Text and photo: Andreia Plaza-Faverola, researcher CAGE; project leader SEAMSTRESS
We started the cruise abiding by the law of the sea (we assisted a smaller ship that was in trouble). Luckily for the crew of the small ship and for ourselves, the weather was nice and the sea calm. Next, we collected the seven seismometers (five from Geomar, two from UiT) that were at the ocean floor since last year. Now it was time to launch the next part of our experiment.
This time we left 10 seismometers at the bottom, eight from AWI and two from UiT, distributed in a faulted region north of the Knipovich Ridge. In average the deployment of each instrument took about an hour. This included a test of the releasers. The releasers were placed in a cage and sendt down to 2000 meters water depth, to check whether they were receiving the signal from the ship and responding with the task they were asked to do (open the hook!, close the hook!, send a signal back to the ship!, etc). Some of the releasers failed to obey in the last minute, almost like a child who refuses to do this and that. So they needed to be replaced (the releasers…). It was a long couple of days for all, in particular for those preparing the instruments to be thrown overboard.
Placing the instruments at sea went smooth. Now we all wait until next year to recover the instruments and hope that they recorded small earthquakes originating from, or somehow related to, faults that show up at the seafloor. These in turn may be related to the opening of the Knipovich mid-Ocean ridge. Since shallow seismicity is not expected in the zone where the instruments sit, what we really are hoping for is that the instruments will record something unexpected.
Towards the end the whales were still with us and the wind was in our favour.