Mail Buoy - July 5, 2007

Hey you guys, we've been counting down the days to this mission and love the pics and video - thank you!! Here are some questions:

The first one is from Liberty aged 11: How heavy is Oden?

The next question is from Saomai aged 7: How deep do you anticipate the ice to be where you will drill and how thick is the thickest ice that Oden will have to break through?

My question is do you expect the life forms you find to be in any way related to the ones found at the hydrothermal vents in the Pacific or Atlantic Oceans? If so, why?

Thank you.
Sophie, Liberty, Saomai
Salford, England

ANSWERS:
Liberty: Oden weighs 9,438 tons, according to its master, Mattias Peterson. Fully loaded with fuel, however, it displaces about 12,000 tons.

Saomai: Bertil Larsson, our meteorologist and ice expert on board, says the average thickness of Arctic Ocean ice is 3 meters. But it is rarely average, which is why the icebreaker’s officers and helicopter pilots spend so much time searching for easier routes through thinner ice and looking to avoid areas with thicker ice. When ice floes are squeezed together, for example, they form thick ice ridges that must be avoided. The thickest ice Oden has broken was 6 meters, but that was around Antarctica, near the other pole.

Dear Sophie,

Thank you for your question. If the life forms at hydrothermal vents in the Arctic Ocean follow the same pattern as those for regular (non-vent) deep-sea animals, then I expect the animals living on the Gakkel Ridge to be more closely related to Atlantic mid-ocean ridge vent fauna, which would include groups of mussels, shrimp, anemone, and crab species. Given that there is more of a deep-water connection between the Arctic Ocean and the Atlantic (compared with the Pacific), this may well be the case.

But the Arctic and Atlantic Oceans have exchanged relatively deep water only in the last 20 million years—perhaps not long enough to bring similar animal species together. The Gakkel Ridge lies at even deeper depths that in places remain unmixed with Atlantic waters. So Arctic vent fauna could be completely different from all other fauna.

What makes this an interesting question as well is the fact that species that live on the shallow-water Arctic shelf are mostly different from those found in the deep waters. So it could be the animals at the vents on the Gakkel Ridge have evolved in the Arctic for tens of millions of years isolated from other oceans, and therefore may have a unique evolutionary history. If so, they may not be more similar to either the Atlantic or Pacific. By the end of this cruise, I hope I'll be able to tell you which expectation was the right one. Thank you for your question.

Tim Shank

[Back to top]