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= Wikipedia Editing Project: Nepheloid Layer =

Draft
Nepheloid layer or nepheloid zone is a layer of water in the deep ocean basin, above the ocean floor, that contains significant amounts of suspended sediment. It is from 200 to 1000 m thick. The name comes from Greek: nephos, "cloud". The particles in the layer may come from the upper ocean layers and from stripping the sediments from the ocean floor by currents. Its thickness depends on bottom current velocity and is a result of balance between gravitational settling of particles and turbulence of the current. The formation mechanisms of nepheloid layers may vary, but primarily depend on deep ocean convection. Nepheloid layers can impact the accuracy of instruments when measuring bathymetry as well as affect the types marine life in an area. There are several significant examples of nepheloid layers across the globe, including within the Gulf of Mexico and the Porcupine Bank.

Formation Mechanisms
A surface nepheloid layer (SNL) may be created, due to particle flotation, while intermediate nepheloid layers (INL) may be formed at the slopes of the ocean bed due to the dynamics of internal waves. These intermediate nepheloid layers are derived from bottom nepheloid layers (BNL) after the layers become detached and spread along isopycnal surfaces.

Deep ocean convection has a prominent effect on the distribution of nepheloid layers and their ability to form in certain areas of the ocean, such as the northern Atlantic Ocean and the northwestern Mediterranean Sea. Nepheloid layers are more likely to form based on patterns of deep ocean circulation that directly affect the abyssal plain. This is largely through the disruption of accumulated sediments in areas that deep ocean currents interact with. Convection currents that disturb areas of the ocean floor such as those that circulate via ocean gyres also affect the concentration and relative sizes of the suspended sediments, and by extension the area's corresponding biotic activity.

Bathymetry
The existence of the nepheloid layer complicates bathymetric measurements: one has to take into account the reflections of lidar or ultrasonic pulses from the upper interface of this layer, as well as their absorption within the layer. Interference from the thick layers of suspended sediments can ultimately product inaccurate results concerning submarine topography.

Marine Life
Depending on the characteristics of a particular nepheloid layer, they can have a significant impact on marine life in the area. The layers of sediments can block natural light, making it difficult for photosynthetic organisms to survive. In addition, the suspended particulates can harm filter feeding organisms and plankton by blocking their gills or weighing them down.

Gulf of Mexico
A prominent nepheloid layer exists in the Gulf of Mexico extending from the delta of the Brazos River to South Padre Island. The layer of turbid water can begin as shallow as 20 meters and is caused mostly by clay run-off from multiple rivers. The silty bottom of the gulf also contributes to the high turbidity. Due to the blockage of light by this nepheloid layer, algae and coral are sparse, resulting in an animal-dominated community. This community is largely composed of infauna and consists of a detrital-based food chain. Many species of polychaete worms, amphipods, and brittle stars inhabit the benthic surface and can also be accompanied by some secondary consumers such as flounders, shrimp, crabs, and starfishes.

Porcupine Bank
A prominent nepheloid layer exists also in the Porcupine Bank. Geographically, the nepheloid layers are more detectable and prominent along the Porcupine Bank’s western slope. Both the bottom and intermediate nepheloid layers form due to a myriad of factors such as internal tides, waves, and subsequent bottom erosion. The intermediate nepheloid layer can also manifest by breaking off from the bottom layer, and the water column above the area in which the bottom nepheloid layer forms is marked by significant differences in temperature, density, and salinity.

Evaluating Content
All of the information in the article is relevant to the topic of the Nepheloid Layer, and the only distractions were the relatively frequent use of more specific, complicated terms that were not already defined (such as “lidar” and “bathymetry”), meaning that in order to read and fully understand the article, one has to navigate to other pages multiple times. None of the content provided is out of date, however more information could be added about the Porcupine Bight, as that section is especially brief and uninformative compared to the section covering the Gulf of Mexico. I believe that the amount and level of detail in the article as a whole could also be improved. The scientific information that is presented is accurate and clearly presented, but as previously mentioned, it does include linked jargon that could be confusing to the average reader.

Evaluating Tone
The general tone of the article is neutral, as none of the presentation of the information suggests any inclination toward a particular opinion or position. Although the information is sparse in some parts of the article as opposed to others, the lack of content it is not indicative of any biases.

Evaluating Sources
There are only three listed sources, one of which provides a link, as the other two are not web-based sources. The link source is operational, and each source supports the informational claims provided in the article. The sources are a glossary of geology and two scientific journals, which each appear to be neutral and unbiased. While there are appropriate references throughout the article, they do seem sparse when compared to the total amount of information presented, so perhaps more references or sources are needed for each fact.

Evaluating the Talk Page
There are no conversations on the talk page at all, so there are no ongoing discussions about the representation of the topic. However, the page does provide insight into the purpose of the article, claiming that the article is part of the scope of the Oceans WikiProject, which is aimed at improving the coverage of oceans, seas and bays by Wikipedia. It is also part of the WikiProject Limnology and Oceanography, which seeks to improve the coverage of inland bodies of water and other marine environments through neutral, informational articles concerning related topics. Under both of those projects, the article has been rated Stub-Class on the quality scale and Low-Importance on the importance scale.

Additional Sources Found
Biscaye, Pierre; Eittreim, Stephen (1977). “Suspended particulate loads and transports in the nepheloid layer of the abyssal Atlantic Ocean”. Marine Geology. 23 (1-2): 155-172. https://doi.org/10.1016/0025-3227(77)90087-1

Diercks, Arne-R; et al. (2018). “Scales of seafloor sediment resuspension in the northern Gulf of Mexico”. Elem Sci Anth. 6 (1): 32. http://doi.org/10.1525/elementa.285

Hays, James D. (1970). Geological Investigations of the North Pacific. Geological Society of America. ISBN 9780813711263. https://pubs.geoscienceworld.org/books/book/130/

Hunkins, Kenneth; et al. (1969). “Nepheloid layers and bottom currents in the Arctic Ocean”. Journal of Geophysical Research. 74 (28): 6995-7008. https://doi.org/10.1029/JC074i028p06995

Madron, X. Durrieu De; et al. (2017). “Deep sediment resuspension and thick nepheloid layer generation by open-ocean convection”. Journal of Geophysical Research: Oceans. 122 (3): 2291-2318. https://doi.org/10.1002/2016JC012062

McCave, Nick I. (1986). “Local and global aspects of the bottom of the nepheloid layers in the world ocean”. Netherlands Journal of Sea Research. 20 (2-3): 167-191. https://doi.org/10.1016/0077-7579(86)90040-2

McCave, Nicholas I. (1978). Sedimentology. Dowden, Hutchinson & Ross, Inc. ISBN 9780879331528. https://link.springer.com/referenceworkentry/10.1007%2F3-540-31079-7_144

Mcgrail, David; Carnes, Michael (1983). “Shelfedge Dynamics and the Nepheloid Layer in the Northwestern Gulf of Mexico”. The Shelfbreak. 33 (1): 251-264. https://doi.org/10.2110/pec.83.06.0251

Thorpe, Steve; White, Martin (1988). “A deep intermediate nepheloid layer”. Deep Sea Research Part A. Oceanographic Research Papers. 35 (9): 1665-1671. https://doi.org/10.1016/0198-0149(88)90109-4