Alpheus echiurophilus sp. nov. (Crustacea: Decapoda: Caridea: Alpheidae) is described based on material from Japan (Ryukyu Islands) and Vietnam (Nha Trang Bay); an additional, morphologically slightly different specimen from Madagascar (Nosy-Bé) is preliminarily referred to A. cf. echiurophilus sp. nov., awaiting collection of additional material and/or genetic comparison. All specimens of the ...

Interpreting observations of frequency-dependence in backscatter from the seafloor offers many challenges, either because multiple frequencies are used for different observations that will later be merged or simply because seafloor scattering models are not well-understood above 100 kHz. Hindering the understanding of these observations is the paucity of reported, calibrated acoustic measuremen...

the sarghaye-sarnish watershed, with elongated shape and about 70.654 km2 area, is located in south of mashhad. sarghaye and sarnish rivers are the main ones in this watershed. the purpose of this study is to investigate grain size varietions based in sedimentary links and its relation to textural parameters such as sorting, skewness and kurtosis, as well as identification of sedimentary lithof...

B etween 1900 and 2010, the global volume of natural resources used in buildings and transport infrastructure increased 23-fold (1). Sand and gravel are the largest portion of these primary material inputs (79% or 28.6 gigatons per year in 2010) and are the most extracted group of materials worldwide, exceeding fossil fuels and biomass (2). In most regions, sand is a common-pool resource, i.e.,...

The deposition of the instantaneously released sediment into a gravel matrix and the hydraulic resistance induced by the rapid siltation are investigated herein. The experimental results reveal that the depositional patterns of the sediment are governed by the gravel-sediment size ratio, the amount of sediment released, and the seepage flowrate. The observations also indicate that the stable st...

Granulometric, mineralogical and morphological investigation of the sea-bottom sediments in the Grgur Channel has revealed fi ve sediment types, the most frequent of which are muds containing some amount of coarse fractions (sand and gravel). The coarsest fractions are predominantly composed of recent shell fragments. Unexpected well rounded carbonate gravel was found SE of Prvić Island in 83 m...

Analysis of frozen cores of chum salmon egg pockets collected in the fall revealed that spawning activity purged about 75% of the fine sediments Corn the stream bed. The egg pocket was one of four distinct vertical strata detected in the cores. There was an undisturbed layer below the egg pocket and cover and bridge strata above the egg pocket, defined by their particle size distributions. Howe...

It is suggested that in a localized remnant of Kalahari sand at Dufuya, central Zimbabwe, groundwater flows in an integrated pattern inherited from the paleochannel network of the underlying gneiss. Contact springs occur at discrete localities along the Kalahari sand/gneiss boundary and are associated with spring sapping and land surface subsidence. Subsidence is presumed to be due to preferent...