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Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

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At least 73 records · Page 4Linked to original sources
USGS2003

An acoustic doppler current profiler survey of flow velocities in Detroit River, a connecting channel of the Great Lakes

Acoustic Doppler current profilers (ADCP) were used to survey flow velocities in Detroit River from July 8-19, 2002, as part of a study to assess the susceptibility of public water intakes to contaminants on the St. Clair-Detroit River Waterway. More than 3.5 million point velocities were measured at 130 cross sections. Cross sections were generally spaced about 1,800 ft apart along the river from the head of Detroit River at the outlet of Lake St. Clair to the mouth of Detroit River on Lake Erie. Two transects were surveyed at each cross section, one in each direction across the river. Along each transect, velocity profiles were generally obtained 0.8-2.2 ft apart. At each velocity profile, average water velocity data were obtained at 1.64 ft intervals of depth. The raw position and velocity data from the ADCP field survey were adjusted for local magnetic anomalies using global positioning system (GPS) measurements at the end points of the transects. The adjusted velocity and ancillary data can be retrieved though the internet and extracted to column-oriented data files.

Open-File Report↗
USGS2014

Surface wave site characterization at 27 locations near Boston, Massachusetts, including 2 strong-motion stations

The geotechnical properties of the soils in and around Boston, Massachusetts, have been extensively studied. This is partly due to the importance of the Boston Blue Clay and the extent of landfill in the Boston area. Although New England is not a region that is typically associated with seismic hazards, there have been several historical earthquakes that have caused significant ground shaking (for example, see Street and Lacroix, 1979; Ebel, 1996; Ebel, 2006). The possibility of strong ground shaking, along with heightened vulnerability from unreinforced masonry buildings, motivates further investigation of seismic hazards throughout New England. Important studies that are pertinent to seismic hazards in New England include source-parameter studies (Somerville and others, 1987; Boore and others, 2010), wave-propagation studies (Frankel, 1991; Viegas and others, 2010), empirical ground-motion prediction equations (GMPE) for computing ground-motion intensity (Tavakoli and Pezeshk, 2005; Atkinson and Boore, 2006), site-response studies (Hayles and others, 2001; Ebel and Kim, 2006), and liquefaction studies (Brankman and Baise, 2008). The shear-wave velocity (VS) profiles collected for this report are pertinent to the GMPE, site response, and liquefaction aspects of seismic hazards in the greater Boston area. Besides the application of these data for the Boston region, the data may be applicable throughout New England, through correlations with geologic units (similar to Ebel and Kim, 2006) or correlations with topographic slope (Wald and Allen, 2007), because few VS measurements are available in stable tectonic regions. Ebel and Hart (2001) used felt earthquake reports to infer amplification patterns throughout the greater Boston region and noted spatial correspondence with the dominant period and amplification factors obtained from ambient noise (horizontal-to-vertical ratios) by Kummer (1998). Britton (2003) compiled geotechnical borings in the area and produced a microzonation map based on generalized velocity profiles, where the amplifications were computed using Shake (Schnable and others, 1972), along with an assumed input ground motion. The velocities were constrained by only a few local measurements associated with the Central Artery/Tunnel project. The additional VS measurements presented in this report provide a number of benefits. First, these measurements provide improved spatial coverage. Second, the larger sample size provides better constraints on the mean and variance of the VS distribution for each layer, which may be paired with a three-dimensional (3D) model of the stratigraphy to generate one-dimensional (1D) profiles for use in a standard site-response analysis (for example, Britton, 2003). Third, the velocity profiles may also be used, along with a 3D model of the stratigraphy, as input into a 3D simulation of the ground motion to investigate the effects of basin-generated surface waves and the potential focusing of seismic waves. This report begins with a short review of the geology of the study area and the field methods that we used to estimate the velocity profiles. The raw data, processed data, and the interpreted VS profiles are given in appendix 1. Photographs and descriptions of the sites are provided in appendix 2.

Massachusetts↗
USGS1980

Data-base system for northern Midwest regional aquifer-system analysis

The U.S. Geological Survey is conducting a study of the Cambrian and Ordovician aquifer system of the northern Midwest as part of a national series of Regional Aquifer-Systems Analysis (RASA). An integral part of this study will be a simulation of the ground-water flow regime using the Geological Survey's three-dimensional finite-difference model. The first step in the modeling effort is the design and development of a systematic set of processes to facilitate the collection, evaluation, manipulation, and use of large quantities of information. A computerized data-base system to accomplish these goals has been completed for the northern Midwest RASA. The input to the data-base system consists of either point values or contour maps of the hydrogeologic data required by the model. Digital samples of contoured surfaces are obtained by machine digitization. Uniformly spaced model-node values are then computed from the discrete data by two-dimensional interpolation. The interpolator uses the regional (long wavelength) characteristics of the data to compute a surface with minimum total curvature. Local (short wavelength) data are merged with the regional surface to produce the model-node values at the desired spacing. Nonuniformly spaced nodal values may be obtained by fitting two-dimensional polynomials (bicubic splines) to surfaces formed by uniformly spaced points and solving for the surface values at the node locations. The uniformly or nonuniformly spaced node values constitute the output of the data-base system and in turn are the input arrays of data values for the ground-water flow model. Management of the data base is facilitated by forming a data file for each model input parameter and for other hydrogeologic data used in the study. The data files are subdivided into elements consisting of individual model-layer arrays. In this form the data base can be readily accessed and edited. In addition to the interpolation programs, software components of the system include programs: (1) to transform geographic coordinates on a Lambert conformal conic projection to cartesian coordinates and vice versa, (2) to machine contour gridded data, (3) to expedite manipulation and editing of data, and (4) to perform various interarray computations. The data-base system has the following attributes: (1) manual handling of data is minimized and machine handling of data is maximized, (2) given unequally spaced point data over the extent of a study area, model input arrays for any reasonable uniform node spacing can be rapidly computed, (3) accuracy of computed node values are generally compatible with accuracy and spatial distribution of point data, (4) a relatively large class of nonuniformly spaced node configurations can be computed, (5) data within data-base files can be easily accessed and readily edited, and (6) the occurrence of data processing errors at various stages of data-base generation is monitored by machine contouring the computed grids. Functioning of the data-base system is illustrated by the sequence of steps required to produce a model-input array of transmissivity, given raw geologic and hydraulic conductivity data.

Water-Resources Investigations Report↗
USGS1954

Geologic maps of the Eureka Gulch area, Central City district, Gilpin County, Colorado

These maps are of the historic Eureka Gulch area of the Central City silver district, southern Gilpin County, Colorado. The mapping was done on behalf of the Division of Raw Materials of the U. S. Atomic Energy Commission, as part of a study of the Central City and Idaho Springs districts and was designed to furnish geologic data for use in appraising the uranium reserves of the area.

Colorado↗
USGS2013

New service interface for River Forecasting Center derived quantitative precipitation estimates

For more than a decade, the National Weather Service (NWS) River Forecast Centers (RFCs) have been estimating spatially distributed rainfall by applying quality-control procedures to radar-indicated rainfall estimates in the eastern United States and other best practices in the western United States to producea national Quantitative Precipitation Estimate (QPE) (National Weather Service, 2013). The availability of archives of QPE information for analytical purposes has been limited to manual requests for access to raw binary file formats that are difficult for scientists who are not in the climatic sciences to work with. The NWS provided the QPE archives to the U.S. Geological Survey (USGS), and the contents of the real-time feed from the RFCs are being saved by the USGS for incorporation into the archives. The USGS has applied time-series aggregation and added latitude-longitude coordinate variables to publish the RFC QPE data. Web services provide users with direct (index-based) data access, rendered visualizations of the data, and resampled raster representations of the source data in common geographic information formats.

Fact Sheet↗
USGS2011

Global multi-resolution terrain elevation data 2010 (GMTED2010)

In 1996, the U.S. Geological Survey (USGS) developed a global topographic elevation model designated as GTOPO30 at a horizontal resolution of 30 arc-seconds for the entire Earth. Because no single source of topographic information covered the entire land surface, GTOPO30 was derived from eight raster and vector sources that included a substantial amount of U.S. Defense Mapping Agency data. The quality of the elevation data in GTOPO30 varies widely; there are no spatially-referenced metadata, and the major topographic features such as ridgelines and valleys are not well represented. Despite its coarse resolution and limited attributes, GTOPO30 has been widely used for a variety of hydrological, climatological, and geomorphological applications as well as military applications, where a regional, continental, or global scale topographic model is required. These applications have ranged from delineating drainage networks and watersheds to using digital elevation data for the extraction of topographic structure and three-dimensional (3D) visualization exercises (Jenson and Domingue, 1988; Verdin and Greenlee, 1996; Lehner and others, 2008). Many of the fundamental geophysical processes active at the Earth's surface are controlled or strongly influenced by topography, thus the critical need for high-quality terrain data (Gesch, 1994). U.S. Department of Defense requirements for mission planning, geographic registration of remotely sensed imagery, terrain visualization, and map production are similarly dependent on global topographic data. Since the time GTOPO30 was completed, the availability of higher-quality elevation data over large geographic areas has improved markedly. New data sources include global Digital Terrain Elevation Data (DTEDRegistered) from the Shuttle Radar Topography Mission (SRTM), Canadian elevation data, and data from the Ice, Cloud, and land Elevation Satellite (ICESat). Given the widespread use of GTOPO30 and the equivalent 30-arc-second DTEDRegistered level 0, the USGS and the National Geospatial-Intelligence Agency (NGA) have collaborated to produce an enhanced replacement for GTOPO30, the Global Land One-km Base Elevation (GLOBE) model and other comparable 30-arc-second-resolution global models, using the best available data. The new model is called the Global Multi-resolution Terrain Elevation Data 2010, or GMTED2010 for short. This suite of products at three different resolutions (approximately 1,000, 500, and 250 meters) is designed to support many applications directly by providing users with generic products (for example, maximum, minimum, and median elevations) that have been derived directly from the raw input data that would not be available to the general user or would be very costly and time-consuming to produce for individual applications. The source of all the elevation data is captured in metadata for reference purposes. It is also hoped that as better data become available in the future, the GMTED2010 model will be updated.

Open-File Report↗
USGS2009

Particle Size Characterization of Water-Elutriated Libby Amphibole 2000 and RTI International Amosite

This report presents data on particle characterization analyzed by scanning electron microscopy on Libby amphibole collected by the U.S. Geological Survey in 2000 (LA2000) and amosite material collected by RTI International (RTI amosite). The particle characterization data were generated to support a portion of the Libby Action Plan. Prior to analysis, the raw LA2000 and RTI amosite materials were subjected to a preparation step. Each sample was water-elutriated by U.S. Environmental Protection Agency (USEPA) Office of Research and Development, Research Triangle Park using the methods generally described in another published report and then delivered to the U.S. Geological Survey, Denver Microbeam Laboratory for analysis. Data presented here represent analyses performed by the U.S. Geological Survey, Denver Microbeam Laboratory and USEPA National Enforcement Investigations Center. This report consists of two Excel spreadsheet files developed by USEPA, Region 8 Superfund Technical Assistance Unit and describe the particle size characterization of the LA2000 and RTI amosite, respectively. Multiple tabs and data entry cells exist in each spreadsheet and are defined herein.

Open-File Report↗
USGS2020

Field comparison of five in situ turbidity sensors

Five commercially available turbidity sensors were field tested by the U.S. Geological Survey Hydrologic Instrumentation Facility for accuracy and data comparability. The tested sensors were the Xylem EXO (EXO), the Hach Solitax sc (Solitax), the In Situ Aqua TROLL sensor installed onto a TROLL 600 sonde (TROLL 600), the Campbell Scientific OBS501 (OBS501), and the Observator ANALITE NEP–5000 (NEP–5000). The sensors were deployed at Pearl River at National Space Technology Laboratories Station, Mississippi (U.S. Geological Survey site 02492620), and were serviced weekly. In addition to the five in situ turbidity sensors, corresponding discrete samples were collected and analyzed during the evaluation on a calibrated Hach 2100N benchtop turbidimeter. The OBS501 malfunctioned early in the evaluation and eventually failed, resulting in few data from the sensor. During this study, the four remaining sensors (minus the OBS501) changed similarly throughout the field test; however, sensor data from the EXO consistently demonstrated lower results than the Solitax, TROLL 600, and NEP–5000, possibly because of the variation in raw signal processing among manufacturers. Results from a single factor analysis of variance test and a Tukey Honestly Significant Difference test verified the low bias observed in the EXO data and indicated there was a significant difference between the EXO data and data from the Solitax, TROLL 600, and NEP–5000 but an insignificant difference among the data when the Solitax, TROLL 600, and NEP–5000 were compared to each other.

Mississippi↗
USGS2013

Satellite images of the September 2013 flood event in Lyons, Colorado

The U.S. Geological Survey (USGS) Special Applications Science Center (SASC) produced an image base map showing high-resolution remotely sensed data over Lyons, Colorado—a city that was severely affected by the flood event that occurred throughout much of the Colorado Front Range in September of 2013. The 0.5-meter WorldView-2 data products were created from imagery collected by DigitalGlobe on September 13 and September 24, 2013, during and following the flood event. The images shown on this map were created to support flood response efforts, specifically for use in determining damage assessment and mitigation decisions. The raw, unprocessed imagery were orthorectified and pan-sharpened to enhance mapping accuracy and spatial resolution, and reproduced onto a cartographic base map. These maps are intended to provide a snapshot representation of post-flood ground conditions, which may be useful to decisionmakers and the general public. The SASC also provided data processing and analysis support for other Colorado flood-affected areas by creating cartographic products, geo-corrected electro-optical and radar image mosaics, and GIS water cover files for use by the Colorado National Guard, the National Park Service, the U.S. Forest Service, and the flood response community. All products for this International Charter event were uploaded to the USGS Hazards Data Distribution System (HDDS) website (http://hdds.usgs.gov/hdds2/) for distribution.

Colorado↗
USGS1974

South Carolina seismic program

The principal objectives of the South Carolina Seismic Program are to: (1) provide essential high-quality raw seismic data for earthquakes in South Carolina; (2) compute accurate estimates of event and source parameters; (3) provide a catalog of events and source parameters that will be used in further evaluation of seismic hazard; and (4) respond with rapid estimates of event parameters if a large event occurs within South Carolina during the duration of the program.

South Carolina↗
USGS2014

Geologic field notes and geochemical analyses of outcrop and drill core from Mesoproterozoic rocks and iron-oxide deposits and prospects of southeast Missouri

The U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources/Missouri Geological Survey, undertook a study from 1988 to 1994 on the iron-oxide deposits and their host Mesoproterozoic igneous rocks in southeastern Missouri. The project resulted in an improvement of our understanding of the geologic setting, mode of formation, and the composition of many of the known deposits and prospects and the associated rocks of the St. Francois terrane in Missouri. The goal for this earlier work was to allow the comparison of Missouri iron-oxide deposits in context with other iron oxide-copper ± uranium (IOCG) types of mineral deposits observed globally. The raw geochemical analyses were released originally through the USGS National Geochemical Database (NGDB, http://mrdata.usgs.gov). The data presented herein offers all of the field notes, locations, rock descriptions, and geochemical analyses in a coherent package to facilitate new research efforts in IOCG deposit types. The data are provided in both Microsoft Excel (Version Office 2010) spreadsheet format (*.xlsx) and MS-DOS text formats (*.txt) for ease of use by numerous computer programs.

Missouri↗
USGS2011

A working environment for digital planetary data processing and mapping using ISIS and GRASS GIS

Since the beginning of planetary exploration, mapping has been fundamental to summarize observations returned by scientific missions. Sensor-based mapping has been used to highlight specific features from the planetary surfaces by means of processing. Interpretative mapping makes use of instrumental observations to produce thematic maps that summarize observations of actual data into a specific theme. Geologic maps, for example, are thematic interpretative maps that focus on the representation of materials and processes and their relative timing. The advancements in technology of the last 30 years have allowed us to develop specialized systems where the mapping process can be made entirely in the digital domain. The spread of networked computers on a global scale allowed the rapid propagation of software and digital data such that every researcher can now access digital mapping facilities on his desktop. The efforts to maintain planetary missions data accessible to the scientific community have led to the creation of standardized digital archives that facilitate the access to different datasets by software capable of processing these data from the raw level to the map projected one. Geographic Information Systems (GIS) have been developed to optimize the storage, the analysis, and the retrieval of spatially referenced Earth based environmental geodata; since the last decade these computer programs have become popular among the planetary science community, and recent mission data start to be distributed in formats compatible with these systems. Among all the systems developed for the analysis of planetary and spatially referenced data, we have created a working environment combining two software suites that have similar characteristics in their modular design, their development history, their policy of distribution and their support system. The first, the Integrated Software for Imagers and Spectrometers (ISIS) developed by the United States Geological Survey, represents the state of the art for processing planetary remote sensing data, from the raw unprocessed state to the map projected product. The second, the Geographic Resources Analysis Support System (GRASS) is a Geographic Information System developed by an international team of developers, and one of the core projects promoted by the Open Source Geospatial Foundation (OSGeo). We have worked on enabling the combined use of these software systems throughout the set-up of a common user interface, the unification of the cartographic reference system nomenclature and the minimization of data conversion. Both software packages are distributed with free open source licenses, as well as the source code, scripts and configuration files hereafter presented. In this paper we describe our work done to merge these working environments into a common one, where the user benefits from functionalities of both systems without the need to switch or transfer data from one software suite to the other one. Thereafter we provide an example of its usage in the handling of planetary data and the crafting of a digital geologic map. ?? 2010 Elsevier Ltd. All rights reserved.

Conference Paper↗
USGS1979

Pollen counts from core 7, Clear Lake, Lake County, California

The U. S. Geological Survey recovered eight sediment cores from beneath Clear Lake, Lake County, California, in 1973. The locations of the core sites are shown in fig. 1; lithologic descriptions of the cores, as well as radiographs, have been given by Sims and Rymer (1975a-g, 1976). A list of the procedures followed in sampling the cores and a list of the samples taken may be found in Beaver and others (1975); fish remains from two of the cores have been studied by Casteel and others (1975, 1977a,1977b). This report gives raw count data for 72 pollen samples from core 7, a 27.4-m long core from the southern or Highlands Arm of the lake (fig. 1). Pollen counts for core 4, a 115-m core from the main basin of the lake, are given in Adam (1979); that core spans the time interval between the end of the penultimate glacial period, about 130,000 years ago, and the present.

California↗
USGS1956

X-ray powder data for uranium and thorium minerals

The U.S. Geological Survey has in preparation a comprehensive volume on the mineralogy of uranium and thorium. This work has been done as part of a continuing systematic survey of data on uranium and thorium minerals on behalf of the Division of Raw Materials, U.S. Atomic Energy Commission. Pending publication of this volume and in response to a widespread demand among workers in uranium and thorium mineralogy, the X-ray powder diffraction data for the known minerals that contain uranium or thorium as an essential constituent are presented here. The coverage is complete except for a few minerals for which there are no reliable data owing to lack of authentic specimens. With the exception of that for ianthinite, the new data either originated in the Geological Survey or in the Mineralogical Laboratory of Harvard University. Data from the literature or other sources were cross-checked against the files of standard patterns of these laboratories; the sources are indicated in the references. Data not accompanied by a reference were obtained from films in the Harvard Standard File and cross-checked as to the identity of the film with the Geological Survey's file. Minor differences can be expected in the d-spacings reported for the same specimens by different investigators because of the manner of preparation of the mount, the conditions of X-ray irradiation, and the method of photography and measurement of the film or chart. The Harvard and Geological Survey data all were obtained from films taken in 114-mm diameter cameras, using either ethyl cellulose and toluene or collodion spindle mounts and Straumanis-type film mounting. Unless otherwise indicated all patterns were taken with copper radiation (Kα 1.5418 A.) and nickel filter and data are given in Angstrom units. The d-spacings are not corrected for film shrinkage. The correction ordinarily is small and in general is less than either the variation in spacing arising from differences in experimental technique of different investigators, including the varying absorption of samples of different thickness and concentration, or the variation attending slight changes in the chemical composition of the mineral. Some uranium minerals give poor diffraction patterns. The best results are generally obtained by using relatively small diameter spindles and long exposures, with a take-off angle from teh X-ray tube of about 4°. It is sometimes advantageous to shield the film from fluorescence in the visible region excited by X-ray irradiation. Copper radiation is preferable. The patterns of a few uranium minerals are greatly impaired by heavy grinding of the sample. Light crushing of the coarse sample after mixing with about one-third its volume of coarsely powdered low-absorption glass is helpful. Many uranium minerals, such as the members of the torbernite group, readily lose zeolithic water or transform to lower hydrates at or near ordinary conditions of temperature and humidity and care should be taken to control this in the manner of preservation and preparation of the sample.

Trace Elements Investigations↗
USGS1996

Plan for assessment of the occurrence, status, and distribution of volatile organic compounds in aquifers of the United States

The occurrence of volatile organic compounds (VOCs) in water is of national concern because of their relatively high aqueous solubility, mobility, and persistence, because many are known or suspected carcinogens, because of their widespread use, and because they have been found in drinking-water supplies. Because of this national concern, VOCs were selected for National investigation (hereafter termed "National Synthesis") by the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program in 1994. The broad goals of this National Synthesis are to: (1) describe current water- quality conditions with respect to VOCs; (2) define trends, or lack of trends, in VOCs in surface and ground water; and (3) identify, describe, and explain causal relations among the occurrence and distribution of VOCs in surface water and ground water, and natural and human factors. The National Synthesis of VOCs in ground water has three objectives: (1) to describe their occurrence, status, and distribution; (2) to determine relations among VOCs in shallow ground water and natural and human factors; and (3) to determine, compare, and contrast the occurrence, transformation, transport, and fate of selected VOCs in the hydrologic cycle for several regionally or nationally important aquifer systems. The description of VOC occurrence, status, and distribution in ground water focuses on major aquifers of the United States. Occurrence describes the presence or absence of VOCs, their frequency of occurrence, and their ranges of concentrations. Status compares the concentrations of VOCs detected in relation to water-quality regulations or advisories, such as Maximum Contaminant Levels, Proposed Maximum Contaminant Levels, Maximum Contaminant Level Goals, and Health Advisories. Distribution describes the variability of VOCs in ground water, areally and by depth. This report describes the study design for conducting such an assessment. The assessment focuses on aquifers, or parts of aquifers, that are currently used or have the potential to be used as sources of water supplies, using data collected as part of local, State, and Federal ground-water monitoring programs since 1985. Assessment by aquifer and comparison of results among aquifers will be completed for those aquifers for which adequate spatial or depth-related data are available. Assessment of VOCs in aquifers also will be completed at regional and national scales. A set of criteria for well-network design, well construction, sample-collection methods, and methods of laboratory analysis must be met before VOC data are used for assessment. An appropriate well-network design will provide a generally unbiased, random, equal-area distribution of sampling sites throughout the aquifer, or part of the aquifer, of interest. Well-construction information must be sufficient to ensure that the hydrogeologic unit (or units) represented by the water level measured and the hydrologic unit (or units) contributing water to the well are known. In addition, the well construction and pumping equipment in the well need to be of a type that are not likely to affect concentrations of VOCs in the water sample. VOC data will be considered suitable for use in the occurrence assessment if nationally accepted methods for collection and analysis were used and if the quantitation level for VOC analytes was less than about 5 micrograms per liter; laboratory analysis was done by a laboratory certified by the U.S. Environ- mental Protection Agency; and the sample was collected from untreated (raw) water at or near the well head before being held in a pressure tank or holding tank.

Open-File Report↗
USGS2007

Selenium concentrations in irrigation drain inflows to the Salton Sea, California, October 2006 and January 2007

This report presents raw data on selenium concentrations in samples of water, sediment, detritus, and selected food-chain matrices collected from selected agricultural drains in the southern portion of the Salton Sea during October 2006 and January 2007. Total selenium and selenium species were determined in water samples, whereas total selenium was determined in sediment, detritus, algae, plankton, midge larvae (Family Chironomidae), and two fish species (western mosquitofish, Gambusia affinis , and sailfin molly, Poecilia latipinna ).

Open-File Report↗
USGS2012

Archive of single beam and swath bathymetry data collected nearshore of the Gulf Islands National Seashore, Mississippi, from West Ship Island, Mississippi, to Dauphin Island, Alabama: Methods and data report for USGS Cruises 08CCT01 and 08CCT02, July 2008, and 09CCT03 and 09CCT04, June 2009

During the summers of 2008 and 2009 the USGS conducted bathymetric surveys from West Ship Island, Miss., to Dauphin Island, Ala., as part of the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazard Susceptibility project. The survey area extended from the shoreline out to approximately 2 kilometers and included the adjacent passes (fig. 1). The bathymetry was primarily used to create a topo-bathymetric map and provide a base-level assessment of the seafloor following the 2005 hurricane season. Additionally, these data will be used in conjunction with other geophysical data (chirp and side scan sonar) to construct a comprehensive geological framework of the Mississippi Barrier Island Complex. The culmination of the geophysical surveys will provide baseline bathymetry necessary for scientists to define and interpret seafloor habitat for this area and for scientists to predict future geomorpholocial changes of the islands with respect to climate change, storm impact, and sea-level rise. Furthermore, these data provide information for feasibility of barrier island restoration, particularly in Camille Cut, and for the preservation of historical Fort Massachusetts. For more information refer to http://ngom.usgs.gov/gomsc/mscip/index.html. Since bathymetric surveys have often been conducted for navigational purposes, soundings have traditionally been referenced to a water level datum using tide gages and tide models. Bathymetric measurements referenced to a Global Positioning System (GPS) is a more accurate way of representing water depth and has been implemented in the acquisition and processing procedures for these datasets. Previous single-beam bathymetric studies performed at the USGS Center for Coastal and Marine Science have successfully referenced bathymetric measurements to GPS (DeWitt and others, 2007; Hansen 2008 and 2009). The 2008-2009 bathymetry surveys were conducted as a test to (1) develop acquisition and processing technology utilizing both single beam and swath bathymetry survey methods together, (2) reference both types of measurements to GPS rather than water level, and (3) compare the differences between methods in acquisition and processing. Results of the survey are explained in greater detail within this report. To acquire suitable coverage of the study area in a limited time frame, the seafloor-elevation survey was conducted using three techniques: single-beam bathymetry, interferometric swath bathymetry, and a walking kinematic survey of the island shorelines. All three techniques utilized GPS measurements. Implementation of these techniques was executed concurrently yet independently aboard two research vessels: the RV Survey Cat , a 26-foot (ft) shallow-draft Glacier Bay Coastal Runner, and the 50-ft RV G.K. Gilbert . A portable push buggy with a rigid antenna mount served as the platform for the kinematic shoreline survey. Data from each survey technique was post-processed and edited independently with proper inclusion of the differentially processed external navigation files. The x,y,z components from each method were then combined and the two survey years (2008 and 2009) were merged into one dataset. The 2008 bathymetry data were processed at the USGS Center for Coastal and Marine Science in St. Petersburg, Fla., and the 2009 bathymetry data were processed at the USGS Coastal and Marine Science Center located in Woods Hole, Mass. This report serves as an archive of the processed single beam and interferometric swath bathymetry, outlines the methodology, and reports the results. Data products herein include gridded and interpolated digital depth surfaces, and x,y,z data products for both single beam and interferometric swath bathymetry. Additional files include trackline maps, navigation files, geographic information system (GIS) files, Field Activity Collection System (FACS) logs, and formal Federal Geographic Data Committee (FGDC) metadata. Scanned images of the handwritten FACS logs and digital FACS logs are also provided as PDF files. Refer to the Acronyms page for description of acronyms and abbreviations used in this report or hold the cursor over an acronym for a pop-up explanation. The USGS St. Petersburg Coastal and Marine Science Center assigns a unique identifier to each cruise or field activity. For example, 08CCT01 indicates that the data were collected in 2008 for the Coastal Change and Transport (CCT) study and the data were collected during the first (01) field activity for that project in that calendar year. Refer to http://walrus.wr.usgs.gov/infobank/programs/html/definition/activity.html for a detailed description of the method used to assign the field activity ID. See the digital FACS equipment log for details about the acquisition equipment used. Raw datasets are stored digitally at the USGS St. Petersburg Coastal and Marine Science Center and processed systematically using Novatel's GrafNav version 7.6, SANDS version 3.7, SEA SWATH plus version 3.06.04.03, CARIS HIPS AND SIPS version 3.6, and ESRI ArcGIS version 9.3.1. For more information on processing refer to the Equipment and Processing page. Chirp seismic data were also collected during these surveys and are archived separately.

Mississippi;Alabama↗
USGS2024

A Robot Operating System (ROS) package for mapping flow fields in rivers via Particle Image Velocimetry (PIV)

Non-contact, remote sensing approaches to measuring flow velocities in river channels are widely used, but typical workflows involve acquiring images in the field and then processing data later in the office. To reduce latency between acquisition and output, with the ultimate goal of enabling real-time image velocimetry, we developed a Robot Operating System (ROS) package for Particle Image Velocimetry (PIV) that can be deployed on an embedded computer aboard an uncrewed aircraft system (UAS). The ROSPIV package consists of a series of nodes that can be run in parallel and comprise an end-to-end PIV workflow. Software development involved converting MATLAB code to C++, organizing files within a catkin workspace, and building nodes using catkin_make . The codebase is available via a repository that includes a user’s guide and demo script. This paper describes the nodes in the ROSPIV package as well as functions for preparing inputs, facilitating code generation, and visualizing PIV output. To illustrate the application of the software, we present two examples, one based on a simulated image sequence and the other based on data acquired from a UAS. For the simulated data, the velocity field derived via the ROSPIV package closely matched the known flow field used to generate the image sequence. Using real data as input demonstrated the ability of the ROSPIV package to ingest and pre-process raw images. Our initial results suggest that the ROSPIV package could become a viable approach for mapping river surface velocities in real time.

Software X↗