OBS in the Pacific Day 7

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Day 7 .
As promised yesterday, we have a guest writer on the blog today! We all know what this really means…. I got lazy and just copied our Lamont blog for continuity purposes. She did a great job though, so enjoy!
Saturday, July 14th 2012
This morning I woke up to calmer waters than the ones I had fallen asleep to (last night I felt as if I was on a roller coaster that was going around and around in continuous choppy circles). Feeling a bit more tired than usual, Natsumi (my roommate, who is a graduate student from Brown University studying Seismology) and I woke up around 7am for our 8am watch. Breakfast on the ship is served starting at 7:15, and it is customary for watch standers to try and eat first so they can go relieve the current watch standers a bit early. Eating our breakfast quickly, Natsumi and I headed down to the watch room to relieve the 4-8 watch standers, Hanna and Astrika. Since we had left our watch at midnight, the ship had been surveying, a term used to describe the active mapping and imaging of the seafloor. This ship is recording this data using the Mutlibeam and ADCP for Chris Goldfinger, a scientist interested in examining this data for past evidence of great earthquake rupture in the Cascadia region.
On our watch, Natsumi, Cheng (a graduate student from UC Berkeley studying Seismology), and I continued to log every thirty minutes as the ship surveyed around site J33B. At noon, next on our agenda was to deploy another TRM OBS (Trawl Resistant Mount Ocean Bottom Seismometer) with the aid of the Jason ROV (Remotely Operated Vehicle). Once we were officially back on site, the OBS and Jason team began preparing to deploy the OBS just as Dale and John (the 12-4 watch standers) came to relieve us at 12. Eating a quick lunch with Natsumi, I headed up to the upper deck to watch the next OBS deployment. This next deployment was special because it presented us with the unique opportunity to place our LDEO TRM OBS (Lamont-Doherty Earth Observatory) next to a Scripps TRM OBS. Having been deployed for the past year, the Scripps OBS is scheduled to be recovered in about a week. Thus, if our LDEO OBS team, with the help of the Jason team, were able to place our OBS next to their OBS, it would provide the rare opportunity to compare a week’s worth of data from the different OBS’s.

Back on the upper deck of the ship, quite an audience had accumulated to watch the deployment of the next TRM OBS. Armed with cameras, we all waited for the action to begin! The plan for this deployment was for the TRM OBS to be placed in the water, attached to the ship, and then attached to Medea (Jason’s counterpart), who would carry the TRM to the seafloor were Jason would then takeover and place the LDEO TRM OBS next to the Scripps TRM OBS.

Luckily, as we all were waiting for the deployment to begin, a shark appeared off the back of the ship. This made my second marine mammal sighting in two days (last night a bunch of dolphins swam by the ship)!! Maya (Maya Tolstoy), co-chief scientist from LDEO, explained to those of us up on the upper deck about how people aboard NOAA (National Oceanic and Atmospheric Administration) research vessels used to be able to go swimming off the ship during what were called ‘swim calls’, but that once in the tropics someone was attacked by a shark and since then swimming has been banned off NOAA ships.

Finally, with the shark off in the distance, the deployment began at last. Up on the deck, we all watched as the TRM was slowly lifted off the back of the ship and placed in the water. With only minor delays, the deployment of the TRM OBS, Medea, and Jason all went very smoothly. But now began the long wait until the Jason and the TRM OBS reached the seafloor. Retreating below to watch a live stream underwater video from Jason control van, I found myself struggling to stay awake. After downing my third cup of tea for the day, I finally decided that I really needed a nap in order to be awake for my watch later in the day.

After my nap, I learned that the deployment had been a success! Thanks to Jason team, the LDEO TRM OBS was placed next to the Scripps TRM OBS. Finding myself with a couple of hours to kill before my watch at 8pm, I headed off to dinner and then decided to go visit Barry and Adrianne on the front deck. Barry, a Wildlife Biologist, and Adrianne, a Marine Mammal Biologist, are our resident Marine Mammal Observers on-board. The two of them stand outside for most of the day scanning the open water with binoculars for signs of marine life. Today I was lucky to be up there with them when a Fin Whale appeared right off the starboard side of the ship! Three marine mammal sightings in two days. Sweet!
Later on my night watch, we were all set to deploy the next TRM OBS in the same way we had done it earlier in the day (right next to another Scripps OBS). However, last minute the plan changed. Instead of going ahead with what we had done earlier to deploy the OBS, the engineers on-board decided to try out a new deployment method on our TRM (a design based on Jason’s testing elevator).
Walking out on the back deck of the ship to see what was happening, I learned that this new design method involved stringing together most of the floats on-board into one massive flotation device. This large string of floats (with hopefully enough positive buoyancy to counter the weight of the TRM) would then be attached to the TRM OBS and lowered off the ship. This last minute change occurred because the engineers hoped that this new design would allow the TRM to float more gently (fingers crossed that all of the calculations have been done correctly) to the bottom of the seafloor. If this new deployment method works, the plan is to send Jason into the water to make sure that the TRM lands properly upright on the seafloor. If so, the next step is to locate the second Scripps TRM OBS and have Jason place our LDEO TRM OBS next to it. However, since it is now past 12 and my watch is over, you will have to find out from the next blogger what happened to our TRM OBS!
Goodnight!
Caitlin

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