We left Cape Canaveral (Florida) last Saturday, June 17, 2023. It took us roughly 5-days to transit to our survey site, which lies about 60 miles (~100km) south of the Cayman Islands. This is the site where scientists from Scripps Institute of Oceanography placed 40 Ocean Bottom Seismometeres (OBS) last Decemeber. The sensors sat on the ocean floor for approximately 6 months gathering data on the movement of the Earth under the seafloor. This site is located over two techonic plates that slowly move away from each other, increasing the elevation of the surrouding seafloor.
The 40 OBSs will be retrieved one at a time by sending a burn signal to the instrument, which releases the OBS from the bottom. They take anywhere from 50 min – 2.5 hours to rise, depending on the depth. Once the OBS reaches the surface, we use its radio beacon, its red flag, and its white light, to locate it. The boat pulls up next to it, where scientists attach at least two lines to it. One of the lines is attached to the winch, which is used to lift the OBS onto the deck.
My job, as marine tech, is to operate the winch, lifting the OBS out of the water and onto a platform on the deck. It is fairly easy to use with only two levers; one lever moves the A-frame in and out, and the other moves the line up and down. Once on deck, we can retrieve its inner data and move onto the next OBS. We will continue in this fachion until all the OBSs have been retrieved. The other marine tech and I operate on 12-hour shifts (2:00-2:00) so that we can work around the clock with the scientists. We hope to have all OBSs onboard by Wednesday (6/28).
