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511.
This paper contributes to recent debates about whether urban policy discourses are transferable and what is at stake in their translation. It draws on discussion of Darwin (Northwest Territory, Australia), a tropical savanna location that the local government wants to promote as a 'creative city', without quite knowing what this might require. We discuss relevant debates on research knowledge construction, the creative city and the path-dependent character of neoliberal governmental objectives. We then turn to the geographical, demographic and cultural characteristics that make Darwin a challenging and distinct context for translation of global theories of creative city rejuvenation. As well as arguing a case for more nuanced, locationally specific, analysis of the capacity of places to embrace travelling policy discourses, we suggest ways in which creative city research can be refreshed through engaging with literatures on (post)colonial urban politics and intersections with policy initiatives other than those targeted at 'creative industries' per se . We systematically outline the particular challenges that tropical cities in remote locations provide to accepted wisdom about creativity-led urban planning. 相似文献
512.
Chris Doyle 《Pure and Applied Geophysics》2014,171(1-2):87-94
The Vancouver 2010 Winter Olympics were held from 12 to 28 February 2010, and the Paralympic events followed 2 weeks later. During the Games, the weather posed a grave threat to the viability of one venue and created significant complications for the event schedule at others. Forecasts of weather with lead times ranging from minutes to days helped organizers minimize disruptions to sporting events and helped ensure all medal events were successfully completed. Of comparable importance, however, were the scenarios and forecasts of probable weather for the winter in advance of the Games. Forecasts of mild conditions at the time of the Games helped the Games' organizers mitigate what would have been very serious potential consequences for at least one venue. Snowmaking was one strategy employed well in advance of the Games to prepare for the expected conditions. This short study will focus on how operational decisions were made by the Games' organizers on the basis of both climatological and snowmaking forecasts during the pre-Games winter. An attempt will be made to quantify, economically, the value of some of the snowmaking forecasts made for the Games' operators. The results obtained indicate that although the economic value of the snowmaking forecast was difficult to determine, the Games' organizers valued the forecast information greatly. This suggests that further development of probabilistic forecasts for applications like pre-Games snowmaking would be worthwhile. 相似文献
513.
The eruptive history and chemical stratigraphy of a post-caldera,steady-state volcano: Yasur,Vanuatu
Chris W. Firth Heather K. Handley Shane J. Cronin Simon P. Turner 《Bulletin of Volcanology》2014,76(7):1-23
The persistent activity of Yasur volcano, a post-caldera scoria cone in the southern Vanuatu Arc, along with the uniformity exhibited by its eruptive products, indicates that it is a “steady-state” volcano. This implies that rates of magma replenishment and tapping are in equilibrium. Examination of recently exposed tephra sequences suggests that Strombolian-style activity at Yasur has persisted in its current form for the last 630–850 years. Eruption of tephra with uniform grain size and texture throughout this period indicates invariant eruption magnitude and style. Based on tephra accumulation rates, a uniform, time-averaged eruption flux of ~410–480 m3 days?1 is estimated. Major and trace element analyses of glass shards and mineral grains from these tephra deposits show limited variation in magma composition throughout that time, consistent with a chemically buffered magma reservoir and models for steady-state volcanism. Similarly, mineral crystallisation temperature estimates are within error, suggesting the magma reservoir has retained a constant temperature through this time, while pressure estimates suggest shallow crystallisation. Eruptions appear to be driven by gas release, with small fluctuations in magma chemistry and eruptive behaviour governed by perturbations in volatile flux. This period of steady-state activity was preceded by ~600 years of higher-magnitude, lower-frequency eruptions during which less evolved compositions were erupted. Variation between these two styles of eruptive behaviour may be explained by a shift from a periodically closed to fully opened conduit, allowing more regular magma release and changes to degassing regimes. New radiocarbon ages suggest a period of irregular eruptive behaviour extending >1,400 year B.P. Overall, a transition from an irregular to a very steady magmatic system has occurred over the past ~2 kyr. Previously determined tectonic indicators for caldera resurgence in the area suggest revived magma replenishment after a hiatus following the caldera-forming Siwi eruption. This replenishment, while now supplying today’s constant activity, has not yet manifested itself in variations in composition or style/magnitude of eruptions. 相似文献
514.
Chris J. Hulatt Hermanni Kaartokallio Eero Asmala Riitta Autio Colin A. Stedmon Eloni Sonninen Markku Oinonen David N. Thomas 《Aquatic Sciences - Research Across Boundaries》2014,76(3):393-404
The radiocarbon age and biodegradability of dissolved organic matter (DOM) from a northern peat-dominated river system was studied and the effects of land-use were compared. Samples were obtained from streams and ditches comprising sub-catchments of the Kiiminki River, Northern Finland. Sample sites included areas of natural mire, areas subjected to moderate disturbance (ditching to enhance forestry), and areas subjected to serious land use change (agriculture and peat excavation). The study employed a 55 day bioassay that measured the biodegradation potential of surface-water DOM. We identified release of modern (mean 6–13 year old) DOM from natural sites, and material aged up to 1,553 years from disturbed sites. The proportion of biodegradable DOC ranged from 4.1 to 17.9 %, and bacterial DOC removal was modelled using twin-pool and reactivity-continuum (beta distribution) approaches. Bacterial growth efficiency ranged from 0.11 to 0.26 between areas of different land use, and these relatively low values reflect the humic-rich DOM released from boreal peatland. Despite the range of land-use types studied, including intensive peatland excavation areas, there was no detectable relationship between the biological lability of DOM and its radiocarbon age. 相似文献
515.
Ken Moran Sergio Pezoa Chris Fairall Chris Williams Tom Ayers Alan Brewer Simon P. de Szoeke Virendra Ghate 《Boundary-Layer Meteorology》2012,143(1):3-24
Cloud radars at X, Ka and W-bands have been used in the past for ocean studies of clouds, but the lack of suitable stabilization
has limited their usefulness in obtaining accurate measurements of the velocity structure of cloud particles and the heights
of cloud features. A 94 GHz (W-band) radar suitable for use on shipboard studies of clouds has been developed that is small
and lightweight and can maintain the radar’s beam pointing in the vertical to reduce the affects of the pitch and roll of
the ship. A vertical velocity sensor on the platform allows the effects of the ship’s heave to be removed from the measured
cloud particle motions. Results from the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-Rex) field program
on the NOAA vessel Ronald H. Brown demonstrate the improvements to the cloud measurements after the ship’s motion effects are removed. The compact design of
the radar also makes it suitable for use in aircraft studies. The radar is being repackaged to fit in an aft bay of a NOAA
P3 aircraft to observe sea-spray profiles during ocean storms. 相似文献
516.
Recent summer precipitation trends in the Greater Horn of Africa and the emerging role of Indian Ocean sea surface temperature 总被引:1,自引:0,他引:1
A. Park Williams Chris Funk Joel Michaelsen Sara A. Rauscher Iain Robertson Tommy H. G. Wils Marcin Koprowski Zewdu Eshetu Neil J. Loader 《Climate Dynamics》2012,39(9-10):2307-2328
We utilize a variety of climate datasets to examine impacts of two mechanisms on precipitation in the Greater Horn of Africa (GHA) during northern-hemisphere summer. First, surface-pressure gradients draw moist air toward the GHA from the tropical Atlantic Ocean and Congo Basin. Variability of the strength of these gradients strongly influences GHA precipitation totals and accounts for important phenomena such as the 1960s–1980s rainfall decline and devastating 1984 drought. Following the 1980s, precipitation variability became increasingly influenced by the southern tropical Indian Ocean (STIO) region. Within this region, increases in sea-surface temperature, evaporation, and precipitation are linked with increased exports of dry mid-tropospheric air from the STIO region toward the GHA. Convergence of dry air above the GHA reduces local convection and precipitation. It also produces a clockwise circulation response near the ground that reduces moisture transports from the Congo Basin. Because precipitation originating in the Congo Basin has a unique isotopic signature, records of moisture transports from the Congo Basin may be preserved in the isotopic composition of annual tree rings in the Ethiopian Highlands. A negative trend in tree-ring oxygen-18 during the past half century suggests a decline in the proportion of precipitation originating from the Congo Basin. This trend may not be part of a natural cycle that will soon rebound because climate models characterize Indian Ocean warming as a principal signature of greenhouse-gas induced climate change. We therefore expect surface warming in the STIO region to continue to negatively impact GHA precipitation during northern-hemisphere summer. 相似文献
517.
In a media saturated world of globalization, information flow and knowledge economies, an interesting paradox exists: geographic
literacy appears to be on the decline while geographic information is on the rise. In this introduction to a collection of
essays on geographies of the media, we explore this paradox and use Baudrillard’s (1994) work on Simulacra and Simulation to argue that increased mediated information does not produce more meaning, but rather leads to a catastrophe of meaning
and the medium. Drawing from McLuhan’s axiom, “the medium is the message,” we posit that with more mediated information there
is less meaningful information and as such we need to address geographic media literacy as a primary mode through which to
address geographic literacy.
相似文献
Jim CraineEmail: |
518.
根据云南南洞地下河系统2008年旱季的水化学分析结果,利用因子分析方法探讨地下水水质的影响因素及程度,结果表明:流域地下水成分变动范围较大,具有明显的空间变异性;地下水水质受人类活动、水岩作用过程和土壤等自然因素的共同影响,三个因素能够解释地下水水质形成的79%,其中人类活动是主要影响因素;地下水中的Cl-、NO3-、SO42-、Na+、K+主要受人类活动特别是农业和生活废水等因素的控制,Ca2+主要是水-岩作用的产物,但也受人类活动的影响,pH值、电导率受水岩作用过程和人类活动的影响,Mg2+、HCO3-受土壤CO2含量和水-岩作用过程的共同影响。 相似文献
519.
Sarah E. Coulter Chris S.M. Turney Peter Kershaw Susan Rule 《Quaternary Science Reviews》2009,28(19-20):1825-1830
Lynch's Crater provides the main reference section for late Quaternary environmental change in northeast Australia. We have identified a cryptotephra horizon within late Marine Isotope Stage-5 (MIS-5) lake sediments obtained from the site. The major element geochemistry of this tephra has been compared with data from southwest Pacific sources, and our results indicate that the cryptotephra is most likely to be of Papuan origin. This is the first discovery of an aerially derived tephra in Australia that originated from outside the mainland. The Lynch's Crater tephra is potentially an important marker horizon which could be used to connect disparate palaeoarchives at a time of significant climatic and environmental change. 相似文献
520.
Tom?RaimondoEmail authorView authors OrcID profile Justin?Payne Benjamin?Wade Pierre?Lanari Chris?Clark Martin?Hand 《Contributions to Mineralogy and Petrology》2017,172(4):17
A persistent problem in the study of garnet geochemistry is that the consideration of major elements alone excludes a wealth of information preserved by trace elements, particularly the rare-earth elements (REEs). This is despite the fact that trace elements are generally less vulnerable to diffusive resetting, and are sensitive to a broader spectrum of geochemical interactions involving the entire mineral assemblage, including the growth and/or dissolution of accessory minerals. We outline a technique for the routine acquisition of high-resolution 2D trace element maps by LA-ICP-MS, and introduce an extension of the software package XMapTools for rapid processing of LA-ICP-MS data to visualise and interpret compositional zoning patterns. These methods form the basis for investigating the mechanisms controlling geochemical mobility in garnet, which are argued to be largely dependent on the interplay between element fractionation, mineral reactions and partitioning, and the length scales of intergranular transport. Samples from the Peaked Hill shear zone, Reynolds Range, central Australia, exhibit contrasting trace element distributions that can be linked to a detailed sequence of growth and dissolution events. Trace element mapping is thus employed to place garnet evolution in a specific paragenetic context and derive absolute age information by integration with existing U–Pb monazite and Sm–Nd garnet geochronology. Ultimately, the remarkable preservation of original growth zoning and its subtle modification by subsequent re-equilibration is used to ‘see through’ multiple superimposed events, thereby revealing a previously obscure petrological and temporal record of metamorphism, metasomatism, and deformation. 相似文献