Preface The expedition ARK XIX/3 with the German icebreaking RV ...

ackscatter value of -37.0dB, -38.9dB, -37.3dB and -41.2dB from west to east. In this
channel the backscatter grey level also correlates to the penetration depth of the
multicorer. However, the easternmost segment of the channel has the lowest dB value
but also the lowest penetration.
In the channel segments 1, 2, and 3; 2, 3 and 2 samples were recovered respectively.
From segment 4 one sample was recovered. The results of the penetration depth are
similar in each of the segments. This shows that the segmentation was properly done and
supports segmentation based on angular backscatter data. Fig. A4.2.2-5 shows the
relation between backscatter and sediment properties. Different grain size is indicated by
colour. Vertical changes in the sediment structure are indicated by a horizontal line. A line
in the middle of the bar means a gradual change in the sediment.
Fig. A4.2-5: Grain size and penetration depth at selected locations. Normalized backscatter and
penetration show a clear correlation. Vertical changes in the sediments are indicated by a
horizontal line. If the line is drawn in the middle of the bar, the sediment changes gradually.
Although this first analysis of the data did not show a close correlation between
backscatter grey level and grain size, the lower dB level could be due to the coarser
material in this shallower part of the channel (segment four). The grain size analyses
indicate a change from coarser material (sand, sandy silt) in the shallower part to finer
sediments in the deeper part of that channel (silty clay, clay). Hence, thegrain size
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