Chemical Composition of Suspended Particles in an Estuarine Turbidity Maximum Zone

1983 ◽  
Vol 40 (S1) ◽  
pp. s201-s206 ◽  
Author(s):  
D. H. Loring ◽  
R. T. T. Rantala ◽  
A. W. Morris ◽  
A. J. Bale ◽  
R. J. M. Howland
Keyword(s):  
River Flow ◽  
Suspended Particle ◽  
Suspended Particles ◽  
Turbidity Maximum ◽  
Estuarine Turbidity Maximum ◽  
Tamar Estuary ◽  
Correlation Matrices ◽  
Spatial Differences ◽  
Chemical Conditions ◽  
High River Flow

The detrital and nondetrital elemental compositions of suspended particles in the Tamar Estuary, U.K., have been examined when the estuarine turbidity maximum was well developed and also when high river flow restricted the development of a turbidity maximum. Correlation matrices and 'r'-mode factor analyses were used to identify significant relationships within and between the variances in the fractionated particulate compositions and in the ambient physico-chemical conditions. Marked temporal and spatial differences in the elemental composition of suspended particles were found. At high river flow, suspended particulate compositions throughout the estuary were dominated by dilution and dispersion of an overwhelming flux of riverborne material. Under normal conditions of low riverine particle flux, internal cycling of particles, especially within the turbidity maximum region, controlled the spatial distributions of suspended particle compositions and subsidiary inputs were of greater significance.Key words: estuaries, suspended sediment, particle transport, trace elements

scholarly journals Dynamics of the Estuarine Turbidity Maximum Zone from Landsat-8 Data: The Case of the Maroni River Estuary, French Guiana

2020 ◽  
Vol 12 (13) ◽  
pp. 2173 ◽  
Author(s):  
Noelia Abascal-Zorrilla ◽  
Vincent Vantrepotte ◽  
Nicolas Huybrechts ◽  
Dat Dinh Ngoc ◽  
Edward J. Anthony ◽  
...  
Keyword(s):  
River Flow ◽  
Temporal Dynamics ◽  
Spring Tide ◽  
River Estuary ◽  
Turbidity Maximum ◽  
Sediment Supply ◽  
Estuarine Turbidity Maximum ◽  
Landsat 8 ◽  
Residual Circulation ◽  
Spatio Temporal

The estuarine turbidity maximum (ETM) zone occurs in river estuaries due to the effects of tidal dynamics, density-driven residual circulation and deposition/erosion of fine sediments. Even though tropical river estuaries contribute proportionally more to the sediment supply of coastal areas, the ETM in them has been hardly studied. In this study, surface suspended particulate matter (SPM) determined from OLI (Operational Land Imager)-Landsat 8images was used to gain a better understanding of the spatio-temporal dynamics of the ETM of the tropical Maroni estuary (located on the Guianas coast, South America). A method to estimate the remotely-sensed ETM location and its spatiotemporal evolution between 2013 and 2019 was developed. Each ETM was defined from an envelope of normalized SPM values > 0.6 calculated from images of the estuary. The results show the influence of the well-marked seasonal river discharge and of tides, especially during the dry season. The ETM is located in the middle estuary during low river-flow conditions, whereas it shifts towards the mouth during high river flow. Neap–spring tidal cycles result in a push of the ETM closer to the mouth under spring-tide conditions or even outside the mouth during the rainy season. An increase in SPM, especially since 2017, coincident with an extension of the ETM, is shown to reflect the periodic influence of mud banks originating from the mouth of the Amazon and migrating along the coast towards the Orinoco (Venezuela). These results demonstrate the advantages of ocean color data in an exploratory study of the spatio-temporal dynamics of the ETM of a tropical estuary, such as that of the Maroni.

scholarly journals TEMPERATURE-SENSITIVE MUTATIONS OF THE NOTCH LOCUS IN DROSOPHILA MELANOGASTER

Genetics ◽  
1975 ◽  
Vol 81 (1) ◽  
pp. 143-162 ◽  
Author(s):  
David L Shellenbarger ◽  
J Dawson Mohler
Keyword(s):  
Temperature Shift ◽  
Temperature Sensitive ◽  
Spatial Differences ◽  
Region Temperature ◽  
Complex Locus ◽  
Notch Locus ◽  
Temporal And Spatial ◽  
Chemical Conditions ◽  
Interallelic Complementation ◽  
The Right

ABSTRACT Temperature-conditional mutations of the Notch locus were characterized in an attempt to understand the organization of a "complex locus" and the control of its function in development. Among 21 newly induced Notch alleles, about one-half are temperature-conditional for some effects, and three are temperature-sensitive for viability. One temperature-sensitive lethal, l(1)Nts1, is functionally non-complementing for all known effects of Notch locus mutations and maps at a single site within the locus. Among the existing alleles involved in complex patterns of interallelic complementation, Ax59d5 is found to be temperature-sensitive, while fag, spl, and l(1)N are temperature-independent. Whereas temperature-sensitive alleles map predominantly to the right-most fifth of the locus, fag, spl, and l(1)N are known to map to the left of this region. Temperature-shift experiments demonstrate that fag, spl, and l(1)N cause defects at specific, non-overlapping times in development.—We conclude (1) that the Notch locus is a single cistron (responsible for a single functional molecule, presumably a polypeptide); (2) that the right-most fifth of the locus is, at least in part, the region involved in coding for the Notch product; (3) that the complexity of interallelic complementation is a developmental effect of mutations that cause defects at selected times and spaces, and that complementation occurs because the mutant defects are temporally and spatially non-overlapping; and (4) that mutants express selected defects due to critical temporal and spatial differences in the chemical conditions controlling the synthesis or function of the Notch product. The complexity of the locus appears to reside in controlling the expression (synthesis or function) of the Notch product in development.

scholarly journals Enhanced methane oxidation in an estuarine turbidity maximum

2007 ◽  
Vol 52 (1) ◽  
pp. 470-475 ◽  
Author(s):  
Gwenaël Abril ◽  
Marc-Vincent Commarieu ◽  
Frédéric Guérin
Keyword(s):  
Methane Oxidation ◽  
Turbidity Maximum ◽  
Estuarine Turbidity Maximum

Variability Of Suspended Particle Concentrations, Sizes, And Settling Velocities In The Chesapeake Bay Turbidity Maximum

2004 ◽  
pp. 211-236 ◽  
Author(s):  
David Fugate ◽  
Heidi Romine ◽  
Patrick Dickhudt ◽  
Marissa Yates ◽  
Laura Rubiano-Gomez ◽  
...  
Keyword(s):  
Chesapeake Bay ◽  
Suspended Particle ◽  
Turbidity Maximum

scholarly journals Anomalies and trends of high river flow under temperate climatic conditions in north-eastern Romania

2020 ◽  
Author(s):  
Ionuț Minea ◽  
Oana Elena Chelariu
Keyword(s):  
Water Resource Management ◽  
River Flow ◽  
Climatic Conditions ◽  
High Flow ◽  
Data Sets ◽  
Pi Index ◽  
Starting Point ◽  
North Eastern ◽  
Management Plans ◽  
High River Flow

Abstract Regional water resource management plans include various scenarios related to the anomalies and trends of hydro-climatic parameters. Two methods are used for the identification of the anomalies and trends associated with high flow (annual and seasonal) of the rivers in Eastern Romania, namely the quantile perturbation method (QPM) and the partial trend method (PMT). These methods were selected due to the fact that they are suitable for data sets which do not rely on restrictive statistical assumption as common parametric and nonparametric trend tests do. For six of the nine stations analyzed, the decreasing trend in high extremes for annual high flow based on the PTM is the same as the annual trend obtained with the QPM. Using the PI index (associated with PTM) for the estimation of trend intensity, values between −2.280 and −9.015 m3/s were calculated for the decreasing trend of the annual high flow and between +1,633 m3/s (in autumn) and −9.940 m3/s (in summer) for the seasonal high flow. The results obtained on the anomalies and trends of high river flow may represent a starting point in the analysis of the evolution of water resources and their effective management.

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