By Ensign Brittany Anderson, Junior Officer, NOAA Ship Thomas Jefferson
After a quiet winter at home port, the NOAA Ship Thomas Jefferson completed her sea trials this week in preparation for the 2013 field season.
Each year, prior to departing for working grounds, the Thomas Jefferson transits to the Chesapeake Bay to perform tests on the ship’s and launches’ systems and hydrographic survey equipment. Crews conduct numerous tests to check the accuracy and precision of multibeam echosounders, side scan sonar, and the sophisticated suite of programs that process all the data. Additionally, this is an opportunity to ensure the safety of the vessel and her crew by performing numerous safety drills and readdressing safety standards and operating procedures.
This is a screen capture of the simultaneous multibeam and side scan coverage of an obstruction used to verify the NOAA Ship Thomas Jefferson’s imaging and bathymetric sonars.
But it wasn’t all just tests and drills. During her transit, the Thomas Jefferson also deployed a GPS tide buoy to make real-time tides more accurate and efficient for the region.
Jack Riley and Brian Murray from Coast Survey’s Hydrographic Systems and Technology Programs Branch assist with GPS tide buoy deployment.
Now that the vessels and equipment are ready for the season and the crew has their sea legs back, the NOAA Ship Thomas Jefferson will be returning to the Northeast this year to further update nautical charts for critical shipping and transportation regions.
by Ensign Brittany Anderson, Junior Officer, NOAA Ship Thomas Jefferson
The NOAA Ship Thomas Jefferson wrapped up her field season last week.
After 193 days away from home, the hydrographic survey vessel completed 14, 768.9 linear nautical miles of survey. This covered 352 square nautical miles of area in Long Island Sound and Block Island Sound. Due to this work, 38 dangers to navigation (DTONs) were issued, protecting maritime traffic in the area.
Additionally, the Thomas Jefferson was in prime position to respond to the devastation caused by Hurricane Sandy in October and November. The U.S. Coast Guard requested assistance from NOAA after New York Harbor was closed to all traffic, preventing crucial goods and services from reaching the citizens of New York City. The Thomas Jefferson and her two launches ran 170.74 linear nautical miles of side scan sonar and multibeam echo sounder operations (MBES), while also surveying 53.82 linear nautical miles of object detection MBES.
Thomas Jefferson has returned to homeport for the winter. On November 9, after an exceedingly successful field season, the ship and her crew arrived at NOAA’s Marine Operation Center – Atlantic in Norfolk.
See WAVY-10 TV coverage of the Thomas Jefferson arrival at Norfolk, with some great explanations of their work responding to requests for help following Hurricane Sandy.
Also see earlier posts, Thomas Jefferson finds two divers in Block Island Sound and Thomas Jefferson mapping Long Island Sound.
The Ferdinand R. Hassler and Thomas Jefferson are rafted together at NOAA’s Marine Operation Center – Atlantic.
How many geospatial products can be developed by one seafloor mapping project? As a phased-in project for Long Island Sound shows, a strong collaboration among diverse groups of researchers and technology developers can integrate temporal and geospatial data sources to produce dozens of products. In addition to updating NOAA’s nautical charts, ongoing collaborations in Long Island Sound will create products that depict physical, geological, ecological, geomorphological, and biological conditions and processes – all to balance the development of new ocean uses while protecting and restoring essential habitats.
In 2011, the Long Island Sound Program (representing a partnership between the State of Connecticut, State of New York, Connecticut and New York Sea Grant, and the U.S. Environmental Protection Agency) requested assistance from NOAA. They asked for help in providing management and technical expertise; acquiring data; and developing products. They required key temporal and spatial information about seafloor conditions in the Sound. They needed bathymetry and backscatter, and biological and physical observational and sampling data, to produce all the products needed by governments, industry, academia, and the public.
Coast Survey already had plans for NOAA Ship Thomas Jefferson to survey in Long Island Sound, to acquire new bathymetry for chart updates. With some adjustments to survey areas and project parameters, a mutually beneficial partnership was formed for long-term seafloor mapping of Long Island Sound habitats over the next several years, as an integrated ocean and coastal mapping project.
This summer, Thomas Jefferson conducted hydrographic surveys in the mid-Sound area of Stratford Shoal and vicinity, extending from New York on the north shore of Long Island to the Connecticut shoreline.
“Ocean floors are amazingly dynamic, and we have to chart those changes to provide precise and accurate navigational data for today’s maritime economy,” explained Cmdr. Lawrence Krepp, commanding officer of the Thomas Jefferson and the ship’s chief scientist. “Our data is used to update NOAA’s nautical charts, but the hydrographic information can also be used to support a number of non-navigation uses, ranging from benefits to fisheries management to support of regional ocean planning efforts like this.”
This digital terrain model, showing bathymetry in Long Island Sound, was created from Thomas Jefferson depth soundings.
This image is a digital terrain model that indicates the water depths in surveyed areas. In its final form, it will be geo-referenced to latitude and longitude. To produce this DTM, a NOAA Corps hydrographer, Lt.j.g. (sel) Anthony Klemm loaded Thomas Jefferson’s billions of depth soundings into an algorithum, powered by CARIS’s CSAR technology. By laying out a grid, and then using CUBE – combined uncertainty bathymetry estimator – Klemm is able to visually depict higher resolution depth measurements in shallow water, where the shapes on the seafloor may be navigationally significant, with resolution gradually decreasing as the depth increases.
Digital terrain models are useful for many environmental management activities. In this collaboration, seafloor topography products, like this DTM, will be the foundation for building products that address benthic habitats and other environmental conditions.
NOAA hydrographic survey vessels are valuable assets for search and rescue operations, as experienced crews use their knowledge of tides and ocean currents to develop science-based search patterns. Last month, two divers found out just how valuable NOAA’s expertise can be. — DF
Report submitted by Ensign Brittany Anderson, NOAA Ship Thomas Jefferson
On the morning of August 26, 2012, NOAA Ship Thomas Jefferson was conducting routine hydrographic survey operations south of Block Island. At 0904 hours, a distress call was made on the very high frequency (VHF) radio to the Coast Guard Station. The caller reported two divers lost in the water at Southwest Ledge, a popular recreational point off Block Island. The coordinates were a mere seconds north of the Thomas Jefferson.
A third diver was on a private boat with no VHF radio. He hailed the fishing boat Captain Ron, and that boat called the U.S. Coast Guard, Sector Long Island Sound. The third diver continually returned to the water to search for the two missing divers.
At 0907, the Coast Guard reported via VHF that one of their vessels was on its way, but was 25 minutes out. Cmdr. Larry Krepp, commanding officer of the NOAA Ship Thomas Jefferson, contacted the Coast Guard and informed them of our location and ability to assist in the search for the missing divers. Numerous additional lookouts were called to the bridge to search all points off the ship. At 0908 our ship stopped logging hydrographic survey data, and we retrieved our moving vessel profiler from the water. We calculated the current set and drift from Southwest Ledge and began search lines in the vicinity of the divers’ expected location.
The divers’ initial location is indicated at Southwest Ledge. The red arrows indicate Thomas Jefferson’s search lines, and the red circle shows where the divers were retrieved.
Ensign Brittany Anderson, Ensign Anthony Klemm, Ensign Andrew Clos, Lt. Cmdr. Denise Gruccio, and Cmdr. Lawrence Krepp kept a heavy lookout on all sides. Chief hydrographic survey technician Peter Lewit and physical scientist James Miller updated the expected location of the divers based on current set and drift calculations. Able seaman Tom Bascom was at the helm, steering the course to search for the individuals. At approximately 0930, the Coast Guard rescue vessel arrived on scene and made contact with the third diver. At 0952, Lt. Cmdr. Gruccio spotted the two divers broad off the port beam at a bearing of 282° PGC (per gyrocompass.) We reported the position and distance to the Coast Guard rescue boat on scene; they promptly followed our pointing and bearing to the divers. They safely retrieved the two divers at 0955.
After receiving word from the Coast Guard that the divers were safe and our services were no longer needed, we came about to our survey course. We continued our hydrographic survey operations, relieved and pleased that our training and hydrographic knowledge gave us the ability to find the divers quickly and safely.
The U.S. Coast Guard picked up the two divers, after they were found by NOAA Ship Thomas Jefferson. (Photo by ENS Brittany Anderson.)
NOAA Ship Thomas Jefferson is one of the most technologically advanced hydrographic survey vessels in the world. Equipped with high-resolution seafloor echo sounders, the 208-ft. Thomas Jefferson and its 36-person crew maps the seafloor in support of Coast Survey’s nautical charting mission.
NOAA Ship Thomas Jefferson