Bathymetry and backscatter intensity of the sea floor of the Historic Area Remediation Site in 1996, 1998, and 2000

Surveys of the bathymetry and backscatter intensity of the sea floor of the Historic Area Remediation Site (HARS), offshore of New York and New Jersey, were carried out in 1996, 1998, and 2000 using a Simrad EM1000 multibeam echosounder mounted on the Canadian Coast Guard ship Frederick G. Creed. The objective of the multiple echosounder surveys was to map the bathymetry and surficial sediments over time as dredged material was placed in the HARS to remediate contaminated sediments. Maps derived from the multibeam surveys show sea-floor bathymetry, shaded-relief bathymetry, and backscatter intensity (a measure of sea-floor texture and roughness) at a spatial resolution of three meters. The area was mapped by the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers and with support from the Canadian Hydrographic Service and the University of New Brunswick.