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

Pogonophora field
O2, H2S (mM)
Pogonophora sediment, 4/7/03
0.25
0.2 O 2
8
7.8
0.15 pH
7.6
0.1
7.4
0.05
H 2 S
0
7.2
-50 -0.05 0 50 100 1507
depth (mm)
pH
O2 (mM)
Pogonophora sediment, 4/7/03
0.005
0.004
0.003
0.002
0.001
0
-50
-0.001
0 50 100 150
depth (mm)
Profiles in Pogonophora sediments. The pH sensor broke at 75
mm depth. The irregularities at 30-40 mm depth may be caused by
collisions against hard surfaces, resulting in piezo potentials. The
right panel shows two oxygen profiles scaled between 0 and 5 µM.
Clearly oxygen penetrates over 50 mm. No H 2 S was detected.
The sediments are made coherent by the abundant chitine tubes of the worms that
extent to more than 30 cm below the sediment surface. The microsensor
measurements were difficult, and all sensors eventually broke during the penetration.
However, several profiles were obtained. Interesting is that no sulfide was detected
and that oxygen penetrated over 50 mm deep. This was not observed in the
sediments from the Beggiatoa fields or in the center area. This must be s result from
ventilation by the worms.
Lander measurements (list of deployments)
date depth Lat N Lon E sensors area
1 28/6/2003 1286 72.0.22 14.43.11 pH, redox,
O 2 , H 2 S
Some
Beggiatoa
2 30/6/2003 1287 72.0.159 14.43.887 pH, T, O 2 , Worms
H 2 S, pH,
Ca 2+ 2-
, CO 3
3 5/7/2003 1278 72.0.387 14.43.603 pH, T, O 2 , Worms
2-
H 2 S, CO 3
4 6/7/2003 1283 72.0.115 14.43.496 pH, T, O 2 , Beggiatoa
2-
H 2 S, CO 3
5 9/7/2003 1252 72.00.334 14.43.691 pH, T, O 2 ,
2-
H 2 S, CO 3
Central
area, border
worms
6 11/7/2003 1252 72.00.148 14.43.630 pH, T, O 2 , Beggiatoa,
2-
H 2 S, CO 3
7 14/7/2003 1290 71.59.03 14.45.44 pH, T, O 2 ,
2-
H 2 S, CO 3
disturbed
reference
site
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