Evaluation of Stokes Settling Equation for Variable Density Aggregates.

• Main Authors: Carder,K L, Steward,R G
• Other Authors: UNIVERSITY OF SOUTH FLORIDA ST PETERSBURG DEPT OF MARINE SCIENCE
• Format: Text
• Language: English
• Published: 1984
• Subjects: Hydrology; Limnology and Potamology; Optics; *Clay; *Holography; *Sediment transport; River currents; Density; Porosity; Particles; Suspended sediments; Thermoclines; Microstructure; Clay aggregates; Aggregate settling; Sea ice
• Online Access: http://www.dtic.mil/docs/citations/ADA140878; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA140878

Holographic measurements of clay aggregates settling through a density/viscosity gradient revealed that the aggregate pore waters are flushed, affecting the aggregate density and settling speed. The flushed pore waters provide a low viscosity conduit in which subsequent particles settle as much as 25% faster than they would in the surrounding fluid. This conduit is holographically recorded due to its reduced refractive index relative to the surrounding medium. Regions where this phenomenon may play an important role are at river mouths and in shelf/slope density-gradient environments for clay aggregates, and in sea-ice-melt regions and in the microstructure of the thermoclines for low-density biogenous particles. (Author)