scholarly journals Radiotracer Estimation of Microbial Biomass in Lake Sediment

1985 ◽  
Vol 42 (2) ◽  
pp. 373-379
Author(s):  
Gerald G. Marten
Keyword(s):  
British Columbia ◽  
Microbial Biomass ◽  
Lake Sediment ◽  
Sediment Cores ◽  
Total Biomass ◽  
Biomass Of Microorganisms

The biomass of sediment organisms can be measured by allowing carbon tracer to distribute itself through sediment cores. Application of this method to sediment from Marion Lake, British Columbia, indicated that most of the sediment microorganisms were concentrated in the top 2 cm of sediment, where the total biomass of microorganisms was estimated to be 183 μg C/cm2. The radiotracer estimate compared favorably with independent measurements based on ATP and direct microscopic counts of sediment microorganisms.

The History of Human Impacts in the Clear Lake Watershed ( California) as Deduced from Lake Sediment Cores*

1999 ◽  
Author(s):  
Douglas Nelson ◽  
Alan Heyvaert ◽  
Laurent Meillier ◽  
Jae Kim ◽  
Xiaoping Li ◽  
...  
Keyword(s):  
Lake Sediment ◽  
Human Impacts ◽  
Sediment Cores ◽  
Clear Lake ◽  
History Of

3000-Year paleoseismological record from the region of the 1988 Saguenay, Quebec, earthquake

1998 ◽  
Vol 88 (5) ◽  
pp. 1198-1203
Author(s):  
Ronald Doig
Keyword(s):  
Active Region ◽  
Lake Sediment ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Recurrence Interval ◽  
Pattern Match ◽  
Local Origin ◽  
Organic Rich Sediment

Abstract The 1988, magnitude mb 5.9 (mbLg 6.5) Saguenay, Quebec, earthquake occurred in a region considered to be aseismic, but the epicenter was less than 100 km northwest of the seismically active region of Charlevoix. Lake sediment cores representing some 3000 yr of sediment accumulation contain abnormal silt layers attributed to seismic shaking events prior to the 1988 earthquake. The layers are formed by the relatively rapid settling of the silt portion of the seismically resuspended organic-rich sediment. Cores were obtained over a distance of 120 km, perpendicular to the Saguenay graben structure. Several silt layers are much thicker and more widely distributed than the effect of the 1988 earthquake and are comparable to those observed at Charlevoix that were produced by magnitude 6 to 7 events. The silting events do not correlate between the sampled lakes nor does the pattern match that at Charlevoix, so that the shaking events are interpreted to be of local origin. The recurrence interval for magnitude ≧6 earthquakes ranges from 350 to 1000 yr, in contrast to the roughly 75-yr historical recurrence of earthquakes of magnitude greater than 6 at Charlevoix.

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