So over the past week, we have continued to follow the sampling mission described last time: zig zagging our way over the portion of the Mid Atlantic Ridge called the Ascension Fracture as we make the final push to Ascension Island.
As predicted by Antonio, the currents have shown evidence of a rotation on either side of the ridge, clockwise to the south and counter to the north of the fracture
Another surprise we encountered while crossing over the rift was that on the first crossing, the glider reset underwater once again early on a weekend morning. Unfortunately with these resets, we lose the data from the segment since it was written to the gliders RAM and not saved to the hard drive until the segment is complete.
Then later when we crossed the ridge again, we noticed that as we crossed, the compass began to spin close to when the glider should have been crossing over what is the thinnest part of the earths crust along the ridge, which may have caused a magnetic anomaly that led to the compass freaking out. A strong magnetic field we think could have caused the reset on the first crossing if it was strong enough
However on the third crossing, there doesn't seem to be much of a reaction as the glider neither reset nor had too much of a wonky compass.
As the glider has been out for just under 9 months, the data on our pages has gotten very congested and so John Kerfoot has helped us out creating a new plot of the recent sampling mission, however, the data is a bit spread out for now so we can not make out any patterns just yet. Looking at the old plot however, we can see the continued oscillation of the thermocline, although it has become much smaller than it was weeks ago.
Finally, as we are nearly ready to head west towards the island with a month still left before the planned recovery, Antonio and I have proposed to the group that we will fly the windmill pattern within the 40 mile box to the west of the island, which will keep us in range of the boat just in case anything bad happens.
Force Wind Sea & Honor