BOSCORF shares MSCL-S logging procedures and best practise guidance

BOSCORF has revised its working procedures for gathering data on all sediment cores analysed at the facility including new sediment cores accessioned into the collection.  BOSCORF aims to log all sediment cores using the MSCL-S (Geotek Multi Sensor Core Logger – Standard) prior to splitting.  This ensures that the best quality data is captured from the sediment cores.  Physical property datasets are highly requested, however if the data is not captured soon after sediment core collection the loss of data quality can be significant.  The sensors rely on a full core liner of wet sediment for accurate measurement.  Sediment cores begin to dehydrate from the point of collection, therefore the analysis should be performed before the significant loss of pore water.

Download BOSCORF MSCL-S Operating Procedure

BOSCORF has produced an in-house guide to best practise for operating the BOSCORF MSCL-S.  It includes descriptions of new measures adopted by our operators such as, a time efficient approach to logging multiple short cores within a single logging session and performing replicate sample runs.  The inclusion of logging a replicate section multiple times throughout the course of a single day permits the assessment of reproducibility, and provides assurance to scientific users that they are receiving the high quality data from this instrument.

Image 1: Figure showing the same core section analysed at different temperatures throughout the same day. Rep 1 was analysed as the first section of the days logging, when the lab temperature was 16°C. Reps 2 and 3 were analysed after the logger had been operational for several hours and had warmed to 18°C. On average the difference in observed magnetic susceptibility is 8 SI, however the trends remain consistent across all three replicate runs.
 

BOSCORF invites comments on these procedures from other MSCL-S operators with the aim of developing an international best practise procedure documenting the methodology for gathering reliable and reproducible data. The method of sediment core preparation and the process of logging sediment cores through the MSCL-S is complex, and should be fully understood by all MSCL operators and data users.

Image 2: The use of a way up marker for the cores has led to substantial increases in data quality. For analyses in BOSCORF, cores are kept the same way up whilst unsplit from delivery to analysis. This ensures consistency across the core data set, and that fluids are not disturbed more than is necessary prior to analysis on the MSCL-S. The effect of disturbance can be most clearly observed in the density data. This figure shows the same core section, which contains a series of turbidites, run in four back to back replicate runs at the same temperature. For the first three runs, the marker dots were all facing upwards, representing the orientation in which they have been stored. For the 4th replicate run, the core was rotated by 90° prior to being place on the logger, and run at this orientation. The difference in data quality is considerable, with substantial loss of signal, and loss of all features detected within the core for the first three replicates.
 

We would welcome comments or suggestions from the MSCL-S user community to improve our practise and data quality, if you would like to provide comments or have a query relating to this document, please get in touch.

 

If you are interested in collecting MSCL data at our facility or to request MSCL data we may already hold for repository sediment cores, please get in touch with the BOSCORF team at boscorf@noc.ac.uk.

 

Many thanks to John Roberts for his input into improving BOSCORF’s operating procedures, and for the detailed training delivered at BOSCORF.

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