USGS Science⌕ Search

SEARCH · USGS Science

Results for “Completion Report”

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

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,387 records · Page 77Linked to original sources
USGS2004

Modeling a three-dimensional river plume over continental shelf using a 3D unstructured grid model

River derived fresh water discharging into an adjacent continental shelf forms a trapped river plume that propagates in a narrow region along the coast. These river plumes are real and they have been observed in the field. Many previous investigations have reported some aspects of the river plume properties, which are sensitive to stratification, Coriolis acceleration, winds (upwelling or downwelling), coastal currents, and river discharge. Numerical modeling of the dynamics of river plumes is very challenging, because the complete problem involves a wide range of vertical and horizontal scales. Proper simulations of river plume dynamics cannot be achieved without a realistic representation of the flow and salinity structure near the river mouth that controls the initial formation and propagation of the plume in the coastal ocean. In this study, an unstructured grid model was used for simulations of river plume dynamics allowing fine grid resolution in the river and in regions near the coast with a coarse grid in the far field of the river plume in the coastal ocean, in the vertical, fine fixed levels were used near the free surface, and coarse vertical levels were used over the continental shelf. The simulations have demonstrated the uniquely important role played by Coriolis acceleration. Without Coriolis acceleration, no trapped river plume can be formed no matter how favorable the ambient conditions might be. The simulation results show properties of the river plume and the characteristics of flow and salinity within the estuary; they are completely consistent with the physics of estuaries and coastal oceans.

Conference Paper↗
USGS2025

System characterization report on the Environmental Mapping and Analysis Program (EnMAP)

This report addresses system characterization of the Environmental Mapping and Analysis Program hyperspectral sensor by the DLR (German Aerospace Center, ground segment project management), GFZ (Deutsches Geoforschungszentrum, science lead) and is part of a series of system characterization reports produced and delivered by the U.S. Geological Survey Earth Resources Observation and Science Cal/Val Center of Excellence. These reports present and detail the methodology and procedures for characterization; present technical and operational information about the EnMAP hyperspectral sensor; and provide a summary of test measurements, data retention practices, data analysis results, and conclusions. The Earth Resources Observation and Science Cal/Val Center of Excellence system characterization team completed data analyses to characterize the geometric (interior and exterior), and radiometric performances of the EnMAP hyperspectral sensor. Results of these analyses indicate that the Environmental Mapping and Analysis Program has a band-to-band geometric performance in the range of −0.135 to 0.15 pixel, geometric performance relative to the Operational Land Imager in the range of −27.716 meters (−0.92 pixel) to 32.892 meters (1.09 pixels) offset in comparison to Landsat 8 Operational Land Imager, offset of a radiometric comparison in the range of −0.012 to 0.020, slope of a radiometric comparison in the range of 0.947 to 1.031.

Open-File Report↗
USGS2009

Trends in Surface-Water Quality at Selected Ambient-Monitoring Network Stations in Kentucky, 1979-2004

Increasingly complex water-management decisions require water-quality monitoring programs that provide data for multiple purposes, including trend analyses, to detect improvement or deterioration in water quality with time. Understanding surface-water-quality trends assists resource managers in identifying emerging water-quality concerns, planning remediation efforts, and evaluating the effectiveness of the remediation. This report presents the results of a study conducted by the U.S. Geological Survey, in cooperation with the Kentucky Energy and Environment Cabinet-Kentucky Division of Water, to analyze and summarize long-term water-quality trends of selected properties and water-quality constituents in selected streams in Kentucky's ambient stream water-quality monitoring network. Trends in surface-water quality for 15 properties and water-quality constituents were analyzed at 37 stations with drainage basins ranging in size from 62 to 6,431 square miles. Analyses of selected physical properties (temperature, specific conductance, pH, dissolved oxygen, hardness, and suspended solids), for major ions (chloride and sulfate), for selected metals (iron and manganese), for nutrients (total phosphorus, total nitrogen, total Kjeldahl nitrogen, nitrite plus nitrate), and for fecal coliform were compiled from the Commonwealth's ambient water-quality monitoring network. Trend analyses were completed using the S-Plus statistical software program S-Estimate Trend (S-ESTREND), which detects trends in water-quality data. The trend-detection techniques supplied by this software include the Seasonal Kendall nonparametric methods for use with uncensored data or data censored with only one reporting limit and the Tobit-regression parametric method for use with data censored with multiple reporting limits. One of these tests was selected for each property and water-quality constituent and applied to all station records so that results of the trend procedure could be compared among stations. Flow-adjustment procedures were used with these techniques at all stations to remove the effects of streamflow on water-quality variability. Flow adjustments were used for all constituents, except temperature. A decreasing trend indicates a decrease in concentration of a particular constituent; whereas, an increasing trend indicates an increase in concentration and potential degradation in water quality. Trend results varied statewide by station and by physical property and water-quality constituent. The results for all stations and all physical properties and water-quality constituents examined had at least one statistically significant (p-value <0.05) increasing or decreasing trend during the specified period of record. Water temperature and concentrations of dissolved oxygen had no significant decreasing trends at any station. Water temperature had one significant increasing trend at the South Fork Cumberland River near Blue Heron station. Specific conductance and concentrations of hardness had one significant decreasing trend at the South Fork Cumberland River near Blue Heron station. pH also had a significant decreasing trend at the Mud River near Gus station. Concentrations of total suspended solids had 1 increasing trend at the Kentucky River at High Bridge station and 10 decreasing trends with 5 of those stations located in the Cumberland River Basin. Major ions analyzed for trends included chloride and sulfate. Concentrations of chloride at the 37 stations had increasing trends at 15 stations, decreasing trends at 3 stations, and no significant trend in concentration over time at 19 stations. Most of the increasing trends in concentrations of chloride are located in the northern part of Kentucky, possibly indicating an increase in the use of road salts for road deicing and (or) the result of resource extraction (oil, gas, and coal). Increasing trends of sulfate concentrations were detected at seven stations, all located in the Appalachian

Scientific Investigations Report↗
USGS1984

Vertical crustal movements in Southern California, 1974 to 1978

An extensive resurvey of most of the first-order leveling network in southern California, known as the Southern California Releveling Program (SCRP), was carried out during the first 5 months of 1978. The primary scientific purpose of these measurements was to rapidly update the vertical control record throughout a recently uplifted region of southern California in order to more thoroughly document the vertical component of tectonic movement and to provide a reliable base for comparison with future levelings. Analyses of historic first-order leveling results have clearly demonstrated that a broad crustal upwarping, largely contained within a region consisting of the Transverse Ranges province and an area along the intervening section of the San Andreas fault system, had developed between about 1959 and 1974. Unfortunately, there is strong evidence that parts of the 1978 SCRP data are contaminated by the effects of intrasurvey tectonic deformation, limited surficial failures, and, less certainly, magnetically induced systematic error associated with the use of automatic levels. However, any distortions in leveling results caused by these or other factors are not so serious as to render the SCRP data useless. In fact, the bulk of these data can be accepted at face value, and most of the remaining data can be incorporated with some caution to augment the more reliable parts of the network. The evaluation of the 1978 leveling is based on a combination of circuit-misclosures, local timing of the field observations, analysis of profiles of apparent height changes derived from comparisons with previous levelings, and an analysis of the position and orientation of the various routes in relation to the regional structural grain and the gradients of differential vertical motion established by previous investigations. Comparisons of the 1978 SCRP results with the latest of the previous surveys along each route retained in the analysis show that all but about one-third of the uplift established by leveling data from 1959 to the combined 1974/76 survey period had relaxed by early 1978 through tectonic subsidence. Subsequent limited relevelings along several of the 1978 routes show that rapid tectonic subsidence probably continued through at least early 1979. Despite the pronounced down-to-the-northeast (northeastward) tilt that developed between 1976 and early 1978, the overall shape of the uplift was well preserved. Results of repeated trilateration surveys since 1971 demonstrate that a remarkably uniform and nearly monotonic negative dilatational strain-change trend reversed abruptly between 1977 and 1979. The change from tectonic up to tectonic subsidence is associated with this reversal in horizontal strain accumulation. The reversal in strain trend was expressed as a cessation of the essentially uniaxial north-south contraction, which had been accumulating at about 2? 10 -7/yr (or 0.2 ?strain/yr), accompanied by onset of uniaxial east-west extension at about 5 ? 10 -7/yr (or 0.5 ?strain/yr). Minor earthquakes and occasional swarms of moderate earthquakes were particularly abundant during 1978 and 1979 in conspicuously mobile regions such as the eastern Transverse Ranges and the Salton Trough, areas respectively characterized by nearly complete collapse of the previous maximum uplift and by a dramatic enhancement of the previously identified tectonic subsidence.

Circular↗
USGS1975

Water resources of the Zumbro River watershed, southeastern Minnesota

The Zumbro River drains 1,428 square miles and falls from about 1,300 feet altitude in its headwaters to 665 feet at its mouth. The remaining 248 square miles included in the watershed is drained by small creeks flowing directly into the Mississippi River. Distribution of water use is about as follows: domestic, 50 percent; farm (for irrigation and livestock), 18 percent; and industrial, 32 percent. Total usage, in water-budget terms, is 0.24 inch over the entire watershed, or less than 1 percent of inflow (average annual precipitation). Total quantity of water, thus, is of lesser concern than local availability and quality of water. The dominant ions (calcium, magnesium, and bicarbonate) and dissolved solids are reduced by dilution during periods of high water discharge in the Zumbro River at Zumbro Falls. Similarly, in the South Fork Zumbro River near Rochester, dominant ions, dissolved solids, and those ions that are increased by waste disposal (sodium, chloride, and nitrates) are all reduced by dilution at high water discharge. For the Zumbro River the smallest monthly range and the most uniform daily mean discharge usually occurs in January, whereas the greatest range usually occurs in March. The lowest flows usually occur in the winter and the highest during the spring ice breakup. The lowest observed flow, 47 cfs, occurred on February 18, 1961 and the highest, 23,600 cfs, occurred on March 29, 1962. Seventeen of 22 municipalities obtain at least part of their water supply from the Prairie du Chien-Jordan aquifer. Although only one town uses the Galena aquifer, a large number of private domestic wells are completed in it in the western part of the watershed. (Woodard-USGS)

Minnesota↗
USGS2013

National assessment of hurricane-induced coastal erosion hazards: Southeast Atlantic Coast

Beaches serve as a natural barrier between the ocean and inland communities, ecosystems, and natural resources. However, these dynamic environments move and change in response to winds, waves, and currents. During extreme storms, changes to beaches can be large, and the results are sometimes catastrophic. Lives may be lost, communities destroyed, and millions of dollars spent on rebuilding. During storms, large waves may erode beaches, and high storm surge shifts the erosive force of the waves higher on the beach. In some cases, the combined effects of waves and surge may cause overwash or flooding. Building and infrastructure on or near a dune can be undermined during wave attack and subsequent erosion. During Hurricane Ivan in 2004, a five-story condominium in Orange Beach, Alabama, collapsed after the sand dune supporting the foundation eroded. The September 1999 landfall of Hurricane Dennis caused erosion and undermining that destroyed roads, foundations, and septic systems. Waves overtopping a dune can transport sand inland, covering roads and blocking evacuation routes or emergency relief. If storm surge inundates barrier island dunes, currents flowing across the island can create a breach, or new inlet, completely severing evacuation routes. Waves and surge during the 2003 landfall of Hurricane Isabel left a 200-meter (m) wide breach that cut the only road to and from the village of Hatteras, N.C. Extreme coastal changes caused by hurricanes may increase the vulnerability of communities both during a storm and to future storms. For example, when sand dunes on a barrier island are eroded substantially, inland structures are exposed to storm surge and waves. Absent or low dunes also allow water to flow inland across the island, potentially increasing storm surge in the back bay, on the soundside of the barrier, and on the mainland. During Hurricane Isabel the protective sand dunes near the breach were completely eroded, increasing vulnerability to future storms.

North Carolina;South Carolina;Georgia;Florida↗
USGS2014

Total dissolved gas and water temperature in the lower Columbia River, Oregon and Washington, water year 2013: quality-assurance data and comparison to water-quality standards

Significant Findings An analysis of total-dissolved-gas (TDG) and water-temperature data collected at eight fixed monitoring stations on the lower Columbia River in Oregon and Washington in water year 2013 indicated the following: During the spill season of April&ndash;August 2013, the averages of the 12 highest hourly TDG values in a day were periodically greater than 115-percent saturation for the forebay stations (John Day navigation lock, The Dalles forebay, and Bonneville forebay) and the Camas station. The 12 highest average daily values of TDG were also periodically greater than 120-percent saturation at Cascade Island. TDG values at the other tailwater stations (John Day Dam tailwater, The Dalles tailwater, and Warrendale) did not exceed 120-percent saturation. During parts of July, August, and September 2013, hourly water temperatures were greater than 20 degrees Celsius at all eight monitoring stations on the lower Columbia River. All of the 98 TDG sensor laboratory checks that were performed after field deployment were within &plusmn;0.5-percent saturation of a primary standard. After 3&ndash;4 weeks of deployment in the river, all but 1 of 85 TDG sensor field checks were within &plusmn;1.0-percent saturation of a secondary standard. All but 1 of 87 barometric pressure field checks were within &plusmn;1 millimeter of mercury of a primary standard, and all 86 water-temperature field checks were within &plusmn;0.2 degrees Celsius of a secondary standard. For the eight monitoring stations, a total of 99.2 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, and comparison to river conditions at adjacent sites. Data completeness for the monitoring stations ranged from 97.7 to 100 percent. All quality-assurance and data completeness values exceed the criteria established by the U.S. Army Corps of Engineers TDG monitoring plan.

Oregon, Washington↗
USGS2008

Potential for bed-material entrainment in selected streams of the Edwards Plateau - Edwards, Kimble, and Real Counties, Texas, and vicinity

The Texas Department of Transportation spends considerable money for maintenance and replacement of low-water crossings of streams in the Edwards Plateau in Central Texas as a result of damages caused in part by the transport of cobble- and gravel-sized bed material. An investigation of the problem at low-water crossings was made by the U.S. Geological Survey in cooperation with the Texas Department of Transportation, and in collaboration with Texas Tech University, Lamar University, and the University of Houston. The bed-material entrainment problem for low-water crossings occurs at two spatial scales - watershed scale and channel-reach scale. First, the relative abundance and activity of cobble- and gravel-sized bed material along a given channel reach becomes greater with increasingly steeper watershed slopes. Second, the stresses required to mobilize bed material at a location can be attributed to reach-scale hydraulic factors, including channel geometry and particle size. The frequency of entrainment generally increases with downstream distance, as a result of decreasing particle size and increased flood magnitudes. An average of 1 year occurs between flows that initially entrain bed material as large as the median particle size, and an average of 1.5 years occurs between flows that completely entrain bed material as large as the median particle size. The Froude numbers associated with initial and complete entrainment of bed material up to the median particle size approximately are 0.40 and 0.45, respectively.

Scientific Investigations Report↗
USGS2011

Monitoring to assess progress toward meeting the Assabet River, Massachusetts, phosphorus total maximum daily load - Aquatic macrophyte biomass and sediment-phosphorus flux

In 2004, the Total Maximum Daily Load (TMDL) for Total Phosphorus in the Assabet River, Massachusetts, was approved by the U.S. Environmental Protection Agency. The goal of the TMDL was to decrease the concentrations of the nutrient phosphorus to mitigate some of the instream ecological effects of eutrophication on the river; these effects were, for the most part, direct consequences of the excessive growth of aquatic macrophytes. The primary instrument effecting lower concentrations of phosphorus was to be strict control of phosphorus releases from four major wastewatertreatment plants in Westborough, Marlborough, Hudson, and Maynard, Massachusetts. The improvements to be achieved from implementing this control were lower concentrations of total and dissolved phosphorus in the river, a 50-percent reduction in aquatic-plant biomass, a 30-percent reduction in episodes of dissolved oxygen supersaturation, no low-flow dissolved oxygen concentrations less than 5.0 milligrams per liter, and a 90-percent reduction in sediment releases of phosphorus to the overlying water. In 2007, the U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection, initiated studies to evaluate conditions in the Assabet River prior to the upgrading of wastewater-treatment plants to remove more phosphorus from their effluents. The studies, completed in 2008, implemented a visual monitoring plan to evaluate the extent and biomass of the floating macrophyte Lemna minor (commonly known as lesser duckweed) in five impoundments and evaluated the potential for phosphorus flux from sediments in impounded and free-flowing reaches of the river. Hydrologically, the two study years 2007 and 2008 were quite different. In 2007, summer streamflows, although low, were higher than average, and in 2008, the flows were generally higher than in 2007. Visually, the effects of these streamflow differences on the distribution of Lemna were obvious. In 2007, large amounts of floating macrophytes accumulated behind bridge constrictions and dams; in 2008, high flows during the early part of the growing season carried floating macrophytes past bridges and over dams, minimizing accumulations. Samples of Lemna were collected and weighed to provide an estimate of Lemna biomass based on areal coverage during the summer growing seasons at eight sites in the five impoundments. Average estimated biomass during 2007 was approximately twice the 2008 biomass in each of the areas monitored. In 2007, in situ hyperspectral and high-resolution, multispectral data from the IKONOS satellite were obtained to evaluate the feasibility of using remote sensing to monitor the extent of aquatic plant growth in Assabet River impoundments. Three vegetation indices based on light reflectance were used to develop metrics with which the hyperspectral and satellite data were compared. The results of the comparisons confirmed that the high-resolution satellite imagery could differentiate among the common aquatic-plant associations found in the impoundments. The use of satellite imagery could counterbalance emphasis on the subjective judgment of a human observer, and airborne hyperspectral data can provide higher resolution imagery than multispectral satellite data. In 2007 and 2008, the potential for sediment flux of phosphorus was examined in free-flowing reaches of the river and in the two largest impoundments-Hudson and Ben Smith. These studies were undertaken to determine in situ flux rates prior to the implementation of the Assabet River Total Maximum Daily Load (TMDL) for phosphorus and to compare these rates with those used in the development and evaluation of the TMDL. Water samples collected from a chamber placed on the river bottom were analyzed for total phosphorus and orthophosphorus. Ambient dissolved oxygen concentrations and seasonal temperature differences appeared to affect the rates of sequestration and sediment release of phosphorus. When dissolved oxygen concentrations remained relatively high in the chambers and when the temperature was relatively low, the tendency was for phosphorus concentrations to decrease in the chambers, indicating sediment sequestration of phosphorus; when dissolved oxygen concentrations dropped to near zero and temperatures were warmest, phosphorus concentrations increased in the chambers, indicating phosphorus flux from the sediment. The rates of release and sequestration in the in situ studies were generally comparable with the rates determined in laboratory studies of Assabet River sediment cores for State and Federal agencies. Sediment-core and chamber studies produced substantial sediment fluxes to the water column only under extremely low-DO or anaerobic conditions rarely found in the Assabet River impoundments; thus, sediment is not likely to be a major phosphorus source, especially when compared to the wastewater effluent, which sustains higher ambient concentrations. The regulatory agencies now (2011) have substantial laboratory and field data with which to determine the required 90-percent reduction in phosphorus flux after the completion of upgrades to the wastewater-treatment plants that discharge to the Assabet River.

Massachusetts↗
USGS1968

Measurement of peak discharge by the slope-area method

This chapter describes application of the Manning equation to measure peak discharge in open channels. Field and office procedures limited to this method are described. Selection of reaches and cross sections is detailed, discharge equations are given, and a complete facsimile example of computation of a slope-area measurement is also given.

Techniques of Water-Resources Investigations↗
USGS1982

Water resources and data-network assessment of the Manasota Basin, Manatee and Sarasota Counties, Florida

The average annual rainfall in the Manasota Basin is 53.7 inches , and annual evapotranspiration is about 39 inches. Annual runoff from gaged parts of the Basin ranges from about 13 to 17 inches per year. Streamflow in the upland areas diminishes rapidly following the end of the rainy season and approaches zero during extended dry periods. Generally, surface water is of good quality except in tidally affected, coastal areas. Its quality varies seasonally, generally becoming more mineralized during the dry season. The principal hydrogeologic units are the surficial aquifer, the upper confining beds and minor artesian aquifers, the Floridan acquifer, and the lower confining bed. The quality of ground water is generally good except in the western and southern parts where saltwater intrusion or incomplete flushing of residual seawater has occurred. Land-use changes and stream impoundments and diversions require reassessment of the type and use of data collected by the surface-water network. Such changes may require modification of existing sites and establishment of new ones. Development and completion of the monitoring plan could provide most of the data necessary to define the groundwater system. (USGS)

Water-Resources Investigations Report↗
USGS1982

Intrusive rocks of the Holden and Lucerne quadrangles, Washington— The relation of depth zones, composition, textures, and emplacement of plutons

The core of the northern Cascade Range in Washington consists of Precambrian and upper Paleozoic metamorphic rocks cut by numerous plutons, ranging in age from early Triassic to Miocene. The older plutons have been eroded to catazonal depths, whereas subvolcanic rocks are exposed in the youngest plutons. The Holden and Lucerne quadrangles span a -sizeable and representative part of this core. The oldest of the formations mapped in these quadrangles is the Swakane Biotite Gneiss, which was shown on the quadrangle maps as Cretaceous and older in age. The Swakane has yielded a middle Paleozoic metamorphic age, and also contains evidence of zircon inherited from some parent material more than 1,650 m.y. old. In this report, the Swakane is assigned an early Paleozoic or older age. It consists mostly of biotite gneiss, but interlayered with it are scattered layers and lenses of hornblende schist and gneiss, clinozoisite-epidote gneiss, and quartzite. Thickness of the Swakane is many thousands of meters, and the base is not exposed. The biotite gneiss is probably derived from a pile of siliceous volcanic rocks containing scattered sedimentary beds and basalt flows. Overlying the Swakane is a thick sequence of eugeosynclinal upper Paleozoic rocks metamorphosed to amphibolite grade. The sequence includes quartzite and thin layers of marble, hornblende schist and gneiss, graphitic schist, and smaller amounts of schist and gneiss of widely varying compositions. The layers have been tightly and complexly folded, and, in places, probably had been thrust over the overlying Swakane prior to metamorphism. Youngest of the supracrustal rocks in the area are shale, arkosic sandstone, and conglomerate of the Paleocene Swauk Formation. These rocks are preserved in the Chiwaukum graben, a major structural element of the region. Of uncertain age, but possibly as old as any of the intrusive rocks in the area, are small masses of ultramafic rocks, now almost completely altered to serpentine. These occur either as included irregular masses in later intrusives or as tectonically emplaced lenses in metamorphic rocks. Also of uncertain age but probably much younger, perhaps as young as Eocene, are larger masses of hornblendite and hornblende periodotite that grade into hornblende gabbro. These are exposed on the surface and in the underground workings of the Holden mine. Oldest of the granitoid intrusives are the narrow, nearly concordant Dumbell Mountain plutons, having a radiometric age of about 220 m.y. They consist of gneissic hornblende-quartz diorite and quartz diorite gneiss. Most contacts consist of lit-par-lit zones, but some are gradational or more rarely sharp. The plutons are typically catazonal. Closely resembling the Dumbell Mountain plutons in outcrop appearance, but differing considerably in composition, are the Bearcat Ridge plutons. These consist of gneissic quartz diorite and granodiorite. The Bearcat Ridge plutons are not in contact with older dated plutons, but because their textural and structural characteristics so closely resemble those of the Dumbell Mountain plutons, they are considered to be the same age. Their composition, however, is suggestive of a much younger age. Cutting the Dumbell Mountain plutons is the Leroy Creek pluton, consisting of gneissic biotite-quartz diorite and trondjhemite. The gneissic foliation in the Leroy Creek is characterized by a strong and pervasive swirling. Cutting both the Dumbell Mountain and Leroy Creek plutons are the almost dikelike Seven-fingered Jack plutons. These range in composition from gabbro to quartz diorite; associated with them are contact complexes of highly varied rocks characterized by gabbro and coarse-grained hornblendite. Most of the rocks are gneissic, but some are massive and structureless. Dikes, sills, small stocks, and irregular clots of leucocratic quartz diorite and granodiorite are abundant in the Swakane Biotite Gneiss and are locally abundant in the Seven-fingered Jack and other plutons. Although the leucocratic rocks vary little in appearance or composition, some, particularly those in the Swakane, were formed by metamorphic segregation, whereas the others are probably felsic differentiates of intrusive rocks. The Tenpeak and White Mountain plutons are closely similar and are probably connected at depth. Rocks of the Tenpeak are more varied and range in composition from gabbro to granodiorite; quartz diorite is not only most common in the Tenpeak, but also constitutes, by far, the greatest bulk of the White Mountain pluton. Much of the rock in both plutons is somewhat gneissic, but some is nongneissic. The north end of the White Mountain pluton is bordered by a contact complex similar to those associated with the Seven-fingered Jack and other plutons in the area. Maximum potassium/argon ages determined on hornblende from the Tenpeak are about 90 m.y. Probably somewhat younger than the Tenpeak and White Mountain plutons is the Sulphur Mountain pluton. Only a small part of the pluton extends into the Holden quadrangle, and here the rocks are gneissic granodiorite. The High Pass and Buck Creek plutons are tabular, somewhat silllike masses of granodioritic and quartz dioritic composition. Rocks in the Buck Creek pluton are entirely gneissic, whereas rocks only near the contacts or in the thinner parts of the High Pass are gneissic. In most places, the contacts of both plutons consist of lit-par-lit zones, but numerous dikes of the High Pass are present in the host rocks, especially the Sulphur Mountain pluton. The Riddle Peaks pluton consists of layered and unlayered hornblende gabbro. Inasmuch as the pluton is cut on all sides by later intrusive rocks, its age relative to older plutons is not known, but it is almost certainly pre-Tertiary. Much of the gabbro is rhythmically layered, but some is unlayered or only vaguely layered. In places, thick sheets of unlayered gabbro alternate with equally thick sheets of rhythmically layered gabbro. The rock is mostly fresh and unaltered or recrystallized. No pseudosedimentary structures other than the gravity-stratified rhythmic layers were seen. The Cardinal Peak pluton has a core consisting largely of granodiorite and quartz diorite and a rim of contact complexes containing large amounts of gabbro and coarse-grained hornblendite. The northern part of the intrusive is highly protoclastic throughout and contains numerous spindle- and canoe-shaped masses a third of a meter to several meters across and a few meters to several tens of meters long that are either partly or completely enveloped by rinds of fine-grained protoclastic material. These masses seem to have behaved as roller bearings during intrusion of the partly crystalline magma.

Washington↗
USGS2004

Estimating hydraulic properties of the Floridan Aquifer System by analysis of earth-tide, ocean-tide, and barometric effects, Collier and Hendry Counties, Florida

Aquifers are subjected to mechanical stresses from natural, non-anthropogenic, processes such as pressure loading or mechanical forcing of the aquifer by ocean tides, earth tides, and pressure fluctuations in the atmosphere. The resulting head fluctuations are evident even in deep confined aquifers. The present study was conducted for the purpose of reviewing the research that has been done on the use of these phenomena for estimating the values of aquifer properties, and determining which of the analytical techniques might be useful for estimating hydraulic properties in the dissolved-carbonate hydrologic environment of southern Florida. Fifteen techniques are discussed in this report, of which four were applied. An analytical solution for head oscillations in a well near enough to the ocean to be influenced by ocean tides was applied to data from monitor zones in a well near Naples, Florida. The solution assumes a completely non-leaky confining unit of infinite extent. Resulting values of transmissivity are in general agreement with the results of aquifer performance tests performed by the South Florida Water Management District. There seems to be an inconsistency between results of the amplitude ratio analysis and independent estimates of loading efficiency. A more general analytical solution that takes leakage through the confining layer into account yielded estimates that were lower than those obtained using the non-leaky method, and closer to the South Florida Water Management District estimates. A numerical model with a cross-sectional grid design was applied to explore additional aspects of the problem. A relation between specific storage and the head oscillation observed in a well provided estimates of specific storage that were considered reasonable. Porosity estimates based on the specific storage estimates were consistent with values obtained from measurements on core samples. Methods are described for determining aquifer diffusivity by comparing the time-varying drawdown in an open well with periodic pressure-head oscillations in the aquifer, but the applicability of such methods might be limited in studies of the Floridan aquifer system.

Florida↗
USGS1963

Water resources of Red River Parish, Louisiana

Red River Parish is on the eastern flank of the Sabine uplift in northwestern Louisiana. The 'area is underlain by lignitic clay and sand of Paleocene and Eocene age which dip to the east at the rate of about 30 feet per mile. The Red River is entrenched in these rocks in the western part of the parish. Alternating valley filling and erosion during the Quaternary period have resulted in the present lowland with flanking terraces. In the flood-plain area moderate to large quantities of very hard, iron-bearing water, suitable for irrigation, are available to wells in the alluvial sand and gravel of Quaternary age. The aquifer ranges in thickness from 20 to slightly more than 100 feet. It is recharged by downward seepage of rainfall through overlying clay and silt, by inflow from older sands adjacent to and beneath the entrenched valley, and by infiltration from the streams where the water table is below stream level during flood stages or as a result of pumping. Water levels are highest in the middle of the valley. Ground water moves mainly toward the Red River on the east and Bayou Pierre on the west, but small amounts move down the valley. Computations based on water-level and aquifer-test data indicate that the Quaternary alluvium contains more than 330 billion gallons of ground water in storage and that the maximum discharge of ground water to the streams is slightly more than 30 mgd (million gallons per day). At times of high river stage, surface water flows into the aquifer at a rate that depends in part upon the height and duration of the river stage. Moderate supplies of soft, iron-bearing water may be obtained from dissected Pleistocene terrace deposits that flank the flood plains of the Red River and Black Lake Bayou. However, the quantity of water that can be pumped from these deposits varies widely from place to place because of differences in the areal extent and saturated thickness of the segments of the deposits; this extent and thickness are governed in turn by the amount of erosion the deposits have undergone. Beds of fine-grained lignitic sands of Tertiary age contain water of generally good quality to depths of 150 to 450 feet. The thinness and low permeability of the sands restrict their development to low-yield wells. Water from these sands in the western part of the parish, where they lie beneath the alluvial valley, is more mineralized than that from the younger Tertiary sands exposed in the east-central area. Streamflow records have been collected on the principal streams in Red River Parish since 1939. Additional spot low-flow data were obtained on several small streams originating within the parish for a study made in connection with the preparation of this report. Quality-of-water data for streams in the parish were collected on an occasional spot-sampling basis prior to and during this investigation. The largest source of surface water in the parish is the Red River, which drains approximately 63,400 square miles upstream from the parish. The Red River has an average flow of about 13,100 cfs (cubic feet per second), or about 8,500 mgd. Many of the streams that drain the upland area are not dependable sources of supply because their flows are not well sustained during dry seasons. The average annual precipitation over the parish is about 52 inches, of which about 17 inches becomes runoff; this runoff is equivalent to a continuous flow of about 1.25 cfs per square mile. Seasonal and annual runoff varies, but no significant trends have been noticed. The principal surface-water problems in the parish pertain to flood control, drainage, irrigation, and navigation. Flood problems have been alleviated considerably by the operation of Denison Dam (Lake Texoma), the completion of levees on the Red River, channel improvements on Bayou Pierre, and the completion of Wallace Lake reservoir on Cypress Bayou. There are wet lands along the Red River that would be very productive if properly drained

Water Supply Paper↗
USGS2010

The 2006 eruption of Augustine Volcano, Alaska

Augustine Volcano, the most historically active volcano in Alaska&rsquo;s Cook Inlet region, again showed signs of life in April 2005. Escalating seismic unrest, ground deformation, and gas emissions culminated in an eruption from January 11 to mid-March of 2006, the fifth major eruption in 75 years. The eruption began with a series of 13 short-lived blasts over 20 days that sent pyroclastic flows; snow, rock, and ice avalanches; and lahars down the volcano&rsquo;s snow clad flanks; ash clouds drifted hundreds of kilometers downwind. Punctuated explosive activity gave way to effusion of lava and emplacement of thick block-and-ash flows on the volcano&rsquo;s north flank that continued through mid-February. In mid-March renewed extrusion resulted in the building of a new, higher summit lava dome and two blocky lava flows on the north and northeast flanks of the cone. The eruption resulted in ash fall on many south-central Alaskan communities and disrupted air traffic in the region. Augustine&rsquo;s frequent eruptions and relatively easy access have long drawn volcanologists to study the accumulation, ascent, and eruption of andesitic to dacitic magma. Studies of the most recent activity before 2006, in 1976 and 1986, revealed that the volcano lately produces explosive eruptions that are preceded by months of unrest and injection of new magma into a storage region in the upper several kilometers of the crust. Each of these eruptions then followed a similar progression from explosive to effusive behavior over several months. Petrologic and geophysical observations suggest that these three eruptions were triggered by similar magma mixing events and that the subsequent ascent and eruption of magma was governed by processes that were roughly constant from one eruption to the next. Geologic studies of the island show that in the more distant past parts of Augustine&rsquo;s edifice have failed repeatedly, resulting in debris avalanches that entered the sea and, at least once, in 1883, caused a tsunami that hit surrounding Cook Inlet coastlines. Such edifice failures and resultant local tsunamis should be expected in the future. Recognition of Augustine&rsquo;s frequent activity and hazardous nature led to the installation of a network of telemetered seismometers beginning in 1971, the establishment of a geodetic network in 1988, and the installation of other new instrumentation such as pressure sensors, broadband seismometers, and cameras by the Alaska Volcano Observatory (AVO), and the selection of Augustine for geodetic instrumentation through the EarthScope/Plate Boundary Observatory program in 2004. In addition, remote sensing techniques, such as airborne thermal imaging and the advanced spaceborne thermal emission and reflection radiometer (ASTER), provided novel and often critical information as the 2006 eruption progressed. The combination of a long-term seismic network and an array of new monitoring techniques has provided a breadth and depth of understanding of Augustine&rsquo;s most recent activity that was not possible in the past. This volume contains 28 chapters reporting on a diverse suite of new scientific observations and investigations that were motivated by the 2006 eruption. Understanding the magmatic processes that drive eruptions, identifying eruptive events, tracking the movement of ash clouds, and communicating the resultant hazards to other government agencies and the public are all critical tasks for AVO, and chapters touch upon all of these topics. One goal in this compilation is to synthesize the diverse information into as complete an understanding of the magmatic and eruptive processes as possible. An equally important goal is to provide a framework for diagnosing periods of unrest and formulating forecasts of eruptions that will certainly take place at Augustine in the future. This latter goal is especially important, as Augustine&rsquo;s frequent eruptive activity suggests that another eruption can be expected within the next several decades. Consequently, the investigations in this volume are intended to provide both a means to better forecast future eruptive episodes and also an opportunity to formulate and test future hypotheses for magmatic and eruptive processes. Future eruptions may follow a course similar to those observed in 1976, 1986, and 2006. However, a major perturbation that upsets conditions within the magmatic system could occur, owing perhaps to the rise of a much larger or different parental magma or to a large edifice failure similar to the 1883 sector collapse. In such events, the comprehensive study of past eruptions will provide data critical to assessing the current state of the magmatic system. In assembling this volume we have sought as consistent and accurate a portrayal of the 2006 eruption as possible. We have asked all authors to refer to the same basic eruption chronology, unless their observations and data require alternative explanations. Naturally, not all techniques or methodologies produce a completely consistent set of observations, nor do the precise conclusions in every paper support one another. We have grouped chapters on the basis of discipline. Papers that focus on specific techniques, methodology, or instrumentation are placed throughout the volume where they best fit with others that rely on their results.

Alaska↗