The Chan Hol cave near Tulum (Quintana Roo,Mexico): evidence for long‐lasting human presence during the early to middle Holocene          下载免费PDF全文

Fabio Hering  Wolfgang Stinnesbeck  Jens Folmeister  Eberhard Frey  Sarah Stinnesbeck  Jerónimo Avilés  Eugenio Aceves Núñez  Arturo González  Alejandro Terrazas Mata  Martha Elena Benavente  Carmen Rojas  Adriana Velázquez Morlet  Norbert Frank  Patrick Zell  Julia Becker 《第四纪科学杂志》2018,33(4):444-454

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Factors controlling the vegetation distribution and coal‐forming environments in a strike‐slip basin. The Pennsylvanian Peñarroya‐Belmez‐Espiel Basin,southern Spain          下载免费PDF全文

Felipe González  Carmen Moreno  Erica Lorenzo  Gonzalo Márquez 《地学学报》2016,28(3):171-180

Coal‐forming environments require humid to perhumid conditions. Tectonics governs the size, location and availability of coal seams developed in such environments. While large Pennsylvanian paralic basins generated thick and continuous coal seams, many other small coeval basins, which were tectonically active, developed a puzzling succession, with carbonaceous deposits that varied in size, thickness and the nature of the coal‐forming flora. This study, conducted in the Peñarroya‐Belmez‐Espiel coalfield, a Variscan strike‐slip basin in the south of Spain, provides insights into this subject. The coal seams analysed, generated in different depositional environments, have quantitatively different palynological assemblages. Lacustrine coals are dominated by lycopsids; distal alluvial plain/marginal lacustrine coals are dominated by sphenophytes and tree ferns, and middle alluvial fan coals are dominated by sphenophytes, tree ferns and lycopsids. This means that when conditions were favourable for peat accumulation, peat accumulated regardless of the nature of the available flora.  相似文献   

Long-term study of at-sea distribution of seabirds and marine mammals in the Scotia Sea,Antarctica     

Jos Luis Orgeira  Mariela del Carmen Alderete  Yohana Gisell Jimnez  Juan Cruz Gonzlez 《极地研究(英文版)》2015,(2)

The Scotia Sea is one of the most biologically rich regions of Antarctica, and it hosts a large community of upper trophic-level predators. Long-term at-sea monitoring provides valuable information on ...  相似文献   

The severe zonda wind event of 11 July 2006 east of the Andes Cordillera (Argentine): a case study using the BRAMS model     

Federico Augusto Norte  Ana Graciela Ulke  Silvia Carmen Simonelli  Maximiliano Viale 《Meteorology and Atmospheric Physics》2008,102(1-2):1-14

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A less disastrous disaster: Managing response to climate-driven hazards in the Cayman Islands and NE Brazil     

Emma L. Tompkins  Maria Carmen Lemos  Emily Boyd 《Global Environmental Change》2008,18(4):736

This paper explores the relationship between disaster risk reduction and long-term adaptive capacity building in two climate vulnerable areas—the Cayman Islands in the Caribbean and Ceará, in NE Brazil. Drawing on past applications of the disaster risk reduction framework, we identify four critical factors that have led to reductions in risk: flexible, learning-based, responsive governance; committed, reform-minded and politically active actors; disaster risk reduction integrated into other social and economic policy processes; and a long-term commitment to managing risk. We find that while the presence of these factors has reduced overall risk in both regions, in Ceará, disaster response as it is currently practiced, has fallen short of addressing the fundamental causes of vulnerability that leave those prone to hazards able to cope in the short term, yet enmeshed in poverty and at risk from the longer-term changes associated with climate change. Although calls for integration of disaster risk management with poverty eradication are not new, there has been insufficient attention paid in the literature on how to foster such integration. Based on the two case studies, we argue that the adoption of good governance mechanisms (such as stakeholder participation, access to knowledge, accountability and transparency) in disaster risk reduction policy may create the policy environment that is conducive to the kind of structural reform needed to build long-term adaptive capacity to climate-driven impacts. We conclude that without a synergistic two-tiered approach that includes both disaster risk reduction and structural reform, disaster risk reduction, in the face of climate changes, will prove to be an expensive and ineffective palliative treatment of changing risks.  相似文献   

Andalusite and Na- and Li-rich cordierite in the La Costa pluton, Sierras Pampeanas, Argentina: textural and chemical evidence for a magmatic origin     

Pablo H. Alasino  Juan A. Dahlquist  Carmen Galindo  Cesar Casquet  Julio Saavedra 《International Journal of Earth Sciences》2010,99(5):1051-1065

The La Costa pluton in the Sierra de Velasco (NW Argentina) consists of S-type granitoids that can be grouped into three igneous facies: the alkali-rich Santa Cruz facies (SCF, SiO₂ ~67 wt%) distinguished by the presence of andalusite and Na- and Li-rich cordierite (Na₂O = 1.55–1.77 wt% and Li₂O = 0.14–0.66 wt%), the Anillaco facies (SiO₂ ~74 wt%) with a significant proportion of Mn-rich garnet, and the Anjullón facies (SiO₂ ~75 wt%) with abundant albitic plagioclase. The petrography, mineral chemistry and whole-rock geochemistry of the SCF are compatible with magmatic crystallization of Na- and Li-rich cordierite, andalusite and muscovite from the peraluminous magma under moderate P–T conditions (~1.9 kbar and ca. 735°C). The high Li content of cordierite in the SCF is unusual for granitic rocks of intermediate composition.  相似文献   

Time series of multivariate data in aquatic ecology     

Miguel Alvarez Cobelas  María Verdugo  Carmen Rojo 《Aquatic Sciences - Research Across Boundaries》1995,57(3):185-198

Coupling of multivariate methods and time series analysis can be ueful for studying dynamics of aquatic communities. This is demonstratred with a data set from the pelagic area of an oligo-mesotrophic lake in Central Spain during 61 consecutive days of Autumn overturn. Abiotic variables, phytoplankton species and their total biomass were traced. Species abundance and specific biomass were considered as indices of community structure and resource partitioning, respectively. Abiotic and algal data sets were subjected to factor analyses of cases separately. Atmospheric forcing and nitrogen could be considered as the main (2) driving variables of the abiotic matrix. The coupling of motile abilities and cell size was associated to the main factors of the community structure matrix whereas phosphorus limitation and species responses to buoyancy represented the main factors of the biomass matrix. Coordinates of the two first factors could be used to mimic the trajectories in the data space. Significant short term lags (1–4 days) were found in most time series. Lagged responses of atmospheric forcing and nitrogen on phytoplankton community structure and resource partitioning at scales of 1–7 days were also shown. Overall phytoplankton biomass did not show significant delayed responses, thereby suggesting that it might be resulting from the interplay of other non-studied factors.  相似文献   

Station Correction of the seismic station Kašperské Hory for short-periodP waves     

Carmen Sobotová  Jiří Vaněk  Reviewer K. Pěč 《Studia Geophysica et Geodaetica》1973,17(3):260-261

Summary The magnitude station correction of the seismic station Kaperské Hory, related to Prhonice, was determined for the vertical component of short-period P waves.  相似文献   

Wirkungen elektrischer Felder und Strahlungen atmosphärischen und kosmischen Ursprungs auf das Wasser     

Carmen Boute 《Theoretical and Applied Climatology》1955,7(1):146-155

Ohne ZusammenfassungMit 6 Textabbildungen  相似文献   

Hydraulics of recirculating well pairs for ground water remediation   总被引：1，自引：0，他引：1  

Cunningham JA  Hoelen TP  Hopkins GD  Lebrón CA  Reinhard M 《Ground water》2004,42(6-7):880-889

Recirculating well pairs are a proven means of implementing bioremediation and may also be useful for applying other in situ ground water remediation technologies. A bromide tracer test was performed to characterize the hydraulic performance of a recirculating well pair installed at Moffett Field, California. In particular, we estimate two important properties of the recirculating well pair: (1) the fraction of captured water that is recycled between the wells, and (2) the travel-time distribution of ground water in the induced zone of recirculation. We also develop theoretical estimates of these two properties and demonstrate they depend upon a dimensionless pumping rate, denoted xi. The bromide breakthrough curve predicted from theory agrees well with that determined experimentally at Moffett Field. The minimum travel time between the wells is denoted t(min). In theory, t(min) depends inversely on Q, the pumping rate in the recirculating wells, and is proportional to a2, the square of the distance between the wells. Both the experimental and theoretical travel-time distributions indicate that at least half the recirculating water travels between the wells along fast flowpaths (travel time < 2*t(min)). Therefore, when designing recirculating well pairs, engineers should ensure that t(min) will be sufficiently high to allow biologically mediated reactions (or other in situ remediation processes) sufficient time to proceed.  相似文献