Sorry for the delay in blog posts. Ever since we started heading for the Bight Fracture Zone, I’ve been busy with the onboard work, and it’s been quasi rough. That is all behind us now, as we are safely tied up to the dock in Reykjavik, Iceland. Cruise kn221-02 is officially over, and my colleagues and I are heading out for a celebratory drink at The Dubliner (weird name for a pub in Iceland). The ship’s engines are turned off, and the incessant vibration and noise they caused has mercifully ceased. I’m hoping for a good night’s sleep tonight.
Our survey of the Bight Fracture Zone revealed a deep current of high-salinity water escaping from the eastern North Atlantic through this crack in the mid-Atlantic ridge. This flow had mainly been in our imaginations until now — based on an assemblage of circumstantial evidence. Some completely unexpected results also presented themselves, including a complicated pattern of warm and cold currents near the surface.
We are psyched to have confirmed this new pathway for the deep currents in the Great Ocean Conveyor. Not only is this an important discovery for describing the geography of the oceans, it has implications for how ocean waters mix. Over the past couple of decades, we have learned that currents flowing over a rough sea floor (with ragged hills and deep valleys) generate a lot of turbulence and the water gets quite mixed up. This changes the current’s water properties, and the mixing is also an important part of the whole energy budget for the oceans. The current we discovered showed evidence of lots of mixing–we will be studying the results in more detail over the coming months.
As far as we know, we are the first to make these detailed measurements of the currents through this gap. This is the kind of oceanography that I love best. It’s very exciting to know that you are the first to find something that has never been observed before, even right here on our own planet. At our end-of-cruise science de-briefing meeting yesterday, we spent half of the time discussing these new results from the Bight Fracture Zone, which we had collected in just one day! Research is that way–you can plan and plan, but still get surprises.
So here concludes my OSNAP cruise log. I plan to continue making weekly blog posts on the general theme of the challenges of being a visually impaired scientist and how I try to meet those challenges. I already have a few topics in mind–revisiting the topic of physical versus intellectual competence, and access to scientific graphs and equations. I welcome your comments and questions on these or any related topics.