Nya försök att upphämta långa sedimentprofiler från havsbottnen

Kullenberg, B.; Fromm, Erik

doi:10.1080/11035894409445691

Cited by 12 publications

(7 citation statements)

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“…The use of a piston, derived from a method employed in terrestrial clay sampling (Olsson 1925;see also Olsson 1938), in combination with an adapter permitting tripping and free-fall from just above the bottom (Kullenberg 1944(Kullenberg , 1945(Kullenberg , 1947(Kullenberg , 1955 has become a much-used underwater technique. However, such piston corers also have serious drawbacks.…”

Section: Choice Of Sampling Devicementioning

confidence: 99%

Quantitative sampling of soft-bottom sediments: problems and solutions

Blomqvist¹

1991

Mar. Ecol. Prog. Ser.

157

112

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ABSTRACT. Since the pioneering attempts to obtain quantitative soft-bottom sediment samples at the beginning of this century, many different devices for sampling soft bottoms have been presented. Most techniques, however, yield semi-quantitative samples only. For studies dealing with certain aspects of microlayering, freezing in situ seems to be a good method. In more general studies, quantitative samples appear to be best obtained using instruments based on the coring principle. Improper handling or faulty design of the conng device, however, results in unrepresentative samples. Major factors in b~a s are (1) loss of surficial sediments. ( 2 ) redistribution, resuspension and loss of enclosed sediment, ( 3 ) core shortening, and ( 4 ) repenetratlon. Frictional drag and consequent smearing against the coring tube is also a potential source of error General design features improving the reliability of sampling are a supporting stand and, when dealing with open corers, a n unimpeded water flow through the sample compartment. Box corers appear best suited for sampling certain macrofauna and sediments of coherent and silty/sandy character. Adequately designed and properly operated tube corers are the most versatile instruments at present. A general concern, however, is that coring tubes enter and penetrate the sediment carefully and slowly. Under favourable conditions, a n open-barrel gravity corer can b e used for sampling the unshortened upper layer, in combination with a larger box corer and subsequent piston-coring technique for sampling the underlying layers. When sampling under less favourable conditions, or when extreme care is required, the corer must be based on a structure with a supporting stand, which permits the device to settle on the bottom before the coring tubes enter the sediment. Mounting an underwater video camera as a standard on such devices is recommended since lt enables visual inspection and recording of each sampling. Other tested means and promising improvements in instrument design to improve sampling reliability are also discussed.

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Section: Choice Of Sampling Devicementioning

confidence: 99%

Quantitative sampling of soft-bottom sediments: problems and solutions

Blomqvist¹

1991

Mar. Ecol. Prog. Ser.

157

112

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“…Accordingly, we regard the logarithm of the mean annual varve thickness as the appropriate measure for further comparisons. Kullenberg and Fromm (1944), Granar (1956) and Cato (1987) demonstrated earlier the good correlation between maximum daily discharge in spring (early summer floods) and the corresponding annual varve thickness. For years 1909-1935, Cato (1987 obtained a value of r = 0.68, when he correlated the varve thickness of core PC 3 (see Figure 7) against maximum daily mean discharge.…”

Section: Annual Varve Thickness and Monthly Discharge (Ad 1909-50) Comentioning

confidence: 93%

“…The upper part is often composed of a lower thicker, dark part and an upper, thinner, light-grey part which occasionally contains sand and gravel (Cato, 1987). Grainsize measurements carried out by Kullenberg and Fromm (1944) indicate that the coarse-grained part of the varves was deposited during high water periods (spring and early summer), while the fine-grained layers with a high content in organic material and sulphur iron deposited over a longer timespan, probably during low-water periods and oxygen-free bottom waters (autumn, winter). However, the data set contains only the total annual thickness of each varve in each core (in mm) (Figure 7) and thus does not allow for a seasonal resolution.…”

Section: Annual Varve Thickness and Monthly Discharge (Ad 1909-50) Comentioning

confidence: 99%

“…The measurements and correlations were carried out by Cato (1987), who also published varve records recovered earlier by Granar (1956), Fromm (unpublished data) and Kullenberg and Fromm (1944). Corings were made along a c.15-km section of the estuary (see Cato, 1987, for a detailed location of the cores).…”

Section: Annual Varve Thickness and Monthly Discharge (Ad 1909-50) Comentioning

confidence: 99%

“…Core location and year of fieldwork Years covered Published by GC 491 Nyland 19781978-1949Cato (1987) GC 3 Nyland 19781973-1944Cato (1987) GC 8 Nyland 19781972-1940Cato (1987) GC 2 Nyland 19781971-1927Cato (1987) GC 9 Nyland 19781957-1922Cato (1987) PC IV Nyland 19521949-1850Granar (1956) PC 2b Nyland 19431942-1926Kullenberg and Fromm (1944) PC 3 Nyland 19781935-1791Cato (1987) PC I Nyland 19521933-1850Granar (1956) PC F Nyland 19451930-1414Cato (1987) PC D Nyland 19451926-1494Cato (1987) PC E Nyland 19451924-1414…”

Section: Introductionmentioning

confidence: 99%

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The climatic significance of clastic varves in the Ångermanälven Estuary, northern Sweden, AD 1860 to 1950

et al. 1998

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Multiple regression analyses were applied to decipher the correlation between monthly discharge, precipitation and temperature records and annual varve-thickness data from river Ångermanälven north-central Sweden between 1860 and 1950. Over the whole 90-year period we found generally a strong correlation between spring/summer precipitation and annual varve thickness. However, there are clear indications that precipitation during the months of January and March-May was more important for the formation of varves in the early part of the twentieth century, while January, March, April and June seem to have been more significant during the later part of the nineteenth century. Monthly temperatures and annual varve thickness, on the other hand, did not show any significant correlations over the whole 90-year period, but, when split into 30-year periods, a dependence of varve thickness on October (1862-90) and March (1919-50) temperatures could be observed. Our results show that it is important to test each specific varve record against instrumental data sets before any conclusions can be drawn in terms of precipitation and/or temperature dependence. They also emphasize the necessity to correlate varve-thickness records against long instrumental series in order to detect any changing forcing mechanisms.

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