On calm days, you could almost forget that you are in the
middle of the ocean. Its sunny and
calm outside, and everything is stable inside. People get lax and leave cups and other items on table tops
unsecured and unattended. And then
some big swells come, and we all remember why chairs are tied to tables,
furniture is nailed down to the deck and we use bungie cords and sticky pads to
keep computers and other gear in place. Today we are experiencing swells up to
5 m high, in which the ship has rolled up to 25 degrees. Unsecured items (including people in
chairs!) are rolling all over the lab.
Meanwhile, we are also crossing the Gulf Steam, which poses
it own challenges to our gear. Fishermen are particularly concentrated here,
and today we deviated 10 km off of our profile to avoid fishermen and their
gear. The currents are also
pushing our seismic streamer around.
In the ideal case, the streamer extends straight behind the vessel and
quietly rides 9 meters below the water surface. The currents today have pushed it to the side by 70 degrees
from the ideal track, and the swells generate noise on the hydrophones. However, even though conditions may not
be ideal, it is essential that we collect data here for our science goals. We
think that there are thick accumulations of frozen magmas beneath the Earth’s
surface here that formed when the supercontinent of Pangea broke apart to form
the Atlantic Ocean. So we shall
push ahead!
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| Annotated screen capture from our navigation system showing the ship, the streamer, our intended profile and our deviation. |
Donna Shillington from the R/V Langseth
