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At least 631 records · Page 35Linked to original sources
USGS2026

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

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 (km 2 ) 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 km 2 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.

Quadrangle 3 of the Stellwagen Bank National Marin↗
USGS2017

Sediment data collected in 2014 and 2015 from around Breton and Gosier Islands, Breton National Wildlife Refuge, Louisiana

Breton Island, located at the southern end of the Chandeleur Islands, supports one of Louisiana’s largest historical brown pelican ( Pelecanus occidentalis ) nesting colonies. Although the brown pelican was delisted as an endangered species in 2009, nesting areas are threatened by continued land loss and are extremely vulnerable to storm impacts. The U.S. Fish and Wildlife Service proposed to restore Breton Island to pre-Hurricane Katrina conditions through rebuilding the shoreface, dune, and back-barrier marsh environments. Prior to restoration, scientists from the U.S. Geological Survey’s (USGS) St. Petersburg Coastal and Marine Science Center Geologic and Morphologic Evolution of Coastal Margins project collected high-resolution geophysical (topography, bathymetry, and sub-bottom profiles) and sedimentologic data from around Breton Island to characterize the geologic framework of the island platform, nearshore, and shelf environments. These data will be used to characterize the geologic framework around Breton Island, identify potential borrow areas for restoration efforts, quantify seafloor change, and provide information for sediment transport and morphologic change models to assess island response to restoration and natural processes. This report, along with the accompanying USGS data release, serves as an archive of sediment data from vibracores, push cores, and submerged grab samples collected from around Breton and Gosier Islands, Louisiana, during two surveys conducted in July 2014 and January 2015 (USGS Field Activity Numbers 2014–314–FA and 2014–336–FA, respectively). Sedimentologic and stratigraphic metrics (for example, sediment texture or unit thicknesses) derived from these data can be used to ground-truth the geophysical data and characterize potential sand resources or can be incorporated into sediment transport or morphologic change models. Data products, including sample location tables, descriptive core logs, core photographs and x-radiographs, results of sediment grain-size analyses, and geographic information system data files with accompanying formal Federal Geographic Data Committee metadata can be downloaded from the accompanying data release.

Louisiana↗
USGS2007

Submarine ground water discharge and fate along the coast of Kaloko-Honokohau National Historical Park, Hawaii Part I: Time-series measurements of currents, waves, salinity and temperature: November 2005 – July 2006

The impending development for the west Hawai‘i coastline adjacent to Kaloko-Honokōhau National Historical Park (KAHO) may potentially alter coastal hydrology and water quality in the marine waters of the park. Water resources are perhaps the most significant natural and cultural resource component in the park, and are critical to the health and well being of six federally listed species. KAHO contains ecosystems of brackish anchialine pools, two 11-acre fishponds, and 596 acres of coral reef habitats, all fed by groundwater originating upslope. The steep gradients on high islands, combined with typically porous substrates and high rainfall levels at upper elevations, make these settings especially vulnerable to shifts in submarine groundwater discharge (SGD) and its entrained nutrients and pollutants. Little is known about the magnitude, rate, frequency, and variability of SGD and its influence on contaminant loading to Hawaiian coastal environments. Recent studies show that groundwater flux through the park is vital to many ecosystem components including anchialine ponds and wetland biota. The function of these ecosystems may be vulnerable to changes in groundwater flow stemming from natural changes (climate and sea level) and land use (groundwater pumping and contamination). Oki and others (1999) showed that increased groundwater withdrawals for urban development since 1978 likely decreased groundwater flux to the coast by 50%. During this same time, the quality of groundwater has been vulnerable to increases in contaminant and nutrient/fertilizer additions associated with industrial, commercial and residential use upslope from KAHO (Oki and others, 1999). High-resolution measurements of waves, currents, water levels, temperature and salinity were collected in the marine portion of the park from November, 2005, through July, 2006, to establish baseline information on the magnitude, rate, frequency, and variability of SGD. These data are intended to help researchers and resource managers better understand the hydrodynamics of the oceanographic environment in the park’s coastal waters as it pertains to the pathway of SGD and associated nutrient and contaminant input to the park’s coral reef ecosystem. Measurements were made of the oceanographic environment (waves, tides, currents, salinity and temperature) using hydrodynamic techniques to characterize and quantify the distribution, input and throughput of freshwater and associated nutrient/contaminant within the near shore environment of KAHO through the emplacement of a series of bottom-mounted instruments deployed in water depths less than 15 m. This study was conducted in support of the National Park Service (NPS) by the U.S. Geological Survey (USGS) Coastal and Marine Geology Program’s Coral Reef Project. These measurements support the ongoing studies of the Coral Reef Project to better understand the transport mechanisms of sediment, larvae, nutrients, pollutants and other particles on Pacific coral reefs. Subsequent reports will address the spatial and temporal variability in groundwater input and the associated nutrient flux in the park’s waters.

Hawai'i↗
USGS2014

USGS Field Activities 12BHM01, 12BHM02, 12BHM03, 12BHM04, and 12BHM05 on the West Florida Shelf, in February, April, May, June, and August 2012

Atmospheric carbon dioxide (CO 2 ) is absorbed by the ocean’s surface where it combines with seawater to form a weak, naturally occurring acid called carbonic acid (H 2 CO 3 ). Increasing carbon dioxide in the atmosphere results in the absorption of more CO 2 by the ocean and, therefore, increases in the acidity of seawater. This process, known as ocean acidification, has the potential to elicit change in ecosystems and organisms by disrupting biological processes. For example, ocean acidification is a problem for marine organisms such as corals, foraminifera, and algae that precipitate calcium carbonate to form their skeletons and shells (Kleypas and others, 2006). The effects are related to corresponding changes in the carbonate saturation state (Ω), where Ω is the ratio of the ion concentration product (Ca 2+ x CO 3 2- ) to the stoichiometric aragonite solubility product (K*sp) (Langdon and Atkinson, 2005). Because pH and CO 3 2- are strongly interdependent through the inorganic carbon system, the decrease in pH will cause a proportionally greater decrease in CO 3 2- . Globally, ocean acidification is occurring faster than at any time in the last 300 million years (Broeker and others, 1979). Recent evidence indicates that individual oceans are responding at different rates, depending on physical and biological processes. For example in the Arctic Ocean, the rate of saturation state decrease was 2.1 percent per year between 1997 and 2010 (Robbins and others., 2013) in an area as large as Montana, largely because of increases in melt of ice, versus the average rate observed for the Pacific Ocean (0.36 percent per year) (Feely and others, 2012). Unfortunately, comparative data sets over multiyear time frames are often not available because time series baseline carbon information has not been collected in many oceans. Data are needed in subtropical latitudes where carbonate saturation states are already naturally low and fluctuate seasonally. These data will help construct a baseline for the assessment of future changes. As part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program project "R esponse of Florida Shelf Ecosystems to Climate Change " and in partnership with Kendra Daly, University of South Florida ( USF ), data on surface ocean carbonate chemistry were collected on five cruises along transects on the shallow inner west Florida shelf and northern Gulf of Mexico in 2012. Data from the 2011 cruises were also published (Robbins and others., 2013). The data collected allows the USGS, National Oceanic and Atmospheric Administration ( NOAA ), and USF scientists to map variations in ocean chemistry including carbonate saturation states along designated tracks. The USGS also partners with NOAA and the National Aeronautics and Space Administration ( NASA ) to model air-sea flux as part of a Gulf of Mexico Carbon Synthesis project led by NASA.

Florida↗
USGS2011

USGS St. Petersburg Coastal and Marine Science Center

Extreme storms, sea-level rise, and the health of marine communities are some of the major societal and environmental issues impacting our Nation's marine and coastal realm. The U.S. Geological Survey (USGS) in St. Petersburg, Fla., investigates processes related to these ecosystems and the societal implications of natural hazards and resource sustainability. As one of three centers nationwide conducting research within the USGS Coastal and Marine Geology Program, the center is integral towards developing an understanding of physical processes that will contribute to rational decisions regarding the use and stewardship of national coastal and marine environments.

Florida↗
USGS2004

Data from stratigraphic test holes drilled at the U.S. Marine Corps Air Station, Cherry Point, North Carolina, 1994-2001, and periodic water levels, 2000-2003

Nine stratigraphic test holes, from 158 to 305 feet deep, were drilled at the U.S. Marine Corps Air Station at Cherry Point, North Carolina, between 1994 and 2001 by the U.S. Geological Survey. These test holes and subsequent wells provide information about the lithology, stratigraphy, and geology at the Marine Corps Air Station. In addition, ground-water-level data were collected at the Air Station through 2003. The U.S. Geological Survey also conducted high-resolution marine and land seismic surveys during this investigation. The ground-water-level data and locations of the seismic survey lines are included in this report. The stratigraphic data combined with the seismic data provide a basis for the delineation of paleochannels beneath the Air Station as well as information for the management of water resources at the Air Station.

Open-File Report↗
USGS1985

CONMAP - USGS MARINE MAPPING PROGRAM.

The U. S. Geological Survey has commenced a marine mapping program, CONMAP (the Continental Margin Maps), which is supported by, and dependent on, a foundation of digital data-bases. The goal of the program's first phase is to prepare a series of maps that completely cover the Exclusive Economic Zone. The maps will be prepared using an Albers' Conic Equal-Area Projection at a scale of 1:1,000,000. An initial product of CONMAP will be a series of base map panels portraying the topographic and bathymetric relief, political boundaries and key geographic locations. Additional maps will be prepared which portray other data types and analytical themes.

Conference Paper↗
USGS2015

Seabed maps showing topography, ruggedness, backscatter intensity, sediment mobility, and the distribution of geologic substrates in Quadrangle 6 of the Stellwagen Bank National Marine Sanctuary Region offshore of Boston, Massachusetts

The U.S. Geological Survey (USGS), in cooperation with the National Oceanic and Atmospheric Administration's National Marine Sanctuary Program, has conducted seabed mapping and related research in the Stellwagen Bank National Marine Sanctuary (SBNMS) region since 1993. The area is approximately 3,700 square kilometers (km 2 ) and is subdivided into 18 quadrangles. Seven maps, at a scale of 1:25,000, of quadrangle 6 (211 km 2 ) depict seabed topography, backscatter, ruggedness, geology, substrate mobility, mud content, and areas dominated by fine-grained or coarse-grained sand. Interpretations of bathymetric and seabed backscatter imagery, photographs, video, and grain-size analyses were used to create the geology-based maps. In all, data from 420 stations were analyzed, including sediment samples from 325 locations. The seabed geology map shows the distribution of 10 substrate types ranging from boulder ridges to immobile, muddy sand to mobile, rippled sand. Mapped substrate types are defined on the basis of sediment grain-size composition, surface morphology, sediment layering, the mobility or immobility of substrate surfaces, and water depth range. This map series is intended to portray the major geological elements (substrates, topographic features, processes) of environments within quadrangle 6. Additionally, these maps will be the basis for the study of the ecological requirements of invertebrate and vertebrate species that utilize these substrates and guide seabed management in the region.

Massachusetts↗
USGS2013

Archive of U.S. Geological Survey selected single-beam bathymetry datasets, 1969-2000

New national programs, as well as natural and man-made disasters, have raised awareness about the need to find new and improved ways to share information about the coastal and marine environment with a wide-ranging public audience. The U.S. Geological Survey (USGS) Coastal and Marine Geology Program (CMGP) has begun a large-scale effort to incorporate the program's published, digital geophysical data into a single point of access known as the Coastal and Marine Geoscience Data System (CMGDS) (http://cmgds.marine.usgs.gov/). To aid in data discovery, work is also being done to import CMGP data into highly visible data and information resources, such as the National Oceanic and Atmospheric Administration's (NOAA) National Geophysical Data Center (NGDC) and two widely used Earth-science tools, GeoMapApp (GMA) (http://www.geomapapp.org) and Virtual Ocean (VO) (http://www.virtualocean.org/). This task of the CMGP Integrated Data Management System project will help support information exchange with partners, regional planning groups, and the public, as well as facilitate integrated spatial-data analysis. Sharing USGS-CMGP geophysical data via CMGDS, NGDC, GMA, and VO will aid data discovery and enable the data to support new purposes beyond those for which the data were originally intended. In order to make data available to NGDC, and from there into GMA and VO, the data must be reformatted into a standard exchange format and published. In 1977, a group of geophysical data managers from the public and private sectors developed the MGD77 format as the standard exchange format for geophysical data. In 2010, a tab-delimited version of the format was added as MGD77T (Hittelman and others, 1977). The MGD77T geophysical data format can include bathymetry, magnetics, gravity, and seismic navigation data. It is used for the transmission of data between marine institutions, data centers, and can be used by various software programs as an exchange format. A header (documentation) file and data file are created for each survey (Hittelman and others, 1977). More details about the MGD77T format are available at http://www.ngdc.noaa.gov/mgg/dat/geodas/docs/mgd77.pdf (74MB PDF). This archive describes the detailed steps used to convert single-beam bathymetry and navigation files into the MGD77T format (Hittelman and others, 1977) for submission to NGDC and formal Federal Geographic Data Committee (FGDC) (http://www.fgdc.gov/metadata) metadata as a publication of these single-beam bathymetry datasets.

Data Series↗
USGS2007

Surficial sediment character of the New York-New Jersey offshore continental shelf region: A GIS compilation

Broad continental shelf regions such as the New York Bight are the product of a complex geologic history and dynamic oceanographic processes, dominated by the Holocene marine transgression (>100 m sea-level rise) following the end of the last Pleistocene ice advance ~ 20,000 years ago. The area of the U.S. Exclusive Economic Zone (U.S. EEZ) territory, extending 200 nautical miles seaward from the coast, is larger than the continental U.S. and contains submerged landforms that provide a variety of natural functions and societal benefits, such as: critical habitats for fisheries, ship navigation and homeland security, and engineering activities (i.e. oil and gas platforms, pipeline and cable routes, potential wind-energy-generation sites). Some parts of the continental margins, particularly inner-continental shelf regions, also contain unconsolidated hard-mineral deposits such as sand and gravel that are regarded as potential aggregate resources to meet or augment needs not met by onshore deposits (Williams, 1992). The present distribution of surficial sediment off the northeastern United States is shaped from the deposits left by the last glaciation and reflects the cumulative effects of sediment erosion, transport, sorting, and deposition by storm and tidal processes during the Holocene rise in sea level. As a result, the sediments on the sea floor represent both an historical record of former conditions and a guide to possible future sedimentary environments. The U.S. Geological Survey (USGS) through the Coastal and Marine Geology Program, in cooperation with the University of Colorado and other partners, has compiled extant sediment character and textural data as well as other geologic information on the sea floor from all regions around the U.S. into the usSEABED data system (Reid and others, 2005; Buczkowski and others, 2006; Reid and others, 2006). The usSEABED system, which contains information on sediment grain size and lithology for more than 340,500 stations within the U.S. EEZ. has been developed and populated with data as part of the USGS Marine Aggregate Resources and Processes and the National Benthic Habitats projects in order to provide the base-line data needed to update the current maps of offshore surficial geologic character and sediment distribution. The maps are also used to characterize benthic sea floor environments important for marine ecosystems. U.S. Geological Survey, Data Series 118 (Reid and others, 2005), of the usSEABED data release series, represents the combined efforts of the USGS and several other government agencies to provide a unified resource for accessing and preserving records of U.S. east coast sea floor geologic information and sediment texture data. For this present report, we have chosen to focus on the New York-New Jersey region, an area that has been intensely studied by the USGS for many years to address many complex issues. This report illustrates the uses of the usSEABED database for GIS applications, while offering additional insight into the resources and data available from the USGS and its collaborative institutions. This report is based on data contained in U.S. Geological Survey Data Series 118 (Reid and others, 2005) and shows an assortment of example GIS products that are possible using usSEABED. All data are intended to be GIS-ready and should not require any additional cleanup, formatting, or renaming of fields in order to use the data in a Geographic Information System. This project employs the Environmental Systems Research Institute's (ESRI) ArcView™ software. Many of these maps were made as part of the ongoing USGS study to assess marine aggregate resources offshore New York and New Jersey, but these maps can serve many other purposes. The marine science community, educators, students and others are encouraged to use these data to generate GIS products for their own purposes. The objectives of the Marine Aggregate Resources and Processes project are to produce a series of new geologic maps and reports of the sea floor that will provide scientific insights into the character and geologic development of U.S. continental margins and to use these maps and information to assess the potential availability of offshore sand and gravel resources. The mapping and aggregate resource assessments are being conducted on a national scale using the usSEABED data base as described in Williams and others (2003). Potential uses for these data include: (1) defining the geological variability of the sea floor in relation to benthic habitat diversity; (2) improving our understanding of the processes that control the distribution and transport of bottom sediments and benthic habitats; (3) locating aggregate resources for beach nourishment and industrial applications; and (4) providing a detailed geospatial framework for future marine science research, monitoring, and management activities. The initial assessments are in progress for the New York Bight and Louisiana offshore areas.

New Jersey, New York↗
USGS2024

Editorial: From cold seeps to hydrothermal vents: Geology, chemistry, microbiology, and ecology in marine and coastal environments

This Research Topic compiles contemporary studies on cold seeps, hydrothermal vents, mud volcanoes, and related seafloor features that are associated with focused fluid emissions and the transfer of carbon, other chemical species, and sometimes heat from the geosphere to the ocean. Because these features sometimes tap fluids and gas originating kilometers below the seafloor, they provide an important window into deep processes that are otherwise inaccessible to scientists. At the shallow portion of their journey, migrating fluids nearing the seafloor contribute to a range of unique biological, physical, and chemical processes within the sediments themselves and at the sediment-water interface. Seafloor fluid emissions play a critical role in global biogeochemical cycles, ocean chemistry, and possibly even climate change. Seafloor leakage points often emit hydrocarbon gases (especially methane and CO 2 ) and are sometimes the loci for deposition of seafloor minerals that have economic value. A burgeoning area of research focuses on natural products generated at these features, seeking compounds with potential pharmaceutical or other applications. Multidisciplinary studies have become routine for characterization of seafloor fluid emission sites, attesting to the inseparability of geologic, physical, chemical, and biological processes in these settings. It is increasingly common for researchers to combine in a single research cruise: subbottom imaging and seafloor mapping; porewater and water column geochemistry and gas sampling; sediment retrieval for lithologic, biostratigraphic, and solid phase analyses; and studies of benthic and subseafloor communities at the microbial to macrofaunal scales. This multidisciplinary approach has the advantage of ensuring the spatial and temporal coincidence of surveys and samples, an important factor at highly dynamic seafloor fluid emission sites. In addition, researchers often use remotely operated vehicles (ROVs), autonomous underwater vehicles (AUVs), or human-occupied vehicles (HOVs) to record video of the seafloor, compile photomosaics, collect targeted samples, and survey with high-resolution geophysical near-seafloor systems, providing a degree of detail about seafloor fluid emission sites that is unprecedented compared to most areas of the deep ocean. While rarer, long-term cabled observatories or shorter-term deployments of portable observatories are also used at some loci for seafloor fluid flux and are particularly helpful for capturing temporal variations at these dynamic features. Here we summarize the Research Topic’s contribution to multidisciplinary seafloor emission studies in the categories of cold seeps, mud volcanoes, and hydrothermal vents. Figure 1 shows the geographic distribution of the studies in this Research Topic and key features referred to in this Introduction.

Frontiers in Earth Science↗
USGS2000

High-resolution marine seismic reflection data from the San Francisco Bay area

Between 1993 and 1997, the U.S. Geological Survey acquired high-resolution, marine seismic-reflection profile data across submerged portions of known and inferred upper crustal fault zones throughout the greater San Francisco Bay area. Surveys were conducted oversouth San Francisco Bay in the vicinity of the San Bruno shoal (roughly between the San Francisco and Oakland airports), over the offshore extension of the San Andreas fault system west of the Golden Gate, over the Hayward fault to Rodgers Creek fault step-over in San Pablo Bay, and over the Kirby Hills fault where it crosses the western Sacramento Delta. Reconnaissance profiles were acquired elsewhere throughout the San Francisco and San Pablo Bays. These data were acquired by the U.S. Geological Survey, Western Coastal and Marine Geology Team, under the auspices of the Central California/San Francisco Bay Earthquake Hazards Project. Analysis and interpretation of some of these profiles has been published by Marlow and others (1996, 1999). Further analysis and interpretation of these data are available in a USGS. Professional Paper Crustal Structure of the Coastal and Marine San Francisco Bay Region, T. Parsons, editor, http://geopubs.wr.usgs.gov/prof-paper/pp1658/ [link added 2012 mfd].

California↗
USGS2007

Proceedings of the Fourth Glacier Bay Science Symposium

Foreword Glacier Bay was established as a National Monument in 1925, in part to protect its unique character and natural beauty, but also to create a natural laboratory to examine evolution of the glacial landscape. Today, Glacier Bay National Park and Preserve is still a place of profound natural beauty and dynamic landscapes. It also remains a focal point for scientific research and includes continuing observations begun decades ago of glacial processes and terrestrial ecosystems. In recent years, research has focused on glacial-marine interactions and ecosystem processes that occur below the surface of the bay. In October 2004, Glacier Bay National Park convened the fourth in a series of science symposiums to provide an opportunity for researchers, managers, interpreters, educators, students and the general public to share knowledge about Glacier Bay. The Fourth Glacier Bay Science Symposium was held in Juneau, Alaska, rather than at the Park, reflecting a desire to maximize attendance and communication among a growing and diverse number of stakeholders interested in science in the park. More than 400 people attended the symposium. Participants provided 46 oral presentations and 41 posters covering a wide array of disciplines including geology, glaciology, oceanography, wildlife and fisheries biology, terrestrial and marine ecology, socio-cultural research and management issues. A panel discussion focused on the importance of connectivity in Glacier Bay research, and keynote speakers (Gary Davis and Terry Chapin) spoke of long-term monitoring and ecological processes. These proceedings include 56 papers from the symposium. A summary of the Glacier Bay Science Plan-itself a subject of a meeting during the symposium and the result of ongoing discussions between scientists and resource managers-also is provided. We hope these proceedings illustrate the diversity of completed and ongoing scientific studies, conducted within the Park. To this end, we invited all presenters to submit brief technical summaries of their work, to capture the gist of their study and its main findings without an overload of details and methodology. We also asked authors to include a few words on the management implications of their work to help bridge the gap between scientists and managers in understanding how specific research questions may translate to management practice. Papers in this volume are laid out by subject matter, from terrestrial and freshwater subjects to glacial-marine geology, to the ecology of marine animals and ending with risk assessment, human impacts and science-management considerations. In summary, we hope the proceedings will serve as a useful reference to completed and ongoing studies in Glacier Bay National Park, and thereby provide park enthusiasts, scientists, and managers with a road map of scientific progress.

Scientific Investigations Report↗
USGS2006

Textural analysis of marine sediments at the USGS Woods Hole Science Center; methodology and data on DVD

Marine sediments off the eastern United States vary markedly in texture (i.e., the size, shape, composition, and arrangement of their grains) due to a complex geologic history. For descriptive purposes, however, it is typically most useful to classify these sediments according to their grain-size distributions. In 1962, the U.S. Geological Survey began a program to study the marine geology of the continental margin off the Atlantic coast of the United States. As part of this program and numerous subsequent projects, thousands of sediment grab samples and cores were collected and analyzed for grain size at the Woods Hole Science Center. USGS Open-File Report 2005-1001 (Poppe et al., 2005), available on DVD and online, describes the field methods used to collect marine sediment samples as well as the laboratory methods used to determine and characterize grain-size distributions, and presents these data in several formats that can be readily employed by interested parties. The report is divided into three sections. The first section discusses procedures and contains pictures of the equipment, analytical flow diagrams, video clips with voice commentary, classification schemes, useful forms and compiled and uncompiled versions of the data-acquisition and data-processing software with documentation. The second section contains the grain-size data for more than 23,000 analyses in two “flat-file” formats, a data dictionary, and color-coded browse maps. The third section provides a GIS data catalog of the available point, interpretive, and baseline data layers, with FGDC-compliant metadata to help users visualize the textural information in a geographic context.

Conference Paper↗
USGS2007

Benthic habitats and offshore geological resources of Kaloko-Honokohau National Historical Park, Hawai‘i

Kaloko-Honokōhau National Historical Park (KAHO) is one of three National Park lands located along the western coast of the Island of Hawai‘i and the only one to include submerged lands and marine resources within its official boundaries. The park was established in 1978 and is 1,160 acres in size, including 596 acres of marine area. The submerged lands are currently managed by the State of Hawaii, Department of Land and Natural Resources, Division of Aquatic Resources (DLNR-DAR). Marine resources located within KAHO include coral reef and habitat for many marine animals, including the green sea turtle and a variety of fish and invertebrates. In addition, many archeological, cultural, and recreational resources are located within the marine realm of the park. Potential threats and stressors to the modern marine environment include ground-water and surface-water contamination, invasive plants and algae, fishing pressure and use of monofilament gill nets (which can ensnare marine life or become tangled on reefs and be left behind as fishing debris), and visitor use impacts, such as scuba diving and snorkeling. Illegal dumping, oil releases, boat groundings, and other physical damage to reef resources are potential threats from users of the nearby harbor. Special issues of concern for the park include establishing baseline conditions of the offshore resources before the development of adjacent coastal lands. Until this study, only a general knowledge of the distribution of benthic habitats and the characteristics of the offshore region of Kaloko-Honokōhau National Historical Park was available. In 2003, a collaborative project between the U.S. Geological Survey (USGS) Coastal and Marine Geology Program and the National Park Service (NPS) was initiated to develop detailed benthic-habitat classification maps for the marine lands within and adjacent to the park. The intent of this project is to provide baseline maps and a Geographic Information System (GIS) database and description of the biological and geological resources of these marine lands in order to facilitate the management, interpretation, and understanding of park resources. A benthic-habitat classification map was created for the park using existing color aerial photography, Scanning Hydrographic Operational Airborne Lidar Survey (SHOALS) bathymetric data, georeferenced underwater video, and still photography. Individual habitat polygons were classified using five basic attributes: (1) major structure or substrate, (2) dominant structure, (3) major biologic cover on the substrate, (4) percentage of major biological cover, and (5) geographic zone. Additional information regarding geology, morphology, and coral species were also noted. Marine resources located within KAHO include coral reef and habitat for many marine animals, including the green sea turtle and a variety of fish and invertebrates. In addition, many archeological, cultural, and recreational resources are located within the marine realm of the park. Potential threats and stressors to the modern marine environment include ground-water and surface-water contamination, invasive plants and algae, fishing pressure and use of monofilament gill nets (which can ensnare marine life or become tangled on reefs and be left behind as fishing debris), and visitor use impacts, such as scuba diving and snorkeling. Illegal dumping, oil releases, boat groundings, and other physical damage to reef resources are potential threats from users of the nearby harbor. Special issues of concern for the park include establishing baseline conditions of the offshore resources before the development of adjacent coastal lands. Until this study, only a general knowledge of the distribution of benthic habitats and the characteristics of the offshore region of Kaloko-Honokōhau National Historical Park was available. In 2003, a collaborative project between the U.S. Geological Survey (USGS) Coastal and Marine Geology Program and the National Park Service (NPS) was initiated to develop detailed benthic-habitat classification maps for the marine lands within and adjacent to the park. The intent of this project is to provide baseline maps and a Geographic Information System (GIS) database and description of the biological and geological resources of these marine lands in order to facilitate the management, interpretation, and understanding of park resources. A benthic-habitat classification map was created for the park using existing color aerial photography, Scanning Hydrographic Operational Airborne Lidar Survey (SHOALS) bathymetric data, georeferenced underwater video, and still photography. Individual habitat polygons were classified using five basic attributes: (1) major structure or substrate, (2) dominant structure, (3) major biologic cover on the substrate, (4) percentage of major biological cover, and (5) geographic zone. Additional information regarding geology, morphology, and coral species were also noted.

Hawai'i↗
USGS2013

Scientific results of the Second Gas Hydrate Drilling Expedition in the Ulleung Basin (UBGH2)

As a part of Korean National Gas Hydrate Program, the Second Ulleung Basin Gas Hydrate Drilling Expedition (UBGH2) was conducted from 9 July to 30 September, 2010 in the Ulleung Basin, East Sea, offshore Korea using the D/V Fugro Synergy. The UBGH2 was performed to understand the distribution of gas hydrates as required for a resource assessment and to find potential candidate sites suitable for a future offshore production test, especially targeting gas hydrate-bearing sand bodies in the basin. The UBGH2 sites were distributed across most of the basin and were selected to target mainly sand-rich turbidite deposits. The 84-day long expedition consisted of two phases. The first phase included logging-while-drilling/measurements-while-drilling (LWD/MWD) operations at 13 sites. During the second phase, sediment cores were collected from 18 holes at 10 of the 13 LWD/MWD sites. Wireline logging (WL) and vertical seismic profile (VSP) data were also acquired after coring operations at two of these 10 sites. In addition, seafloor visual observation, methane sensing, as well as push-coring and sampling using a Remotely Operated Vehicle (ROV) were conducted during both phases of the expedition. Recovered gas hydrates occurred either as pore-filling medium associated with discrete turbidite sand layers, or as fracture-filling veins and nodules in muddy sediments. Gas analyses indicated that the methane within the sampled gas hydrates is primarily of biogenic origin. This paper provides a summary of the operational and scientific results of the UBGH2 expedition as described in 24 papers that make up this special issue of the Journal of Marine and Petroleum Geology.

East Sea Of Korea;Ulleung Basin↗
USGS2001

Geologic Map of the Hellas Region of Mars

INTRODUCTION This geologic map of the Hellas region focuses on the stratigraphic, structural, and erosional histories associated with the largest well-preserved impact basin on Mars. Along with the uplifted rim and huge, partly infilled inner basin (Hellas Planitia) of the Hellas basin impact structure, the map region includes areas of ancient highland terrain, broad volcanic edifices and deposits, and extensive channels. Geologic activity recorded in the region spans all major epochs of martian chronology, from the early formation of the impact basin to ongoing resurfacing caused by eolian activity. The Hellas region, whose name refers to the classical term for Greece, has been known from telescopic observations as a prominent bright feature on the surface of Mars for more than a century (see Blunck, 1982). More recently, spacecraft imaging has greatly improved our visual perception of Mars and made possible its geologic interpretation. Here, our mapping at 1:5,000,000 scale is based on images obtained by the Viking Orbiters, which produced higher quality images than their predecessor, Mariner 9. Previous geologic maps of the region include those of the 1:5,000,000-scale global series based on Mariner 9 images (Potter, 1976; Peterson, 1977; King, 1978); the 1:15,000,000-scale global series based on Viking images (Greeley and Guest, 1987; Tanaka and Scott, 1987); and detailed 1:500,000-scale maps of Tyrrhena Patera (Gregg and others, 1998), Dao, Harmakhis, and Reull Valles (Price, 1998; Mest and Crown, in press), Hadriaca Patera (D.A. Crown and R. Greeley, map in preparation), and western Hellas Planitia (J.M. Moore and D.E. Wilhelms, map in preparation). We incorporated some of the previous work, but our map differs markedly in the identification and organization of map units. For example, we divide the Hellas assemblage of Greeley and Guest (1987) into the Hellas Planitia and Hellas rim assemblages and change the way units within these groupings are identified and mapped (table 1). The new classification scheme includes broad, geographically related categories and local, geologically and geomorphically related subgroups. Because of our mapping at larger scale, many of our map units were incorporated within larger units of the global-scale mapping (see table 1). Available Viking images of the Hellas region vary greatly in several aspects, which has complicated the task of producing a consistent photogeologic map. Best available image resolution ranges from about 30 to 300 m/pixel from place to place. Many images contain haze caused by dust clouds, and contrast and shading vary among images because of dramatic seasonal changes in surface albedo, opposing sun azimuths, and solar inclination. Enhancement of selected images on a computer-display system has greatly improved our ability to observe key geologic relations in several areas. Determination of the geologic history of the region includes reconstruction of the origin and sequence of formation, deformation, and modification of geologic units constituting (1) the impact-basin rim and surrounding highlands, (2) volcanic and channel assemblages on the northeast and south sides of the basin, (3) interior basin deposits, and (4) slope and surficial materials throughout the map area. Various surface modifications are attributed to volcanic, fluvial, eolian, mass-wasting, and possibly glacial and periglacial processes. Structures include basin faults (mostly inferred), wrinkle ridges occurring mainly in volcanic terrains and interior plains, volcanic collapse craters, and impact craters. Our interpretations in some cases rely on previous work, but in many significant cases we have offered new interpretations that we believe are more consistent with the observations documented by our mapping. Our primary intent for this mapping has been to elucidate the history of emplacement and modification of Hellas Planitia materials, which form the basis for analysis of their r

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