartz grains covered with clay-ferruginous
rims. Fragments of human soft tissue were found only in those graves from WW2. There is no link between the spectrum of elements
in the sediments of the graves and the period of burials. The decomposition products that form depend primarily on the type
of sediments in which the mass graves were dug and, secondarily, although related, on the moisture content of the sediments.
It has been found that stabilization of decomposition products in situ is related to the presence of iron compounds and clay
minerals, particularly in finer-grained, aleuritic–pelitic sediments. 相似文献
83.
Matúš Hyžný Carlos S. Melo Ricardo S. Ramalho Ricardo Cordeiro Patrícia Madeira Lara Baptista A. Cristina Rebelo Cynthia Gómez Alfred Uchman Markes E. Johnson Björn Berning Sérgio P. Ávila 《第四纪科学杂志》2021,36(1):91-109
The presence of decapod crustaceans in the Pliocene and Pleistocene (MIS 5e) fossil record of Santa Maria Island (Azores Archipelago) is herein reviewed. Our study raises the number of fossil decapods from this island from one species to 10 taxa (three for the Pliocene and seven for the Last Interglacial). Four of these 10 taxa are reported for the first time in the fossil record, worldwide. A new species of a mud shrimp is also described (Upogebia azorensis n. sp.). Our study suggests that the Plio–Pleistocene decapod assemblages of the Azores did not differ significantly from modern ones, being dominated by species that are today widespread across the Webbnesia ecoregion, the Mediterranean Sea, and the eastern Atlantic shores, including the Azores. As far as can be judged from the limited fossil record, apparently no tropical crab species with a Cabo Verdean/Senegalese provenance reached the Azores during windows of opportunity associated with Glacial Termination 2 or with the initial setting of the Last Interglacial period. This contribution increases the total number of marine taxa reported for the Pliocene and Pleistocene outcrops of Santa Maria Island to 218 and 155, respectively, highlighting the scientific relevance of its palaeontological heritage. 相似文献
84.
Taphonomic analysis of small mammal bone remains preyed upon by wildcats (Carnivora: Felidae) from the central Monte Desert (Mendoza,Argentina) 下载免费PDF全文
José Manuel López María I. Rosi Solana Tabeni Benjamín Bender Horacio Chiavazza 《Boreas: An International Journal of Quaternary Research》2017,46(2):282-293
The present study analysed the taphonomic characteristics of small mammal bone accumulations produced by small felids in an area from the central Monte Desert (Mendoza, Argentina). In order to provide criteria to identify the role that these predators had in the formation of zooarchaeological assemblages, the anatomical representation, bone breakage patterns and degrees of digestive corrosion were evaluated. The main taphonomic results are: low average values for the relative abundance of skeletal elements; greater representation of mandibles, maxillae, isolated incisors, humeri and femora than the remaining elements; preponderance of cranial elements with high proportion of isolated teeth; elevated frequencies of proximal limb bones compared with distal parts; high degree of breakage in all skeletal elements and digestive corrosion on almost all diagnostic bones (mainly moderate and heavy). The values of the studied taphonomic variables indicate that small felids in this area made severe alterations to the bones of their prey (mainly rodents), attributable to the category of extreme modifier, while preserving enough skeletal elements to allow their taphonomic characterization. Tooth marks or grooves on bone surfaces produced by scratching and chewing were not detected. The low relative abundance of skeletal elements, the high degree of breakage and the elevated frequency of elements with digestion traces represent general taphonomic patterns that fall within those reported for other South American small carnivores. 相似文献
85.
Extreme-temperature events have a great impact on human society. Thus, knowledge of summer temperatures can be very useful both for the general public and for organizations whose workers operate in the open. An accurate forecasting of summer maximum and minimum temperatures could help to predict heatwave conditions and permit the implementation of strategies aimed at minimizing the negative effects that high temperatures have on human health. The objective of this work is to evaluate the skill of the regional atmospheric and modelling system (RAMS) model in determining daily summer maximum and minimum temperatures in the Valencia Region. For this, we have used the real-time configuration of this model currently running at the Centro de Estudios Ambientales de Mediterráneo Foundation. This operational system is run twice a day, and both runs have a 3-day forecast range. To carry out the verification of the model in this work, the information generated by the system has been broken into individual simulation days for a specific daily run of the model. Moreover, we have analysed the summer forecast period from 1 June to 31 August for 2007, 2008, 2009 and 2010. The results indicate good agreement between observed and simulated maximum temperatures, with RMSE in general near 2 °C both for coastal and inland stations. For this parameter, the model shows a negative bias around ?1.5 °C in the coast, while the opposite trend is observed inland. In addition, RAMS also shows good results in forecasting minimum temperatures for coastal locations, with bias lower than 1 °C and RMSE below 2 °C. However, the model presents some difficulties for this parameter inland, where bias higher than 3 °C and RMSE of about 4 °C have been found. Besides, there is little difference in both temperatures forecasted within the two daily RAMS cycles and that RAMS is very stable in maintaining the forecast performance at least for three forecast days. 相似文献
86.
Stefán Arnórsson Einar Gunnlaugsson Hördur Svavarsson 《Geochimica et cosmochimica acta》1983,47(3):567-577
New data from geothermal wells in Iceland have permitted empirical calibration of the chalcedony and geothermometers in the range of 25–180°C and 25–250°C respectively. The temperature functions are: Concentrations are expressed in ppm. These temperature functions correspond well with the chalcedony solubility data of Fournier (1973) and the thermodynamic data for low-albite/microcline/solution equilibria of Heloeson (1969).A new CO2 geothermometer is proposed which is considered to be useful in estimating underground temperatures in fumarolic geothermal fields. Its application involves analysis of CO2 concentrations in the fumarole steam. The temperature function which applies in the range 180?300°C is: logCO2 = 37.43 + 73192/T- 11829· 103/T2 + 0.18923T- 86.187·logT where T is in °K and CO2 in moles per kg of steam. 相似文献
87.
Molybdenum concentrations in Icelandic geothermal waters lie in the range 1–70 ppb. Warm waters and dilute high-temperature waters which contain high concentrations of sulphide are lowest in molybdenum. No correlation is otherwise observed between molybdenum concentrations and temperature. Surface waters and cold ground waters do not contain detectable molybdenum (<1 ppb). It seems likely that leaching rate is the prime factor in limiting molybdenum levels in these waters. Within individual geothermal fields molybdenum concentrations are either approximately constant or they vary regularly across the field. This regular variation may often be correlated with variations in other solute concentrations and subsurface temperatures and is taken to indicate a control of molybdenum mobility by a temperature dependent equilibrium. The evidence suggests that the solubility of molybdenite is responsible. Molybdenite has not been found in active geothermal systems in Iceland but is known to occur in some New Zealand geothermal systems and it has been identified in hydrothermally altered Tertiary basalt formations at Reydarártindur in southeast Iceland. Boiling and mixing with cold water leads to molybdenite undersaturation and thus these processes favour leaching of molybdenum from the rock. On the other hand, conductive cooling leads to supersaturation which favours removal of molybdenum from solution. 相似文献
88.
S. Panic V. Guzsvány Z. Kónya Á. Kukovecz G. Boskovic 《International Journal of Environmental Science and Technology》2017,14(6):1297-1306
Because of their high adsorption capacity, carbon nanotubes have caught the attention of the scientific community and a number of experimental results confirmed their ability to adsorb many toxins from water. The aim of this work was to study the kinetics, equilibrium and thermodynamics of thiamethoxam adsorption by multi-walled carbon nanotubes in aqueous solutions. To further elucidate the influence of nanotube structure on the adsorption mechanism, the experiments were performed on both fresh (pristine) and nitric acid-modified multi-walled carbon nanotubes. The results of the kinetic studies were analyzed using three kinetic models, while the adsorption equilibrium was tested against four different adsorption models. Based on the results, and the physico-chemical properties of the adsorbent and adsorbate, it is proposed that the dominant mechanism for thiamethoxam molecules attaching to multi-walled carbon nanotubes is caused by aromatic π–π interactions (electron donor–acceptor interactions). The results of thermodynamic calculations based on the adsorption data indicate the exothermic nature of the process, regardless of the carbon nanotube type used. The decrease in entropy and the consequent negative change in Gibbs free energy, as expected, confirm the spontaneity of thiamethoxam adsorption on both pristine and functionalized multi-walled carbon nanotubes. 相似文献
89.
Analysis of Mississippian coral assemblages from the Khenifra region of Central Morocco together with data from foraminiferal/algal microfossils has established new age dating of 5 localities within the Azrou–Khenifra Basin: Souk El Had and Sidi Lamine, where corals occur mainly in biostromes protected by oolitic shoals, Tabainout, where corals have been recorded in different environments related to microbial mounds, Alhajra Almatkouba, where corals occur in biostromal reworked beds and Tiouinine, where corals occur in a well structured, fringing reef. This study demonstrates the presence of richer more diverse coral assemblages than previously recorded, in a variety of environmental settings. These coral assemblages strengthen correlations with the Adarouch area in the NE part of the Azrou–Khenifra Basin. It is emphasised that in the upper Viséan there are close similarities with rugose coral assemblages in other parts of the Western Palaeotethys including North Africa, SW Spain and NW Europe, and that all belong to the same biogeographic province. 相似文献
90.
Ana Moreno Blas L. Valero‐Garcés Montserrat Jiménez‐Sánchez María José Domínguez‐Cuesta M. Pilar Mata Ana Navas Penélope González‐Sampériz Heather Stoll Pedro Farias Mario Morellón J. Pablo Corella Mayte Rico 《第四纪科学杂志》2010,25(7):1076-1091
A sedimentological and geochemical study of the Lago Enol sequence (Cantabrian Mountains, northern Spain), together with detailed geomorphological mapping, provides a first record of glacier evolution and climate change over the last 40 ka in the Picos de Europa National Park. The Enol glacier retreated from its maximum extent prior to 40 ka BP as demonstrated by the onset of proglacial lacustrine sedimentation in two glaciated depressions: the Comella hollow to the north (before 40 ka BP) and the Lago Enol (before 38 ka BP). These results support previous evidence that the maximum extent of southern European glaciers occurred earlier than in northern Europe. Alternation of homogeneous and laminated proglacial sediments during the glacier retreat illustrate a dynamic glacial evolution during the Marine Isotope Stage (MIS) 3 (40–26 ka BP). A slight warming is detected at 26 ka ago with the change from proglacial sediments (in a lake located in contact to the glacier) to glaciolacustrine sedimentation (in a non‐contact or distal lake). Finally, the onset of organic‐rich sediments took place at 18 ka ago. This last transition occurred in two phases, similarly to the North Atlantic Last Termination, suggesting a link between North Atlantic Deep Water formation oscillations and palaeohydrological variability in the Cantabrian Mountains. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献