Geological interpretation of a low-backscatter anomaly found on the New Jersey continental margin

An enigmatic low-backscatter, acoustic anomaly occurs on the New Jersey continental margin between Hudson and Wilmington Canyon channels. The presence of the low-backscatter anomaly, as seen with 6.5- and 12-kHz data, indicates a change in the physical properties of the seafloor or near sub-surface. Analyses of seafloor and sub-surface acoustic data with previously collected sediment cores suggest the low-backscatter feature corresponds to an outcrop of older strata uncovered by erosion and non-deposition by the Western Boundary Undercurrent (WBUC). The decrease in backscatter strength is enhanced by the presence of gas in the sub-surface sediments found in the buried Chesapeake Drift.

► We hypothesize the geological causes of a seafloor low-backscatter anomaly. ► The low-backscatter anomaly is an erosion feature caused by bottom contour currents. ► Sediment gas from the Chesapeake Drift causes the decrease in backscatter strength.