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Seabed Maps Showing Topography, Ruggedness, Backscatter Intensity, Sediment Mobility, and the Distribution of Geologic Substrates in Quadrangle 3 of the Stellwagen Bank National Marine Sanctuary Region Offshore of Boston, Massachusetts

Scientific Investigations Map 3544
Coastal/Marine Hazards and Resources Program
Prepared in cooperation with the National Oceanic and Atmospheric Administration
By:  and 
https://doi.org/10.3133/sim3544

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Abstract

The U.S. Geological Survey, in cooperation with the National Marine Sanctuary Program of the National Oceanic and Atmospheric Administration, has conducted seabed mapping and related research in the Stellwagen Bank National Marine Sanctuary (SBNMS) region since 1993. The area being mapped using geophysical and geological data includes the SBNMS and the surrounding region, which totals approximately 3,700 square kilometers (km2) and is subdivided into 18 quadrangles. The seabed is a glaciated terrain that is topographically and texturally diverse. Quadrangle 3, the subject of this scientific investigations map, has a mapped area of 185 km2 and has water depths that range from about 30 meters (m) on the Stellwagen Bank crest to about 135 m in a basin east of South Ninety Bank, which lies off the eastern margin of Stellwagen Bank. Seven map types, each at a scale of 1:25,000, depict seabed topography, ruggedness, backscatter intensity, distribution of geologic substrates, sediment mobility, distribution of fine- and coarse-grained sand, and substrate mud content. These maps show the distribution of geologic substrates on the southeastern part of Stellwagen Bank, on adjacent banks and basins in deeper water to the east, in the eastern part of Race Point Channel to the south of the bank, and on the northern slope of Cape Cod. Interpretations of multibeam sonar bathymetric and seabed backscatter imagery, photographs, video imagery, and grain-size analyses were used to create the geology-based maps. Data from 309 stations were analyzed, including 279 sediment samples. The geologic substrate maps of quadrangle 3 show the distribution of 21 geologic substrates that represent a wide range of textures, such as rippled sand, immobile sand, immobile muddy sand, sand that partially veneers gravel, and boulder ridges. Mapped substrates are characterized by sediment grain-size composition, surface morphology, substrate layering, the mobility or immobility of substrate surfaces, and water depth range. This scientific investigations map portrays the major geological elements (substrates, topographic features, and processes) of environments in quadrangle 3. It is intended to provide a foundation for research into present and past sediment transport processes in a complex terrain, provide insights into the ecological requirements of invertebrate and vertebrate species that use the various substrates, and support seabed management in the region.

Suggested Citation

Valentine, P.C., and Cross, V.A., 2026, Seabed maps showing topography, ruggedness, backscatter intensity, sediment mobility, and the distribution of geologic substrates in quadrangle 3 of the Stellwagen Bank National Marine Sanctuary region offshore of Boston, Massachusetts: U.S. Geological Survey Scientific Investigations Map 3544, 8 sheets, scale 1:25,000, 30-p. pamphlet, https://doi.org/10.3133/sim3544.

ISSN: 2329-132X (online)

Study Area

Table of Contents

  • Abstract
  • Introduction
  • Methods
  • Map A. Sun-Illuminated Topography and Boulder Ridges
  • Map B. Seabed Ruggedness
  • Map C. Backscatter Intensity and Sun-Illuminated Topography
  • Map D. Distribution of Geologic Substrates
  • Map E. Sediment Mobility
  • Map F. Distribution of Fine- and Coarse-Grained Sand and Boulder Ridges
  • Map G. Distribution of Substrate Mud Content and Boulder Ridges
  • References Cited
  • Appendix 1. Data Layers and Data for Quadrangle 3
Publication type Report
Publication Subtype USGS Numbered Series
Title Seabed maps showing topography, ruggedness, backscatter intensity, sediment mobility, and the distribution of geologic substrates in quadrangle 3 of the Stellwagen Bank National Marine Sanctuary region offshore of Boston, Massachusetts
Series title Scientific Investigations Map
Series number 3544
DOI 10.3133/sim3544
Publication Date April 02, 2026
Year Published 2026
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Woods Hole Coastal and Marine Science Center
Description Pamphlet: v, 30 p.; 8 Sheets: 26.98 x 36.56 inches or smaller; Data Release
Country United States
Other Geospatial Quadrangle 3 of the Stellwagen Bank National Marine Sanctuary region
Online Only (Y/N) Y
Additional Online Files (Y/N) Y
Additional publication details