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Centre for Geobiology

Day 21 - 15 July

The wind and wave conditions made it too difficult to take any last sediment cores.

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Position: 73°N 8°E
Temperature:   5.6ºC
Wind speed:  14-16m/s
Wave height: 3.7m
Visibility:  moderate
Weather:  foggy conditions

Through the night though, we were able to continue with our systematic CTD work taking water samples down to 3300m along the length and breadth of the rift valley. The CTD samples are tested for their methane and hydrogen contents. Researchers kept the gas chromatography apparatus working constantly – no sleep for the geochemists.

The CTD water samples will also be analysed for their helium isotope composition. The results will tell us how much of the helium present in the water comes from the mantle deep in the earth. This will give us information about the amount of hydrothermal activity in this area and suggest something about how many or how large possible hydrothermal vents might be in the region. Current research results suggest that the volume of water streaming out from hydrothermal vents around the world is about 25% that of the volume entering the oceans from river systems. This hydrothermal vent water, thus has a significant impact on oceans. Hydrothermal activity is an important fundamental process on earth.

The CTD results reveal another methane anomaly about 15km northeast of our primary target area. It seems fairly certain that there is hydrothermal activity at several locations in this region. Unfortunately the ROV has been irreparably damaged by the high pressure so we cannot study this latest result in more detail, and it is just about time for us to set course for Bergen.

We have shown that Norway has some unique and interesting geological features on the sea floor in this area some several thousand metres deep. There are almost certainly some hydrothermal vents and we have seen glimpses of some amazing ecosystems. This cruise has provided some tantalizing hints of fascinating discoveries that will have to wait for another summer!