The Canary Islands fishing policy     

Carlos Angel Pérez Labajos  Beatriz Blanco Rojo  Rafael Mazas Arranz 《Marine Policy》1996,20(6):463-474

In the last 20 years the Canary Islands fishing fleet has gone from the privileged position of enjoying abundant catches in the old “Canary Islands-Saharan” fishing grounds to the precarious situation in which it currently finds itself. This paper aims to determine what the future holds for The Canaries fishing sector. Hence, fishing rights and policies are analysed and the special aids received from the EC are compared with those applied in other similar ultraperipheric regions. The adoption of a more interventionist role by the Canary Islands administration may solve at least part of the problem faced by this sector.  相似文献   

Coastal uplift rate at Matanzas (Cuba) inferred from MIS5e phreatic overgrowths on speleothems          下载免费PDF全文

Jo De Waele  Ilenia M. D'Angeli  Nicola Tisato  Paola Tuccimei  Michele Soligo  Joaquín Ginés  Angel Ginés  Joan J. Fornós  Igor M. Villa  Esteban R. Grau González  Stefano M. Bernasconi  Tomaso R. R. Bontognali 《地学学报》2017,29(2):98-105

Many morphological elements in Cuba's landscape (e.g. marine terraces, tidal notches) demonstrate that coastal uplift has taken place, but the rate at which this occurs is not known. Carbonate phreatic overgrowths on speleothems have been found in a cave in Central North Cuba, ~1 km from the present coastline at 16 m asl. They form exceptional and unique mushroom‐shaped speleothems and balconies decorating the walls of the rooms. These phreatic overgrowths on speleothems (POS) formed at the oscillating air–water interface in sea‐level controlled anchialine lakes. U/Th dating of these overgrowths suggests ages that are compatible with the Marine Isotope Stage 5e (i.e. 130–115 ka). These POS have fixed this sea‐level highstand and demonstrate that this part of Cuba has been subjected to a much lower uplift rate than previously reported, that is, less than 0.1 mm/year since the last interglacial.  相似文献   

Sub‐millennial climate shifts in the western Mediterranean during the last glacial period recorded in a speleothem from Mallorca,Spain     

Edward J. Hodge  David A. Richards  Peter L. Smart  Angel Gins  David P. Mattey 《第四纪科学杂志》2008,23(8):713-718

Very few high‐resolution and directly dated terrestrial archives of the last glacial period exist for the western Mediterranean region, yet this is a key locality for recording sub‐millennial North Atlantic and Mediterranean climate change. Here, we present evidence of effective precipitation changes based on growth history and δ¹³C of calcite in a Mallorcan stalagmite that grew between 112 and 48 ka. Effective precipitation in Mallorca appears to have been sensitive to proximal sea surface temperature variations and at certain times, ca. 76 ka for example, changed rapidly from moist to arid conditions in only a few centuries. A sea‐level highstand during Marine Isotope Stage (MIS) 5a interrupted growth. Regrowth started promptly after this, but effective precipitation decreased markedly for much of the later part of MIS 5a, and also for shorter periods correlative with Heinrich events H8 (ca. 90 ka) and H6 (ca. 65 ka), with growth ceasing during H5 (ca. 48 ka). Arid episodes in Mallorca appear to be expressions of extremely cold periods recorded further north in Europe and occur contemporaneously with rapid decreases in Greenland temperature. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Historical reconstruction and evolution of the large landslide of Inza (Navarra,Spain)     

de Ojeda  P. Sanz  Sanz  E.  Galindo  R. 《Natural Hazards》2021,109(3):2095-2126

Natural Hazards - In the winter of 1714–1715, a large rotational landslide originated on the northern slope of the Sierra de Aralar (Navarra, Spain), generating an earthflow that slowly...  相似文献   

What does 'good ecological potential' mean, within the European Water Framework Directive?     

Borja A  Elliott M 《Marine pollution bulletin》2007,54(10):1559-1564

The most important objective within the European Water Framework Directive (WFD) is to achieve a ‘good ecological status’ (GES) for all waters, by 2015. Some methodologies have been developed for assessing GES within natural water bodies, in which the ecological status is a perceived or measured deviation from a reference condition. However, the WFD also consider ‘Heavily modified water bodies’ (HMWB) (a water body resulted from physical alterations by human activity, which substantially change its hydrogeomorphological character, e.g. a harbour). In implementing the WFD, environmental managers are required to assess the status of HMWBs in terms of achieving ‘Good Ecological Potential’ (GEP). This contribution defines and studies GEP from an ecological point of view, taking into account some ecological restoration principles. Finally, this contribution gives some guidance on how establish GEP, using as example a harbour within the North East Atlantic.  相似文献   

Observations of Comet 9P/Tempel 1 around the Deep Impact event by the OSIRIS cameras onboard Rosetta     

Horst Uwe Keller  Sonia Fornasier  Stubbe F. Hviid  Jörg Knollenberg  Miriam Rengel  Gabriele Cremonese  Detlef Koschny  Ekkehard Kührt  Holger Sierks  Cesare Barbieri  Hans Rickman  Michael F. A'Hearn  Maria-Antonella Barucci  Vania da Deppo  Björn J.R. Davidsson  Stefano Debei  Fritz Gliem  José J. Lopez Moreno  Giampiero Naletto  Angel Sanz Andrés 《Icarus》2007,187(1):87-103

The OSIRIS cameras on the Rosetta spacecraft observed Comet 9P/Tempel 1 from 5 days before to 10 days after it was hit by the Deep Impact projectile. The Narrow Angle Camera (NAC) monitored the cometary dust in 5 different filters. The Wide Angle Camera (WAC) observed through filters sensitive to emissions from OH, CN, Na, and OI together with the associated continuum. Before and after the impact the comet showed regular variations in intensity. The period of the brightness changes is consistent with the rotation period of Tempel 1. The overall brightness of Tempel 1 decreased by about 10% during the OSIRIS observations. The analysis of the impact ejecta shows that no new permanent coma structures were created by the impact. Most of the material moved with . Much of it left the comet in the form of icy grains which sublimated and fragmented within the first hour after the impact. The light curve of the comet after the impact and the amount of material leaving the comet ( of water ice and a presumably larger amount of dust) suggest that the impact ejecta were quickly accelerated by collisions with gas molecules. Therefore, the motion of the bulk of the ejecta cannot be described by ballistic trajectories, and the validity of determinations of the density and tensile strength of the nucleus of Tempel 1 with models using ballistic ejection of particles is uncertain.  相似文献   

The effect of the "Prestige" oil spill on the plankton of the N-NW Spanish coast     

Varela M  Bode A  Lorenzo J  Alvarez-Ossorio MT  Miranda A  Patrocinio T  Anadón R  Viesca L  Rodríguez N  Valdés L  Cabal J  Urrutia A  García-Soto C  Rodríguez M  Alvarez-Salgado XA  Groom S 《Marine pollution bulletin》2006,53(5-7):272-286

Chlorophyll, primary production, zooplankton biomass and the species composition of phytoplankton and zooplankton were studied in 2003, after the Prestige shipwreck. The information obtained was compared to previous data series available for the area affected by the spill. A large data series on plankton variables for the N-NW Spanish coast existed, and therefore a realistic evaluation of the effects by comparison with the range of natural variability could be carried out. We emphasized the evaluation of impact during the spring bloom, the first important biological event after the spill. Some minor changes were observed occasionally, but they did not show any clear pattern and were more related to the natural variability of the ecosystem than to effect of the spill. Plankton community structure did not undergo any changes. Only a few species were more abundant during spring 2003 than in previous years. No significant changes were detected in the planktonic community during productive periods, such as the spring bloom and the summer blooms related to intrusions of East North Atlantic Central Waters. The lack of evidence of the effects of the spill on planktonic communities is discussed in terms of the characteristics of the fuel, the high dynamics of the water masses, the biological mechanisms through which the fuel from the surface waters is transferred to the sea floor and, particularly, the influence of the natural variability by means of large and meso-scale hydrographic processes in the area under study. At the present time it is not possible to determine any minor effects the spill may have had on the plankton owing to the great variability of the planktonic cycles and the short-term impact of the oil from the Prestige on the pelagic system.  相似文献   

Daily scale modelling of aquifer–river connectivity in the urban alluvial aquifer in Langreo, Spain     

Pedro Martínez-Santos  Pedro E. Martínez-Alfaro  Eugenio Sanz  Angel Galindo 《Hydrogeology Journal》2010,18(6):1525-1537

Evaluating aquifer–river interactions is naturally complex, particularly within urban settings. This is largely due to the difficulties involved in quantifying most elements of the water balance. The ability of numerical models to deal with several dynamic variables simultaneously makes them valuable tools to address this kind of problem. An applied, modeling-based approach to investigate the spatial and temporal variations of aquifer–river connectivity within a shallow urban aquifer is presented. Model development is based on comprehensive field campaigns in Langreo, Spain. Two calibration runs (for summer and winter conditions) were carried out in order to evaluate the spatial distribution of recharge rates. The model suggests that baseflows are largely negligible in comparison with total streamflows. This is mostly attributed to the abrupt nature of the catchment, which prevents the existence of sufficiently large alluvial systems to a great extent. Modelling results also show that aquifer–river connectivity at the study site is constrained by urban pumping as well as by seasonal fluctuations.  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   

The Western Sierras Pampeanas: Protracted Grenville-age history (1330–1030 Ma) of intra-oceanic arcs,subduction–accretion at continental-edge and AMCG intraplate magmatism     

C.W. Rapela  R.J. Pankhurst  C. Casquet  E. Baldo  C. Galindo  C.M. Fanning  J.M. Dahlquist 《Journal of South American Earth Sciences》2010,29(1):105-127

New U–Pb SHRIMP zircon ages combined with geochemical and isotope investigation in the Sierra de Maz and Sierra de Pie de Palo and a xenolith of the Precordillera basement (Ullún), provides insight into the identification of major Grenville-age tectonomagmatic events and their timing in the Western Sierras Pampeanas. The study reveals two contrasting scenarios that evolved separately during the 300 Ma long history: Sierra de Maz, which was always part of a continental crust, and the juvenile oceanic arc and back-arc sector of Sierra de Pie de Palo and Ullún. The oldest rocks are the Andino-type granitic orthogneisses of Sierra de Maz (1330–1260 Ma) and associated subalkaline basic rocks, that were part of an active continental margin developed in a Paleoproterozoic crust. Amphibolite facies metamorphism affected the orthogneisses at ca. 1175 Ma, while granulite facies was attained in neighbouring meta-sediments and basic granulites. Interruption of continental-edge magmatism and high-grade metamorphism is interpreted as related to an arc–continental collision dated by zircon overgrowths at 1170–1230 Ma. The next event consisted of massif-type anorthosites and related meta-jotunites, meta-mangerites (1092 ± 6 Ma) and meta-granites (1086 ± 10 Ma) that define an AMCG complex in Sierra de Maz. The emplacement of these mantle-derived magmas during an extensional episode produced a widespread thermal overprint at ca. 1095 Ma in neighbouring country rocks. In constrast, juvenile oceanic arc and back-arc complexes dominated the Sierra de Pie de Palo–Ullún sector, that was fully developed ca. 1200 Ma (1196 ± 8 Ma metagabbro). A new episode of oceanic arc magmatism at ～1165 Ma was roughly coeval with the amphibolite high-grade metamorphism of Sierra de Maz, indicating that these two sectors underwent independent geodynamic scenarios at this age. Two more episodes of arc subduction are registered in the Pie de Palo–Ullún sector: (i) 1110 ± 10 Ma orthogneisses and basic amphibolites with geochemical fingerprints of emplacement in a more mature crust, and (ii) a 1027 ± 17 Ma TTG juvenile suite, which is the youngest Grenville-age magmatic event registered in the Western Sierras Pampeanas. The geodynamic history in both study areas reveals a complex orogenic evolution, dominated by convergent tectonics and accretion of juvenile oceanic arcs to the continent.  相似文献