Good morning! It’s 0314 on board as we are excitedly sitting in the lab after successfully retrieving out first ocean-bottom seismometer (OBS) at 0245 this morning. The engineers are currently taking the device apart in the wet-lab and will be analyzing the data soon! But first, let’s talk about what got us here to this exciting moment.
This spring, under the guidance of Maya Tolstoy, we five undergrads began preparing for our cruise on the Thomas G. Thompson. Although many of us already had a basic understanding of the geological processes at work, we started with a general overview of ocean bottom seismology and eventually progressed to more cruise specific details throughout the semester.
On July 10th at 0830, we were underway. Making our way through a series of draw bridges and narrow ship yards, we motored towards the Ballard Locks. The locks lowered us about 25ft from Lake Union into the Puget Sound. Amongst fog and an ever-curious crowd at the locks, we headed out into the sound where we began our preparations for the retrieval of our first OBS, which we affectionately call M30A.
Preparations included a ship’s safety briefing, a scientific party briefing, a watch standing briefing, and instrument assembly by the engineers and scientists. After all of the meetings were adjourned and watch schedules determined, we hit the racks in hopes of getting a few hours of sleep before our first retrieval. At 0100, Dale and I began our watch in the computer lab for the anticipated retrieval at 0230. We got on-site at 0220 and sent an acoustic signal to the OBS letting it know its time was up. It took about 45 minutes to ascend to the surface from a depth of 1870 meters, but we quickly spotted the flashing strobe and bright yellow floatation off of our starboard bow once it arrived. The captain then positioned the ship so that the OBS could be “hooked” alongside and then a crane was used to lift it on to the deck. At that point, everything had gone exactly according to plan, and soon the data can be extracted from the seismometer. But now we are off to site J59A!