ISSN:
1573-5117
Keywords:
boundary mixing
;
nepheloid layer
;
resuspension
;
internal seiches
;
vertical modes
;
particles
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The effect of internal seiches on horizontal hypolimnetic bottom currents and on the stationary well-mixed benthic boundary layer (BBL) induced by these currents was studied for 2 weeks in a small prealpine lake using thermistor strings, an acoustic current meter and a CTD (C: conductivity, T: temperature, D: depth) equipped with a transmissometer. 150 profiles of temperature, conductivity and transmissivity taken during two days clearly indicate the existence of a well-mixed BBL 2 to 7 m thick. This is the result of intense mixing in the zone of high shear above the sediment associated with seiching motion. The concentration of suspended or resuspended particles, mainly of organic nature, within the BBL, was 2 to 4 times greater than that measured directly above the BBL. Resuspension is thought to be associated rather with high-frequency burst-like currents with measured speeds ranging up to 7 cm s−1 than with the average bottom current speed of about 2 cm s−1.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00005731
Permalink
