Laser diffraction size analysis

Agrawal, Y. C.; McCave, I Nick; Riley, J. B.

doi:10.1017/cbo9780511626142.012

Cited by 114 publications

(65 citation statements)

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“…Duplicate size spectra were obtained from all samples and care was taken to ensure the obscuration was within instrument tolerance (8 to 12 %). As laser particle size inversion software typically assumes a spherical particle shape (Agrawal et al, 2007), whilst natural sand grains are irregularly shaped, a number of samples were also sieved to provide an independent estimate of particle size spectra for comparison with those obtained using the Coulter.…”

Section: Mineralogical Composition and Particle Size Distributionmentioning

confidence: 99%

Field deployment and evaluation of a prototype autonomous two dimensional acoustic backscatter instrument: The Bedform And Suspended Sediment Imager (BASSI)

Moate

Thorne

Cooke

2016

Continental Shelf Research

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The processes of sediment entrainment, transport and deposition over bedforms are highly dynamic and temporally and spatially variable. However, most measurements of these processes tend to be collected in a vertical line at one spatial location above the bed; one dimensional in the vertical, 1D-V. Such measurements capture the temporal signature, and, to a lesser degree, the spatial variability when bedforms migrate, and they have contributed greatly to our understanding of sediment transport processes. It is generally acknowledged, however, that such 1D-V systems provide a limited description of the spatially three dimensional processes occurring at the turbulent and intra-wave time scales. It would undoubtedly facilitate the interpretation of fundamental sediment processes above bedforms if other spatial dimensions could be simultaneously interrogated. To this end a multifrequency acoustic array has been developed to measure suspended sediments and bedforms over a horizontal transect of the bed in the vertical, providing two dimensional observations in the vertical and horizontal, 2D-HV. This new acoustic instrument, the BASSI; Bedform And Suspended Sediment Imager, has been deployed in the River Dee tidal estuary in the UK. The design of the BASSI and results from the deployment are presented and its performance assessed against more conventional instrumentation. Measurements and images of 2D-HV suspended sediments and bedforms are provided to illustrate the capability and future use of the BASSI for the investigation of sediment transport processes.3

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Section: Mineralogical Composition and Particle Size Distributionmentioning

confidence: 99%

Field deployment and evaluation of a prototype autonomous two dimensional acoustic backscatter instrument: The Bedform And Suspended Sediment Imager (BASSI)

Moate

Thorne

Cooke

2016

Continental Shelf Research

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“…Sedigraph, settling tube, Coulter Counter and devices based on laser diffraction). Granulometric measurements of a sediment sample obtained with different techniques will inherently yield different results (see, for example, Sternberg and Creager 1961;Creager and Sternberg 1963;Sengupta and Veenstra 1968;Sanford and Swift 1971;Shideler 1976;Behrens 1978;Welch et al 1979;Komar and Cui 1984;Stein 1985;Coates and Hulse 1985;Levant et al 1985;McCave et al 1986;Singer et al 1988;Agrawal et al 1991;Weber et al 1991;Kench and McLean 1997;Buurman et al 1997Buurman et al , 2001Cramp et al 1997;Bianchi et al 1999;Olaisen et al 2001;Dur et al 2004;Scott-Jackson and Walkington 2005). Sieving and laser diffraction are currently the two main methods used for granulometric measurements.…”

Section: Granulometric Parametersmentioning

confidence: 99%

Reply to J.J. Muñoz-Perez et al. Comments on “Confirmation of beach accretion by grain-size trend analysis: Camposoto beach, Cádiz, SW Spain” by E. Poizot et al. (2013) Geo-Marine Letters 33(4)

Poizot

Anfuso²,

Méar³

et al. 2013

Geo-Mar Lett

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In a novel finding for a beach environment, Poizot et al. (2013) identified an FB+ trend (sediments becoming finer, better sorted and more positively skewed upshore) on a well-developed swash bar on the upper foreshore of the Camposoto beach of Cádiz in SW Spain. In their Discussion of that paper, Muñoz-Perez et al. (2014) provide some supporting arguments and also report grain-size, beach profile and other data from nearby beaches which differ from those of Poizot and colleagues for Camposoto beach, pointing out that a trend observed on one beach may not apply to a neighbouring beach. However, even though the absolute values differ, the overall trends actually do show the same general behaviour. In our Reply to their comments, we also address some difficulties in comparing granulometric datasets generated by different analytical techniques.

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“…Subsamples were analyzed for particle size variations using a Coulter LS-100 particle size analyzer. This instrument uses the principle of Fraunhofer diffraction of laser light in which light falling on suspended sediment particles is deflected (diffracted) by an amount that depends on the size of the particle (Agrawal et al, 1991). Subsamples were allowed to soak overnight in water, facilitating deflocculation.…”

Section: Particle Size Characteristicsmentioning

confidence: 99%

Late Quaternary Paleoenvironmental Change on the Northeast Australian Margin as Evidenced in Oxygen Isotope Stratigraphy, Mineral Magnetism, and Sedimentology

Alexander¹,

Kroon²,

Thompson³

1993

Proceedings of the Ocean Drilling Program

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To investigate late Quaternary paleoclimatic and paleoceanographic change in the sedimentary record, preserved on the Australian Continental Margin during the late Quaternary, core material was collected from Ocean Drilling Program, Leg 133, Site 819. An expanded sequence of late Quaternary, rhythmically bedded, predominantly hemipelagic sediments were recovered from Hole 819A. The foraminiferal δ 18 θ record preserved at Hole 819A suggests that the late Quaternary section is incomplete. Both benthic and planktonic δ 18 θ stratigraphies can be traced tentatively downcore to stage 9 at about 32.5 mbsf, where a major hiatus occurs. At this level, a slump detachment surface has been identified (Shipboard Scientific Party, 1991). This slump has removed marine oxygen isotope stages 10 to 13. Below 32.5 mbsf, continuous correlation can be achieved in the planktonic δ 18 θ curve, with existing deep-sea foraminiferal oxygen isotope stratigraphies from stage 14 through stage 28.The major hiatus at 32.5 mbsf marks the position of a significant change in the character of the sedimentation at Site 819. Sediments below 32.5 mbsf, relative to those above 32.5 mbsf, are characterized by less variation in mean particle size; lower percentages of carbonate content in the coarse fraction (>63 µm); a stronger relationship between the percentage of fine fraction and magnetic mineral concentration, and lower foraminiferal abundances. Above the hiatus, large fluctuations in mean particle size occurred, which have been interpreted to be the result of high foraminiferal abundances. Early highstands show high terrigenous influx in the fine fraction above the hiatus. This is the opposite of the general idea of high terrigenous influx during lowstands of sea level on siliciclastic dominated continental margins. We are far from understanding the origin of this material and further investigation will be required (see also Glenn et al., this volume).All our records, except the planktonic foraminiferal oxygen isotope record, indicate that the major hiatus marks the position of a significant change in the environment at Site 819. The planktonic foraminiferal δ 18 θ record suggests that environmental change occurred prior to the formation of the hiatus (i.e., near the Brunhes/Matuyama [B/M] boundary). The interval between the B/M boundary and the hiatus represents a transitional period between two different patterns of ocean circulation.Throughout most of the lower part of the sequence, Site 819 was at a shallow-water depth and local Oceanographic conditions were dominated by sluggish Subtropical Central Water (SCW) flow. However, near the B/M boundary, ocean circulation patterns intensified, reflecting a worldwide change in paleoenvironment. Enhanced ocean circulation patterns were possibly aided by tectonic subsidence. During this period Site 819 became progressively more under the influence of Antarctic Intermediate Water (AAIW), than SCW.In the upper part of the sequence at Hole 819 A, we see a continuation of the pattern of Oceanog...

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Laser diffraction size analysis

Cited by 114 publications

References 0 publications

Field deployment and evaluation of a prototype autonomous two dimensional acoustic backscatter instrument: The Bedform And Suspended Sediment Imager (BASSI)

Field deployment and evaluation of a prototype autonomous two dimensional acoustic backscatter instrument: The Bedform And Suspended Sediment Imager (BASSI)

Reply to J.J. Muñoz-Perez et al. Comments on “Confirmation of beach accretion by grain-size trend analysis: Camposoto beach, Cádiz, SW Spain” by E. Poizot et al. (2013) Geo-Marine Letters 33(4)

Late Quaternary Paleoenvironmental Change on the Northeast Australian Margin as Evidenced in Oxygen Isotope Stratigraphy, Mineral Magnetism, and Sedimentology

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