Inside the Jason Control Van!
TRM (Trawl Resistant Mount) – a shallow water OBS (Ocean Bottom Seismometer)
Thursday, July 19th 2012
Before I went to sleep last night, we were having a bit of bad luck. During the final stages of the most recent shallow water recovery of the TRM at site FN05A, we had unfortunately gotten the line attached to the TRM stuck on the ship’s propeller (eek!). With lines breaking and pop-up buoys not responding to signals, these TRM’s are keeping the whole crew on their toes! Luckily however, we were able to save this TRM and successfully cut away the line attached to the propeller. Though not sure whether the line attached to the propeller was okay, we decided to keep moving with the hope that the line would make its way off the propeller on its own.
Right now, I’m glad to report that so far everything seems fine!
Later on, after waking up for my 8am watch, my fellow watch standers and I expected the Jason to be done with its two night dives. However, when Natsumi and I stumbled into the computer lab around 7:45am, a deserted room greeted us. Glancing up at the live video in the lab, we quickly realized that Jason was still in the water. Rushing rapidly to the control van, we learned that Jason was in the middle of its second dive. Fortunately for us, we found the TRM within our first 10 minutes on watch, and the TRM was safely recovered and on board by 10am!
Next, we speed off to a new TRM site, where we hoped that the recovery would go just as smoothly. Regrettably however, the pop-up buoy at the next site didn’t respond to the signal calling for its release. A pop-up buoy, if it functions properly, usually floats to the surface once its signal has been sent. However, if the buoy doesn’t respond to its call, the crew has no way to reach the TRM without sending Jason down to find it. Considering that the Jason team had just recently gone to sleep after their long night of work (The Jason team is currently on a 12hrs on, 12hrs off schedule – working from 8pm to 8am), the Co-Chief Scientists decided to leave the malfunctioning pop-up buoy site to recover some more TRM’s (rather than stick around until the Jason team was awake and ready to spring into action).
Transiting to the next site during lunch, I’m glad to report that we were able to recover the next TRM without any problems! Having a prime view of the whole recovery from the bridge (where the ship is navigated), the Captain explained to Hanna and I that he was taking extra care to position the line attached to the TRM away from the propeller (so as not to repeat what had happened to the TRM line yesterday evening). Next, with one more pop-up buoy recovery to go before the Jason team’s shift, the last TRM’s buoy unfortunately malfunctioned. However, on the bright side, the ship was finally close enough to shore to get cell service! Excitedly calling my family, I described to them the adventures of the day and the exciting things happening on this ship!
Tonight, I’m happy again to report another smooth Jason TRM recovery during my night watch! Now, with two recoveries under our belts, my watch team is calling it a night!
Till next time,
P.S. – What we have called the ACDP thus far, is in fact not an ADCP, but a Knudsen, or bottom profiler.