Data Acquisition - Phase I
Leaving port in Seattle, the Langseth spent two days in transit to the survey site. As much as we’d like to sit back and enjoy our trek into the horizon by watching “The Office” and the occasional whale, we had some preparation to do. We used our time wisely and practiced processing seismic data and adjusting to our staggered 12 hour work schedules. Since there are only six of us, we need all hands on deck to make sure everything runs smoothly in the lab.
Lamont-Doherty Scientists and Technicians waiting for data
Huston we have a…Whale?
The Langseth has a boastly array of 36 airguns that use pressurized air to create a massive air-bubble that travels to the sea floor. In our case, we are shooting to OBS’s deployed by the CCGS Tully. These will record rays that reflect and refract through sediment layers which we can process later to interpret oceanic structure.
Given the right tools—creating an underwater sea-bubble seems easy enough, right? Think again. I was surprised by the variation of internal and external factors that cause complications in data collection. Our first hiccup occurred four hours into shooting, as a hose malfunction in the compressor room caused us to shut down a string of guns for about an hour.
To address the elephant in the room (or whale in the bathtub?) whales are our biggest threat to data collection in the daytime. When a whale is sighted, by law we are required to stop shooting to ensure protection of endangered species. In hopes to mitigate data loss, Lindsay and Ben consulted the scientists on the CCGS Tully and concluded to do a giant U-turn and resample the missing section. Often when the lab phone rings, we all hold our breath hoping it wasn’t a whale sighting.
Humpback whale courtesy of PSO Lillia
Amidst these minor setbacks, our science team has been working with everyone to get the data we need. At the time of writing this post we, have successfully deployed our 15km streamer and will be entering Phase II. More to come soon!
— Lazaro Garza
The original line we intended to shoot, that was broken into different sections due to whale sightings. You can see the Langseth’s path and the giant U-turns we made in our route.