Everyone was elated and relieved when the temperature observatory was successfully installed on Monday evening, completing one of the main objectives of JFAST. In about a week's time of Expedition 343T ('T' for technical) we were able to drill the borehole to 855 meters below seafloor and install the temperature sensors across the plate boundary - something that we could not accomplish in over 50 days of operation a few months ago.

"Everything in life is luck"
Donald Trump "In my experience, there's no such thing as luck"
Obi-Wan Kenobi, in Star Wars by George Lucas.

There are many steps in the deployment of the observatory, such as preparation of the underwater camera system, running the long pipe to the ocean floor, setting the wellhead, borehole re-entries, underwater instrument releases, borehole drilling, casing installation, temperature instrument programming. During the original expedition last April and May, it seemed at almost every step of the way there was some problem or delay. Also there were many concerns about operations in nearly 7000 meters of water, for which Chikyu and other IODP platforms had no experience. This time in July, things were quite different and each procedure went surprisingly smoothly. The reasons are better weather, gained technical experience from the previous attempts, and a lot of good luck.

"Luck can only get you so far"
Hermione Granger, in Harry Potter and the Half-Blood Prince by J. K. Rowling. "The winds and waves are always on the side of the ablest navigators"
Edward Gibbon

Experience helps. Detailed knowledge of the actual drilling conditions and instrument performance, which are gained from experience, contribute immensely to success. Actually, CDEX engineers know this and told me so last year. At the time, they felt that all the technical challenges of the project could be met, it was just a matter of how many tries it would take and if there was enough time. We were very fortunate on this project that additional expedition days were provided so that we had the opportunity to try again. Also, it is a great credit to the drilling engineers and planning staff at CDEX that they were able to solve the many problems. Finally, luck often swings the balance between failure and success and we got lucky this time (I am getting more superstitious for these kinds of things).

"Those who have succeeded at anything and don't mention luck are kidding themselves"
Larry King

The deployment of the temperature sensors has been an exciting technical accomplishment, but the real scientific results come when we see the recorded data. The next challenge will be in several months when we try to extract the instrument string from the borehole, using a remotely operated vehicle (ROV) in the very deep water. These data should help us understand the huge amount of slip that occurred in the 2011 Tohoku earthquake.

Release of the instrument string from the drill pipe, which was the final step of the temperature observatory installation at 18:15 on July 16 (photo by Patrick Fulton).

More photos from the expedition at
http://www.jamstec.go.jp/chikyu/exp343/e/gallery.html