Hello world,
It is day 14th Sunday, and is time for me to update you on what has happened on the ship since the last update.
While I was writing my last post, the ship was just passing through the Bering Straight, and we were about to enter the Arctic circle. Since then, we have continuously traveled northeast up to 75 45N 151 15W, which is almsot as north as the middle Greenland! Woah, that’s pretty north. For the next 430 nautical miles (1 nm = 1.15 miles), the seafloor was between 30 and 40 meters! ONLY 40 METERS! That’s 130′, which is way less than half of the Healy’s full length, 420′. While being mindblown by that fact, we made a pit stop to deploy a NOAA mooring. Because we have expert mooring scientists and technicians onboard, notably chief scientist Peter Worcester and tech John Kemp amongst others, a group of NOAA scientists have ask us to deploy an passive acoustic mooring up here. A mooring has an anchor, a long line the links the anchor to devices to the buoy/s that keep the whole apparatus upright. We have been told that the primary objective of this mooring was to monitor bowhead whale vocolization, but since the hydrophones (underwater microphones) will be recording 24/7, it is expected to record ALL sounds produced underwater. The mooring will be recovered by University of Alaska’s R/V Sikuliaq in several months. After that quick deployment, we proceeded northeast to our stations.
Now, our main project, led by Peter Worcester, is to deploy 6 moorings with scoustic sources and 1 passive acoustic mooring with a ton of hydrophones on it. The 6 moorings will be deployed in a pentagon shape, with 1 mooring source being in the center of the pentagon. The hydrophone mooring will be deployed slightly west of the center acoustic source. Using this acoustic source and hydrophone setup, he wishes to study how sound propagates in the Arctic. What makes sense, but may not be thought of by us who do not study that Arctic, is that sound is affected by the physical properties of the medium is travels through. In water, sound has a very fast velocity (approx. 1400 meters per second), and if the water gets colder, the water becomes denser, and the sound speeds decreases. Once we locate the exact locations of all of the sources and the hydrophones, the scientists can use this to measure the sound velocity in the Arctic. Why is this being studied now? The ice coverage and the water temperature is changing, and it is important to know how the current Arctic deepwater affects sound travel.
Okay, so that’s the cool science that is happening on the ship. We deployed the NOAA buoy and one acoustic source. We traveled further north to our station location furtherest north, but because of slightly excessive winds and ice coverage at our station, we decided to relocate to another station. In the meanwhile, the techs identified that we possibly have a faulty GPS antenna, that is affecting our multibeam (seafloor mapping system)**. We have two antennas that help locate our position for the multibeam system, and since one of them is down, the multibeam is having to depend on a single satellite antenna, which is not ideal but still functions enough. For our mapping purposes, it is critical that we know our exact location so that the seafloor data is relevant. We even have a scientist from the government agency National Geospacial-Intelligence Agency to investigate the quality of our seafloor raw data, because they use it for their hydrographic charts. Other than that, the lab has been a quiet place; I have continuously been shadowing Brandon and Keith as they approach connectivity issues with some of the computers and systems, but everything has been smooth for the most part.
**I wrote that the faulty GPS system was part of the multibeam, but I misspoke. The GPS system associated with the multibeam is working perfectly, but actually the GPS not working well was associated with our MRU (motion reference unit). It is still being troubleshooted for.
The image below is myself redoing the connection between the antenna and the GPS cable. I was up way higher than it looks in the photo.
Photo by Sadie Wechsler