Quantifying particle aggregation in sediments     

DAVID HABERLAH  GRANT H. MCTAINSH 《Sedimentology》2011,58(5):1208-1216

Sediments often occur as non‐normal size distributions composed of discrete, partially aggregated particle populations. These populations reflect provenance, dispersal pathways and their depositional environments. Recent experimental laboratory studies describing mud flocculation in turbulent marine systems prompted this investigation of the potential of aggregates to record size‐sensitive transport dynamics in a terrestrial fluvial system. Here, sediment‐size distributions in their natural condition of particle–aggregate mixtures are analysed by parametric statistics. A practical and freely available decompositional approach is outlined and field tested, which allows sediment to be viewed in both its conventional particulate form and as its naturally occurring mixture of transport‐stable aggregates and elementary particles. From a sequence of upward‐fining slack water couplets in the Flinders Ranges, South Australia, it is demonstrated that the characteristics, provenance and depositional history of fine‐grained sediments consisting of particle‐aggregate mixtures can best be understood fully by quantifying aggregation.  相似文献   

On the secondary meridional circulation associated with the quasi-biennial oscillation     

WOOKAP CHOI  HYUNAH LEE  WILLIAM B. GRANT  JAE H. PARK  JAMES R. HOLTON  KWANG-MOG LEE  BARBARA NAUJOKAT 《Tellus. Series B, Chemical and physical meteorology》2002,54(4):395-406

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RADAR MEASUREMENTS OF METEOROID DECELERATIONS     

W. J. BAGGALEY  J. GRANT 《Earth, Moon, and Planets》2004,95(1-4):647-654

Measurements of meteoroid velocities and decelerations have been obtained from post-t ₀ diffraction patterns present in echo signatures obtained from the multi-site AMOR radar operated at the University of Canterbury’s research facility. The system allows the sampling of a meteoroid’s velocity at separated points along the body’s trajectory to yield decelerations. The technique has potential value in providing data on the relation between trajectory behaviour, drag characteristics, the physical structure of meteoroids and stream membership or orbit type.  相似文献   

REVIEWS     

A. GRANT ANDERSON 《New Zealand geographer》1967,23(2):173-174

Book reviewed in this article:
NORTHLAND REGION. National Resources Survey, Part III. Wellington: Town and Country Planning Branch, Ministry of Works
ECONOMIC SURVEY OF NORTHLAND. Department of Industries and Commerce  相似文献   

Climatic influence upon early to mid‐Holocene fire regimes within temperate woodlands: a multi‐proxy reconstruction from the New Forest,southern England          下载免费PDF全文

M. J. GRANT  P. D. M. HUGHES  K. E. BARBER 《第四纪科学杂志》2014,29(2):175-188

A combined pollen, charcoal and climatic record is presented from Cranes Moor, southern England, covering the period c. 10 500–5850 cal a BP. It is shown that the occurrence of burning is closely related to natural processes, including prevailing climatic conditions and vegetation composition. These burning events are often linked to an increase in the summer moisture deficit, implying that the timing of burning events is linked to periods of warmer/drier climate during the Holocene Thermal Maximum (c. 11 000–5000 cal a BP). These events play an important role in the vegetation composition and succession around the site. The nature of the burning recorded at the site shows strong similarities with other records from northern Europe. This study throws caution on suggestions that fire in the Holocene record from areas such as the British Isles is linked only to human activity, and enhances the possibility that natural fire incidence played an important role in natural woodland structure dynamics.  相似文献   

''Cosmogenic ¹⁰Be ages on the Pomeranian Moraine, Poland'': Reply to comments     

VINCENT R. RINTERKNECHT  LESZEK MARKS  JAN A. PIOTROWSKI  GRANT M. RAISBECK  FRANCOISE YIOU  EDWARD J. BROOK  PETER U. CLARK 《Boreas: An International Journal of Quaternary Research》2006,35(3):605-606

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A cold air outbreak over the Norwegian Sea observed with the TIROS-N Operational Vertical Sounder (TOVS) and the Special Sensor Microwave/Imager (SSM/I)     

CHANTAL CLAUD†  KRISTINA B. KATSAROS  GRANT W. PETTY  ALAIN CHEDIN†  NOELLE A. SCOTT† 《地球，A辑:动力气象学与海洋学》1992,44(2):100-118

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Æolian dust deposition rates, particle-sizes and contributions to soils along a transect in semi-arid New South Wales, Australia     

STEPHEN R. CATTLE  GRANT H. MCTAINSH†  SHERWIN ELIAS 《Sedimentology》2009,56(3):765-783

The entrainment, transport and deposition of æolian dust are important processes affecting soil development at the margins of deserts. To assess accurately the impact of deposited æolian dust on soil development, it is important not only to measure total dust deposition rates, but to distinguish additions of remotely and regionally sourced dust from locally derived material as well (which should not be viewed as new soil material as it is derived from æolian re‐mobilization of an existing soil). Because of the well‐established relationship between dust particle‐size and distance travelled from source, the particle‐size distribution of deposited dusts can be used to identify the distance to probable source regions, in addition to identifying matching topsoil particle populations. Three dust traps were located along a transect of semi‐arid south‐eastern Australia, to measure æolian dust deposition rates between late 2000 and late 2001. The particle‐size distributions of selected dust deposits were measured and, with the aid of meteorological data, probable dust source regions determined. Particle‐size distributions of the topsoils at each dust trap location were also measured to determine if any dust and soil particle populations matched. Although the sampling period was relatively short, and there was relatively little dust storm activity in this part of Australia during this time, a clear pattern of diminishing total dust deposition was measured downwind along the south‐east dust path. Dust deposition rates were also moderate to low by global standards. Source regions of deposited dust were interpreted as being: (i) a combination of south‐western and local sources; (ii) a combination of north‐western and local sources; and (iii) a mixed source where dust was rained‐out. The relative importance of these sources was correlated strongly with seasonal weather conditions, although the proportion of local dust in each deposit was greater at the arid (western) end of the transect. The effects of deposited dust on soil profile development are greatest at the western and central transect locations. At the western location, a fine‐grained particle population distinctive of the south‐western and north‐western regional dusts and a coarse silt‐sized particle population characteristic of local dusts, are also present in the topsoil, altering the texture of this Arenosol derived from dune sand. At the central location, where a Calcisol has formed in lacustrine lunette sediment, local dust of the same size as the dominant silt population of the topsoil continues to be deposited, while minor topsoil populations of very fine‐grained silt match regional and long‐distance dusts deposited at the site. Deposited dust appears to have been a less important soil development factor at the more humid eastern site because of the much smaller rates of dust deposition there. Nevertheless, a minor population of very fine silt particles in the Vertisol topsoil matches long‐distance dusts deposited at the site, suggesting a small input of dust to this alluvial soil. The particle‐size methodology used here has applications in other studies of dust contributions to peri‐desert soils. In particular, particle‐size distribution ‘smoothness’ may provide an indication of whether soils have simple or complex origins.  相似文献   

CANTERBURY AT THE CROSSROADS. Edited by R. D. Bedford and A. P. Sturman.     

A. GRANT ANDERSON 《New Zealand geographer》1984,40(2):119-119

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Aspects of Population Change in Palmerston North     

A. GRANT ANDERSON 《New Zealand geographer》1964,20(2):165-178

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