Geology topics

K. Y. McMullen

Publications and source records attributed to K. Y. McMullen.

22 records · Page 2Linked to original sources

USGS2008

Sidescan-sonar imagery and surficial geologic interpretations of the sea floor in central Rhode Island Sound

The U.S. Geological Survey (USGS) has been working with the National Oceanic and Atmospheric Administration (NOAA) to interpret the surficial geology of areas along the northeastern coast of the United States. During 2004, the NOAA Ship RUDE conducted Hydrographic Survey H11321 in Rhode Island Sound. This sidescan-sonar and bathymetry survey covers an area of 93 km? located 12 km southeast of Brenton Point, RI in water depths of 28-39 m (fig. 1). The purpose of this report is to delineate sea floor features and sedimentary environments of this area in central Rhode Island Sound using sidescan-sonar and bathymetric data from NOAA Survey H11321 and seismic-reflection data from a previous USGS field study (Needell and others, 1983a). This is important for the study of benthic habitats and provides a framework for future research. Prior work in this area includes the mapping of surface sediments and surficial geology. McMaster (1960) collected sediment samples from Rhode Island Sound and Narragansett Bay and mapped our study area as having a sandy sea floor. In addition, one sample of sand from the National Ocean Service (NOS) Hydrographic Database came from a location in the northeast part of our study area in 1939 (fig. 2; Poppe and others, 2003). McMaster and others (1968) used seismic-reflection profiles to map the locations of a cuesta of Cretaceous sediments crossing Rhode Island Sound and post-Cretaceous drainage channels. Knebel and others (1982) identified sedimentary environments in Rhode Island Sound using sidescan sonographs. Needell and others (1983b) studied the Quaternary geology and mapped the structure, sedimentary environments, and geologic hazards in Rhode Island Sound using sidescan-sonar and seismic-reflection data. Sidescan-sonar and bathymetric data from NOAA Survey H11320, which overlaps the far eastern edge of our study area, was interpreted to consist of basins surrounded by a moraine and bathymetric highs composed of till with areas of rocks, sand waves, hummocks, glaciolacustrine erosional outliers, small scarps and elongate hills (fig. 1; McMullen and others, 2007). Some of those features extend into this study area.

Rhode Island↗

USGS2008

Interpolation of reconnaissance multibeam and single-beam bathymetry offshore of Milford, Connecticut

This report releases echosounder data from the northern part of the National Oceanic and Atmospheric Administration (NOAA) hydrographic survey H11044 in Long Island Sound, off Milford, Connecticut. The data have been interpolated and regridded into a complete-coverage data set and image of the sea floor. The grid produced as a result of the interpolation is at 10-m resolution. These data extend an already published set of reprocessed bathymetric data from the southern part of survey H11044. In Long Island Sound, the U.S. Geological Survey, in cooperation with NOAA and the Connecticut Department of Environmental Protection, is producing detailed maps of the sea floor. Part of the current phase of research involves studies of sea-floor topography and its effect on the distributions of sedimentary environments and benthic habitats. This data set provides a more continuous perspective of the sea floor than was previously available. It helps to define topographic variability and benthic-habitat diversity for the area and improves our understanding of oceanographic processes controlling the distribution of sediments and benthic habitats. Inasmuch as precise information on environmental setting is important for selecting sampling sites and accurately interpreting point measurements, this data set can also serve as a base map for subsequent sedimentological, geochemical, and biological research.

Connecticut↗

USGS2008

Enhanced sidescan-sonar imagery, north-central Long Island Sound

The U.S. Geological Survey, National Oceanic and Atmospheric Administration (NOAA), and Connecticut Department of Environmental Protection have been working cooperatively to map the sea-floor geology within Long Island Sound. Sidescan-sonar imagery collected during three NOAA hydrographic surveys (H11043, H11044, and H11045) was used to interpret the surficial-sediment distribution and sedimentary environments within the Sound. The original sidescan-sonar imagery generated by NOAA was used to evaluate hazards to navigation, which does not require consistent tonal matching throughout the survey. In order to fully utilize these data for geologic interpretation, artifacts within the imagery, primarily due to sidescan-system settings (for example, gain changes), processing techniques (for example, lack of across-track normalization) and environmental noise (for example, sea state), need to be minimized. Sidescan-sonar imagery from surveys H11043, H11044, and H11045 in north-central Long Island Sound was enhanced by matching the grayscale tones between adjacent sidescan-sonar lines to decrease the patchwork effect caused by numerous artifacts and to provide a more coherent sidescan-sonar image for use in geologic interpretation.

New York, Connecticut↗

USGS2005

Surficial geologic interpretation and sidescan sonar imagery of the sea floor in west-central Long Island Sound

The United States Geological Survey (USGS) is working cooperatively with the National Oceanic and Atmospheric Administration (NOAA) and Connecticut Department of Environmental Protection (CT-DEP) to conduct detailed studies of the surficial geology in Long Island Sound (LIS). The study goals are to interpret sedimentary environments within the Sound, to further understand processes controlling sediment distribution, and to provide a framework for future studies. Sidescan-sonar mosaics produced by USGS and NOAA show detailed acoustic images of the sea floor with 1- m resolution. These images, along with data obtained from sediment samples, seismic-reflection profiles, and seafloor video, are used to interpret the surficial geology. As part of this cooperative program, since 1995, 12 sidescan-sonar surveys of the LIS sea floor have been completed (Poppe and others, 1997; Twichell and others, 1997; Poppe and others, 1998a; Poppe and others, 1998b; Twichell and others, 1998; Poppe and others, 1999a; Poppe and others, 1999b; Poppe and others, 2001; Poppe and others, 2004; Zajac and others, 2003). The purpose of this report is to release digital versions of the imagery and interpretations from NOAA survey H11044 originally published in McMullen and others (2005). Survey H11044, which covers an area of 293 km 2 in west-central LIS , includes the area of the previously published Milford Survey (Twichell and others, 1998) and the westernmost part of the New Haven Harbor Survey (Poppe and others, 2001). These two surveys detailed surficial geology and mapped sediment distributions. In this study, we map the sediment distribution across a broader, previously unstudied area and the sedimentary environments.

Connecticut↗