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671.
Richard C. Franklin Jemma C. King Peter J. Aitken Peter A. Leggat 《Natural Hazards》2014,73(3):1977-1998
This article explored the perceptions of residents of a regional city in North Queensland of how to remain safe during flood events. It also explored reasons for and how to prevent risk-taking behaviour in floodwater using the protection motivation theory (PMT). PMT is a psychological theory which has recently been applied to assess behaviour during floods and was used as a framework to analyse the themes of responses to the online survey. The online survey was conducted prior to the wet season of 2011/2012 with 130 Townsville residents participating. The results indicate that about half of respondents (55 %) had some experience with floods of which driving through floodwater (38 %) was the most common type of flood experience listed and was more common amongst male respondents. Respondents’ advice to keep friends and family safe during floods was consistent with “coping appraisal”, which would improve their ability to cope with the flood. Prior experiences with floodwater influenced the reasons given for why people drive through floodwater and were taken to be indicative of an actor/observer bias. Respondents who had experience driving through floodwater (the actors) indicate how the context of the situation can influence decision-making, whereas those respondents who had no personal experience of driving through floodwater (the observers) were more likely to cite low perceived vulnerability of harm as a motivator. Prevention strategies focused on structural mechanisms to block access, information provision and punishment of offenders. It is suggested that in communities which regularly experience flooding, timely and context-specific reminders of the dangers inherent in floodwater along with the type, effectiveness and cost of protective action could minimise the public’s contact with floodwater and prove useful regardless of past experiences. 相似文献
672.
John F. Pernet-Fisher Geoffrey H. Howarth Yang Liu Peter H. Barry Laura Carmody John W. Valley Robert J. Bodnar Zdislav V. Spetsius Lawrence A. Taylor 《Contributions to Mineralogy and Petrology》2014,167(3):1-17
The Komsomolskaya kimberlite is one of numerous (>1,000) kimberlite pipes that host eclogite xenoliths on the Siberian craton. Eclogite xenoliths from the adjacent Udachnaya kimberlite pipe have previously been geochemically well characterized; however, data from surrounding diamond-bearing kimberlite pipes from the center of the craton are relatively sparse. Here, we report major- and trace-element data, as well as oxygen isotope systematics, for mineral separates of diamondiferous eclogite xenoliths from the Komsomolskaya kimberlite, suggesting two distinct subgroups of a metamorphosed, subducted oceanic crustal protolith. Using almandine contents, this suite can be divided into two subgroups: group B1, with a high almandine component (>20 mol%) and group B2, with a low almandine component (<20 mol%). Reconstructed REE profiles for B1 eclogites overlap with typical oceanic basalts and lack distinct Eu anomalies. In addition, elevated oxygen isotope values, which are interpreted to reflect isotopic exchange with seawater at low temperatures (<350 °C), are consistent with an upper-oceanic crustal protolith. Reconstructed REE profiles for B2 eclogites are consistent with oceanic gabbros and display distinct Eu anomalies, suggesting a plagioclase-rich cumulate protolith. In contrast to B1, B2 eclogites do not display elevated oxygen isotope values, suggesting an origin deep within the crustal pile, where little-to-no interaction with hydrothermal fluids has occurred. Major-element systematics were reconstructed based on mineral modes; group B1 eclogites have higher MgO wt% and lower SiO2 wt%, with respect to typical oceanic basalts, reflecting a partial melting event during slab subduction. Calculated residues from batch partial melt modeling of a range of Precambrian basalts overlap with group B1 trace-element chemistry. When taken together with the respective partial melt trajectories, these melting events are clearly linked to the formation of Tonalite–Trondhjemite–Granodiorite (TTG) complexes. As a result, we propose that many, if not all, diamondiferous eclogite xenoliths from Komsomolskaya represent mantle ‘restites’ that preserve chemical signatures of Precambrian oceanic crust. 相似文献
673.
Peter HUDSON 《《地质学报》英文版》2014,88(Z1):73-73
正Lakes Acraman,Gairdner,Harris and Everard are a cluster of large episodic salt lakes on Eyre Peninsula,South Australia.These lakes have a characteristic terrestrial invertebrate fauna including various spiders, 相似文献
674.
Self‐localization is the process of identifying one's current position on a map, and it is a crucial part of any wayfinding process. During self‐localization the wayfinder matches visually perceptible features of the environment, such as landmarks, with map symbols to constrain potential locations on the map. The success of this visual matching process constitutes an important factor for the success of self‐localization. In this research we aim at observing the visual matching process between environment and map during self‐localization with real‐world mobile eye tracking. We report on one orientation and one self‐localization experiment, both in an outdoor urban environment. The gaze data collected during the experiments show that successful participants put significantly more visual attention to those symbols on the map that were helpful in the given situation than unsuccessful participants. A sequence analysis revealed that they also had significantly more switches of visual attention between map symbols and their corresponding landmarks in the environment, which suggests they were following a more effective self‐localization strategy. 相似文献
675.
In geographic information science, a plethora of different approaches and methods is used to assess the similarity of movement. Some of these approaches term two moving objects similar if they share akin paths. Others require objects to move at similar speed and yet others consider movement similar if it occurs at the same time. We believe that a structured and comprehensive classification of movement comparison measures is missing. We argue that such a classification not only depicts the status quo of qualitative and quantitative movement analysis, but also allows for identifying those aspects of movement for which similarity measures are scarce or entirely missing.In this review paper we, first, decompose movement into its spatial, temporal, and spatiotemporal movement parameters. A movement parameter is a physical quantity of movement, such as speed, spatial path, or temporal duration. For each of these parameters we then review qualitative and quantitative methods of how to compare movement. Thus, we provide a systematic and comprehensive classification of different movement similarity measures used in geographic information science. This classification is a valuable first step toward a GIS toolbox comprising all relevant movement comparison methods. 相似文献
676.
Peter A. Gilman 《Solar physics》1969,9(1):3-18
To make the analysis more tractable, we simplify the equations of Part I to apply to two superposed layers of fluid, with horizontal variations in the motion and magnetic field represented by a small number of Fourier harmonics. The resulting set of eighteen ordinary nonlinear differential equations in time for the Fourier amplitudes is integrated numerically. We analyze in detail the dynamo action from a typical Rossby wave motion and compare it with the solar cycle.The field reversal process is similar in some respects to that put forth by Babcock. Toroidal fields are dragged up by vertical motions in the Rossby waves to form large-scale vertical fields, whose polarities alternate with longitude roughly like bipolar magnetic regions. Vertical fields of preferentially one polarity are carried toward the pole by the meridional motion in the wave to form an axisymmetric poloidal field. This poloidal field is then stretched out by the differential rotation into a new toroidal field of the opposite sign from the original. The poloidal field changes sign when the toroidal and bipolar region like fields are maximum, and vice versa.For the case studied, the reversal period is too short ( 2 years) and the poloidal fields too large ( 40 G) for the sun. Improvements for the model are discussed.Part I has been published in Solar Phys.
8, 316. 相似文献
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680.
Peter Wilson Michael J. Bentley Christoph Schnabel Richard Clark Sheng Xu 《第四纪科学杂志》2008,23(5):461-473
Cosmogenic isotope (10Be and 26Al) surface exposure dating has been applied to valley‐axis and hillslope stone runs (relict periglacial block streams) and their source outcrops in the Falkland Islands, South Atlantic. The data indicate that stone runs are considerably older landforms than previously envisaged and afford no evidence that they are a product of the Last Glacial Maximum; the samples range in apparent 10Be age from 42k to 731k yr BP, but some of these are minima. The results indicate that valley‐axis stone runs may be up to 700–800k yr old, have simple exposure histories and are composite landforms that developed over several cold stages. Analyses of some hillslope and outcrop samples also demonstrate simple exposure histories with 10Be ages from 42k to 658k yr BP. In contrast, isotopic ratios from other hillslope and outcrop samples reveal they have had a complex exposure history involving periods of burial or shielding; the samples range in 10Be age from 59k to 569k yr BP and these are regarded as minimum age estimates. Larger stone runs may be older than smaller runs and there is a possibility that stone runs older than 800k yr exist in other parts of the Falklands. The assertion that glaciation in the Falklands was restricted to the highest uplands is supported by the data, and the potential for age determination of other boulder‐strewn and bedrock landforms, using cosmogenic isotope analysis, in order to extend the geochronology of Quaternary events and processes is noted. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献