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.
by Ensign Hadley Owen, NOAA, Junior Officer, NOAA Ship Fairweather (S-220)
1200 hours, August 12, 2012: 70°38.7’N 162°06.6’W, approximately 22 miles north of Icy Cape, Alaska’s North Slope
In 1963, the town of Point Hope (68° 21’N 166°46’W) – a small, ancient, and archeologically-significant Inupiaq community on Alaska’s North Slope that remains at present a largely native village – narrowly avoided the creation of an artificial harbor by underwater hydrogen bombs. Part of “Project Plowshare,” the planned creation of a deepwater harbor by thermonuclear power was intended to demonstrate the peaceful use of nuclear power for construction purposes. It was opposed by Native American communities, scientists in the state, and the Episcopalian church across the United States. The protest has been credited as one of the first government projects successfully challenged on the grounds of its potential environmental impact.
Point Hope is just one example of an Arctic Alaskan community for which an increased understanding of the regions oceans and near-coastal areas will prove relevant. From the bathymetry of the coastal region, to the chemical composition of its waters, and the characteristics of its benthic community, studies will document changes in the region due to increased exposure and vessel traffic. The NOAA Ship Fairweather’s current Arctic reconnaissance trip continues to offer that rare opportunity in environmental science – the establishment of “baseline” characteristics of a largely untouched region from which to monitor potentially imminent changes.
In 2008, the USCG Cutter Spar conducted a preliminary hydrographic survey around Point Hope (and other areas), which determined that strong currents in the area were contributing to large shifts in the coastal bathymetry (underwater topography). Sandy sediment and shallow depths, as well as the high level of coastal erosion, have resulted in a significantly changeable nature of the region’s seafloor. Point Hope was one area of interest for this summer’s investigation; on August 8, our ship-based reconnaissance survey of the spit of land’s projection into the ocean showed differences from the area’s charted depiction.
While NOAA’s Office of Coast Survey interest in updating our hydrographic understanding of this region of the Arctic has driven this voyage, we were happy to welcome in Kotzebue a trio of scientists whose work overlapped with and supplemented our own mission. Dr. Doug Dasher, an environmental scientist at the University of Alaska Fairbanks, has had an ongoing interest in Point Hope and related environmental radioactivity studies. He and Terri Lomax, from the Alaska Department of Environmental Conservation, are on board as part of a large-scale survey of biological and chemical trends in the waters of the Arctic Chukchi Sea. Under the Alaska Monitoring and Assessment Program (AKMAP), they are using a stratified random sampling plan over a large area to get the “big picture” of a marine area’s health. Their work supports the U.S. Environmental Protection Agency in their national Aquatic Resource Survey of the nation’s waters.
Also onboard is an aquatic toxicologist from NOAA’s National Center for Coastal Ocean Science (NCCOS), Dr. Ian Hartwell. His path crossed with Dr. Dasher’s several years back in Kachemak Bay on Alaska’s Kenai Peninsula (south of Anchorage), where they were both conducting similar research to their present study. Dr. Hartwell’s work is part of NCCOS’ Coastal Ocean Assessment, Status and Trends (COAST) Program, which conducts biological, physical, and chemical assessments of habitats affected – or potentially affected – by contaminants.
Together, they are paying particular interest to a 25 to 30 nautical mile corridor offshore in the Chukchi Sea. The corridor stretches between the Arctic Ocean’s deep-water oil leases, currently being researched and developed by international oil companies, and the largely subsistence native communities of Alaska’s North Slope. The forward-looking exploration of our Fairweather cruise meshes well with AKMAP’s and NCCOS’s goals of defining and describing the relatively untouched environment of the coastal North Slope. In light of increasing maritime traffic, AKMAP and NCCOS hope to monitor potential contamination and help to proactively address future environmental impact upon this still largely untouched Arctic region.
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.)
“With the often-shifting sediment around here, there are periods of covering and uncovering, so archeologists like to periodically map historically significant wrecks to see what’s changed,” explained Nick Forfinski, the navigation response team’s leader. “We were ‘in the neighborhood,’ surveying for maritime commerce, and we were able to obtain up-to-date images of the wrecks while we were here.”
The steamship City of Waco is one of the historical wrecks that Forfinski’s crew was asked to survey. The steamship burst into flames and sank on Nov. 8, 1875, and 56 people died. The sunken ship was ordered to be demolished in 1900, to protect navigation in the area.
“The collaboration between NOAA experts and the Texas Historical Commission brings a unique combination of expertise and resources to learning more about the hidden history in the Gulf of Mexico,” said Texas State Archeologist Pat Mercado-Allinger. “We are grateful to the NOAA Team for this opportunity to remap this historically important shipwreck.”
Forfinski’s team captured some fascinating images of the City of Waco, created from data they gathered during last week’s hydrographic survey.
This image was created from data acquired by NRT4′s multibeam echo sounder. NOAA hydrographic survey units use multibeam echo sounder systems to acquire full (and partial) bottom bathymetric coverage, to measure depths over critical items such as wrecks, obstructions, and dangers-to-navigation, and for general object detection.
This image was created from data acquired by NRT4’s side scan sonar. A side scan creates a “picture” of the ocean bottom. For example, objects that protrude from the bottom create a light area (strong return) and shadows from these objects are dark areas (little or no return), or vice versa, depending on operator preference.
Using hydrographic surveys for multiple purposes, like “piggybacking” wreck mapping on to a navigation safety project, makes for smart resource sharing. It positions America for the future while helping to preserve its past.