Survey discovers exposed natural gas pipeline south of Mobile Bay

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.

Side scan sonar of exposed pipeline

NOAA navigation manager Tim Osborn worked in concert with the contractor to report the danger to the Department of Interior Bureau of Ocean Energy Management (BOERME), and to the U.S. Coast Guard District 8 Headquarters Waterways Section. Tim and the contractor were able to provide precise positions, imagery, and other resources.

The Coast Guard is warning mariners to avoid the area.

The pipeline delivers over 1.3 billion cubic feet of natural gas per day to the 20 million residents of Florida. In addition to posing a threat to the marine environment, an accidental rupture of the pipe could cause a national economic impact in losing a huge supply of energy.


Learn more about hydrographic surveys and side scan sonar.

Meet the men and women of today’s Coast Survey

LCDR Ben Evans commands NOAA’s newest survey vessel, the Ferdinand R. Hassler

Since President Thomas Jefferson asked for a survey of the coast in 1807, Coast Survey has been the nation’s trusted source for nautical charts covering the coastal waters of the U.S. and its territories.

Nature is never static, especially in systems as powerful as ocean coastlines. Human activities are constantly reshaping vast areas, both on shore and underwater. Today, NOAA’s hydrographic surveys continue to traverse U.S. waters, measuring the ocean depths of the constantly shifting sea floor, acquiring data on changing shorelines, and searching for underwater dangers to navigation.

This blog will feature the work being done by the men and women of NOAA’s Office of Coast Survey to protect life and property, on ships and on shore. Visit often, and learn how these NOAA Corps officers, physical scientists, cartographers and technicians produce the precise and accurate navigational products that mariners trust.