How do ocean explorers know where to look when they investigate and document the historical secrets of the deep? Well, archaeological expeditions use a myriad of modern surveying technologies. Recently, when NOAA’s Monitor National Marine Sanctuary was investigating a World War II underwater battlefield site, they called on a surveying expert with NOAA’s Coast Survey to assist.
Before we get to the Fairweather logs, we need to update the last post, NOAA Ship Fairweather zigzags her way to accurate and precised depth soundings. Cmdr. Crocker reports that the “normal” zigzagging won’t start until they head further north, starting near Point Hope. It was not planned for the trip to Kotzebue, and he would have run a straight course if he could have. This log by Ensign Hadley Owen explains why they zigzagged earlier than planned, as well as what they are doing for their first scientific project. We apologize for the error in the last post. -DF
Fairweather Log Entries, August 2 and August 5
by Ensign Hadley Owen, NOAA, Junior Officer, NOAA Ship Fairweather (S-220)
The officers, scientists, and crew of the NOAA Ship Fairweather have started their 30-day Arctic reconnaissance survey, and you can watch their progress on NOAA’s ship tracker website.
The diagram on the right shows the corridor Fairweather will travel during this survey project. (Fairweather’s survey corridor is shown in green.) The ship will zigzag back and forth within that corridor, checking actual depth soundings against measurements acquired during the 20th century or even earlier. (See the vintage of the depth measurements in the Aug 1 blog post, Arctic reconnaissance survey checks old soundings to prioritize future surveys.)
NOAA’s Office of Coast Survey, Alaska, and the nation’s economic vitality have been intertwined for 145 years. We strengthen that bond on August 1, as NOAA Ship Fairweather begins a reconnaissance survey to the northernmost tip of the Alaska’s Arctic coast. Fairweather will check soundings along a 1,500 nautical mile coastal corridor from Dutch Harbor, Alaska, to the Canadian border. (At least, we hope Fairweather can go all the way to the Canadian border… The ice cover is a little stubborn this summer, and may not recede sufficiently for safe passage. CMDR Jim Crocker, the ship’s commanding officer and chief scientist of the party, will keep us updated through the coming weeks. Watch this blog site for Fairweather updates!)
Coast Survey’s Navigation Response Team 4 is conducting a year-long survey of the sea floor in the Port of Houston and Galveston Bay navigational areas, re-measuring ocean depths and searching for dangers to navigation. Coast Survey will use the data to update future nautical charts to help mariners protect lives and increase shipping efficiencies. Recently, the team also found an opportunity where they could support marine archeological preservation.
Last week, the navigation team worked with federal and state partners who help us understand the rich history – and the secrets of human sorrows – lying on the seafloor. In collaboration with NOAA’s Flower Garden Banks National Marine Sanctuary and the Texas Historical Commission’s Marine Archeology Division, the navigation response team — with the State Marine Archeologist onboard — re-mapped the location of two historically significant wrecks. (Some of the data was collected under an antiquities permit, as Texas requires for investigating historic shipwrecks in state waters.)
Ocean floors are always changing. Coast Survey’s hydrographic surveys are intended to find and measure those changes. Often, we need to do more than that, as shown by a recent survey of the seafloor in Alabama coastal waters.
A Coast Survey contractor ‒ David Evans and Associates ‒ found a large high-pressure natural gas pipeline that had been uncovered and was lying exposed, as shown by this side scan sonar image. The exposed 36-inch diameter pipeline, pressured to 2,100 psi, posed a threat to navigation and the environment.