This week the NOAA Ship Fairweather is completing her 30-day hydrographic reconnaissance survey in the Arctic. The crew’s personal observations during this successful cruise brings home the importance of measuring ocean depths and updating nautical charts with precise and accurate modern data. Ensign Owen provides Fairweather’s last blog post for this project. – DF
by Ensign Hadley Owen, NOAA, Junior Officer, NOAA Ship Fairweather (S-220)
1200 hours, Sunday, August 26, 2012:55°57.2’N 166°01.2’W, Bering Sea, approximately 100 nautical miles north of Unimak Pass
We are back in the Bering Sea, sloshing around amongst multiple low pressure systems on our way back south to finish out the Fairweather’s 30-day Arctic recon. While it has appeared a lonely transit at times, our AIS (Automatic Identification System) has proved that there are others along this Bering/Chukchi/Beaufort Seas route who will benefit from the updated hydrographic data we are recording.
We have seen more than 50 vessels over the past few weeks, including tugs and towing vessels; cargo ships; fishing vessels; tankers; research ships; U.S Navy and U.S. Coast Guard vessels; and even a couple of small passenger vessels. The ships have ranged from 12 meters to over 200 meters, with drafts of up to 15 meters.
We met mariners with a boat – essential to the region’s economy – whose crew has had frustrations with inaccurate charted soundings. The Greta Akpik is a lightering vessel operated by Bowhead Transport Company. The Fairweather stopped mid-trip outside of Barrow in order to disembark three scientists who were returning home, as well as to pick up stores to provide the remaining crew with food and supplies for the second half of our trip. As the town of Barrow does not have pier facilities, residents depend on the services of shallow-draft lightering vessels to transfer supplies between ships and shore. In casual conversation, the crew of the Greta reported soundings on a chart marked at 30 feet which in actuality read 5 feet on their depth-sounder – a somewhat nerve-wracking discrepancy but not impossible for their shallow-draft vessel. However, this kind of variation can prove a significant deterrent to other maritime traffic looking to enter the region.
Two examples of this “other” traffic that we encountered near Barrow were the 194-passenger Hanseatic and the 165-stateroom The World. Both vessels are considered luxury expedition cruise ships, offering their patrons unique opportunities to visit the world’s last remote outposts. The Hanseatic was on a 27-day trip from Nome, Alaska, to Reykjavik, Iceland. The World is a “privately-owned, residential yacht” for 130 families who collectively chose their vessel’s annual destinations. Both were traveling along the North Slope of Alaska, preparing to transit the Northwest Passage en route to the Atlantic Ocean. In addition to bringing a modest level of tourism to the area, these expedition cruise ships also serve to increase the world’s awareness of the rarity of these remote Arctic Alaskan communities. They mark the beginning of increased and wider interest in the accessibility of the area and the ease with which services can be obtained.
Even with this level of traffic, we are quickly reminded of how much the area’s nautical charts need to be updated, as we transit across a 28 nautical mile square region, south of St Lawrence Island in the Bering — which is totally lacking in soundings. To date, vessels have operated safely by relying on a great degree of local knowledge and nautical good sense. Our recent transit, however, has not only emphasized the degree to which our charts of the area need to be updated, but reminded us of the range of traffic that will benefit from these corrections and additions.
by Lt. Madeleine Adler, NOAA, Navigation Officer, NOAA Ship Ferdinand R. Hassler
Three-dimensional model of the seabed in the vicinity of USS New Jersey (north) and USS Virginia (south) created with Hassler multibeam echo sounder data.
NOAA Ship Ferdinand R. Hassler recently submitted a multibeam echo sounder survey of two sunken World War I era battleships to the Office of Coast Survey. Hassler, which was commissioned earlier this summer, surveyed the site of these two wrecks while transiting through the area during test and evaluation operations in 2011, and has been using the resulting dataset for calibration purposes since then. Although the wreck locations were well known, they had never been surveyed with modern techniques.
The ships are USS New Jersey and USS Virginia, which were intentionally sunk during aerial bombing experiments in 1923. U.S. Army Colonel Billy Mitchell, a pioneer of military aviation, urged the Navy to investigate the effectiveness of aerial bombing against surface vessels. As part of a series of tests, the Navy anchored the two obsolete “White Fleet” battleships off Cape Hatteras in September 1923 to serve as targets. Bombers under Mitchell’s direction sank both ships in short order. The success of these tests had a significant influence on subsequent development of U.S. air power and air defense for naval vessels.
Hydrographic survey systems require thorough calibration and testing before data can be accepted for application to NOAA nautical charts. New Jersey and Virginia rest in water approximately 100 meters deep, making them excellent test targets for Hassler’s Reson 7111 mid-water depth multibeam echo sounder system. Hassler surveyed the wrecks during a trial voyage from Pascagoula, Miss., to Norfolk, Va., in 2011, and the crew used this dataset and others to calibrate the echo sounder. Hassler’s survey systems are now fully operational, and the survey is ready for submission.
Coast Survey will use the survey of USS New Jersey and USS Virginia to update nautical charts of the area, and NOAA’s Office of National Marine Sanctuaries personnel will study it to further their understanding of marine archeology and the seafloor in the vicinity of Monitor National Marine Sanctuary.
NOAA Ship Ferdinand R. Hassler was commissioned on 8 June 2012, and continues to survey mid-Atlantic coastal waters for charting, fisheries and ocean exploration.
Surveyed wreck site (lower right corner) overlaid on Chart 11555. Site is 16 nautical miles southeast of Cape Hatteras, North Carolina.