Estuaries definition

Carstensen, J., Henriksen, P, Heiskanen, A.-S., 2007. Summer algal blooms in shallow estuaries definition, mechanisms, and link to eutrophication. Limnology and Oceanography, 52, 370-384. 

There has been considerable debate about the definition of an estuary because of the divergent properties found within and among estuaries from different regions of the world. 

Prior to discussing the factors that control concentrations of the major dissolved components in rivers, estuaries, and oceans, it is important to discuss the operationally defined size spectrum for different phases (dissolved, colloidal, and particulate) of an element. The conventional definition for dissolved materials is the fraction of total material that... 

Elliot, M., and McLusky, D.S. (2002) The need for definitions in understanding estuaries. Estuar. Coastal Shelf Sci. 55, 815-827. 

Fairbridge, R.W. (1980) The estuary its definition and geologic cycle. In Chemistry and Biogeochemistry of Estuaries (Olausson, E., and Cato, I., eds.), pp. 1-36, Wiley-Interscience, New York. 

Perillo, G.M.E. (ed.) (1995) Definitions and geomorphic classifications of estuaries. In Geomorphology and Sedimentology of Estuaries. Developments in Sedimentology 53, pp. 17—47, Elsevier Science, New York. 

The accuracy of a measurement is a parameter used to determine just how close the determined value is to the true value for the test specimens. One problem with experimental science is that the true value is often not known. For example, the concentration of lead in the Humber Estuary is not a constant value and will vary depending upon the time of year and the sites from which the test specimens s are taken. Therefore, the true value can only be estimated, and of course will also contain measurement and sampling errors. The formal definition of accuracy is the difference between the experimentally determined mean of a set of test specimens, x, and the value that is accepted as the true or correct value for that measured analyte, /i0. The difference is known statistically as the error (e) of x, so we can write a simple equation for the error ... 

Rivers transport material in several phases dissolved, suspended particulate and bed load. Physical and chemical processes within an estuary infiuence the transportation and transformation of this material, thereby affecting the net supply of material to the oceans. Several definitions and geomorphologic classifications of estuaries have been reviewed by Pe-rillo (1995). From a chemical perspective, an estuary is most simply described as the mixing zone between river water and seawater characterised by sharp gradients in the ionic strength and chemical composition. Geographic distinctions can be made between drowned river valleys, fjords and bar-built estuaries. They can alternatively be classified in terms of the hydrodynamic regime as ... 

We report here measurements of the stable hydrogen Isotopic composition of methane and water, the stable carbon Isotopic composition of methane and carbon dioxide, and ancillary parameters from several freshwater environments and from a few locations within the Tampa Bay estuary. The stable Isotopic compositions determined In this study are reported as a parts-per-mll ( /oo) deviation (5) from a standard with a known stable isotopic ratio. The definition of the 6 value Is ... 

There are several definitions of fjords. The most common definition is a fjord is a deep, high-latitude estuary which has been (or is presently being) excavated or modified by land-based ice (Syvitski etal., 1987). This definition implies that fjords are only found in the northernmost and southernmost regions of the earth that once were ice covered. As a geological feature, fjords are the youngest of all estuaries since they were formed during the retreat of the glaciers and... 

Throughout the last century or so, many scientists have subscribed to the theory that the coal source material has not formed by the degradation of plant material in situ in a peat swamp environment but rather accumulated from the deposition of transported material in aqueous environments such as lakes, seas, and estuaries (Moore, 1940 Stutzer, 1940 Francis, 1961). Indeed, the concept of transportation of the source material also led to the belief that not one but several processes were responsible for the different types of coal. Thus, there was much thought and discussion which actually led to serious questions about the autochthonous theory of coal formation and also brought discredit on the idea that coals form a prescribed and definite progression from peat to anthracite. 

A flood is a temporary covering by water of land normally not covered by water. This definition includes floods from rivers, mountain torrents, Mediterranean ephemeral water courses, and floods from the sea in coastal areas and may exclude floods from the sewerage systems. Worldwide, over 65% of the large cities with more than 2.5 million inhabitants are located in coastal areas, deltas, and estuaries and almost 40% of the population of our planet is living within a 100-km-wide coastal strip. In the past, flooding disasters have struck human society all over the world and in the future they may be expected to do so again. Flooding still remains one of the most widely distributed natural hazards in the whole world. 

Fig. 16. Bioaccumulation factor (normalized to organism lipid and sediment organic carbon) as a function number of aromatic rings in PAHs. Mean and standard error of the mean BAFi c for PAHs consists of 2-6 aromatic rings. Each mean represents several PAHs and sediments (sites = 7 for amphipod = 5 for polychaete). [See Table 1 for PAHs and ring categories.] Polychaete (Armandia brevis) and amphipod (Rhepoxynius abronius) individuals were exposed to Raritan-Hudson estuary (New York) sediments for 10 d. See Appendix for BAFioc definition. (Data from Meador et al. 1995.)...

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