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A long-term mark-recapture study was used to assess the movement patterns of surf-zone fishes in the St Lucia Marine Reserve, a marine protected area within the iSimangaliso Wetland Park, a World Heritage Site on the east coast of South Africa. Between 2001 and 2013, 6 613 fish from 71 species, caught by hook and line, were tagged at four sites within and adjacent to a no-take marine sanctuary area. A total of 1 004 (15.2%) recaptures were made from 17 species. The majority (82.4%) of these species displayed station-keeping behaviour, whereas only three were classified as wider-ranging species, and no species with discernible migratory behaviour was observed. Findings for five species with the highest recapture rates, namely Pomadasys furcatus, Epinephelus andersoni, E. marginatus, Dinoperca petersi and Lutjanus rivulatus, are presented in greater detail. Recapture rates ranged from 7% to 50% and time at liberty from 0 to 3 163 days. Individuals of all five species displayed station-keeping behaviour, with the 95th percentile of intra-study-site movements varying between 200 and 1 025 m (linear distance). However, four of the five species also displayed some ranging behaviour and made exploratory excursions ranging from 3.5 to 125 km, in both northerly and southerly directions. The dominance of station-keeping behaviour suggests that the St Lucia Marine Reserve sanctuary zone provides an important refuge for these species, with some export to adjacent areas. 相似文献
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J. C. Gower 《Mathematical Geosciences》1970,2(1):39-45
Some of the problems of weighting characters and of eliminating correlational effects between characters are discussed. Many different weighting schemes can be proposed for similarity coefficients even when, as in Burnaby’s coefficient, it is decided to give high weight to matches between rare states. The rarity of a character state must be considered relative to the sampling scheme used to select the sampling units. Similarities between all pairs of units may be analyzed to suggest groups among the units. Groups having many correlated characters may be the most useful but are unlikely to be found by numerical methods which eliminate correlational effects. 相似文献
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D S Mackay S Samanta D E Ahl B E Ewers S T Gower & S N Burrows 《Transactions in GIS》2003,7(1):139-153
All land surface process models require parameters that are proxies for spatial processes that are impractical or impossible to measure. Recent developments in model parameter estimation theory suggest that information obtained from calibrating such models is inherently uncertain in nature. As a consequence, identification of optimum parameter values is often highly non–specific. A calibration framework using fuzzy logic is presented to deal with such uncertain information. An application of this technique to calibrate the sub–canopy controls on transpiration in a land surface process model demonstrates that objective estimates of parameter values and expected ranges of predictions can be obtained with suitable choices for objective functions. An iterative refinement in parameter estimates was possible with conditional sampling techniques. The automated approach was able to correctly identify parameter tradeoffs such that two strongly different sets of parameters could 相似文献
47.
The compositions of multiply saturated partial melts are valuablefor the thermodynamic information that they contain, but aredifficult to determine experimentally because they exist onlyover a narrow temperature range at a given pressure. Here wetry a new approach for determining the composition of the partialmelt in equilibrium with olivine, orthopyroxene, clinopyroxeneand spinel (Ol + Opx + Cpx + Sp + Melt) in the system CaOMgOAl2O3SiO2(CMAS) at 1·1 GPa: various amounts of K2O are added tothe system, and the resulting melt compositions and temperatureare extrapolated to zero K2O. The sandwich experimentalmethod was used to minimize problems caused by quench modification,and Opx and Cpx were previously synthesized at conditions nearthose of the melting experiments to ensure they had appropriatecompositions. Results were then checked by reversal crystallizationexperiments. The results are in good agreement with previouswork, and establish the anhydrous solidus in CMAS to be at 1320± 10°C at 1·1 GPa. The effect of K2O is todepress the solidus by 5·8°C/wt %, while the meltcomposition becomes increasingly enriched in SiO2, being quartz-normativeabove 4 wt % K2O. Compared with Na2O, K2O has a stronger effectin depressing the solidus and modifying melt compositions. Theisobaric invariant point in the system CMASK2O at whichOl + Opx + Cpx + Sp + Melt is joined by sanidine (San) is at1240 ± 10°C. During the course of the study severalother isobaric invariant points were identified and their crystaland melt compositions determined in unreversed experiments:Opx + Cpx + Sp + An + Melt in the system CMAS at 1315 ±10°C; in CMASK2O, Opx + Cpx + Sp + An + San + Meltat 1230 ± 10°C and Opx + Sp + An + San + Sapph +Melt at 1230 ± 10°C, where An is anorthite and Sapphis sapphirine. Coexisting San plus An in three experiments helpdefine the AnSan solvus at 12301250°C. KEY WORDS: feldspar solvus; igneous sapphirine; mantle solidus; partial melting; systems CMAS and CMASK2O 相似文献
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The sunglint areas of the ocean in NOAA satellite visible imagery appear as long swaths that extend from the northern extremes of the North Temperate Zone to the southern extreme of the South Temperate Zone. Examples are shown of complex features apparent in the sunglint area of visible imagery that closely match ocean-related thermal features in the companion infrared imagery. Various interpretations of these features are discussed. Data from the first phase of the Grand Banks Experiment (June 1978) are presented which demonstrate that such sunglint features are related to the strong ocean frontal processes present in this area. Although some of the features may be associated with fog or mist, side-looking airborne radar imagery collected during the experiment confirms the presence of surface roughness variations. The observations strongly suggest that these roughness variations are due to changes in the stability of the atmospheric boundary layer caused by the different surface water temperatures present in the area. The results demonstrate the usefulness of NOAA visible imagery as a tool to aid in the understanding of synoptic ocean processes, and suggest an important application for satellite and airborne synthetic aperture radars in mapping the roughness changes associated with ocean current systems. 相似文献
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S. P. SCHWENZER J. FRITZ D. STÖFFLER M. TRIELOFF M. AMINI A. GRESHAKE S. HERRMANN K. HERWIG K. P. JOCHUM R. K. MOHAPATRA B. STOLL U. OTT 《Meteoritics & planetary science》2008,43(11):1841-1859
Abstract— Noble gas data from Martian meteorites have provided key constraints about their origin and evolution, and their parent body. These meteorites have witnessed varying shock metamorphic overprinting (at least 5 to 14 GPa for the nakhlites and up to 45–55 GPa (e.g., the lherzolitic shergottite Allan Hills [ALH] A77005), solar heating, cosmic‐ray exposure, and weathering both on Mars and Earth. Influences on the helium budgets of Martian meteorites were evaluated by using a new data set and literature data. Concentrations of 3He, 4He, U, and Th are measured and shock pressures for same sample aliquots of 13 Martian meteorites were determined to asses a possible relationship between shock pressure and helium concentration. Partitioning of 4He into cosmogenic and radiogenic components was performed using the lowest 4He/3He ratio we measured on mineral separates (4He/3He = 4.1, pyroxene of ALHA77005). Our study revealed significant losses of radiogenic 4He. Systematics of cosmogenic 3He and neon led to the conclusion that solar radiation heating during transfer from Mars to Earth and terrestrial weathering can be ruled out as major causes of the observed losses of radiogenic helium in bulk meteorites. For bulk rock we observed a correlation of shock pressure and radiogenic 4He loss, ranging between ?20% for Chassigny and other moderately shocked Martian meteorites up to total loss for meteorites shocked above 40 GPa. A steep increase of loss occurs around 30 GPa, the pressure at which plagioclase transforms to maskelynite. This correlation suggests significant 4He loss induced by shock metamorphism. Noble gas loss in rocks is seen as diffusion due to (1) the temperature increase during shock loading (shock temperature) and (2) the remaining waste heat after adiabatic unloading (post shock temperature). Modeling of 4He diffusion in the main U, Th carrier phase apatite showed that post‐shock temperatures of ?300 °C are necessary to explain observed losses. This temperature corresponds to the post‐shock temperature calculated for bulk rocks shocked at about 40 GPa. From our investigation, data survey, and modeling, we conclude that the shock event during launch of the meteorites is the principal cause for 4He loss. 相似文献
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Desorption-diffusion model and lost gas quantity estimation of coalbed methane from coal core under drilling fluid medium 总被引:1,自引:0,他引:1
Geoff WANG 《中国科学:地球科学(英文版)》2010,(4)
The differences of coalbed methane(CBM) desorption-diffusion from coal drilling-core under various drilling fluid medium are not considered in the present calculating methods of lost CBM quantity,which leads possibly to the inaccuracy of CBM quantity in coal seam.Here we took the desorption of CBM from coal core under drilling fluid medium as a pressure-swing process,and based on the Langmuir equation and Fick-first law,established the desorption-diffusion model and numerical modeling method of lost gas(inc... 相似文献