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At least 1,603 records · Page 89Linked to original sources

USGS2014

A new look at the Lake Superior biomass size spectrum

We synthesized data from multiple sampling programs and years to describe the Lake Superior pelagic biomass size structure. Data consisted of Coulter counts for phytoplankton, optical plankton counts for zooplankton, and acoustic surveys for pelagic prey fish. The size spectrum was stable across two time periods separated by 5 years. The primary scaling or overall slope of the normalized biomass size spectra for the combined years was −1.113, consistent with a previous estimate for Lake Superior (−1.10). Periodic dome structures within the overall biomass size structure were fit to polynomial regressions based on the observed sub-domes within the classical taxonomic positions (algae, zooplankton, and fish). This interpretation of periodic dome delineation was aligned more closely with predator–prey size relationships that exist within the zooplankton (herbivorous, predacious) and fish (planktivorous, piscivorous) taxonomic positions. Domes were spaced approximately every 3.78 log10 units along the axis and with a decreasing peak magnitude of −4.1 log 10 units. The relative position of the algal and herbivorous zooplankton domes predicted well the subsequent biomass domes for larger predatory zooplankton and planktivorous prey fish.

Lake Superior↗

USGS2015

Remote sensing systems – Platforms and sensors: Aerial, satellites, UAVs, optical, radar, and LiDAR

The American Society of Photogrammetry and Remote Sensing defined remote sensing as the measurement or acquisition of information of some property of an object or phenomenon, by a recording device that is not in physical or intimate contact with the object or phenomenon under study (Colwell et al., 1983). Environmental Systems Research Institute (ESRI) in its geographic information system (GIS) dictionary defines remote sensing as “collecting and interpreting information about the environment and the surface of the earth from a distance, primarily by sensing radiation that is naturally emitted or reflected by the earth’s surface or from the atmosphere, or by sending signals transmitted from a device and reflected back to it (ESRI, 2014).” The usual source of passive remote sensing data is the measurement of reflected or transmitted electromagnetic radiation (EMR) from the sun across the electromagnetic spectrum (EMS); this can also include acoustic or sound energy, gravity, or the magnetic field from or of the objects under consideration. In this context, the simple act of reading this text is considered remote sensing. In this case, the eye acts as a sensor and senses the light reflected from the object to obtain information about the object. It is the same technology used by a handheld camera to take a photograph of a person or a distant scenic view. Active remote sensing, however, involves sending a pulse of energy and then measuring the returned energy through a sensor (e.g., Radio Detection and Ranging [RADAR], Light Detection and Ranging [LiDAR]). Thermal sensors measure emitted energy by different objects. Thus, in general, passive remote sensing involves the measurement of solar energy reflected from the Earth’s surface, while active remote sensing involves synthetic (man-made) energy pulsed at the environment and the return signals are measured and recorded.

Book chapter↗

USGS1979

Geology of the offshore Southeast Georgia Embayment, U.S. Atlantic continental margin, based on multichannel seismic reflection profiles

A geologic interpretation of the offshore Southeast Georgia Embayment is based on an 1,100-km multichannel seismic reflection survey conducted jointly by the University of Texas Marine Science Institute and the U.S. Geological Survey. The Southeast Georgia Embayment consists of a wedge of Cretaceous and Cenozoic sedimentary rocks that thins from 5 to 8 km beneath the Blake Plateau to about 1 km over the Cape Fear Arch. North of about 31°N lat. the sedimentary section onlaps a regional unconformity characterized by a strong, smooth reflector/high-velocity refractor (5.8 to 6.3 km/sec). Rocks below the unconformity may consist of Lower Jurassic volcanic(?) rocks, crystalline basement, or a high-velocity sedimentary layer. Acoustic basement south of 31°N lat. is an i regular unconformable surface that probably truncates a varied lithology consisting of Paleozoic (and Precambrian?) igneous, metamorphic, and sedimentary rocks or Triassic to Early Jurassic igneous and sedimentary rocks in fault basins, all of which crop out or have been drilled onshore. The sedimentary section is divided into three major seismic intervals. The intervals are separated by unconformities and can be mapped regionally. The oldest interval ranges in age from Early Cretaceous through middle Late Cretaceous, although it may contain Jurassic rocks where it thickens beneath the Blake Plateau. It probably consists of continental to nearshore clastic rocks where it onlaps basement and grades seaward to a restricted carbonate platform facies (dolomite-evaporite). The middle interval (Upper Cretaceous) is characterized by prograding clinoforms interpreted as open marine slope deposits. This interval represents a Late Cretaceous shift of the carbonate shelf margin from the Blake Escarpment shoreward to about its present location, probably due to a combination of co tinued subsidence, an overall Late Cretaceous rise in sea level, and strong currents across the Blake Plateau. The youngest (Cenozoic) interval represents a continued seaward progradation of the continental shelf and slope. Cenozoic sedimentation on the Blake Plateau was much abbreviated owing mainly to strong currents.

Southeast Georgia Embayment↗

USGS2010

2009 Spawning cisco investigations in the Canadian waters of Lake Superior

We sampled with acoustics (AC) and midwater trawls (MT) to determine cisco abundance in Lake Superior’s Thunder and Black bays during 8-14 November, 2009. Total abundance of spawning-size (≥ 250 mm total length) ciscoes was estimated at 6.25 million in Thunder Bay and 1.12 million in Black Bay. Exploitation fractions of market-size (≥ age 6) females from Thunder and Black bays for 2009 were estimated at 7.1% and 11.3%, respectively; below the recommended maximum annual harvest of 15% recently adopted by Lake Superior fisheries managers. Given Thunder Bay spawner densities are on a downward trajectory, and recruitment since the 2003 year-class has been low, it is likely the exploitation fractions will increase in the future. After 2010, the Ontario Ministry of Natural Resources (OMNR) will carry on the AC program as a management activity. It is likely suspended experimental gill net (GN) samples will be used to ground truth future AC samples. In 2009, we characterized the length and age structure of Thunder Bay ciscoes using both MT samples and GN samples. Females represented 49% of the MT catch, but only 39% in GN samples. Catching a smaller proportion of females in GN samples resulted in a lower female population estimate and a higher estimated exploitation fraction (10.4%) compared to MT samples (7.1%). Experimental gill net effort was limited to 10-11.8 m water column depths where midwater trawl samples also caught roughly 40% females. Ciscoes ≥ age 17 (≥ 1992 year class) were common in Black Bay, but rare in Thunder Bay suggesting: 1) the stocks may be distinct; and 2) total mortality of ciscoes returning to spawn in Black Bay in recent years has been lower than ciscoes returning to Thunder Bay. Our mid-November 2009 effort to assess the Black Bay stock by sampling outside of the 3 bay in the lake proper was deemed successful, but this should be confirmed by sampling the Black Bay region during both mid- and late-November 2010.

Lake Superior↗

USGS2014

Mineral resource of the month: vermiculite

Vermiculite comprises a group of hydrated, laminar magnesium-aluminum-iron silicate minerals resembling mica. They are secondary minerals, typically altered biotite, iron-rich phlogopite or other micas or clay-like minerals that are themselves sometimes alteration products of amphibole, chlorite, olivine and pyroxene. Vermiculite deposits are associated with volcanic ultramafic rocks rich in magnesium silicate minerals, and flakes of the mineral range in color from black to shades of brown and yellow. The crystal structure of vermiculite contains water molecules, a property that is critical to its processing for common uses. Using a process called exfoliation-in which vermiculite flakes are heated to 900 degrees Celsius or higher, causing water within the flakes to flash to steam and expand-crude vermiculite ore is processed into particles that are eight to 20 times larger. The resulting lightweight material is chemically inert and fire resistant, with low density and low thermal conductivity. It is also odorless, has high liquid absorption capacity and catalytic properties. Because it is lightweight and thermally insulating, vermiculite is used in general building plasters and concrete products, alone or combined with other lightweight aggregates such as perlite. Special plasters, in which vermiculite is combined with binders like gypsum or portland cement, fillers or other additives, provide fire protection and soundproofing. As insulation, exfoliated vermiculite, sometimes treated with a water repellent, is used to fill pores and cavities in masonry construction and hollow blockwork to enhance acoustic properties, fire rating and insulation performance. Exfoliated vermiculite can also be used to produce refractory and insulation concretes and mortars, and to make high-temperature binders for construction materials, gaskets, specialty papers, textiles and vehicle brake linings. Finer grades of exfoliated vermiculite can be used to produce various shapes of insulation pellets, high-temperature insulation, as a primary component in cementitious coatings, and as a filler in inks, paints, plastics and other materials. Vermiculite can absorb liquids such as fertilizers, herbicides and insecticides, which can then be transported as free-flowing solids. It is used in the fertilizer and pesticide markets because of its ability to act as a bulking agent, carrier and extender. In horticulture, exfoliated vermiculite improves soil aeration and moisture retention, and when mixed with peat or other composted materials, such as pine bark, vermiculite produces a good growing medium for plants. As a soil conditioner, exfoliated vermiculite improves aeration in clay-rich soils and water retention in sandy soils, while reducing the likelihood of compaction, cracking and crusting of the soil. For more information on the commercial use of vermiculite, visit minerals.usgs.gov/minerals/ .

Earth↗

USGS2014

Dynamics and ecological consequences of the 2013−2014 koa moth outbreak at Hakalau Forest National Wildlife Refuge.

A massive outbreak of the koa moth (Geometridea: Scotorythra paludicola) defoliated more than a third of the koa (Acacia koa) forest on Hawai‘i Island during 2013−2014. This was the largest koa moth outbreak ever recorded and the first on the island since 1953. The outbreak spread to sites distributed widely around the island between 800−2,000 m elevation and in wet rainforest to dry woodland habitats. We monitored the outbreak at two windward forest sites (Laupāhoehoe and Saddle Road Kīpuka) and one leeward forest site (Kona), and we studied the dynamics of the outbreak and its impacts on the forest ecosystem at Hakalau Forest National Wildlife Refuge, our higher elevation windward site. Study sites at Hakalau included two stands of koa that were planted (reforestation stands) in former cattle pastureland about 20 years earlier and two stands of koa that were dominated by ‘ōhi‘a (Metrosideros polymorpha) and that were naturally recovering from cattle grazing (forest stands). We observed one outbreak at Hakalau, multiple outbreaks at the two other windward sites, but no outbreak at the leeward site. Caterpillars at Hakalau reached peak estimated abundances of more than 250,000 per tree and 18,000,000 per hectare, and they removed between 64−93% of the koa canopy in managed forest stands. Defoliation was more extensive in naturally recovering forest, where ‘ōhi‘a dominated and koa was less abundant, compared to the planted stands, where koa density was high. Koa trees were still growing new foliage six months after being defoliated, and leaves were produced in greater proportion to phyllodes, especially by small koa (≤ 8 cm dbh) and by larger trees in forest stands, where light levels may have remained relatively low after defoliation due to the high cover of ‘ōhi‘a. Small branches of many trees apparently died, and canopy regrowth was absent or low in 9% of koa trees and seedlings, which indicates the likely level of mortality. Between 2,000−5,000 kg/ha of frass fell during the defoliation event, resulting in the deposition of up to 200 kg/ha of highly labile nitrogen on the forest floor in less than two months. The deposition of nitrogen was detected as pulses in resin-available nitrogen in the top 5−10 cm of soil at two of three sites. These sites showed elevated soil nitrogen for about seven months. Nitrogen content of understory plant foliage, which is indicative of nitrogen uptake, suggested weak and variable effects of nitrogen deposition in the soil. Foliar nitrogen increased slightly in alien pasture grasses four months after the deposition of frass, although distinctive increases were not detected in native woody species. Birds responded to the abundance of caterpillars by increasing their activity in koa during the buildup of caterpillars and decreasing their use of koa after defoliation. During the outbreak, caterpillars increased in the diets of the two generalist insectivores we examined, and nearly all species gained weight. Bats responded to the abundance of moths by compression of active foraging into the first three hours of darkness each night after presumably having reached a digestive bottleneck. Reduced foraging activity by bats also resulted in lower indices of detectability based upon acoustic monitoring when compared to non-outbreak years. Parasitoid wasps tracked caterpillar abundance, but the low rate at which they attacked caterpillars suggests that they had little influence on the population. The predatory yellowjacket (Vespula pensylvanica) did not respond to the outbreak. Although a single, protracted outbreak occurred at Hakalau, multiple outbreaks and defoliations occurred at lower elevations. Our results provide a broad foundation for evaluating the dynamics and impacts of future Scotorythra outbreaks.

Hawaii↗

USGS2015

Using hydrophones as a surrogate monitoring technique to detect temporal and spatial variability in bedload transport

Collecting physical bedload measurements is an expensive and time-consuming endeavor that rarely captures the spatial and temporal variability of sediment transport. Technological advances can improve monitoring of sediment transport by filling in temporal gaps between physical sampling periods. We have developed a low-cost hydrophone recording system designed to record the sediment-generated noise (SGN) resulting from collisions of coarse particles (generally larger than 4 mm) in gravel-bedded rivers. The sound level of the signal recorded by the hydrophone is assumed to be proportional to the magnitude of bedload transport as long as the acoustic frequency of the SGN is known, the grain-size distribution of the bedload is assumed constant, and the frequency band of the ambient noise is known and can be excluded from the analysis. Each system has two hydrophone heads and samples at half-hour intervals. Ten systems were deployed on the San Joaquin River, California, and its tributaries for ten months during water year 2014, and two systems were deployed during a flood event on the Gunnison River, Colorado in 2014. A mobile hydrophone system was also tested at both locations to collect longitudinal profiles of SGN. Physical samples of bedload were not collected in this study. In lieu of physical measurements, several audio recordings from each site were aurally reviewed to confirm the presence or absence of SGN, and hydraulic data were compared to historical measurements of bedload transport or transport capacity estimates to verify if hydraulic conditions during the study would likely produce bedload transport. At one site on the San Joaquin River, the threshold of movement was estimated to have occurred around 30 m 3 /s based on SGN data. During the Gunnison River flood event, continuous data showed clockwise hysteresis, indicating that bedload transport was generally less at any given streamflow discharge during the recession limb of the hydrograph. Spatial variability in transport was also detected in the longitudinal profiles audibly and using signal processing algorithms. These experiments demonstrate the ability of hydrophone technology to capture the temporal and spatial variability of sediment transport, which may be missed when samples are collected using conventional methods.

California, Colorado↗

USGS1975

Quaternary faults at San Diego Bay, California

Acoustic-reflection profiles of subbottom strata reveal numerous faults that cut Quaternary deposits within and directly outside of San Diego Bay. These faults, together with previously mapped onshore faults, constitute the Rose Canyon fault zone that forms the local west boundary of the Santa Ana tectonic block, which is bounded on the east by the Elsinore fault zone. The minor earthquakes that have been felt in San Diego during historic time and accurately recorded during the past 41 yr are too infrequent to explain the observed rate of slip. The principal faulting is inferred to take place during moderate earthquakes similar to previous ones recorded along the west side of the Santa Ana block in 1933 at Long Beach, Calif., and in 1956 at San Miguel, Baja California. The known magnitudes of these previous events suggest that earthquakes in San Diego could attain a magnitude of approximately 6.5. An offset of the coast at Point La Jolla, when divided by the offset associated with previously studied earthquakes of magnitude 6.5, suggests that such events occur there at an average of approximately once every 600 yr.

California↗

USGS2009

Discharge and other hydraulic measurements for characterizing the hydraulics of Lower Congo River

The first direct measurements of discharge of the Lower Congo River below Malebo Pool and upstream from Kinganga, Democratic Republic of Congo (DRC) were made in July 2008 using acoustic Doppler current profilers, differential GPS, and echo sounders. These measurements were made in support of research that is attempting to understand the distribution of fish species in the Lower Congo River and reasons for separation of species within this large river. Analyses of these measurements show that the maximum depth in the Lower Congo River was in excess of 200 m and maximum water velocities were greater than 4 m/s. The discharge measured near Luozi, DRC was 35,800 m3/s, and decreased slightly beginning midway through the study. Local bedrock controls seem to have a large effect on the flow in the river, even in reaches without waterfalls and rapids. Dramatic changes in bed topography are evident in transects across the river.

Congo River and Malebo Pool↗

USGS2012

Expanding biological data standards development processes for US IOOS: visual line transect observing community for mammal, bird, and turtle data

The US Integrated Ocean Observing System (IOOS) has recently adopted standards for biological core variables in collaboration with the US Geological Survey/Ocean Biogeographic Information System (USGS/OBIS-USA) and other federal and non-federal partners. In this Community White Paper (CWP) we provide a process to bring into IOOS a rich new source of biological observing data, visual line transect surveys, and to establish quality data standards for visual line transect observations, an important source of at-sea bird, turtle and marine mammal observation data. The processes developed through this exercise will be useful for other similar biogeographic observing efforts, such as passive acoustic point and line transect observations, tagged animal data, and mark-recapture (photo-identification) methods. Furthermore, we suggest that the processes developed through this exercise will serve as a catalyst for broadening involvement by the larger marine biological data community within the goals and processes of IOOS.

Conference Paper↗

USGS2010

Large-scale laboratory testing of bedload-monitoring technologies: Overview of the StreamLab06 Experiments

A 3-month-long, large-scale flume experiment involving research and testing of selected conventional and surrogate bedload-monitoring technologies was conducted in the Main Channel at the St. Anthony Falls Laboratory under the auspices of the National Center for Earth-surface Dynamics. These experiments, dubbed StreamLab06, involved 25 researchers and volunteers from academia, government, and the private sector. The research channel was equipped with a sediment-recirculation system and a sediment-flux monitoring system that allowed continuous measurement of sediment flux in the flume and provided a data set by which samplers were evaluated. Selected bedload-measurement technologies were tested under a range of flow and sediment-transport conditions. The experiment was conducted in two phases. The bed material in phase I was well-sorted siliceous sand (0.6-1.8 mm median diameter). A gravel mixture (1-32 mm median diameter) composed the bed material in phase II. Four conventional bedload samplers – a standard Helley-Smith, Elwha, BLH-84, and Toutle River II (TR-2) sampler – were manually deployed as part of both experiment phases. Bedload traps were deployed in study Phase II. Two surrogate bedload samplers – stationarymounted down-looking 600 kHz and 1200 kHz acoustic Doppler current profilers – were deployed in experiment phase II. This paper presents an overview of the experiment including the specific data-collection technologies used and the ambient hydraulic, sediment-transport and environmental conditions measured as part of the experiment. All data collected as part of the StreamLab06 experiments are, or will be available to the research community.

Book chapter↗

USGS2009

The effect of channel shape, bed morphology, and shipwrecks on flow velocities in the Upper St. Clair River

In the Great Lakes of North America, the St. Clair River is the major outlet of Lake Huron and conveys water to Lake St. Clair which then flows to Lake Erie. One major topic of interest is morphological change in the St. Clair River and its impact on water levels in the Upper Great Lakes and connecting channel flows. A combined multibeam echosounder (MBES) bathymetric survey and acoustic Doppler current profiler (ADCP) flow survey of the outlet of Lake Huron and the Upper St. Clair River was conducted July 21-25, 2008. This paper presents how channel morphology and shipwrecks affect the flow in the Upper St. Clair River. The river is most constricted at the Blue Water Bridge near Port Huron, Michigan, with water velocities over 2 ms-1 for a flow of 5,200 m 3 s-1. Downstream of this constriction, the river flows around a bend and expands creating a large recirculation zone along the left bank due to flow separation. This recirculation zone reduces the effective channel width, and thus increases flow velocities to over 2 ms-1 in this region. The surveys reveal several shipwrecks on the bed of the St. Clair River, which possess distinct wakes in their flow velocity downstream of the wrecks. The constriction and expansion of the channel, combined with forcing of the flow by bed topography, initiates channel-scale secondary flow, creating streamwise vortices that maintain coherence downstream over a distance of several channel widths.

Upper St. Clair River↗

USGS2009

Velocity mapping in the Lower Congo River: A first look at the unique bathymetry and hydrodynamics of Bulu Reach

The lower Congo River is one of the deepest, most powerful, and most biologically diverse stretches of river on Earth. The river’s 270 m decent from Malebo Pool though the gorges of the Crystal Mountains to the Atlantic Ocean (498 km downstream) is riddled with rapids, cataracts, and deep pools. Much of the lower Congo is a mystery from a hydraulics perspective. However, this stretch of the river is a hotbed for biologists who are documenting evolution in action within the diverse, but isolated, fish populations. Biologists theorize that isolation of fish populations within the lower Congo is due to barriers presented by flow structure and bathymetry. To investigate this theory, scientists from the U.S. Geological Survey and American Museum of Natural History teamed up with an expedition crew from National Geographic in 2008 to map flow velocity and bathymetry within target reaches in the lower Congo River using acoustic Doppler current profilers (ADCPs) and echo sounders. Simultaneous biological and water quality sampling was also completed. This paper presents some preliminary results from this expedition, specifically with regard to the velocity structure andbathymetry. Results show that the flow in the bedrock controlled Bulu reach of the lower Congo is highly energetic. Turbulent and secondary flow structures can span the full depth of flow (up to 165 m), while coherent bank-to-bank cross-channel flow structures are absent. Regions of flow separation near the banks are isolated from one another and from the opposite bank by high shear, high velocity zones with depth-averaged flow velocities that can exceed 4 m/s.

Lower Congo River↗

USGS2010

Measurement of bedload transport in sand-bed rivers: A look at two indirect sampling methods

Sand-bed rivers present unique challenges to accurate measurement of the bedload transport rate using the traditional direct sampling methods of direct traps (for example the Helley-Smith bedload sampler). The two major issues are: 1) over sampling of sand transport caused by “mining” of sand due to the flow disturbance induced by the presence of the sampler and 2) clogging of the mesh bag with sand particles reducing the hydraulic efficiency of the sampler. Indirect measurement methods hold promise in that unlike direct methods, no transport-altering flow disturbance near the bed occurs. The bedform velocimetry method utilizes a measure of the bedform geometry and the speed of bedform translation to estimate the bedload transport through mass balance. The bedform velocimetry method is readily applied for the estimation of bedload transport in large sand-bed rivers so long as prominent bedforms are present and the streamflow discharge is steady for long enough to provide sufficient bedform translation between the successive bathymetric data sets. Bedform velocimetry in small sandbed rivers is often problematic due to rapid variation within the hydrograph. The bottom-track bias feature of the acoustic Doppler current profiler (ADCP) has been utilized to accurately estimate the virtual velocities of sand-bed rivers. Coupling measurement of the virtual velocity with an accurate determination of the active depth of the streambed sediment movement is another method to measure bedload transport, which will be termed the “virtual velocity” method. Much research remains to develop methods and determine accuracy of the virtual velocity method in small sand-bed rivers.

Missouri↗

USGS2012

Status and trends of pelagic prey fishes in Lake Huron, 2012

The USGS Great Lakes Science Center (GLSC) conducted acoustic/midwater trawl surveys of Lake Huron during 1997 and annually during 2004-2012. The 2012 survey was conducted during September and October, and included transects in Lake Huron’s Main Basin, Georgian Bay, and North Channel. Pelagic fish density (638 fish/ha) was lower in 2012 compared to 2011, with density in 2012 only 34% of 2011. Total biomass in 2012 was 74% of the 2011 value. Alewife Alosa pseudoharengus remained nearly absent, and only one cisco Coregonus artedi was captured. Rainbow smelt Osmerus mordax density was only 31% of the 2011 density. Bloater Coregonus hoyi density was less than half the 2011 density, mostly as a result of lower density of small bloater. Density and biomass of large bloater in 2012 were similar to 2011 levels. During 2012 we observed significantly higher fish biomass in North Channel than in the Main Basin or Georgian Bay. Prey availability during 2013 will likely be similar to 2012. Lake Huron now has pelagic fish biomass similar to that observed in recent lakewide acoustic surveys of Lake Michigan and Lake Superior, but species composition differs in the three lakes. There is an increasing diversity and prevalence of native species gradient from Lake Michigan to Lake Superior, with Lake Huron being intermediate in the prevalence of native fish species like coregonines and emerald shiner Notropis atherinoides.

Report↗

USGS2013

Status and trends of pelagic prey fishes in Lake Huron, 2012

Lake Huron↗

USGS2015

Geohydrologic and water-quality characterization of a fractured-bedrock test hole in an area of Marcellus shale gas development, Tioga County, Pennsylvania

An integrated analysis of core, geophysical logs, gas isotopes, and specific-depth water-quality samples from the Cherry Flats test hole was used to characterize the stratigraphy, water-bearing zones, and groundwater quality at a site in southern Tioga County, Pennsylvania. The study was completed as a cooperative effort between the Pennsylvania Department of Natural Resources, Bureau of Topographic and Geologic Survey (BTGS) and the U.S. Geological Survey (USGS). The multi-disciplinary characterization of the test hole provided information to aid the bedrock mapping of the Cherry Flats 7.5-minute quadrangle by BTGS, and to help quantify the depth and character of fresh and saline groundwater in an area of shale-gas exploration. The Cherry Flats test hole was cored to a depth of 1,513 feet (ft) below land surface (bls) and cased to 189 ft through the collapsed mine workings of the former Arnot No. 2 underground coal mine. The test hole penetrated 128.0 ft of Allegheny Formation and 154.1 ft of Pottsville Formation of Pennsylvanian age, 564.8 ft of Huntley Mountain Formation of Mississippian and Devonian age, and 666.3 ft of Catskill Formation of Devonian age. Core recovery was nearly 100 percent, except where complete core loss occurred from a depth of 1,231.1 to 1,240.8 ft. Several coal beds and mined-out coal horizons were penetrated in the Allegheny and Pottsville Formations. The test hole penetrated the entire thickness of the Huntley Mountain Formation and was completed in the middle part of the Catskill Formation. Bedding features penetrated by the test hole were estimated to have a strike of 021 degrees and dip about 1.7 degrees to the southeast, consistent with the test-hole location on the north limb of the Blossburg syncline. Most fractures penetrated by the test hole were parallel to bedding, with steeply dipping fractures present but much less common. Fracture density, determined from optical televiewer, acoustic televiewer, and video logs, generally increased with depth from the base of casing to about 400 ft bls, then decreased with depth to the bottom of the hole except for an increase from 506 to 568 ft bls. Very few fractures were penetrated from 600 to 850 ft. The depths of fresh and saline water-bearing zones were identified in the test hole by geophysical-log analysis and, for inflow zones, verified by specific-depth groundwater sampling by the use of a wire-line point sampler. Under ambient conditions and during pumping of the test hole, fresh water entered the hole from fractures at 567 and 580.5 ft bls, within grayish-red siltstone and greenish-gray sandstone, respectively, and flowed upward and exited at fractures from 303 to 319.5 ft; a very minor amount exited into fractures within coal beds at 240.4 and 252 ft bls. Transmissivity, estimated from analysis of the specific-capacity data and flowmeter logs, was about 18 ft2/d for the fracture zones from 567 to 580.5 ft and 6.7 ft2/d for fracture zones from 240.4 to 252 ft bls. The analysis estimated the hydraulic head of the lower zone and that of the upper flow zone was 8 ft higher and 37 ft lower than the composite water level in the test hole, respectively. Water samples of the freshwater inflow from zones at 567 to 580.5 ft bls had a total dissolved solids concentration of 577 mg/L indicating that these zone are in the lower part of the active groundwater flow system. Below the freshwater-bearing zone at 580.5 ft, the flowmeter did not detect any vertical flow in the test hole, and the gradient of the temperature log approached the geothermal gradient, indicating little ambient fluid flow and minimal fracture transmissivity below this depth. However, small seeps of saline water having total dissolved solids concentrations of greater than about 6,200 mg/L at 945 and 946 ft bls, from dark-greenish-gray to greenish-gray silty beds, were delineated by a time series of specific conductancelogs and observed on the video log. A wat

Pennsylvania↗

USGS2011

Exxon Valdez oil spill restoration project final report: Prince William Sound Herring disease program (HDP), restoration project 070819

Surveys of pathogens in Pacific herring from 2007 – 2010 indicated that Ichthyophonus , viral hemorrhagic septicemia virus, and erythrocytic necrosis virus are endemic in Prince William Sound and throughout the NE Pacific. Laboratory studies with VHSV indicated that multiple herring stocks are equally susceptible to the resulting disease, Pacific herring shed copious levels of VHSV (as high at 5x10 8 plaque-forming units/day) shortly after exposure, chronic and persistent infections can occur in Pacific herring, susceptibility of Pacific herring to VHS extends to the larval life stages but not the embryonic stages, and the prior exposure history of Pacific herring to VHSV can be determined post hoc. Laboratory studies involving Ichthyophonus indicated that schizonts can be inactivated with chlorine and iodine solutions, the parasite can survive for extended periods in saltwater but not freshwater, a low potential exists for cross contamination between in vitro explant cultures, infectious schizonts are released from the skin surface of infected herring, schizonts are not uniformly distributed throughout the skeletal muscle of infected Pacific herring, multiple types of Ichthyophonus exist with different genotypes and phenotypic traits, and temperature is an important factor influencing the infectivity of Ichthyophonus . Additional field and laboratory studies indicated that Ichthyophonus negatively influences the swimming performance of infected hosts and the negative impacts effects are exacerbated by increasing temperatures, American shad are an important reservoir of Ichthyophonus in the NE Pacific, Pacific herring are not susceptible to infectious hematopoietic necrosis (IHN), and Pacific herring will accept surgically implanted acoustic tags with negligible impacts on survival.

Alaska, Washington↗