A theory (involving tropical cyclones) on the formation of coarse-grained sand beach ridges in NE Australia

2010 ◽  
Vol 346 (1) ◽  
pp. 7-22 ◽  
Author(s):  
Jonathan Nott
Keyword(s):  
Tropical Cyclones ◽  
Coarse Grained ◽  
Sand Beach ◽  
Beach Ridges ◽  
Coarse Grained Sand

scholarly journals Ejection-velocity distributions from impacts into coarse-grained sand

1999 ◽  
Vol 34 (4) ◽  
pp. 605-623 ◽  
Author(s):  
Mark J. CINTALA ◽  
Lucinda BERTHOUD ◽  
Friedrich HÖRZ
Keyword(s):  
Coarse Grained ◽  
Ejection Velocity ◽  
Coarse Grained Sand

scholarly journals HYDROGEOPHYSICAL DELINEATION OF PROLIFIC GROUNDWATER AQUIFER AROUND STUDENTS’ HOSTELS IN FUPRE CAMPUS, NIGERIA

2020 ◽  
Vol 4 (2) ◽  
pp. 68-72
Author(s):  
Alaminiokuma G.I. ◽  
Omigie J.I.
Keyword(s):  
Electrical Resistivity ◽  
Shallow Aquifer ◽  
Coarse Grained ◽  
Sand Column ◽  
Deep Aquifer ◽  
Current Electrode ◽  
Electrical Resistivity Survey ◽  
Groundwater Aquifer ◽  
Groundwater Supply ◽  
Coarse Grained Sand

Electrical resistivity survey was conducted around Students’ Hostels in FUPRE to delineate prolific aquifer for potable water to serve the teeming population of staff and students. Five vertical electrical soundings (VES) using Schlumberger electrode configuration with a maximum current electrode spread of 300m were employed for data acquisition. WINRESIST software was employed to execute the iteration and inversion processes of computing resistivities, depths and thicknesses of the various layers and the curve types. Results indicate that the area is characterized by 4 distinct geoelectric layers inferred differently at the VES locations. Two potential groundwater aquifer zones are delineated. The unconfined shallow aquifer zones found at VES 1, 3, 4 and 5 locations have shallow overburden depth ranging between 3.7-19.3m and coarse-grained sand columns with thicknesses ranging between 2.8-17.7m while the confined deep aquifer zone found at VES 2 location coincides with deep overburden layer at a depth of 42.6m and coarse-grained sand column with appreciable thickness of 19.1m. These results suggest that boreholes for sustainable groundwater supply around the Students’ Hostels should be sited at VES 2 location and screened at a depth ≥40.0m. However, aquifers at VES 1, 3, 4 and 5 have potentials for groundwater but are vulnerable to contamination. It is recommenced that electrical resistivity and hydrogeological surveys should be conducted at different locations in FUPRE, before any borehole(s) are drilled, to delineate the appropriate aquifer for potable groundwater supply and to avoid possible contamination.

Purification Efficiency of Danish Biological Sand Filter Systems

1993 ◽  
Vol 28 (10) ◽  
pp. 89-97 ◽  
Author(s):  
J. Nielsen ◽  
A. Lynggaard-Jensen ◽  
A. Hasling
Keyword(s):  
Chemical Properties ◽  
Coarse Grained ◽  
Negative Effects ◽  
Sand Filters ◽  
Sand Filter ◽  
Removal Capacity ◽  
Reed Bed ◽  
Anoxic Zones ◽  
Coarse Grained Sand ◽  
Maximum Removal

During an investigation in 1989 on small low technology treatment systems, particularly reed bed and biological sand filter systems in Denmark, it appeared that biological sand filter systems offer several advantages for the treatment of small wastewater sources. These observations gave rise to a new project concerning systematic registration of all biological sand filter systems in Denmark. Besides this registration the aim of the project was to indicate the reliability of these systems concerning removal ability and to give some general guidelines on different circumstances which seem to have positive or negative effects on the removal of particularly ammonium and phosphorus. The paper summarizes the results and experiences that have been collected since the beginning of the use of biological sand filter systems in Denmark in the late 70s. Typical purification efficiencies of 90-95% for BI5, 30-45% for nitrogen and 40-60% for phosphorus were observed. The ripening of sand filters to their maximum removal capacity is often short, within a few months, but longer periods of about 6 months may be required to achieve full nitrification. High nitrogen removal depends on the nitrification processes and also of anoxic zones in the filter with denitrification. The best way to achieve good nitrification is to use coarse-grained sand. The removal of phosphorus is indeed affected by the chemical properties of the sand in question. In ferrous enriched sand it is possible to achieve removal efficiencies of 70-90% of the phosphorus at concentrations of 10-15 mg P/l in the inlet.

The transport and distribution of the river load from the Kacza River into the Gulf of Gdańsk (Southern Baltic Sea, Poland)

2011 ◽  
Vol 40 (4) ◽  
pp. 1-10
Author(s):  
Ewa Szymczak ◽  
Damira Rhode ◽  
Halina Piekarek-Jankowska
Keyword(s):  
Baltic Sea ◽  
Suspended Sediment ◽  
Granulometric Composition ◽  
Coarse Grained ◽  
Bed Load ◽  
Gulf Of Gdańsk ◽  
Southern Baltic Sea ◽  
Gulf Of Gdansk ◽  
Southern Baltic ◽  
Coarse Grained Sand

AbstractThe results of measurements of suspended sediment and bed load carried by the Kacza River into the Gulf of Gdańsk are discussed. The investigations were conducted in the years 2009–2010 at the Orłowo transect and at the mouth of the Kacza River in the Gulf of Gdańsk. The research has shown that the Kacza River discharged about 673 tons of sediment annually to the Gulf of Gdańsk, with 77% being transported as bed load. The granulometric composition of the river load is dominated by coarse-grained sand fractions.

The unique interstitial habitat of a new neritiliid gastropod, Neritilia littoralis

2003 ◽  
Vol 83 (4) ◽  
pp. 835-840 ◽  
Author(s):  
Yasunori Kano ◽  
Tomoki Kase ◽  
Hirofumi Kubo
Keyword(s):  
Large Volume ◽  
Coarse Grained ◽  
Okinawa Island ◽  
Subsoil Water ◽  
Freshwater Streams ◽  
Panmictic Population ◽  
History Of ◽  
Coarse Grained Sand ◽  
Brackish Environment

A new neritiliid gastropod, Neritilialittoralis, lives in a unique, intertidal, subterranean, brackish environment on Amami-ohshima Island, Japan. It lives exclusively on rubble that is embedded deeply in coarse-grained sand whose interstices are filled with a mixture of subsoil water and seawater. Empty shells of this species were also found in tide pools at the foot of limestone terraces on Okinawa Island, where a large volume of karst-related freshwater gushes out. The species is characterized by a very small, white shell and unpigmented skin. Neritilia has previously been found in freshwater streams, rivers, estuaries, and in anchialine and phreatic waters, and the present find expands its range of known habitats and has implications for the history of the invasion of freshwater by neritiliids. The spiral protoconch suggests that the larva of N.littoralis is long-lived, planktotroph and a very effective disperser, and all the individuals collected appear to be part of a panmictic population.

scholarly journals BIOSTRATIGRAPHIC CHARACTERIZATION OF THE CRETACEOUS DEPOSITS OF THE SAN-PEDRO MARGIN OF DRILL HOLES K1 AND K2 OF BLOCK KL: PALEOENVIRONMENT IMPLICATION

2021 ◽  
Vol 9 (11) ◽  
pp. 289-301
Author(s):  
Koffi Chiaye Larissa ◽  
◽  
Djeya Kouame Leger ◽  
Douzo Jolie Wanesse Danielle ◽  
Monde Sylvain ◽  
...  
Keyword(s):  
Water Depth ◽  
Depositional Environment ◽  
Point Of View ◽  
Coarse Grained ◽  
Fine Grained ◽  
San Pedro ◽  
Drill Holes ◽  
Coarse Grained Sand ◽  
Cretaceous Deposits

The KL block studies was carried out the eastern part of the San Pedro margin, it has an area of 2034 km2 with a water depth varying from 500 to 2750 m with two probings (K1 and K2).The objective of this work is to carry out a biostratigraphic and paleoenvironmental study based on the associations of planktonic and palynomorphicmicrofauna in the formations of the KL block boreholes. From a lithological point of view, the base of the boreholes generally comprises alternating limestone and argillite, very fine to fine grained quartz sandstone. Its upper part is overlain by claystoneinterbedded with limestone, silstone and siliceous cemented sandstone and alternating claystone, medium to coarse grained sand and siliceous cemented quartz sandstone. The Albian is determined by the presence of the species Ticinellamadecassiana. The Cenomanian is identified by the micropalaeontological assemblages composed of Globigerinelloides spp., Guembelitria spp., Hedbergella spp., Hedbergelladelrioensis, Globigerinelloides bentonensisandLoeblichella cf. hessi. The Turonian is based mainly on the species Hedbergellaplanispira, Heterohelixmoremani and Whiteinella archaeocretacea. The Early Senonian is characterized by associations of species (Hedbergellasp, Hedbergella cf. delrioensis, Buliminacrassa and Whiteinella baltica) and palynomorphs (Proteaciditestienabaensis, Odontochitinacostata, Odontochitinaporiferaand Tricolpites sp). The roof of the Campanian is known by the association of the palynomorph (Trichodinium castanae) and the microfossil (Gaudryina cretacea) The Maastrichtian is highlighted by the associations composed of species Rzehakina epigona fissistomata, Rzehakina minima, Plectina lenis, Reophax duplex, Reophax pilulifera, Reophax globosus, Gaudryina pyramidata and Afrobolivina afra) and palynomorphic species (Andalusiella gabonensis, Cerodinium granulostriatum and Palaeocystodinium australinium). All the micropalaeontological data coupled with those of the microfaunas make it possible to envisage a depositional environment of the internal platform type with continental influence on an external platform.

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