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排序方式: 共有678条查询结果,搜索用时 281 毫秒
101.
Helen Glenn Diana TingleySonia Sánchez Maroño Dennis HolmGurpreet Padda Ingi Runar EdvardssonAlexis Conides Kostas KapirisMintewab Bezabih Premachandra WattageSakari Kuikka 《Marine Policy》2012,36(1):54-72
This paper explores the issue of “trust” in the fisheries science community, a key corollary of effective risk communication. It presents the findings of a survey undertaken in Iceland, Greece, Spain, United Kingdom and Faroe Islands during 2008. The findings reveal differing levels of trust and mistrust in the fisheries science community between countries and between stakeholder groups, demonstrating areas for future attention in the interests of improving fisheries science and management. As this paper explores, unfortunately the “trust” necessary for effective stakeholder cooperation and participation within current fisheries science is currently somewhat lacking. The cited reasons behind this lack of trust include: a lack of soundness, credibility, responsiveness, flexibility and stakeholder involvement, flawed data and weak science, poor communications and political and lobby group interference. Notable from the results is a lack of consensus on the existence of a common language and vision. It is evident, however, that certain aspects of fisheries science are strong contributors to trust and that there are opportunities for improvement. 相似文献
102.
JOHN WESTERN 《Geographical review》2008,98(4):532-550
ABSTRACT. Over the past quarter‐century academic geographers have interrogated the concept of “scale.” It had previously been conceived as an unproblematic and mechanical item in geographical representation, a device for moving “up” from the finely detailed to the general. Regular, commonsensical steps were supposed to move one from the corporeal scale to the global scale, each scale nested into the next higher. Such is the “Russian‐dolls” mode, whereby an individual considering his or her geographical identity—as in this study—would proceed hierarchically in scale from self, to city, to region, to nation, to continent. Ethnographic evidence from Strasbourg, France, however, reveals another mode: “scale skipping.” Here an individual, musing upon her or his identity, can plausibly make the leap from the individual to the supranational scale in one sentence. Instructive examples of both modes are furnished from two fifteen‐strong groups of Strasburgers, selected for their presumed attachment to the supranational‐scale ideal of “Europe.” The older group comprises professional Eurocrats; the younger group, college students returning to complete their studies in Strasbourg after attending universities elsewhere in the European Union through the Erasmus Program of study abroad. 相似文献
103.
E. M. Cushing O. Bellier S. Nechtschein M. Sébrier A. Lomax Ph. Volant P. Dervin P. Guignard L. Bove 《Geophysical Journal International》2008,172(3):1163-1178
Assessing seismic hazard in continental interiors is difficult because these regions are characterized by low strain rates and may be struck by infrequent destructive earthquakes. In this paper, we provide an example showing that interpretations of seismic cross sections combined with other kinds of studies such as analysis of microseismicity allow the whole seismogenic source area to be imaged in this type of region. The Middle Durance Fault (MDF) is an 80-km-long fault system located southeastern France that has a moderate but regular seismicity and some palaeoseismic evidence for larger events. It behaves as an oblique ramp with a left-lateral-reverse fault slip and has a low strain rate. MDF is one of the rare slow active fault system monitored by a dedicated dense velocimetric short period network. This study showed a fault system segmented in map and cross section views which consists of staircase basement faults topped by listric faults ramping off Triassic evaporitic beds. Seismic sections allowed the construction of a 3-D structural model used for accurate location of microseismicity. Southern part of MDF is mainly active in the sedimentary cover. In its northern part and in Alpine foreland, seismicity deeper than 8 km was also recorded meaning active faults within the crust cannot be excluded. Seismogenic potential of MDF was roughly assessed. Resulting source sizes and estimated slip rates imply that the magnitude upper limit ranges from 6.0 to 6.5 with a return period of a few thousand years. The present study shows that the coupling between 3-D fault geometry imaging and accurate location of microseismicity provides a robust approach to analyse active fault sources and consequently a more refined seismic hazard assessment. 相似文献
104.
105.
The junction of the southeastern Guizhou, the southwestern Hunan, and the northern Guangxi regions is located within the southwestern Jiangnan orogen and forms a NE-trending ∼250 km gold belt containing more than 100 gold deposits and occurrences. The Pingqiu gold deposit is one of the numerous lode gold deposits in the southeastern Guizhou district. Gold mineralization is hosted in Neoproterozoic lower greenschist facies metamorphic rocks and controlled by fold-related structures. Vein types present at Pingqiu include bedding-parallel and discordant types, with saddle-reefs and their down limb extensions dominating but with lesser discordant types. The major sulfide minerals are arsenopyrite and pyrite, with minor sphalerite, galena, chalcopyrite, and rare pyrrhotite, marcasite, and tetrahedrite. Much of the gold is μm- to mm-sized grains, and occurs as fracture-controlled isolated grains or filaments in quartz, galena, sphalerite, pyrite, and wallrock.Three types of fluid inclusions are distinguished in hydrothermal minerals. Type 1 aqueous inclusions have homogenization temperatures of 171–396 °C and salinities of 1.4–9.8 wt% NaCl equiv. Type 2 aqueous-carbonic inclusions yield final homogenization temperatures of 187–350 °C, with salinities of 0.2–7.7 wt% NaCl equiv. Type 3 inclusions are carbonic inclusions with variable relative content of CO2 and CH4, and minor amounts of N2 and H2O. The close association of CO2-rich inclusions and H2O-rich inclusions in groups and along the same trail suggests the presence of fluid immiscibility. The calculated δ18OH2O values range from 4.3‰ to 8.3‰ and δDH2O values of fluid inclusions vary from −55.8‰ to −46.9‰. A metamorphic origin is preferred on the basis of geological background and analogies with other similar deposit types.Two ore-related sericite samples yield well-defined 40Ar/39Ar plateau ages of 425.7 ± 1.7 Ma and 425.2 ± 1.3 Ma, respectively. These data overlap the duration of the Caledonian gold mineralization along the Jiangnan orogen, and suggest that gold mineralization was post-peak regional metamorphism and occurred during the later stages of the Caledonian orogeny.Overall, the Pingqiu gold deposit displays many of the principal characteristics of the Bendigo gold mines in the western Lachlan Orogen (SE Australia) and the Dufferin gold deposit in the Meguma Terrane (Nova Scotia, Canada) but also some important differences, which may lead to the disparity in gold endowment. However, the structural make-up at deposit scale, and the shallow mining depth at present indicate that the Pingqiu gold deposit may have considerable gold potential at depth. 相似文献
106.
A new dinosaur sauropod from the Golmayo Formation (upper Hauterivian-lower Barremian) in Soria province (Spain) is described as Soriatitan golmayensis gen. et sp. nov. The new material consists of one tooth, three dorsal vertebrae with ribs, a partial sacrum, five caudal centra, two caudal vertebral spines, one chevron, a humerus, an ulna, a radius, two partial ilia, two ischia, a fragment of pubis, and a partial femur. Cladistic analysis identified the material as belonging to Brachiosaruidae within Titanosauriformes. Sauropod material from the Golmayo Formation shares a diagnostic feature with Abydosaurus, Cedarosaurus, Tastavinsaurus and Venenosaurus including anteriorly deflected anterior–middle caudal neural spines and with Cedarosaurus a proximodistally straight lateral margin between the proximal head and the shaft of the humerus. Eight characters are potential autapomorphies in the sauropod from Spain, including the presence of a large rectangular ventral ridge below the preacetabular process of the ilium, the same length of the pubic and ischiadic blades in the ischium, and two lateral ridges in the lateral area of the deltopectoral crest of the humerus. The presence of Early Cretaceous brachiosarids in both, North America and Europe, give support to the hypothesis of a connection between the tectonic plates of these continents at some point during the Early Cretaceous. 相似文献
107.
J. A. Webb 《Australian Journal of Earth Sciences》2017,64(7):841-850
The low-relief summit plateaus (high plains) of the Southeastern Highlands are remnants of a widespread peneplain that was initially uplifted in the mid-Cretaceous and reached its current elevation in the Miocene–Pliocene. There are two mutually exclusive scenarios for the origin of the high plains: an uplifted peneplain originally formed by long-term denudation through the Mesozoic and late Paleozoic, contrasting with creation by ~1.5 km of erosion following the mid-Cretaceous uplift (based on fission track data). The hypothesis of a Mesozoic peneplain is consistent with the low relief of the high plains, the ca 200 Ma available to form the peneplain, and the pre-late Mesozoic oxygen-isotope composition of secondary kaolinites in weathering profiles on the high plains. If the ca 30 Ma cooling event recorded by the fission track data is due to ~1.5 km of denudation, then the high plains peneplain formed in the Late Cretaceous–early Paleogene, close to sea-level, and was uplifted in the early Paleogene, because evidence from basalts and fossil floras shows that the high plains surface was moderately elevated in the Eocene. This scenario is difficult to reconcile with the long-term erosion necessary to form such an extensive peneplain, the lack of sedimentary evidence for early Paleogene uplift, and the relatively small reduction in elevation (~250 m) that would have resulted from ~1.5 km of erosion (because the crust in this area is in isostatic equilibrium). Furthermore, extensive Cretaceous–early Paleogene denudation should have removed the pre-late Mesozoic secondary kaolinites present in weathering profiles in the highlands. There is no evidence that the Mesozoic peneplain was buried by kilometres of sediment and then exhumed in the Cretaceous–early Paleogene. I therefore conclude that the high plains of the Southeastern Highlands are the remnants of a Mesozoic peneplain uplifted in the mid-Cretaceous and again in the Miocene–Pliocene. 相似文献
108.
Giampaolo Di Silvio Chiara Dall’Angelo Davide Bonaldo Giacomo Fasolato 《Continental Shelf Research》2010
This model is based on the concept of transport concentration, defined as the time-averaged concentration in a given location of a lagoon, which determines the long-term net transport of sediments as the sum of a dispersive and an advective flux. Dispersive net flux of sediments is due to the alternate components of the tidal flow, while the advective net flux of sediments is due to the residual (Eulerian) component of the tidal, fluvial and littoral flow and possibly to the asymmetry between flow and ebb tide. 相似文献
109.
110.
David “Jim” Nemeth 《The Professional geographer》2013,65(4):583-586
Why is Ortley Beach, New Jersey, known as Superstorm Sandy's ground zero? This article employs qualitative vulnerability analysis to understand why vulnerability of second homes in Ortley Beach resulted in dune failure and slow rebuilding after Sandy. The second-home owners who largely make up the community in Ortley Beach are identified as the key vulnerable group. This group's lack of political representation and financial compensation after Sandy increased house damage and slowed rebuilding. Identifying the level of vulnerability of the majority group in a location is paramount to understanding how the community recovers from a disaster. Such identification can also aid in preparing communities, especially for types of disasters they have not yet encountered. 相似文献