USGS Studies in Long Island Sound:
Geology, Contaminants, and Environmental Issues

Because of its inaccessibility, the sea floor is remotely mapped with geophysical equipment that can provide detailed images of the bottom and its underlying geology. The geophysical data produced for Long Island Sound includes high-resolution seismic reflection, gravity, and sidescan sonar.

Figure 1. Section of a high-resolution seismic reflection profile collected from Long Island Sound with a boomer seismic system. Subbottom profiles can be used to interpret the geologic history of the basin.

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Figure 2. The air-free gravity anomalies in Long Island and Block Island Sounds.

Gravity

Link to gravity data in USGS Open-File Report 00-304.

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Figure 3. Image showing a continuous coverage, sidescan sonar mosaic of New Haven Harbor. This survey shows one of nine sites that were mapped to study critical habitats in Long Island Sound.

Sidescan Sonar

Link to Sidescan Sonar data, which includes cruise reports, sample locations, and digital mosaics.

For full-resolution sidescan mosaics, refer the to GIS and Archives page.

Interpretive Reports:

• Branford
• Bridgeport
• Enhanced Imagery
• Falkner Island
• Fishers Island Sound
• Hammonasset
• Milford
• New Haven
• Niantic Bay
• Norwalk
• Roanoke Point
• West-Central LIS

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Figure 4. Trackline map showing the location and coverage of various seismic-reflection surveys in Long Island Sound.

Seismic Reflection

Link to high-resolution seismic-reflection data in USGS Open-File Report 02-002.