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USGS2012

Total dissolved gas and water temperature in the lower Columbia River, Oregon and Washington, water year 2011: Quality-assurance data and comparison to water-quality standards

Significant Findings Air is entrained in water as it is flows through the spillways of dams, which causes an increase in the concentration of total dissolved gas in the water downstream from the dams. The elevated concentrations of total dissolved gas can adversely affect fish and other freshwater aquatic life. An analysis of total-dissolved-gas and water-temperature data collected at eight monitoring stations on the lower Columbia River in Oregon and Washington in 2011 indicated the following: During the spill season of April–August 2011, hourly values of total dissolved gas (TDG) were larger than 115-percent saturation for the forebay (John Day navigation lock, The Dalles forebay, and Bonneville forebay) and Camas stations. Hourly values of total dissolved gas were larger than 120-percent saturation for the tailwater stations (John Day Dam tailwater, The Dalles tailwater, Cascade Island, and Warrendale). During parts of August and September 2011, hourly water temperatures were greater than 20°C (degrees Celsius) at the eight stations on the lower Columbia River. According to the State of Oregon water-temperature standard, the 7-day average maximum temperature of the lower Columbia River should not exceed 20°C; Washington regulations state that the 1-day maximum should not exceed 20°C as a result of human activities. Of the 79 laboratory TDG checks that were performed on instruments after field deployment, all were within ± 0.5-percent saturation and only 2 checks were out of calibration by more than 2 mm of Hg. All but 4 of the 66 field checks of TDG sensors with a secondary standard were within ± 1.0-percent saturation after 3–4 weeks of deployment in the river. All 67 of the field checks of barometric pressure were within ±1 millimeter of mercury of a primary standard, and all 66 water-temperature field checks were within ±0.2°C of a secondary standard. For the eight monitoring stations in water year 2011, a total of 93.5 percent of the TDG data were received in real time and were within 1-percent saturation of the expected value on the basis of calibration data, replicate quality-control measurements in the river, and comparison to ambient river conditions at adjacent sites. Data received from the Cascade Island site were only 34.9% complete because the equipment was destroyed by high water. The other stations ranged from 99.6 to 100 percent complete.

Oregon, Washington↗

USGS2012

Magnetic map of the Irish Hills and surrounding areas, San Luis Obispo County, central California

A magnetic map of the Irish Hills and surrounding areas was created as part of a cooperative research and development agreement with the Pacific Gas and Electric Company and is intended to promote further understanding of the areal geology and structure by serving as a basis for geophysical interpretations and by supporting geological mapping, mineral and water resource investigations, and other topical studies. Local spatial variations in the Earth's magnetic field (evident as anomalies on magnetic maps) reflect the distribution of magnetic minerals, primarily magnetite, in the underlying rocks. In many cases the volume content of magnetic minerals can be related to rock type, and abrupt spatial changes in the amount of magnetic minerals can be related to either lithologic or structural boundaries. Magnetic susceptibility measurements from the area indicate that bodies of serpentinite and other mafic and ultramafic rocks tend to produce the most intense magnetic anomalies, but such generalizations must be applied with caution because some sedimentary units also can produce measurable magnetic anomalies. Remanent magnetization does not appear to be a significant source for magnetic anomalies because it is an order of magnitude less than the induced magnetization. The map is a mosaic of three separate surveys collected by (1) fixed-wing aircraft at a nominal height of 305 m, (2) by boat with the sensor at sea level, and (3) by helicopter. The helicopter survey was flown by New-Sense Geophysics in October 2009 along flight lines spaced 150-m apart and at a nominal terrain clearance of 50 to 100 m. Tie lines were flown 1,500-m apart. Data were adjusted for lag error and diurnal field variations. Further processing included microleveling using the tie lines and subtraction of the reference field defined by International Geomagnetic Reference Field (IGRF) 2005 extrapolated to August 1, 2008.

California↗

USGS2012

Summary of oceanographic and water-quality measurements near the Blackwater National Wildlife Refuge, Maryland, 2011

Suspended-sediment transport is a critical element governing the geomorphology of tidal marshes. Marshes rely on both organic material and inorganic sediment deposition to maintain their elevation relative to sea level. In wetlands near the Blackwater National Wildlife Refuge, Maryland, portions of the salt marsh have been subsiding relative to sea level since the early 20th century. Other portions of the marsh have been successful at maintaining elevation. The U.S. Geological Survey performed observational deployments to measure suspended-sediment concentration in the tidal channels in order to understand the magnitude of suspended-sediment concentrations, the sediment-transport mechanisms, and differences between two marsh areas, one that subsided and one that maintained elevation. We deployed optical turbidity sensors and acoustic velocity meters at multiple sites over two periods in 2011. This report presents the time-series of oceanographic data collected during those field studies, including velocity, depth, turbidity, salinity, water temperature, and pH.

Maryl↗

USGS2012

Mapping argillic and advanced argillic alteration in volcanic rocks, quartzites, and quartz arenites in the western Richfield 1° x 2 ° quadrangle, southwestern Utah, using ASTER satellite data

The Richfield quadrangle in southwestern Utah is known to contain a variety of porphyry Mo, skarn, polymetallic replacement and vein, alunite, and kaolin resources associated with 27-32 Ma calc-alkaline or 12-23 Ma bimodal volcano-plutonic centers in Neoproterozoic to Mesozoic carbonate and siliciclastic rocks. Four scenes of visible to shortwave-infrared image data acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor were analyzed to generate maps of exposed clay, sulfate, mica, and carbonate minerals, and ASTER thermal infrared data were analyzed to identify quartz and carbonate minerals. Argillic and advanced argillic alteration minerals including alunite, pyrophyllite, dickite, and kaolinite were identified in both undocumented (U) and known (K) areas, including in the southern Paradise Mtns. (U); in calc-alkaline volcanic rocks in the Wah Wah Mtns. between Broken Ridge and the NG area (U/K); at Wah Wah Summit in a small zone adjacent to 33.1 Ma diorite and marble (U); in fractures cutting quartzites surrounding the 20-22 Ma Pine Grove Mo deposit (U); in volcanic rocks in the Shauntie Hills (U/K); in quartzites in the west-central San Francisco Mtns. (U); in volcanic rocks in the Black Mtns. (K); and in mainly 12-13 Ma rhyolitic rocks along a 20 km E-W belt that includes the Bible Spring fault zone west of Broken Ridge, with several small centers in the Escalante Desert to the south (U/K). Argillized Navajo Sandstone with kaolinite and (or) dickite ± alunite was mapped adjacent to calc-alkaline intrusions in the Star Range (U). Intense quartz-sericite alteration (K) with local kaolinite was identified in andesite adjacent to calc-alkaline intrusions in the Beaver Lake Mountains. Mo-bearing phyllic alteration was identified in 22.2 Ma rhyolite plugs at the center of the NG alunite area. Limestones, dolomites, and marbles were differentiated, and quartz and sericite were identified in most unaltered quartzites. Halos of argillically-altered rock ≈12 km in diameter surround the Pine Grove deposit, the central rhyolites at NG, and the North Peaks just south of the Bible Spring fault zone. A southward shift from 22-23 Ma alunite at NG in the northeast to the 12-13 Ma alunite near Broken Ridge in the southwest mirrors a shift in the locus of bimodal magmatism and is similar to the southward shift of activity from the Antelope Range to Alunite Ridge (porphyry Mo potential) in the Marysvale volcanic field farther east. The poster provided in this report compares mineral maps generated from analysis of combined visible-near infrared (VNIR) and shortwave-infrared (SWIR) data and thermal infrared (TIR) ASTER data to a previously published regional geologic map. Such comparisons are used to identify and differentiate rock-forming and hydrothermal alteration-related minerals, which aids in lithologic mapping and alteration characterization over an 11,245 square kilometer area.

Utah↗

USGS2012

Shipboard surveys track magnetic sources in marine sediments--geophysical studies of the Stono and North Edisto Inlets near Charleston, South Carolina

Magnetic field data are traditionally used to analyze igneous and metamorphic rocks, but recent efforts have shown that magnetic sources within sediments may be detectable, suggesting new applications for high-resolution magnetic field surveys. Candidates for sedimentary sources include heavy mineral sand concentrations rich in magnetite or hematite, alteration-induced glauconite, or biogenic magnetite. Magnetic field surveys can be used to map the distributions of such sources with much denser and more widespread coverage than possible by sampling. These data can then provide constraints on the composition history of local sediments. Mapping such sediments requires the sensor to be relatively close to the source, and filtering approaches may be needed to distinguish signals from both system noise and deeper basement features. Marine geophysical surveys conducted in July, 2010, over the Stono and North Edisto River inlets and their riverine inputs south of Charleston, South Carolina, showed 10- to 40-m-wide, 1- to 6-nT magnetic anomalies associated with shallow, sand-covered seabed. These anomalies are distinct from system noise but are too narrow to represent basement features. The anomalies are present mostly in shallow areas where river sediments originating from upland areas enter the inlets. Surface grab samples from the North Edisto River contain trace amounts of heavy mineral sediments including hematite, maghemite, ilmenite, and magnetite, as well as garnet, epidote, zircon, and rutile. Previous stream sediment analyses show enhanced titanium over much of the Atlantic Coastal Plain. The combined data suggest that the anomalies are generated by titanium- and iron-rich heavy mineral sands ultimately originating from the Piedmont and Blue Ridge provinces, which are then reworked and concentrated by tidal currents.

South Carolina↗

USGS2012

Water-quality data from Upper Klamath and Agency Lakes, Oregon, 2009-10

The U.S. Geological Survey Upper Klamath Lake water-quality monitoring program collected data from multiparameter continuous water-quality monitors, weekly water-quality samples, and meteorological stations during 2009 and 2010 from May through November each year. The results of these measurements and sample analyses, as well as quality-control data for the water-quality samples, are presented in this report for 14 sites on Upper Klamath Lake and 2 sites on Agency Lake. These 2 years of data demonstrate a contrast in the seasonal bloom of the dominant cyanobacterium, Aphanizomenon flos-aquae , that can be related to differences in the measured water quality and meteorological variables. Some of the significant findings from 2009 and 2010 are listed below. * Both 2009 and 2010 were characterized by two cyanobacteria blooms, but the blooms differed in timing and intensity. The first bloom in 2009 peaked in late June and at higher chlorophyll a concentrations at most sites than the first bloom in 2010, which peaked in mid-July. A major decline in the first 2009 bloom occurred in late July and was followed by a second bloom that peaked at most sites in mid-August and persisted through September. The decline of the weaker first bloom in 2010 occurred in early August and was followed by a more substantial second bloom that peaked between late August and early September at most sites. * Dissolved oxygen minima associated with bloom declines occurred approximately 2 weeks earlier in 2009 (mid-July) than in 2010 (early August). pH maxima associated with rapid bloom growth occurred in late June and again in mid-August in 2009 and in mid-July and late August in 2010. * In both years, the maxima for total phosphorus and total nitrogen concentrations coincided with the chlorophyll a maximum. The maxima for dissolved nutrient concentrations (orthophosphate, ammonia, and nitrite plus nitrate) coincided with the declines of the first blooms. * Total particulate carbon, total particulate nitrogen, and total particulate phosphorus concentrations were measured in 2009 only. The ratios of carbon to phosphorus and nitrogen to phosphorus in particulates were the highest of the entire season during the rapid growth phase of the first bloom and were the lowest of the season during the decline of the first bloom. These ratios increased with the onset of the second bloom in that year, but to a lesser degree. * Meteorological data show that 2009 was warmer (particularly in June and July), less windy, and more humid early in the season than 2010. The difference in water temperatures reflected the difference in air temperatures in that the lakes were warmer in 2009 than in 2010 starting in early May, when the sensors were deployed, through most of June. Water temperature peaked at a higher value in 2009, and there were more clear days in June 2009 than in June 2010.

Oregon↗

USGS2013

Carolinas coastal change processes project data report for nearshore observations at Cape Hatteras, North Carolina

An oceanographic field study conducted in February 2010 investigated processes that control nearshore flow and sediment transport dynamics at Cape Hatteras, North Carolina. This report describes the project background, field program, instrumentation setup, and locations of the sensor deployments. The data collected, and supporting meteorological and streamflow observations, are presented as time-series plots for data visualization. Additionally, the data are available as part of this report.

North Carolina↗

USGS2013

Total dissolved gas and water temperature in the lower Columbia River, Oregon and Washington, water year 2012: Quality-assurance data and comparison to water-quality standards

Significant Findings Air is entrained in water as it is flows through the spillways of dams, which causes an increase in the concentration of total dissolved gas in the water downstream from the dams. The elevated concentrations of total dissolved gas can adversely affect fish and other freshwater aquatic life. An analysis of total-dissolved-gas and water-temperature data collected at eight monitoring stations on the lower Columbia River in Oregon and Washington in 2012 indicated the following: During parts of the spill season of April–August 2012, hourly values of total dissolved gas (TDG) were larger than 115-percent saturation for the forebay stations (John Day navigation lock, The Dalles forebay, and Bonneville forebay) and the Camas station. Hourly values of total dissolved gas were larger than 120-percent saturation for the tailwater stations (John Day Dam tailwater, The Dalles tailwater, Cascade Island, and Warrendale). During parts of August and September 2012, hourly water temperatures were greater than 20°C (degrees Celsius) at the eight stations on the lower Columbia River. According to the State of Oregon water-temperature standard, the 7-day average of the daily maximum temperature of the lower Columbia River should not exceed 20°C; Washington regulations state that the 1-day maximum should not exceed 20°C as a result of human activities. Of the 98 laboratory TDG checks that were performed on instruments after field deployment, all were within ± 0.7-percent saturation. All but 1 of the 83 field checks of TDG sensors with a secondary standard were within ± 1.0-percent saturation after 3–4 weeks of deployment in the river. All 88 of the field checks of barometric pressure were within ±1 millimeter of mercury of a primary standard, and all 85 water-temperature field checks were within ±0.2°C of a secondary standard. For the eight monitoring stations in water year 2012, a total of 97.0 percent of the TDG data were received in real time and were within 1-percent saturation of the expected value on the ba-sis of calibration data, replicate quality-control measurements in the river, and comparison to ambient river conditions at adjacent sites. Data received from the Cascade Island site were only 77.8 percent complete because the equipment was destroyed by high water. The other stations ranged from 98.9 to 100.0 percent complete.

Oregon, Washington↗

USGS2013

An automated digital imaging system for environmental monitoring applications

Recent improvements in the affordability and availability of high-resolution digital cameras, data loggers, embedded computers, and radio/cellular modems have advanced the development of sophisticated automated systems for remote imaging. Researchers have successfully placed and operated automated digital cameras in remote locations and in extremes of temperature and humidity, ranging from the islands of the South Pacific to the Mojave Desert and the Grand Canyon. With the integration of environmental sensors, these automated systems are able to respond to local conditions and modify their imaging regimes as needed. In this report we describe in detail the design of one type of automated imaging system developed by our group. It is easily replicated, low-cost, highly robust, and is a stand-alone automated camera designed to be placed in remote locations, without wireless connectivity.

Open-File Report↗

USGS2013

Model documentation for relations between continuous real-time and discrete water-quality constituents in the North Fork Ninnescah River upstream from Cheney Reservoir, south-central Kansas, 1999--2009

Cheney Reservoir in south-central Kansas is one of the primary sources of water for the city of Wichita. The North Fork Ninnescah River is the largest contributing tributary to Cheney Reservoir. The U.S. Geological Survey has operated a continuous real-time water-quality monitoring station since 1998 on the North Fork Ninnescah River. Continuously measured water-quality physical properties include streamflow, specific conductance, pH, water temperature, dissolved oxygen, and turbidity. Discrete water-quality samples were collected during 1999 through 2009 and analyzed for sediment, nutrients, bacteria, and other water-quality constituents. Regression models were developed to establish relations between discretely sampled constituent concentrations and continuously measured physical properties to estimate concentrations of those constituents of interest that are not easily measured in real time because of limitations in sensor technology and fiscal constraints. Regression models were published in 2006 that were based on a different dataset collected during 1997 through 2003. This report updates those models using discrete and continuous data collected during January 1999 through December 2009. Models also were developed for five new constituents, including additional nutrient species and indicator bacteria. The water-quality information in this report is important to the city of Wichita because it allows the concentrations of many potential pollutants of interest, including nutrients and sediment, to be estimated in real time and characterized over conditions and time scales that would not be possible otherwise.

Kansas↗

USGS2013

U.S. Geological Survey science for the Wyoming Landscape Conservation Initiative: 2011 annual report

This is the fourth report produced by the U.S. Geological Survey (USGS) for the Wyoming Landscape Conservation Initiative (WLCI) to detail annual work activities. In FY2011, there were 37 ongoing, completed, or new projects conducted under the five major multi-disciplinary science and technical-assistance activities: (1) Baseline Synthesis, (2) Targeted Monitoring and Research, (3) Data and Information Management, (4) Integration and Coordination, and (5) Decisionmaking and Evaluation. The four new work activities were (1) development of the Western Energy Citation Clearinghouse, a Web-based energy-resource database of references for literature and on-line resources focused on energy development and its effects on natural resources; (2) a study to support the Sublette County Conservation District in ascertaining potential water-quality impacts to the New Fork River from energy development in the Pinedale Anticline Project Area; (3) a study to test the efficacy of blending high-frequency temporal data provided by Moderate Resolution Imaging Spectroradiometer (MODIS) sensors and high-resolution Landsat data for providing the fine-resolution data required to evaluate habitat responses to management activities at the landscape level; and (4) a study to examine the seasonal water chemistry of Muddy Creek, including documenting salinity patterns and providing a baseline for assessing potential effects of energy and other development on water quality in the Muddy Creek watershed. Two work activities were completed in FY2011: (1) the assessment of rancher perceptions of energy development in Southwest Wyoming and (2) mapping aspen stands and conifer encroachment using classification and regression tree (CART) analysis for effectiveness monitoring. The USGS continued to compile data, develop geospatial products, and upgrade Web-based products in support of both individual and overall WLCI efforts, including (1) ranking and prioritizing proposed conservation projects, (2) developing the WLCI integrated assessment, (3) developing the WLCI 5-year Conservation Action Plan, and (4) continuing to upgrade the content and improve the functionality of the WLCI Web site. For the WLCI FY2012 annual report, a decision was made to greatly reduce the overall length of the annual report, which will be accomplished by simplifying the report format and focusing on the take-home messages of each work activity for WLCI partners.

Wyoming↗

USGS2013

Monitoring storm tide and flooding from Hurricane Sandy along the Atlantic coast of the United States, October 2012

The U.S. Geological Survey (USGS) deployed a temporary monitoring network of water-level and barometric pressure sensors at 224 locations along the Atlantic coast from Virginia to Maine to continuously record the timing, areal extent, and magnitude of hurricane storm tide and coastal flooding generated by Hurricane Sandy. These records were greatly supplemented by an extensive post-flood high-water mark (HWM) flagging and surveying campaign from November to December 2012 involving more than 950 HWMs. Both efforts were undertaken as part of a coordinated federal emergency response as outlined by the Stafford Act under a directed mission assignment by the Federal Emergency Management Agency (FEMA).

Connecticut, Delaware, Maine, Maryland, Massachuse↗

USGS2013

Multiscale sagebrush rangeland habitat modeling in the Gunnison Basin of Colorado

North American sagebrush-steppe ecosystems have decreased by about 50 percent since European settlement. As a result, sagebrush-steppe dependent species, such as the Gunnison sage-grouse, have experienced drastic range contractions and population declines. Coordinated ecosystem-wide research, integrated with monitoring and management activities, is needed to help maintain existing sagebrush habitats; however, products that accurately model and map sagebrush habitats in detail over the Gunnison Basin in Colorado are still unavailable. The goal of this project is to provide a rigorous large-area sagebrush habitat classification and inventory with statistically validated products and estimates of precision across the Gunnison Basin. This research employs a combination of methods, including (1) modeling sagebrush rangeland as a series of independent objective components that can be combined and customized by any user at multiple spatial scales; (2) collecting ground measured plot data on 2.4-meter QuickBird satellite imagery in the same season the imagery is acquired; (3) modeling of ground measured data on 2.4-meter imagery to maximize subsequent extrapolation; (4) acquiring multiple seasons (spring, summer, and fall) of Landsat Thematic Mapper imagery (30-meter) for optimal modeling; (5) using regression tree classification technology that optimizes data mining of multiple image dates, ratios, and bands with ancillary data to extrapolate ground training data to coarser resolution Landsat Thematic Mapper; and 6) employing accuracy assessment of model predictions to enable users to understand their dependencies. Results include the prediction of four primary components including percent bare ground, percent herbaceous, percent shrub, and percent litter, and four secondary components including percent sagebrush (Artemisia spp.), percent big sagebrush (Artemisia tridentata), percent Wyoming sagebrush (Artemisia tridentata wyomingensis), and shrub height (centimeters). Results were validated with an independent accuracy assessment, with root mean square error values ranging from 3.5 (percent big sagebrush) to 10.8 (percent bare ground) at the QuickBird scale, and from 4.5 (percent Wyoming sagebrush) to 12.4 (percent herbaceous) at the full Landsat scale. These results offer significant improvement in sagebrush ecosystem quantification across the Gunnison Basin, and also provide maximum flexibility to users to employ for a wide variety of applications. Further refinement of these remote sensing component predictions in the future will be most likely achieved by focusing on more extensive ground plot sampling, employing new high and moderate-resolution satellite sensors that offer additional spectral bands for vegetation discrimination, and capturing more dates of satellite imagery to better represent phenological variation.

Colorado↗

USGS2013

Tidal flow dynamics and background fluorescence of the Atlantic Intracoastal Waterway in the vicinity of Sullivan’s Island and the Isle of Palms, South Carolina, 2011-12

To effectively plan site-specific studies to understand the connection between wastewater effluent and shellfish beds, data are needed concerning flow dynamics and background fluorescence in the Atlantic Intracoastal Waterway near the effluent outfalls on Sullivan’s Island and the Isle of Palms. Tidal flows were computed by the U.S. Geological Survey for three stations and longitudinal water-quality profiles were collected at high and low tide. Flows for the three U.S. Geological Survey stations, the Atlantic Intracoastal Waterway by the Isle of Palms Marina, the Atlantic Intracoastal Waterway by the Ben M. Sawyer Memorial Bridge at Sullivan’s Island, and Breach Inlet, were computed for the 53-day period from December 4, 2011, to January 26, 2012. The largest flows occurred at Breach Inlet and ranged from -58,600 cubic feet per second (ft 3 /s) toward the Atlantic Intracoastal Waterway to 63,300 ft 3 /s toward the Atlantic Ocean. Of the two stations on the Atlantic Intracoastal Waterway, the Sullivan’s Island station had the larger flows and ranged from -6,360 ft 3 /s to the southwest (toward Charleston Harbor) to 8,930 ft 3 /s to the northeast. Computed tidal flow at the Isle of Palms station ranged from -3,460 ft 3 /s toward the southwest to 6,410 ft 3 /s toward the northeast. The synoptic water-quality study showed that the stations were well mixed vertically and horizontally. All fluorescence measurements (recorded as rhodamine concentration) were below the accuracy of the sensor and the background fluorescence would not likely interfere with a dye-tracer study.

South Carolina↗

USGS2013

Laboratory evaluation of the Level TROLL 100 manufactured by In-Situ Inc.: results of pressure and temperature tests

The Level TROLL 100 manufactured by In-Situ Inc. was evaluated by the U.S. Geological Survey (USGS) Hydrologic Instrumentation Facility (HIF) for conformance to the manufacturer’s accuracy specifications for measuring pressure throughout the device’s operating temperature range. The Level TROLL 100 is a submersible, sealed, water-level sensing device with an operating pressure range equivalent to 0 to 30 feet of water over a temperature range of −20 to 50 degrees Celsius (°C). The device met the manufacturer’s stated accuracy specifications for pressure within its temperature-compensated operating range of 0 to 50 °C. The device’s accuracy specifications did not meet established USGS requirements for primary water-stage sensors used in the operation of streamgages, but the Level TROLL 100 may be suitable for other hydrologic data-collection applications. As a note, the Level TROLL 100 is not designed to meet USGS accuracy requirements. Manufacturer accuracy specifications were evaluated, and the procedures followed and the results obtained are described in this report. USGS accuracy requirements are routinely examined and reported when instruments are evaluated at the HIF.

Open-File Report↗

USGS2015

Landsat maps (phase V, deliverable 60), ASTER maps (phase V, deliverable 62), ASTER_DEM maps (phase V, deliverable 63), and spectral remote sensing in support of PRISM-II mineral resource assessment project, Islamic Republic of Mauritania (phase V, deliverables 61 and 64)

Multispectral satellite data acquired by the Landsat 5 Thematic Mapper (TM), Landsat 7 Enhanced Thematic Mapper Plus (ETM+), and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensors were processed and interpreted in support of the PRISM-II project (Second Projet de Renforcement Institutionnel du Secteur Minier de la Republique Islamique de Mauritanie). This report and accompanying maps constitute project deliverables 60–64. All digital data for use in Geographic Information System (GIS) and image processing software will be included in the GIS deliverable 92. Image maps in PDF format of the processed Landsat and ASTER scenes are referenced in the appendixes. Samples of rock, alluvium, colluvium, and (or) eolian sediments were collected at 41 locations during the 2007 field campaign. A point shapefile (“IRM07_sample_gps_points.shp”) containing these locations will be included in GIS deliverable 92. Most of the samples were characterized in the laboratory using a full-range ASD™ (Analytical Spectral Devices) FieldSpec II spectrometer. The image products derived from Landsat TM and ASTER data enable the delineation of mineral groups across wide areas based on color response. Guides are provided that allow users to interpret these colors as to mineral group occurrence over lithologic units and known deposits. This information can be extrapolated to other geologically permissive tracts for various deposit types in the search for similar mineralogic responses that may be indicative of concealed deposits.

Open-File Report↗

USGS2014

Measurements of slope currents and internal tides on the Continental Shelf and slope off Newport Beach, California

An array of seven moorings housing current meters and oceanographic sensors was deployed for 6 months at 5 sites on the Continental Shelf and slope off Newport Beach, California, from July 2011 to January 2012. Full water-column profiles of currents were acquired at all five sites, and a profile of water-column temperature was also acquired at two of the five sites for the duration of the deployment. In conjunction with this deployment, the Orange County Sanitation District deployed four bottom platforms with current meters on the San Pedro Shelf, and these meters provided water-column profiles of currents. The data from this program will provide the basis for an investigation of the interaction between the deep water flow over the slope and the internal tide on the Continental Shelf.

California↗

USGS2014

A brief test of the Hewlett-Packard MEMS seismic accelerometer

Testing was performed on a prototype of Hewlett-Packard (HP) Micro-Electro-Mechanical Systems (MEMS) seismic accelerometer at the U.S. Geological Survey’s Albuquerque Seismological Laboratory. This prototype was built using discrete electronic components. The self-noise level was measured during low seismic background conditions and found to be 9.8 ng/√Hz at periods below 0.2 s (frequencies above 5 Hz). The six-second microseism noise was also discernible. The HP MEMS accelerometer was compared to a Geotech Model GS-13 reference seismometer during seismic noise and signal levels well above the self-noise of the accelerometer. Matching power spectral densities (corrected for accelerometer and seismometer responses to represent true ground motion) indicated that the HP MEMS accelerometer has a flat (constant) response to acceleration from 0.0125 Hz to at least 62.5 Hz. Tilt calibrations of the HP MEMS accelerometer verified that the flat response to acceleration extends to 0 Hz. Future development of the HP MEMS accelerometer includes replacing the discreet electronic boards with a low power application-specific integrated circuit (ASIC) and increasing the dynamic range of the sensor to detect strong motion signals above one gravitational acceleration, while maintaining the self-noise observed during these tests.

Open-File Report↗