Sonar mapping of the sea floor provides CMG researchers with very useful data. Some sonar systems map the topography of the sea floor by recording large swaths of depth measurements. Others collect information useful in determining the geologic makeup of the sea floor and the sub-surface structure.
California Seafloor Mapping Program The California Seafloor Mapping Program (CSMP) is a cooperative program to create a comprehensive coastal/marine geologic and habitat base map series for all of California’s State waters. The Ocean Protection Council authorized funds to establish the CSMP in 2007 (OPC, 2007) and assembled a team of experts from state and federal agencies, academia, and private industry to develop the best approach to mapping and classifying estuarine and marine geologic habitats, while at the same time updating all nautical charts. Initiated in 2008, the CSMP is collecting bathymetry (underwater topography) and backscatter data (providing insight into the geologic makeup of the seafloor) that will be turned into habitat and geologic base maps for all of California’s state waters (mean high water line out to three nautical miles). Although the CSMP was originally developed to support the design and monitoring of marine reserves through the Marine Life Protection Act (CDFG, 2007), accurate statewide mapping of the seafloor will: - improve climate change and ocean circulation models; - help evaluate the potential for ocean energy; - improve our understanding of ecosystem dynamics; - identify submerged faults and improve our understanding of tsunami potential - enable more effective regulation of offshore development; - improve maritime safety; and - improve our understanding of sediment transport and sand delivery. Posted: 2010-02-23
Santa Barbara-Ventura Coastal Processes Study - USGS WCMG Santa Barbara/Ventura Coastal Processes Study of the USGS Western Coastal and Marine Geology Team. Whereas coastal urban development and infrastructure are largely fixed with respect to location, shoreline and bluff positions can change substantially over time in response to natural processes. These natural coastal changes can damage or undermine urban structures, resulting in substantial property loss for federal, state, local and individual land owners. Urban development can also indirectly influence coastal change by interrupting natural supplies or transport of sediment in littoral cells. Thus, it is important to evaluate the rates, patterns and causes of coastal change to better manage sediment resources and predict change hazards in coastal urban settings. The Santa Barbara and Ventura County coast represents a littoral cell along the California coast extending from (at least) Point Conception to the Mugu submarine canyon. The beaches along this littoral cell are an important economic resource to the region, and there is evidence that shoreline and bluff erosion are impacting these beaches. Coastal change in the Santa Barbara/Ventura region is complicated, however, by the irregular coastline (there are numerous rocky headlands, river deltas and offshore reefs), variability in wave forcing, structures such as harbors, groins, piers, dams and landscape urbanization, variability in tectonic uplift, and limited information on littoral sediment sources. In response to the potential for coastal change, BEACON (Beach Erosion Authority for Clean Oceans and Nourishment) and the City of Carpinteria have provided a combined $700K in funding for USGS WCMG to evaluate the coastal change patterns and processes along the Santa Barbara/Ventura County coast until the end of 2008. Posted: 2009-11-24
General Information Product 87: Sea Floor off San Diego, California Ocean-floor image generated from multibeam-bathymetry data acquired by the U.S. Geological Survey (USGS); Woods Hole Oceanographic Institution; Scripps Institution of Oceanography; California State University, Monterey Bay; and Fugro Pelagos. To learn more, visit http://pubs.usgs.gov/sim/2007/2959/. Posted: 2009-11-24
General Information Product 57: South San Francisco Bay, California The U.S. Geological Survey, in cooperation with the California Coastal Conservancy and the National Oceanic and Atmospheric Administration, mapped the floor of south San Francisco Bay and adjoining land using single-beam sonar and airborne lidar (light detection and ranging). To learn more, visit http://pubs.usgs.gov/sim/2007/2987/. Posted: 2009-11-24
Digital Data Series 55: Sea-Floor Images and Data from Multibeam Surveys in San Francisco Bay, Southern California, Hawaii, the Gulf of Mexico, and Lake Tahoe, California-Nevada Accurate base maps are a prerequisite for any geological study, regardless of the objectives. Land-based studies commonly utilize aerial photographs, USGS 7.5-minute quadrangle maps, and satellite images as base maps. Until now, studies that involve the ocean floor have been at a disadvantage due to an almost complete lack of accurate marine base maps. Many base maps of the sea floor have been constructed over the past century but with a wide range in navigational and depth accuracies. Only in the past few years has marine surveying technology advanced far enough to produce navigational accuracy of 1 meter and depth resolutions of 50 centimeters. The Pacific Seafloor Mapping Project, U.S. Geological Survey, Western Coastal and Marine Geology Program, Menlo Park, California, U.S.A. in cooperation with the Ocean Mapping Group, University of New Brunswick, Canada is using this new technology to systematically map the ocean floor and lakes. This type of marine surveying, called Multibeam surveying, collects high-resolution bathymetry and backscatter data that can be used for a variety of basemaps, GIS coverages, and scientific visualization methods. This is an interactive CD-ROM that contains images, movies, and data of all the surveys the Pacific Seafloor Mapping Project has completed up to January 1999. Images and movies on this CD-ROM, such as shaded relief of the bathymetry, backscatter, oblique views, 3-D views, and Quicktime movies (San Francisco, Los Angeles, and Lake Tahoe) help the viewer to visualize the multibeam data. This CD-ROM also contains ARC/INFO export (.e00) files and full resolution TIFF images of all the survey sites that can be downloaded and used in many GIS software. Posted: 2009-11-24
Open-File Report 2005-1153: Multibeam Bathymetry and Backscatter Data: Northeastern Channel Islands Region, Southern California The U.S. Geological Survey (USGS) in cooperation with the Minerals Management Service (MMS) conducted multibeam mapping in the eastern Santa Barbara Channel and northeastern Channel Islands region from August 8 to15, 2004 aboard the R/V Maurice Ewing. The survey was directed and funded by the Minerals Management Service, which is interested in maps of hardbottom habitats, particularly natural outcrops, that support reef communities in areas affected by oil and gas activity. The maps are also useful to biologists studying fish that use the platforms and the sea floor beneath them as habitat. The survey collected bathymetry and corrected, co-registered acoustic backscatter using a Kongsberg Simrad EM1002 multibeam echosounder that was mounted on the hull of the R/V Maurice Ewing. Three main regions were mapped during the survey including: (1) the Eastern Santa Barbara Channel adjacent to an area previously mapped with multibeam-sonar by the Monterey Bay Aquarium Research Institute (see the MBARI Santa Barbara Basin Multibeam Survey web page at http://www.mbari.org/data/mapping/SBBasin/), (2) the Footprint area south of Anacapa Island, which has been studied extensively by rockfish biologists and is considered a good site for a marine protected area, and (3) part of the submarine canyons along the continental slope south of Port Hueneme. These data will be used to support a number of new and ongoing projects including, habitat mapping, shelf and slope processes, and offshore hazards and resouces. For more information on the mapping mission see "Mapping Benthic Habitat Around Oil Platforms in the Santa Barbara Channel, California" at http://soundwaves.usgs.gov/2004/11/fieldwork3.html This Open-File Report publishes the multibeam bathymetry and acoustic backscatter data in a number of different formats, with Federal Geographic Data Committee (FGDC) metadata, along with maps and oblique views of particular areas of interest. Posted: 2009-11-24
Scientific Investigations Map 2907: Sidescan Sonar Imagery of the Escanaba Trough, Southern Gorda Ridge, Offshore Northern California This map features sidescan imagery of the northern Escanaba (NESCA) site at the Escanaba Trough, southern Gorda Ridge, offshore northern California. The Escanaba Trough, a largely sediment-covered seafloor spreading center, contains at least six large massive sulfide deposits. It is a slow spreading center (2.5 cm/yr) with axial depths locally exceeding 3,300 m. Discrete igneous centers occur at 5- to 10-km intervals along this slow-spreading ridge. Basaltic magma intrudes the sediment fill of the axial valley, creating uplifted sediment hills, and, in some areas, erupts onto the sea floor. Posted: 2009-09-30
Equipment Used in Marine Geology Research Description and links to information on nine types of marine geology research equipment used by the USGS Western Region Coastal & Marine Geology Team Posted: 2009-07-02
WCMG Marine Facility Home Page Links to software downloads and documentation for YoNav and MudSeis systems used on Western Region Coastal and Marine Geology Team cruises. Posted: 2009-07-02
USGS Northern Gulf of Mexico (NGOM) The goal of the USGS Northern Gulf of Mexico project is to understand the evolution of coastal ecosystems on the Northern Gulf Coast, the impact of human activities on these ecosystems, and the vulnerability of ecosystems and human communities to more frequent and more intense hurricanes in the future. Posted: 2009-05-28
National Seafloor Mapping and Characterization Images of the sea floor off the coasts of California, Hawaii, Florida, Mississippi, Alabama, Texas, Louisiana, and Washington; images of lake floor of Lake Michigan, Crater Lake, Lake Tahoe. Backscatter and swath bathymetry, regular and in 3-D view. Posted: 2009-05-11
Open-File Report 2009-1029: Coastal processes study of Santa Barbara and Ventura Counties, California By Patrick L. Barnard, David L. Revell, Dan Hoover, Jon Warrick, John Brocatus, Amy E. Draut, Pete Dartnell, Edwin Elias, Neomi Mustain, Pat E. Hart, and Holly F. Ryan. The Santa Barbara littoral cell (SBLC) is a complex coastal system with significant management challenges. The coastline ranges broadly in exposure to wave energy, fluvial inputs, hard structures, and urbanization. Geologic influence (structural control) on coastline orientation exerts an important control on local beach behavior, with anthropogenic alterations and the episodic nature of sediment supply and transport also playing important roles. Posted: 2009-03-27
Digital Data Series 72: 2000 Multibeam sonar survey of Crater Lake, Oregon - Data, GIS, images, and movies In the summer of 2000, the bottom of Crater Lake, Oregon was mapped. The effort was a cooperative effort between the U.S. Geological Survey's Pacific Seafloor Mapping Project, the National Park Service, and the Center for Coastal and Ocean Mapping at the University of New Hampshire. The team used a state-of-the-art multibeam sonar system to collect high-resolution bathymetry and calibrated, co-registered acoustic backscatter to support both biological and geological research in the area (aquatic biology, geochemistry, volcanic processes, etc). This survey collected over 16 million soundings and the resulting data portrays the bottom of Crater Lake at a spatial resolution of 2 meters. This CD-ROM is published for the scientific community, the general public, and as a teaching tool. The CD-ROM contains the raw multibeam bathymetry and backscatter data as well as an ArcExplorer 2.0 project for the scientific community to use in research. Computer-generated images and a fly-by movie allow any user to visualize the lake floor. Photographs and a QuickTime® movie of the helicopter operations shows how the multibeam survey took place and a list of Crater Lake publications and related websites can be used for further Crater Lake research and general interest. Posted: 2009-03-10
Scientific Investigations Report 2007-5101: The Coral Reef of South Moloka‘i, Hawai‘i—Portrait of a Sediment-Threatened Fringing Reef In this landmark volume, U.S. Geological Survey researchers and their colleagues have developed and applied a remarkably integrated approach to the reefs of Moloka‘i, combining geology, oceanography, and biology to provide an in-depth understanding of the processes that have made these reefs grow and that now limit them. They have joined old fashioned natural history of marine animals and plants with study of the geological evolution of the island, hydrology, meteorology, and land-use history, to an arsenal of new methods of remote sensing, including aerial photography, laser ranging, infrared thermal mapping, seismic reflection, in-situ instrumentation to measure chemical parameters of water quality, and direct measurements of the physical driving forces affecting them—such as wave energy, currents, sedimentation, and sediment transport. They provide a level of documentation and insight that has never been available for any reef before. Posted: 2008-11-19
USGS OFR 2008-1174: Enhanced Sidescan-Sonar Imagery, North-Central Long Island Sound, Title Page Sidescan-sonar imagery from NOAA surveys H11043, H11044, and H11045 in north-central Long Island Sound were enhanced to remove tonal artifacts by matching backscatter tones in adjacent sonar lines. The enhanced imagery minimizes abrupt backscatter changes and striping, and more clearly delineates boundaries of backscatter tones and patterns." Posted: 2008-11-17
Open-File Report 98-139: Multibeam Data and Socio-Economic Issues in West-Central San Francisco Bay Recent investigations by the USGS in the San Francisco Bay estuary help address both socio-economic and scientific issues: - How much rock must be trimmed from pinnacles on the bayfloor to provide safe navigation by deep-draft vessels? - What would be the environmental and societal consequences of a large oil spill? - What are the consequences of long-term dredging operations? - What types of bayfloor are important habitats for commercial and recreational fisheries? - What types of sediment cover the bayfloor? - What are the sediment distribution, volume, and rates of transport? Posted: 2008-10-10
WCMG Coastal Processes Studies California's beaches and nearshore regions are valuable economic and recreational resources but also provide habitats for numerous sensitive species. During winter storms, the coast represents a potentially dangerous interface between ocean and land, nature and humans. Storms produce high waves, strong currents, and elevated sea level that can rapidly erode beaches and inundate low-lying coastal regions, damaging and/or destroying public and private infrastructure as well as stressing coastal ecosystems. Over longer-time scales (e.g. decadal), persistent erosion exacerbated by the pressures of coastal development, reduction in sediment availability and climate change, can result in severely depleted beaches. The USGS performs research along the California coast to understand the physical processes that control coastal change on time scales from individual storms to decades to support the efforts of local, state and government agencies to make informed coastal management decisions to most effectively preserve and protect this valuable resource. Posted: 2008-09-23
USGS WCMG News, Scientists Map Unexplored Arctic Sea Floor News and Information about the USGS research aboard the US Coast Guard Cutter Healy, mapping the sea floor - the extended continental shelf - in the Artic Ocean this month. This research is being done to define the limits of the extended continental shelf, over which coastal nations can claim sovereign rights under the United Nations Convension on the Law of the Sea. Posted: 2008-09-23
Coastal Processes: San Francisco Bight Coastal Processes Study - USGS WCMG San Francisco Bight Coastal Processes Study of the USGS Western Coastal and Marine Geology Team. The USGS is conducting a study that documents and analyzes the processes that control the sand transport and sedimentation patterns of Ocean Beach, a National Park site within the Golden Gate National Recreation Area. This area encompasses a complicated coastal setting that is impacted by the tidal influence of San Francisco Bay, as well as the southwest and northwest Pacific swell. High-energy conditions at this site have restricted comprehensive field surveys in the past, but recent innovations in field techniques now make it possible to perform detailed analysis of the physical processes operating on high energy coastlines, such as Ocean Beach. Posted: 2008-08-12
Open-File Report 2008-1246: High-Resolution Chirp and Mini-Sparker Seismic-Reflection Data From the Southern California Continental Shelf—Gaviota to Mugu Canyon The U.S. Geological Survey (USGS) collected high-resolution shallow seismic-reflection data in September, 2007, and June-July, 2008, from the continental shelf offshore of southern California between Gaviota and Mugu Canyon, in support of the California's State Waters Mapping Program. Data were acquired using SIG 2mille mini-sparker and Edgetech chirp 512 instruments aboard the R/V Zephyr (Sept. 2007) and R/V Parke Snavely (June-July 2008). The survey area spanned approximately 120 km of coastline, and included shore-perpendicular transects spaced 1.0-1.5 km apart that extended offshore to at least the 3-mile limit of State waters, in water depths ranging from 10 m near shore to 300 m near the offshore extent of Mugu and Hueneme submarine canyons. Subbottom acoustic penetration spanned tens to several hundred meters, variable by location. This report includes maps of the surveyed transects, linked to Google Earth™ software, as well as digital data files showing images of each transect in SEG-Y, JPEG, and TIFF formats. The images of sediment deposits, tectonic structure, and natural-gas seeps collected during this study provide geologic information that is essential to coastal zone and resource management at Federal, State and local levels, as well as to future research on the sedimentary, tectonic, and climatic record of southern California. Posted: 2008-07-29
Scientific Investigations Map 3007: Views of the Sea Floor in Northern Monterey Bay, California A sonar survey that produced unprecedented high-resolution images of the sea floor in northern Monterey Bay was conducted in 2005 and 2006. The survey, performed over 14 days by the U.S. Geological Survey (USGS), consisted of 172 tracklines and over 300 million soundings and covered an area of 12.2 km2 (4.7 mi2). The goals of this survey were to collect high-resolution bathymetry (depth to the sea floor) and acoustic backscatter data (amount of sound energy bounced back from the sea floor, which provides information on sea-floor hardness and texture) from the inner continental shelf. These data will provide a baseline for future change analyses, geologic mapping, sediment- and contaminant-transport studies, benthic-habitat delineation, and numerical modeling efforts. The survey shows that the inner shelf in this area is extremely varied in nature, encompassing flat sandy areas, faults, boulder fields, and complex bedrock ridges that support rich marine ecosystems. Furthermore, many of these complex bedrock ridges form the “reefs” that result in a number of California”s classic surf breaks. Posted: 2008-06-09
Data Series 320: Sea-Floor Mapping and Benthic Habitat GIS for the Elwha River Delta Nearshore, Washington This is a description of selected data layers for the Sea-Floor Mapping and Benthic Habitat GIS for Puget Sound, Washington. From March 1531, 2005, more than 252 km (19.5 km2) of seafloor offshore of the Elwha River Delta in the central Strait of Juan de Fuca was mapped by the USGS Coastal and Marine Geology Program. The purpose of this nearshore mapping was to (1) obtain high resolution bathymetry and acoustic reflectance properties of the seabed, (2) examine and record geologic characteristics of the seafloor, and (3) construct maps of sea-floor geomorphology and habitat. Substrate distribution was characterized with video-supervised statistical classification of the sonar data. Substrate of the survey was dominated by mixed sand-gravel and sand. Numerous boulder reefs were observed west of the river mouth within Freshwater Bay, whereas the sea-floor immediately adjacent to the river mouth was dominated by sand. Posted: 2008-05-07
GIS Library, Multibeam Data, Massachusetts Bay, SBNM Sanctuary, USGS Data Series 99; Version 1.0; Start Page This Geographic Information Systems (GIS) library contains images and grids of bathymetry, shaded relief bathymetry, and backscatter intensity data from surveys of the Stellwagen Bank National Marine Sanctuary and western Massachusetts Bay, offshore of Boston, Massachusetts. The data are in an Environmental Systems Research Institute (www.esri.com) (ESRI) ArcMap 9.1 Geographic Information System project. The shapefiles, images, and grids may also be downloaded individually. Descriptions and interpretations of the data are available in a series of published maps. Posted: 2008-03-06
Scientific Investigations Report 2008-5009: Evaluation of a Single-Beam Sonar System to Map Seagrass at Two Sites in Northern Puget Sound, Washington Seagrass at two sites in northern Puget Sound, Possession Point and nearby Browns Bay, was mapped using both a single-beam sonar and underwater video camera. The acoustic and underwater video data were compared to evaluate the accuracy of acoustic estimates of seagrass cover. The accuracy of the acoustic method was calculated for three classifications of seagrass observed in underwater video: bare (no seagrass), patchy seagrass, and continuous seagrass. Acoustic and underwater video methods agreed in 92 percent and 74 percent of observations made in bare and continuous areas, respectively. However, in patchy seagrass, the agreement between acoustic and underwater video was poor (43 percent). The poor agreement between the two methods in areas with patchy seagrass is likely because the two instruments were not precisely colocated. The distribution of seagrass at the two sites differed both in overall percent vegetated and in the distribution of percent cover versus depth. On the basis of acoustic data, seagrass inhabited 0.29 km2 (19 percent of total area) at Possession Point and 0.043 km2 (5 percent of total area) at the Browns Bay study site. The depth distribution at the two sites was markedly different. Whereas the majority of seagrass at Possession Point occurred between -0.5 and -1.5 m MLLW, most seagrass at Browns Bay occurred at a greater depth, between -2.25 and -3.5 m MLLW. Further investigation of the anthropogenic and natural factors causing these differences in distribution is needed. Posted: 2008-02-08
Open-File Report 2007-1216: Side-scan Sonar Imaging of the Colorado River, Grand Canyon This paper presents data collection methods and side-scan sonar data collected along the Colorado River in Grand Canyon in August and September of 2000. The purpose of the data collection effort was to image the distribution of sand between Glen Canyon Dam and river mile 87.4 before and after the 31,600 cfs flow of September 6-8. The side-scan sonar imaging focused on pools between rapids but included smaller rapids where possible. Posted: 2008-01-11
USGS Monterey Bay Science USGS Monterey Bay Science - USGS research in the Monterey Bay National Marine Sanctuary and coastal watersheds of central California Posted: 2008-01-01
Open-File Report 2007-1305: Bathymetry, Substrate and Circulation in Westcott Bay, San Juan Islands, Washington Nearshore bathymetry, substrate type, and circulation patterns in Westcott Bay, San Juan Islands, Washington, were mapped using two acoustic sonar systems, video and direct sampling of seafloor sediments. The goal of the project was to characterize nearshore habitat and conditions influencing eelgrass (Z. marina) where extensive loss has occurred since 1995. A principal hypothesis for the loss of eelgrass is a recent decrease in light availability for eelgrass growth due to increase in turbidity associated with either an increase in fine sedimentation or biological productivity within the bay. To explore sources for this fine sediment and turbidity, a dual-frequency Biosonics sonar operating at 200 and 430 kHz was used to map seafloor depth, morphology and vegetation along 69 linear kilometers of the bay. The higher frequency 430 kHz system also provided information on particulate concentrations in the water column. A boat-mounted 600 kHz RDI Acoustic Doppler Current Profiler (ADCP) was used to map current velocity and direction and water column backscatter intensity along another 29 km, with select measurements made to characterize variations in circulation with tides. An underwater video camera was deployed to ground-truth acoustic data. Seventy one sediment samples were collected to quantify sediment grain size distributions across Westcott Bay. Sediment samples were analyzed for grain size at the Western Coastal and Marine Geology Team sediment laboratory in Menlo Park, Calif. These data reveal that the seafloor near the entrance to Westcott Bay is rocky with a complex morphology and covered with dense and diverse benthic vegetation. Current velocities were also measured to be highest at the entrance and along a deep channel extending 1 km into the bay. The substrate is increasingly comprised of finer sediments with distance into Westcott Bay where current velocities are lower. This report describes the data collected and preliminary findings of USGS Cruise B-6-07-PS conducted between May 31, 2007 and June 5, 2007. Posted: 2007-10-18
Open-File Report 2007-1270: High-Resolution Topographic, Bathymetric, and Oceanographic Data for the Pleasure Point Area, Santa Cruz County, California: 2005-2007 The County of Santa Cruz Department of Public Works and the County of Santa Cruz Redevelopment Agency requested the U.S. Geological Survey (USGS) Western Coastal and Marine Geology Team (WCMG) to provide baseline geologic and oceanographic information on the coast and inner shelf at Pleasure Point, Santa Cruz County, California. The rationale for this proposed work is a need to better understand the environmental consequences of a proposed bluff stabilization project on the beach, the nearshore and the surf at Pleasure Point, Santa Cruz County, California. To meet these information needs, the USGS-WCMG Team collected baseline scientific information on the morphology and waves at Pleasure Point. This study provided high-resolution topography of the coastal bluffs and bathymetry of the inner shelf off East Cliff Drive between 32nd Avenue and 41st Avenue. The spatial and temporal variation in waves and their breaking patterns at the study site were documented. Although this project did not actively investigate the impacts of the proposed bluff stabilization project, these data provide the baseline information required for future studies directed toward predicting the impacts of stabilization on the sea cliffs, beach and nearshore sediment profiles, natural rock reef structures, and offshore habitats and resources. They also provide a basis for calculating potential changes to wave transformations into the shore at Pleasure Point. Posted: 2007-10-17
The Coastal Sedimentary System: Northern North Carolina The USGS, in collaboration with the State of North Carolina and university researchers, is studying the coastal sedimentary system of northern North Carolina. The primary objective is to map the regional sedimentary framework of the inner shelf in order to understand recent coastal processes, including erosion and the impacts of shoreline change. Posted: 2007-10-11
Index for Open file report 2005 1071 This USGS Open-File report presents digital sidescan-sonar imagery, digital seismic-reflection data, and descriptions and analyses of piston and gravity cores collected by the USGS in the Gulf of Mexico. These data were collected in water depths greater than 200 m. In addition to the data, the report also contains interpretive overlays dervied from these datasets. Posted: 2007-10-11
USGS OFR 2006-1059: Geologic Interpretation and Multibeam Bathymetry of the Sea floor in Southeastern Long Island Sound, Title Page Digital terrain models (DTMs) produced from multibeam echosounder (MBES) bathymetric data provide valuable base maps for marine geological interpretations (e.g. Todd and others, 1999; Mosher and Thomson, 2002; ten Brink and others, 2004; Poppe and others, 2006a,b). These maps help define the geological variability of the sea floor (one of the primary controls of benthic habitat diversity); improve our understanding of the processes that control the distribution and transport of bottom sediments, the distribution of benthic habitats and associated infaunal community structures; and provide a detailed framework for future research, monitoring, and management activities. Posted: 2007-10-11
U.S. Geological Survey Open-File Report 2005-1048 The imagery, interpretive data layers, and data presented herein were derived from multibeam echo-sounder data collected off Eastern Cape Cod, Massachusetts, and from the stations occupied to verify these acoustic data. The basic data layers show sea-floor topography, sun-illuminated shaded relief, and backscatter intensity; interpretive layers show the distributions of surficial sediment and sedimentary environments. Presented verification data include new and historical sediment grain-size analyses and a gallery of still photographs of the seabed. Posted: 2007-10-11
Open-File Report 2007-1217 - Coastal Processes Study at Ocean Beach, San Francisco, CA: Summary of Data Collection 2004-2006 Ocean Beach in San Francisco, California, contains a persistent erosional section in the shadow of the San Francisco ebb tidal delta and south of Sloat Boulevard that threatens valuable public infrastructure as well as the safe recreational use of the beach. Coastal managers have been discussing potential mediation measures for over a decade, with little scientific research available to aid in decision making. The United States Geological Survey (USGS) initiated the Ocean Beach Coastal Processes Study in April 2004 to provide the scientific knowledge necessary for coastal managers to make informed management decisions. This study integrates a wide range of field data collection and numerical modeling techniques to document nearshore sediment transport processes at the mouth of San Francisco Bay, with emphasis on how these processes relate to erosion at Ocean Beach. The Ocean Beach Coastal Processes Study is the first comprehensive study of coastal processes at the mouth of San Francisco Bay. Posted: 2007-10-04
El Niño Home Page El Niño information with links to a broad range of topics such as Floods, Landslides, Coastal Hazards, Climate, News Releases. Posted: 2007-09-30
General Information Product 54 : Sand Waves at the Mouth of San Francisco Bay, California [Postcard] Postcard: The U.S. Geological Survey; California State University, Monterey Bay; U.S. Army Corps of Engineers; National Oceanic and Atmospheric Administration; and Center for Integrative Coastal Observation, Research and Education partnered to map central San Francisco Bay and its entrance under the Golden Gate Bridge using multibeam echosounders. View eastward, through the Golden Gate into central San Francisco Bay. Depth of sea floor color coded: red (less than 10 m deep) to purple (more than 100 m deep). Land from USGS digital orthophotographs (DOQs) overlaid on USGS digital elevation models (DEMs). Sand waves in this view average 6 m in height and 80 m from crest to crest. Golden Gate Bridge is about 2 km long. Vertical exaggeration is approximately 4x for sea floor, 2x for land. Posted: 2007-09-14
Open-File Report 2007-1169: 2005 Hydrographic Survey of South San Francisco Bay, California USGS report entitled: 2005 Hydrographic Survey of South San Francisco Bay, California; this report documents how the hydrographic survey was conducted, provides an accuracy assessment of the data and distributes the sounding data along with a high-resolution shaded relief map of the bathymetry of South San Francisco Bay. Posted: 2007-07-05
Miscellaneous Field Studies Map MF-2345: Seafloor Rocks and Sediments of the Continental Shelf from Monterey Bay to Point Sur, California Acoustic swath mapping of the greater Monterey Bay area continental shelf from Point Año Nuevo to Point Sur reveals complex patterns of rock outcrops on the shelf, and coarse sand bodies that occur in distinct depressions on the inner and mid-shelves. This publication portrays the seafloor components in a 36- by 48-inch map sheet at 1:100,000 scale. The digital database for the interpreted geology and other digital files are listed and available for download. The explanatory text appears on the map sheet and a copy for download is included. Posted: 2007-04-20
Open-File Report 2006-1180: Digital single-channel seismic-reflection data from western Santa Monica Basin During a collaborative project in 1992, Geological Survey of Canada and United States Geological Survey scientists obtained about 850 line-km of high-quality single-channel boomer and sleeve-gun seismic-reflection profiles across Hueneme, Mugu and Dume submarine fans, Santa Monica Basin, off southern California. The goals of this work were to better understand the processes that lead to the formation of sandy submarine fans and the role of sea-level changes in controlling fan development. This report includes a trackline map of the area surveyed, as well as images of the sleeve-gun profiles and the opportunity to download both images and digital data files (SEG-Y) of all the sleeve-gun profiles. Posted: 2006-12-21
USGS Circular 1198 - Beyond the Golden Gate - Oceanography, Geology, Biology, and Environmental Issues in the Gulf of the Farallones The USGS began a major geologic and oceanographic study of the Gulf of the Farallones in 1989. This investigation, the first of several now being conducted adjacent to major population centers by the USGS, was undertaken to establish a scientific data base for an area of 3,400 square kilometers (1,000 square nautical miles) on the Continental Shelf adjacent to the San Francisco Bay region. The results of this study can be used to evaluate and monitor human impact on the marine environment. Posted: 2006-11-17
Open-File Report 2006-1346 - Swath Bathymetric Survey of Englebright Lake, Yuba-Nevada Counties, California USGS report presenting a bathymetric survey of Englebright Reservoir, located in the Sierra Nevada Foothills of California on the Yuba River. The survey was conducted in May, 2001, and this report presents calculations of volumes of sediment that have accumulated in the lake since dam construction in 1941. Posted: 2006-11-14
Open-File Report 2006-1247: High-resolution chirp seismic reflection data acquired from the Cap de Creus shelf and canyon area, Gulf of Lions, Spain in 2004 This report consists of high-resolution chirp seismic reflection profile data from the northern Gulf of Lions, Spain. These data were acquired in 2004 using the Research Vessel Oceanus (USGS Cruise ID: O-1-04-MS). The data are available in binary and JPEG image formats. Binary data are in Society of Exploration Geologists (SEG) SEG-Y format and may be downloaded for further processing or display. Reference maps and JPEG images of the profiles may be viewed with your Web browser. Posted: 2006-11-02
Maps Showing the Stratigraphic Framework of South Carolina's Long Bay from Little River to Winyah Bay South Carolina's Grand Strand is a heavily populated coastal region that supports a large tourism industry. Like most heavily developed coastal communities, the potential for property damage and lost revenues associated with coastal erosion and vulnerability to severe storms is of great concern. In response to these concerns, the US Geological Survey (USGS) and the South Carolina Sea Grant Consortium have chosen to focus upon the Grand Strand and immediately adjacent Long Bay as a portion of Phase II of the South Carolina/Georgia Coastal Erosion Study (SC/GCES). Posted: 2006-10-20
U.S. Geological Survey Open-File Report 03-221 This report contains descriptions and ancillary information for 62 bedrock cores, most with associated photographs, from western Cape Cod, Massachusetts. Posted: 2006-10-20
USGS Fact Sheet 2005-3041 USGS Fact Sheet 2005-3041: South Carolina Caostal Erosion Study Posted: 2006-10-20
U.S. Geological Survey Open-File Report 2005-1018: Surficial GeologicInterpretation and Sidescan Sonar Imagery of the Sea Floor in West-Central LongIsland 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 grabs, seismic lines, and bottom video, are used to interpret the surficial geology. Posted: 2006-10-20
USGS Open-File Report 2004-1426, RayGUI 2.0, Inversion Ray-Tracing for RAYINVR RayGUI 2.0 is a graphical user interface (GUI) to the seismic travel-time modeling program of Zelt and Smith (1992). RayGUI 2.0 represents a significant improvement over the previous version of RayGUI (RayGUI 1.04; Loss et al., 1998a, b). RayGUI 2.0 uses an updated Java version (1.3), and it can run on various operating systems (UNIX, Linux, and Mac OS X). Several new functions have been incorporated, including: execute the forward and inversion codes of Zelt and Smith (1992), create models or add new parts of models from an ASCII file, graphically add layers or points, graphically pinch layers, change the velocity value of a control point, report point location and velocity, import traveltime lists, generate postscript files, export the velocity model into an ASCII file, generate 1D velocity profiles at specified locations, calculate root-mean-square errors between observed and calculated arrivals for selected phases, access the ray trace log, and several other new display features. Posted: 2006-10-20
USGS Open-File Report 2004-1400 This report contains the documentation and raw data files that were collected between 18 February and 7 March 2003 as part of USGS Cruise 03008 (NOAA Cruise RB0303). It includes archive files of Swath Bathymetric Sonar, CTD/XBT and GPS navigation that were collected in the process of mapping the Puerto Rico Trench. Posted: 2006-10-20
Sea Floor Topography and Backscatter Intensity of the Hudson Canyon Region Offshore of New York and New Jersey, USGS Open-File Report 2004-1441, Title Page This report (available on CD-ROM and on the internet) presents maps of the sea-floor topography and backscatter intensity of the Hudson Canyon region, offshore of New York and New Jersey, USA at a scale of 1:300,000. The maps and geologic interpretation are presented on two sheets in PDF format. Sheet 1 shows sea floor topography as shaded relief. Sheet 2 shows sea floor topography as shaded relief with backscatter intensity superimposed in color. Sheet 1 also contains interpretive text, and both sheets contain figures and tables that further present and describe the data. The interpretive tex can also be viewed in html with links to the figures and tables on the map sheets. The maps are based on new multibeam echo-sounder data collected on an 18-day cruise carried out aboard the National Oceanic and Atmospheric Administration (NOAA) Ship Ronald H. Brown in 2002. Posted: 2006-10-20
U.S. Geological Survey Open-File Report 2004-1435, title page Geophysical analysis of a high-amplitude, negative polarity reflector in the Baltimore Canyon Trough are compatible with it being an autochthonous Aalenian(?) salt lens. Posted: 2006-10-20
USGS OFR 2005-1145: Interpolation of Reconnaissance Multibeam Bathymetry from North-Central Long Island Sound, Title Page This data report contains both the original reconnaissance bathymetry collected during NOAA surveys H11043, H11044, H11045 of north-central Long Island Sound, and interpolated grids and color-encoded hill-shaded imagery produced from the reconnaissance. The report was produced because these bathymetric grids and imagery help define the geological variability of the sea floor, improve our understanding of surficial processes, and provide a detailed framework for future research, monitoring, and management activities. Posted: 2006-10-20
Scientific Investigations Map 2944: Sand Waves at the Mouth of San Francisco Bay, California A multibeam bathymetric survey that produced unprecedented high resolution images of the mouth of San Francisco Bay was conducted in 2004 and 2005. The survey, performed over forty-four days by the Seafloor Mapping Lab at California State University, Monterey Bay, consisted of 1,138 track lines, 1.1 billion soundings, and covered an area of 154 sq. km (60 sq.mi). The goals of this survey were to analyze sediment transport pathways at the mouth of San Francisco Bay and to calculate bathymetric change since the last survey was completed in 1956. The survey showed that significant bathymetric changes have occurred over the past 50 years. It also revealed that the study area contains sand waves that are among the largest and bedform morphologies that are among the most varied in the world. This set of five sheets shows views of the sand waves on the seafloor from different perspectives along with descriptive text. Posted: 2006-10-17
Research Projects - Pleasure Point - USGS WCMG The Santa Cruz County Department of Public Works, the Santa Cruz County Redevelopment Agency and the California Department of Boating and Waterways requested a proposal from the USGS Western Coastal and Marine Geology Team (WCMGT) to provide baseline geologic and oceanographic information on the coast and inner shelf off Pleasure Point, Santa Cruz County, California. To meet these information needs, the USGS has proposed a study to collect baseline scientific information on the morphology and waves at Pleasure Point. This study will provide high-resolution topography of the coastal bluffs and bathymetry of the inner shelf off East Cliff Drive between 32nd Avenue and 41st Avenue (see map below). Further, we will document the spatial and temporal variation in waves at the study site. Although this project will not actively investigate the impacts of the proposed bluff stabilization project, these data will provide the baseline data needed for future studies directed toward predicting the impacts of stabilization on the seacliffs, beach and nearshore sediment profiles, natural rock reef structures, and offshore habitats and resources. It will also provide a basis for calculating potential changes to wave transformations into the shore at Pleasure Point. Posted: 2006-10-17
Research Projects - National Seafloor Mapping and Benthic Habitat Studies: Pacific Geophysical characterization of the coastal sea floor to identify benthic fish and shellfish habitat. Areas include Glacier Bay, Alaska and the Channel Islands National Marine Sanctuary, National Park, and Southern California State Fish Preserves. Posted: 2006-07-17
Scientific Investigations Map 2917: Under the Golden Gate Bridge - Views of the Sea Floor Near the Entrance to San Francisco Bay, California San Francisco Bay in Northern California is one of the largest and most altered estuaries within the United States. The sea floor within the bay as well as at its entrance is constantly changing due to strong tidal currents, aggregate mining, dredge disposal, and the creation of new land using artificial fill. Understanding this dynamic sea floor is critical for addressing local environmental issues, which include defining pollution transport pathways, deciphering tectonics, and identifying benthic habitats. Mapping commercial interests such as safe ship navigation and dredge disposal is also significantly aided by such understanding. Over the past decade, the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), and California State University, Monterey Bay (CSUMB) in cooperation with the U.S. Army Corps of Engineers (USACOE) and the Center for Integrative Coastal Observation, Research and Education (CICORE) have partnered to map central San Francisco Bay and its entrance under the Golden Gate Bridge using multibeam echosounders. These sonar systems can continuously map to produce 100 percent coverage of the sea floor at meter-scale resolution and thus produce an unprecedented view of the floor of the bay. This poster shows views of the sea floor in west-central San Francisco Bay around Alcatraz and Angel Islands, underneath the Golden Gate Bridge, and through its entrance from the Pacific Ocean. The sea floor is portrayed as a shaded relief surface generated from the multibeam data color-coded for depth from light blues for the shallowest values to purples for the deepest. The land regions are portrayed by USGS digital orthophotographs (DOQs) overlaid on USGS digital elevation models (DEMs). The water depths have a 4x vertical exaggeration while the land areas have a 2x vertical exaggeration. Posted: 2006-07-07
CA, OR & WA GLORIA Imagery GLORIA sidescan sonar imagery of the Exclusive Economic Zone of the West Coast of the USA - Washington, Oregon and California. Posted: 2005-09-12
Bering Sea GLORIA Imagery GLORIA sidescan sonar imagery of the Bering Sea, Alaska showing index map and downloadable quadrangles of sea-floor imagery. Posted: 2004-11-15
Predicting the Long-Term Fate of Sediments and Contaminants in Massachusetts Bay - USGS Fact Sheet 172-97 Contaminants have accumulated in the sediments of Massachusetts Bay, typical of many coastal areas near major metropolitan centers that have been used for waste disposal since colonial times. Developing an understanding of where and why contaminants accumulate is essential for making informed management decisions about uses of these coastal areas and for developing sound strategies for monitoring environmental change. Posted: 2004-03-02
Sedimentary Environments in Long Island Sound: A Guide to Sea-Floor Management in a Large Urbanized Estuary - USGS Fact Sheet 041-98 Bottom sedimentary environments, defined by sidescan-sonar patterns, indicate where sea-floor sediments are moved and deposited in the Long Island Sound estuary. The patchy distribution of environments, which reflects both regional and local changes in geologic and oceanographic conditions, provides a predictive framework for those concerned with the management and utilization of the sea floor in this urbanized area. Posted: 2004-03-02
Coastal Erosion of Southern Lake Michigan - USGS Fact Sheet Geological Survey studies the geologic processes at work in the Great Lakes region because they have direct bearing on the use, management, development, and preservation of the shoreline. It is important to understand how these processes shape our daily lives. About 15 percent of the United States' and 50 percent of Canada's population live along or near the 9,000-kilometer-long coastline of the Great Lakes. About 83 percent of the shoreline is privately-owned with property values as high as $10,000 per linear foot of lakefront. Posted: 2004-03-02
The Escanaba Trough of Gorda Ridge: A Laboratory for Mineral-forming Processes
- USGS Fact Sheet The Gorda Ridge is a unique geological system in the Exclusive Economic Zone of the United States. This tectonically and volcanically active plate boundary has an unusual morphology for spreading centers in the Pacific Ocean: a deep, wide axial valley flanked by high ridges. Because of its location near the continental margin, part of the axial valley known as the Escanaba Trough is covered by sediment. The Escanaba Trough provides opportunities for scientists to learn details about tectonics, volcanism, mineral formation, and biological activity that are not normally observed at mid-ocean ridges. It is a geological laboratory of grand proportions. Posted: 2004-03-02
Gas (Methane) Hydrates -- A New Frontier - USGS Fact Sheet Methane trapped in marine sediments as a hydrate represents such an immense carbon reservoir that it must be considered a dominant factor in estimating unconventional energy resources; the role of methane as a 'greenhouse' gas also must be carefully assessed. Posted: 2004-03-02
Geology of the Gulf of the Farallones National Marine Sanctuary - USGS Fact Sheet The geology and oceanography of the Farallones and surrounding area is atypical and complex. These factors complicate the process of understanding the environmental effects of man's influence such as the disposal of dredge spoils and radioactive wastes. Our goal is to assemble, in a non-crisis mode, geological information to support sound management decisions for any purpose. Posted: 2004-03-02
High-Energy Storms Shape Puerto Rico - USGS Fact Sheet Geologists have known for many years that damage inflicted by hurricanes on coastal areas may be less important for the long-term evolution of a coast than the effects of less intense, but more frequent, storm events. Indeed, high-energy storms may be needed to maintain the health of delicate marine ecologies in the coastal environment. Marine geologists of the U.S. Geological Survey working in Puerto Rico are confident that the long-term effects of Hurricane Hugo on the coastal environment are minimal, though the economic damage was significant. Detailed oceanographic studies are needed to define the sediment budget of the nearshore areas of Puerto Rico and to provide baseline information for studying storm effects. Posted: 2004-03-02
Monterey Bay Marine Sanctuary Geological Processes and Framework - USGS Fact Sheet The U.S. Geological Survey (USGS) will move its Pacific Marine Geology program to a new location at the University of California at Santa Cruz (UCSC) and we are excited about our role in the marine sciences community around Monterey Bay. There is much to learn in the region, not only as a result of new opportunities in the Marine Sanctuary, but also that knowledge gained here may be transferred to our studies of similar environments in other parts of the world. Posted: 2004-03-02
Seafloor Images Refine Petroleum Exploration Models - USGS Fact Sheet GLORIA mapping has shown that we need to think again about our conventional models for formation of deep-sea fans. Exploration for hydrocarbon accumulations in ancient fan environments may change dramatically as a consequence of our new understanding of deep-sea fan formation. Posted: 2004-03-02
Seafloor Studies of Mamala Bay, Honolulu, Hawaii: USGS Fact Sheet Disposal of dredge spoils in the near offshore area, coupled with the rapid growth of Honolulu and other nearby municipalities, has placed increased stress on the environment of Mamala Bay. No satisfactory bathymetric map of the seafloor had existed, and little information has been compiled about the effects of these activities to determine whether modifications to the operation and management of the designated dump sites and sewage outfall locations were necessary. Posted: 2004-01-04
Topography, shaded relief, and backscatter intensity of the This CD_ROM presents maps of the sea floor topography, shaded relief, and backscatter intensity of the Hudson Shelf Valley, located offshore of New York and New Jersey, at a scale of 1:150,000 based on multibeam echo-sounder data. The multibeam surveys were conducted aboard the vessel Frederick G. Creed in fall 1996, 1998, and spring 2000. The maps and discussion are presented on two sheets in PDF format. The discussion is also presented in PDF format, with links to individual figures and tables on the map sheet. Posted: 2003-12-01
USGS OFR 03-250 - Bed-Sediment Grain-Size and Morphologic Data from Suisun, Grizzly, and Honker Bays, CA, 1998-2002 The USGS Place Based Studies Program for San Francisco Bay investigates this sensitive estuarine system to aid in resource management. As part of the inter-disciplinary research program, the USGS collected side-scan sonar data and bed-sediment samples from north San Francisco Bay to characterize bed-sediment texture and investigate temporal trends in sedimentation. The study area is located in central California and consists of Suisun Bay, and Grizzly and Honker Bays, sub-embayments of Suisun Bay. During the study (1998-2002), the USGS collected three side-scan sonar data sets and approximately 300 sediment samples. The side-scan data revealed predominantly fine-grained material on the bayfloor. We also mapped five different bottom types from the data set, categorized as featureless, furrows, sand waves, machine-made, and miscellaneous. We performed detailed grain-size and statistical analyses on the sediment samples. Overall, we found that grain size ranged from clay to fine sand, with the coarsest material in the channels and finer material located in the shallow bays. Grain-size analyses revealed high spatial variability in size distributions in the channel areas. In contrast, the shallow regions exhibited low spatial variability and consistent sediment size over time. Posted: 2003-10-29
USGS OFR 03-265 - Grand Canyon Riverbed Sediment Changes, Experimental Release of September 2000 - A Sample Data Set An experimental water release from the Glen Canyon Dam into the Colorado River above Grand Canyon was conducted in September 2000 by the U.S. Bureau of Reclamation. The U.S. Geological Survey (USGS) conducted sidescan sonar surveys between Glen Canyon Dam (mile -15) and Diamond Creek (mile 220), Arizona (mile designations after Stevens, 1998) to determine the sediment characteristics of the Colorado River bed before and after the release. The first survey (R3-00-GC, 28 Aug to 5 Sep 2000) was conducted before the release when the river was at its Low Summer Steady Flow (LSSF) of 8,000 cfs. The second survey (R4-00-GC, 10 to 18 Sep 2000) was conducted immediately after the September 2000 experimental release when the average daily flow was as high as 30,800 cfs as measured below Glen Canyon Dam (Figure 2). Riverbed sediment properties interpreted from the sidescan sonar images include sediment type and sandwaves; overall changes in these properties between the two surveys were calculated. Posted: 2003-10-29
USGS OFR 02-411 - Multibeam Mapping of Selected Areas of the Outer Continental Shelf, Northwestern Gulf of Mexico - Data, Images, and GIS Following the publication of high-resolution (5-meter spatial resolution) multibeam echosounder (MBES) images of the Flower Garden Banks National Marine Sanctuary area of the northwest Gulf of Mexico (Gardner et al., 1998), the Flower Garden Banks National Marine Sanctuary (FGBNMS) and the Minerals Management Service (MMS) have been interested in additional MBES data in the area. A coalition of FGBNMS, MMS, and the US Geological Survey (USGS) was formed to map additional areas of interest in the northwestern Gulf of Mexico (Figure 1) in 2002. FGBNMS chose the survey areas and the USGS chose the MBES. MMS and FGBNMS funded the mapping and the USGS organized the ship and multibeam systems through a cooperative agreement between the USGS and the University of New Brunswick. The objective of the cruise was to map seven regions of interest to MMS and the FGBNMS. This report provides the multibeam bathymetry and acoustic backscatter data, images, FGDC-compliant metadata, and a geographic information system (GIS) project from the 2002 surveys. This report also provides the multibeam bathymetry and acoustic backscatter data, images, and metadata from the 1997 USGS survey of East and West Flower Garden Bank and Stetson Bank. Posted: 2003-10-29
USGS OFR 02-410 - USGS Western Region Coastal and Marine Geology Cruise Report, R/V Ocean Surveyor Cruise O1-02-GM: Bathymetry and Acoustic Backscatter of Selected Areas of the Outer Continental Shelf, Northwestern Gulf of Mexico Following the publication of high-resolution multibeam echosounder (MBES) images and data of the Flower Gardens area of the northwest Gulf of Mexico outer continental shelf (Gardner et al., 1998), the Flower Gardens Banks National Marine Sanctuary (FGBNMS) and the Minerals Management Service (MMS) have been interested in additional MBES data in the area. A coalition of FGBNMS, MMS, and the US Geological Survey (USGS) was formed to map additional areas of interest in the northwestern Gulf of Mexico (Fig. 1) in 2002. The areas were chosen by personnel of the FGBNMS and the choice of MBES was made by the USGS. MMS and FGBNMS funded the mapping and the USGS organized the ship and multibeam systems through a Cooperative Agreement between the USGS and the University of New Brunswick. The University of New Brunswick (UNB) contracted the RV Ocean Surveyor and the EM1000 MBES system from C&C Technologies, Inc., Lafayette, LA. C&C personnel oversaw data collection whereas UNB personnel conducted the cruise and processed all the data. USGS personnel were responsible for the overall cruise including the final data processing and digital map products. Posted: 2003-10-29
USGS OFR 02-396 - Cruise Report: R/V Moana Wave Cruise M-1-02-GM: Bathymetry and Acoustic Backscatter of the Mid and Outer Continental Shelf, Head of De Soto Canyon, Northeastern Gulf of Mexico The mid to outer continental shelf off Mississippi-Alabama and off northwest Florida were the focus of US Geological Survey (USGS) multibeam echosounder (MBES) mapping cruises in 2000 and 2001, respectively. These areas were mapped to investigate the extent of "deep-water reefs" first suggested by Ludwick and Walton (1957). The reefs off Mississippi and Alabama were initially described in water depths of 60 to 120 m (Ludwick and Walton, 1957) but the 2000 mapping found reef and hardgrounds to be much more extensive than previously thought (Gardner et al., 2001). The persistent trend of reef-like features along the outer shelf of Mississippi-Alabama suggested the trend might continue along the northwest Florida mid and outer shelf so a MBES-mapping effort was mounted in 2001 to test this suggestion. It is critical to determine the accurate location, geomorphology, and types of the ridges and reefs that occur in this region to understand the Quaternary history of the area and to assess their importance as benthic habitats for fisheries. The 2001 survey found a series of shelf-depth platforms with ridges (possibly reefs) constructed on their surfaces (Gardner et al., 2002). Posted: 2003-10-29
USGS OFR 02-391 - USGS Western Region Coastal and Marine Geology, Multibeam Bathymetry and Selected Perspective Views of Main Part of Glacier Bay, Alaska Glacier Bay is a diverse fjord ecosystem with multiple tidewater glaciers and complex biological, geological, and oceanographic patterns that vary greatly along its length. The bay was completely glaciated prior to the 1700's, and subsequently experienced the fastest glacial retreat recorded in historical times (Fig. 1). As a result, some of the highest rates of glacial sedimentation and uplift are observed here. Glacier Bay is the deepest silled fjord in Alaska, with depths of over 450 meters. The variety of physical processes (for example icebergs gouging, see Fig. 2) and depths creates many diverse habitats within a relatively small area. Mapping benthic (seafloor) habitats is thus crucial to understanding and managing Glacier Bay's complex marine ecosystem and the marine species therein. High-resolution multibeam mapping of the bay, funded jointly by USGS and the National Park System, provides an unprecedented new baseline for resource and habitat assessment. Full integration of the new data set will require additional ground-truthing data (sampling) and analysis. The USGS goal is to develop integrated geological and oceanographic habitat models for the marine benthos in Glacier Bay, as a step toward determining the habitat relationships of critical species and resources within the Park. This Open-File Report publishes the multibeam bathymetry along with images. Posted: 2003-10-29
USGS OFR 03-110 - Cruise Report for A1-02-SC: Southern California CABRILLO project, Earthquake Hazards Task A two-week marine geophysical survey obtained sidescan-sonar images and multiple sets of high-resolution seismic-reflection profiles in the southern California offshore area between Point Arguello and Point Dume. The data were obtained to support two project activities of the United States Geological Survey (USGS) Coastal and Marine Geology (CMG) Program: (1) the evaluation of the geologic hazards posed by earthquake faults and landslides in the offshore areas of Santa Barbara Channel and western Santa Monica Basin and (2) determine the location of active hydrocarbon seeps in the vicinity of Point Conception as part of a collaborative study with the Minerals Management Service (MMS). The 2002 cruise, A1-02- SC, is the fourth major data-collection effort in support of the first objective (Normark et al., 1999a, b; Gutmacher et al., 2000). A cruise to obtain sediment cores to constrain the timing of deformation interpreted from the geophysical records is planned for the summer of 2003. Posted: 2003-10-01
USGS I Map 2790 - Crater Lake Revealed Recently, the bottom of Crater Lake, Oregon was mapped with a high-resolution multibeam echo sounder. The new bathymetric survey provides a 2m/pixel view of the lake floor from its deepest basins virtually to the shoreline. Using Geographic Information Systems (GIS) applications, the bathymetry data can be visualized and analyzed to shed light on the geology, geomorphology, and geologic history of Crater Lake. Posted: 2003-10-01
Saltwater Intrusion in Los Angeles Area Coastal Aquifers--the Marine Connection | FS 030-02 One-third of the water supply for coastal areas of Greater Los Angeles comes from local ground-water sources. Saltwater has penetrated a part of the supply, and a significant part of the remaining supply is at risk. U.S. Geological Survey scientists, working in cooperation with local water agencies, are studying the connection between coastal aquifers and the offshore geology to better understand the processes and pathways of saltwater intrusion. Posted: 2003-03-18
New Mapping Techniques Help Assess the Health of Hawai'i's Coral Reefs
| USGS Fact Sheet 084-01 More than 60% of coral reefs in U.S. waters are found in the extended Hawaiian Island chain. These complex and diverse marine ecosystems are not only ecologically important but also provide hundreds of millions of dollars annually to Hawai‘i’s economy. Elsewhere in the world, corals are dying at unprecedented rates, and the reefs of Hawai‘i may also be at risk. To monitor and protect these reefs and to help understand what is threatening coral-reef habitats worldwide, U.S. Geological Survey (USGS) and other scientists are using new techniques to create detailed maps of Hawai‘i’s coral reefs. Posted: 2003-03-18
West-Central Florida Coastal Transect #3: Sand Key - USGS Open File Report 99-507 This is the third of nine transect areas extending from the mainland of west-central Florida out to a depth of 26m. Data collected and presented includes sediment core data and side-scan sonar mapping of portions of the seafloor. Posted: 2002-12-17
West-Central Florida Coastal Transect #8: Siesta Key - USGS Open File Report 99-512 This is the eighth of nine transect areas extending from the mainland of west-central Florida out to a depth of 26m. Data collected and presented includes sediment core data and side-scan sonar mapping of portions of the seafloor. Posted: 2002-12-17
West-Central Florida Coastal Transect #9: Casey Key - USGS Open File Report 99-513 This is the ninth of nine transect areas extending from the mainland of west-central Florida out to a depth of 26m. Data collected and presented includes sediment core data and side-scan sonar mapping of portions of the seafloor. Posted: 2002-12-17
U.S. Geological Survey - Historic Area Remediation Site (HARS) Web Page Three multibeam echosounder surveys were carried out to map the topography and surficial geology of the Historic Area Remediation Site (HARS) located offshore of New York City. The surveys were conducted November 23 - December 3, 1996, October 26 - November 11, 1998, and April 6 - 30, 2000. This report presents maps showing topography, shaded relief, and backscatter intensity (a measure of sea floor texture and roughness) at a scale of 1:25,000. Comparison of the topography and backscatter intensity from the three surveys show changes in topography and surficial sediment properties resulting from placement of dredged material in 1996 and 1997 prior to closure of the Mud Dump Site, as well as placement of capping material for remediation of the HARS. Posted: 2002-07-09
USGS Sediment Studies in Lake Mead Lake Mead is one of the world's largest man-made reservoirs at about 600 sq km, roughly the size of Chicago. Lake Mead started to form on the Colorado River in 1935, upon completion of the Hoover Dam. Since then, the lake has supplied water to agricultural, industrial, recreational, and municipal users in the southwestern United States. Posted: 2002-05-15
Technology for Seafloor Mapping A description of the instruments and techniques used by a USGS group to map the sea floor. Discusses how echo sounding, sidescan sonar, and seismic reflection data are gathered and processed to learn about sea floor features, sediments, and sub-bottom structure. Posted: 2002-04-24
Multibeam Bathymetric and Backscatter Maps of the Upper Hudson Shelf Valley and Adjacent Shelf, Offshore of New York About aproject to map the surficial geology and subsurface stratigraphy of the Hudson Shelf Valley and adjacent continental shelf from its head near New York Harbor to where it crosses the outer. The northwesterly area of the survey encompasses a region of the shelf that may provide sediment to the valley as well as the principal disposal sites used since the 1800's. Posted: 2002-04-24
Sidescan-Sonar Imagery of the Shoreface and Inner Continental Shelf, Wrightsville Beach, North Carolina The geologic framework and surficial morphology of the shoreface and inner shelf off Wrightsville Beach, North Carolina, were mapped using high-resolution sidescan-sonar, bathymetric, and seismic-reflection surveying techniques, a suite of over 200 diver-vibracores, and extensive sea-floor observations by divers. The inner shelf is a sediment-starved, active surface of marine erosion; modern sediments, where present, form a thin, patchy veneer blanketing Tertiary and Quaternary units. Posted: 2002-04-24
Gulf of Mexico GLORIA Sidescan Sonar Geologic Interpretation This (online) CD-ROM contains copies of the 250 m resolution GLORIA sidescan sonar mosaic for the Gulf of Mexico and its geologic interpretation. The imagery and interpretation have been archived here to preserve this legacy data set. The data are intended to be GIS-ready in as much as the data do not require any additional cleanup, formatting, renaming of fields or other "data work" to use the data in the GIS of choice. Posted: 2002-04-24
USGS Studies in Long Island Sound: Geology, Contaminants, and Environmental Issues Long Island Sound is a major coastal estuary near the New York-Connecticut metropolitan area. More than eight million people live in its watershed. Due to the enormous population, the Sound is used heavily and its sea floor has been impacted by human activities. There are many benthic habitats in the Sound that support large commercial and recreational fisheries. Sediments of the Sound are a sink for wastes and contaminants from various sources such as wastewater treatment plants, urban and agricultural runoff, and waste disposal. Posted: 2002-04-24
Boston Harbor/ Massachusetts Bay Studies Environmental effects of the Boston sewage outfall tunnel are being studied using computer simulations of ocean circulation and dilution of sewage from the tunnel, also mapping and sediment analyses to find the pathways and ultimate repositories of contaminants from the Boston Metropolitan area, and monitoring to establish a baseline of contaminant levels in sediments and to document their natural variability. Posted: 2002-04-23
Seafloor Characterization Offshore New York-New Jersey Metropolitan Area using sidescan sonar A preliminary synthesis of systematic high-resolution mapping of the sea floor in the New York Bight Apex, using sidescan-sonar and seismic-reflection profiles. The survey provides a new and detailed view of the sea floor, and a new framework for understanding the regional sediment transport system of the New York Bight. Posted: 2002-04-23
Long Island Sound Environmental Studies Reports and maps on acoustic and textural features of Long Island Sound bottom sediments; Sidescan-sonar imagery of areas off Hammonasset Beach state park, Norwalk, Niantic Bay, Milford, Fishers Island Sound, Falkner Island, New Haven, New London, CT, and Roanoke Pt., NY. Also, articles on a surficial sediment data, benthic communities and contaminants, and currents, and a bibliography. Posted: 2002-04-23
Georeferenced Sea-Floor Mapping and Bottom Photography in Long Island Sound Extensive information in 12 separate chapters on geology (including late-Pleistocene stratigraphy, and a free-air gravity anomaly map indicative deep substructure), surface sediments, organic carbon, benthic enviroments, megafaunal environments, contaminanats such as metals, mercury, and a bacterial indicator of human pollution; GIS referenced mapping data, and a collection of bottom photographs; Environmental changes 1940s to 1990s. Posted: 2002-04-23
Lake Pontchartrain, LA, Geochemistry Geology, geologic history, sediments, circulation, satellite imagery, of Lake Pontchartrain, LA, and a sediment database and geochemical assessment of the Lake. Posted: 2002-04-23
Seafloor Sediment Distribution Off Southern Long Island, New York The late Holocene evolution of the Fire Island barrier-island is linked directly to the geologic framework of the inner-continental shelf. Mapping results show that the modern physiography of the inner-continental shelf off southern Long Island is an expression of antecedent geology and glacial history, as well as oceanographic processes acting on the sea floor during Holocene marine transgression. The upper surface of the Cretaceous strata provided the foundation for deposition of Quaternary sediment and formed the core of a subaerial headland off Watch Hill during times of lower sea level. The modern sediment deposit was formed from erosion of both the headland areas east of Southampton and off Watch Hill and the inner-continental shelf during Holocene marine transgression. Posted: 2002-04-23
SeaMARC 1A sidescan sonar mosaic, cores and depositional interpretation of the Mississippi Fan: ArcView GIS Data Release An online CDROM contains a SeaMARC 1A sidescan sonar mosaic, cores, and a depositional interpretation of the Mississippi Fan, with an ArcView GIS Data Release. This study focused on a depositional lobe identified in previous GLORIA imagery. A channel and breached levee were studied to understand the processes by which sedimentation is redirected to a different part of the fan. The channel that originated at the breach in the levee of the main channel was traced to the distal edge of the Mississippi Fan where deposits associated with the end of this channel system were mapped. Posted: 2002-04-23
Stellwagen Bank National Marine Sanctuary - off Boston MA - Sea Floor topographic contours maps and perspective views A multibeam echo sounder aboard the Canadian Hydrographic Survey vessel Frederick G. Creed mapped the Stellwagen bank area (covering 1100 sq. nautical miles). Topographic contour maps and perspective maps -displayed as sun-illuminated seabed imagery - show sea floor topography (scale of 1:25,000) show the complex sea floor created by glacial erosion, deposition, and subsequent wave and current action. GIS data of the maps are included. Posted: 2002-04-22
Hawaiian Islands GLORIA Imagery GLORIA sidescan sonar imagery of the Hawaiian Islands, showing index map and downloadable quadrangles of sea-floor imagery. Posted: 2002-04-03
U.S. Geological Survey Open-File Report 00-410 Sea floor features of the Stellwagen Bank National Marine Sanctuary region at a scale of 1:60,000. The maps depict topography, sun-illuminated (shaded relief) topographic imagery, and combined imagery of sun-illuminated sea floor topography and backscatter intensity Posted: 2002-03-22
U.S. Geological Survey Studies in the New York Bight Since 1992, the U.S. Geological Survey`s Coastal and Marine Geology Program has been conducting studies offshore of New York designed to map and characterize the sea floor, to understand the transport and fate of sediments and associated pollutants, to map the inner shelf and sand deposits along the southern shore of Long Island, and to understand the recent geologic history. A long-term goal of these geological studies is to develop predictive models and geologic information to guide research and sustainable use of the coastal ocean. Posted: 2001-12-14
West-Central Florida Coastal Studies This project is a study of the west central Florida coast, conducted by the U.S. Geological Survey, University of South Florida, and Eckerd College. The study investigates the formation and maintanance of the barrier island system, as well as the geologic framework of the region. Posted: 2001-10-31
A Marine GIS Library for Massachusetts Bay: This CD-ROM contains information in a Geographic Information System (GIS) format (ESRI's ArcView) for the coastal region offshore of Boston, Massachusetts. This collection of coverages (here defined as ArcView shapefiles, grids and TIFs) is a beginning effort to develop a library of information in GIS format that can be referenced and shared by those working in, and seeking to understand, the Massachusetts Bay region. The CD-ROM was assembled at a workshop attended by an ad-hoc group representing federal and state government, industry and academia. This CD-ROM principally contains data on waste disposal sites and characteristics of the sea floor. Posted: 2001-10-15
U.S. Geological Survey Open-File Report 00-352 USGS Open-File Report 00-352; SeaMARC 1A sidescan sonar mosaic, cores and depositional interpretation of the Mississippi Fan: ArcView GIS Data Release Posted: 2001-10-10
Surficial Geology and Distribution of Post-Impoundment Sediment in Las Vegas Bay, Lake Mead, U.S. Geological Open-File Report 01-070, Title Page Sidescan sonar imagery and seismic-reflection profiles were collected in the northwestern part of Las Vegas Bay to map the distribution and volume of sediment that has accumulated in this part of Lake Mead since impoundment. The mapping suggests that three ephemeral streams are the primary source of this sediment, and of these, Las Vegas Wash is the largest. Two deltas off the mouth of Las Vegas Wash formed at different lake elevations and account for 41% of the total volume of post-impoundment sediment within the study area. Deltas off the other two washes (Gypsum and Government) account for only 6% of the total volume. The sediment beyond the front of the deltas is primarily mud, and it only occurs in valley floors, where it forms a flat-lying blanket that is mostly less than 1.5 m thick. Although a thin layer, the fine-grained sediment accounts for approximately 53% of the total post-impoundment sediment volume of 5.7 x 106 m3 that has accumulated in the study area. This sediment appears to have been transported several kilometers from the river sources by density flows. Posted: 2001-09-07
Global Inventory of Natural Gas Hydrate Occurance This updated global inventory reports on natural gas hydrate recovered from 20 places worldwide and includes 79 places where the presence of gas hydrate has been inferred from geophysical, geochemical, or geological evidence. Posted: 2001-01-09
Great Lakes Mapping Project Initiative to map lake bathymetry and classify lakebed materials to advance knowledge of Great Lakes and enable better management of Great Lakes resources. Posted: 2000-12-12
Education and Outreach Information Helpful information about Activities at the USGS Western Region Coastal and Marine Geology Team. Posted: 2000-11-20
San Francisco Bay Earthquake Hazards Project Earthquake Hazard Studies in the San Francisco Bay area, including monitoring of faults through seismic imaging and other geophysical studies. Posted: 2000-07-25
Gulf of the Farallones Waste-Disposal Issues Studies about disposal of radioactive waste and dredged material in the Gulf of the Farallones National Marine Sanctuary, offshore of San Francisco, California Posted: 2000-07-19
Seismic Stratigraphy of the Central Indian River Region - Open File Report 97-723 The geology and and hydrology of the central Indian River region along the central east coast of Florida is of critical concern to the St. Johns River Water Management District (SJRWMD). In this area the upward migration of deeper, more saline ground water in the lower Floridan aquifer to the shallower, fresher ground water of the upper Floridan aquifer and above, may impact the water quality of this resource. Posted: 2000-02-29
Gas Hydrates in the Gulf of Mexico Investigation of potential gas-hydrate deposits and possible links between hydrate occurrence and sea-floor failures using remote-sensing technology. Posted: 1999-09-22
Monterey Bay Marine Sanctuary Studies The USGS Monterey Bay National Marine Sanctuary Project gathers, interprets, and distributes geologic information - tools necessary for sound resource protection and preservation of the federally established Monterey Bay National Marine Sanctuary. This web site provides access to that information. Posted: 1999-02-22
Sea-floor Morphology between Año Nuevo and Santa Cruz, California Seafloor map displaying submarine rock exposures found along the northern part of Monterey Bay National Marine Sanctuary, with interpretations of side-scan sonar records, seismic-reflection records, and underwater video. Posted: 1999-02-22
Hydrocarbons in Monterey Bay Marine Sanctuary Description and interpretation of hydrocarbons associated with fluid venting processes in Monterey Bay, California. Posted: 1999-02-17
Massachusetts Bay Seafloor: Mapping Sedimentary Environments The modern seafloor sedimentary environments within the glaciated, topographically complex Boston Harbor and Massachusetts Bay area have been interpreted and mapped from an extensive collection of sidescan sonar records and supplemental marine geologic data. These data outline three categories of sedimentary environments that reflect the predominant long-term processes of erosion, deposition, and sediment reworking. Posted: 1999-01-21
South Carolina Quaternary Geologic Framework South Carolina's central coast and inner shelf from North Edisto River to Bull's Inlet has a complex Quaternary history of transgressive and regressive sedimentary sequences. These sequences were identified from 612 line-km of high-solution single-channel seismic profiles, side-scan sonar mosaics, 81 vibracores, ground penetrating radar, Amino acid racemization, and compilation of previous investigations. Posted: 1998-11-20
Gorda Ridge Hydrothermal System Investigation of distribution, quantity, and composition of hydrothermal deposits along the Gorda Ridge, off the coast of Oregon. Posted: 1998-06-10
USGS TerraWeb: San Francisco Bay - Multibeam Backscatter Data: Alcatraz Island and West-Central Bay Areas Remote sensing in the Central San Francisco Bay Region, featuring multibeam backscatter and bathymetry mosaics products enhanced with satellite imagery. The image maps featured were created to help study sediment and pollutant transport in Central San Francisco Bay -- visit this page for links to the Sediment and Pollutant Trasport project and related web pages. Posted: 1998-05-20
Marine Geology of Benthic Biohabitats in Glacier Bay, Alaska A project to characterize the seafloor habitats in Glacier Bay, Alaska, including geomorphic, sedimentologic, and stratigraphic descriptions, based on acoustic imaging and profiling of the fjord floor Posted: 1998-03-26
Grand Canyon Colorado River Studies Studies of sediment transport in the Grand Canyon, Arizona - using ocean research techniques to study a river system. Posted: 1997-06-09
OFR 95-838: Moored Array Data Report for Monterey Bay, California A study of the mechanisms that govern the circulation within and the transport of sediment and water through Monterey Submarine Canyon using moorings that measured current, temperature, salinity and water clarity Posted: 1996-03-25
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