International Dredging Review

International Dredging Review

The USS Niagara a steam-powered and sail-powered frigate launched in 1856 and commissioned in 1857 was a Civil War blockade-runner and escort which also played a role in helping to build the first transatlantic cable. With the arrival of new steel-hulled frigates the Niagara was retired stripped of most of its armament and scuttled in 1897 in Boston Harbor.

A team from the University of Massachusetts (UMass) Boston led by Professor Allen Gontz coastal geologist and geophysicist in collaboration with Vic Mastone the state underwater archaeologist and the Massachusetts Board of Underwater Archaeological Resources has set out to locate and eventually preserve this wreck. The overall objective is to have the site designated as an underwater archaeological preserve and listed on the national historic register.

A site that holds high potential for wreck was located in Boston Harbor by a range of geophysical and geological tools including IXSEA’s MAGIS magnetometer a sidescan sonar and sub-bottom profilers which respectively detects the presence of metal in the wreck produces an image of the seafloor and penetrates through the seabed to reveal sedimentary sequences using sound.

“These tools allow researchers to see through the bottom of the seafloor and analyze the different composition sediments. This technology is integral to successful analysis as visibility is very limited in the harbor” said Gontz

Magis a high resolution high speed data collection marine magnetometer detects metallic objects on the seafloor or buried in the sediment and using Dynamic Nuclear Polarization (DNM). It measures the earth magnetic field and its variations (mines shipwrecks cables containers localization archaeology) in this case the wreck of the USS Niagara. The RV Looney the vessel used to locate the wreck used the Magis as a towed system which is both easily deployed and adjustment-free.

To date MAGIS has been used for a range of applications from mapping of buried objects to pipe and cable route survey and even mine hunting. Used in conjunction with Ixsea’s DELPH MAG LOCATOR it is a real-time and batch objects mapping tool with magnetic filtering producing 2D magnetic field intensity maps in real time.