U.S. Geological Survey Open-File Report 2007-1373
High-Resolution Geologic Mapping of the Inner Continental Shelf: Cape Ann to Salisbury Beach, Massachusetts
Title Page / Table of Contents / List of Figures / Introduction / Maps / Data Collection/Processing / Interpretation / Summary / Acknowledgments / References Cited / Appendix 1 / Appendix 2 / Appendix 3 / Appendix 4 / Appendix 5
Figure 3.4. Map showing acoustic-backscatter intensity offshore of northeastern Massachusetts between Cape Ann and Salisbury Beach. Backscatter intensity is an acoustic measure of the hardness and roughness of the seafloor. In general, higher values (light tones) represent rock, boulders, cobbles, gravel, and coarse sand. Lower values (dark tones) generally represent fine sand and muddy sediment. Offshore data (green dashed outline) were collected by SAIC in 2004 and nearshore data (red dashed outline) were collected by USGS in 2005.
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