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

One N-S profile was sampled at a spacing of 50 m. The result is a set of two
temperature curves at 0.25 and 0.55 mbsf. Only one site near the centre of HMMV
shows significantly increased values, at 100 m distance, temperature values are
almost background values (figure B3.1.2-2).
Figure B3.3-2: Temperature profile of
a N-S profile across the centre of
HMMV. Horizontal axis is a
continuous time scale and vertical
temperature excursions represent
station time in the sediment.
B. 3.1.3 Temperature measurements with long gravity corers
Foucher, J.-P., Kaul, N.
On several gravity corer stations the tool is equipped with autonomous temperature
loggers to gain temperature information from greater depth, i.e. down to 10 or more m
below sea floor. From technical consideration, we chose a setting of a 10 m long core
barrel with 9 or 10 loggers attached to it at a spacing of 0.88 or 1 m, respectively.
Nine gravity corers were equipped with loggers and six of them gave successful
readings (for locations, see figure B3.1.3-1, below). We think that failed penetrations
are due to gas hydrates. On the other hand the centre of the mud volcano yielded
“over-penetration”, i.e. the instrument penetrated completely and the overall
penetration depth had to be reconstructed from mud line marks on the deep sea
cable. In summary we got 6 temperature-depth profiles, covering depth intervals from
almost 0 to 16 mbsf (see figure B3.1.3-2).
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