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Sample records for lakes area northwestern

  1. The Impact of Eutrophication on Mercury Cycling in Lake 227 at the Experimental Lakes Area in Northwestern Ontario

    NASA Astrophysics Data System (ADS)

    Kirk, J.; Lehnherr, I.; Gleason, A.; St. Louis, V. L.; Muir, D.

    2012-12-01

    Mercury (Hg) is a pollutant of global concern as concentrations of methyl mercury (MeHg), the toxic and bioaccumulative form of Hg, are often present in fish at levels high enough to pose health risks to consumers. Although we are beginning to understand the factors controlling MeHg production in freshwater lakes, the impacts of environmental disturbances, such as eutrophication, on Hg cycling are not known. As part of a larger project examining controls on eutrophication, we are studying Hg cycling and MeHg production in the artificially eutrophied Lake 227 at the Experimental Lakes Area in northwestern Ontario. In addition to 40 years of ancillary data, Lake 227 is ideal for this study as it has an anoxic hypolimnion which may be an important zone of microbial MeHg production. To determine sources and losses of inorganic Hg(II) and MeHg from the lake, we are using a mass balance approach including: detailed lake profiles to determine the water column pools of Hg(II) and MeHg, Hg(II) and MeHg inputs via precipitation, and losses of Hg(II) and MeHg from the lake via gaseous elemental Hg(0) evasion and MeHg photodemethylation, respectively. Rates of water column MeHg production are also being determined using Hg stable isotope tracer experiments. 2010-2011 water column profiles demonstrated that although total Hg (THg) and MeHg concentrations were fairly low in Lake 227 surface waters (2.42 ± 0.64 and 0.11 ± 0.06 ng/L, respectively), MeHg concentrations (1.08 ± 0.39 ng/L) and the % THg that was MeHg (16 ± 5%) were high in deep regions of the water column (6-9 m). The zone of elevated water column MeHg expanded throughout summers 2010-2011, closely following the zone of anoxia, suggesting MeHg is produced in the anoxic hypolimnion. The zone of high particulate-bound THg (62 ± 6%) also migrated with the zone of anoxia over the summer suggesting that particle sinking and sediment resuspension, which are controlled by the timing of algal blooms, are important

  2. Source-receptor relationships for speciated atmospheric mercury at the remote Experimental Lakes Area, northwestern Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Cheng, I.; Zhang, L.; Blanchard, P.; Graydon, J. A.; St. Louis, V. L.

    2012-02-01

    Source-receptor relationships for speciated atmospheric mercury measured at the Experimental Lakes Area (ELA), northwestern Ontario, Canada were investigated using various receptor-based approaches. The data used in this study include gaseous elemental mercury (GEM), mercury bound to fine airborne particles (<2.5 μm) (PHg), reactive gaseous mercury (RGM), major inorganic ions, sulphur dioxide, nitric acid gas, ozone, and meteorological variables, all of which were measured between May 2005 and December 2006. The source origins identified were related to transport of industrial and combustion emissions (associated with elevated GEM), photochemical production of RGM (associated with elevated RGM), road-salt particles with absorption of gaseous Hg (associated with elevated PHg and RGM), crustal/soil emissions, and background pollution. Back trajectory modelling illustrated that a remote site, like ELA, is affected by distant Hg point sources in Canada and the United States. The sources identified from correlation analysis, principal components analysis and K-means cluster analysis were generally consistent. The discrepancies between the K-means and Hierarchical cluster analysis were the clusters related to transport of industrial/combustion emissions, photochemical production of RGM, and crustal/soil emissions. Although it was possible to assign the clusters to these source origins, the trajectory plots for the Hierarchical clusters were similar to some of the trajectories belonging to several K-means clusters. This likely occurred because the variables indicative of transport of industrial/combustion emissions were elevated in at least two or more of the clusters, which means this Hg source was well-represented in the data.

  3. Source-receptor relationships for speciated atmospheric mercury at the remote experimental lakes area, Northwestern Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Cheng, I.; Zhang, L.; Blanchard, P.; Graydon, J. A.; St. Louis, V. L.

    2011-12-01

    Source-receptor relationships for speciated atmospheric mercury measured at the Experimental Lakes Area (ELA), Northwestern Ontario, Canada were investigated using various receptor-based approaches. The data used in this study include gaseous elemental mercury (GEM), mercury bound to fine airborne particles (< 2.5 μm) (PHg), reactive gaseous mercury (RGM), major inorganic ions, sulphur dioxide, nitric acid gas, ozone, and meteorological variables, all of which were measured between May 2005 and December 2006. The source origins identified were related to transport of industrial and combustion emissions (associated with elevated GEM), photochemical production of RGM (associated with elevated RGM), road-salt particles with adsorption of gaseous Hg (associated with elevated PHg and RGM), crustal/soil emissions, and background pollution. Back trajectory modelling illustrated that a remote site, like the ELA, is affected by distant Hg point sources in Canada and the United States. The sources identified from correlation analysis, principal components analysis and K-means cluster analysis were generally consistent. The discrepancies between the K-means and Hierarchical cluster analysis were the clusters related to transport of industrial/combustion emissions, photochemical production of RGM, and crustal/soil emissions. Although it was possible to assign the clusters to these source origins, the trajectory plots for the Hierarchical clusters were similar to some of the trajectories belonging to several K-means clusters. This likely occurred because the variables indicative of transport of industrial/combustion emissions were elevated in at least two or more of the clusters, which means this Hg source was well-represented in the data.

  4. A multi-characteristic based algorithm for classifying vegetation in a plateau area: Qinghai Lake watershed, northwestern China

    NASA Astrophysics Data System (ADS)

    Ma, Weiwei; Gong, Cailan; Hu, Yong; Li, Long; Meng, Peng

    2015-10-01

    Remote sensing technology has been broadly recognized for its convenience and efficiency in mapping vegetation, particularly in high-altitude and inaccessible areas where there are lack of in-situ observations. In this study, Landsat Thematic Mapper (TM) images and Chinese environmental mitigation satellite CCD sensor (HJ-1 CCD) images, both of which are at 30m spatial resolution were employed for identifying and monitoring of vegetation types in a area of Western China——Qinghai Lake Watershed(QHLW). A decision classification tree (DCT) algorithm using multi-characteristic including seasonal TM/HJ-1 CCD time series data combined with digital elevation models (DEMs) dataset, and a supervised maximum likelihood classification (MLC) algorithm with single-data TM image were applied vegetation classification. Accuracy of the two algorithms was assessed using field observation data. Based on produced vegetation classification maps, it was found that the DCT using multi-season data and geomorphologic parameters was superior to the MLC algorithm using single-data image, improving the overall accuracy by 11.86% at second class level and significantly reducing the "salt and pepper" noise. The DCT algorithm applied to TM /HJ-1 CCD time series data geomorphologic parameters appeared as a valuable and reliable tool for monitoring vegetation at first class level (5 vegetation classes) and second class level(8 vegetation subclasses). The DCT algorithm using multi-characteristic might provide a theoretical basis and general approach to automatic extraction of vegetation types from remote sensing imagery over plateau areas.

  5. Abundances of northwestern salamander larvae in montane lakes with and without fish, Mount Rainier National Park, Washington

    USGS Publications Warehouse

    Larson, Gary L.; Hoffman, Robert L.

    2002-01-01

    In Mount Rainier National Park, the northwestern salamander usually inhabits relatively large and deep lakes and ponds (average size = 0.3 ha; average depth > 2 m) that contain flocculent, organic bottom sediments and abundant coarse wood. Prior to 1970, salmonids were introduced into many of the park's lakes and ponds that were typical habitat of the northwestern salamander. The objective of this study was to compare, in lakes and ponds with suitable habitat characteristics for northwestern salamanders, the observed abundances of larvae in takes and ponds with and without these introduced salmonids. Day surveys of 61 lakes were conducted between 1993 and 1999. Fish were limited to takes and ponds deeper than 2 in. For the 48 lakes and ponds deeper than 2 in (i.e., 25 fishless lakes and 23 fish lakes), the mean and median observed abundances of northwestern salamander larvae in fishless lakes and ponds was significantly greater than the mean and median observed abundances of larvae in lakes and ponds with fish. Northwestern salamander larvae were not observed in 11 fish lakes. These lakes were similar in median elevation, surface area, and maximum depth to the fishless lakes. The 12 fish lakes with observed larvae were significantly lower in median elevation, larger in median surface area, and deeper in median maximum depth than the fishless lakes. Low to null observed abundances of northwestern salamander larvae in lakes and ponds with fish were attributed to a combination of fish predation of larvae and changes in larval behavior.

  6. Survival rates of adult lake trout in northwestern Lake Michigan, 1983-1993

    USGS Publications Warehouse

    Fabrizio, Mary C.; Holey, Mark E.; McKee, Patrick C.; Toneys, Michael L.

    1997-01-01

    The restoration of lake trout Salvelinus namaycush in Lake Michigan has been an elusive goal of resource management agencies in the Great Lakes region. In this study, we estimated annual survival rates of adult lake trout from an area in northwestern Lake Michigan known as the Clay Banks refuge. We tagged and recaptured fish with gill nets during the fall spawning season (N = 12,175; 1983–1989 and 1991–1993) and with pound nets in the spring (N = 52,035; 1984–1990 and 1992–1993). We fit Cormack–Jolly–Seber models to the two sets of data. We had insufficient data to analyze annual differences in survival rates of fall-tagged fish, but we were able to estimate an overall annual survival rate of 0.67. Annual survival rates of spring-tagged fish varied between 0.53 and 0.88 and increased after 1987–1988. In addition to the mark–recapture studies, we analyzed catch rates of lake trout from gill-net and pound-net surveys to estimate survival rates using catch curve analyses; these annual rates were generally lower than those estimated from mark–recapture analyses of tagged fish. However, survival rates of lake trout from the Clay Banks refuge appeared to meet the minimum rate believed necessary for restoration of this species in Lake Michigan. Furthermore, adult survival rates have been increasing in recent years, and lake trout restoration in Lake Michigan is not hampered by low survival of adult fish. We hypothesize that the recent decrease in abundance of adult lake trout is primarily due to decreases in survival rates of lake trout younger than 6 years.

  7. Effects of Simulated Nitrogen Deposition on Soil Respiration in a Populus euphratica Community in the Ebinur Lake Area, a Desert Ecosystem of Northwestern China.

    PubMed

    He, Xuemin; Lv, Guanghui; Qin, Lu; Chang, Shunli; Yang, Min; Yang, Jianjun; Yang, Xiaodong

    2015-01-01

    One of the primary limiting factors for biological activities in desert ecosystems is nitrogen (N). This study therefore examined the effects of N and investigated the responses of an arid ecosystem to global change. We selected the typical desert plant Populus euphratica in a desert ecosystem in the Ebinur Lake area to evaluate the effects of N deposition on desert soil respiration. Three levels of N deposition (0, 37.5 and 112.5 kg·N·ha-1·yr-1) were randomly artificially provided to simulate natural N deposition. Changes in the soil respiration rates were measured from July to September in both 2010 and 2013, after N deposition in April 2010. The different levels of N deposition affected the total soil N, soil organic matter, soil C/N ratio, microorganism number, and microbial community structure and function. However, variable effects were observed over time in relation to changes in the magnitude of N deposition. Simulated high N deposition significantly reduced the soil respiration rate by approximately 23.6±2.5% (P<0.05), whereas low N deposition significantly increased the soil respiration rate by approximately 66.7±2.7% (P<0.05). These differences were clearer in the final growth stage (September). The different levels of N deposition had little effect on soil moisture, whereas N deposition significantly increased the soil temperature in the 0-5 cm layer (P<0.05). These results suggest that in the desert ecosystem of the Ebinur Lake area, N deposition indirectly changes the soil respiration rate by altering soil properties. PMID:26379186

  8. Effects of Simulated Nitrogen Deposition on Soil Respiration in a Populus euphratica Community in the Ebinur Lake Area, a Desert Ecosystem of Northwestern China

    PubMed Central

    He, Xuemin; Lv, Guanghui; Qin, Lu; Chang, Shunli; Yang, Min; Yang, Jianjun; Yang, Xiaodong

    2015-01-01

    One of the primary limiting factors for biological activities in desert ecosystems is nitrogen (N). This study therefore examined the effects of N and investigated the responses of an arid ecosystem to global change. We selected the typical desert plant Populus euphratica in a desert ecosystem in the Ebinur Lake area to evaluate the effects of N deposition on desert soil respiration. Three levels of N deposition (0, 37.5 and 112.5 kg·N·ha-1·yr-1) were randomly artificially provided to simulate natural N deposition. Changes in the soil respiration rates were measured from July to September in both 2010 and 2013, after N deposition in April 2010. The different levels of N deposition affected the total soil N, soil organic matter, soil C/N ratio, microorganism number, and microbial community structure and function. However, variable effects were observed over time in relation to changes in the magnitude of N deposition. Simulated high N deposition significantly reduced the soil respiration rate by approximately 23.6±2.5% (P<0.05), whereas low N deposition significantly increased the soil respiration rate by approximately 66.7±2.7% (P<0.05). These differences were clearer in the final growth stage (September). The different levels of N deposition had little effect on soil moisture, whereas N deposition significantly increased the soil temperature in the 0–5 cm layer (P<0.05). These results suggest that in the desert ecosystem of the Ebinur Lake area, N deposition indirectly changes the soil respiration rate by altering soil properties. PMID:26379186

  9. Hydrogeological features conditioning trophic levels of quarry lakes in western Po plain (north-western Italy)

    NASA Astrophysics Data System (ADS)

    De Luca, Domenico Antonio; Castagna, Sara; Lasagna, Manuela

    2013-04-01

    Quarry lakes occur in plains areas due to the extraction of alluvial sand and gravel used for grout and concrete in the construction industry. Excavation depths can reach and intersect the groundwater surface, thus creating a lake. Because of the need to optimize efficiency, the number of active open pit mines has increased in recent years; consequently, the global number of pit lakes will increase in coming decades (Castendyk and Eary 2009; Klapper and Geller 2001; Castro and Moore 2000). Similar to natural lakes, pit lakes are subject to eutrophication process, both during and after quarrying activity; during mining activity, the eutrophic level is strongly controlled by the excavation method. In the Piedmont territory (north-western Italy) there are 70 active quarry lakes, corresponding to approximately 0.1% of the entire plain area. Quarry lakes, located primarily along the main rivers occur in alluvial deposits of the plain area and have average depths between 20 and 30 m (maximum of 60 m deep) and surface areas between 3 and 30 hectares (Castagna 2008). The present study describes the trophic status of 23 active quarry lakes in the Piedmont plain that were evaluated by applying classifications from scientific literature. Currently, the majority of the studied quarry lakes may be defined as mesotrophic or eutrophic according to the trophic state classifications. Based on historic data, lake trophic levels have increased over time, during active mining. At the end of mining activity, further deterioration of water quality was expected, especially for smaller lakes with minimal oxygen stratification and higher levels of nutrients and algal growth. In addition, the paper focuses on the pit lake water quality and pit dimension; From an environmental perspective the excavation of quarry lakes with an appreciable size will likely result in a better safeguard of water quality and enhanced possibilities for lake end use after the cessation of mining. Piedmont quarry

  10. Repeated glacial lake outburst flood threatening the oldest Buddhist monastery in north-western Nepal

    NASA Astrophysics Data System (ADS)

    Kropáček, J.; Neckel, N.; Tyrna, B.; Holzer, N.; Hovden, A.; Gourmelen, N.; Schneider, C.; Buchroithner, M.; Hochschild, V.

    2015-10-01

    Since 2004, Halji village, home of the oldest Buddhist Monastery in north-western Nepal, has suffered from recurrent glacial lake outburst floods (GLOFs). A sudden englacial drainage of a supraglacial lake, located at a distance of 6.5 km from the village, was identified as the source of the flood. The topography of the lake basin was mapped by combining differential Global Positioning System (DGPS) measurements with a structure-from-motion (SFM) approach using terrestrial photographs. From this model the maximum filling capacity of the lake has been estimated as 1.06 ×106 m3 with a maximum discharge of 77.8 m3 s-1, calculated using the empiric Clague-Mathews formula. A simulation of the flooded area employing a raster-based hydraulic model considering six scenarios of discharge volume and surface roughness did not result in a flooding of the village. However, both the village and the monastery are threatened by undercutting of the river bank formed by unconsolidated sediments, as it already happened in 2011. Further, the comparison of the GLOF occurrences with temperature and precipitation from the High Asia Reanalysis (HAR) data set for the period 2001-2011 suggests that the GLOF is climate-driven rather than generated by an extreme precipitation event. The calculation of geodetic mass balance and the analysis of satellite images showed a rapid thinning and retreat of Halji Glacier which will eventually lead to a decline of the lake basin. As the basin will persist for at least several years, effective mitigation measures should be considered. A further reinforcement of the gabion walls was suggested as an artificial lake drainage is not feasible given the difficult accessibility of the glacier.

  11. Holocene tephra stratigraphy in four lakes in southeastern Oregon and northwestern Nevada, USA

    NASA Astrophysics Data System (ADS)

    Foit, Franklin F.; Mehringer, Peter J.

    2016-03-01

    To better understand the regional tephra stratigraphy and chronology of northern Nevada and southern Oregon, tephras in archived cores, taken as part of the Steens Mountain Prehistory Project from four lakes, Diamond Pond, Fish and Wildhorse lakes in southeastern Oregon and Blue Lake in northwestern Nevada, were reexamined using more advanced electron microprobe analytical technology. The best preserved and most complete core from Fish Lake along with Wildhorse Lake hosted two tephras from Mt. Mazama (Llao Rock and the Climactic Mazama), a mid-Holocene basaltic tephra from Diamond Craters, Oregon, two Medicine Lake tephras and an unexpected late Holocene Chaos Crags (Mt. Lassen volcanic center) tephra which was also found in the other lakes. Blue Lake was the only lake that hosted a Devils Hill tephra from the Three Sisters volcano in west central Oregon. Another tephra from the Three Sisters Volcano previously reported in sediments of Twin Lakes in NE Oregon, has now been confirmed as Rock Mesa tephra. The Chaos Crags, Devils Hill and Rock Mesa tephras are important late Holocene stratigraphic markers for central and eastern Oregon and northwestern Nevada.

  12. Summit Lake landslide and geomorphic history of Summit Lake basin, northwestern Nevada

    USGS Publications Warehouse

    Curry, B. Brandon; Melhorn, W.N.

    1990-01-01

    The Summit Lake landslide, northwestern Nevada, composed of Early Miocene pyroclastic debris, Ashdown Tuff, and basalt and rhyolite of the Black Rock Range, blocked the upper Soldier Creek-Snow Creek drainage and impounded Summit Lake sometimes prior to 7840 yr B.P. The slide covers 8.2 km2 and has geomorphic features characteristic of long run-out landslides, such as lobate form, longitudinal and transverse ridges, low surface gradient (7.1 ??), and preservation of original stratigraphic position of transported blocks. However, estimated debris volume is the smallest reported (2.5 ?? 105 m3) for a landslide of this type. The outflow channel of the Summit Lake basin was a northward-flowing stream valley entrenched by Mahogany Creek. Subsequent negative tectonic adjustment of the basin by about 35 m, accompanied by concommitant progradation of a prominent alluvial fan deposited by Mahogany Creek, argues for a probable diversion of drainage from the Alvord basin southward into the Lahontan basin. The landslide occurred while the creek flowed southward, transferring about 147 km2 of watershed from the Lahontan basin back to the Alvord basin. Overflow northward occurred during high stands of Pluvial Lake Parman in the basin; otherwise, under drier climates, the Summit Lake basin has been closed. Within large depressions on the slide surface, the ca. 6800 yr old Mazama Bed and other sediments have buried a weakly developed soil. Disseminated humus in the soil yields an age of 7840 ?? 310 yr B.P. Absence of older tephra (such as St. Helens M) brackets the slide age between 7840 and 19,000 yr B.P. Projectile points found on the highest strandlines of Pluvial Lake Parman suggest a ca 8700 yr B.P. age by correlation with cultural artifacts and radiocarbon ages from nearby Last Supper Cave, Nevada. Organic matter accumulation in landslide soils suggests ages ranging from 9100 to 16,250 yr B.P. Estimation of the age of the slide from morphologic data for the isolated Summit

  13. Geology of the lower Yellow Creek Area, Northwestern Colorado

    SciTech Connect

    Hail, W.J.

    1990-01-01

    The lower Yellow Creek area is located in Rio Blanco and Moffat Counties of northwestern Colorado, about midway between the towns of Rangely and Meeker. The study area is in the northwestern part of the Piceance Creek basin, a very deep structural and sedimentary basin that formed during the Laramide orogeny. Potentially important resources in the area are oil shale and related minerals, oil and gas, coal, and uranium. Topics discussed in the report include: Stratigraphy (Subsurface rocks, Cretaceous rocks, Tertiary rocks, and Quaternary deposits); Structure (Midland anticline, graben at Pinyon Ridge, and Crooked Wash syncline, Folds and faults in the vicinity of the White River, Red Wash syncline and central graben zone, Yellow Creek anticlinal nose); Economic geology (Oil shale and associated minerals, Coal, Oil and gas, Uranium, Gravel).

  14. 41. SOUTHEAST ACROSS WOODWORKING SHOP AREA IN NORTHWESTERN QUADRANT OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    41. SOUTHEAST ACROSS WOODWORKING SHOP AREA IN NORTHWESTERN QUADRANT OF FACTORY SHOWING ON LEFT CIRCA 1900 CROSS-CUTOFF CIRCULAR SAW AND ON RIGHT CIRCA 1900 TABLE SAW. BEHIND THE CROSS-CUTOFF SAW IS A CIRCA 1900 SNAG GRINDER. IN THE CENTER BACKGROUND IS THE CIRCA 1900 MICHIGAN MACHINERY MFG. CO. PUNCH PRESS. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  15. Dinkey Lakes Roadless Area, California

    SciTech Connect

    Dodge, F.C.W.; Federspiel, F.E.

    1984-01-01

    The results of a mineral survey conducted in 1980, show that parts of the Dinkey Lakes Roadless Area have substantiated resource potential for tungsten and marble and probable resource potential for quartz crystal gemstones. A probable resource potential for geothermal energy exists in one small area. No potential for other metallic mineral or energy resources was identified in this study.

  16. VITELLOGENIN GENE EXPRESSION IN FATHEAD MINNOWS AND PEARL DACE FROM CONTROL (NON-DOSED) AND LAKES DOSED WITH EE2 IN THE CANADIAN EXPERIMENTAL LAKES AREA

    EPA Science Inventory

    A whole-lake endocrine disruption experiment was conducted by Fisheries and Oceans Canada at the Experimental Lakes Area (ELA) in northwestern Ontario for three years beginning in 2001. This experiment examined population, organismal, biochemical and cellular-level effects in la...

  17. 40. NORTH ACROSS WOODWORKING AREA IN NORTHWESTERN QUADRANT OF FACTORY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. NORTH ACROSS WOODWORKING AREA IN NORTHWESTERN QUADRANT OF FACTORY ACROSS STACKED LUMBER ON SAWHORSES TOWARD CIRCA 1900 THICKNESS PLANER, SHOP-MADE BELT GUARD, AND BELOW THE SKYLIGHT OVERHEAD LINE SHAFT, BELTS, AND PULLEYS. BEYOND THE LUMBER ON A WHEELED WORK STATION ARE CIRCA 1900 ROLLS FOR BENDING PROPER CURVATURE IN STEEL WINDMILL BLADES AND CIRCA 1900 BEADING MACHINE FOR FORMING CREASES IN THE EDGES OF SHEET METAL PARTS SUCH AS WHEEL BLADES. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  18. Water resources of the Red Lake Indian Reservation, northwestern Minnesota

    USGS Publications Warehouse

    Ruhl, J.F.

    1991-01-01

    The quality of ground water is suitable for drinking and other household uses, and the quality of the surface water generally meets U.S. Environmental Protection Agency criteria necessary for the maintenance of aquatic life. The major ions in both ground and surface water are calcium, magnesium, and bicarbonate. Lower and Upper Red Lakes are eutrophic to mesotrophic on the basis of their summer Secchi disk-transparency readings, which ranged from 2.6 to 8.2 feet. The concentration of total organic carbon in samples from Lower and Upper Red Lakes and four streams were below or, in the case of one stream, about equal to 30 milligrams per liter, which is indicative of water little affected by human activities. The sample with the highest organic carbon content was collected from a stream that drained peatlands, which were probably sources of organic matter in the runoff. The concentration of nitrite plus nitrate in samples collected from Lower and Upper Red Lakes in late summer was below 0.01 milligrams per liter, which is characteristic of water uncontaminated by animal wastes. Total phosphorus in these samples ranged from 0.01 to 0.02 milligrams per liter. Most of this phosphorus was in the particulate organic fraction because of the abundance of phytoplankton.

  19. Distribution and seasonal dynamics of arsenic in a shallow lake in northwestern New Jersey, USA

    USGS Publications Warehouse

    Barringer, J.L.; Szabo, Z.; Wilson, T.P.; Bonin, J.L.; Kratzer, T.; Cenno, K.; Romagna, T.; Alebus, M.; Hirst, B.

    2011-01-01

    Elevated concentrations of arsenic (As) occurred during warm months in water from the outlet of Lake Mohawk in northwestern New Jersey. The shallow manmade lake is surrounded by residential development and used for recreation. Eutrophic conditions are addressed by alum and copper sulfate applications and aerators operating in the summer. In September 2005, arsenite was dominant in hypoxic to anoxic bottom water. Filterable As concentrations were about 1.6-2 times higher than those in the upper water column (23-25 ??g/L, mostly arsenate). Hypoxic/anoxic and near-neutral bottom conditions formed during the summer, but became more oxic and alkaline as winter approached. Acid-leachable As concentrations in lake-bed sediments ranged up to 694 mg/kg in highly organic material from the tops of sediment cores but were <15 mg/kg in geologic substrate. During warm months, reduced As from the sediment diffuses into the water column and is oxidized; mixing by aerators, wind, and boat traffic spreads arsenate and metals, some in particulate form, throughout the water column. Similar levels of As in sediments of lakes treated with arsenic pesticides indicate that most of the As in Lake Mohawk probably derives from past use of arsenical pesticides, although records of applications are lacking. The annual loss of As at the lake outlet is only about 0.01% of the As calculated to be in the sediments, indicating that elevated levels of As in the lake will persist for decades. ?? 2010 US Government.

  20. Investigation of the dramatic changes in lake level of the Bosten Lake in northwestern China

    NASA Astrophysics Data System (ADS)

    Guo, Mengjing; Wu, Wei; Zhou, Xiaode; Chen, Yongmin; Li, Jing

    2015-01-01

    Bosten Lake, located in the arid region of northwest China, is the largest inland freshwater lake in China. Water resources in Bosten Lake are of great importance for the regional drinking water supply, agricultural irrigation, and economic development of Xinjiang province. In this study, the dynamics of the lake level in Bosten Lake were investigated from 1956 to 2010. We found that the lake level experienced three different periods of change due to the combined influences of climate variation and human activities. Generally, the lake level has shown a significant downward trend since the first observation started in 1956 and dropped to its lowest level in 1987. Thereafter, the lake level presented a continuous upward trend and rose to its highest value in 2002. Then, the level decreased dramatically from 2002 to 2010. A water balance model and the climate elasticity method were used to estimate the reasons for the lake level changes of Bosten Lake. The results showed that an increase in lake evaporation led to the continuous decrease in lake level from 1958 to 1987. Then, human-controlled lake outflow and increasing lake inflow together led to the increase in lake level from 1988 to 2002. During 2003 to 2010, the emergency project of transferring water to Tarim River led to the increase in lake outflow, while the lake inflow obviously decreased because of a decrease in precipitation. These factors resulted in a sharp decrease in the lake level from 2003 to 2010. The changes in lake level indicate changes in available water resources from Bosten Lake. This reason for the analysis of the change in lake level in this study is to support the water resources management of Bosten Lake.

  1. Monitoring of a recurring glacial lake outburst flood in north-western Nepal

    NASA Astrophysics Data System (ADS)

    Neckel, Niklas; Kropacek, Jan; Schröter, Benjamin; Tyrna, Bernd; Buchroithner, Manfred

    2014-05-01

    Since 2004 an almost annual recurring glacial lake outburst flood threatens Halji Village, located in Limi valley in one of the most remote regions of north-western Nepal. So far a considerable extent of rare fields and several houses have been destroyed. A cultural heritage site, the Halji Monastery which is the oldest Buddhist monastery in western Nepal is located only 30 m from the flood path. A supra-glacial lake at an altitude of 5300 m a.s.l. located approximately 6 km away from the village was identified as the source of the flood from recent satellite imagery. In November/December 2013 we carried out a field survey in this region in order to understand the drainage paths of the lake, to measure the volume of the glacial lake and to set up an Automatic Weather Station (AWS). To assess both the filling and draining of the glacial lake a terrestrial time-lapse camera was installed taking six photographs every day. These show the glacial lake and parts of the feeding water channels. The images combined with the AWS data will help us to understand the dependency of magnitude and timing of the outburst event to the temperature, snow conditions and glacier movements. The collected data will also help us to learn more about the flooding event and serve as the input for a two dimensional hydrodynamic model which simulates the flood extent under different flooding scenarios.

  2. Late quaternary vegetational change in the Kotzebue sound area, northwestern Alaska

    SciTech Connect

    Anderson, P.M.

    1985-01-01

    Two sediment cores from Kaiyak and Squirrel lakes in northwestern Alaska yielded pollen records that date to ca. 39,000 and 27,000 yr B.P., respectively. Between 39,000 and 14,000 yr B.P., the vegetation around these lakes was dominated by Gramineae and Cyperaceae with some Salix and possibly Betula nana/glandulosa forming a local, shrub component of the vegetation. Betula pollen percentages increased about 14,000 yr B.P., indicating the presence of a birch-dominated shrub tundra. Alnus pollen appeared at both sites between 9000 and 8000 yr B.P., and Picea pollen (mostly P. mariana) arrived at Squirrel Lake about 5000 yr B.P. The current forest-tundra mosaic around Squirrel Lake was established at this time, whereas shrub tundra existed near Kaiyak Lake throughout the Holocene. When compared to other pollen records from northwestern North America, these cores (1) represent a meadow component of lowland, Beringian tundra between 39,000 and 14,000 yr B.P., (2) demonstrate an early Holocene arrival of Alnus in northwestern Alaska that predates most other Alnus horizons in northern Alaska or northwestern Canada, and (3) show an east-to-west migration of Picea across northern Alaska from 9000 to 5000 yr B.P.

  3. Geology of the lower Yellow Creek area, northwestern Colorado

    SciTech Connect

    Hail, W.J. Jr.

    1990-01-01

    The geology and resources of the lower Yellow Creek area, an area at the northwestern margin of the Piceance Creek basin comprising of four 7.5-minute quadrangles, are described. Subsurface face rocks penetrated by drill holes range in age from Pennsylvania to Cretaceous. Measured sections show the Mancos Shale and the Castlegate Sandstone, Iles Formation, and Williams Fork Formation of the Mesaverde Group of Late Cretaceous age and the Fort Union, Wasatch, Green River, and Uinta formations of Tertiary age. Surficial deposits of Quaternary age include terrace gravels, alluvium, and landslides. Fold axes and faults in the area trend northwesterly. The southern part of the area contains major oil-shale resources. Coal-bearing zones in the Williams Fork and Iles formations contain considerable coal. The coal-resources potential is limited, however, by nonpersistence of the thicker coal beds. Small amounts of gas have been produced from shallow, lenticular Tertiary sandstones. Large, but very lowgrade uranium resources are present in the Fort Union Formation.

  4. Hydrogeologic framework of the Maku area basalts, northwestern Iran

    NASA Astrophysics Data System (ADS)

    Asghari Moghaddam, Asghar; Fijani, Elham

    2009-06-01

    The Maku area in northwestern Iran is characterized by young lava flows which erupted from Mount Ararat in Turkey. These fractured volcanic rocks overlie alluvium associated with pre-existing rivers and form a good basalt-alluvium aquifer over an area of 650 km2. Groundwater discharge occurs from 12 large springs, ranging from 20 to 4,000 L s-1, and from some extraction wells. Permian and Oligo-Miocene age limestones along the northern boundary of the Bazargan and Poldasht Plains basalts are intensively karstified and groundwater from these high lands easily enters the basalt-alluvium aquifers. The transmissivity of the basalt-alluvium aquifer ranges from 24 to 870 m2 d-1, indicating heterogeneity. Groundwater of the aquifer is a sodium-bicarbonate and mixed cation-bicarbonate type and the concentration of fluoride is higher than the universal maximum admissible concentrations for drinking. In order to determine the chemical composition and identify the source of the high fluoride concentrations in the groundwater of the basaltic area, water samples from the springs, wells and rivers were analyzed. The results indicate that the high fluoride water enters the study area from the Sari Su River.

  5. New exposure ages for the Last Glacial Cycle in the Sanabria Lake region (northwestern Spain)

    NASA Astrophysics Data System (ADS)

    Rodríguez-Rodríguez, Laura; Jiménez-Sánchez, Montserrat; Domínguez-Cuesta, María Jose; Rinterknecht, Vincent; Pallàs, Raimon; Braucher, Régis; Bourlès, Didier; Valero-Garcés, Blas

    2013-04-01

    The Sanabria Lake region is located in the Trevinca Massif, a mid-latitude mountain area up to 2128 m asl in the northwest corner of the Iberian Peninsula (42oN 6oW). An ice cap glaciation took place during the Last Glacial Cycle in this massif, with an equilibrium line altitude of 1687 m for the Tera glacial outlet at its local maximum (Cowton et al., 2009). A well preserved glacial sequence occurs on an area of 45 km2 around the present Sanabria Lake (1000 m asl) and is composed by lateral and end moraines in close relationship with glaciolacustrine deposits. This sequence shows the ice snout oscillations of the former Tera glacier during the Last Glacial Cycle and offers a good opportunity to compare radiocarbon and OSL- based chronological models with new cosmogenic isotope dates. The new dataset of 10Be exposure ages presented here for the Sanabria Lake moraines is based on measurements conducted on 23 boulders and is compared with previous radiocarbon and OSL data conducted on ice related deposits (Pérez-Alberti et al., 2011; Rodríguez-Rodríguez et al., 2011). Our results are coherent with the available deglaciation radiocarbon chronology, and support a last deglaciation origin for the whole set of end moraines that are downstream the Sanabria Lake (19.2 - 15.7 10Be ka). Discrepancies between results of the different dating methods concern the timing of the local glacial maximum, with the cosmogenic exposure method always yielding the youngest minimum ages. As proposed to explain similar observations made elsewhere (Palacios et al., 2012), reconciling the ages from different dating methods would imply the occurrence of two glacial advances close enough in extent to generate an overlapping polygenic moraine. Cowton, T., Hughes, P.D., Gibbard, P.L., 2009. Palaeoglaciation of Parque Natural Lago de Sanabria, northwest Spain. Geomorphology 108, 282-291. Rodríguez-Rodríguez, L., Jiménez-Sánchez, M., Domínguez-Cuesta, M.J., Rico, M.T., Valero-Garcés, B

  6. Infection of Myxobolus galaxii (Myxozoa) in Galaxias maculatus (Osmeriformes: Galaxiidae) from northwestern Patagonian Andean lakes (Argentina).

    PubMed

    Flores, Verónica; Viozzi, Gustavo

    2007-04-01

    The infection of Myxobolus galaxii Szidat, 1953, from the musculature and abdominal organs of northwestern Patagonian Galaxias maculatus is described. Plasmodia are histozoic and intercellular. Spores are pyriform in valvar view and biconvex in sutural view, with 4-9 edge notches in the sutural line, varying in shape within the same plasmodium. Myxobolus galaxii was detected in fish from 7 of 17 Andean Patagonian lakes, with prevalences ranging between 2 and 17%. A repeating pattern of summer increment in prevalence was observed, which could be explained by the ontogenetic migratory movements of the fish in Lake Gutiérrez. Also, accumulation of plasmodia through the life span of fish was detected. PMID:17539428

  7. Impacts of climate and humans on the vegetation in northwestern Turkey: palynological insights from Lake Iznik since the Last Glacial

    NASA Astrophysics Data System (ADS)

    Miebach, Andrea; Niestrath, Phoebe; Roeser, Patricia; Litt, Thomas

    2016-03-01

    The Marmara region in northwestern Turkey provides a unique opportunity for studying the vegetation history in response to climate changes and anthropogenic impacts because of its location between different climate and vegetation zones and its long settlement history. Geochemical and mineralogical investigations of the largest lake in the region, Lake Iznik, already registered climate-related changes of the lake level and the lake mixing. However, a palynological investigation encompassing the Late Pleistocene to Middle Holocene was still missing. Here, we present the first pollen record of the last ca. 31 ka cal BP (calibrated kilo years before 1950) inferred from Lake Iznik sediments as an independent proxy for paleoecological reconstructions. Our study reveals that the vegetation in the Iznik area changed generally between (a) steppe during glacials and stadials indicating dry and cold climatic conditions, (b) forest-steppe during interstadials indicating milder and moister climatic conditions, and (c) oak-dominated mesic forest during interglacials indicating warm and moist climatic conditions. Moreover, a pronounced succession of pioneer trees, cold temperate, warm temperate, and Mediterranean trees appeared since the Lateglacial. Rapid climate changes, which are reflected by vegetation changes, can be correlated with Dansgaard-Oeschger (DO) events such as DO-4, DO-3, and DO-1, the Younger Dryas, and probably also the 8.2 event. Since the mid-Holocene, the vegetation was influenced by anthropogenic activities. During early settlement phases, the distinction between climate-induced and human-induced changes of the vegetation is challenging. Still, evidence for human activities consolidates since the Early Bronze Age (ca. 4.8 ka cal BP): cultivated trees, crops, and secondary human indicator taxa appeared, and forests were cleared. Subsequent fluctuations between extensive agricultural uses and regenerations of the natural vegetation become apparent.

  8. Lake-level Fluctuation and Climate Cyclicity Observed in Lake Strata in the Northwestern Qaidam Basin, China

    NASA Astrophysics Data System (ADS)

    Riegel, H. B.; Heermance, R. V., III; Nie, J.; Su, Q.; Garzione, C. N.

    2015-12-01

    The Pliocene and Quaternary are times of rapid, extreme climate variability, but 3-D geologic exposures of lacustrine strata from this time are rare, impeding observations of the impact of climate-change on lake sedimentation. The Qaidam Basin (QB) in western China provides a unique geologic setting, where internally drained lakes have existed for the past few million years, and recent deformation of the basin floor has uplifted and exposed lacustrine strata. This stratigraphy records a detailed history of lake level fluctuation, evaporite deposition, and climate change. We provide new paleomagnetic, δ18O and δ13C data combined with detailed sedimentology from the lower 475 m of a 900 m thick stratigraphic section (38.28N, 91.54E) in the northwestern QB to reveal a high-resolution record of sedimentation and climate change during the Plio-Quaternary. 12 magnetozones indicate an age for the lower half of the section between 6.0-3.0 Ma. The section consists of 9 lithofacies (1 mudstone, 4 sandstone, 1 conglomerate, 2 gypsum, 1 halite) that can be divided into 3 stratigraphic units based on evaporite concentration. Alternating mud, gypsum, and halite beds imply multiple lake-level fluctuations and occasional complete drying of the lake. This is consistent with >12.5‰ variation in the δ18O values of lacustrine carbonates (δ18Oc), indicating large-scale lake level fluctuation below 410 m, consistent with the boundary of Unit 1 and 2. Between 410 and 475 m, the δ18Oc values are ~-5 ‰. Above 475 m, an increase in gypsum concentration causes a thick salt-crust to develop on the outcrop, making sampling impossible. This stratigraphic level corresponds to an age of ~3.0 Ma, when the QB became hyper-arid. The presence of gypsum and halite throughout the section implies that the QB was arid and internally drained by at least 6 Ma, although the basin may have been divided into multiple lakes based on the bimodal δ18O values from different parts of the QB during that

  9. Distribution and seasonal dynamics of arsenic in a shallow lake in northwestern New Jersey, USA.

    PubMed

    Barringer, Julia L; Szabo, Zoltan; Wilson, Timothy P; Bonin, Jennifer L; Kratzer, Todd; Cenno, Kimberly; Romagna, Terri; Alebus, Marzooq; Hirst, Barbara

    2011-02-01

    Elevated concentrations of arsenic (As) occurred during warm months in water from the outlet of Lake Mohawk in northwestern New Jersey. The shallow manmade lake is surrounded by residential development and used for recreation. Eutrophic conditions are addressed by alum and copper sulfate applications and aerators operating in the summer. In September 2005, arsenite was dominant in hypoxic to anoxic bottom water. Filterable As concentrations were about 1.6-2 times higher than those in the upper water column (23-25 μg/L, mostly arsenate). Hypoxic/anoxic and near-neutral bottom conditions formed during the summer, but became more oxic and alkaline as winter approached. Acid-leachable As concentrations in lake-bed sediments ranged up to 694 mg/kg in highly organic material from the tops of sediment cores but were <15 mg/kg in geologic substrate. During warm months, reduced As from the sediment diffuses into the water column and is oxidized; mixing by aerators, wind, and boat traffic spreads arsenate and metals, some in particulate form, throughout the water column. Similar levels of As in sediments of lakes treated with arsenic pesticides indicate that most of the As in Lake Mohawk probably derives from past use of arsenical pesticides, although records of applications are lacking. The annual loss of As at the lake outlet is only about 0.01% of the As calculated to be in the sediments, indicating that elevated levels of As in the lake will persist for decades. PMID:20405171

  10. An evaluation of lake trout reproductive habitat on Clay Banks Reef, northwestern Lake Michigan

    USGS Publications Warehouse

    Edsall, Thomas A.; Holey, Mark E.; Manny, Bruce A.; Kennedy, Gregory W.

    1995-01-01

    The extinction of the native populations of lake trout (Salvelinus namaycush) in Lake Michigan in about 1956 has been followed by a decades-long attempt to reestablish self-sustaining populations of this valuable species in habitats it formerly occupied throughout the lake. One of the most recent management strategies designed to facilitate recovery was to make a primary management objective the establishment of sanctuaries where stocked lake trout could be protected and self-sustaining populations reestablished. In the present study we employed habitat survey and mapping techniques, field and laboratory bioassays, egg traps, sediment traps, and gill nets to examine the potential for successful natural reproduction by stocked lake trout on Clay Banks Reef in the Door-Kewaunee sanctuary in Wisconsin waters of Lake Michigan. Our study revealed (1) there was suitable habitat on the reef to support the production of viable fry, (2) spawner abundance on the reef was the highest recorded in the great lakes, and (3) eggs taken from spawners on the reef and held on the reef in plexiglas incubators hatched and produced fry that survived through swim-up. We conclude that Clay Banks Reef has the potential to support successful natural reproduction by stocked lake trout.

  11. Microbial Diversity in Water and Sediment of Lake Chaka, an Athalassohaline Lake in Northwestern China

    PubMed Central

    Jiang, Hongchen; Dong, Hailiang; Zhang, Gengxin; Yu, Bingsong; Chapman, Leah R.; Fields, Matthew W.

    2006-01-01

    We employed culture-dependent and -independent techniques to study microbial diversity in Lake Chaka, a unique hypersaline lake (32.5% salinity) in northwest China. It is situated at 3,214 m above sea level in a dry climate. The average water depth is 2 to 3 cm. Halophilic isolates were obtained from the lake water, and halotolerant isolates were obtained from the shallow sediment. The isolates exhibited resistance to UV and gamma radiation. Microbial abundance in the sediments ranged from 108 cells/g at the water-sediment interface to 107 cells/g at a sediment depth of 42 cm. A major change in the bacterial community composition was observed across the interface. In the lake water, clone sequences affiliated with the Bacteroidetes were the most abundant, whereas in the sediments, sequences related to low G+C gram-positive bacteria were predominant. A similar change was also present in the archaeal community. While all archaeal clone sequences in the lake water belonged to the Halobacteriales, the majority of the sequences in the sediments were related to those previously obtained from methanogenic soils and sediments. The observed changes in the microbial community structure across the water-sediment interface were correlated with a decrease in salinity from the lake water (32.5%) to the sediments (approximately 4%). Across the interface, the redox state also changed from oxic to anoxic and may also have contributed to the observed shift in the microbial community. PMID:16751487

  12. Carbon and oxygen isotopic records from Lake Tuosu over the last 120 years in the Qaidam Basin, Northwestern China: The implications for paleoenvironmental reconstruction

    NASA Astrophysics Data System (ADS)

    Li, Xiangzhong; Zhou, Xin; Liu, Weiguo; Wang, Zheng; He, Yuxin; Xu, Liming

    2016-06-01

    Isotopic compositions of total organic carbon (TOC) and authigenic carbonate in lakes have been widely used to reconstruct paleoclimatic changes and the depositional environments of lake sediments. However, since these proxies are often controlled by multiple environmental factors, detailed examinations of modern environmental processes is necessary before further applying them into paleoclimatic studies, especially in arid/semi-arid northwestern China. Here we generate High-resolution multi-proxy sedimentary records from Lake Tuosu, a hydrologically closed, saline and alkaline lake located at the north margin of the Qaidam Basin, through analysis of carbon isotope of TOC, and δ18O and δ13C values of ostracods over the last 120 years. Together with the meteorological data (precipitation and temperature), lake area record, and other tree-ring evidence, we examine how these sedimentary indices respond to changes in hydrologic balance and climate at interannual to decadal timescales. We found that sedimentary δ13Corg values resemble the variation of lake areas of Lake Tuosu over the last 40 years, suggesting that δ13Corg values would be an ideal indicator of lake area/level fluctuations and thus effective moisture variations (precipitation vs. evaporation). However, ostracod δ18O, which was previously used as proxies of effective precipitation, is not well correlated with δ13Corg values in Lake Tuosu. Therefore, the changes of ostracod δ18O values cannot be straightforwardly explained as the effective precipitation. Instead, the isotopic composition of carbonate would be additionally controlled by other factors including isotopic compositions of input water and drainage pattern.

  13. Holocene Environmental Change Recorded by the Mineral Magnetic Properties of Juyan Lake Sediments in Northwestern China

    NASA Astrophysics Data System (ADS)

    Jin, Ming; Zhao, Ruirui; Liu, Yuhang; Xia, Dunsheng

    2013-04-01

    The Holocene environmental change of Juyan region in northwestern China was studied by a combination of scientific methods including analyzing magnetic parameters, total organic carbon content (TOC), grain size and other environmental proxies of the core G36 in Juyan Lake, based on the precise AMS14C dating. Results show that most magnetic carrier minerals that appeared in coarse sediments and the main magnetic minerals are contained in multi-domain magnetite particles. Environmental proxies show that the Holocene environmental changes of Juyan Lake could be divided into four arid-wet alternating periods: arid period in 6700~4600 a BP, wet period in 4600~3100 a BP, arid period in 3100~2500 a BP, and the lake drying up period since 1800 a BP. In these four periods, two significant wet events and two outstanding arid events are recorded in magnetic parameters. The change mechanism of magnetic susceptibility is complicated and there is no simple positive or negative relationship between magnetic susceptibility change and environmental arid-wet change.

  14. Environmental monitoring and ecological risk assessment for pesticide contamination and effects in Lake Pamvotis, northwestern Greece.

    PubMed

    Hela, Dimitra G; Lambropoulou, Dimitra A; Konstantinou, Ioannis K; Albanis, Triantafyllos A

    2005-06-01

    Monitoring of pesticide residues in water and sediments was conducted as a basis for subsequent ecotoxicological risk assessment for the shallow eutrophic Lake Pamvotis, northwestern Greece. During a one-year study period, atrazine, desethylatrazine (DEA), simazine, diazinon, malathion, oxamyl, carbofuran, and ethion were detected in water and atrazine, desethylatrazine, diazinon, and s-ethyl dipropylthiocarbamate (EPTC) in sediments, all at ppb concentration level. Temporal variation in pesticide concentrations was observed. Highest residue levels for most pesticides in both water and sediment matrices occurred in the May to July period with the exception of atrazine and DEA, which show highest levels in water during the September to November period. The ecological risk associated with pesticide contamination was assessed using two different methods: The toxic unit method, which provides a first indication of the relative contribution of detected pesticides to the total toxicity and a probabilistic approach, and the inverse method of Van Straalen and Denneman, which is used to quantify the ecological risk. The maximum percentage of the ecological risk was 10.3 and 51.8% for water and 17.2 and 70.6% for sediment, based on acute and chronic level, respectively. These results show that pesticides exert a significant pressure on the aquatic system of Lake Pamvotis, especially for the chronic-effect level. Simple quotient methods should be coupled with higher-tier risk assessment, especially if restoration activities on lake ecosystems are to be undertaken for sustainable development. PMID:16117136

  15. Additions of nutrients and major ions by the atmosphere and tributaries to nearshore waters of northwestern Lake Huron

    USGS Publications Warehouse

    Manny, Bruce A.; Owens, R.W.

    1983-01-01

    Nutrient additions by the atmosphere and six tributaries to nearshore waters of northwestern Lake Huron were measured at weekly intervals from August 1975 to July 1976. The atmosphere contributed 43% of the nitrogen (N) and 10% of the phosphorus (P) that was added during the year. The 1975–76 atmospheric loading rate of total N to this area (11 kg/ha/yr) was one of the highest found to date in the United States. N was conserved more efficiently than P in the tributary drainage basins. Of the N and P that fell annually on the watersheds under study, 2 to 37% of the N and 31 to 84% of the P was carried with runoff to the lake. From a basin where ditching and clear-cutting occurred, water, P, silica (SiO2), N, and sodium were lost at higher rates than from five other basins. Most of the N in bulk atmospheric samples (23%) and tributary waters (56%) was dissolved organic N, a form of N not often measured.

  16. Hydrogeology of the Lake Miona area, northeast Sumter County, Florida

    USGS Publications Warehouse

    Bradner, L.A.

    1986-01-01

    The Lake Miona area, in northeast Sumter County, is characterized by karstic depressions that contain lakes, ponds, and marshes that drain vertically to the upper Floridan aquifer. Lake Miona, Black Lake, and Cherry Lake are the prominent water features of the area. When the lake levels are lowest, the lakes are not connected, but at higher levels, they become connected and water flows eastward from Lake Miona through Black Lake to Cherry Lake. The chemical and biological conditions in the lakes are such that, although they support a large population of submerged aquatic plants, no problem with algae blooms was observed. (USGS)

  17. Physical and hydrochemical evidence of lake leakage near Jim Woodruff lock and dam and ground-water inflow to Lake Seminole, and an assessment of karst features in and near the lake, southwestern Georgia and northwestern Florida

    USGS Publications Warehouse

    Torak, Lynn J.; Crilley, Dianna M.; Painter, Jaime A.

    2006-01-01

    Hydrogeologic data and water-chemistry analyses indicate that Lake Seminole leaks into the Upper Floridan aquifer near Jim Woodruff Lock and Dam, southwestern Georgia and northwestern Florida, and that ground water enters Lake Seminole along upstream reaches of the lake's four impoundment arms (Chattahoochee and Flint Rivers, Spring Creek, and Fishpond Drain). Written accounts by U.S. Army Corps of Engineers geologists during dam construction in the late 1940s and early 1950s, and construction-era photographs, document karst-solution features in the limestone that comprise the lake bottom and foundation rock to the dam, and confirm the hydraulic connection of the lake and aquifer. More than 250 karst features having the potential to connect the lake and aquifer were identified from preimpoundment aerial photographs taken during construction. An interactive map containing a photomosaic of 53 photographic negatives was orthorectfied to digital images of 1:24,000-scale topographic maps to aid in identifying karst features that function or have the potential to function as locations of water exchange between Lake Seminole and the Upper Floridan aquifer. Some identified karst features coincide with locations of mapped springs, spring runs, and depressions that are consistent with sinkholes and sinkhole ponds. Hydrographic surveys using a multibeam echosounder (sonar) with sidescan sonar identified sinkholes in the lake bottom along the western lakeshore and in front of the dam. Dye-tracing experiments indicate that lake water enters these sinkholes and is transported through the Upper Floridan aquifer around the west side of the dam at velocities of about 500 feet per hour to locations where water 'boils up' on land (at Polk Lake Spring) and in the channel bottom of the Apalachicola River (at the 'River Boil'). Water discharging from Polk Lake Spring joins flow from a spring-fed ground-water discharge zone located downstream of the dam; the combined flow disappears into

  18. Multi-century lake area changes in the Southern Altiplano: a tree-ring-based reconstruction

    NASA Astrophysics Data System (ADS)

    Morales, M. S.; Carilla, J.; Grau, H. R.; Villalba, R.

    2015-09-01

    Size fluctuations in endorheic lakes in northwestern Argentina (NWA) and southwestern Bolivia (SWB) are very sensitive to basin hydrological balances, and consequently, very vulnerable to deleterious effects from climatic changes. The management of these water resources and their biodiversity requires a comprehensive knowledge of their natural variability over multiple timescales. In this study, we present a multi-century reconstruction of past lake-area fluctuations in NWA and SWB. The evidence used to develop and validate this reconstruction includes satellite images and a century-long tree-ring record from P. tarapacana. Inter-annual fluctuations in lake area of nine lakes were quantified based on Landsat satellite images over the period 1975 to 2009. A regional P. tarapacana tree-ring chronology, composite from two sampling sites, was used as predictors in a regression model to reconstruct the mean annual (January-December) lake area from the nine lakes. The reconstruction model captures 62 % of the total variance in lake-area fluctuations and shows adequate levels of cross-validation. This high-resolution reconstruction covers the past 601 years and characterizes the occurrence of annual to multi-decadal lake area fluctuations and its main oscillation modes of variability. Our reconstruction points out that the late 20th century decrease in lake area was exceptional over the period 1407-2007; a persistent negative trend in lake area is clear in the reconstruction and consistent with glacier retreat and other climate proxies from the Altiplano and the tropical Andes. Since the mid 1970s, the Vilama-Coruto lake system recorded an accelerated decrease in area consistent with an increasing recurrence of extremely small lake-area events. Throughout the 601 years, the reconstruction provides valuable information about spatial and temporal stabilities of the relationships between changes in lake area, ENSO, and PDO, highlighting the Pacific influence over most modes

  19. ALPINE LAKES WILDERNESS STUDY AREA, WASHINGTON.

    USGS Publications Warehouse

    Gualtieri, J.L.; Thurber, H.K.

    1984-01-01

    The Alpine Lakes Wilderness study area, located in the central part of the Cascade Mountains of Washington was examined for its mineral-resource potential. On the basis of that study the area was found to contain deposits of copper, other base metals, and gold and silver. Probable or substantiated mineral-resource potential exists for these commodities in the southwest-central, northwest, and southeast-central parts of the area. The geologic terrane precludes the occurrence of fossil fuel resources.

  20. Effect of power plant emission reductions on a nearby wilderness area: a case study in northwestern Colorado

    USGS Publications Warehouse

    Mast, M. Alisa; Ely, Daniel

    2013-01-01

    This study evaluates the effect of emission reductions at two coal-fired power plants in northwestern Colorado on a nearby wilderness area. Control equipment was installed at both plants during 1999–2004 to reduce SO2 and NOx emissions. One challenge was separating the effects of local from regional emissions, which also declined during the study period. The long-term datasets examined confirm that emission reductions had a beneficial effect on air and water quality in the wilderness. Despite a 75 % reduction in SO2 emissions, sulfate aerosols measured in the wilderness decreased by only 20 %. Because the site is relatively close to the power plants (2 to sulfate, particularly under conditions of low relative humidity, might account for this less than one-to-one response. On the clearest days, emissions controls appeared to improve visibility by about 1 deciview, which is a small but perceptible improvement. On the haziest days, however, there was little improvement perhaps reflecting the dominance of regional haze and other components of visibility degradation particularly organic carbon and dust. Sulfate and acidity in atmospheric deposition decreased by 50 % near the southern end of the wilderness of which 60 % was attributed to power plant controls and the remainder to reductions in regional sources. Lake water sulfate responded rapidly to trends in deposition declining at 28 lakes monitored in and near the wilderness. Although no change in the acid–base status was observed, few of the lakes appear to be at risk from chronic or episodic acidification.

  1. Hydrogeology of the Tully Lakes area in southern Onondaga and Cortland counties, New York

    USGS Publications Warehouse

    Kappel, William M.; Miller, Todd S.; Hetcher, Kari K.

    2001-01-01

    Glacial processes created the many kettlehole lakes, ponds, and depressions in the Tully Lakes area, as well as the Valley Heads Moraine, which forms the drainage divide between the St. Lawrence River drainage to the north and the Susquehanna River drainage to the south. The first hydrogeologic studies of the Tully Lakes area began in the 1870's, when the lakes were considered as a possible water supply for the city of Syracuse. Water was diverted from some of the northwestern lakes and ponds into the Tully Valley; these diversions occurred as early as the 1840's and ceased in the early 1960's, with the closure of the eastern Tully Valley brinefield. In 1998, the USGS began a 2-year hydrogeologic study of the aquifer system underlying the Tully Lakes area that included monitoring water levels in five of the Tully Lakes and more than 50 wells. The average annual water-level fluctuations in the three western lakes ranged from about 2.5 feet to 6 feet. Water-level fluctuations in the eastern lakes, near the center of the valley, were much less--about 1.5 feet, because these lakes have natural outlets. Three sets of ground-water-level measurements were made from the spring recharge period through the fall dry period of 2000. The resulting potentiometric-surface maps indicate that the water-level declines from the spring to the fall ranged from 1.5 to 8 feet. The ground-water divide is about 1 mile south of the Valley Heads Moraine crest in the spring and migrates southward in response to declining water levels in the surficial aquifer during the fall. Water-surface altitudes in the kettlehole lakes and ponds respond slowly to seasonal water-level changes in the surrounding aquifer and often differ from water levels in the aquifer because the poorly permeable lakebed sediments impede the exchange of water.

  2. Rainy Lake wrench zone: An example of an Archaean subprovince boundary in northwestern Ontario

    NASA Technical Reports Server (NTRS)

    Poulsen, K. H.

    1986-01-01

    The Superior Province of the Canadian Shield comprises an alternation of subprovinces with contrasting lithological, structural and metamorphic styles. Rocks of the Rainly Lake area form a fault bounded wedge between two of these subprovinces, the Wabigoon granite-greenstone terrain to the north and the Quetico metasedimentary terrain to the south. The Quetico and Seine River-Rainy Lake Faults bound this wedge within which interpretation of the stratigraphy has been historically contentious. In the eastern part of the wedge, volcanic rocks and coeval tonalitic sills are unconformably overlain by fluviatile conglomerate and arenite of the Seine Group; in the western part of the wedge, metamorphosed wacke and mudstone of the Coutchiching Group are cut by granodioritic plutons. The Coutchiching Group has previously been correlated with the Seine Group and with the turbiditic Quetico metasediments of the Quetico Subprovince and these correlations are the cornerstone of earlier tectonic models which relate the subprovinces. The structural geology of the Rainy Lake area is characterized by attributes which compare favourably with the known characteristics of dextral wrench or 'transpressive zones based both on experimental data and natural examples. Much of this deformation involved the Seine Group, the youngest stratigraphic unit in the area, and predates the emplacement of late-to-post-tectonic granodioritic plutons for which radiometric data indicate a Late Archean age.

  3. The effects of simulated solar UVB radiation on early developmental stages of the Northwestern Salamander (Ambystoma gracile) from three lakes

    USGS Publications Warehouse

    Calfee, Robin D.; Little, Edward E.; Pearl, Christopher A.; Hoffman, Robert L.

    2010-01-01

    Solar ultraviolet radiation (UV) has received much attention as a factor that could play a role in amphibian population declines. UV can be hazardous to some amphibians, but the resultant effects depend on a variety of environmental and behavioral factors. In this study, the potential effects of UV on the Northwestern Salamander, Ambystoma gracile, from three lakes were assessed in the laboratory using a solar simulator. We measured the survival of embryos and the survival and growth of larvae exposed to four UV treatments in controlled laboratory studies, the UV absorbance of egg jelly, oviposition depths in the lakes, and UV absorbance in water samples from the three lakes. Hatching success of embryos decreased in the higher UV treatments as compared to the control treatments, and growth of surviving larvae was significantly reduced in the higher UVB irradiance treatments. The egg jelly exhibited a small peak of absorbance within the UVB range (290–320 nm). The magnitude of UV absorbance differed among egg jellies from the three lakes. Oviposition depths at the three sites averaged 1.10 m below the water surface. Approximately 66% of surface UVB radiation was attenuated at 10-cm depth in all three lakes. Results of this study indicate that larvae may be sensitive to UVB exposure under laboratory conditions; however, in field conditions the depths of egg deposition in the lakes, absorbance of UV radiation by the water column, and the potential for behavioral adjustments may mitigate severe effects of UV radiation.

  4. 33 CFR 165.1301 - Puget Sound and Adjacent Waters in Northwestern Washington-Regulated Navigation Area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Puget Sound and Adjacent Waters... Areas Thirteenth Coast Guard District § 165.1301 Puget Sound and Adjacent Waters in Northwestern... northwestern Washington waters under the jurisdiction of the Captain of the Port, Puget Sound: Puget...

  5. 33 CFR 165.1301 - Puget Sound and Adjacent Waters in Northwestern Washington-Regulated Navigation Area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Puget Sound and Adjacent Waters... Areas Thirteenth Coast Guard District § 165.1301 Puget Sound and Adjacent Waters in Northwestern... northwestern Washington waters under the jurisdiction of the Captain of the Port, Puget Sound: Puget...

  6. 33 CFR 165.1301 - Puget Sound and Adjacent Waters in Northwestern Washington-Regulated Navigation Area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Puget Sound and Adjacent Waters... Areas Thirteenth Coast Guard District § 165.1301 Puget Sound and Adjacent Waters in Northwestern... northwestern Washington waters under the jurisdiction of the Captain of the Port, Puget Sound: Puget...

  7. 33 CFR 165.1301 - Puget Sound and Adjacent Waters in Northwestern Washington-Regulated Navigation Area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Puget Sound and Adjacent Waters... Areas Thirteenth Coast Guard District § 165.1301 Puget Sound and Adjacent Waters in Northwestern... northwestern Washington waters under the jurisdiction of the Captain of the Port, Puget Sound: Puget...

  8. Sensitivity to acidification of subalpine ponds and lakes in north-western Colorado

    NASA Astrophysics Data System (ADS)

    Campbell, D. H.; Muths, E.; Turk, J. T.; Corn, P. S.

    2004-10-01

    Although acidifying deposition in western North America is lower than in many parts of the world, many high-elevation ecosystems there are extremely sensitive to acidification. Previous studies determined that the Mount Zirkel Wilderness Area (MZWA) has the most acidic snowpack and aquatic ecosystems that are among the most sensitive in the region. In this study, spatial and temporal variability of ponds and lakes in and near the MZWA were examined to determine their sensitivity to acidification and the effects of acidic deposition during and after snowmelt. Within the areas identified as sensitive to acidification based on bedrock types, there was substantial variability in acid-neutralizing capacity (ANC), which was related to differences in hydrological flowpaths that control delivery of weathering products to surface waters. Geological and topographic maps were of limited use in predicting acid sensitivity because their spatial resolution was not fine enough to capture the variability of these attributes for lakes and ponds with small catchment areas. Many of the lakes are sensitive to acidification (summer and autumn ANC < 100 μeq L-1), but none of them appeared to be threatened immediately by episodic or chronic acidification. In contrast, 22 ponds had minimum ANC < 30 μeq L-1, indicating that they are extremely sensitive to acidic deposition and could be damaged by episodic acidification, although net acidity (ANC < 0) was not measured in any of the ponds during the study. The lowest measured pH value was 5.4, and pH generally remained less than 6.0 throughout early summer in the most sensitive ponds, indicating that biological effects of acidification are possible at levels of atmospheric deposition that occurred during the study. The aquatic chemistry of lakes was dominated by atmospheric deposition and biogeochemical processes in soils and shallow ground water, whereas the aquatic chemistry of ponds was also affected by organic acids and biogeochemical

  9. Do environmental differences between lakes in northwestern Argentinean Patagonia affect the infection of Philureter trigoniopsis (monogenea) in Galaxias maculatus (osmeriformes)?

    PubMed

    Viozzi, G P; Semenas, L G

    2009-02-01

    Philureter trigoniopsis is the only parasite found in the ureters and urinary bladder of Galaxias maculatus in Patagonian Andean lakes. The dynamics of this endoparasitic monogenean were studied in Lake Gutiérrez, a body of water with scarce shoreline vegetation, where the host has an annual cycle of migration to the deep pelagic zone of the lake. To compare variations of the infection related to differences between lakes, G. maculatus specimens were sampled monthly with baited traps from September 1998 to November 1999 in Lake Moreno, which is an oligotrophic body of water with emergent shoreline vegetation and where the fish do not migrate to the deep pelagic areas of the lake. In addition, data for summer infections of P. trigoniopsis from 10 Andean Patagonian lakes that differ in aquatic vegetation, depth, and area were compared. In Lake Moreno prevalence of P. trigoniopsis showed a seasonal pattern, with 1-yr-old fish exhibiting the highest values of prevalence and mean intensity. Negative correlations between water temperature and prevalence and between age of fish and abundance were found. Our results suggest that age of fish may be the main factor structuring the distribution of P. trigoniosis in populations of G. maculatus. At the regional level the relationship between the infection and the characteristics of the lakes was also observed, with prevalence and mean intensity of P. trigoniopsis in G. maculatus higher in large deep lakes without macrophytes. PMID:18576893

  10. First GNSS results in the Oran area (northwestern Algeria)

    NASA Astrophysics Data System (ADS)

    bougrine, amina; Nocquet, Jean-Mathieu; Yelles-Chaouche, Abdelkarim; Lammali, Kamel; Bacha, Wahab; Terki, Toufik

    2016-04-01

    Sparse results along northern Algeria are so far available to better understand how Nubia/Eurasia convergence is accommodated in the western Mediterranean and quantitatively assess seismic potential in that area. In this study, we show new GNSS results in the Tellian atlas in western Algeria. The studied area encompasses the Mleta basin bordered in the north by the Murdjadjo range, which is thought to be the locus of the large 1790 earthquake (estimated magnitude 7.5 Bouhadad, 2001). This area includes the city of Oran, the second most populated city of Algeria. The GNSS network includes 18 sites, spanning 180km East-West along the coast of Algeria and 40 km inland, with inter-site distance of 15 km. It has been observed in 2008, 2012 and 2013 for enabling velocity to be estimated at the 1 mm/yr. GNSS Data have been processed using GAMIT/GLOBK software, together with 04 permanent sites in Algeria and 87 IGS sites surrounding the area of study. Uncertainties on campaign results have been rescaled according to the analysis of the nearby CGPS time series. The recorded seismicity and the obtained GNSS velocity field from the three campaigns with a five years span, indicate that this region is tectonically active and subjected to significant horizontal motions. A regional NW displacement of 2-4mm/yr in the Eurasia stable reference frame is consistent with the expected Nubia-Eurasia motion. The obtained velocity field in the Nubian fixed reference frame gives a slow strain rate less than 2mm/yr representing the strain rate accommodated across the Murdjadjo range and the different features around the Mlena basin.

  11. Geology of the central Roan Plateau area, northwestern Colorado

    SciTech Connect

    Hail, W.J. Jr.

    1992-01-01

    The geology of the central Roam Plateau area in the south-central part of the Piceance Creek basin, comprising four 7.5-minute quadrangles, is described. Subsurface rocks penetrated by drill holes include the Mancos Shale and Mesaverde Formation of Later Cretaceous age, and parts of the Wasatch Formation of Paleocene and Eocene age, and Green River Formation of Eocene age. Exposed rocks, aggregating as much as 4,550 feet in thickness, are all Eocene in age and include the upper part of the Wasatch Formation , and the Green River and Uinta formations. The Green River and Uinta formations are extensively intertongued. Surficial deposits of Quaternary age include alluvium, talus, slopewash, and landslides. Two northwesterly trending folds, the Clear Creek Syncline and the Crystal Creek anticlinal nose, are present in the northern part of the area. There are no major faults. The area contains large potentially important oil-shale resources, mostly in the Parachute Creek member of the Green River Formation.

  12. 36 CFR 7.62 - Lake Chelan National Recreation Area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Lake Chelan National... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.62 Lake Chelan National... snowmobiles the following locations within the Lake Chelan National Recreation Area: (1) All open...

  13. Plan for hydrologic study of an area to be surface mined for coal in northwestern Colorado

    USGS Publications Warehouse

    Williams, Robert S.; Driver, Nancy E.

    1982-01-01

    A data-collection network was established in 1980 in northwestern Colorado in a drainage basin which may be surface mined for coal. This report describes the work plan set up to study the premining hydrology of this area near Steamboat Springs, Routt County, Colorado. The bedrock, alluvial, and surface-water systems as well as the climatic inputs to these systems, are monitored for this study.

  14. Effect of power plant emission reductions on a nearby wilderness area: a case study in northwestern Colorado.

    PubMed

    Mast, M Alisa; Ely, Daniel

    2013-09-01

    This study evaluates the effect of emission reductions at two coal-fired power plants in northwestern Colorado on a nearby wilderness area. Control equipment was installed at both plants during 1999-2004 to reduce SO2 and NOx emissions. One challenge was separating the effects of local from regional emissions, which also declined during the study period. The long-term datasets examined confirm that emission reductions had a beneficial effect on air and water quality in the wilderness. Despite a 75 % reduction in SO2 emissions, sulfate aerosols measured in the wilderness decreased by only 20 %. Because the site is relatively close to the power plants (<75 km), the slow rate of conversion of SO2 to sulfate, particularly under conditions of low relative humidity, might account for this less than one-to-one response. On the clearest days, emissions controls appeared to improve visibility by about 1 deciview, which is a small but perceptible improvement. On the haziest days, however, there was little improvement perhaps reflecting the dominance of regional haze and other components of visibility degradation particularly organic carbon and dust. Sulfate and acidity in atmospheric deposition decreased by 50 % near the southern end of the wilderness of which 60 % was attributed to power plant controls and the remainder to reductions in regional sources. Lake water sulfate responded rapidly to trends in deposition declining at 28 lakes monitored in and near the wilderness. Although no change in the acid-base status was observed, few of the lakes appear to be at risk from chronic or episodic acidification. PMID:23355020

  15. Effects of simulated solar UVB radiation on early developmental stages of the northwestern salamander (Ambystoma gracile) from three lakes

    USGS Publications Warehouse

    Calfee, R.D.; Little, E.E.; Pearl, C.A.; Hoffman, R.L.

    2010-01-01

    Solar ultraviolet radiation (UV) has received much attention as a factor that could play a role in amphibian population declines. UV can be hazardous to some amphibians, but the resultant effects depend on a variety of environmental and behavioral factors. In this study, the potential effects of UV on the Northwestern Salamander, Ambystoma gracile, from three lakes were assessed in the laboratory using a solar simulator. We measured the survival of embryos and the survival and growth of larvae exposed to four UV treatments in controlled laboratory studies, the UV absorbance of egg jelly, oviposition depths in the lakes, and UV absorbance in water samples from the three lakes. Hatching success of embryos decreased in the higher UV treatments as compared to the control treatments, and growth of surviving larvae was significantly reduced in the higher UVB irradiance treatments. The egg jelly exhibited a small peak of absorbance within the UVB range (290-320 nm). The magnitude of UV absorbance differed among egg jellies from the three lakes. Oviposition depths at the three sites averaged 1.10 m below the water surface. Approximately 66 of surface UVB radiation was attenuated at 10-cm depth in all three lakes. Results of this study indicate that larvae may be sensitive to UVB exposure under laboratory conditions; however, in field conditions the depths of egg deposition in the lakes, absorbance of UV radiation by the water column, and the potential for behavioral adjustments may mitigate severe effects of UV radiation. Copyright 2010 Society for the Study of Amphibians and Reptiles.

  16. Geohydrology of the lowland lakes area, Anchorage, Alaska

    USGS Publications Warehouse

    Zenone, Chester

    1976-01-01

    Unconsolidated deposits, chiefly of glacial origin, make up the surficial geologic materials in the Anchorage lowland lakes area , the western part of the Anchorage glacial outwash plain. Postglacial accumulation of peat, commonly 5 to 10 feet thick, and the presence of ground water at or very near the surface combine to create the swamp-muskeg terrane of much of the area. Deeper, confined ground water is also present beneath thick silt and clay layers that underlie the surficial deposits. Domestic water supply for the lowland lakes area is provided largely by public-supply wells completed in the deep, confined aquifers. No large perennial streams traverse the area, thus streamflow is not a major parameter in the area 's natural water balance. The major uses of surface water are recreational, including fishing and boating at several of the larger lakes, and private and commercial aircraft operations at Hood-Spenard Lakes floatplane base. The hydrology and water balance of these lakes is complex. Water levels in some lakes appear to be closely related to adjacent ground-water levels. Other lakes are evidently perched above the local water table. The relation of lake level to adjacent ground-water level may vary along the shoreline of a single lake. The effect of residential development practices on lake basin water balance is not completely understood. At Sand Lake, the largest lake in this area of rapid urbanization, the water level has declined about 6 feet since the early 1960's. (Woodard-USGS)

  17. The Ostracoda assemblage of the Eocene-Oligocene transition in northwestern Thrace: Kırklareli-Edirne area (northwestern Turkey)

    NASA Astrophysics Data System (ADS)

    Şafak, Ümit; Güldürek, Manolya

    2016-05-01

    The aim of the study is to investigate the Eocene-Oligocene transition in detail in northwest Thrace (NW Turkey) with heavy reliance on ostracod fauna. The lithologies formed and the environmental changes during this time period were also studied. The study was carried out in northwest Thrace within the outcropping Koyunbaba, Soğucak, and Ceylan Formations; Mezardere, Osmancık, and Danişmen Formations of the Yenimuhacir Group; and the Taşlısekban and Pınarhisar members of the Danişmen Formation. Rich ostracod fauna indicating an Eocene and Oligocene age and environment are found within these units. The Ostracoda fauna identified were ostracods Triebelina punctata, Bairdia cymbula, Bairdia tenuis, Cyamocytheridea nova, Krithe bartonensis, Krithe angusta, Krithe rutoti, Krithe parvula, Echinocythereis isabenana, Leguminocythereis genappensis, Grinioneis triebeli, Xestoleberis subglobosa and Xestoleberis muelleriana from the Mid-Late Eocene epoch; Cytheromorpha zinndorfi, Hemicyprideis montosa, Neocyprideis williamsoniana, Cladarocythere apostolescui, Hammatocythere hebertiana, Haplocytheridea helvetica, Cytheridea pernota, Callistocythereis vitilis, Cushmanidea cf. scrobiculata, Pterygocythereis fimbriata, Pokornyella limbata, Grinioneis paijenborchiana, Cytheretta tracensis, Macrocypris wrightii and Paracypris bouldnorensis from the Late Eocene-Early Oligocene epoch; and Novocypris eocenana, Novocypris striata, Moenocypris forbesi, Candona (Pseudocandona) fertilis, Candona (Lineocypris) sp. and Cypridopsis soyeri from the Early-Late Oligocene epoch. The study was also correlated to previous research conducted on Eocene-Oligocene age ostracods around the area, in northwestern Europe, and in the Paris-Akiten Basin, in view of similar age-environment relationships determined by said studies. On the basis of evidence from the lithologic content of the beds and the micropaleontological investigation, the fossil community identified in this study indicates that the

  18. Investigation of thiamine and PCB association with early life stage fry mortality in lake trout from northwestern Lake Michigan in 1996-1998

    USGS Publications Warehouse

    Honeyfield, Dale C.; Beltman, Dong; Holey, Mark; Edsall, Carol C.

    2005-01-01

    Lake trout (Salvelinus namaycush) eggs were collected from 72 females near Sturgeon Bay, WI in northwestern Lake Michigan from 1996, 1997, and 1998 to determine the relationships between egg thiamine and polychlorinated biphenyl (PCB) concentrations with egg fertilization and hatch, prevalence of abnormal fry, and fry mortality. Fry mortality consistent with early mortality syndrome (EMS) was observed in eggs from 33% of the females in 1996, 25% in 1997, and 28% in 1998. Among egg lots exhibiting EMS, fry mortality averaged 95% in 1996, 63% in 1997 and 77% in 1998 compared to 2% or less in lots that did not exhibit EMS. Expression of EMS was strongly correlated with egg thiamine concentrations; egg lots with less than approximately 1 nmol/g total thiamine consistently exhibited high rates of EMS, whereas egg batches with greater than 1.5 nmol/g showed little or no incidence of EMS among swim-up fry. Egg thiamine concentration was not related to fertilization rate, egg hatch, or the prevalence of abnormal fry. There was no relationship between egg concentrations of PCBs or tetrachlorinated dibenzo-p-dioxin (TCDD) equivalents (from PCBs, dioxins, and furans) and any of the egg or fry viability measurements, including EMS. We concluded that fry mortality observed in Lake Michigan lake trout in 1996-1998 was not caused by the toxicity of PCBs, dioxins, and furans, but is due to low egg thiamine concentrations.

  19. Neoglaciation, glacier-dammed lakes, and vegetation change in northwestern British Columbia, Canada

    SciTech Connect

    Clague, J.J. |; Mathewes, R.W.

    1996-02-01

    An integrated geomorphic, stratigraphic, paleoecological, and geochronological study of a system of linked valley glaciers and ice-dammed lakes has provided insights into the Neoglacial history and climate of the northern Coast Mountains of British Columbia. Cores collected from a small lake in the glacier foreland of Berendon Glacier and pits dug in a nearby fen record Little Ice Age and earlier Neoglacial advances. AMS and conventional radiocarbon dating of fossil plant material from these sites, supplemented by dendrochronological data, indicate that the Little Ice Age began more than 500 yr ago and peaked in the early 17th century. A middle Neoglacial advance of comparable extent occurred about 2200 to 2800 yr ago. The chronology of Neoglacial advances is generally similar to that at other sites in western Canada, although the Little Ice Age may have peaked as much as 100 yr earlier in our study area than elsewhere. The Little Ice Age advances are also broadly synchronous with those in other parts of the world, suggesting that they were caused by global changes in climate.

  20. Aquatic balance in Vegoritis Lake, West Macedonia, Greece, relating to lignite mining works in the area

    NASA Astrophysics Data System (ADS)

    Dimitrakopoulos, D.; Grigorakou, E.; Koumantakis, J.

    2003-04-01

    Vegoritis Lake, which is located at Vegoritis closed Basin in West Macedonia, Greece, is the biggest lake in Greece. In 1994 the area of the lake was 35 Km2 with maximum depth 42 m at the northwestern part of the lake. It is the final receiving body of the surface runoff of the hydrological basin. Moreover, it is the surficial appearance of an enormous and not well-known karstic aquifer. Being a closed hydrological basin any interference in surface or groundwater conditions in every part of its area affects the level of the lake. The level of the lake in 1900 was 525 masl, in 1942 was 542 masl reaching the higher level of 543 masl in 1956. The increase of the level of the lake was due to the drainage of Ptolemais (Sarigiol) swamp through Soulou drain ditches that transfer the water in the lake. Since then, a continuous drawdown took place with small periods of rising of water level. Today, the level of the lake is declined in a smaller rate having reached the level of 510 masl. Water coming from the lake has been used in the past, and in some cases still does, for agricultural, industrial and domestic use, for hydropower generation and for the cooling system of power plants. Moreover, P.P.C. (Public Power Corporation of Greece) develops an intense activity in the area with the exploitation of the lignite deposits of the basin and power generation in several Power Plants. Few years ago significant quantities from Vegoritis Lake were used for hydro power of Agras Power Plant. With the elaboration of the existent data (water level measurements, recharge, discharge) the connection between the lowering of the surface of the lake and the subtracted quantities through the Arnissa Tunel the first years of its use, is obvious. The last twenty years the condition has change. Outflow through the Arnissa Tunnel for hydropower has stopped. The continued lowering of the level of the lake is caused, mainly, by overexploitation due to the intense increase of the irrigating land

  1. Simulated Effects of Ground-Water Augmentation on the Hydrology of Round and Halfmoon Lakes in Northwestern Hillsborough County, Florida

    USGS Publications Warehouse

    Yager, Richard M.; Metz, P.A.

    2004-01-01

    Pumpage from the Upper Floridan aquifer in northwest Hillsborough County near Tampa, Florida, has induced downward leakage from the overlying surficial aquifer and lowered the water table in many areas. Leakage is highest where the confining layer separating the aquifers is breached, which is common beneath many of the lakes in the study area. Leakage of water to the Upper Floridan aquifer has lowered the water level in many lakes and drained many wetlands. Ground water from the Upper Floridan aquifer has been added (augmented) to some lakes in an effort to maintain lake levels, but the resulting lake-water chemistry and lake leakage patterns are substantially different from those of natural lakes. Changes in lake-water chemistry can cause changes in lake flora, fauna, and lake sediment composition, and large volumes of lake leakage are suspected to enhance the formation of sinkholes near the shoreline of augmented lakes. The leakage rate of lake water through the surficial aquifer to the Upper Floridan aquifer was estimated in this study using ground-water-flow models developed for an augmented lake (Round Lake) and non-augmented lake (Halfmoon Lake). Flow models developed with MODFLOW were calibrated through nonlinear regression with UCODE to measured water levels and monthly net ground-water-flow rates from the lakes estimated from lake-water budgets. Monthly estimates of ground-water recharge were computed using an unsaturated flow model (LEACHM) that simulated daily changes in storage of water in the soil profile, thus estimating recharge as drainage to the water table. Aquifer properties in the Round Lake model were estimated through transient-state simulations using two sets of monthly recharge rates computed during July 1996 to February 1999, which spanned both average conditions (July 1996 through October 1997), and an El Ni?o event (November 1997 through September 1998) when the recharge rate doubled. Aquifer properties in the Halfmoon Lake model were

  2. 36 CFR 7.55 - Lake Roosevelt National Recreation Area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Lake Roosevelt National... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.55 Lake Roosevelt National...) Aircraft. Float planes may be operated on Lake Roosevelt on those waters not administered by Indians...

  3. 36 CFR 7.55 - Lake Roosevelt National Recreation Area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Lake Roosevelt National... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.55 Lake Roosevelt National...) Aircraft. Float planes may be operated on Lake Roosevelt on those waters not administered by Indians...

  4. WILD CATTLE MOUNTAIN AND HEART LAKE ROADLESS AREAS, CALIFORNIA.

    USGS Publications Warehouse

    Muffler, L.J. Patrick; Denton, David K., Jr.

    1984-01-01

    The results of geologic, geochemical, and geophysical surveys in Wild Cattle Mountain and Heart Lake Roadless Areas in California indicate little promise for the occurrence of metallic, nonmetallic, or fossil fuel resources. However, Wild Cattle Mountain Roadless Area and part of Heart Lake Roadless Area lie in Lassen Known Geothermal Resources Area, and noncompetitive geothermal lease applications have been filed on much of the rest of Heart Lake Roadless Area. Both areas are adjacent to Lassen Volcanic National Park. Geochemical and geologic data indicate that the thermal manifestations in the Park and at Growler and Morgan Hot Springs just southwest of Wild Cattle Mountain Roadless Area are part of the same large geothermal system. Consequently, the entire Wild Cattle Mountain Roadless Area and part of the Heart Lake Roadless Area have a substantiated geothermal resource potential; the rest of the Heart Lake Roadless Area has a probable geothermal resource potential.

  5. Distribution of metals (Fe, Mn, Zn, Cu) in fish tissues in two lakes of different trophy in Northwestern Poland.

    PubMed

    Rajkowska, Monika; Protasowicki, Mikołaj

    2013-04-01

    This study presents concentrations of iron, manganese, zinc, and copper in selected tissues of two fish species: pike (Esox lucius L.) and bream (Abramis brama L.) living in lakes Ińsko and Wisola, Northwestern Poland. The lakes differ in their trophic status. The effect of gender and environmental conditions on metals accumulation was also investigated. Metal analyses were performed using inductively coupled plasma atomic emission spectroscopy. Considering all studied fish species and tissues, the average metal concentrations (micrograms per gram wet weight) in both lakes occurred in the following ranges: Fe 0.8-240.6, Mn 0.2-8.4, Zn 3.0-185.9, and Cu 0.14-7.76. The lowest levels of the studied metals were always detected in the muscles. The spleen, kidneys, and liver were found to accumulate the highest amounts of Fe. In the case of the other metals, the highest levels were found, as follows: Mn in skin, gills, and gonads, Zn in digestive tract and gills, Cu in liver. Heavy metal content in fish gonads was observed to be sex dependent. PMID:22923375

  6. A Holocene record of endogenic iron and manganese precipitation, isotopic composition of endogenic carbonate, and vegetation history in a lake-fen complex in northwestern Minnesota

    USGS Publications Warehouse

    Dean, Walter E.; Doner, Lisa A.

    2011-01-01

    Little Shingobee Lake and Fen are part of an extensive network of lakes and wetlands in the Shingobee River headwaters area of northwestern Minnesota. Prior to about 9800 radiocarbon years, most of the lakes in the Shingobee watershed area were interconnected to form glacial Lake Willobee. From 9800 to 7700 radiocarbon years, the level of Lake Willobee fell as a result of breaching of a dam, leaving small separated basins containing the existing lakes and wetlands. The dominant components in the sediments in a 9-meter core from Little Shingobee Lake (LSL-B), and lacustrine sediments under 3.3 meters of peat in a 17-meter core from Little Shingobee Fen (LSF-10) are detrital clastic material, endogenic CaCO3, and organic matter. The detrital fraction in the Holocene section in core LSL-B varies considerably from 7 weight percent to 82 weight percent and closely parallels the concentration of detrital quartz measured by X-ray diffraction. The CaCO3 concentration, which also varies considerably from 10 weight percent to 70 weight percent, is generally antithetic to the detrital concentration owing to the dilution of detrital material by CaCO3, particularly during the early to middle Holocene (about 9000-6500 calendar years). The organic-matter content varies from 5 weight percent to 25 weight percent and, together with CaCO3, serves to dilute the allogenic detrital fraction. In both cores almost all of the iron (Fe) and manganese (Mn) is in endogenic minerals, presumed to be oxyhydroxide minerals, that are important components throughout the core; little Fe and Mn are contributed by detrital aluminosilicate minerals. The endogenic Fe mineral, calculated as Fe(OH)3, forms a larger percentage of the sediment than endogenic organic material throughout most of the Holocene section in the LSL-B core and in the lacustrine sediments below the peat in the LSF-10 core. Biogenic silica as opal (biopal; diatom debris) was not measured, but the average calculated biopal is 5

  7. Influence of Salinity on the Bacterial Community Composition in Lake Bosten, a Large Oligosaline Lake in Arid Northwestern China

    PubMed Central

    Tang, Xiangming; Xie, Guijuan; Shao, Keqiang; Sai·Bayartu; Chen, Yuangao

    2012-01-01

    Salinity was found to be the dominating contributor controlling bacterial community composition (BCC) and the abundance of Betaproteobacteria in the oligosaline Lake Bosten. The high percentage of unclassified bacteria inhabiting this unique habitat highlights the potential ecological importance of BCC in the early stage of lake salinization and eutrophication. PMID:22522679

  8. Identifying the origin and geochemical evolution of groundwater using hydrochemistry and stable isotopes in Subei Lake Basin, Ordos energy base, Northwestern China

    NASA Astrophysics Data System (ADS)

    Liu, F.; Song, X.; Yang, L.; Zhang, Y.; Han, D.; Ma, Y.; Bu, H.

    2014-05-01

    A hydrochemical and isotopic study was conducted in Subei Lake Basin, northwestern China, to identify the origin and geochemical evolution of groundwater. Water samples were collected, major ions and stable isotopes (δ18O, δ D) were analyzed. In terms of hydrogeological conditions in study area, groundwater can be classified into three types: the Quaternary groundwater, the shallow Cretaceous groundwater, the deep Cretaceous groundwater. Piper diagram and correlation analysis were used to reveal the hydrochemical characteristics of water resources. The dominant water type of lake water was Na-Cl type, which was controlled by strong evaporation and recharge from overland flow and groundwater; the predominant hydrochemical types for groundwater were Ca-HCO3, Na-HCO3, and mixed Ca · Na · Mg-HCO3 types, the groundwater chemistry is mainly controlled by dissolution/precipitation of anhydrite, gypsum, halite and calcite. The dedolomitization and cation exchange are also important factors. Rock weathering is confirmed to play a leading role in the mechanisms responsible for the chemical compositions of groundwater. The stable isotopic values of oxygen and hydrogen in groundwater are close to the local meteoric water line, showing that groundwater is of meteoric origin. The deep Cretaceous groundwater is depleted in heavy isotopes, compared to shallow Cretaceous groundwater. The hydrogen and oxygen isotopes signatures in deep Cretaceous groundwater may show a paleorecharge effect that the deep Cretaceous groundwater was recharged during a geologic period when the climate was wetter and colder than today. Due to strong evaporation effect and dry climatic conditions, heavy isotopes are more enriched in lake water than groundwater. The hydrochemical and isotopic information of utmost importance has been provided to decision-makers by the present study so that a sustainable water resources management policy could be designed for the Ordos energy base.

  9. Application of the Local Grid Refinement package to an inset model simulating the interactions of lakes, wells, and shallow groundwater, northwestern Waukesha County, Wisconsin

    USGS Publications Warehouse

    Feinstein, D.T.; Dunning, C.P.; Juckem, P.F.; Hunt, R.J.

    2010-01-01

    Groundwater use from shallow, high-capacity wells is expected to increase across southeastern Wisconsin in the next decade (2010-2020), owing to residential and business growth and the need for shallow water to be blended with deeper water of lesser quality, containing, for example, excessive levels of radium. However, this increased pumping has the potential to affect surface-water features. A previously developed regional groundwater-flow model for southeastern Wisconsin was used as the starting point for a new model to characterize the hydrology of part of northwestern Waukesha County, with a particular focus on the relation between the shallow aquifer and several area lakes. An inset MODFLOW model was embedded in an updated version of the original regional model. Modifications made within the inset model domain include finer grid resolution; representation of Beaver, Pine, and North Lakes by use of the LAK3 package in MODFLOW; and representation of selected stream reaches with the SFR package. Additionally, the inset model is actively linked to the regional model by use of the recently released Local Grid Refinement package for MODFLOW-2005, which allows changes at the regional scale to propagate to the local scale and vice versa. The calibrated inset model was used to simulate the hydrologic system in the Chenequa area under various weather and pumping conditions. The simulated model results for base conditions show that groundwater is the largest inflow component for Beaver Lake (equal to 59 percent of total inflow). For Pine and North Lakes, it is still an important component (equal, respectively, to 16 and 5 percent of total inflow), but for both lakes it is less than the contribution from precipitation and surface water. Severe drought conditions (simulated in a rough way by reducing both precipitation and recharge rates for 5 years to two-thirds of base values) cause correspondingly severe reductions in lake stage and flows. The addition of a test well

  10. Characterization of ambient fine particles in the northwestern area and Anchorage, Alaska.

    PubMed

    Kim, Eugene; Hopke, Philip K

    2008-10-01

    Ambient PM2.5 (particulate matter less than 2.5 microm in aerodynamic diameter) in the northwestern United States and Alaska is dominated by carbonaceous compounds associated with wood burning and transportation sources. PM2.5 source characterization studies analyzing recent PM2.5 speciation data have not been previously reported for these areas. In this study, ambient PM2.5 speciation samples collected at two monitoring sites located in the northwestern area, Olympic Peninsula, WA, and Portland, OR, and one monitoring site located in Anchorage, AK, were characterized through source apportionments. Gasoline vehicle, secondary sulfate, and wood smoke were the largest sources of PM2.5 collected at the Anchorage, Olympic, and Portland monitoring sites, respectively. Secondary sulfates showed an April peak at Anchorage and a November peak at Portland that are likely related to the increased photochemical reaction and long-range transport in Anchorage and meteorological stagnation in Portland. Secondary nitrate at the Olympic site showed a weak summer high peak that could be caused by seasonal tourism in the national park. Backward trajectories suggested that the elevated aged sea salt concentrations at the Portland monitoring site could be regional transport of sea salt that passed through other contaminated air sheds along the coast. Oil combustion emissions that might originate from ships and ferries were observed at the Olympic monitoring site. PMID:18939780

  11. Hydrology of the Lake Deaton and Lake Okahumpka area, Northeast Sumter County, Florida

    USGS Publications Warehouse

    Simonds, Edward P.; German, E.R.

    1980-01-01

    The Floridan aquifer in the Lake Deaton and Lake Okahumpka area is 50 to 130 feet below land surface. During the 16-year period 1963-78 lake evaporation exceeded rainfall by 0.4 inches. Drainage from Lake Deaton and its surrounding area goes into Chitty Chatty Creek and on the Hogeye Sink when the altitude of the potentiometric surface of the Floridan aquifer is low. During a higher altitude of the Floridan potentiometric surface, Hogeye Sink may discharge water; this water, along with the normal runoff, goes into Lake Okahumpka. Average lake fluctuation is 1.5 to 2.0 feet per year. Lake Deaton supports a large population of blue-green algae and Lake Okahumpka is choked with aquatic plants. The water quality of the two lakes differ, with Lake Deaton having a sodium chloride water and Lake Okahumpka having a calcium bicarbonate water. Analysis of water and bottom material samples showed that only cadmium and mercury exceeded the Florida Department of Environmental Regulation 's criteria for Class III waters; however, the amounts detected were at or slightly above the limits of the analytical method. (USGS)

  12. 36 CFR 7.69 - Ross Lake National Recreation Area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.69 Ross Lake National Recreation Area... the U.S./Canadian border to the end of the road at East Landing. (3) Access and circulatory roads...

  13. 36 CFR 7.69 - Ross Lake National Recreation Area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.69 Ross Lake National Recreation Area... the U.S./Canadian border to the end of the road at East Landing. (3) Access and circulatory roads...

  14. 36 CFR 7.69 - Ross Lake National Recreation Area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.69 Ross Lake National Recreation Area... the U.S./Canadian border to the end of the road at East Landing. (3) Access and circulatory roads...

  15. 36 CFR 7.69 - Ross Lake National Recreation Area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.69 Ross Lake National Recreation Area... the U.S./Canadian border to the end of the road at East Landing. (3) Access and circulatory roads...

  16. 36 CFR 7.69 - Ross Lake National Recreation Area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.69 Ross Lake National Recreation Area... the U.S./Canadian border to the end of the road at East Landing. (3) Access and circulatory roads...

  17. HOMESTEAD, LAKE FORK, AND LICK CREEK ROADLESS AREAS, OREGON.

    USGS Publications Warehouse

    Evans, James G.; Conyac, Martin D.

    1984-01-01

    A mineral survey concluded that the Homestead, Lake Fork and Lick Creek Roadless Area, Oregon offer little promise for the occurrence of mineral or energy resources in the bedrock. Probable mineral-resource potential is assigned to the west and north parts of the Lake Fork Roadless Area, where gold resources may occur in glacial deposits and alluvium transported into this area from sources outside the roadless area to the west.

  18. Indexes of hydrologic data from selected coal-mining areas in northwestern Colorado

    USGS Publications Warehouse

    Gaggiani, N.G.

    1989-01-01

    Currently (1988), data from hydrologic studies related to coal mining that have been done in northwestern Colorado since the early 1970 's are stored in the files of private companies and government offices and in various computer systems. To compile these data for additional research, a trip to each office would have to be made to determine the availability and acceptability of the data. The U.S. Geological Survey, in cooperation with the U.S. Bureau of Land Management and the Colorado Mined Land Reclamation Division, has created a database (COALDATA) that includes stream discharge, groundwater levels, and chemical analysis of water samples that were collected by private companies and government agencies other than the U.S. Geological Survey in and near selected coal mines in northwestern Colorado. Indexes in this report list 93 surface water sites and 95 groundwater sites where hydrologic data are available in the COALDATA data base. The indexes also list 62 surface water sites and 480 groundwater sites in the U.S. Geological Survey data base, which is separate from the COALDATA data base and contains only data collected by the U.S. Geological Survey. The combined output of the COALDATA data base and the U.S. Geological Survey data base provides surface water and groundwater data that include most of the study area. (USGS)

  19. Epidemiology of human brucellosis in a defined area of Northwestern Greece.

    PubMed

    Avdikou, I; Maipa, V; Alamanos, Y

    2005-10-01

    Despite a European co-financial programme for control and eradication of brucellosis in Southern Europe, there is evidence that foci of brucellosis still exists in Greece and other Southern European countries. Human brucellosis cases are probably underreported in these countries. A local surveillance system was implemented in a defined region of Northwestern Greece, in order to record and study all human brucellosis cases, using several sources of retrieval. A total of 152 newly diagnosed cases were recorded during a 2-year study period (from 1 April 2002 to 31 March 2004). The age- and sex-adjusted mean annual incidence rate for the population of the study area was 17.3 cases/10(5) inhabitants. Incomplete application of the control and eradication programme in livestock, and the possible illegal trafficking of animals and their products across the Greek-Albanian border could be responsible for the persistence of foci of brucellosis in the area. PMID:16181512

  20. Epidemiology of human brucellosis in a defined area of Northwestern Greece.

    PubMed Central

    Avdikou, I.; Maipa, V.; Alamanos, Y.

    2005-01-01

    Despite a European co-financial programme for control and eradication of brucellosis in Southern Europe, there is evidence that foci of brucellosis still exists in Greece and other Southern European countries. Human brucellosis cases are probably underreported in these countries. A local surveillance system was implemented in a defined region of Northwestern Greece, in order to record and study all human brucellosis cases, using several sources of retrieval. A total of 152 newly diagnosed cases were recorded during a 2-year study period (from 1 April 2002 to 31 March 2004). The age- and sex-adjusted mean annual incidence rate for the population of the study area was 17.3 cases/10(5) inhabitants. Incomplete application of the control and eradication programme in livestock, and the possible illegal trafficking of animals and their products across the Greek-Albanian border could be responsible for the persistence of foci of brucellosis in the area. PMID:16181512

  1. 2010 update—Streamflow characteristics at selected sites in southwestern Georgia, southeastern Alabama, and northwestern Florida, near Lake Seminole

    USGS Publications Warehouse

    Stamey, Timothy C.

    2011-01-01

    Since the first edition of this report was published in 1996, continuous streamflow data have been recorded in the tri-state area of Alabama, Georgia, and Florida, near Lake Seminole. Several notable floods and severe droughts have occurred during this additional 16-year period that have sparked the need to include these additional recorded data into a comprehensive report for use by local, State, and Federal agencies. Flow durations, low-flow, and mean-flow analyses of daily mean discharges were compiled and analyzed for 12 streamflow stations during three selected periods that included pre-Lake Seminole (1929-53), post-Lake Seminole and pre-irrigation (1958-70), and post-Lake Seminole and post-irrigation (1976-2010), as well as for specified partial periods. The analyses yielded information on the variability of inflow to and outflow from Lake Seminole and the variability of flows in area streams. Streamflow characteristics for Ichawaynochaway Creek at Milford, Georgia, and Chipola River near Altha, Florida, varied similarly from 1944-53 to 1958-70, with mean annual flows decreasing by about 8 and 6 percent, respectively. This decreasing trend continued from 1958-70 to 1976-2010 by about 10 and 2 percent, respectively. The mean annual streamflow for Spring Creek near Iron City, Georgia, however, remained basically unchanged from 1944-53 to 1958-70, as well as from 1958-70 to 1976-2010. Streamflow characteristics for inflow to and outflow from Lake Seminole varied similarly during 1929-53, 1958-70, and 1976-2010. Mean 30-day low flows for inflow and outflow at Lake Seminole increased by about 24 to 11 percent, respectively, from 1929-53 to 1958-70; the values for 1976-2010 returned to near, but less than, the low-flow values of 1929-53.

  2. 36 CFR 7.57 - Lake Meredith National Recreation Area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... launched at designated launch sites established by the Superintendent in accordance with 36 CFR 1.5 and 1.7... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Lake Meredith National... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.57 Lake Meredith...

  3. 36 CFR 7.57 - Lake Meredith National Recreation Area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... launched at designated launch sites established by the Superintendent in accordance with 36 CFR 1.5 and 1.7... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Lake Meredith National... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.57 Lake Meredith...

  4. A Holocene record of endogenic iron and manganese precipitation and vegetation history in a lake-fen complex in northwestern Minnesota

    USGS Publications Warehouse

    Dean, W.E.; Doner, L.A.

    2012-01-01

    Little Shingobee Lake and Fen are part of the extensive network of lakes and wetlands in the Shingobee River headwaters of northwestern Minnesota, designed to study the interactions between surface and ground waters. Prior to about 11. 2 cal. ka, most of these lakes and wetlands were interconnected to form glacial Lake Willobee, which apparently formed when a debris flow dammed the Shingobee River. Between 11. 2 and 8. 5 cal. ka, the level of Lake Willobee fell as a result of breaching of the dam, transforming the deep lake into the existing lakes and wetlands. Analyses of a 9-m core from Little Shingobee Lake (LSL-B), and lacustrine sediments under 3. 3 m of peat in a 17-m core from Little Shingobee Fen (LSF-10), show that the dominant components are allogenic clastic material, and endogenic CaCO3 and organic matter. In both cores almost all of the iron (Fe) and manganese (Mn) are incorporated in endogenic minerals, presumed to be X-ray amorphous oxyhydroxide minerals, that occur in significant quantities throughout the cores; almost no Fe and Mn are contributed from detrital aluminosilicate minerals. This suggests that, for most of the Holocene, the allogenic watershed contributions to lake chemistry were minor compared to the dissolved mineral load. In addition, prior to 3. 5 cal. ka, pollen zone boundaries coincide with large changes in lake-sediment mineralogy, indicating that both landscape and climate processes were linked to early- and mid-Holocene lake chemistry. The pollen time series, with sequential domination by spruce, pine, sagebrush-oak, birch-oak and, finally, white pine is typical of the region and reflects the changing location of the prairie-forest transition zone over time. These changes in vegetation had some profound effects on the geochemistry of the lake waters. ?? 2011 Springer Science+Business Media B.V. (outside the USA).

  5. 33 CFR 334.820 - Lake Michigan; naval restricted area, U.S. Naval Training Center, Great Lakes, Ill.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Lake Michigan; naval restricted area, U.S. Naval Training Center, Great Lakes, Ill. 334.820 Section 334.820 Navigation and Navigable... REGULATIONS § 334.820 Lake Michigan; naval restricted area, U.S. Naval Training Center, Great Lakes, Ill....

  6. 33 CFR 334.820 - Lake Michigan; naval restricted area, U.S. Naval Training Center, Great Lakes, Ill.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Lake Michigan; naval restricted area, U.S. Naval Training Center, Great Lakes, Ill. 334.820 Section 334.820 Navigation and Navigable... REGULATIONS § 334.820 Lake Michigan; naval restricted area, U.S. Naval Training Center, Great Lakes, Ill....

  7. Lake and bog development at Glimmerglass lake in the Sylvania Wilderness Area, Michigan

    SciTech Connect

    Brugam, R.B.; Owen, B.; McKeever, K.

    1995-06-01

    We used pollen and diatom analysis to reconstruct post-glacial development of Glimmerglass Lake and its adjacent Sphagnum peatland using transacts of cores. Glimmerglass lake has existed since late-glacial times with little or no change in water levels. In contrast the peatland began growing as a floating mat in a pond that was separated from the main lake by a spit of land. Over time, the floating mat became grounded in the pond but continued growing to cover an adjacent low area that had never been underwater. The peatland continues to grow even though it is approximately 2 m above the level of the adjacent lake. It seems that the peat has slowed drainage into the lake and allowed the peatland to grow above the level of the lake. It is unclear whether climatic change or hydrology controls the rate of accumulation of the peat.

  8. Annual burned area across a precipitation gradient in northwestern patagonia steppe

    NASA Astrophysics Data System (ADS)

    Oddi, Facundo; Ghermandi, Luciana; Lasaponara, Rosa

    2013-04-01

    study area in relation to precipitation gradient establishing two zones (wet and xeric). To delimit area of wildfires on Landsat scenes we used the NBR index. Then, we calculated the annual burned area in each zone, compared the annual burned area between zones and also explored relationships between that variable of the fire regime and precipitation/temperature data. We expect to contribute to the discussions about the importance of drought/fuel on the fire activity across the productivity/aridity gradient, specifically on Mediterranean environments. Finally, with this work we expect to improve future management and conservation practices in Northwestern Patagonia grasslands.

  9. Northwestern salamanders Ambystoma gracile in mountain lakes: record oviposition depths among salamanders

    USGS Publications Warehouse

    Hoffman, R., Jr.; Pearl, C.A.; Larson, G.L.; Samora, B.

    2012-01-01

    Oviposition timing, behaviors, and microhabitats of ambystomatid salamanders vary considerably (Egan and Paton 2004; Figiel and Semlitsch 1995; Howard and Wallace 1985; Mac-Cracken 2007). Regardless of species, however, females typically oviposit using sites conducive to embryo development and survival. For example, the results of an experiment by Figiel and Semlitsch (1995) on Ambystoma opacum (Marbled Salamander) oviposition indicated that females actively selected sites that were under grass clumps in wet versus dry treatments, and surmised that environmental conditions such as humidity, moisture, and temperature contributed to their results. Other factors associated with ambystomatid oviposition and embryo survival include water temperature (Anderson 1972; Brown 1976), dissolved oxygen concentration (Petranka et al. 1982; Sacerdote and King 2009), oviposition depth (Dougherty et al. 2005; Egan and Paton 2004), and oviposition attachment structures such as woody vegetation (McCracken 2007; Nussbaum et al. 1983). Resetarits (1996), in creating a model of oviposition site selection for anuran amphibians, hypothesized that oviparous organisms were also capable of modifying oviposition behavior and site selection to accommodate varying habitat conditions and to minimize potential negative effects of environmental stressors. Kats and Sih (1992), investigating the oviposition of Ambystoma barbouri (Streamside Salamander) in pools of a Kentucky stream, found that females preferred pools without predatory Lepomis cyanellus (Green Sunfish), and that the number of egg masses present in a pool historically containing fish increased significantly the year after fish had been extirpated from the pool. Palen et al. (2005) determined that Ambystoma gracile (Northwestern Salamander) and Ambystoma macrodactylum (Longtoed Salamander) eggs were deposited either at increased depth or in full shaded habitats, respectively, as water transperancy to UV-B radiation increased.

  10. Growth and potential yield of perch (Perca spp.) in selected areas of Lake Baikal and the Laurentian Great Lakes

    USGS Publications Warehouse

    O'Gorman, Robert; Bronte, Charles R.; Hatcher, Charles O.; Pronin, Nikolai M.; Sokolnikov, Yury

    1998-01-01

    We compared growth, mortality, and potential yield of Eurasian perch (Perca fluviatilis) from Chivirkui Bay in Lake Baikal with that of yellow perch (P. flavescens) from three areas of the Laurentian Great Lakes --Chequamegon Bay in Lake Superior, northeastern Lake Ontario, and southwestern Lake Erie. Graded mesh gill nets were fished in August to sample perch in lakes Baikal (1993), Ontario (1985-93), and Erie (1994). Bottom trawls were fished in July-August to sample perch in Lake Superior (1973-93). Adult yellow perch from the Laurentian Great Lakes were heavier at most lengths than adult Eurasian perch from Lake Baikal. The increase in body weight per unit increase in length was greatest in Lake Erie. Total annual mortality of perch was low in Lake Baikal (0.31), intermediate in lakes Superior (0.41) and Ontario (0.54), and high in Lake Erie (0.66). Annual fishing mortality (u) for perch in Lake Baikal was 60%-70% lower than that for perch in the Great Lakes. At ages 1-3, perch in Lake Erie were longer than those in lakes Baikal, Superior, and Ontario but at ages 4-9 perch in Lake Baikal were longer than those in the other lakes. Although Eurasian perch in Lake Baikal were longer at age 4 and older, growth in length, as measured by the Brody growth coefficient, K, was lower there than in the other lakes and was similar to that in Lake Superior; yellow perch in Lake Erie grew the fastest. Yield-per-recruit was lowest in Lake Erie and highest in Lake Superior. Potential yield was influenced by growth rates and fishing mortality.

  11. Remotely Sensed Estimates of Evapotranspiration in Agricultural Areas of Northwestern Nevada: Drought, Reliance, and Water Transfers

    NASA Astrophysics Data System (ADS)

    Bromley, Matthew

    The arid landscape of northwestern Nevada is punctuated by agricultural communities that rely on water primarily supplied by the diversion of surface waters and secondarily by groundwater resources. Annual precipitation in the form of winter snowfall largely determines the amount of surface water that is available for irrigation for the following agricultural growing season. During years of insufficient surface water supplies, particular basins can use groundwater in order to meet irrigation needs. The amount of water used to irrigate agricultural land is influenced by land use changes, such as fallowing, and water right transfers from irrigation to municipal use. To evaluate agricultural water consumption with respect to variations in weather, water supply, and land use changes, monthly estimates of evapotranspiration (ET) were derived from Landsat multispectral optical and thermal imagery over a eleven-year period (2001 to 2011) and compared to variations in weather, water supply, and land use across four hydrographic areas in northwestern Nevada. Monthly ET was estimated using a land surface energy balance model, Mapping EvapoTranspiration at high Resolution with Internalized Calibration (METRIC), using Landsat 5 and Landsat 7 imagery combined with local atmospheric water demand estimates. Estimates of net ET were created by subtracting monthly precipitation from METRIC-derived ET, and seasonal estimates were generated by combining monthly ET for April-October (the regional agricultural growing season). Results highlight that a range of geographic, climatic, hydrographic, and anthropogenic factors influence ET. Hydrographic areas such as Mason Valley have the ability to mitigate deficiencies in surface water supplies by pumping supplemental groundwater, thereby resulting in low annual variability in ET. Conversely, the community of Lovelock has access to limited upstream surface water storage and is restricted by groundwater that is saline and unsuitable for

  12. CONTOURITES IN LAKE SUPERIOR

    EPA Science Inventory

    Contour currents influence sedimentation in an area 15 km wide and 65 km long at the base of the slope off the Keweenaw Peninsula in Lake Superior, northwestern Michigan. Seismic-reflection profiles (3.5 kHz) from this area show distinct wavy reflectors in a scoured trough at a d...

  13. Remote sensing monitoring study for water area change of Fuxian Lake in last 40 years

    NASA Astrophysics Data System (ADS)

    Li, Jia; Wang, Jinliang; Duan, Ping

    2015-12-01

    Fuxian Lake located in the middle of Yunnan Province is second deepest lake in china. The water level of Fuxian Lake descends and its water area reduces in recent years owing to the climate changing. Therefore, it is crucial for rational utilization of lake resources to study the change trend of Fuxian Lake's area. Landsat images from 1974 to 2014 were used to monitor Fuxian Lake's area change. Monitoring results show that there are four apparent features of Fuxian Lake's area: (1) Years in which Fuxian Lake's area are larger are concentrated in 2006 to 2009. (2) From 1974 to 1990, Fuxian Lake's area change has a trend of decrease. (3) From 1990 to 2005, Fuxian Lake's area change shows a rise trend on the whole. (4) From 2005 to 2014, there is an obvious decrease trend of Fuxian Lake's area change.

  14. A boundary of stress-field orientation in northwestern area of the Kanto plain

    NASA Astrophysics Data System (ADS)

    Yano, T. E.; Takeda, T.; Shiomi, K.

    2014-12-01

    There is a boundary where pressure and tension axes dramatically change by almost at the right angles around northwestern area of the Kanto plain (north of Tokyo), reported by Suzuki (1989). Since 2013, we have launched Japan Unified High-resolution Relocated Catalog for Earthquakes (JUICE) project. The relocation method using the Double-Difference method (Waldhauser and Ellsworth, 2000) provided the high-resolution earthquake catalog, which enabled to further evaluate active faults (e.g. seismogenic layer thickness, or slip tendency direction etc.) In this presentation, we revisit the previous mystery regarding to the stress-field orientation boundary in northwestern Kanto plain by looking at much more and high-resolution data available than before. The stress axis boundary runs at particularly close (about 5 km north and parallel direction) to the Fukaya fault, which caused the M6.9 Western Saitama earthquake in 1931 occurred at very shallow depth, involving severe damages and many casualties in Kanto region. The high-resolution catalog clearly showed the majority of pressure (P-axis) and tension stress axis (T-axis) lie about 150˚ and 60˚ in the north of the stress axis boundary, while both the axes change into about 45˚ and 150˚ in the south of this boundary, respectively. In fact, both P- and T- axis, by crossing the boundary, suddenly changes about 90˚. The focal mechanism around this area dominated by the strike and thrust and both mechanisms seem to be randomly co-existing. Yet, depth distribution pattern changes abruptly across the boundary. The depth distribution pattern of north part of the boundary seems more confined than the southern part. We discuss the sharp stress discontinuity by two main perspectives. The first focuses on the effect due to local structure, such as possibly the buried Median tectonic line and/or ancient failed rift formed while the Sea of Japan had opened. The second focuses on the tectonic force due to complicated subduction

  15. Portion of the Great Lakes area as seen from Skylab

    NASA Technical Reports Server (NTRS)

    1974-01-01

    An oblique view of a portion of the Great Lakes (43.0N, 70.0W) area as seen from the Skylab space station in Earth orbit. lake Erie is in the foreground; and Lake Ontario is in the background. The Niagara Falls area is in the center of the photograph. Portions of Pennsylvania, New York, and Ontario, Canada are visible, but under nearly complete snow cover. Major structural features, drainage patterns, road systems and the cities of Buffalo and Toronto are easily distinguished and actually enhanced by the snow. At the time this picture was taken, these two Great Lakes had no observable ice, although cloud formations partially mask the southern shores of the two bodies of water.

  16. Etiologic Agents of Otomycosis in the North-Western Area of Iran

    PubMed Central

    Kazemi, Abdolhassan; Majidinia, Maryam; Jaafari, Abbasali; Ayatollahi Mousavi, Seyyed Amin; Zarei Mahmoudabadi, Ali; Alikhah, Hossein

    2015-01-01

    Background: Otomycosis is a superficial fungal infection often involves the pinna and external auditory canal. It is a pathologic condition, with Candida and Aspergillus, the most common fungal species. It is common worldwide but more prevalent in tropical and subtropical countries Objectives: The aim of this study was to determine the etiologic agents and local epidemiologic pattern of otomycosis in northwest Iran. Patients and Methods: A series of 140 patients with clinically symptomatic otomycosis were studied in 21 cities, towns, and villages throughout northwest Iran between 2009 and 2011. Clinical samples were collected by swabs and then assessed by mycological investigation. Results: Otomycosis was diagnosed in 129 cases (92%, 76 male, 53 female) with the highest prevalence of cases occurring in males between 21 - 40 years of age. From an etiological point of view, 116 patients (90%, 21 - 40 years old) were infected by saprophytic mold and 9 patients (7%) were infected by yeast. Three cases (2%) involved dermatophytes, and in one case (1%) the subject was infected with Eurotium (the perfect stage of Aspergillus fumigatus). Aspergillus niger was the most common mold that was isolated, followed by A. flavus, A. fumigatus, Penicillium spp., Fusarium spp., and Rhizopus spp. A total of 2 yeasts belonging to genus Candida, C. albicans and C. tropicalis, were isolated. Conclusions: Our study showed a high prevalence of otomycosis in the northwestern area of Iran. As such, proper diagnosis and treatment by aseptic techniques for this disease is urgently needed. PMID:26495108

  17. 3-D Seismic Tomographic Modelling of the North-Western Spitsbergen Area

    NASA Astrophysics Data System (ADS)

    Czuba, W.

    2015-12-01

    Deep seismic sounding measurements were performed in the continent-ocean transition zone of the north-western Svalbard continental margin in 1976 - 1999 in an international co-operation. Seismic energy (airgun and TNT shots) was recorded by land (onshore) seismic stations, ocean bottom seismometers (OBS), and ocean bottom hydrophone systems (OBH). Data from archival and modern seismic profiles were altogether used for 3-D tomographic inversion using JIVE3D software. The modelling area was chosen to be a rectangle of 420 x 330 km (Fig.). The results are similar to the earlier 2-D modelling, supplemented by off-line information from the profiles and the SPITS permanent station, giving a 3-D image of the crustal structure and Moho interface shape. The continental crust thins to the west and north. A minimum depth of about 6 km to the Moho discontinuity was found east of the Molloy Deep and in the Knipovich Ridge. The Moho interface deepens to about 30 km beneath the continental crust of Spitsbergen.

  18. Biostratigraphy of a Middle Miocene-Pliocene sequence from Cumarebo area, Falcon State, northwestern Venezuela

    SciTech Connect

    Giffuni, G. )

    1991-03-01

    The southern Caribbean region offers little in the way of continuous sequences for the late Neogene. An upward facies shallowing trend unfavorable for planktonic foraminifers and erosional truncation seems to be almost a rule for such sediments. A fairly complete sedimentary sequence mainly represented by clays, silts, and carbonate rocks from the Cumarebo region, Falcon State, northwestern Venezuela, was chosen to study the biostratigraphy of the late Neogene using foraminifers. More than one hundred surface samples were analyzed throughout. The study of foraminiferal fossil assemblages and other microfossils was also used to define paleoenvironments of deposition. Four formations are involved in this work. From base to top they are the Socorro, Caujarao, El Veral, and Tucupido. From the study of planktonic foraminifers, six biostratigraphic zones were recognized: Globorotalia mayeri Zone, Globorotalia menardii Zone, Globorotalia acostaensis Zone, Globorotalia humerosa Zone, Globorotalia margaritae Zone, and Globorotalia miocenica Zone. These zones indicate that the age of the sequence ranks from late middle Miocene to middle Pliocene. Generally speaking, with some variations, the paleoenvironments of the sequence show a shallowing trend from marine upper-middle bathyal to middle neritic. These results make an important contribution to the stratigraphy and geologic history of the Cumarebo area, which is related to the Agua Salada basin, and may help clarify the paleogeography and paleotectonic evolution of this region for petroleum exploration.

  19. Wisconsinan-Holocene seismic stratigraphy of the Keathley Canyon Area and vicinity, northwestern Gulf of Mexico

    SciTech Connect

    Lee, Gwang Hoon; Bryant, W.R.; Watkins, J.S. )

    1991-03-01

    The lower continental slope of the northwestern Gulf of Mexico is characterized by a hummocky topography with shallow salt masses interspersed by numerous salt-withdrawal basins containing thick Plio-Pleistocene and older sediments. Analysis of over 7500 km of multichannel seismic reflection data from the Keathley Canyon Area and vicinity defined the Wisconsinan-Holocene sequence and its seismic facies. In interbasinal areas and in the southern part of the study area where salt is shallow, the Wisconsinan-Holocene sequence consists mainly of low-amplitude (LA) facies underlain by strong basal-reflection (SBR) facies. The LA facies occasionally show subtle onlaps against SBR facies and grade upward into a draping pattern. Onlapping LA facies are interpreted to be a lowstand systems tract deposited by widespread low-energy turbidity currents. Draping LA facies at the top may consist of hemipelagic or pelagic sediments. The SBR facies are interpreted to consist of condensed sections formed during sea-level rises and highstands. Within basins, moderate-to-high amplitude-continuous (MHC) and hummocky-to-chaotic (HC) facies occur below LA facies. The MHC facies show a pattern of flat-lying or gently dipping reflections that onlap SBR facies. Onlapping MHC facies often grade upward into a conformable pattern and are obscured by transition into LA facies. The MHC facies are interpreted as alternating coarse- and fine-grained turbidites deposited during sea-level falls and/or lowstands. The HC facies occur commonly associated with MHC facies. The HC facies may represent slope fans formed by mass-transport processes or gravity flows during sea-level falls and/or lowstands.

  20. Area contingency plan western lake Superior Coastal zone. (COTP Duluth)

    SciTech Connect

    1995-02-15

    The Area Contingency Plan, mandated under the Oil Pollution Act, was developed by the Western Lake Superior Area Committee, which is chaired by the Coast Guard and consists of local, state, federal, and private members. The plan prepares in advance for an oil or hazardous substance spill in the COTP Duluth Coastal Zone.

  1. Area contingency plan Western Lake Erie. (COTP Toledo)

    SciTech Connect

    1994-08-31

    The Area Contingency Plan, mandated under the Oil Pollution Act, was developed by the Western Lake Erie Area Committee, which is chaired by the Coast Guard and consists of local, state, federal, and private members. The plan prepares in advance for an oil or hazardous substance spill in the COTP Toledo Coastal Zone.

  2. Area contingency plan: Eastern Great Lakes. (COTP Buffalo)

    SciTech Connect

    1994-06-30

    The Area Contingency Plan, mandated under the Oil Pollution Act, was developed by the Eastern Great Lakes Area Committee, which is chaired by the Coast Guard and consists of local, state, federal, and private members. The plan prepares in advance for an oil or hazardous substance spill in the COTP Buffalo Coastal Zone.

  3. BUCKS LAKE AND CHIPS CREEK ROADLESS AREAS, CALIFORNIA.

    USGS Publications Warehouse

    Sorensen, Martin L.; Linne, J. Mitchell

    1984-01-01

    The results of a mineral-resource assessment of the Bucks Lake and Chips Creek Roadless Areas, California indicate several areas with mineral-resource potential. The presence or absence of these potentially auriferous deposits can best be determined by drilling through the relatively thin cover of volcanic rocks.

  4. Simulating Lake-Groundwater Interactions During Decadal Climate Cycles: Accounting For Variable Lake Area In The Watershed

    NASA Astrophysics Data System (ADS)

    Virdi, M. L.; Lee, T. M.

    2009-12-01

    The volume and extent of a lake within the topo-bathymetry of a watershed can change substantially during wetter and drier climate cycles, altering the interaction of the lake with the groundwater flow system. Lake Starr and other seepage lakes in the permeable sandhills of central Florida are vulnerable to climate changes as they rely exclusively on rainfall and groundwater for inflows in a setting where annual rainfall and recharge vary widely. The groundwater inflow typically arrives from a small catchment area bordering the lake. The sinkhole origin of these lakes combined with groundwater pumping from underlying aquifers further complicate groundwater interactions. Understanding the lake-groundwater interactions and their effects on lake stage over multi-decadal climate cycles is needed to manage groundwater pumping and public expectation about future lake levels. The interdependence between climate, recharge, changing lake area and the groundwater catchment pose unique challenges to simulating lake-groundwater interactions. During the 10-year study period, Lake Starr stage fluctuated more than 13 feet and the lake surface area receded and expanded from 96 acres to 148 acres over drier and wetter years that included hurricanes, two El Nino events and a La Nina event. The recently developed Unsaturated Zone Flow (UZF1) and Lake (LAK7) packages for MODFLOW-2005 were used to simulate the changing lake sizes and the extent of the groundwater catchment contributing flow to the lake. The lake area was discretized to occupy the largest surface area at the highest observed stage and then allowed to change size. Lake cells convert to land cells and receive infiltration as receding lake area exposes the underlying unsaturated zone to rainfall and recharge. The unique model conceptualization also made it possible to capture the dynamic size of the groundwater catchment contributing to lake inflows, as the surface area and volume of the lake changed during the study

  5. Lower Cretaceous Fossil Record of The Lavrasian Continental Shelf in Northwestern Turkey and Its Correlation with Surrounding Areas

    NASA Astrophysics Data System (ADS)

    Menteş, Merve; Özkar Öngen, İzver

    2015-04-01

    This study contains Zonguldak, Amasra and Kırkalerli (İğneada) area in the Northwestern Turkey. In this region, The Istanbul-Zonguldak Composite Terrane consists of two Paleozoic terranes and their Mesozoic overstep sequences around Zonguldak and Amasra. However The Istranca Terrane is characterized by a complex nappe-pile that includes metamorphic assemblages unconformably overlain by Tertiary sediments of the Thrace basin around İğneada. The original purpose of this study to analyze fossil records of Kozlu-Zonguldak, Amasra and Kırklareli (İğneada) in which Lower Cretaceous of shallow nautical sedimentary stacking which is regarding to The Lavrasian continental shelf in Northwestern Turkey. After analysing about 90 thin section and 30 samples we followed and associated lito-biostratigraphical similarities and contrasts, horizontal and vertical variation in facies which includes Orbitolina, Neotrocholina, megalospheric Rudists and various benthic foraminifera fossil records. Correlation between sections with detailed paleontological analyse wasn't presented until today, however there are several geological examination in these areas. In accordance with this purpose, this study tries to determine possible paleogeographic borders, which are in Northwestern Anatolian of The Lavrasian continental shelf, with benthic foraminiferal assemblages . In this examination, the other aim is to correlate with researches of Lower Cretaceous continental shelf of Iranian in East, Bulgaria, Romania, Italy and Spain in West, to present comparisons and contrasts in Western Pontids. Keywords: Lower Cretaceous, Benthic Foraminifera, Correlation.

  6. COUGAR LAKES-MOUNT AIX WILDERNESS STUDY AREA, WASHINGTON.

    USGS Publications Warehouse

    Simmons, George C.; Van Noy, Ronald M.

    1984-01-01

    A mineral survey of the Cougar Lakes-Mount Aix Wilderness study area in Washington was carried out to assess its mineral-resource potential. The study included reconnaissance geologic mapping and geochemical sampling, statistical analyses of samples, interpretation of an aeromagnetic survey, and an investigation of mining properties. These studies indicate that the area has a probable mineral-resource potential for silver, copper, manganese, mercury, tungsten, and zinc. This resource potential occurs in four small isolated areas in the southern half of the study area, and in a larger area which has a potential for porphyry copper, near the north boundary of the study area.

  7. Neotectonic fault structures in the Lake Thun area (Switzerland)

    NASA Astrophysics Data System (ADS)

    Fabbri, Stefano C.; Herwegh, Marco; Schlunegger, Fritz; Hübscher, Christian; Weiss, Benedikt J.; Schmelzbach, Cédric; Horstmeyer, Heinrich; Merz, Kaspar; Anselmetti, Flavio S.

    2016-04-01

    Strong historic earthquakes (i.e. intensities I0 ≥ V) in Switzerland are well documented by the earthquake catalogue of Switzerland ECOS-09 (e.g. Frutigen, 1729 AD, Mw=5.2, I0=VI). Many of these strong events can be recognized paleoseismically by large subaquatic, earthquake-triggered mass movements that occur frequently in Swiss Lakes. Some of these represent the occasional occurrence of even stronger earthquakes (i.e. Mw ˜6.5) in the Alpine region (Strasser et al., 2013), which are expected to produce noticeable surface ruptures. However, convincing evidence for Quaternary displacements with offset surface expressions have scarcely been found (e.g., Wiemer et al., 2009). Applying a multi-disciplinary approach, this study presents potential candidates for such faults in the larger Lake Thun area at the edge of the Alps. The overdeepened basin of Lake Thun is situated at the northern Alpine front, which extends orthogonally to the general strike direction of the Alpine nappe front. The northern shoreline is predominantly shaped by the front of the Subalpine Molasse, which is in strong contrast to the south western shore built by the structurally higher units of the Middle and Lower Penninic nappes. This pattern with obvious differences of both lake sides suggests a major fault along the lake axis and high tectonic activity during nappe emplacement, i.e. from Eocene times throughout the Late Miocene. The area is dominated today by a strike-slip stress regime with a slight normal faulting component (Kastrup et al., 2004). As part of a multi-disciplinary study, attempting to find potential neotectonically active fault structures in the Lake Thun area, a 2D ground penetrating radar (GPR) survey was conducted. The aim of the GPR survey was to link observations from a multichannel reflection seismic survey and a multibeam bathymetric survey carried out in Lake Thun with findings in a nearby gravel quarry revealing suspicious deformation features such as rotated gravel

  8. TIOGA LAKE, HALL NATURAL AREA, LOG CABIN-SADDLEBAG, AND HORSE MEADOWS ROADLESS AREAS, CALIFORNIA.

    USGS Publications Warehouse

    Seitz, J.F.; Federspiel, F.E.

    1984-01-01

    Studies of the geology and mineral resources of the Tioga Lake, Hall Natural Area, Log Cabin-Saddlebag, and Horse Meadows Roadless Areas in California indicate that parts of the Log Cabin-Saddlebag and Hall Natural Roadless Areas have a substantiated resource potential for gold and (or) silver resources, and a probable potential for tungsten and molybdenum resources. Tioga Lake Roadless Area has little likelihood for the occurrence of mineral resources and the Horse Meadows Roadless Area has a probable potential for low-grade tungsten, gold, and (or) silver resources. The geologic terrane in the roadless areas precludes the occurrence of organic fuel resources.

  9. 36 CFR 7.48 - Lake Mead National Recreation Area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... persons in the water or at the shoreline. (3) After December 31, 2012, no one may operate a personal.... (a) Aircraft, designated airstrips. (1)(i) The entire water surface of Lakes Mead and Mohave are... under power on those water surface areas designated as special anchorages, including fairways,...

  10. MONITORING METHODS DEVELOPMENT IN THE BEAUMONT-LAKE CHARLES AREA

    EPA Science Inventory

    In 1978, the U.S. Environmental Protection Agency initiated a study in the Beaumont, Texas-Lake Charles, Louisiana area (BLCA) as a preliminary step to develop, demonstrate and test methods for monitoring levels of chemicals, primarily in air and water, and to measure effects of ...

  11. Geophysical and geochemical studies to delineate seawater intrusion in Bagoush area, Northwestern coast, Egypt

    NASA Astrophysics Data System (ADS)

    Eissa, Mustafa A.; Mahmoud, Hussein Hosni; Shouakar-Stash, Orfan; El-Shiekh, Abdelfattah; Parker, Beth

    2016-09-01

    Coastal aquifers are the main source for sustainable freshwater in many arid and semi-arid regions around the earth. In such regions, groundwater extraction far exceeds the natural replenishment rates due to additional demands on groundwater resources especially in the last few decades. The characterization of the seawater intrusion in the Baghoush area along the northwestern coast of Egypt assesses the risk of seawater intrusion for the purpose of managing the groundwater resources in coastal areas. The (SI) in the oolitic Pleistocene aquifer is affected by several natural factors, including the drainage patterns, geological structures, distance from the sea and the manipulation of groundwater. Electrical Resistivity Tomography (ERT) has been implemented to identify the geometry of the brackish/saline water interface and to map the distribution of brackish water zone floating over the denser saline water. Seven 2-D resistivity imaging profiles were conducted using a Wenner array with different electrode distance spacings. The inverse resistivity models of these profiles indicate that these profiles are composed of three zones: the upper dry zone, the middle brackish water zone, and the lower saline water zone. The thickness of the brackish groundwater zone decreases toward the sea and the resistivity decreases with depth due to increase in water salinity. Water table along these profiles decreases from south to north, which indicates that groundwater flow is from south (inland) to north (sea). Groundwater chemistry and stable isotopes were used to determine the fresh groundwater recharge source(s), to identify mixing of different groundwaters, to evaluate seawater intrusion zone along the coast, and to investigate the upwelling of deep saline groundwater underneath the brackish zone. The recharge of fresh groundwater originates from the mountain watershed located upstream as well as the annual rainfall; however, seawater is the main source of groundwater

  12. Assessing malaria transmission in a low endemicity area of north-western Peru

    PubMed Central

    2013-01-01

    Background Where malaria endemicity is low, control programmes need increasingly sensitive tools for monitoring malaria transmission intensity (MTI) and to better define health priorities. A cross-sectional survey was conducted in a low endemicity area of the Peruvian north-western coast to assess the MTI using both molecular and serological tools. Methods Epidemiological, parasitological and serological data were collected from 2,667 individuals in three settlements of Bellavista district, in May 2010. Parasite infection was detected using microscopy and polymerase chain reaction (PCR). Antibodies to Plasmodium vivax merozoite surface protein-119 (PvMSP119) and to Plasmodium falciparum glutamate-rich protein (PfGLURP) were detected by ELISA. Risk factors for exposure to malaria (seropositivity) were assessed by multivariate survey logistic regression models. Age-specific antibody prevalence of both P. falciparum and P. vivax were analysed using a previously published catalytic conversion model based on maximum likelihood for generating seroconversion rates (SCR). Results The overall parasite prevalence by microscopy and PCR were extremely low: 0.3 and 0.9%, respectively for P. vivax, and 0 and 0.04%, respectively for P. falciparum, while seroprevalence was much higher, 13.6% for P. vivax and 9.8% for P. falciparum. Settlement, age and occupation as moto-taxi driver during previous year were significantly associated with P. falciparum exposure, while age and distance to the water drain were associated with P. vivax exposure. Likelihood ratio tests supported age seroprevalence curves with two SCR for both P. vivax and P. falciparum indicating significant changes in the MTI over time. The SCR for PfGLURP was 19-fold lower after 2002 as compared to before (λ1 = 0.022 versus λ2 = 0.431), and the SCR for PvMSP119 was four-fold higher after 2006 as compared to before (λ1 = 0.024 versus λ2 = 0.006). Conclusion Combining molecular and serological tools

  13. "Fast pedogenesis" on proglacial areas: examples from the north-western Italian Alps

    NASA Astrophysics Data System (ADS)

    D'Amico, Michele; Freppaz, Michele; Zanini, Ermanno

    2013-04-01

    Climate changes have huge impacts on alpine ecosystems. One of the most visible effects is glacial retreat since the end of the Little Ice Age (LIA: 190-190 years ago), which caused the exposure of previously glaciated surfaces. These surfaces are open-air laboratories, verifying theories regarding ecosystem and soil development. In order to increase our knowledge on the effect of time and vegetation primary succession on soil development in proglacial areas, we sampled soils and surveyed plant communities on stable points on the proglacial areas of the Lys and Verra Grande glaciers, in the Italian north-western Alps (Valle d'Aosta). Sampling sites were located on dated sites (6-260 years), on the basis of literature or historical photographs). Glacial till is attacked by weathering processes immediately after deposition and stabilization, such as loss of soluble compounds, acidification, primary mineral weathering. The speed of these processes are largely increased after the establishment of a continuous vegetation cover, thanks to surface stabilization, organic matter accumulation caused by litter input and root decomposition below the soil surface. On sialic glacial tills (Lys forefield), below timberline and under a larch - Rhododendron forest, a fast and steady decrease in pH values, increase in organic matter content and horizon differentiation were observed. In particular, genetic eluvial horizons formed in just 60 years, while diagnostic albic horizons were developed after ca. 90 years, evidencing an early start of the podzolization processes. Cheluviation of Fe and, secondarily, Al were analytically verified. However, illuviation of Fe, Al and organic matter in incipient B horizons was not sufficient to obtain diagnostic spodic horizons on LIA materials. Under grazed grassland below timberline and alpine prairie above timberline, acidification and weathering were slightly slower, and no redistribution with depth of Fe and Al oxi-hydroxides was observed. A

  14. Index for hazard of Glacier Lake Outburst flood of Lake Merzbacher by satellite-based monitoring of lake area and ice cover

    NASA Astrophysics Data System (ADS)

    Xie, Zunyi; ShangGuan, Donghui; Zhang, Shiqiang; Ding, Yongjian; Liu, Shiyin

    2013-08-01

    Previous studies show that the area of a moraine-dammed lake can provide a good indicator of the significance of its outburst. For a glacier-dammed lake however, because its area and depth fluctuates with the melting of its ice dam, it is difficult to predict the outburst of the glacier-dammed lake by using its area alone.A characteristic of the surface of Lake Merzbacher is a large amount of floating ice therefore, a method is proposed in this article to extract the area of floating ice on the lake and the area of ice free water in the lake by using Environment and Disaster Monitoring Small Satellite images respectively. Furthermore, based on the area of floating ice extracted through the image information of Lake Merzbacher in 2009 and 2010, we determined the relationship between the ice area and the outburst of the lake, then formulated the Index for hazard of Glacier Lake Outburst Flood (IGLOF) of Lake Merzbacher, which cannot only predict the flood outburst, but also determine the specific outburst period after the lake drainage had occurred. This can be shown in a recalculation of the lake drainages in the years 2009 and 2010. Research results indicate that when IGLOF is less than 0.5 and the lake area is larger than 3 km2, the outburst process is in early-warning period and GLOF will occur in the next 5-8 days. Also, the successful outburst prediction of Lake Merzbacher in 2011 showed that the index described in this paper provides a quick methodology for forecasting and warning against Lake Merzbacher outburst floods. However,as our research was based on a short observation period (2009-2011) and also cannot be supplemented by other images, it will still be needed to be checked and validated by continuous observation and improvement in future.

  15. The role of anthropogenic and natural factors in shaping the geochemical evolution of groundwater in the Subei Lake basin, Ordos energy base, Northwestern China.

    PubMed

    Liu, Fei; Song, Xianfang; Yang, Lihu; Han, Dongmei; Zhang, Yinghua; Ma, Ying; Bu, Hongmei

    2015-12-15

    Groundwater resources are increasingly exploited for industrial and agricultural purposes in many arid regions globally, it is urgent to gain the impact of the enhanced anthropogenic pressure on the groundwater chemistry. The aim of this study was to acquire a comprehensive understanding of the evolution of groundwater chemistry and to identify the impact of natural and anthropogenic factors on the groundwater chemistry in the Subei Lake basin, Northwestern China. A total of 153 groundwater samples were collected and major ions were measured during the three campaigns (August and December 2013, May 2014). At present, the major hydrochemical facies in unconfined groundwater are Ca-Mg-HCO3, Ca-Na-HCO3, Na-Ca-HCO3, Na-HCO3, Ca-Mg-SO4 and Na-SO4-Cl types, while the main hydrochemical facies in confined groundwater are Ca-Mg-HCO3, Ca-Na-HCO3, Na-Ca-HCO3, Ca-HCO3 and Na-HCO3 types. Relatively greater seasonal variation can be observed in the chemical constituents of confined groundwater than that of unconfined groundwater. Rock weathering predominates the evolution of groundwater chemistry in conjunction with the cation exchange, and the dissolution/precipitation of gypsum, halite, feldspar, calcite and dolomite are responsible for the chemical constituents of groundwater. Anthropogenic activities can be classified as: (1) groundwater overexploitation; (2) excessive application of fertilizers in agricultural areas. Due to intensive groundwater pumping, the accelerated groundwater mineralization resulted in the local changes in hydrochemical facies of unconfined groundwater, while the strong mixture, especially a large influx of downward leakage from the unconfined aquifer into the confined aquifer, played a vital role in the fundamental variation of hydrochemical facies in confined aquifer. The nitrate contamination is mainly controlled by the local hydrogeological settings coupled with the traditional flood irrigation. The deeper insight into geochemical evolution of

  16. Multibeam mapping of selected areas of the outer continental shelf, northwestern Gulf of Mexico; data, images, and GIS

    USGS Publications Warehouse

    Gardner, James V.; Beaudoin, Jonathan D.; Hughes-Clarke, John E.; Dartnell, Peter

    2002-01-01

    Following the publication of high-resolution (5-meter spatial resolution) multibeam echosounder (MBES) images of the Flower Garden Banks National Marine Sanctuary area of the northwestern Gulf of Mexico (Gardner et al., 1998), the Flower Garden Banks National Marine Sanctuary (FGBNMS) and the Minerals Management Service (MMS) have been interested in additional MBES data in the area. A coalition of FGBNMS, MMS, and the U.S. Geological Survey (USGS) was formed to map additional areas of interest in the northwestern Gulf of Mexico (fig. 1) in 2002. FGBNMS chose the survey areas, and the USGS chose the MBES. MMS and FGBNMS funded the mapping, and the USGS organized the ship and multibeam systems through a cooperative agreement between the USGS and the University of New Brunswick. The objective of the cruise was to map 12 regions of interest to MMS and the FGBNMS, including Alderdice, Sonnier, Geyer, Bright, Rankin (1 and 2), Jakkula, McNeil, Bouma, McGrail, Rezak, and Sidner Banks.

  17. A new species of Cordyligaster Macquart, reared from caterpillars in Area de Conservacion Guanacaste, northwestern Costa Rica

    PubMed Central

    Wood, D Monty; Smith, M Alex; Janzen, Daniel; Hallwachs, Winnie

    2014-01-01

    Abstract We describe a new species of Cordyligaster Macquart (Diptera: Tachinidae) from Area de Conservacion Guanacaste (ACG) in northwestern Costa Rica. Cordyligaster capellii sp. n., is described and photographed. All specimens of C. capellii were reared from Syngamia florella (Stoll, 1781) (Lepidoptera, Crambidae, Spilomelinae), a leaf-rolling caterpillar collected in ACG rain forest. By coupling morphology, photographic documentation, life history and molecular data, we provide a clear and concise description of this new species. In addition the authors provide new distribution and host records for C. fuscipennis (Macquart) reared in ACG. PMID:25535485

  18. 33 CFR 334.520 - Lake George, Fla.; naval bombing area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Lake George, Fla.; naval bombing... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.520 Lake George, Fla.; naval bombing area. (a) The danger zone. An area in the eastern part of Lake George described as...

  19. 33 CFR 165.1171 - Copper Canyon, Lake Havasu, Colorado River-Regulated Navigation Area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Copper Canyon, Lake Havasu... Guard District § 165.1171 Copper Canyon, Lake Havasu, Colorado River—Regulated Navigation Area. (a) Location. The following is a regulated navigation area: (1) In the water area of Copper Canyon, Lake...

  20. 33 CFR 165.1171 - Copper Canyon, Lake Havasu, Colorado River-Regulated Navigation Area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Copper Canyon, Lake Havasu... Guard District § 165.1171 Copper Canyon, Lake Havasu, Colorado River—Regulated Navigation Area. (a) Location. The following is a regulated navigation area: (1) In the water area of Copper Canyon, Lake...

  1. 33 CFR 334.520 - Lake George, Fla.; naval bombing area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Lake George, Fla.; naval bombing... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.520 Lake George, Fla.; naval bombing area. (a) The danger zone. An area in the eastern part of Lake George described as...

  2. 33 CFR 334.520 - Lake George, Fla.; naval bombing area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Lake George, Fla.; naval bombing... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.520 Lake George, Fla.; naval bombing area. (a) The danger zone. An area in the eastern part of Lake George described as...

  3. 33 CFR 165.1171 - Copper Canyon, Lake Havasu, Colorado River-Regulated Navigation Area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Copper Canyon, Lake Havasu... Guard District § 165.1171 Copper Canyon, Lake Havasu, Colorado River—Regulated Navigation Area. (a) Location. The following is a regulated navigation area: (1) In the water area of Copper Canyon, Lake...

  4. 33 CFR 334.520 - Lake George, Fla.; naval bombing area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Lake George, Fla.; naval bombing... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.520 Lake George, Fla.; naval bombing area. (a) The danger zone. An area in the eastern part of Lake George described as...

  5. 33 CFR 165.1171 - Copper Canyon, Lake Havasu, Colorado River-Regulated Navigation Area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Copper Canyon, Lake Havasu... Guard District § 165.1171 Copper Canyon, Lake Havasu, Colorado River—Regulated Navigation Area. (a) Location. The following is a regulated navigation area: (1) In the water area of Copper Canyon, Lake...

  6. 33 CFR 165.1171 - Copper Canyon, Lake Havasu, Colorado River-Regulated Navigation Area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Copper Canyon, Lake Havasu... Guard District § 165.1171 Copper Canyon, Lake Havasu, Colorado River—Regulated Navigation Area. (a) Location. The following is a regulated navigation area: (1) In the water area of Copper Canyon, Lake...

  7. 33 CFR 334.520 - Lake George, Fla.; naval bombing area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Lake George, Fla.; naval bombing... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.520 Lake George, Fla.; naval bombing area. (a) The danger zone. An area in the eastern part of Lake George described as...

  8. 75 FR 5115 - Temporary Concession Contract for Lake Mead National Recreation Area, AZ/NV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-01

    ... concession contract for Lake Mead National Recreation Area. SUMMARY: Pursuant to 36 CFR 51.24, public notice... National Park Service Temporary Concession Contract for Lake Mead National Recreation Area, AZ/NV AGENCY... the conduct of certain visitor services within Lake Mead National Recreation Area, Arizona and...

  9. VITELLOGENIN GENE EXPRESSION IN FATHEAD MINNOWS EXPOSED TO EE2 IN A WHOLE LAKE DOSING EXPERIMENT

    EPA Science Inventory

    A whole-lake endocrine disruption experiment was conducted by Fisheries and Oceans Canada at the Experimental Lakes Area (ELA), northwestern Ontario in 2001 and 2002. This experiment examined population, organism, biochemical and cellular-level effects in lake trout, white sucke...

  10. Glacial lakes in the Indian Himalayas--from an area-wide glacial lake inventory to on-site and modeling based risk assessment of critical glacial lakes.

    PubMed

    Worni, Raphael; Huggel, Christian; Stoffel, Markus

    2013-12-01

    Glacial lake hazards and glacial lake distributions are investigated in many glaciated regions of the world, but comparably little attention has been given to these topics in the Indian Himalayas. In this study we present a first area-wide glacial lake inventory, including a qualitative classification at 251 glacial lakes >0.01 km(2). Lakes were detected in the five states spanning the Indian Himalayas, and lake distribution pattern and lake characteristics were found to differ significantly between regions. Three glacial lakes, from different geographic and climatic regions within the Indian Himalayas were then selected for a detailed risk assessment. Lake outburst probability, potential outburst magnitudes and associated damage were evaluated on the basis of high-resolution satellite imagery, field assessments and through the use of a dynamic model. The glacial lakes analyzed in the states of Jammu and Kashmir and Himachal Pradesh were found to present moderate risks to downstream villages, whereas the lake in Sikkim severely threatens downstream locations. At the study site in Sikkim, a dam breach could trigger drainage of ca. 16×10(6)m(3) water and generate maximum lake discharge of nearly 7000 m(3) s(-). The identification of critical glacial lakes in the Indian Himalayas and the detailed risk assessments at three specific sites allow prioritizing further investigations and help in the definition of risk reduction actions. PMID:23218457

  11. Analysis and mitigation of remote geohazards in high mountain areas of Tajikistan with special emphasis on glacial lake outburst floods

    NASA Astrophysics Data System (ADS)

    Schneider, Jean F.; Mergili, Martin; Schneider, Demian

    2010-05-01

    downstream. Most of these lakes are dammed by moraines containing some ice. A significant example for a lake dammed by a rock glacier is located in the Central Pamir. Currently, the dam appears stable, but further melting of the ice could lead to a progressive failure. In the highest portions of the Pamir, glacial retreat and the development of glacial lakes has not yet reached the stage as observed farther South. However, future retreat, but also surging of glaciers in the area may result in new lakes. The Alai Mountains in North-western Tajikistan have experienced comparable processes in the past. However, damming of lakes by rainfall-triggered landslides has still been reported repeatedly. Two major tectonic faults run through the territory of Tajikistan, allowing earthquake magnitudes of 7.5 and more. Whilst dams may be weakened by earthquakes, or flood waves may be generated by rock falls into the lakes, several lakes dammed by earthquake-triggered landslides do exist or have broken out. It is certain that new lakes of this type will develop in the future, but the size and exact location are hard to predict. Targeted and well-planned mitigation measures are required to prevent that future remote geohazard events will evolve into disasters, or at least to reduce the magnitude of the disaster. This requires conversion of the knowledge gained during the assessment into strategies and procedures for reducing the risk, e.g. promoting the awareness and preparedness, initiating monitoring and technical measures, and installing emergency information systems. In order to enable the realization of all these activities, much emphasis was put on capacity-building of the local actors: all the relevant agencies, scientists, and stakeholders were involved already in the hazard assessment, and specific training workshops were carried out.

  12. Hot Dry Rock resources of the Clear Lake area, California

    SciTech Connect

    Burns, K.L.; Potter, R.M.; Peake, R.A.

    1995-01-01

    The Hot Dry Rock resources of the Clear Lake area of northern California are hot, large and areally uniform. The geological situation is special, probably overlying a slabless window caused by interaction between tectonic plates. Consequent magmatic processes have created a high-grade resource, in which the 300{degree}C isotherm is continuous, subhorizontal, and available at the shallow depth of 2.4 to 4.7 km over an area of 800 km{sup 2}. The region is very favorable for HDR development.

  13. 78 FR 29696 - Proposed Flood Elevation Determinations for Lake County, Illinois, and Incorporated Areas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-21

    ... Lake County, Illinois, and Incorporated Areas AGENCY: Federal Emergency Management Agency, DHS. ACTION... proposed rule concerning proposed flood elevation determinations for Lake County, Illinois, and... rulemaking at 76 FR 39063, proposing flood elevation determinations along one or more flooding sources...

  14. Diversity and Composition of Bacterial Community in Soils and Lake Sediments from an Arctic Lake Area.

    PubMed

    Wang, Neng Fei; Zhang, Tao; Yang, Xiao; Wang, Shuang; Yu, Yong; Dong, Long Long; Guo, Yu Dong; Ma, Yong Xing; Zang, Jia Ye

    2016-01-01

    This study assessed the diversity and composition of bacterial communities within soils and lake sediments from an Arctic lake area (London Island, Svalbard). A total of 2,987 operational taxonomic units were identified by high-throughput sequencing, targeting bacterial 16S rRNA gene. The samples from four sites (three samples in each site) were significantly different in geochemical properties and bacterial community composition. Proteobacteria and Acidobacteria were abundant phyla in the nine soil samples, whereas Proteobacteria and Bacteroidetes were abundant phyla in the three sediment samples. Furthermore, Actinobacteria, Chlorobi, Chloroflexi, Elusimicrobia, Firmicutes, Gemmatimonadetes, Nitrospirae, Planctomycetes, Proteobacteria significantly varied in their abundance among the four sampling sites. Additionally, members of the dominant genera, such as Clostridium, Luteolibacter, Methylibium, Rhodococcus, and Rhodoplanes, were significantly different in their abundance among the four sampling sites. Besides, distance-based redundancy analysis revealed that pH (p < 0.001), water content (p < 0.01), ammonium nitrogen ([Formula: see text]-N, p < 0.01), silicate silicon ([Formula: see text]-Si, p < 0.01), nitrite nitrogen ([Formula: see text]-N, p < 0.05), organic carbon (p < 0.05), and organic nitrogen (p < 0.05) were the most significant factors that correlated with the bacterial community composition. The results suggest soils and sediments from a lake area in the Arctic harbor a high diversity of bacterial communities, which are influenced by many geochemical factors of Arctic environments. PMID:27516761

  15. Diversity and Composition of Bacterial Community in Soils and Lake Sediments from an Arctic Lake Area

    PubMed Central

    Wang, Neng Fei; Zhang, Tao; Yang, Xiao; Wang, Shuang; Yu, Yong; Dong, Long Long; Guo, Yu Dong; Ma, Yong Xing; Zang, Jia Ye

    2016-01-01

    This study assessed the diversity and composition of bacterial communities within soils and lake sediments from an Arctic lake area (London Island, Svalbard). A total of 2,987 operational taxonomic units were identified by high-throughput sequencing, targeting bacterial 16S rRNA gene. The samples from four sites (three samples in each site) were significantly different in geochemical properties and bacterial community composition. Proteobacteria and Acidobacteria were abundant phyla in the nine soil samples, whereas Proteobacteria and Bacteroidetes were abundant phyla in the three sediment samples. Furthermore, Actinobacteria, Chlorobi, Chloroflexi, Elusimicrobia, Firmicutes, Gemmatimonadetes, Nitrospirae, Planctomycetes, Proteobacteria significantly varied in their abundance among the four sampling sites. Additionally, members of the dominant genera, such as Clostridium, Luteolibacter, Methylibium, Rhodococcus, and Rhodoplanes, were significantly different in their abundance among the four sampling sites. Besides, distance-based redundancy analysis revealed that pH (p < 0.001), water content (p < 0.01), ammonium nitrogen (NH4+-N, p < 0.01), silicate silicon (SiO42--Si, p < 0.01), nitrite nitrogen (NO2--N, p < 0.05), organic carbon (p < 0.05), and organic nitrogen (p < 0.05) were the most significant factors that correlated with the bacterial community composition. The results suggest soils and sediments from a lake area in the Arctic harbor a high diversity of bacterial communities, which are influenced by many geochemical factors of Arctic environments. PMID:27516761

  16. Does pH affect fish species richness when lake area is considered?

    USGS Publications Warehouse

    Rago, P.J.; Wiener, J.G.

    1986-01-01

    Numerous surveys have shown that fish species richness (number of species) is positively correlated with lake pH. However, species richness of fish communities is also correlated with lake size, and low-pH lakes are often small. Thus, conclusions drawn from examination of fish community structure relative to spatial (among- lake) variation in pH have been limited by uncertainties regarding the confounded effects of lake area. The authors used two statistical methods, analysis of covariance and a nonparametric blocked comparison test, to remove effects of lake area and compare fish species richness in low-pH and high-pH lakes. Data from six previous surveys of water chemistry and fish communities in lakes of Ontario and northern Wisconsin were examined. Lakes with low pH ( less than or equal to 6.0) contained significantly fewer fish species than lakes with high pH (> 6.0) when the effect of lake area was considered. A simple probabilistic model showed that the ability to detect differences in species richness is low when lake areas and the pool of potential colonizing species are small. The authors recommend the blocked comparison test for separating the effects of lake area and pH on species richness.

  17. Identifying the origin and geochemical evolution of groundwater using hydrochemistry and stable isotopes in the Subei Lake basin, Ordos energy base, Northwestern China

    NASA Astrophysics Data System (ADS)

    Liu, F.; Song, X.; Yang, L.; Zhang, Y.; Han, D.; Ma, Y.; Bu, H.

    2015-01-01

    . Comparison of the regression line for δ18O and δD showed that lake water in the Subei Lake basin contains more heavily isotopic composition than that in the Habor Lake basin, indicating that lake water in the discharge area has undergone stronger evaporation than lake water in the recharge area. Hydrochemical and isotopic information of utmost importance has been provided to decision makers by the present study so that a sustainable groundwater management strategy can be designed for the Ordos energy base.

  18. MOLECULAR, PROTEIN AND HISTOLOGICAL INDICATORS IN FATHEAD MINNOWS EXPOSEDF TO EE2 IN A WHOLE-LAKE DOSING EXPERIMENT

    EPA Science Inventory

    A whole-lake endocrine disruption experiment was conducted by Fisheries and Oceans Canada at the Experimental Lakes Area (ELA), northwestern Ontario from 2001 to 2003. This experiment examined population, organism, biochemical and cellular-level effects in lake trout, white suck...

  19. Physical and Hydrochemical Evidence of Lake Leakage and Assessment of Karst Features in the Vicinity of Lake Seminole, Southwestern Georgia and Northwestern Florida

    NASA Astrophysics Data System (ADS)

    Crilley, D. M.; Torak, L. J.

    2002-12-01

    Lake Seminole is the surface manifestation of an interconnected aquifer-stream-reservoir system characterized by a constructed impoundment emplaced in the karst terrain of the lower Apalachicola-Chattahoochee-Flint River Basin. Physical, chemical, and isotopic constituents of water samples indicate surface water mixing with ground water of the underlying Upper Floridan aquifer, lake leakage beneath Jim Woodruff Dam, and karstic dissolution of the limestone aquifer matrix. Major ions, nutrients, radon 222, and stable isotopes of hydrogen and oxygen collected in 2000 from 30 wells, 7 lake locations, and 5 springs indicate that in-lake springflow evolves chemically and isotopically along ground-water and surface-water pathways. Although mixing ratios of ground water to surface water in springs varied with location and season, springflow from May to October exhibited more ground-water-like qualities (higher specific conductance, dissolved oxygen, and lower temperature) than surface water. Ratios from November to April were difficult to quantify due to rapid mixing of spring and lake water during sampling and reduced flow from springs. Lake leakage is evidenced in the bottom of the Apalachicola River about 300 yards downstream of the dam, where lake water "boils" up from a limestone ledge at rates of about 140-220 cubic feet per second. Dye tracing by the U.S. Army Corps of Engineers indicates that the river boil also receives water from a similar boil on land, which discharges to a sinkhole adjacent to the river. Isotopic data indicate about a 13 to 1 mixing ratio of lake water to ground water. Calcite saturation indices of ground-water samples indicate a higher potential for karstic dissolution from late fall through early spring than in the summer. The relatively short residence time (5-7 hours) and rapid flow velocity (nearly 500 feet per hour) for lake water to leak into the aquifer and exit at the boil suggests that this water would not reach equilibrium while in

  20. A Combined Molecular and Isotopic Study of Anoxygenic Photosynthesis in Meromictic Lakes of the Northwestern United States

    NASA Astrophysics Data System (ADS)

    Harris, J. H., IV; Gilhooly, W., III; Crane, E. J., III; Steinman, B.; Shelton, M. R.

    2014-12-01

    Sulfur isotope fractionations within the chemocline can be an indication of green and purple sulfur photosynthetic activity. This isotopic signal is, however, small and variable, on the order of +2-6‰ (Zerkle et al. 2009). It is therefore advantageous to investigate the environmental and ecological effects on this signal so that these influences can be taken into account when estimating the contribution of anoxygenic phototrophs to the sulfur cycle in aquatic environments. This project aims to investigate the ways in which anoxygenic phototroph community structure and lake water geochemistry impact the sulfur isotope fractionation expressed during anoxygenic photosynthesis in meromictic lakes. During the summer of 2013, water column profile analysis of six lakes in the Pacific Northwest (located in eastern Washington and western Montana) were conducted to assess photosynthetically available radiation, salinity, pH, temperature, dissolved solids, and specific conductivity. Water column samples were obtained to determine the sulfur isotopic composition of dissolved sulfate and sulfide, major ion and sulfide concentrations. Microbial samples were also collected for genetic sequencing. Initial results found green (e.g., Chlorobiaceae sp.) and purple (e.g., Lamprocystis purpurea) bacteria at the same depth in one of the study lakes. These data, in addition to the same suite of samples collected in the summer of 2014, provide insight into relationships between the isotopic composition of sulfur (in H2S, S0, and SO4), lake water chemistry, and the presence or absence of green and purple sulfur bacteria.

  1. Results of geomorphologic interpretation of the bed relief in the subglacial Lake Vostok area

    NASA Astrophysics Data System (ADS)

    Popov, S. V.; Lastochkin, A. N.; Popkov, A. M.; Masolov, V. N.; Lukin, V. V.

    2002-05-01

    Ground-based reflection seismic and radio echo sounding investigations in the vicinity of subglacial Lake Vostok undertaken for the last seven years by PMGRE in the framework of RAE have allowed us to collect information regarding the morphology of its bottom and slopes providing some understanding of the geomorphologic features of this area of East Antarctica. First attempts of the bed relief geomorphologic interpretation were made based on the aforementioned data. These results will be presented at the meeting. The detailed data are reveals a complex morphology of the relief. Directly beneath the Russian Vostok station there is an asymmetrical bathymetry. The principal structure of the area is a U-shaped Vostok valley. It is approximately 280 km long in the south-north direction and more than 2000 m deep. Eastern and western parts of the territory are higher compared to the southern and northern ones. The relief is more dissected elevating over more than approximately 600 m a.s.l. The smoothed lowland with a height approximately 200 m b.s.l. dominates the north-western part. It is complicated by a rise, which is located along the valley slope. The saddles of smaller valleys are parallel and orthogonal to the Vostok depression. The hillocky landscape with a 200 m height b.s.l occupies the south-western and south-eastern areas. The latter is complicated by ridges with a range of approximately 50 m oriented north-southward. An analysis of the bed relief lineaments suggests that the slopes of the valley could be confined to deep tectonic faults. Its predominant direction is north-southward and diagonal.

  2. Western Stump Lake, a major canvasback staging area in eastern North Dakota

    USGS Publications Warehouse

    Kantrud, H.A.

    1986-01-01

    Large numbers of waterfowl, especially canvasback (Aythya valisineria), used Western Stump Lake as a staging area during most of October 1985. Selection of the lake as a conditioning site by this species likely is caused by extensive, shallow-water beds of sago pondweed (Potamogeton pectinatus) and lack of human disturbance. A brief limnological and historical account of the lake is provided.

  3. 33 CFR 162.210 - Lake Tahoe, Calif.; restricted areas along south shore.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... south 300 feet to the high waterline. (4) El Dorado County Beach. The waters of Lake Tahoe shoreward of... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Lake Tahoe, Calif.; restricted... § 162.210 Lake Tahoe, Calif.; restricted areas along south shore. (a) The areas—(1) Baldwin Beach,...

  4. 33 CFR 162.210 - Lake Tahoe, Calif.; restricted areas along south shore.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... south 300 feet to the high waterline. (4) El Dorado County Beach. The waters of Lake Tahoe shoreward of... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Lake Tahoe, Calif.; restricted... § 162.210 Lake Tahoe, Calif.; restricted areas along south shore. (a) The areas—(1) Baldwin Beach,...

  5. 33 CFR 162.210 - Lake Tahoe, Calif.; restricted areas along south shore.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... south 300 feet to the high waterline. (4) El Dorado County Beach. The waters of Lake Tahoe shoreward of... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Lake Tahoe, Calif.; restricted... § 162.210 Lake Tahoe, Calif.; restricted areas along south shore. (a) The areas—(1) Baldwin Beach,...

  6. 33 CFR 162.210 - Lake Tahoe, Calif.; restricted areas along south shore.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... south 300 feet to the high waterline. (4) El Dorado County Beach. The waters of Lake Tahoe shoreward of... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Lake Tahoe, Calif.; restricted... § 162.210 Lake Tahoe, Calif.; restricted areas along south shore. (a) The areas—(1) Baldwin Beach,...

  7. 33 CFR 162.210 - Lake Tahoe, Calif.; restricted areas along south shore.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... south 300 feet to the high waterline. (4) El Dorado County Beach. The waters of Lake Tahoe shoreward of... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Lake Tahoe, Calif.; restricted... § 162.210 Lake Tahoe, Calif.; restricted areas along south shore. (a) The areas—(1) Baldwin Beach,...

  8. [Discussion on water conservancy projects and schistosomiasis control in Poyang Lake area].

    PubMed

    Liu, Dao-Nan

    2013-02-01

    According to the schistosomiasis endemic situation in the Poyang Lake area, this paper analyzes the relationship between the water conservancy projects and schistosomiasis control, and reviews and discusses the effects of the Water Level Control Project of Poyang Lake, the Lake Dike Slope Hardening Project, and the Lifting Delta and Descending Beach Project on Oncomelania snail control. PMID:23687826

  9. Aeromagnetic interpretation and mineral investigations in the Ezine, Canakkale-Karabiga, Marmara, and Kapidag areas of northwestern Turkey

    USGS Publications Warehouse

    Jacobson, Herbert Samuel; Ozelci, F.; Yazgan, Durmaz; Hatay, N.; Karahacioglu, Hamit

    1972-01-01

    Aeromagnetic surveys and mineral investigations are planned or in progress in ten areas of northwestern Turkey (fig. 1). This report reviews results obtained from August 1967 to January 1, 1968, through aeromagnetic interpretation and field investigations in four of the areas (Areas 2, 3,4, and 5). Aeromagnetic interpretation identified 27 prominent anomalies, 17 of which were checked in the field. The majority of these anomalies were found to be caused by minor amounts of magnetite in igneous rocks, including granite stocks, mafic flows, and mafic dikes. Other anomalies are caused by magnetite in metamorphic rocks or by topographic effects. However, massive magnetite boulders were observed in three adjoining localities (Anomalies E2, E3, and E4, fig. 2) in area 2, and magnetite partly replacing a limestone boulder was found in area 3 (Anomaly CK3, fig. 3). Further study of these magnetite exposures is planned. In addition, two iron prospects and one lead prospect were briefly examined. All the prospects were considered small and not worthy of further study at this time.

  10. Groundwater-Lake Interaction in the Dead Sea Area

    NASA Astrophysics Data System (ADS)

    Kiro, Y.; Weinstein, Y.; Starinsky, A.; Yechieli, Y.

    2011-12-01

    The Dead Sea hypersaline water system is unique in terms of its unusual geochemical composition, rapid lake level changes and water composition of the brines discharging along its shoreline. The Dead Sea can be used as a natural lab for studying groundwater-seawater interaction and saline water hydrological circulation along the aquifer-sea boundary. It provides an opportunity to follow the geochemical processes along a flow path from the lake into the aquifer and back into the lake. The lake level has been dropping since the 1960's due to human interference in its water budget, reaching a rate of 1 m/yr in recent years. Saline water circulation in coastal aquifers may be a major process that governs trace element mass balances in coastal areas. This study uses radium isotopes in order to quantify the lake water circulation in the Dead Sea aquifer. There are four naturally-occurring radium isotopes, with half-lives ranging from 3.7 days to 1600 years which are chain products of uranium and thorium isotopes. Radium isotopes are usually enriched in saline groundwater and therefore are good candidates for estimating seawater or hypersaline lake water circulation in the aquifer. Compared to most natural water bodies, the Dead Sea is extremely enriched in radium and barium, where both 226Ra and 228Ra activities and Ba concentration (145, 1-2 dpm/L and 5 mg/L, respectively) are 2-3 orders of magnitude higher than in ocean water, whereas the salinity of the Dead Sea is only 10 times higher. Circulated Dead Sea water in the aquifer contains decreased concentrations of 226Ra (60 dpm/L), Ba (1.5 mg/L), Sr (300 relative to 340 mg/L in the Dead Sea) and Sulfate (250 relative to 392 mg/L). We suggest that the low 226Ra and Ba concentrations are due to precipitation of barite and celestine from the supersaturated Dead Sea water on entering the aquifer. 228Ra and the shorter-lived 224Ra and 223Ra, which have much lower activities in the Dead Sea (up to 1.8, 3 and 0.8 dpm

  11. Chemistry of lakes in designated wilderness areas in the western United States.

    PubMed

    Eilers, J M; Brakke, D F; Landers, D H; Overton, W S

    1989-04-01

    A synoptic survey of 719 lakes representing an estimated 10,393 lakes in mountainous areas of the western United States was conducted in autumn 1985. Nearly two-thirds of the study lakes were located in wilderness areas or national parks and were sampled by ground access. The results of a comparability study of 45 wilderness lakes accessed by helicopter and ground crews indicated that the data were generally indistinguishable, making it possible to use data from lakes sampled by ground crews without modification. Wilderness lakes had lower acid neutralizing capacity (ANC), base cations, sulfate, and dissolved organic carbon than nonwilderness lakes throughout the West. The highest estimated number (849) and percentage (42.1) of low ANC (≤50 μeq L(-1)) wilderness lakes were located in California; the lowest number (66) was located in the Southern Rockies. The Sierra Nevada contained an estimated 808 low ANC lakes, representing the largest subpopulation of low ANC lakes associated with an individual mountain range in the West. Wilderness lakes in selected geographic areas of the Rocky Mountains generally contained higher concentrations of major ions than lakes in the far West and the concentrations generally increased from the Northern to the Southern Rockies. Comparison of wilderness lakes in the West with lakes in the Adirondack Park, New York, and the Boundary Waters Canoe Area/Voyagers National Park in Northeastern Minnesota showed that western lakes are highly sensitive resources that currently exhibit little evidence of anthropogenic acidification. Although wilderness lakes do not exhibit symptoms of chronic acidification, short-term depression of pH and ANC from snowmelt and thunderstorms occur and episodic acidification influenced by anthropogenic sources cannot be discounted on the basis of this survey. PMID:24249054

  12. Review of Apanteles sensu stricto (Hymenoptera: Braconidae, Microgastrinae) from Area de Conservación Guanacaste, northwestern Costa Rica, with keys to all described species from Mesoamerica

    Technology Transfer Automated Retrieval System (TEKTRAN)

    More than half a million specimens of wild-caught Lepidoptera caterpillars have been reared for their parasitoids, identification, and DNA barcoding over a period of 34 years (and ongoing) from Area de Conservación de Guanacaste (ACG), northwestern Costa Rica. This provides the world’s best place-ba...

  13. Role of the Lakes in Groundwater Recharge and Discharge in the Young Glacial Area, Northern Poland.

    PubMed

    Jaworska-Szulc, Beata

    2016-07-01

    The aim of this research was to delineate characteristic hydrogeological lake types in the Young Glacial Area (YGA). The YGA is in the central and east part of the Kashubian Lake District (KLD) in Northern Poland, an area covered by deposits of Quaternary glaciation. All the bigger lakes were investigated in the area of about 1500 km(2) (39 lakes). The role of lakes in groundwater recharge and discharge was determined from total dissolved solids (TDS) in lake waters and also from groundwater flow simulation. The general trend was that gaining lakes, as determined by flow modeling, had higher values of TDS than losing lakes. In addition to typical gaining lakes (with TDS > 250 mg/l), there were losing lakes perched on glacial till deposits with very low TDS (<100 mg/l). Two groups of losing lakes were delineated: ones with very low TDS and another group with slightly higher TDS (due to local contact with groundwater). Flow-through lakes with TDS of 170-200 mg/l were also delineated. PMID:26619113

  14. Monitoring the Presence of 13 Active Compounds in Surface Water Collected from Rural Areas in Northwestern Spain

    PubMed Central

    Iglesias, Alejandra; Nebot, Carolina; Vázquez, Beatriz I.; Coronel-Olivares, Claudia; Franco Abuín, Carlos M.; Cepeda, Alberto

    2014-01-01

    Drug residues are considered environmental contaminants, and their occurrence has recently become a matter of concern. Analytical methods and monitoring systems are therefore required to control the continuous input of these drug residues into the environment. This article presents a suitable HPLC-ESI-MS/MS method for the simultaneous extraction, detection and quantification of residues of 13 drugs (antimicrobials, glucocorticosteroids, anti-inflammatories, anti-hypertensives, anti-cancer drugs and triphenylmethane dyes) in surface water. A monitoring study with 549 water samples was carried out in northwestern Spain to detect the presence of drug residues over two sampling periods during 2010, 2011 and 2012. Samples were collected from rural areas with and without farming activity and from urban areas. The 13 analytes were detected, and 18% of the samples collected showed positive results for the presence of at least one analyte. More collection sites were located in rural areas than in urban areas. However, more positive samples with higher concentrations and a larger number of analytes were detected in samples collected from sites located after the discharge of a WWTP. Results indicated that the WWTPs seems to act as a concentration point. Positive samples were also detected at a site located near a drinking water treatment plant. PMID:24837665

  15. 33 CFR 162.215 - Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. 162.215 Section 162.215 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 162.215 Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. (a) The restricted area....

  16. 33 CFR 162.215 - Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. 162.215 Section 162.215 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 162.215 Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. (a) The restricted area....

  17. 33 CFR 162.215 - Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. 162.215 Section 162.215 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 162.215 Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. (a) The restricted area....

  18. 33 CFR 162.215 - Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. 162.215 Section 162.215 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 162.215 Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. (a) The restricted area....

  19. 33 CFR 162.215 - Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. 162.215 Section 162.215 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 162.215 Lake Tahoe, Nev.; restricted area adjacent to Nevada Beach. (a) The restricted area....

  20. Delayed Response of Lake Area Change to Climate Change in Siling Co Lake, Tibetan Plateau, from 2003 to 2013.

    PubMed

    Yi, Guihua; Zhang, Tingbin

    2015-11-01

    The Tibetan Plateau is a key area for research on global environmental changes. During the past 50 years, the climate in the Siling Co lake area has become continuously warmer and wetter, which may have further caused the increase in Siling Co lake area. Based on the Siling Co lake area (2003 to 2013) and climate data acquired from the Xainza and Baingoin meteorological stations (covering 1966 to 2013), we analyzed the delayed responses of lake area changes to climate changes through grey relational analysis. The following results were obtained: (1) The Siling Co lake area exhibited a rapid expansion trend from 2003 to 2013. The lake area increased to 2318 km², with a growth ratio of 14.6% and an annual growth rate of 26.84 km²·year(-1); (2) The rate of air temperature increase was different in the different seasons. The rate in the cold season was about 0.41 °C per ten years and 0.32 °C in hot season. Precipitation evidently increased, with a change rate of 17.70 mm per ten years in the hot season and a slight increase with a change rate of 2.36 mm per ten years in the cold season. Pan evaporation exhibited evidently decreasing trends in both the hot and cold seasons, with rates of -33.35 and -14.84 mm per ten years, respectively; (3) An evident delayed response of lake area change to climate change is observed, with a delay time of approximately one to two years. PMID:26528996

  1. Delayed Response of Lake Area Change to Climate Change in Siling Co Lake, Tibetan Plateau, from 2003 to 2013

    PubMed Central

    Yi, Guihua; Zhang, Tingbin

    2015-01-01

    The Tibetan Plateau is a key area for research on global environmental changes. During the past 50 years, the climate in the Siling Co lake area has become continuously warmer and wetter, which may have further caused the increase in Siling Co lake area. Based on the Siling Co lake area (2003 to 2013) and climate data acquired from the Xainza and Baingoin meteorological stations (covering 1966 to 2013), we analyzed the delayed responses of lake area changes to climate changes through grey relational analysis. The following results were obtained: (1) The Siling Co lake area exhibited a rapid expansion trend from 2003 to 2013. The lake area increased to 2318 km2, with a growth ratio of 14.6% and an annual growth rate of 26.84 km2·year−1; (2) The rate of air temperature increase was different in the different seasons. The rate in the cold season was about 0.41 °C per ten years and 0.32 °C in hot season. Precipitation evidently increased, with a change rate of 17.70 mm per ten years in the hot season and a slight increase with a change rate of 2.36 mm per ten years in the cold season. Pan evaporation exhibited evidently decreasing trends in both the hot and cold seasons, with rates of −33.35 and −14.84 mm per ten years, respectively; (3) An evident delayed response of lake area change to climate change is observed, with a delay time of approximately one to two years. PMID:26528996

  2. Schistosomiasis Breeding Environment Situation Analysis in Dongting Lake Area

    NASA Astrophysics Data System (ADS)

    Li, Chuanrong; Jia, Yuanyuan; Ma, Lingling; Liu, Zhaoyan; Qian, Yonggang

    2013-01-01

    Monitoring environmental characteristics, such as vegetation, soil moisture et al., of Oncomelania hupensis (O. hupensis)’ spatial/temporal distribution is of vital importance to the schistosomiasis prevention and control. In this study, the relationship between environmental factors derived from remotely sensed data and the density of O. hupensis was analyzed by a multiple linear regression model. Secondly, spatial analysis of the regression residual was investigated by the semi-variogram method. Thirdly, spatial analysis of the regression residual and the multiple linear regression model were both employed to estimate the spatial variation of O. hupensis density. Finally, the approach was used to monitor and predict the spatial and temporal variations of oncomelania of Dongting Lake region, China. And the areas of potential O. hupensis habitats were predicted and the influence of Three Gorges Dam (TGB)project on the density of O. hupensis was analyzed.

  3. Late Archean mafic volcanism in the Rainy Lake area, Minnesota

    SciTech Connect

    Day, W.C.

    1985-01-01

    The Late Archean greenstone-granite terrane of the Rainy Lake area of Minnesota contains a bimodal suite of mafic and felsic volcanic and coeval intrusive rocks. New geochemical data show that the mafic rocks occur in three distinct suites: (1) low-Ti olivine- and quartz-tholeiite, (2) high-Ti quartz-tholeiite and basaltic andesite, and (3) calc-alkaline lamprophyric monzodiorite and quartz diorite. The low-Ti tholeiites have only slightly evolved Mg-numbers from 53-63, Ni=125-300 ppm, and MORB-like REE. In contrast, the high-Ti tholeiites are more evolved, with Mg*=26-48, Ni=43-135 ppm, and higher total REE. Compared to the tholeiitic suites, the monzodiorite suite has more primitive Mg-numbers, with Mg*=70-78, Ni<410 ppm, and anomalously high LREE. The two tholeiitic suites cannot be genetically related by simple fractionation from a single parent magma; however, lower degrees of partial melting (<8 percent) of a mantle source (spinel periodotite) with REE=2-4 times chondrites could have produced the high-Ti tholeiites, and higher degrees of melting (20-30 percent) of a similar source could have generated the low-Ti tholeiites. In contrast, the monzodiorite suite must have been generated from either a LREE-rich or (and) a garnet-bearing source (garnet periodotite). The authors conclude that shallow melting (<40-50 km) within the Archean mantle in the Rainy Lake area produced the tholeiitic rocks, and that deep melting (>40-50 km) generated the lamprophyric monzodiorites.

  4. Climatic and lake temperature data for Wetland P1, Cottonwood Lake Area, Stutsman County, North Dakota, 1982-87

    USGS Publications Warehouse

    Parkhurst, Renee S.; Sturrock, A.M.; Rosenberry, D.O.; Winter, T.C.

    1995-01-01

    Research on the hydrology of Wetland P1 and the Cottonwood Lake Area includes the study of evaporation. Presented here in a graphical format are those data collected during the open-water seasons of 1982-87 that were needed for energy- budget and mass-transfer evaporation studies. The data include air temperatures, water surface and lake-bottom temperatures, windspeed, radiation, humidity, and precipitation. Data were collected at a raft station and two land stations.

  5. Vegetation coverage change and associated driving forces in mountain areas of Northwestern Yunnan, China using RS and GIS.

    PubMed

    Peng, Jian; Liu, Yinghui; Shen, Hong; Han, Yinan; Pan, Yajing

    2012-08-01

    The dynamics of vegetation coverage and associated driving forces are one of the key issues in global environmental change. In the study, taking Lijiang County as a case, the Normalized Difference Vegetation Index was used to quantify vegetation coverage change in mountain areas of Northwestern Yunnan, China, with the application of remote sensing data and GIS technologies. And associated driving forces of vegetation coverage change were also analyzed, with a focus on land use change and elevation. The results showed that there was high vegetation coverage with a significant increase in the whole county during 1986-2002. However, due to economic development and the implementation of environmental protection polices, vegetation coverage change in the county showed distinct spatial diversity, which mainly behaved as the increasing in the northwest of the county with low human activities, and the decreasing in the south with high economic development. The results also showed that as a restrictive factor, elevation was of great signification on the spatial distribution of vegetation coverage in a broad scale; while in the county level, it was land use that determined the vegetation coverage, since the change of vegetation coverage grades in the study area was mainly associated with the change of land use types. PMID:21912871

  6. Hydrologic data for the drainage basins of Chatfield and Cherry Creek Lakes, Denver metropolitan area, Colorado

    USGS Publications Warehouse

    Gibbs, J.W.; Arnold, L.M.; Reed, R.L.

    1983-01-01

    Chatfield and Cherry Creek Lakes are flood control lakes constructed by the U.S. Army Corps of Engineers and leased to the Colorado Division of Parks and Recreation. Both lakes are in the Denver metropolitan area and provide a variety of recreational activities, including boating, camping, fishing, picnicking, and swimming. The projected increase of urban development in the drainage basins of Chatfield and Cherry Creek lakes could increase the constituent loads delivered to the lakes. Due to the eutrophic condition of Cherry Creek Lake and the potential eutrophic condition of Chatfield Lake, increased constituent loads could affect the suitability of the lakes for recreation. A monitoring program was started to determine the constituent loads of the drainage basins to both lakes. A network of monitoring stations was established to collect ambient water quality samples, storm runoff water quality samples, precipitation, and stream discharge. In the Cherry Creek basin 12 observation wells were established in the alluvium upgradient from Cherry Creek lake. Water levels and water quality data were collected to determine the quantity and quality of groundwater entering Cherry Creek lake. Data were collected from January through December 1982. The data may be used to evaluate the present and projected impact of urbanization in the drainage basins and the effect of increased constituent loads delivered to Chatfield and Cherry Creek lakes. (Author 's abstract)

  7. The Role of Trans Tensional Structures and Lake Mead Reservoir in Groundwater Flow in Black Canyon, Lake Mead National Recreation Area, NV-AZ

    NASA Astrophysics Data System (ADS)

    Justet, L.; Beard, S.

    2010-12-01

    Hot springs and seeps discharging into Black Canyon (BC) along the Colorado River in north Colorado River Valley (CRV) support endemic riparian ecosystems in the Lake Mead National Recreation Area. Increases in groundwater development in southern NV and northwestern AZ may impact spring discharge. Sources of spring discharge in BC were evaluated using geochemical methods. Kinematic analysis and geologic mapping of structures associated with BC springs were used to evaluate structural controls on groundwater flow in BC. Geochemical analysis indicates groundwater discharge near Hoover Dam (HD) and along the faulted edge of the Boulder City Pluton is derived from Lake Mead, high δ87Sr Proterozoic or Tertiary crystalline rock and, possibly, Tertiary sedimentary rock. Reducing conditions indicated by 234U/238U and δ34S concentrations suggest the groundwater is confined and/or derived from greater depths while carbon isotopes indicate the groundwater is old. Lighter δD and δO-18, modern tritium concentrations, post-Dam U disequilibrium ages, and occurrence of anthropogenic perchlorate support the presence of a young Lake Mead component. South of the pluton, the Lake Mead component is absent. More oxidizing conditions in this part of BC, indicated by the U and S isotope concentrations, suggest the groundwater is less confined and/or derived from shallower depths compared to groundwater discharging near HD. Older apparent groundwater ages and heavier δD and δO-18 values south of the pluton indicate slower flow paths from a lower elevation or latitude source. Clarifying the nature of groundwater flow in eastern NV, the analyses indicate that hydraulic connection between the regional carbonate aquifer and BC is unlikely. Instead, the data indicate sources of BC springs are derived relatively locally in CRV and, possibly, south Lake Mead Valley. Results of the geologic and kinematic analyses indicate faults that formed from the interaction of E-W extension related to

  8. 75 FR 35829 - Bear Lake National Wildlife Refuge, Oxford Slough Waterfowl Production Area, ID

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-23

    ... Fish and Wildlife Service Bear Lake National Wildlife Refuge, Oxford Slough Waterfowl Production Area... Production Area (WPA) in Oxford, Idaho. We are providing this notice in compliance with our CCP policy to... hydrology and ecological processes of the Bear Lake Watershed. Oxford Slough Waterfowl Production...

  9. 75 FR 6218 - New Melones Lake Area Resource Management Plan, Tuolumne and Calaveras Counties, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-08

    ... published in the Federal Register on November 2, 2009 (74 FR 56656). The written comment period on the Draft... Bureau of Reclamation New Melones Lake Area Resource Management Plan, Tuolumne and Calaveras Counties, CA... a Final RMP/EIS for the New Melones Lake Area. The Final RMP/EIS describes and presents...

  10. Characterization and comparison of phytoplankton in selected lakes of five Great Lakes area national parks

    USGS Publications Warehouse

    Nevers, Meredith Becker; Whitman, Richard L.

    2004-01-01

    Phytoplankton species have been widely used as indicators of lake conditions, and they may be useful for detecting changes in overall lake condition. In an attempt to inventory and monitor its natural resources, the National Park Service wants to establish a monitoring program for aquatic resources in the Great Lakes Cluster National Parks. This study sought to establish baseline information on the phytoplankton and water chemistry of selected lakes in five national parks in a preliminary effort toward establishing a long-term monitoring program. Phytoplankton and water chemistry samples were collected from ten lakes in five national parks over a two-year period. A total of 176 taxa were identified during the study. Northern lakes generally had higher Shannon-Wiener diversity and clustered together in similarity. Lakes exhibited a south to north gradient of many water chemistry variables, with northern lakes having lower hardness, sulfate, turbidity, and temperature and higher dissolved oxygen. Chloride and sulfate concentrations were the variables that best explained variation among phytoplankton in the ten lakes. A monitoring plan will have to incorporate the differences among lakes, but by coordinating the effort, comparisons within and among parks and other regions will prove useful for determining environmental change.

  11. Heterogeneity in High Latitude Lake Area Trends and Relationship to Landscape Characteristics

    NASA Astrophysics Data System (ADS)

    Roach, J.; Griffith, B.; Verbyla, D.

    2012-12-01

    During the past ~60 years, net declines in lake area have been identified in several circumpolar regions. Lakes and wetlands in Alaskan National Wildlife Refuges (NWRs) provide critical breeding habitats for migratory waterfowl and shorebirds. The loss of these breeding habitats may have far-reaching effects along migratory routes that extend to more southerly parts of North America, South America, Asia, and Australia. However, the magnitude, mechanisms, and biological implications of lake area change have not been fully evaluated across Alaskan refuge lands. The objectives of this work were to: 1) use historical aerial photography and remotely sensed imagery to estimate lake area trends for 8 Alaskan NWRs at two spatial scales; broad-scale estimates were obtained for 10 study areas, and fine-scale estimates were obtained for ~24,000 lakes in these study areas, 2) characterize local to regional heterogeneity in lake area trends, 3) relate heterogeneous lake area trends to landscape characteristics and associated mechanistic processes, and 4) build empirical models to understand the potential effects of changing lake area on waterfowl species richness. Net statewide trends were decreasing (-0.73% per year). However, there was heterogeneity in rates of change among individual lakes (26.2% to -34.1% per year) and among study areas (0.3 to -3.0% per year) since ~1985. The lack of a latitudinal (Arctic to sub-Arctic) or longitudinal (continental to maritime) pattern in study area trends suggested the involvement of substrate characteristics and landscape position, rather than regional climatic gradients, as mechanisms underlying heterogeneous lake area trends. Study areas with a greater proportion of lakes outside of the immediate floodplain zone (> ~1.8 km from rivers), but still in lowland areas with coarse-grained soils were most likely to have net declining trends in lake area. These results indicated drainage and negative hydraulic gradients between surface and

  12. DNA barcoding the Lepidoptera inventory of a large complex tropical conserved wildland, Area de Conservacion Guanacaste, northwestern Costa Rica.

    PubMed

    Janzen, Daniel H; Hallwachs, Winnie

    2016-09-01

    The 37-year ongoing inventory of the estimated 15 000 species of Lepidoptera living in the 125 000 terrestrial hectares of Area de Conservacion Guanacaste, northwestern Costa Rica, has DNA barcode documented 11 000+ species, and the simultaneous inventory of at least 6000+ species of wild-caught caterpillars, plus 2700+ species of parasitoids. The inventory began with Victorian methodologies and species-level perceptions, but it was transformed in 2004 by the full application of DNA barcoding for specimen identification and species discovery. This tropical inventory of an extraordinarily species-rich and complex multidimensional trophic web has relied upon the sequencing services provided by the Canadian Centre for DNA Barcoding, and the informatics support from BOLD, the Barcode of Life Data Systems, major tools developed by the Centre for Biodiversity Genomics at the Biodiversity Institute of Ontario, and available to all through couriers and the internet. As biodiversity information flows from these many thousands of undescribed and often look-alike species through their transformations to usable product, we see that DNA barcoding, firmly married to our centuries-old morphology-, ecology-, microgeography-, and behavior-based ways of taxonomizing the wild world, has made possible what was impossible before 2004. We can now work with all the species that we find, as recognizable species-level units of biology. In this essay, we touch on some of the details of the mechanics of actually using DNA barcoding in an inventory. PMID:27584861

  13. Fault activity in the epicentral area of the 1580 Dover Strait (Pas-de-Calais) earthquake (northwestern Europe)

    NASA Astrophysics Data System (ADS)

    García-Moreno, D.; Verbeeck, K.; Camelbeeck, T.; De Batist, M.; Oggioni, F.; Zurita Hurtado, O.; Versteeg, W.; Jomard, H.; Collier, J. S.; Gupta, S.; Trentesaux, A.; Vanneste, K.

    2015-05-01

    On 1580 April 6 one of the most destructive earthquakes of northwestern Europe took place in the Dover Strait (Pas de Calais). The epicentre of this seismic event, the magnitude of which is estimated to have been about 6.0, has been located in the offshore continuation of the North Artois shear zone, a major Variscan tectonic structure that traverses the Dover Strait. The location of this and two other moderate magnitude historical earthquakes in the Dover Strait suggests that the North Artois shear zone or some of its fault segments may be presently active. In order to investigate the possible fault activity in the epicentral area of the AD 1580 earthquake, we have gathered a large set of bathymetric and seismic-reflection data covering the almost-entire width of the Dover Strait. These data have revealed a broad structural zone comprising several subparallel WNW-ESE trending faults and folds, some of them significantly offsetting the Cretaceous bedrock. The geophysical investigation has also shown some indication of possible Quaternary fault activity. However, this activity only appears to have affected the lowermost layers of the sediment infilling Middle Pleistocene palaeobasins. This indicates that, if these faults have been active since Middle Pleistocene, their slip rates must have been very low. Hence, the AD 1580 earthquake appears to be a very infrequent event in the Dover Strait, representing a good example of the moderate magnitude earthquakes that sometimes occur in plate interiors on faults with unknown historical seismicity.

  14. Derivation of Lake Areas and Elevations for the Mackenzie Basin Using Satellite Remote Sensing

    NASA Technical Reports Server (NTRS)

    Birkett, Charon; Kite, Geoff

    1997-01-01

    Modelling hydrological processes in large watersheds flowing to the Arctic ocean is one step towards larger-scale modelling of the global water and energy cycles. Models of the Mackenzie River Basin (Northern Canada) are currently available but omit explicit routing of river flows through the three main lakes - Athabasca, Great Slave Lake and Great Bear Lake (Kite et al, 1994). These lakes occupy an area of 65,000 sq km but little gauge information is available. The levels of the lakes are only measured at a few points on the circumferences and river flows are only measured downstream. The hydraulic relationships between level/discharge and level/area/volume are uncertain. It has been previously shown that satellite remote sensing can be utilised in providing measurements of both lake surface area using imaging techniques and lake level using radar altimetry (Birkett, 1994). Here, we explore the application of these techniques to derive the lake levels and areas for the Mackenzie Basin lakes.

  15. Regional hydrology of the Green River-Moab area, northwestern Paradox basin, Utah

    USGS Publications Warehouse

    Rush, F.E.; Whitfield, M.S.; Hart, I.M.

    1984-01-01

    The Green River-Moab area encompasses about 7,800 square kilometers or about 25 percent of the Paradox basin. The entire Paradox basin is a part of the Colorado Plateaus that is underlain by a thick sequence of evaporite (salt) beds of Pennsylvanian age. The rock units that underlie the area have been grouped into hydrogeologic units based on their water-transmitting ability. Confining beds consist of evaporite beds of mostly salt, and overlying and underlying thick sequences of rocks with minimal permeability; above and below these confining beds are aquifers. The upper Mesozoic sandstone aquifer, probably is the most permeable hydrogeologic unit of the area and is the subject of this investigation. The principal component of groundwater outflow from this aquifer probably is subsurface flow to regional streams (the Green and Colorado Rivers) and is about 100 million cubic meters per year. All other components of outflow are relatively small. The average annual recharge to the aquifer is about 130 million cubic meters, of which about 20 million cubic meters is from local precipitation. For the lower aquifer, all recharge and discharge probably is by subsurface flow and was not estimated. The aquifers are generally isolated from the evaporite beds by the hounding confining beds; as a result, most ground water has little if any contact with the evaporites. Brines are present in the confining beds, but solution of beds of salt probably is very slow in most parts of the area. No brine discharges' have been identified.

  16. Two new species of Erythromelana Townsend, 1919 (Diptera: Tachinidae) from Area de Conservación Guanacaste in northwestern Costa Rica

    PubMed Central

    Wood, D. Monty; Smith, M. Alex; Hallwachs, Winnie; Janzen, Daniel; Dapkey, Tanya

    2016-01-01

    Abstract Background We describe two new species in the genus Erythromelana Townsend, 1919 from Area de Conservación Guanacaste (ACG) in northwestern Costa Rica. Both species were reared from wild-caughtcaterpillars of Eois spp. (Lepidoptera: Geometridae). We provide a concise description of each species using morphology, life history, molecular data, and photographic documentation. New information Erythromelana jimmychevezi Fleming & Wood sp. nov. Erythromelana glenriverai Fleming & Wood sp. nov. PMID:27226745

  17. Dynamic monitoring of Poyang Lake water body area using MODIS images between 2000 and 2014

    NASA Astrophysics Data System (ADS)

    Sun, Yayong; Huang, Shifeng; Li, Jiren; Li, Xiaotao; Ma, Jianwei; Li, Shanyang; Wang, Hui

    2015-12-01

    Poyang Lake, the largest freshwater lake of China, is well known for its ecological and economic importance as a dynamic wetland system. But, influenced by the climate change and human activity, Poyang Lake wetland has changed a lot. The long time series of Terra/MODIS data between 2000 and 2014 were utilized to investigate the variation of Poyang Lake and to analyze Poyang lake response to variation of local precipitation with the meteorological data. The results showed: (1) Poyang Lake water body area showed a significant seasonal variation, minimum value was about 690 km2 and maximum value reached 3500 km2, and inter-annual fluctuation; (2)For the past 15 year , local precipitation directly affected the inundation changes. In particular, the impact of rainfall during the first half of the year is more significant (the relation coefficient with R2 of 0.61); (3) Taking into account humid activities, the impoundment of the Three Gorges dam (TGD) had a certain impact on Poyang Lake water body area, especially the persistent reduction of Poyang lake surface area in November was deteriorated by the impounding of TGD in October after 2006. Finally, the study provides a theoretical basis and data for changes in Poyang Lake wetland research and protection.

  18. Changes in lake area in response to thermokarst processes and climate in Old Crow Flats, Yukon

    NASA Astrophysics Data System (ADS)

    Lantz, T. C.; Turner, K. W.

    2015-03-01

    Growing evidence indicates that lake-dominated ecosystems at high latitudes are undergoing significant hydrological changes. Research examining these changes is complicated because both thermokarst and climatic processes likely influence lake dynamics. To examine the relative impacts of these processes in permafrost landscapes, we investigated the dynamics of lake area and number in Old Crow Flats (OCF), Yukon using historical air photos and satellite imagery. Between 1951 and 2007, OCF experienced a decline of ~6000 ha in total lake area but gained 232 lakes. Close to half (49%) of the difference in lake area was driven by the rapid and persistent drainage of 38 large lakes. These catastrophic drainages were associated with new or enlarged outlet channels, resulted in the formation of numerous residual ponds, and were likely driven by thermokarst processes. Our analysis shows that catastrophic lake drainages have become more than 5 times more frequent in recent decades. These changes are likely related to the impacts of increased temperature and precipitation on thermokarst processes. Fifty-nine of the 170 intensively studied lakes showed either large bidirectional fluctuations or gradual cumulative declines. These changes affected a much smaller portion of OCF and were likely driven by interactions between increased precipitation and temperature and individual catchment characteristics. To anticipate landscape-scale changes in these systems, and assess their impact on hydrology, wildlife habitat, and carbon storage, field research is required to better characterize the mechanisms responsible for changes.

  19. The late holocene palaeoenvironment in the Lake Njupi area, west Cameroon: implications regarding the history of Lake Nyos

    NASA Astrophysics Data System (ADS)

    Zogning, Appolinaire; Giresse, Pierre; Maley, Jean; Gadel, François

    1997-04-01

    Lake Njupi, 1 km east of Lake Nyos, on the Cameroon Volcanic Line, was formed by the damming of a local crustal depression. Two cores from Lake Nyos were analysed which penetrated sediments at the margin of the lake. The older deposits give an age of 3400 years BP and this date is proposed as a minimum age for Lake Njupi. Sedimentological, palynological and geochemical studies of a 2 m section provide an opportunity to reconstruct the Late Holocene environmental history. It is an organic-rich deposit (organic carbon up to 30%) with an abundant Silicospongia spicules fraction. An obvious sedimentary homogeneity is interrupted by 5 fine to coarse layers with sandy quartz and lignitic remains. Such inputs were denoted by carbohydrate maxima or sometimes by phenolic compounds. This study confirms the evidence of an arid period culminating between 2500 and 2000 yrs BP. This crisis began around 3000 yrs BP in the rain forest area of West Cameroon and also further to the south in Congo. Lake Njupi, situated today in a mostly grassland savanna environment known as the "Grass Fields", provides evidence for environmental changes from a mosaic of forest and savanna before 2500 years BP to a savanna characterised by high grass pollen contents (75 to 85%), with small islands of forest. The mountain vegetation characterised by Podocarpus and Olea capensis retreated around 2300 years BP at the time Elaeis guineensis (the Oil Palm) began its extension as a pioneer tree, later providing opportunities for its domestication by man.

  20. Density-independent survival of wild lake trout in the Apostle Islands area of Lake Superior

    USGS Publications Warehouse

    Bronte, Charles R.; Schram, Stephen T.; Selgeby, James H.; Swanson, Bruce L.

    1995-01-01

    The lake trout (Salvelinus namaycush) stock at Gull Island Shoal in western Lake Superior was one of only a few stocks of lean lake trout in the Great Lakes that survived overfishing and predation by the sea lamprey (Petromyzon marinus). Since the mid 1960s, the abundance of wild recruits measured at age 0 and the number of age-7 to -11 wild fish recruited to the fishable stock have increased. We used the Varley-Gradwell method to test for density-dependent survival between these life stages. Survival from age-0 to ages 7–11 was not affected by increasing density, which suggests that further increases in recruitment and stock size are still possible. We suggest that testing for the existence of density-dependent survival can be used to indicate when lake trout populations are rehabilitated.

  1. The Cinder Lake Intrusive Complex, Knee Lake area, Central Manitoba: a Syenite- Carbonatite Association from a Neoarchean Continental Margin

    NASA Astrophysics Data System (ADS)

    Chakhmouradian, A. R.; Böhm, C. O.; Kressall, R. D.; Lenton, P. G.

    2009-05-01

    The Cinder Lake intrusive complex is the only known occurrence of feldspathoid rocks in Manitoba. These rocks were initially mapped in the southeastern part of the Lake by Elbers (in Gilbert, 1985) and Lenton (1985), but have not been adequately studied. On the basis of new field, petrographic and geochemical evidence acquired in 2008, three discrete intrusive phases can be presently identified at Cinder Lake: fine-grained aegirine-nepheline syenite, fine-grained biotite-vishnevite syenite and syenitic pegmatite. There is also convincing mineralogical and geochemical evidence for the presence of unexposed clinopyroxenite and carbonatitic units genetically associated with the alkaline syenitic rocks. The evidence for the presence of unexposed carbonatite includes pervasive calcitization of the syenitic rocks, occurrence of rare-earth minerals (britholite, monazite and REE-rich apatite) in association with Sr-rich calcite in metasomatised pegmatite, and andradite veins crosscutting the syenites. The geochemistry of the Cinder Lake rocks is most consistent with the HFSE-depleted, potassic, high-Ba/La and high-Th/Nb signature of arc magmas (Edwards et al., 1994). In common with island-arc and continental-margin phonolites, the Cinder Lake syenites are potassic rocks with a chondritic Zr/Hf ratio, strong enrichment in Ba relative to La and Th relative to Nb. Uranium-lead dating of zircon crystals recovered from the biotite-vishnevite syenite yielded an age of 2705±2 Ma, interpreted as the timing of syenite emplacement. This value is close to the age of the incipient accretion of subprovinces in the northwestern Superior province at 2.70-2.71 Ga (Davis et al. 2005). Given this age relationship, the Cinder Lake complex is probably derived from magmas produced in a Neoarchean subduction zone underlying the North Caribou microcontinent. The regional geological setting of the complex (abundance of tonalite and granodiorite among the plutonic rocks and the predominance of

  2. Parasitic and Bacterial Infections of Myocastor coypus in a Metropolitan Area of Northwestern Italy.

    PubMed

    Zanzani, Sergio A; Di Cerbo, Annarita; Gazzonis, Alessia L; Epis, Sara; Invernizzi, Anna; Tagliabue, Silvia; Manfredi, Maria T

    2016-01-01

    Coypus (Myocastor coypus) are widespread throughout Europe. In northern Italy, they are abundant in the flatland areas, and their high population densities can cause economic loss and ecosystem damage. We examined 153 coypus for selected parasitic and bacterial infections. We found Strongyloides myopotami (63.4% prevalence), Trichostrongylus duretteae (28.1%), Eimeria coypi (86.3%), and Eimeria seideli (6.8%), but did not find Giardia duodenalis or Cryptosporidium spp. We also isolated Staphylococcus aureus (10.1%), Escherichia coli (4.5%), and Streptococcus spp. (3.4%) from lung samples; no Salmonella spp. were isolated from fecal samples. Coypus had antibodies to Toxoplasma gondii (28.9%) and to four serovars of Leptospira interrogans (44.9%); Australis/Bratislava was the serovar most frequently detected. It is clear that coypu can be infected with pathogens of human and veterinary importance. PMID:26745834

  3. 3D Stress Modelling of a Neotectonically Active Area in Northwestern Norway

    NASA Astrophysics Data System (ADS)

    Gradmann, Sofie; Keiding, Marie; Olesen, Odleiv; Maystrenko, Yuriy

    2016-04-01

    The Nordland area in NW Norway is one of the tectonically most active areas in Fennoscandia. It exhibits patterns of extension, which are in contradiction to the first-order regional stress pattern which reflects compression from ridge-push. The regional stress field stems from the interaction of ridge push and GIA (glacial isostatic adjustment); the local stress field mainly results from gravitational stresses as well as the flexural effects of sediment erosion and re-deposition. Whereas the first three effects are fairly well constrained, the latter is only poorly known and is the focus of this study. A number of data sets are collected within the project: Seismicity is monitored by a 2-year local seismic network and the stress regime at depth is derived from fault plane solutions. Surface deformation is recorded by a dense GPS network and DInSAR satellites. In-situ stresses are measured in a couple of relevant boreholes. We develop 3D finite element numerical models of crustal scale, using existing geometric constraints from previous geophysical studies. Internal body forces (e.g. variations in topography) already yield significant deviatoric stresses, which are often omitted in stress models. We apply the far-field stress fields (GIA, ridge-push, sediment redistribution) as effective force boundary conditions to the sides or base of the model. This way, we can account for all stress sources at once, but can also vary them separately in order to examine their relative contributions to the observed stress and strain rate fields. We develop a best-fit model using the different seismological and geodetic data sets collected and compiled within the project. Effects of lateral density changes and pre-existing weakness zones on stress localization are studied in connection to observed clusters of enhanced seismic activity.

  4. Using SWAT to target critical source sediment and phosphorus areas in the Wister Lake Basin, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wister Lake is located in the San Bois Mountains in southeastern Oklahoma, USA. The reservoir is primarily used as a water supply and flood storage to over 40,000 residents in the area. Due to high levels of phosphorus and sediment, Wister Lake is listed as a high priority basin for the State of Okl...

  5. MONITORING APPROACHES FOR ASSESSING QUALITY OF HIGH ALTITUDE LAKES: COLORADO FLAT TOPS WILDERNESS AREA

    EPA Science Inventory

    Results of a joint U.S. Environmental Protection Agency and U.S. Geological Survey sampling effort conducted during 1982 and 1983 on three lakes in the Flat Tops Wilderness Area of Colorado are summarized. Ned Wilson, Oyster and Upper Island Lakes were surveyed. They are represen...

  6. Determination of critical source areas for phosphorous losses: Lake Champlain Basin, Vermont

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lake Champlain, located between Vermont, New York, and Quebec, exhibits eutrophication due to continuing phosphorus (P) inputs mainly from upstream nonpoint source areas. To address the Lake's eutrophication problem and as part of total maximum daily load (TMDL) requirements, a state-level P reducti...

  7. SWAT modeling of Critical Source Area for Runoff and Phosphorus losses: Lake Champlain Basin, VT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lake Champlain, located between Vermont, New York, and Quebec, exhibits eutrophication due to continuing phosphorus (P) inputs mainly from upstream nonpoint source areas. To address the Lake's eutrophication problem and as part of total maximum daily load (TMDL) requirements, a state-level P reducti...

  8. Substrate conditions and abundance of lake trout eggs in a traditional spawning area in southeastern Lake Michigan

    USGS Publications Warehouse

    Dorr, John A., III; O'Connor, Daniel V.; Foster, Neal R.; Jude, David J.

    1981-01-01

    Spawning by planted lake trout (Salvelinus namaycush) was documented by sampling with a diver-assisted pump in a traditional spawning area in southeastern Lake Michigan near Saugatuck, Michigan in mid-November in 1978 and 1979. Bottom depths at the 11 locations sampled ranged from 3 to 12 m and substrate size from boulders to sand. Periphyton (Cladophora and associated biota) was several millimeters thick at most stations but sparse at the shallowest. The most eggs recovered from a single sample occurred at the shallowest depth (3 m). In both years, some of the small numbers of eggs collected (9 in 1978, 14 in 1979) were alive and fertilized. Laboratory incubation of viable eggs resulted in successful hatching of larvae. When compared with egg densities measured at spawning sites used by self-sustaining populations of lake trout in other lakes, densities in the study are (0-13/m2) appeared to be critically low. Insufficient numbers of eggs, combined with harsh incubation conditions (turbulence, ice scour, sedimentation), were implicated as prime causes for lake trout reproductive failure in the study area, although other factors, such as inappropriate spawning behavior (selection of suboptimal spawning location, depth, or substrate) also may have reduced survival of eggs and larvae.

  9. Hydrologic relations between lakes and aquifer in a recharge area near Orlando, Florida

    USGS Publications Warehouse

    Lichtler, William F.; Hughes, G.H.; Pfischner, F.L.

    1976-01-01

    The three lakes investigated in Orange County, Florida, gain water from adjoining water-table aquifer and lose water to Floridan aquifer by downward leakage. Net seepage (net exchange of water between lake and aquifers) can be estimated by equation S = AX + BY, where S is net seepage, X represents hydraulic gradient between lake and water-table aquifer, A is lumped parameter representing effect of hydraulic conductivity and cross-sectional area of materials in flow section of water-table aquifer, Y is head difference between lake level and potentiometric surface of Floridan aquifer, and B is lumped parameter representing effect of hydraulic conductivity, area, and thickness of materials between lake bottom and Floridan aquifer. If values of S, X, and Y are available for two contrasting water-level conditions, coefficients A and B are determinable by solution of two simultaneous equations. If the relation between lake and ground-water level is the same on all sides of the lake--with regard to each aquifer--and if X and Y are truly representative of these relations, then X and Y terms of equation provide valid estimates of inflow to lake from water-table aquifer and outflow from lake to Floridan aquifer. (Woodard-USGS)

  10. Monitoring of the water-area variations of Lake Dongting in China with ENVISAT ASAR images

    NASA Astrophysics Data System (ADS)

    Ding, XianWen; Li, XiaoFeng

    2011-12-01

    As an active microwave remote sensing sensor, synthetic aperture radar (SAR) can image the Earth surface with high spatial resolution in both day and night under all weather conditions. In this paper, a digital image processing technique was implemented to extract water area information from SAR images and the result is used to monitor the water area variation of Lake Dongting, the second largest freshwater lake in China. 8-year time series of European Space Agency's ENVISAT ASAR (Advanced Synthetic Aperture Radar) images acquired between 2002 and 2009 were obtained and a land-water classification scheme was implemented. Using independent in situ water level data measured at a lake-side hydrologic station during study period, we derived the relationship between water level and water area of Lake Dongting. The results show that, (1) during dry seasons, the water area is 518 km 2 larger than that in the 1990s reported by Yangtze BHYRWRC (Bureau of Hydrology and Yangtze River Water Resources Commission), 2000; (2) the water area of Lake Dongting increased significantly in the 2000s after the Chinese Government's "return land to lake" policy took effect in 1998; (3) the water level of Lake Dongting could be low during a rainy season due to drought; but could be high in a dry season due to discharges from the upstream Three Gorges Dam. In addition, the relationship between water storage change and water area/level change is obtained.

  11. Oxygen isotope mapping of the Archean Sturgeon Lake caldera complex and VMS-related hydrothermal system, Northwestern Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Holk, Gregory J.; Taylor, Bruce E.; Galley, Alan G.

    2008-08-01

    The hydrothermal and magmatic evolution of the Sturgeon Lake caldera complex is graphically documented by a regional-scale (525 km2) analysis of oxygen isotopes. Spatial variations in whole-rock oxygen isotope compositions provide a thermal map of the cumulative effects of multiple stages of hydrothermal metasomatism before, during, and after volcanogenic massive sulfide (VMS) mineralization. There is a progressive, upward increase in δ18O from less than 2‰ to greater than 15‰ through a 5-km-thick section above the Biedelman Bay subvolcanic intrusive complex. This isotopic trend makes it clear that at least the earlier phases of this intrusive complex were coeval with the overlying VMS-hosting cauldron succession and provided thermal energy to drive a convective hydrothermal circulation system. The sharp contrast in δ18O values between late stage phases of the Biedelman Bay intrusion and immediate hanging wall strata indicates that the main phase of VMS-related hydrothermal activity took place before late-stage resurgence in the cauldron-related magmatic activity. Mineralogical and isotopic evidence indicates the presence of both syn- and postmineralization hydrothermal activity defined by the presence of widespread semiconformable and more restricted discordant alteration zones that affect the pre- and syncauldron strata. The semiconformable alteration zones formed during early stages of hydrothermal circulation and are defined by widespread silicification and carbonatization in association with relatively high δ18O values. The discordant alteration assemblages, containing Al-silicate minerals with chloritoid and/or Fe-rich carbonate or chlorite, centered on synvolcanic faults represent restricted zones of both seawater inflow and hydrothermal fluid upflow. A rapid increase in δ18O values (˜7-9‰) over a short distance (<200 m) suggests marked cooling of hydrothermal fluid from ˜350°C to less than 130°C either just before or during discharge onto the

  12. Impact of lake breezes on ozone and nitrogen oxides in the Greater Toronto Area

    NASA Astrophysics Data System (ADS)

    Wentworth, G. R.; Murphy, J. G.; Sills, D. M. L.

    2015-05-01

    Meteorological and air quality datasets from summertime (May to September, 2010-2012) were analysed in order to assess the influence of lake-breeze circulations on pollutant levels in the Greater Toronto Area (GTA). While previous estimates of the frequency of summer days experiencing lake breezes range between 25 and 32 % for the GTA, a simple algorithm using surface meteorological observations suggested Lake Ontario breezes occurred on 56% of summer days, whereas a more reliable multiplatform approach yielded a frequency of 74%. Data from five air quality stations across the GTA were used to compare air quality on days during which a lake-breeze circulation formed ("lake breeze days") versus days when one did not ("non-lake breeze days"). Average daytime O3 maxima were 13.6-14.8 ppb higher on lake breeze days relative to non-lake breeze days. Furthermore, the Ontario Ambient Air Quality Criteria (AAQC) for 1-h average O3 (80 ppb) and 8-h average O3 (65 ppb) were exceeded only on lake breeze days and occurred on a total of 30 and 54 days throughout the study period, respectively. A causal link between lake-breeze circulations and enhanced O3 was identified by examining several days in which only some of the air quality sites were inside the lake-breeze circulation. O3 mixing ratios at sites located within the circulation were at least 30 ppb higher than sites outside the circulation, despite similar temperatures, cloud conditions and synoptic regimes across the region. Rapid O3 increases were concurrent with the arrival of the lake-breeze front, suggesting O3-rich air from over the lake is being advected inland throughout the day. Lake-breeze circulations were found to have less impact on nitrogen oxide (NOx) levels. Morning NOx was greater on lake breeze days, probably due to the stagnant conditions favourable for lake breeze formation. During the late afternoon, only inland sites experience increased NOx on lake breeze days, likely as a result of being downwind

  13. Availability and quality of water from drift aquifers in Marshall, Pennington, Polk, and Red Lake counties, northwestern Minnesota

    USGS Publications Warehouse

    Lindgren, R.J.

    1996-01-01

    The concentration and percentage (as percent of total cations) of sodium, and concentration of dissolved solids tend to increase from east to west along regional flow paths. Concentrations and percentages (as percent of total anions) of chloride tend to be greater in the western part of the study area than in the eastern part. These trends are probably due to longer residence time of the water in the flow system, and upward leaka

  14. Temporal and Spatial Patterns in Thermokarst Lake Area Change in Yukon Flats, Alaska: an Indication of Permafrost Degradation

    NASA Astrophysics Data System (ADS)

    Chen, M.; Rowland, J. C.; Wilson, C. J.; Altmann, G.; Brumby, S. P.

    2011-12-01

    The formation, expansion, and drainage of thermokarst lakes is determined by the lateral and vertical degradation of permafrost. Consequently, areal changes in thermokarst lakes can reflect changes in the spatial distribution and depth of permafrost. However, natural variability in lake areas confounds the long term trend and makes it difficult to detect permafrost degradation by simply comparing lake areas from different time periods. In this study, we used Landsat images of 16 time periods between 1984 and 2009 to extract lake area (closed basin lakes only) for a 422,382 ha study area within Yukon Flats, Alaska. A multiple linear regression model was built to quantify the long term change in lake area. In this model, we included LWB (local water balance, defined as difference between total precipitation and total potential evapotranspiration since the preceding October), MDT (mean daily temperature from May 1st to the date that Landsat image was acquired) and PRD (four time periods: 1984-1986, 1992, 1999-2002, and 2009). MDT was used to indicate the active layer depth. Both LWB and MDT were used to account for natural variability in lake area. The model explained 95% of the total variability in lake area, with 62%, 16% and 17% accounted for by LWB, MDT and PRD respectively. Using the total lake area (15898 ha) in 1984-1986 as a baseline, lake area increased by 12% in 1992, and decreased by 6% during 1999-2002 and 8% in 2009. Among the 1,667 lakes, 267 lakes showed an area decrease and 115 lakes showed an increase. The expanding lakes were distributed along the Yukon River and its main tributaries (Beaver creek and Birch creek), while the shrinking lakes were located farther away from rivers or on fluvial terraces. A potential reason for the spatial pattern of expanding and shrinking lakes is that, after permafrost thaws, lakes can become connected to the groundwater system. Lakes close to the rivers may be recharged by groundwater due to their lower position

  15. 36 CFR 7.55 - Lake Roosevelt National Recreation Area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... persons in the water. (iii) The stretch of the Spokane Arm from 200 feet west of the Two Rivers Marina on the downstream end, to 200 feet east of the Fort Spokane launch ramp on the upstream end, above the... the “narrows” to the confluence of the lake, marked by “flat wake” buoy(s). (ii) Within 200 feet...

  16. Flooding in northwestern Hillsborough and southern Pasco counties, Florida, in 1979

    USGS Publications Warehouse

    Murphy, W.R., Jr.; Evans, R.P.; Whalen, James K.

    1984-01-01

    Heavy rainfall in the late spring and summer of 1979 caused severe flooding in northwestern Hillsborough and southern Pasco counties, including north Tampa. May 7-9 rainfall for some stations had a recurrence interval in excess of 100 years; the August and September rainfall total had a recurrence interval in excess of 50 years. The frequency of flooding of streams and lakes in the study area for the May 7-9 storm ranged from less than 2 to 25 years; for the period August to October, recurrence intervals ranged from 3 to 25 years. Areas of maximum flooding for a 48-square-mile area of northwestern Hillsborough and southern Pasco Counties are indicated on 12 sheets of aerial photography. Drainage patterns, control structures, drainage basins, and existing and proposed urban developments are shown and related to flooding. Stage and streamflow hydrographs are shown for 12 lakes and 2 streams. (USGS)

  17. Pronounced chemical response of Subarctic lakes to climate-driven losses in surface area.

    PubMed

    Lewis, Tyler L; Lindberg, Mark S; Schmutz, Joel A; Heglund, Patricia J; Rover, Jennifer; Koch, Joshua C; Bertram, Mark R

    2015-03-01

    Losses in lake area have been observed for several Arctic and Subarctic regions in recent decades, with unknown consequences for lake ecosystems. These reductions are primarily attributed to two climate-sensitive mechanisms, both of which may also cause changes in water chemistry: (i) increased imbalance of evaporation relative to inflow, whereby increased evaporation and decreased inflow act to concentrate solutes into smaller volumes; and (ii) accelerated permafrost degradation, which enhances sublacustrine drainage while simultaneously leaching previously frozen solutes into lakes. We documented changes in nutrients [total nitrogen (TN), total phosphorus (TP)] and ions (calcium, chloride, magnesium, sodium) over a 25 year interval in shrinking, stable, and expanding Subarctic lakes of the Yukon Flats, Alaska. Concentrations of all six solutes increased in shrinking lakes from 1985-1989 to 2010-2012, while simultaneously undergoing little change in stable or expanding lakes. This created a present-day pattern, much weaker or absent in the 1980s, in which shrinking lakes had higher solute concentrations than their stable or expanding counterparts. An imbalanced evaporation-to-inflow ratio (E/I) was the most likely mechanism behind such changes; all four ions, which behave semiconservatively and are prone to evapoconcentration, increased in shrinking lakes and, along with TN and TP, were positively related to isotopically derived E/I estimates. Moreover, the most conservative ion, chloride, increased >500% in shrinking lakes. Conversely, only TP concentration was related to probability of permafrost presence, being highest at intermediate probabilities. Overall, the substantial increases of nutrients (TN >200%, TP >100%) and ions (>100%) may shift shrinking lakes towards overly eutrophic or saline states, with potentially severe consequences for ecosystems of northern lakes. PMID:25294238

  18. Pronounced chemical response of Subarctic lakes to climate-driven losses in surface area

    USGS Publications Warehouse

    Lewis, Tyler L.; Lindberg, Mark S.; Schmutz, Joel A.; Heglund, Patricia J.; Rover, Jennifer R.; Koch, Joshua C.; Bertram, Mark R.

    2014-01-01

    Losses in lake area have been observed for several Arctic and Subarctic regions in recent decades, with unknown consequences for lake ecosystems. These reductions are primarily attributed to two climate-sensitive mechanisms, both of which may also cause changes in water chemistry: (i) increased imbalance of evaporation relative to inflow, whereby increased evaporation and decreased inflow act to concentrate solutes into smaller volumes; and (ii) accelerated permafrost degradation, which enhances sublacustrine drainage while simultaneously leaching previously frozen solutes into lakes. We documented changes in nutrients [total nitrogen (TN), total phosphorus (TP)] and ions (calcium, chloride, magnesium, sodium) over a 25 year interval in shrinking, stable, and expanding Subarctic lakes of the Yukon Flats, Alaska. Concentrations of all six solutes increased in shrinking lakes from 1985–1989 to 2010–2012, while simultaneously undergoing little change in stable or expanding lakes. This created a present-day pattern, much weaker or absent in the 1980s, in which shrinking lakes had higher solute concentrations than their stable or expanding counterparts. An imbalanced evaporation-to-inflow ratio (E/I) was the most likely mechanism behind such changes; all four ions, which behave semiconservatively and are prone to evapoconcentration, increased in shrinking lakes and, along with TN and TP, were positively related to isotopically derived E/I estimates. Moreover, the most conservative ion, chloride, increased >500% in shrinking lakes. Conversely, only TP concentration was related to probability of permafrost presence, being highest at intermediate probabilities. Overall, the substantial increases of nutrients (TN >200%, TP >100%) and ions (>100%) may shift shrinking lakes towards overly eutrophic or saline states, with potentially severe consequences for ecosystems of northern lakes.

  19. Ground-water quality and vulnerability to contamination in selected agricultural areas of southeastern Michigan, northwestern Ohio, and northeastern Indiana

    USGS Publications Warehouse

    Thomas, Mary Ann

    2000-01-01

    Ground-water quality was assessed in the northeastern part of the Corn Belt, where tile-drained row crops are underlain by fractured glacial till. Data were collected from 30 shallow monitor wells and 18 co-located domestic wells as part of the U.S. Geological Survey?s National Water-Quality Assessment in the Lake Erie-Lake St. Clair Basin. Pesticides or pesticide degradates were detected in 41 percent of the monitor wells and 6 percent of the domestic wells. The pesticides detected closely correspond to those most heavily applied?herbicides used on corn and soybeans. Pesticide degradates were detected three times more frequently, and at higher concentrations, than were parent compounds. No pesticide concentration exceeded a USEPA Maximum Contaminant Level (MCL), but MCL?s have not been established for 9 of the 11 compounds detected. Thirty-seven percent of monitor-well samples had nitrate concentrations indicative of human influences such as fertilizer, manure or septic systems. Nitrate was the only chemical constituent detected at a concentration greater than an MCL. The MCL was exceeded in 7 percent of samples from monitor wells which were too shallow to be used as a source of drinking water. Pesticide and nitrate concentrations in the study area are low relative to other agricultural areas of the Nation. Several authors have suggested that ground water in parts of the Upper Mid-west is minimally contaminated because it is protected by the surficial glacial till or tile drains. These ideas are examined in light of the relations between concentration, well depth, and ground-water age in the study area. Most of the shallow ground water is hydraulically connected to the land surface, based on the observations that 83 percent of waters from monitor wells were recharged after 1953, and 57 percent contained a pesticide or an elevated nitrate concentration. Fractures or sand-and-gravel stringers within the till are the probable pathways. In some areas, deeper parts of

  20. Geologic map database of the El Mirage Lake area, San Bernardino and Los Angeles Counties, California

    USGS Publications Warehouse

    Miller, David M.; Bedford, David R.

    2000-01-01

    This geologic map database for the El Mirage Lake area describes geologic materials for the dry lake, parts of the adjacent Shadow Mountains and Adobe Mountain, and much of the piedmont extending south from the lake upward toward the San Gabriel Mountains. This area lies within the western Mojave Desert of San Bernardino and Los Angeles Counties, southeastern California. The area is traversed by a few paved highways that service the community of El Mirage, and by numerous dirt roads that lead to outlying properties. An off-highway vehicle area established by the Bureau of Land Management encompasses the dry lake and much of the land north and east of the lake. The physiography of the area consists of the dry lake, flanking mud and sand flats and alluvial piedmonts, and a few sharp craggy mountains. This digital geologic map database, intended for use at 1:24,000-scale, describes and portrays the rock units and surficial deposits of the El Mirage Lake area. The map database was prepared to aid in a water-resource assessment of the area by providing surface geologic information with which deepergroundwater-bearing units may be understood. The area mapped covers the Shadow Mountains SE and parts of the Shadow Mountains, Adobe Mountain, and El Mirage 7.5-minute quadrangles. The map includes detailed geology of surface and bedrock deposits, which represent a significant update from previous bedrock geologic maps by Dibblee (1960) and Troxel and Gunderson (1970), and the surficial geologic map of Ponti and Burke (1980); it incorporates a fringe of the detailed bedrock mapping in the Shadow Mountains by Martin (1992). The map data were assembled as a digital database using ARC/INFO to enable wider applications than traditional paper-product geologic maps and to provide for efficient meshing with other digital data bases prepared by the U.S. Geological Survey's Southern California Areal Mapping Project.

  1. Evolution of salt and hydrocarbon migration: Sweet Lake area, Cameron Parish, Louisiana

    SciTech Connect

    Spencer, J.A.; Sharpe, C.L.

    1996-09-01

    The interpretation of seismic, gravity, and well data in northern Cameron Parish, Louisiana suggest that lateral salt flow has influenced the area`s structural evolution, depositional patterns, and hydrocarbon migration. Sweet Lake Field has produced over 46 MMBO and 15 BCFG from Middle Miocene deltaic sands. The structural closure is a downthrown anticline on a fault controlled by the underlying salt feature. Sweet Lake Field overlies an allochthonous salt mass that was probably once part of an ancestral salt ridge extending from Hackberry to Big Lake fields. Nine wells encountering top of salt and several seismic lines define a detached salt feature underlying over twenty square miles at depths from 8500-18,000 ft. Salt withdrawal in the East Hackberry-Big Lake area influenced the depositional patterns of the Oligocene lower Hackberry channel systems. Progradation of thick Middle Oligocene Camerina (A) and Miogypsinoides sands into the area caused salt thinning and withdrawal resulting in the development and orientation of the large Marginulina-Miogypsinoides growth fault northwest of Sweet Lake. Additional evidence for the southeast trend of the salt is a well approximately two miles southeast of Sweet Lake which encountered salt at approximately 19,800 ft. High quality 2-D and 3-D seismic data will continue to enhance the regional understanding of the evolving salt structures in the onshore Gulf Coast and the local understanding of hydrocarbon migration. Additional examples of lateral salt flow will be recognized and some may prove to have subsalt hydrocarbon potential.

  2. A new species of Phosocephala Townsend, 1908 (Diptera: Tachinidae) from Area de Conservación Guanacaste in northwestern Costa Rica

    PubMed Central

    Wood, D. Monty; Smith, M. Alex; Janzen, Daniel H; Hallwachs, Winnie; Dapkey, Tanya

    2016-01-01

    Abstract Background We describe a new species of Phosocephala Townsend, and provide a new collection record, and description of the previously unknown male, of Phosocephala metallica Townsend, from Area de Conservación Guanacaste (ACG), northwestern Costa Rica. All ACG specimens were reared from wild-caught Lepidoptera larvae (Lepidoptera: Erebidae, Nolidae). We provide a concise description of both species using morphology, life history, molecular data, and photographic documentation. The new species is authored and described by Fleming and Wood. New information Phosocephala alexanderi sp. n. PMID:27226748

  3. Orientation study of the Lake Sunapee area, New Hampshire. National Uranium Resource Evaluation Program

    SciTech Connect

    Karfunkel, B. S.; Sargent, K. A.

    1982-08-01

    An orientation study was conducted in the area of Lake Sunapee, New Hampshire, in preparation for a hydrogeochemical and stream sediment reconnaissance in glacial terrain. The study was carried out by the Savannah River Laboratory as part of the National Uranium Resource Evaluation (NURE). Ground water, lake water, stream water, lake sediment, and stream sediment samples were collected at 188 sites. The concentrations of uranium and other elements were determined by neutron activation analysis. This report is issued in draft form, without detailed technical and copy editing. This was done to make the report available to the public before the end of the NURE program.

  4. Research in the Geysers-Clear Lake geothermal area, Northern California

    USGS Publications Warehouse

    1981-01-01

    The Geysers-Clear Lake area is one of two places in the world where major vapor-dominated hydrothermal reservoirs are commercially exploited for electric power production. Because energy can be extracted more efficiently from steam than from hot water, vapor-dominated systems are preferable for electric power generation, although most geothermal electric power facilities tap water-dominated systems. The Geysers- Clear Lake geothermal system has therefore been of great interest to the geothermal industry.

  5. 75 FR 41512 - Draft Environmental Impact Statement/General Management Plan; Ross Lake National Recreation Area...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-16

    ...Pursuant to Sec. 102(2)(C) of the National Environmental Policy Act of 1969 (Pub. L. 91-190, as amended), and the Council on Environmental Quality Regulations (40 CFR part 1500-1508), the National Park Service (NPS), Department of the Interior, has prepared a draft environmental impact statement for the proposed General Management Plan (GMP) for Ross Lake National Recreation Area (Ross Lake......

  6. Surficial geologic map of the Red Rock Lakes area, southwest Montana

    USGS Publications Warehouse

    Pierce, Kenneth L.; Chesley-Preston, Tara L.; Sojda, Richard L.

    2014-01-01

    The Centennial Valley and Centennial Range continue to be formed by ongoing displacement on the Centennial fault. The dominant fault movement is downward, creating space in the valley for lakes and the deposition of sediment. The Centennial Valley originally drained to the northeast through a canyon now represented by a chain of lakes starting with Elk Lake. Subsequently, large landslides blocked and dammed the drainage, which created Lake Centennial, in the Centennial Valley. Sediments deposited in this late Pleistocene lake underlie much of the valley floor and rest on permeable sand and gravel deposited when the valley drained to the northeast. Cold Pleistocene climates enhanced colluvial supply of gravelly sediment to mountain streams and high peak flows carried gravelly sediment into the valley. There, the lower gradient of the streams resulted in deposition of alluvial fans peripheral to Lake Centennial as the lake lowered through time to the level of the two present lakes. Pleistocene glaciers formed in the high Centennial Range, built glacial moraines, and also supplied glacial outwash to the alluvial fans. Winds from the west and south blew sand to the northeast side of the valley building up high dunes. The central part of the map area is flat, sloping to the west by only 0.6 meters in 13 kilometers (2 feet in 8 miles) to form a watery lowland. This lowland contains Upper and Lower Red Rock Lakes, many ponds, and peat lands inside the “water plane,” above which are somewhat steeper slopes. The permeable sands and gravels beneath Lake Centennial sediments provide a path for groundwater recharged from the adjacent uplands. This groundwater leaks upward through Lake Centennial sediments and sustains wetland vegetation into late summer. Upper and Lower Red Rock Lakes are formed by alluvial-fan dams. Alluvial fans converge from both the south and the north to form outlet thresholds that dam the two shallow lakes upstream. The surficial geology aids in

  7. Application of the inundation area—lake level rating curves constructed from the SRTM DEM to retrieving lake levels from satellite measured inundation areas

    NASA Astrophysics Data System (ADS)

    Pan, Feifei; Liao, Jingjuan; Li, Xinwu; Guo, Huadong

    2013-03-01

    Remote sensing technology has great potential for measuring lake inundation areas and lake levels, and providing important lake water quantity and quality information which can be used for improving our understanding of climate change impacts on the global water cycle, and assessing the influence of the projected future climate change on the global water resources. One remote sensing approach is to estimate lake level from satellite measured inundation area based on the inundation area—lake level rating (IALLR) curves. However, this approach is not easy to implement because of a lack of data for constructing the IALLR curves. In this study, an innovative and robust approach to construct the IALLR curves from the digital elevation model (DEM) data collected during the Shuttle Radar Topography Mission (SRTM) was developed and tested. It was shown that the IALLR curves derived from the SRTM DEM data could be used to retrieve lake level from satellite measured inundation area. Applying the constructed IALLR curve to the estimated inundation areas from 16 Landsat Thematic Mapper (TM) images, 16 lake levels of Lake Champlain in Vermont were obtained. The root mean square error (RMSE) of the estimated lake levels compared to the observed water levels at the U.S. Geological Survey (USGS) gauging station (04294500) at Burlington, Vermont is about 0.12 m.

  8. Geohydrologic reconnaissance of Lake Mead National Recreation Area; Las Vegas Wash to Virgin River, Nevada

    USGS Publications Warehouse

    Laney, R.L.; Bales, J.T.

    1996-01-01

    This study is the last of a series of eight geohydrologic reconnaissance studies that were done in the Lake Mead National Recreation Area. The studies were done to evaluate the water resources in the recreation area and to identify areas having potential for the development of water supplies that would be adequate for marinas and campgrounds. The study area includes about 250 square miles north of Lake Mead from Las Vegas Wash to the Virgin River (Overton Arm), Nevada. Volcanic rocks, consolidated sedimentary rocks, and unconsolidated to semiconsolidated sedimentary rocks underlie the area. Surface-water sources include the Colorado River, Virgin River, Muddy River, and Las Vegas Wash. Elsewhere in the area, streamflow is meager and extremely variable. Ground water originates from four sources: (1) subsurface flow in local basins, (2) infiltration of water from Lake Mead into permeable rocks near the lake, (3) subsurface flow in valleys of perennial streams, and (4) subsurface flow in consolidated rocks of the Muddy Mountains. The quantity of water from Lake Mead that has saturated rocks adjacent to the lake probably is greater than the quantity of ground water from all the Other sources. Rocks saturated by water from the lake probably extend less than 0.5 mileinland from the lake shore. The quality of virtually all the ground water in the area is not acceptable for drinking purposes. The most favorable areas for obtaining ground water are those underlain by the coarse-grained deposits of the older alluvium and the younger alluvium adjacent to Lake Mead. The least favorable areas are those underlain by the mudstone facies of the Muddy Creek Formation and fine-grained rocks of the Horse Spring Formation. Four areas identified as having potential for ground-water development are (1) near Overton Beach, (2) west of Callville Bay, (3) near Middle Point, and (4) in the lower Moapa Valley. Usable quantities of water probably can be obtained at these sites, but the

  9. Paleoenvironmental reconstructions of Nettilling Lake area (Baffin Island, Nunavut): A multi-proxy analysis.

    NASA Astrophysics Data System (ADS)

    Beaudoin, Anne; Pienitz, Reinhard; Francus, Pierre; Zdanowicz, Christian; St-Onge, Guillaume

    2014-05-01

    The paleoclimate and paleolimnological history of several Arctic regions remains poorly known. This is the case for the area around Nettilling Lake (Baffin Island, Nunavut), the largest lake of the Canadian Arctic Archipelago. To reconstruct the past environmental history of this area, a highly innovative multi-proxy approach combining physical, magnetic, chemical and biological properties preserved in lake sediments was used. One particular goal of this study was to investigate the possible coupling between sedimentation processes observed in the lake and melt rates of nearby Penny Ice Cap. A 1-m long sediment core was retrieved from a small bay in the northeastern part of Nettilling Lake during the summer of 2010. This sampling area was chosen based on the hypothesis that incoming glacial meltwaters from Penny Ice Cap would leave a strong climate-modulated signal that would be reflected in the sedimentary sequence. The core was analyzed by both non-destructive (X-radiography (X-ray), microfluorescence-X (µ-XRF), magnetic susceptibility) and destructive (Loss On Ignition, grain size, water content, thin sections, diatoms) techniques. Radiometric AMS 14C and 210Pb/137Cs age determinations, as well as paleomagnetic measurements, were used to develop the core chronology, yielding an estimated bottom age of approximately 1365 AD. The sedimentation rate (0.15 cm.yr-1) in Nettilling Lake was found to be high compared to other Arctic lakes, due to inputs of highly turbid meltwaters from Penny Ice Cap with high suspended sediment loads. Significant correlations were found between geochemical profiles of elements linked to detrital inputs (Si, Ti, K, Ca) and melt rates from Penny Ice Cap since the 19th century. This suggests that variations in detrital elements in Nettilling Lake sediments might be used as an indirect indicator of regional climate fluctuations (e.g., summer temperatures) that determine glacier melt rates.

  10. Lake

    ERIC Educational Resources Information Center

    Wien, Carol Anne

    2008-01-01

    The lake is blue black and deep. It is a glaciated finger lake, clawed out of rock when ice retracted across Nova Scotia in a northerly direction during the last ice age. The lake is narrow, a little over a mile long, and deep, 90 to 190 feet in places according to local lore, off the charts in others. The author loves to swim there, with a sense…

  11. 33 CFR 165.901 - Great Lakes-regulated navigation areas.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Great Lakes-regulated navigation areas. 165.901 Section 165.901 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY REGULATED NAVIGATION AREAS AND LIMITED ACCESS...

  12. 33 CFR 165.901 - Great Lakes-regulated navigation areas.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Great Lakes-regulated navigation areas. 165.901 Section 165.901 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY REGULATED NAVIGATION AREAS AND LIMITED ACCESS...

  13. 33 CFR 165.901 - Great Lakes-regulated navigation areas.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Great Lakes-regulated navigation areas. 165.901 Section 165.901 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY REGULATED NAVIGATION AREAS AND LIMITED ACCESS...

  14. 33 CFR 165.901 - Great Lakes-regulated navigation areas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Great Lakes-regulated navigation areas. 165.901 Section 165.901 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY REGULATED NAVIGATION AREAS AND LIMITED ACCESS...

  15. Results of a detailed infill lake-sediment survey in the Snow Lake area: Evaluation and comparison of grab sample and short core data

    USGS Publications Warehouse

    Friske, P.W.B.

    1996-01-01

    As part of the Exploration Science and Technology Initiative (EXTECH) program a detailed infill lake-sediment and water survey was undertaken in the Snow Lake area during the fall of 1991. This involved the collection of 346 lake sediment grab samples and concomitant waters. In 1993, additional work was undertaken involving the collection of 23 short cores from selected grab sample sites. The primary objectives of the infill survey and short core work were to: 1) evaluate the effectiveness of lake sediment geochemistry in detecting known mineralization in the Snow Lake area; 2) evaluate and develop new approaches in the use of lake sediment geochemistry; and, 3) define, if possible, new exploration targets. At most sites, data from the cores verify the original grab sample results. However, at a few sites the original anomalous grab sample results are interpreted as being related to contamination as opposed to naturally elevated levels. An unusually thick sequence of contaminated surface sediments with extremely high concentrations of trace metals is a likely contributing factor, a condition which is restricted to lakes in the immediate vicinity of local anthropogenic activity. Collection of lake cores provides a useful new approach to the follow-up of grab sample data and to the application of lake sediment geochemistry, particularly in areas with significant local contamination. Much of the known mineralization in the area is clearly reflected by the lake sediment data. Character of the anomalies mirror the composition of the nearby mineralization. The lake sediment data also identify a number of areas that warrant further investigation, several of which are discussed.

  16. Changes in the area of inland lakes in arid regions of central Asia during the past 30 years.

    PubMed

    Bai, Jie; Chen, Xi; Li, Junli; Yang, Liao; Fang, Hui

    2011-07-01

    Inland lakes are major surface water resource in arid regions of Central Asia. The area changes in these lakes have been proved to be the results of regional climate changes and recent human activities. This study aimed at investigating the area variations of the nine major lakes in Central Asia over the last 30 years. Firstly, multi-temporal Landsat imagery in 1975, 1990, 1999, and 2007 were used to delineate lake extents automatically based on Normalized Difference Water Index (NDWI) threshold segmentation, then lake area variations were detailed in three decades and the mechanism of these changes was analyzed with meteorological data and hydrological data. The results indicated that the total surface areas of these nine lakes had decreased from 91,402.06 km(2) to 46,049.23 km(2) during 1975-2007, accounting for 49.62% of their original area of 1975. Tail-end lakes in flat areas had shrunk dramatically as they were induced by both climate changes and human impacts, while alpine lakes remained relatively stable due to the small precipitation variations. With different water usage of river outlets, the variations of open lakes were more flexible than those of other two types. According to comprehensive analyses, different types of inland lakes presented different trends of area changes under the background of global warming effects in Central Asia, which showed that the increased human activities had broken the balance of water cycles in this region. PMID:20830516

  17. Lake surface area variation and its responses to climatic change in Yamzhog Yumco Basin, South Tibet during 1970-2010

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Tian, Y.; Sun, R.

    2015-12-01

    The research on lake extraction from multi-source and multi-temporal satellite images and the lake size variation can provide reliable method and indispensable information to deepen the understanding about alpine lake changes with the accelerating warming. With field survey experience in the Yamzhog Yumco Basin, South Tibet, the outlines of five lakes (i.e., Yamzhog Yumco, Chen Co, Kongmu Co, Bajiu Co and Puma Yumco) were delineated by the adoption of 42 scenes of satellite images from Landsat, CBERS and HJ from 1970 to 2010, basing on which the responses of alpine lakes to climate change at different timescales were explored. The results are summarized as follows. (1) The seasonal fluctuation of lake surface area was similar with different trend for the five alpine lakes. As for the last 41 years, the annual variation of lake surface area exhibited two kinds of patterns for the five alpine lakes. And the Yamzhog Yumco declined by 9.41%, while the rest four lakes expanded. (2) The responses of alpine lakes to climate change rely on different timescale and water replenishment types. On the one hand, the precipitation change was the predominant driving forces for the seasonal fluctuation and variation trend of lake size, and the rising temperature accounted for the inter-annual lake surface variation. On the other hand, the two kinds of alpine lakes behaviors were well correspondent with the warming temperature over the Qinghai-Tibetan Plateau. The lakes supplied mainly by precipitation shrunk as a result of increased evaporation, and lakes supplied mainly by glacier and snow meltwater, however, expanded because of the remarkable glacier recession. (3) The quantification of hydrological components would hopefully be improved, according to uncertainties analysis, with the adoption of microwave satellite images and higher resolution ones to disclose the interaction mechanism among climate, glacier, and lake in alpine regions.

  18. Geochemical evolution of groundwater in the Mud Lake area, eastern Idaho, USA

    USGS Publications Warehouse

    Rattray, Gordon W.

    2015-01-01

    Groundwater with elevated dissolved-solids concentrations—containing large concentrations of chloride, sodium, sulfate, and calcium—is present in the Mud Lake area of Eastern Idaho. The source of these solutes is unknown; however, an understanding of the geochemical sources and processes controlling their presence in groundwater in the Mud Lake area is needed to better understand the geochemical sources and processes controlling the water quality of groundwater at the Idaho National Laboratory. The geochemical sources and processes controlling the water quality of groundwater in the Mud Lake area were determined by investigating the geology, hydrology, land use, and groundwater geochemistry in the Mud Lake area, proposing sources for solutes, and testing the proposed sources through geochemical modeling with PHREEQC. Modeling indicated that sources of water to the eastern Snake River Plain aquifer were groundwater from the Beaverhead Mountains and the Camas Creek drainage basin; surface water from Medicine Lodge and Camas Creeks, Mud Lake, and irrigation water; and upward flow of geothermal water from beneath the aquifer. Mixing of groundwater with surface water or other groundwater occurred throughout the aquifer. Carbonate reactions, silicate weathering, and dissolution of evaporite minerals and fertilizer explain most of the changes in chemistry in the aquifer. Redox reactions, cation exchange, and evaporation were locally important. The source of large concentrations of chloride, sodium, sulfate, and calcium was evaporite deposits in the unsaturated zone associated with Pleistocene Lake Terreton. Large amounts of chloride, sodium, sulfate, and calcium are added to groundwater from irrigation water infiltrating through lake bed sediments containing evaporite deposits and the resultant dissolution of gypsum, halite, sylvite, and bischofite.

  19. Evaluation of the effects of the Lake Audubon on ground- and surface-water levels in the Lake Nettie area, eastern McLean County, North Dakota

    USGS Publications Warehouse

    Armstrong, C.A.

    1983-01-01

    Flooding of some roads and agricultural lands has occurred in the Lake Nettie area of eastern McLean County. Part of the flooding was caused by the raising of the level of Lake Audubon to an elevation of 1,848 feet and the construction and filling of the McClusky Canal. Water levels have risen in the Lake Nettie aquifer as a result of raising the level of Lake Audubon. As of 1982, water levels have risen as much as 4 feet in the lower unit of the Lake Nettie aquifer and between 1 and 2 feet in the upper unit of the Lake Nettie aquifer, which is hydraulically connected to Lake Nettie and Crooked Lake. Water levels have risen in the Turtle Lake aquifer both as a result of raising the water level in Lake Audubon and the filling of McClusky Canal. Water levels have risen as much as 6 feet near the canal, but generally are less than 1 foot higher at distances of about 0.5 mile. (USGS)

  20. Late pleistocene and holocene history of the lakes in the Kola Peninsula, Karelia and the North-Western part of the East European plain

    NASA Astrophysics Data System (ADS)

    Davydova, N.; Servant-Vildary, S.

    The paper reviews the work on paleolimnology in parts of the FSU over the last 40 years. It presents a short review of The History of the Lakes of the East European Plain, one of the books of the series The History of Lakes published by the Institute of Lake Research of the Russian Academy of Sciences. It describes the Late Pleistocene and Holocene history of these lakes based mainly on the study of lacustrine sediments. Amongst the samples Lake Nero near Moscow which is located near the marginal zone of the last glaciation, and includes records that go back as early as 190,000 BP. The main elements of lake evolution are shown in different territories: Byelorussia; Baltic countries; Karelia; and the Kola Peninsula. Special attention is given to palaeolimnological data because its use for Holocene and Late Pleistocene palaeoclimate reconstructions.

  1. Robust Lake Level Extraction in Mountainous Areas By Retracking Cryosat Sarin Mode Waveforms.

    NASA Astrophysics Data System (ADS)

    Kleinherenbrink, M.; Ditmar, P.; Lindenbergh, R.

    2014-12-01

    Since the beginning of the 1990s, lake levels can be monitored using satellite altimetry.This is notably an advantage for lakes located in remote areas, where no gauges are present.Two disadvantages of traditional satellite altimetry however are the limited number of ground tracks and the pulse limited footprint size.In 2010 Cryosat was launched with onboard a SAR Interferometric Radar ALtimeter (SIRAL), which has a dense ground track spacing of 7-8 km and a along-track resolution of approximately 300 m in the SAR Interferometric (SARIn) mode.This potentially enables Cryosat to sample more lakes and obtain more reliable lake levels in near-shore regions.Still, the accuracy and robustness of standard level 2 data is limited due to pollution of the waveform in near-shore regions.We propose therefore to actively extract the water surface by a novel retracking algorithm based on cross-correlation of observed level 1b waveforms with a generic simulated waveform.As a result, we obtain multiple elevations per waveform.As the water level is contributing to each consecutive waveform over the lake, it can efficiently be extracted using a majority voting scheme.By comparing the lake levels to those obtained with Jason-2 over Lake Nasser an RMS of differences of 0.30 m is found.After this validation step, we applied the procedure to lakes in Tian Shan and Tibet.In these areas 125 lakes are measured at least four times in two years, of which 30 are even sampled ten times in two years and 16 more than twenty times.For the ones sampled more than twenty times an additional slope in the water surface could be estimated, which can be an effect of prevailing winds or errors in the geoid model.Ultimately, we found a negative water balance in the natural lakes in Tian Shan and a positive balance in Tibet between February 2012 and February 2014.These results clearly demonstrate the potential of Cryosat, as previous radar altimetry missions were only able to sample about 70 lakes over

  2. The significance of migrant Fulani and human trypanosomiasis in Kainji Lake area of Nigeria.

    PubMed

    Adekolu-John, E O

    1978-09-01

    The transhumance-route followed by the Fulani around Lake Kainji area of Nigeria is presented. Between January and February 1977 130 Fulanis were interviewed at different locations. Most respondents were between 20-60 years of age. In addition to cattle rearing, farming is practised among the Fulanis interviewed at Kaiama and Olli. Those interviewed at Faku practised pastoral transhumance. Less than 15% of the respondents had previous knowledge of human sleeping sickness. Although examination of blood films (thin and thick) did not reveal any blood trypanosome, the transhumance pastoral mobility will be an important factor in any outbreak of human trypanosomiasis around Kainji Lake area in future. PMID:734753

  3. Increased atmospheric deposition of mercury in reference lakes near major urban areas

    USGS Publications Warehouse

    Van Metre, P.C.

    2012-01-01

    Atmospheric deposition of Hg is the predominant pathway for Hg to reach sensitive ecosystems, but the importance of emissions on near-field deposition remains unclear. To better understand spatial variability in Hg deposition, mercury concentrations were analyzed in sediment cores from 12 lakes with undeveloped watersheds near to (<50 km) and remote from (>150 km) several major urban areas in the United States. Background and focusing corrected Hg fluxes and flux ratios (modern to background) in the near-urban lakes (68 ?? 6.9 ??g m -2 yr -1 and 9.8 ?? 4.8, respectively) greatly exceed those in the remote lakes (14 ?? 9.3 ??g m -2 yr -1 and 3.5 ?? 1.0) and the fluxes are strongly related to distance from the nearest major urban area (r 2 = 0.87) and to population and Hg emissions within 50-100 km of the lakes. Comparison to monitored wet deposition suggests that dry deposition is a major contributor of Hg to lakes near major urban areas. ?? 2011 Elsevier Ltd. All rights reserved.

  4. Salt Lake City, Utah

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Salt Lake City, Utah, will host the 2002 Winter Olympic Games. The city is located on the southeastern shore of the Great Salt Lake and sits to the west of the Wasatch Mountains, which rise more than 3,500 meters (10,000 feet) above sea level. The city was first settled in 1847 by pioneers seeking relief from religious persecution. Today Salt Lake City, the capital of Utah, is home to more than 170,000 residents. This true-color image of Salt Lake City was acquired by the Enhanced Thematic Mapper Plus (ETM+), flying aboard Landsat 7, on May 26, 2000. The southeastern tip of the Great Salt Lake is visible in the upper left of the image. The furrowed green and brown landscape running north-south is a portion of the Wasatch Mountains, some of which are snow-capped (white pixels). The greyish pixels in the center of the image show the developed areas of the city. A number of water reservoirs can be seen east of the mountain range. Salt Lake City International Airport is visible on the northwestern edge of the city. About 20 miles south of the airport is the Bingham Canyon Copper Mine (tan pixels), the world's largest open pit excavation. See also this MODIS image of Utah. Image courtesy NASA Landsat7 Science Team and USGS Eros Data Center

  5. Geohydrologic reconnaissance of Lake Mead National Recreation Area; Las Vegas Wash to Opal Mountain, Nevada

    USGS Publications Warehouse

    Laney, R.L.

    1981-01-01

    The study is a geohydrologic reconnaissance of about 170 square miles in the Lake Mead National Recreation Area from Las Vegas Wash to Opal Mountain, Nevada. The study is one of a series that describes the geohydrology of the recreation area and that indentifies areas where water supplies can be developed. Precipitation in this arid area is about 5 inches per year. Streamflow is seasonal and extremely variable except for that in the Colorado River, which adjoins the area. Pan evaporation is more than 20 times greater than precipitation; therefore, regional ground-water supplies are meager except near the Colorado River, Lake Mead, and Lake Mohave. Large ground-water supplies can be developed near the river and lakes, and much smaller supplies may be obtained in a few favorable locations farther from the river and lakes. Ground water in most of the areas probably contains more than 1,000 milligrams per liter of dissolved solids, but water that contains less than 1,000 milligrams per liter of dissolved solids can be obtained within about 1 mile of the lakes. Crystalline rocks of metamorphic, intrusive and volcanic origin crop out in the area. These rocks are overlain by conglomerate and mudstone of the Muddy Creek Formation, gravel and conglomerate of the older alluvium, and sand and gravel of the Chemehuevi Formation and younger alluvium. The crystalline rocks, where sufficiently fractured, yield water to springs and would yield small amounts of water to favorably located wells. The poorly cemented and more permeable beds of the older alluvium, Chemehuevi Formation, and younger alluvium are the better potential aquifers, particularly along the Colorado River and Lakes Mead and Mohave. Thermal springs in the gorge of the Colorado River south of Hoover Dam discharge at least 2,580 acre-feet per year of water from the volcanic rocks and metamorphic and plutonic rocks. The discharge is much greater than could be infiltrated in the drainage basin above the springs

  6. Changes in surface area of the Böön Tsagaan and Orog lakes (Mongolia, Valley of the Lakes, 1974-2013) compared to climate and permafrost changes

    NASA Astrophysics Data System (ADS)

    Szumińska, Danuta

    2016-07-01

    The main aim of the study is the analysis of changes in surface area of lake Böön Tsagaan (45°35‧N, 99°8‧E) and lake Orog (45°3‧N, 100°44‧E) taking place in the last 40 years in the context of climate conditions and permafrost degradation. The lakes, located in Central Mongolia, at the borderline of permafrost range are fed predominantly by river waters and groundwater from the surrounding mountain areas, characterized by continuous and discontinuous permafrost occurrence - mostly the Khangai. The analysis of the Böön Tsagaan and Orog lake surface area in 1974-2013 was conducted based on satellite images, whereas climate conditions were analysed using the NOAA climate data and CRU dataset. Principal Component Analysis (PCA) was used to study the relationship patterns between the climatic factors and changes in the surface area of the lakes. A tendency for a decrease in surface area, intermittent with short episodes of resupply, was observed in both studied lakes. Climate changes recorded in the analysed period had both direct and indirect impacts on water supply to lakes. Taking into account the results of PCA analysis, the most significant factors include: fluctuation of annual precipitation, increase in air temperature and thickness of snow cover. The extended duration of snow cover in the last decades of the 20th century may constitute a key factor in relation to permafrost degradation.

  7. Urmia Lake (Northwest Iran): a brief review

    PubMed Central

    Eimanifar, Amin; Mohebbi, Feridon

    2007-01-01

    Lake Urmia (or Ormiyeh) is one of the largest hypersaline lakes in the world and the habitat of a unique bisexual Artemia species (A. urmiana). Despite this, and several other values of the lake, little literature on it has been published. The present paper is an attempt to provide a brief review on various aspects of the lake. Urmia Lake, located in northwestern Iran, is an oligotrophic lake of thalassohaline origin with a total surface area between 4750 and 6100 km2 and a maximum depth of 16 m at an altitude of 1250 m. The lake is divided into north and south parts separated by a causeway in which a 1500-m gap provides little exchange of water between the two parts. Due to drought and increased demands for agricultural water in the lake's basin, the salinity of the lake has risen to more than 300 g/L during recent years, and large areas of the lake bed have been desiccated. Therefore, management and conservation of this incomparable ecosystem should be considered to improve the current condition by fisheries research institutes. PMID:17506897

  8. Mineral resources of the Henry's Lake Wilderness Study Area, Fremont County, Idaho

    SciTech Connect

    Tysdal, R.G. ); Peters, T.J. )

    1988-01-01

    The authors report on the 350-acre Henry's Lake Wilderness Study Area in the southern part of the Madison Range. Fremont County, Idaho, and is about 17 miles north of the hamlet of Islan Park. The southwestern part of the wilderness study area, along the Madison Range Fault, is rated as having a moderate energy resource potential for geothermal water, and the remainder of the study area has a low potential for this resource.

  9. Contamination and Risk Assessment of Heavy Metals in Lake Bed Sediment of a Large Lake Scenic Area in China

    PubMed Central

    Wan, Li; Xu, Liang; Fu, Yongsheng

    2016-01-01

    The exposure of heavy metals to lake bed sediment of scenic areas may pose risks on aquatic ecosystems and human health, however very few studies on risk assessment have been reported for scenic areas. Accordingly, this study determined concentration levels, and assessed contamination characteristics and risks, of heavy metals in lake bed sediment of National Scenic Areas Songhuahu (NSAS) in China. The concentrations of Zn, Cr, Pb, Ni, and Cu were determined in 29 bed sediment samples. Results showed that the mean values of Zn, Cr, Pb, Ni, and Cu were 92.69, 90.73, 38.29, 46.77, and 49.44 mg/kg, respectively. Pearson correlation coefficients indicated that organic matter was a major factor influencing distribution of heavy metals. The results for enrichment factors indicated that contamination rates and anthropogenic inputs of single heavy metals decreased in the order Cu > Ni > Pb > Cr > Zn; results of Nemerow integrated pollution index suggested that 72.41% of sampling sites were exposed to low to moderately integrated pollution, and 27.59% of sampling sites were exposed to strongly integrated pollution. According to results for potential ecological risk index, ecological risks of single and all the heavy metals in bed sediment from all the sampling sites were low. Human risks were assessed with hazardous quotients, and the results suggested that exposure of heavy metals to bed sediment posed no or little risk to human health, and the pathway of ingestion significantly contributed to human health risks. PMID:27455296

  10. Contamination and Risk Assessment of Heavy Metals in Lake Bed Sediment of a Large Lake Scenic Area in China.

    PubMed

    Wan, Li; Xu, Liang; Fu, Yongsheng

    2016-01-01

    The exposure of heavy metals to lake bed sediment of scenic areas may pose risks on aquatic ecosystems and human health, however very few studies on risk assessment have been reported for scenic areas. Accordingly, this study determined concentration levels, and assessed contamination characteristics and risks, of heavy metals in lake bed sediment of National Scenic Areas Songhuahu (NSAS) in China. The concentrations of Zn, Cr, Pb, Ni, and Cu were determined in 29 bed sediment samples. Results showed that the mean values of Zn, Cr, Pb, Ni, and Cu were 92.69, 90.73, 38.29, 46.77, and 49.44 mg/kg, respectively. Pearson correlation coefficients indicated that organic matter was a major factor influencing distribution of heavy metals. The results for enrichment factors indicated that contamination rates and anthropogenic inputs of single heavy metals decreased in the order Cu > Ni > Pb > Cr > Zn; results of Nemerow integrated pollution index suggested that 72.41% of sampling sites were exposed to low to moderately integrated pollution, and 27.59% of sampling sites were exposed to strongly integrated pollution. According to results for potential ecological risk index, ecological risks of single and all the heavy metals in bed sediment from all the sampling sites were low. Human risks were assessed with hazardous quotients, and the results suggested that exposure of heavy metals to bed sediment posed no or little risk to human health, and the pathway of ingestion significantly contributed to human health risks. PMID:27455296

  11. Geohydrology and numerical simulation of the alluvium and terrace aquifer along the Beaver-North Canadian River from the Panhandle to Canton Lake, northwestern Oklahoma

    USGS Publications Warehouse

    Davis, Robert E.; Christenson, Scott C.

    1981-01-01

    A quantitative description of the hydrologic system in alluvium and terrace deposits along the Beaver-North Canadian River in northwestern Oklahoma is needed as a aid for planning and management of the aquifer. A two-dimensional finite-difference model was used to describe the aquifer and to predict the effects of future ground-water withdrawals. The aquifer principally consists of three geologic units: Alluvium with an average thickness of 30 feet, low terrace deposits with an average thickness of 50 feet, and high terrace deposits with an average thickness of 70 feet. A thin cover of dune sand overlies much of the area and provides an excellent catchment for recharge, but is generally unsaturated. Hydraulic conductivity of the aquifer ranges from 0 to 160 feet per day and average 59 feet per day. Specific yield is estimated to be 0.29. Recharge to the aquifer is approximately 1 inch annually. Under present conditions (1978), most discharge is the result of ground-water flow to the Beaver-North Canadian River at a rate of 36 cubic feet per second and to pumpage for public-supply, industrial, and irrigation use at a rate of 28 cubic feet per second. In 1978, the aquifer had an average saturated thickness of 31 feet and contained 4.07 million acre-feet of water. The model was used to predict future head response in the aquifer to various pumping stresses. For any one area, the pumping stress was applied until the saturated thickness for that area was less than 5 feet, at which time the pumping ceased. The results of the modeled projections show that if the aquifer is stressed from 1978 to 1993 at the 1977 pumpage rates and well distribution, the average saturated thickness will decrease 1.0 foot and the volume of water in storage will be 3.94 million acre-feet, or 97 percent of the 1978 volume. If the aquifer is stressed at this same rate until 2020, the average saturated thickness will decrease an additional 0.7 foot and the volume of water in storage will be 3

  12. Construction, geologic, and hydrologic data for observation wells in the Reelfoot Lake area, Tennessee and Kentucky

    USGS Publications Warehouse

    Bradley, M.W.

    1987-01-01

    Twenty-three observation wells were installed at 12 sites in the Reelfoot Lake area of Kentucky and Tennessee during July 1986. The wells were installed to supplement an existing water level network and to provide additional data on the hydraulic characteristics and vertical hydraulic gradients in the alluvial aquifer near Reelfoot Lake. Well yields ranged from less than 20 gallons per minute to about 140 gallons per minute. The specific capacities of the wells ranged from less than 1 to 17.1 gallons per minute per foot of drawdown. Dissolved-solids concentrations ranged from 153 to 475 milligrams per liter at six wells. Three lithological sequences were encountered during drilling. Deep clay and silty clay occurred near the southwest corner of Reelfoot Lake. Predominantly medium- to coarse-grained sand occurred below about 15 feet of silt and clay near the west and northwest sides of the Lake. Along the western limit of the study area, near Lake No. 9 and the Mississippi River, at least about 50 feet of silt and silty sand occurred below land surface. (USGS)

  13. Monitored landscape change of Lake Baiyangdian wetland with dynamic reed area based on remote sensing

    NASA Astrophysics Data System (ADS)

    Wang, Zhen; He, Lei; Zhang, Shengwei; Lei, Yuping

    2009-09-01

    Lake Baiyangdian, a largest wetland ecosystem in North China Plain, has dried up on seven occasions since the 1960s. In recent years, more than one billion of cubic meters of water from upstream reservoirs and Yellow river have been transported to the lake to rescue the shrinking wetlands. Since the Lake Baiyangdian was actually composed of 143 small lakes and more than 70 villages with large or small area of cropland, dynamic distribution of aquatic plants in wetland such as reed and associated growth condition of these allowed to monitor the changes of wetland landscape and water quality to support the policy applications of water conveyance and wetland environmental treatment and control. Assisted with ground survey analyses and Landsat TM image, the MODIS 250 m time series Normalized Difference Vegetation Index (NDVI), given its combination of medium spatial and high temporal resolution, were applied to detect the unique rapid growth stage of reed in the spring from adjacent crops such as winter wheat, cotton, and spring maize, of which has a similar phenology in development of leaf area index, and dynamic reed areas were mapped in recent decade. Landscape changes of the wetland were analyzed using maps of reed area and hydrological data.

  14. WATER QUALITY FROM OXBOW LAKES WITHIN THE MISSISSIPPI DELTA MANAGEMENT SYSTEMS EVALUATION AREA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objectives of this paper were to examine and document pre-management water quality conditions on three oxbow lakes and resulting changes following the implementation of Best Management Practices within the Mississippi Delta Management Systems Evaluation Area (MSEA). Experimental design of the Missi...

  15. Business Use of Small Computers in the Salt Lake City, Utah Area.

    ERIC Educational Resources Information Center

    Homer, Michael M.

    In July 1981, Utah Technical College (UTC) conducted a survey of businesses in the Salt Lake City area to gather information for the development of a curriculum integrating computer applications with business course instruction. The survey sought to determine the status and usage of current micro/mini computer equipment, future data processing…

  16. ATMOSPHERIC MERCURY IN THE LAKE MICHIGAN BASIN: INFLUENCE OF THE CHICAGO/GARY URBAN AREA

    EPA Science Inventory

    The relative importance of the Chicago/Gay urban area was investigated to determine its impact on atmospheric mercury (Hg) concentrations and wet deposition in the Lake Michigan basin. Event wet-only precipitation, total particulate, and vapor phase samples were collected for ...

  17. 33 CFR 334.845 - Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., Volk Field military exercise area located in Lake Michigan offshore from Manitowoc and Sheboygan... Air National Guard, Volk Field military exercise area located in Lake Michigan offshore from Manitowoc.... (b) The regulation. (1) During specific, infrequent periods when Military exercises will be...

  18. 33 CFR 334.845 - Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore from Manitowoc and Sheboygan... Air National Guard, Volk Field military exercise area located in Lake Michigan offshore from...

  19. 33 CFR 334.845 - Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore from Manitowoc and Sheboygan... Air National Guard, Volk Field military exercise area located in Lake Michigan offshore from...

  20. 33 CFR 334.845 - Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore from Manitowoc and Sheboygan... Air National Guard, Volk Field military exercise area located in Lake Michigan offshore from...

  1. 33 CFR 334.845 - Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore from Manitowoc and Sheboygan... Air National Guard, Volk Field military exercise area located in Lake Michigan offshore from...

  2. Spatial and Temporal Changes in the Number, and Area, of Permafrost Controlled Lakes in the Western Canadian Arctic

    NASA Astrophysics Data System (ADS)

    Marsh, P.; Pohl, S.; Onclin, C.; Russell, M.

    2006-12-01

    Previous studies have considered lake formation and drainage in the continuous permafrost areas of the Western Canadian Arctic (Mackay, 1990; Marsh et al., 2003), and "disappearing arctic lakes" in Siberia (Smith et al., 2005). Smith et al. (2005) suggested that "the ultimate effect of continued climate warming on high- latitude, permafrost-controlled lakes and wetlands may well be their widespread disappearance". Given the vast number of permafrost controlled lakes in many Arctic regions, these studies raise the concern that climate change will have significant impacts on these lakes, with many lakes disappearing from the landscape, and with significant implications to arctic hydrology and ecology. This paper will discuss changes in both the area and number of permafrost dominated lakes in the Mackenzie Delta region of the Canadian Western Arctic. Like many arctic regions, the Western Canadian Arctic has a vast number of lakes and ponds. These permafrost dominated lakes developed due to a complex interaction of climate, permafrost, and hydrology. Although it is well known that climate warming may (a) increase the size, and number, of lakes due to thermokarst processes, as well as (b) decrease the number of lakes due to lake drainage, the relative importance of each process is not well known and therefore the impact of climate change on permafrost dominated lakes is unknown. The sensitivity of these processes, and complex interaction with climate, is demonstrated by the process of rapid lake drainage. Such drainage is common in the Mackenzie Delta region, and occurs when lakes melt new drainage channels through ice rich permafrost, resulting in the complete, or partial, drainage of the lake in a few hours. The effect of climate change on rapid lake drainage is controlled by a number of processes, with each having a different response to changes in climate. For example: (i) warmer and snowier winters typically result in decreased ice wedge cracking and therefore

  3. Nine new species of Itaplectops (Diptera: Tachinidae) reared from caterpillars in Area de Conservación Guanacaste, northwestern Costa Rica, with a key to Itaplectops species

    PubMed Central

    Wood, D. Monty; Smith, M. Alex; Janzen, Daniel H.; Hallwachs, Winnie

    2015-01-01

    Abstract Nine new species of Itaplectops Townsend (Diptera: Tachinidae) are described from Area de Conservación Guanacaste (ACG), northwestern Costa Rica. All specimens have been reared from ­various species of ACG caterpillars in the families Limacodidae and Dalceridae. By combining morphological, photographic, and genetic barcode data we provide clear yet concise descriptions. The following nine new species are described in the genus Itaplectops: Itaplectops akselpalolai, Itaplectops anikenpalolae, Itaplectops argentifrons, Itaplectops aurifrons, Itaplectops ericpalolai, Itaplectops griseobasis, Itaplectops omissus, Itaplectops shellymcsweeneyae, Itaplectops tristanpalolai. We move Itaplectops to the tribe Uramyini from its original placement within the Blondeliini, and we discuss its systematic placement. We also provide a key differentiating the, genera of the tribe Uramyini as well as the known species of Itaplectops. PMID:26752964

  4. Ground motion measurement in the lake Mead (Nevada, USA) area by temporal analysis of multiple interferograms.

    NASA Astrophysics Data System (ADS)

    Cavalie, O.; Doin, M.; Lasserre, C.; Briole, P.

    2004-12-01

    SAR interferometry has proven to be a reliable method for detecting small displacements due to ground subsidence. In this study, we propose to measure ground motion around the lake Mead (Nevada, USA) using InSAR. This artificial lake has been filled with water in 1935. An earlier studie, based on levelling measurements, has shown that the lake impoundement has induced a subsidence of 17 centimeters (Kaufmann et al., 2000). This relaxation process is analogous to the postglacial rebound, but at a smaller scale. To quantify the deformation and constrain the crust and mantle rheological parameters in the lake area, we have analysed multiple interferograms (245) based on 45 ERS images between 1992 and 2001. The interferometric phase contains information about deformation occurring between two satellite passes, as well as satellite orbits errors, topographic, and atmospheric artefacts. The topographic signature is removed using the 3-arc seconds SRTM data. To correct for orbital errors, we remove a best fitting linear ramp. Atmospheric artefact, in our interferograms, are mainly due to the variation of water vapor vertical stratification between the two passes. This results in a interferometric phase correlation with altitude which we remove by minimization. These corrections are then refined through an iterative procedure and validated using data from global atmospheric models. Corrected interferograms are then inverted to solve for deformation using a method based on the large spatial coverage of coherent pixels, allowing to strengthen the signal to noise ratio (Schmidt and Burgmann, 2003). This data inversion provides a time series of the expected deformation in the lake Mead area. The analysis of the deformation evolution during the period covered by the ERS satellites (1992-2001) shows a correlation between the vertical motion and the water level changes. So, we observe a subsidence of up to 1.5 cm between 1996 and 1998, followed by an uplift due to the drop of the

  5. Regional geoid modeling in the area of subglacial Lake Vostok, Antarctica

    NASA Astrophysics Data System (ADS)

    Schwabe, Joachim; Ewert, Heiko; Scheinert, Mirko; Dietrich, Reinhard

    2014-04-01

    We present a geoid model for the area of Lake Vostok, Antarctica, from a combination of local airborne gravity, ice-surface and ice-thickness data and a lake bathymetry model. The topography data are used for residual terrain modeling (RTM) in a remove-restore approach together with GOCE satellite data. The quasigeoid is predicted by least-squares collocation (LSC) and subsequently converted to geoid heights. Special aspects of that method in presence of an ice sheet are discussed. It is well known that a body freely floating in water is in a state of hydrostatic equilibrium (HE). This usually applies, e.g., to ice shelves or sea ice. However, it has been shown that this is valid also for the ice sheet covering the subglacial Lake Vostok. Thus, we demonstrate the use of such a refined regional geoid model for glaciological and geophysical applications by means of the HE surface of that lake. The mean quadratic residual geoid signal (0.56 m) w.r.t. the GOCE background model exceeds the residual variations of the estimated apparent lake level (ALL) (0.26 m) within the central part of the lake. An approach considering the actual geopotential at the ALL has been derived and subsequently applied. In this context, downward continuation of the potential field within the ice sheet as well as the latitudinal tilt of off-geoid equipotential surfaces are discussed. In view of the accuracy of the ice-thickness measurements that dominate the total error budget of the estimated ALL these effects are negligible. Thus, the HE surface of subglacial lakes may safely be described by a constant height bias in small-scale regional applications. However, field continuation is significant with respect to the formal uncertainty of the quasigeoid, which is at the level of 5 cm given that accurate airborne gravity data (±2 mGal) are available.

  6. 36 CFR 7.48 - Lake Mead National Recreation Area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... defined in 33 CFR 110.127. (2) Temple Bar landing strip, located at approximate latitude 36°01′ N... the air in powerless flight is allowed except in harbors, swim beaches, developed areas, and in other... person may launch and operate a personal watercraft in park waters or beach a personal watercraft on...

  7. 36 CFR 7.48 - Lake Mead National Recreation Area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... defined in 33 CFR 110.127. (2) Temple Bar landing strip, located at approximate latitude 36°01′ N... the air in powerless flight is allowed except in harbors, swim beaches, developed areas, and in other... person may launch and operate a personal watercraft in park waters or beach a personal watercraft on...

  8. 36 CFR 7.48 - Lake Mead National Recreation Area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... defined in 33 CFR 110.127. (2) Temple Bar landing strip, located at approximate latitude 36°01′ N... the air in powerless flight is allowed except in harbors, swim beaches, developed areas, and in other... person may launch and operate a personal watercraft in park waters or beach a personal watercraft on...

  9. Canine fecal contamination in a metropolitan area (Milan, north-western Italy): prevalence of intestinal parasites and evaluation of health risks.

    PubMed

    Zanzani, Sergio Aurelio; Di Cerbo, Anna Rita; Gazzonis, Alessia Libera; Genchi, Marco; Rinaldi, Laura; Musella, Vincenzo; Cringoli, Giuseppe; Manfredi, Maria Teresa

    2014-01-01

    Intestinal parasites of dogs represent a serious threat to human health due to their zoonotic potential. Thus, metropolitan areas presenting high concentrations of pets and urban fecal contamination on public areas are at sanitary risk. Major aim of this survey was to determine prevalence of zoonotic parasites in dog fecal samples collected from public soil of Milan (north-western Italy). Differences in parasites prevalence distribution were explored by a geographical information system- (GIS-) based approach, and risk factors (human density, sizes of green parks, and dog areas) were considered. The metropolitan area was divided into 157 rectangular subareas and sampling was performed following a 1-kilometer straight transect. A total of 463 fecal samples were analyzed using centrifugation-flotation technique and ELISA to detect Giardia and Cryptosporidium coproantigens. A widespread fecal contamination of soil was highlighted, being fecal samples found in 86.8% of the subareas considered. The overall prevalence of intestinal parasites was 16.63%. Zoonotic parasites were found, such as Trichuris vulpis (3.67%), Toxocara canis (1.72%), Strongyloides stercoralis (0.86%), Ancylostomatidae (0.43%), and Dipylidium caninum (0.43%). Giardia duodenalis was the most prevalent zoonotic protozoa (11.06%), followed by Cryptosporidium (1.10%). Faeces from subareas characterized by broad green areas showed to be particularly prone to infection. PMID:25478583

  10. Canine Fecal Contamination in a Metropolitan Area (Milan, North-Western Italy): Prevalence of Intestinal Parasites and Evaluation of Health Risks

    PubMed Central

    Zanzani, Sergio Aurelio; Di Cerbo, Anna Rita; Gazzonis, Alessia Libera; Genchi, Marco; Rinaldi, Laura; Musella, Vincenzo; Cringoli, Giuseppe

    2014-01-01

    Intestinal parasites of dogs represent a serious threat to human health due to their zoonotic potential. Thus, metropolitan areas presenting high concentrations of pets and urban fecal contamination on public areas are at sanitary risk. Major aim of this survey was to determine prevalence of zoonotic parasites in dog fecal samples collected from public soil of Milan (north-western Italy). Differences in parasites prevalence distribution were explored by a geographical information system- (GIS-) based approach, and risk factors (human density, sizes of green parks, and dog areas) were considered. The metropolitan area was divided into 157 rectangular subareas and sampling was performed following a 1-kilometer straight transect. A total of 463 fecal samples were analyzed using centrifugation-flotation technique and ELISA to detect Giardia and Cryptosporidium coproantigens. A widespread fecal contamination of soil was highlighted, being fecal samples found in 86.8% of the subareas considered. The overall prevalence of intestinal parasites was 16.63%. Zoonotic parasites were found, such as Trichuris vulpis (3.67%), Toxocara canis (1.72%), Strongyloides stercoralis (0.86%), Ancylostomatidae (0.43%), and Dipylidium caninum (0.43%). Giardia duodenalis was the most prevalent zoonotic protozoa (11.06%), followed by Cryptosporidium (1.10%). Faeces from subareas characterized by broad green areas showed to be particularly prone to infection. PMID:25478583

  11. Crustal structure in the Falcón Basin area, northwestern Venezuela, from seismic and gravimetric evidence

    NASA Astrophysics Data System (ADS)

    Bezada, Maximiliano J.; Schmitz, Michael; Jácome, María Inés; Rodríguez, Josmat; Audemard, Franck; Izarra, Carlos; The Bolivar Active Seismic Working Group

    2008-05-01

    The Falcón Basin in northwestern Venezuela has a complex geological history driven by the interactions between the South American and Caribbean plates. Igneous intrusive bodies that outcrop along the axis of the basin have been associated with crustal thinning, and gravity modeling has shown evidence for a significantly thinned crust beneath the basin. In this study, crustal scale seismic refraction/wide-angle reflection data derived from onshore/offshore active seismic experiments are interpreted and forward-modeled to generate a P-wave velocity model for a ˜450 km long profile. The final model shows thinning of the crust beneath the Falcón Basin where depth to Moho decreases to 27 km from a value of 40 km about 100 km to the south. A deeper reflected phase on the offshore section is interpreted to be derived from the downgoing Caribbean slab. Velocity values were converted to density and the resulting gravimetric response was shown to be consistent with the regional gravity anomaly. The crustal thinning proposed here supports a rift origin for the Falcón Basin.

  12. Effects of climatic warming on Lakes of the central boreal forest

    SciTech Connect

    Schindler, D.W.; Beaty, K.G.; Fee, E.J.; Cruikshank, D.R.; DeBruyn, E.R.; Findlay, D.L.; Linsey, G.A.; Shearer, J.A.; Stainton, M.P.; Turner, M.A. )

    1990-11-16

    Twenty years of climatic, hydrologic, and ecological records for the Experimental Lakes Area of northwestern Ontario show that air and lake temperatures have increased by 2{degree}C and the length of the ice-free season has increased by 3 weeks. Higher than normal evaporation and lower than average precipitation have decreased rates of water renewal in lakes. Concentrations of most chemicals have increased in both lakes and streams because of decreased water renewal and forest fires in the catchments. In Lake 239, populations and diversity of phytoplankton also increased, but primary production showed no consistent trend. Increased wind velocities, increased transparency, and increased exposure to wind of lakes in burned catchments caused thermoclines to deepen. As a result, summer habitats for cold stenothermic organisms like lake trout and opossum shrimp decreased. Our observations may provide a preview of the effects of increased greenhouse warming on boreal lakes. 27 refs., 1 fig.

  13. The Deformation Features of Quartz Grains in the Sandstone of Taihu Lake Area: Taihu Lake Impact Origin Controversy

    NASA Astrophysics Data System (ADS)

    Xie, Z.; Dong, Y.; Zuo, S.

    2013-09-01

    Using deformation features in quartz grains to discuss Taihu Lake impact hypothesis. Results show that quartz deformation features are not typical shock-induced PDF. The hypothesis of impact origin of Taihu lake is not mature yet but still possible.

  14. Sequence stratigraphy of Late Pliocene and Pleistocene sediments of northwestern Green Canyon Area/western Ewing Bank, northern Gulf of Mexico

    SciTech Connect

    Martinez, R.E.; Weimer, P.

    1994-09-01

    Northwestern Green Canyon and Western Ewing Bank lease areas are characterized by complex faulting and salt deformation affecting the late Pliocene-Pleistocene sediments. The sequence stratigraphy has been studied using 1300 km of multifold seismic data, and 40 wells with biostratigraphy data (12 with high-resolution analysis). Fossil abundance and diversity curves were used to recognize condensed sections. Eight depositional sequences have been recognized (2.4, 1.9, 1.4, 0.8, 0.7, 0.5, and 0.4 Ma). Maximum thickness of these sediments is 6 km. Paleobathymetry indicates that sequences were deposited primarily in bathyal water depths. Most of the sediments are in the lowstand systems tracts and consist of basin-floor fans, slope fans, and prograding complexes. Thick blocky sand packages (basin-floor fan) are present in two major sequences (1.4 and 1.1 Ma) and represent potential reservoirs in the area. Transgressive and highstand systems tracts are fairly thin across the area and are thicker only in the younger sequences (< 0.5 Ma). The syndepositional structures play an important role in controlling the geometry and distribution of the depositional units, as well as creating structural highs for petroleum entrapment. Existing discoveries in the area include Green Canyon Blocks 6, 52, 184, and 228, and are associated primarily with amplitude anomalies on the flanks of salt structures and/or faults.

  15. Preliminary appraisal of ephemeral-streamflow characteristics as related to drainage area, active-channel width, and soils in northwestern New Mexico

    USGS Publications Warehouse

    Hejl, H.R., Jr.

    1980-01-01

    Regression equations are presented to predict ephemeral streamflow characteristics in the San Juan Basin in northwestern New Mexico. The standard error of estimate for predicting runoff for water year 1978 using drainage area as the independent variable was 152 percent. Indications are that reliable equations for predicating annual runoff can be developed and the standard error of estimate might be reduced significantly with additional years of record. The coefficient of regression when relating drainage area to runoff for water year 1978 was significant at the 1-percent level. Preliminary results also indicate it is feasible to predict streamflow characteristics using hyrologic soil-group classifications based on runoff potential. The standard error of estimate for predicting peak discharges with recurrence intervals of 2, 5, 10, 25, 50, and 100 years using active-channel width as the independent variable averaged about 50 percent, and the regression coefficient was significant at the 1-percent level. Using drainage area to predict peak discharges resulted in a standard error of estimate that averaged about 60 percent and a regression coefficient significant at the 5-percent level. The standard error of estimate averaged about 45 percent when active-channel width and drainage area were related to peak discharges in multiple regression analyses. (USGS)

  16. Ground Motion Measurement in the Lake Mead Area (Nevada, USA), by Temporal Analysis of Multiple Interferograms.

    NASA Astrophysics Data System (ADS)

    Doin, M.; Cavalie, O.; Lasserre, C.; Briole, P.

    2005-12-01

    SAR interferometry has proven to be a reliable method for detecting small displacements due to ground subsidence. In this study, we measure ground motion around the lake Mead (Nevada, USA) using InSAR. This artificial lake has been filled with water in 1935. An earlier study, based on leveling measurements, has shown that the load associated with lake impoundment has induced a delayed subsidence of 17 centimeters. This relaxation process has been argued to be due to viscous displacement in the uppermost mantle, analogous to the postglacial rebound, but at a smaller spatial scale and with a much lower viscous relaxation scale. To quantify the deformation and thus constrain the crust and mantle rheological parameters in the lake area, we analyse multiple interferograms (~280) based on 43 ERS images acquired between 1992 and 2001 and on 12 Envisat images acquired between 2003 and 2005. ERS-Envisat interferograms are performed to merge the two data sets in one time series. With baselines smaller than 300 m, all interferograms have a very good coherence due to the desert region. Most interferograms show strong atmospheric artefacts that are partly due to the variation of water vapor vertical stratification between two satellite passes. Tropospheric delay is computed for each interferogram using the correlation between phase and elevation far from the lake area. It is then inverted for each date of SAR images before interferograms correction. These corrections are validated using data from global atmospheric models (ERA40). Corrected interferograms are then inverted to solve for time series of the expected deformation in the lake Mead area . The linear inversion treats each pixel independently from its neighbours and use the data redundancy to reduce errors such as local decorrelations. Smoothing constraints added in the inversion efficiently eliminate local atmospheric artefacts. We obtain a time series of the expected deformation in the lake Mead area. The analysis of

  17. Landslide susceptibility in the Tully Valley area, Finger Lakes region, New York

    USGS Publications Warehouse

    Jager, Stefan; Wieczorek, Gerald E.

    1994-01-01

    As a consequence of a large landslide in the Tully Valley, Onondaga County, New York, an investigation was undertaken to determine the factors responsible for the landslide in order to develop a model for regional landslide susceptibility. The April 27, 1993 Tully Valley landslide occurred within glacial lake clays overlain by till and colluvium on gentle slopes of 9-12 degrees. The landslide was triggered by extreme climatic events of prolonged heavy rainfall combined with rapid melting of a winter snowpack. A photoinventory and field checking of landslides within a 415 km2 study area, including the Tully Valley, revealed small recently-active landslides and other large dormant prehistoric landslides, probably Pleistocene in age. Similar to the larger Tully Valley landslide, the smaller recently-active landslides occurred in red, glacial lake clays very likely triggered by seasonal rainfall. The large dormant landslides have been stable for long periods as evidenced by slope denudational processes that have modified the landslides. These old and ancient landslides correspond with proglacial lake levels during the Pleistocene, suggesting that either inundation or rapid drainage was responsible for triggering these landslides. A logistic regression analysis was performed within a Geographic Information System (GIS) environment to develop a model of landslide susceptibility for the Tully Valley study area. Presence of glacial clays, slope angle, and glacial lake levels were used as explanatory variables for landslide incidence. The spatial probability of landsliding, categorized as low, moderate and high, is portrayed within 90-m square cells on the susceptibility map.

  18. Calculation of Area and Volume for the North Part of Great Salt Lake, Utah

    USGS Publications Warehouse

    Baskin, Robert L.

    2006-01-01

    The U.S. Geological Survey, in cooperation with the Utah Department of Natural Resources, Division of Forestry, Fire, and State Lands, collected bathymetric data for the north part of Great Salt Lake during the spring and early summer of 2006 using a single-beam, high-definition fathometer and real-time differential global positioning system. About 5.2 million depth measurements were collected along more than 765 miles (1,230 kilometers) of survey transects. Sound-velocity profiles were obtained in conjunction with the bathymetric data to provide time-of-travel corrections to the depth calculations. Data were processed with commercial hydrographic software and exported into geographic information system (GIS) software for mapping and calculation of area and volume. Area and volume calculations show a maximum area of about 385,000 acres (1,560 square kilometers) and a maximum volume of about 5,693,000 acre-feet (about 7 cubic kilometers) at a water-surface altitude of 4,200 feet (1,280 meters). Minimum natural water-surface altitude of the north part of Great Salt Lake is just below 4,167 feet (1,270 meters) in the area just north of the Union Pacific railroad causeway halfway between Saline and the western edge of the lake. The north part of Great Salt Lake generally grades gradually to the west and north and is bounded by steep scarps along its eastern border. Calculations for area and volume are based on a low altitude of 4,167 feet (1,270 meters) to a high altitude of 4,200 feet (1,280 meters).

  19. Numerical simulation of ground-water flow through glacial deposits and crystalline bedrock in the Mirror Lake area, Grafton County, New Hampshire

    USGS Publications Warehouse

    Tiedeman, Claire R.; Goode, Daniel J.; Hsieh, P.A.

    1997-01-01

    recharge from precipitation to the water table is 26 to 28 cm/year. Hydraulic conductivities are 1.7 x 10-6 to 2.7 x 10-6 m/s for glacial deposits, about 3 x 10-7 m/s for bedrock beneath lower hillsides and valleys, and about 6x10-8 m/s for bedrock beneath upper hillsides and hilltops. Analysis of parameter uncertainty indicates that the above values are well constrained, at least within the context of regression analysis. In the regression, several attributes of the ground-water flow model are assumed perfectly known. The hydraulic conductivity for bedrock beneath upper hillsides and hilltops was determined from few data, and additional data are needed to further confirm this result. Model fit was not improved by introducing a 10-to-1 ration of horizontal-to-vertical anisotropy in the hydraulic conductivity of the glacial deposits, or by varying hydraulic conductivity with depth in the modeled part (uppermost 150m) of the bedrock. The calibrated model was used to delineate the Mirror Lake ground-water basin, defined as the volumes of subsurface through which ground water flows from the water table to Mirror Lake or its inlet streams. Results indicate that Mirror Lake and its inlet streams drain an area of ground-water recharge that is about 1.5 times the area of the surface-water basin. The ground-water basin extends far up the hillside on the northwestern part of the study area. Ground water from this area flows at depth under Norris Brook to discharge into Mirror Lake or its inlet streams. As a result, the Mirror Lake ground-water basin extends beneath the adjacent ground-water basin that drains into Norris Brook. Model simulation indicates that approximately 300,000 m3/year of precipitation recharges the Mirror Lake ground-water basin. About half the recharge enters the basin in areas where the simulated water table lies in glacial deposits; the other half enters the basin in areas where the simulated water table lies in be

  20. The Geysers-Clear Lake geothermal area, California - an updated geophysical perspective of heat sources

    USGS Publications Warehouse

    Stanley, W.D.; Blakely, R.J.

    1995-01-01

    The Geysers-Clear Lake geothermal area encompasses a large dry-steam production area in The Geysers field and a documented high-temperature, high-pressure, water-dominated system in the area largely south of Clear Lake, which has not been developed. An updated view is presented of the geological/geophysical complexities of the crust in this region in order to address key unanswered questions about the heat source and tectonics. Forward modeling, multidimensional inversions, and ideal body analysis of the gravity data, new electromagnetic sounding models, and arguments made from other geophysical data sets suggest that many of the geophysical anomalies have significant contributions from rock property and physical state variations in the upper 7 km and not from "magma' at greater depths. Regional tectonic and magmatic processes are analyzed to develop an updated scenario for pluton emplacement that differs substantially from earlier interpretations. In addition, a rationale is outlined for future exploration for geothermal resources in The Geysers-Clear Lake area. -from Authors

  1. Hyperspectral remote sensing of evaporate minerals and associated sediments in Lake Magadi area, Kenya

    NASA Astrophysics Data System (ADS)

    Kodikara, Gayantha R. L.; Woldai, Tsehaie; van Ruitenbeek, Frank J. A.; Kuria, Zack; van der Meer, Freek; Shepherd, Keith D.; van Hummel, G. J.

    2012-02-01

    Pleistocene to present evaporitic lacustrine sediments in Lake Magadi, East African Rift Valley, Kenya were studied and mapped using spectral remote sensing methods. This approach incorporated surface mineral mapping using space-borne hyperspectral Hyperion imagery together with laboratory analysis, including visible, near-infrared diffuse reflectance spectroscopy (VNIR) measurements and X-ray diffraction for selected rock and soil samples of the study area. The spectral signatures of Magadiite and Kenyaite, which have not been previously reported, were established and the spectral signatures of trona, chert series, volcanic tuff and the High Magadi bed were also analyzed. Image processing techniques, MNF (Minimum Noise Fraction) and MTMF (Mixture Tuned Matched Filtering) using a stratified approach (image analysis with and without the lake area), were used to enhance the mapping of evaporates. High Magadi beds, chert series and volcanic tuff were identified from the Hyperion image with an overall mapping accuracy of 84.3%. Even though, the spatial distribution of evaporites and sediments in Lake Magadi area change in response to climate variations, the mineralogy of this area has not been mapped recently. The results of this study shows the usefulness of the hypersspectral remote sensing to map the surface geology of this kind of environment and to locate promising sites for industrial open-pit trona mining in a qualitative and quantitative manner.

  2. Variability of rainfall over Lake Kariba catchment area in the Zambezi river basin, Zimbabwe

    NASA Astrophysics Data System (ADS)

    Muchuru, Shepherd; Botai, Joel O.; Botai, Christina M.; Landman, Willem A.; Adeola, Abiodun M.

    2016-04-01

    In this study, average monthly and annual rainfall totals recorded for the period 1970 to 2010 from a network of 13 stations across the Lake Kariba catchment area of the Zambezi river basin were analyzed in order to characterize the spatial-temporal variability of rainfall across the catchment area. In the analysis, the data were subjected to intervention and homogeneity analysis using the Cumulative Summation (CUSUM) technique and step change analysis using rank-sum test. Furthermore, rainfall variability was characterized by trend analysis using the non-parametric Mann-Kendall statistic. Additionally, the rainfall series were decomposed and the spectral characteristics derived using Cross Wavelet Transform (CWT) and Wavelet Coherence (WC) analysis. The advantage of using the wavelet-based parameters is that they vary in time and can therefore be used to quantitatively detect time-scale-dependent correlations and phase shifts between rainfall time series at various localized time-frequency scales. The annual and seasonal rainfall series were homogeneous and demonstrated no apparent significant shifts. According to the inhomogeneity classification, the rainfall series recorded across the Lake Kariba catchment area belonged to category A (useful) and B (doubtful), i.e., there were zero to one and two absolute tests rejecting the null hypothesis (at 5 % significance level), respectively. Lastly, the long-term variability of the rainfall series across the Lake Kariba catchment area exhibited non-significant positive and negative trends with coherent oscillatory modes that are constantly locked in phase in the Morlet wavelet space.

  3. National Surface Water Survey, western wilderness area lakes: environmental assessment. Draft

    SciTech Connect

    Not Available

    1985-03-01

    The US Environmental Protection Agency (EPA) is proposing to sample 498 lakes in federally designated wilderness areas and national parks during the western part of the National Surface Water Survey (NSW). The NSWS has been undertaken to provide high quality data for evaluating the nature and extent of acid deposition throughout the United States. Sampling protocols established for the national survey call for the use of helicopters to gain access to lakes for sampling. Helicopters have already been used in the eastern and midwestern parts of the survey. The US Forest Service (FS) and the National Park Service (NPS) will have to decide which sampling plan for wilderness areas, if any, can be approved under the Wilderness Act of 1964. This Environmental Assessment (EA) has been prepared to evaluate the environmental consequences of alternative means of gaining access to wilderness areas to meet the objectives of the NSWS. Based on this evaluation, EPA has reviewed the possible sampling alternatives and reached a conclusion on the preferred alternative. This assessment is being provided to the FS and the NPS for their use in evaluating the alternatives, including EPA's preferred one. As a result of its evaluation, EPA believes that wilderness area lakes should be included in the survey and that the preferred means of access is using helicopters. 94 references, 14 figures, 18 tables.

  4. [Genetic diversity of eukarytic microplankton in different areas of Lake Taihu].

    PubMed

    Chen, Mei-Jun; Kong, Fan-Xiang; Chen, Fei-Zhou; Xing, Peng

    2008-03-01

    The methods of DGGE and cloning/sequencing were used to study the diversity and community structures of small planktons (0.8 - 20 microm) in different areas of Lake Taihu. DGGE indicated that there were markly various fingerprints in different areas and the diversities were higher in areas with low trophic status than those with relatively high trophic status. There were 23, 24 DGGE bands in East Taihu and Gonghu Bay, respectively (Shannon index were 3.135 and 3.178) and 18 bands in both Meiliang Bay and Wuli Bay (Both shannon index were 2.890). The result of cloning/sequencing indicated that there was a high diversity of small planktons in Lake Taihu and most of them phototrophic flagellate, heterotrophic flagellate, ciliate and fungi. There were various community structures in the three different clone libraries. In Meilang Bay, 28.6% OTUs(operational taxonomic unit)belonged to heterotrophic flagellate, followed by Cryptophyta (22.9%) and Chrysophyta (14.3%). In Central Lake, 25.7% OTUs belonged to Chrysophyta, followed by heterotrophic flagellate (20.0%) and Cryptophyta (14.3 %). In East Taihu, ciliates were the dominant group and only a few heterotrophic flagellates (40.9%) were detected. In addition, fungi were relatively abundant (12.2%) in this area. PMID:18649542

  5. The effects of a dry sand layer on groundwater recharge in extremely arid areas: field study in the western Hexi Corridor of northwestern China

    NASA Astrophysics Data System (ADS)

    Sun, Peng; Ma, Jinzhu; Qi, Shi; Zhao, Wei; Zhu, Gaofeng

    2016-04-01

    Evaporation capacity is an important factor that cannot be ignored when judging whether extreme precipitation events will produce groundwater recharge. The evaporation layer's role in groundwater recharge was evaluated using a lysimeter simulation experiment in the desert area of Dunhuang, in the western part of the Hexi Corridor in northwestern China's Gansu Province. The annual precipitation in the study area is extremely low, averaging 38.87 mm during the 60-year study period, and daily pan evaporation amounts to 2,486 mm. Three simulated precipitation regimes (normal, 10 mm; ordinary annual maximum, 21 mm; and extreme, 31 mm) were used in the lysimeter simulation to allow monitoring of water movement and weighing to detect evaporative losses. The differences in soil-water content to a depth of 50 cm in the soil profile significantly affected rainfall infiltration during the initial stages of rainfall events. It was found that the presence of a dry 50-cm-deep sand layer was the key factor for "potential recharge" after the three rainfall events. Daily precipitation events less than 20 mm did not produce groundwater recharge because of the barrier effect created by the dry sand. Infiltration totaled 0.68 mm and penetrated to a depth below 50 cm with 31 mm of rainfall, representing potential recharge equivalent to 1.7 % of the rainfall. This suggests that only extreme precipitation events offer the possibility of recharge of groundwater in this extremely arid area.

  6. Use of environmental isotopes and hydrochemistry as indicators for the origin of groundwater resources in El Dabaa area, northwestern coastal zone of Egypt.

    PubMed

    Awad, M A; Hammad, F A; Aly, A I; Sadek, M A

    1994-03-01

    The EI-Dabaa area is located on the northwestern coastal zone of Egypt and is considered to be one of the most important regions for land reclamation and agriculture. In addition, it has been selected as a potential site for constructing Egypt's first nuclear power plant.In April 1989, 14 groundwater samples were collected from the area as well as collecting samples from the Mediterranean sea and from local rainwater. These samples were subjected to chemical and environmental isotope analyses. The results of the analyses for stable isotopes (oxygen-18 and deuterium) indicate that the main recharge source of the groundwater in El-Dabaa is the local precipitation during the rainy season. Variation of the environmental tritium content as well as in the chemical composition of both major cations (Na,K,Ca,Mg) and major anions (Cl,SO4,HCO3) between different groundwaters in the studied area reflect the high degree of inhomogeneity of the aquifer and different recharging conditions due to permeability of the water bearing formation.The chemical water type of the El-Dabaa groundwater is sodium sulphate (Na2SO4) and the SAR values illustrate the suitability of these groundwaters for agricultural purposes. PMID:24198175

  7. Comparison of three methods for long-term monitoring of boreal lake area using Landsat TM and ETM+ imagery

    USGS Publications Warehouse

    Roach, Jennifer K.; Griffith, Brad; Verbyla, David

    2012-01-01

    Programs to monitor lake area change are becoming increasingly important in high latitude regions, and their development often requires evaluating tradeoffs among different approaches in terms of accuracy of measurement, consistency across multiple users over long time periods, and efficiency. We compared three supervised methods for lake classification from Landsat imagery (density slicing, classification trees, and feature extraction). The accuracy of lake area and number estimates was evaluated relative to high-resolution aerial photography acquired within two days of satellite overpasses. The shortwave infrared band 5 was better at separating surface water from nonwater when used alone than when combined with other spectral bands. The simplest of the three methods, density slicing, performed best overall. The classification tree method resulted in the most omission errors (approx. 2x), feature extraction resulted in the most commission errors (approx. 4x), and density slicing had the least directional bias (approx. half of the lakes with overestimated area and half of the lakes with underestimated area). Feature extraction was the least consistent across training sets (i.e., large standard error among different training sets). Density slicing was the best of the three at classifying small lakes as evidenced by its lower optimal minimum lake size criterion of 5850 m2 compared with the other methods (8550 m2). Contrary to conventional wisdom, the use of additional spectral bands and a more sophisticated method not only required additional processing effort but also had a cost in terms of the accuracy and consistency of lake classifications.

  8. 75 FR 73983 - Proposed Modification of the Salt Lake City, UT, Class B Airspace Area; Public Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-30

    ... Federal Aviation Administration 14 CFR Part 71 Proposed Modification of the Salt Lake City, UT, Class B... information from airspace users and others concerning a proposal to revise the Class B airspace area at Salt... Terminal, 397 North 2370 West, Salt Lake City, UT 84116. (3) The meeting on Thursday, February 3,...

  9. Pennsylvanian fusulinids from the Beaverhead Mountains, Morrison Lake area, Beaverhead County, Montana

    SciTech Connect

    Verville, G.J. ); Sanderson, G.A.; Baesemann, J.F. ); Hampton, G.L. III )

    1990-04-01

    A fusulinid fauna consisting of Triticites spp., Kansanella aff. K. tenuis (Merchant Keroher), Eowaeringella sp., Fusulina sp. (Beedeina of some authors), Wedekindellina henbesti (Skinner), Plectofusulina spp., Pseudostaffella sp., Fusulinella aff. F. acuminata Thompson, and Eoschubertella sp. has been identified from Pennsylvanian rocks exposed on the Continental Divide, Morrison Lake area, Beaverhead County, Montana. These fusulinids, the first to be published from Pennsylvanian rocks in southwestern Montana, indicate that strata of late Atokan, early Desmoinesian, Missourian, and Virgilian age are present. These rocks, previously assigned to the Quadrant Formation in the Morrison Lake area, are subdivided and correlated with the Bloom, Gallagher Peak Sandstone and Juniper Gulch members of the Snaky Canyon Formation (Skipp et al., 1979a).

  10. A study of vital and health statistics of the Kainji Lake Area of Nigeria.

    PubMed

    Adekolu-John, E O

    1988-09-01

    A survey of vital and health statistics, and the evaluation of collection of these data in the registration centres of Kainji Lake Area, are presented. Forty-two per cent of all deaths occurred below 10 years of age, with the largest percentage occurring below 5 years of age. The leading causes of all deaths were malaria, gastro-intestinal disorders and measles. Occurrence of an epidemic was found to be significant to the overall mortality. The role of traditional healers in the control of childhood mortality is discussed. About 34% of the women had married more than once and 56% of the divorces occurred after the first marriage. The causes of divorces were largely due to loss of affection and neglect. The number of deliveries in the hospitals was more than the number of registered births and no death was registered at the centres. A unique system of collection of vital information was suggested for the Kainji Lake Area. PMID:2845754

  11. Bathymetric map, area/capacity table, and sediment volume estimate for Millwood Lake near Ashdown, Arkansas, 2013

    USGS Publications Warehouse

    Richards, Joseph M.; Green, W. Reed

    2013-01-01

    Millwood Lake, in southwestern Arkansas, was constructed and is operated by the U.S. Army Corps of Engineers (USACE) for flood-risk reduction, water supply, and recreation. The lake was completed in 1966 and it is likely that with time sedimentation has resulted in the reduction of storage capacity of the lake. The loss of storage capacity can cause less water to be available for water supply, and lessens the ability of the lake to mitigate flooding. Excessive sediment accumulation also can cause a reduction in aquatic habitat in some areas of the lake. Although many lakes operated by the USACE have periodic bathymetric and sediment surveys, none have been completed for Millwood Lake. In March 2013, the U.S. Geological Survey (USGS), in cooperation with the USACE, surveyed the bathymetry of Millwood Lake to prepare an updated bathymetric map and area/capacity table. The USGS also collected sediment thickness data in June 2013 to estimate the volume of sediment accumulated in the lake.

  12. Climatic data for the Cottonwood Lake area, Stutsman County, North Dakota, 1983

    USGS Publications Warehouse

    Sturrock, A.M.; Hanson, B.A.; Scarborough, J.L.; Winter, T.C.

    1987-01-01

    Research on the hydrology of the Cottonwood Lake area, Stutsman County, North Dakota, includes study of evaporation. Climatic data needed for energy-budget and mass-transfer evaporation studies that were collected during 1983 include water-surface temperature, sediment temperature, dry-bulb and wet-bulb air temperature, vapor pressure at and above the water surface, wind speed, and short-and long-wave radiation. Data are collected at raft and land stations. (USGS)

  13. Climatic data for the Cottonwood Lake area, Stutsman County, North Dakota 1982

    USGS Publications Warehouse

    Sturrock, A.M.; Hanson, B.A.; Scarborough, J.L.; Winter, T.C.

    1986-01-01

    Research on the hydrology of the Cottonwood Lake area, Stutsman County, North Dakota, includes study of evaporation. Presented here are those climatic data needed for energy-budget and mass-transfer evaporation studies, including: water-surface temperature, sediment temperature dry-bulb and wet-bulb air temperatures, vapor pressure at and above the water surface, wind speed, and short- and long-wave radiation. Data were collected at raft and land stations. (USGS)

  14. Biomass estimation of wetland vegetation in Poyang Lake area using ENVISAT advanced synthetic aperture radar data

    NASA Astrophysics Data System (ADS)

    Liao, Jingjuan; Shen, Guozhuang; Dong, Lei

    2013-01-01

    Biomass estimation of wetlands plays a role in understanding dynamic changes of the wetland ecosystem. Poyang Lake is the largest freshwater lake in China, with an area of about 3000 km2. The lake's wetland ecosystem has a significant impact on leveraging China's environmental change. Synthetic aperture radar (SAR) data are a good choice for biomass estimation during rainy and dry seasons in this region. In this paper, we discuss the neural network algorithms (NNAs) to retrieve wetland biomass using the alternating-polarization ENVISAT advanced synthetic aperture radar (ASAR) data. Two field measurements were carried out coinciding with the satellite overpasses through the hydrological cycle in April to November. A radiative transfer model of forest canopy, the Michigan Microwave Canopy Scattering (MIMICS) model, was modified to fit to herbaceous wetland ecosystems. With both ASAR and MIMICS simulations as input data, the NNA-estimated biomass was validated with ground-measured data. This study indicates the capability of NNA combined with a modified MIMICS model to retrieve wetland biomass from SAR imagery. Finally, the overall biomass of Poyang Lake wetland vegetation has been estimated. It reached a level of 1.09×109, 1.86×108, and 9.87×108 kg in April, July, and November 2007, respectively.

  15. Preliminary tephra-fall records from three lakes in the Anchorage, Alaska area: advances towards a regional tephrochronostratigraphic framework

    NASA Astrophysics Data System (ADS)

    Wallace, K. L.; Kaufman, D. S.; Schiff, C. J.; Kathan, K.; Werner, A.; Hancock, J.; Hagel, L. A.

    2010-12-01

    Sediment cores recovered from three kettle lakes, all within 10 km of Anchorage, Alaska contain a record of tephra fall from major eruptive events of Cook Inlet volcanoes during the past 11250 yr. Prominent tephra layers from multiple cores within each lake were first correlated within each basin using physical properties, major-oxide glass geochemistry, and constrained by bracketing radiocarbon age. Distinct tephra from each lake were then correlated among all three lakes using the same criteria to develop a composite tephrostratigraphic framework for the Anchorage area. Lorraine Lake, the northern-most lake contains 17 distinct tephra layers; Goose Lake, the eastern most lake contains 10 distinct tephra layers; and Little Campbell Lake, to the west, contains 7 distinct tephra layers. Thinner, less-prominent tephra layers, reflecting smaller or more distant eruptions, also occur but are not included as part of this study. Of the 33 tephra layers, only two could be confidently correlated among all three lakes, and four other correlative deposits were recognized in two of the three lakes. The minimum number of unique major tephra-fall events in the Anchorage area is 22 in the past 11200 years, or about 1 event every 500 years. This number underestimates the actual number of eruptions because not attempt was made to locate crypto-tephra. All but perhaps one tephra deposit originated from Cook Inlet volcanoes with the most prolific source being Mount Spurr/Crater Peak, which is accountable for at least 8 deposits. Combining radiocarbon ages to produce an independent age model for each lake is in progress and will aid in confirming correlations and assigning detailed modeled-tephra age and uncertainty to each tephra layer.

  16. Aspects of the bottom sediment of Lake Nakaumi and Honjo area ~ featuring with organic matter and the Sulfides ~

    NASA Astrophysics Data System (ADS)

    Shinohara, R.

    2015-12-01

    Lake Nakaumi is a brackish water located at southwest Japan. Seawater from the Sea of Japan inflows through Sakai-strait, and river water flows through the Oohashi River into this lake. Lake Nakaumi is characterized with hypoxic and/or anoxic condition of bottom water derived with the distinct stratification of salinity in summer season. In this lake, a public project had been carried out for land reclamation since 1963. Honjo Area located to the north part of Lake Nakaumi, was semi-separated from Lake Nakaumi by reclamation dikes constructed for this project at 1981. However, this public project was aborted with the change of social conditions. To the effective utilization of the area, the partial removal of dike was carried out. Seawater from Sakai-strait flows directly into Honjo Area again. Environmental change of the lake is expected by this inflow of the seawater in Lake Nakaumi and Honjo Area after this restoration. It is well known that the surface sediment reflects the environment of lake bottom. The organic matter and the sulfides in sediment are good indicators of sedimentation environment. In this study, we analyzed them by several methods and grasped the bottom environment of both areas after the removal of dikes. We examined the impact of the restoration to both areas by comparing the observations with the past data. Surface sediment samples in Lake Nakaumi and Honjo Area were obtained at 77 and 40 stations, respectively. We collected surface sediment (about 1cm) were for each station, and analyzed total organic carbon (TOC) and total nitrogen (TN) as organic matter, and hydrogen sulfide (H2S) in pore water, total sulfide (TS) and acid volatile sulfide (AVS) as sulfides. TOC contents of Lake Nakaumi and Honjo Area range within 0.0-5.1% and 0.2-4.9%, respectively. TN contents range within 0.0-0.6 % and 0.1-0.6 %. TS contents range within 0.1-2.6% and 0.0-2.0 %. H2S contents range within 0.3-119.0 ppm and 0.5-140.4 ppm. AVS contents range within 0

  17. The Geysers-Clear Lake area, California: thermal waters, mineralization, volcanism, and geothermal potential

    USGS Publications Warehouse

    Donnelly-Nolan, J. M.; Burns, M.G.; Goff, F.E.; Peters, E.K.; Thompson, J.M.

    1993-01-01

    Manifestations of a major thermal anomaly in the Geysers-Clear Lake area of northern California include the late Pliocene to Holocene Clear Lake Volcanics, The Geysers geothermal field, abundant thermal springs, and epithermal mercury and gold mineralization. The epithermal mineralization and thermal springs typically occur along high-angle faults within the broad San Andreas transform fault system that forms the western boundary of the North American plate in this area. The young volcanic rocks overlie Mesozoic marine rocks of the Great Valley sequence which have been thrust above the coeval Franciscan Complex and penecontemporaneously dropped back down along low-angle detachment faults. Geothermal power production has peaked at The Geysers and pressure declines indicate significant depletion of the fluid resource. It is proposed that recently discovered, isotopically shifted steam in the northwest Geysers area indicates the presence not of deep connate water but rather of boiled-down, boron-rich Franciscan evolved meteoric water. This water is likely to be present in limited quantities and will not provide a significant hot water resource for geothermal power production at The Geysers field or from the main Clear Lake volcanic field. -from Authors

  18. Perylene in Lake Biwa sediments originating from Cenococcum geophilum in its catchment area

    NASA Astrophysics Data System (ADS)

    Itoh, Nobuyasu; Sakagami, Nobuo; Torimura, Masaki; Watanabe, Makiko

    2012-10-01

    Perylene, which is composed of five benzene rings, is commonly found in sediments throughout the world at concentrations and distributions that are different from those of other polycyclic aromatic hydrocarbons. The only information available on the origin of perylene comes from 4,9-dihydroxyperylene-3,10-quinone (DHPQ), which originates from fungal component symbiosis or from parasites on plants; however, there is no direct evidence of a mechanism of perylene formation. In this study, we examined the relationship between sedimentary perylene and Cenococcum geophilum (C. geophilum) in a catchment area at Lake Biwa. Sclerotium grains of C. geophilum containing DHPQ were found in this catchment area (approximately 40 balls kg-1 dried soil for >1 mm-ϕ), and small sclerotium grains were frequently found in the sediment. In the sediment sample, we also found broken particles containing perylene, and they had a porous structure characteristic of sclerotium grains. Furthermore, the particles contained DHPQ in different transformation stages to perylene via 3,10-perylenequinone (3,10-PQ). This finding was consistent with results from elemental analysis (oxygen/carbon). Because a remarkable amount of DHPQ originating from C. geophilum also exists in the humic acids of soils and because the inputs of compounds to the lake depend strongly on the rivers, perylene in the Lake Biwa sediment originates mainly from the DHPQ of C. geophilum in its catchment area.

  19. Detecting changes in surface water area of Lake Kyoga sub-basin using remotely sensed imagery in a changing climate

    NASA Astrophysics Data System (ADS)

    Nsubuga, F. W. N.; Botai, Joel O.; Olwoch, Jane M.; Rautenbach, C. J. deW; Kalumba, Ahmed M.; Tsela, Philemon; Adeola, Abiodun M.; Sentongo, Ausi A.; Mearns, Kevin F.

    2015-09-01

    Detection of changes in Earth surface features, for example lakes, is important for understanding the relationships between human and natural phenomena in order to manage better the increasingly scarce natural resources. This work presents a procedure of using modified normalised difference water index (MNDWI) to detect fluctuations of lake surface water area and relate it to a changing climate. The study used radiometrically and geometrically rectified Landsat images for 1986, 1995 and 2010 encompassing the Kyoga Basin lakes of Uganda, in order to investigate the changes in surface water area between the respective years. The standard precipitation index (SPI) and drought severity index (DSI) are applied to show the relationship between variability of surface water area and climate parameters. The present analysis reveals that surface water area fluctuation is linked to rainfall variability. In particular, Lake Kyoga sub-basin lakes experienced an increase in surface water area in 2010 compared to 1986. This work has important implications to water resources management for Lake Kyoga and could be vital to water resource managers across Ugandan lakes.

  20. [Landscape pattern changes at village scale using high resolution satellite images: A case study in low-slope hilly area of Dali City, Northwestern Yunnan Province].

    PubMed

    Zhao, Ming-yue; Peng, Jian; Liu, Yan-xu; Zhang, Tian

    2015-12-01

    Human activity is the main driving force of the change of land cover and landscape patterns. However, there are few studies focusing on the mechanism of human-induced change of land cover and landscape patterns at village scale. In this study, taking low-slope hilly area of Dali City, Northwestern Yunnan Province as a case study area, high resolution satellite images were introduced to find out the rules of land cover and landscape pattern changes, i.e. GeoEye-1 of 2009 and World- View-3 of 2014. The object-oriented and human-computer-interaction approaches were applied to interpret the images using ArcGIS 10.2 and ENVI 5.2. The results showed that, the main land cover types in the study area were forest land, paddy field and dry land in 2009, with forest, bulldozed unbuilt ground and paddy field in 2014, accounting for 82.8% and 70.9% of the total area, respectively. The land cover transition showed that, during 2009-2014, the main land cover change flows were from forest land, paddy field and dry land, to bulldozed unbuilt ground and construction land. Furthermore, the area of bulldozed but unbuilt land had increased to be 531.57 hm² in 2014, which mainly came from forest land (42.8%), dry land (21.7%), and paddy field (14.2%). Landscape pattern change was characterized as the increase of patch quantity and density, the decrease of mean patch size, the complication of patch shape, the fragmentation of landscape patches, and the diversification of landscape patterns. PMID:27112022

  1. Canine echinococcosis in Turkana (north-western Kenya): a coproantigen survey in the previous hydatid-control area and an analysis of risk factors.

    PubMed

    Buishi, I; Njoroge, E; Zeyhle, E; Rogan, M T; Craig, P S

    2006-10-01

    A study of Echinococcus granulosus infection in dogs, with risk-factor analysis, was carried out in the endemic area of northern Turkana district, Kenya, using necropsy on 42 strays and a coproantigen-ELISA survey of 161 owned animals. During the post-mortem examinations, 14 (33%) of the necropsied dogs were found infected with E. granulosus, with a mean burden of 540 worms (range=two to 4080 worms). The 26 necropsied dogs that came from the north-western Lokichoggio division--an area where, from 1983 to 1997, there had been a continuous programme of hydatid control--showed a similar prevalence of infection to the other dogs (34.6%) but a significantly lower mean burden, of 53 worms (range=two to 300). Forty-two (26%) of the animals tested for Echinococcus coproantigen were found positive. Although the dogs from the Lokichoggio division were more likely to be coproantigen-positive (29%) than those from the central Kakuma division (20%) or the north-eastern division (18%), the differences were not statistically significant. In questionnaire-based interviews, the owners of the dogs tested for coproantigens were asked about possible risk factors for canine infection with E. granulosus. Women were found to have twice the level of contact with dogs as men. The results of a univariate analysis of the dog-owners' responses revealed six factors that appeared to be significantly associated with a coproantigen-positive dog: non-restraint of the dog (P<0.001); dog fed on raw offal (P<0.001); the improper disposal of slaughter offal (P<0.001); the dog-owner's lack of knowledge about the transmission of echinococcosis (P=0.001); the dog not receiving anthelmintic treatment (P=0.003); and dog age < or =5 years (P=0.01). The results of a multivariate analysis confirmed that lack of dog restraint, access to raw offal, and young age of the dog (< or =5 years) each significantly increased the risk of coproantigen positivity (P, 0.005). Dogs that scavenged from cooking pots, were

  2. 33 CFR 165.1301 - Puget Sound and Adjacent Waters in Northwestern Washington-Regulated Navigation Area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Sound Vessel Traffic Service (PSVTS) VHF-FM radio frequency for the area in which the vessel is... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Puget Sound and Adjacent Waters... Areas Thirteenth Coast Guard District § 165.1301 Puget Sound and Adjacent Waters in...

  3. A millennial-long record of warm season precipitation and flood frequency for the North-western Alps inferred from varved lake sediments: implications for the future

    NASA Astrophysics Data System (ADS)

    Amann, Benjamin; Szidat, Sönke; Grosjean, Martin

    2015-05-01

    The recent warming of the global climate is well recognized. However, does a warmer climate also mean a moister climate? Does dry get drier and wet get wetter? There are important questions as they relate to changes in the water cycle and impacts the water resources as well as the frequency and intensity of storms and floods in the near future. In Europe, regional climate models do not show consistent and robust results for future hydroclimatic changes and how extreme events will evolve in response to future climate change. Paleo-hydroclimatic data from natural archives are one of the few means to assess such changes in the longer context. Here, we present an annually-resolved record of warm season (MJJA) precipitation and summer flood frequency from the varved (annually laminated) sediments of proglacial Lake Oeschinen (46°30‧N-7°44‧E, 1580 m, NW Swiss Alps) back to AD 884. These data sets are inferred from the thickness of annual sediment deposits and the occurrence of flood event layers in the sediments. The chronology of the sediment record is based on multiple varve counts and validated with historical floods chronicled in written documents (back to the 14th century) and 14C AMS dates. The precipitation record shows pronounced interannual to centennial variability with humid warm season phases between AD 920-950, AD 1100-1180, AD 1300-1400, AD 1590-1650, AD 1700-1790, AD 1820-1880, and AD 1960-2008. Driest conditions are reconstructed for AD 960-1080, AD 1250-1300 and for AD 1880-1900. Our precipitation record is consistent with the few multi-centennial warm-season precipitation records available for Europe. We did not find a persistent relationship between warm-season precipitation and temperature. In contrast, results show that the relation between precipitation and temperature has oscillated between positive correlations (warmer gets wetter, cooler gets drier) and negative correlations (warmer gets drier, cooler gets wetter) with a highly significant

  4. Monitoring crustal deformation in The Geysers-Clear Lake geothermal area, California

    USGS Publications Warehouse

    Lofgren, Ben Elder

    1978-01-01

    Geodetic surveys since 1972-73 reveal significant crustal deformation in The Geysers-Clear Lake region. Resurveys of precise control networks are measuring both vertical and horizontal ground movement, with most of the change continuing in the area of geothermal fluid withdrawal. Preliminary evidence suggests right-lateral horizontal movement on northwest-trending fault systems and vertical and horizontal compression of the deep geothermal reservoir system. A direct correlation is suggested between ground-surface deformation and subsurface pressure changes in the reservoir system. Although surface changes appear too small to be of environmental concern in The Geysers-Clear Lake region, they indicate hydrodynamic changes in the reservoir of significant import. Two types of vertical changes in The Geysers production area are indicated in the 1973-77 data--(a) a regional subsidence between the Collayomi and Mercuryville fault zones and (b) local subsidence directly related to the area of principal steam production. Maximum subsidence of 13 centimeters in 4? years occurred in the area of most concentrated steam withdrawals and where fluid-pressure declines were near maximum. Subsidence rates throughout the production area from 1973 to 1975 were about half the 1975-77 rates in apparent correlation with pressure changes measured in the reservoir system. Horizontal ground movement as great as 2.0 centimeters per year, generally inward toward the center of production, was measured around the perimeter of the steam production area.

  5. The quagga mussel crisis at Lake Mead National Recreation Area, Nevada (U.S.A.).

    PubMed

    Hickey, Valerie

    2010-08-01

    Parks are cornerstones of conservation; and non-native invasive species drive extensive changes to biological diversity in parks. Knowing this, national park staff at Lake Mead National Recreation Area in the southwestern United States had a program in place for early detection of the non-native, invasive quagga mussel (Dreissena rostriformis bugensis). Upon finding the mussel in January 2007, managers moved quickly to access funding and the best available science to implement a response. Managers considered four options--doing nothing, closing the park, restricting movement on the lakes, and educating and enforcing park visitors--and decided to focus on education and enforcing existing laws. Nonetheless, quagga spread throughout the park and soon began to appear throughout the western United States. I examined why efforts to control the expansion failed and determined the general lessons to be learned from this case. Concentrating human visitation on the lakes through land-use zoning opened a pathway for invasion, reduced management options, and led to the rapid spread of quagga. To reconcile competing mandates to protect nature and provide recreation, zoning in parks has become a common practice worldwide. It reduces stress on some areas of a park by restricting and thus concentrating human activity in particular areas. Concentrating the human activity in one area does three things: cements pathways that repeatedly import and export vectors of non-native invasive species; creates the disturbed area necessary to enable non-native invasive species to gain a foothold; and, establishes a source of invasions that, without appropriate controls, can quickly spread to a park's wilderness areas. PMID:20337691

  6. Venezuela: Lake Maracaibo

    Atmospheric Science Data Center

    2013-04-18

    article title:  Oil Slicks on Lake Maracaibo, Venezuela     View Larger Image Several oil slicks occurred on Lake Maracaibo in northwestern Venezuela between ... wave facets divert reflected rays into many directions. An oil film dampens the presence of small wind-driven "capillary" waves, resulting ...

  7. CONFIRMATORY SURVEY REPORT FOR THE SECTION 4 AREA AT THE RIO ALGOM AMBROSIA LAKE FACILITY NEW MEXICO

    SciTech Connect

    W.C. Adams

    2010-02-12

    The objectives of the confirmatory survey were to verify that remedial actions were effective in meeting established release criteria and that documentation accurately and adequately described the final radiological conditions of the RAM Ambrosia Lake, Section 4 Areas.

  8. Morphology, distribution, and estimated eruption volumes for intracaldera tuffs associated with volcanic-hosted massive sulfide deposits in the Archean Sturgeon Lake Caldera Complex, Northwestern Ontario

    NASA Astrophysics Data System (ADS)

    Hudak, George J.; Morton, Ronald L.; Franklin, James M.; Peterson, Dean M.

    The Archean Sturgeon Lake Caldera Complex (SLCC) comprises a well-preserved, north-facing homoclinal sequence of greenschist facies metamorphosed intrusive, volcanic, and sedimentary strata. This piecemeal caldera complex is at least 25 km in strike length and contains nearly 3000 meters of dominantly subaqueously deposited intracaldera fill. Episodes of subaerial and subaqueous explosive felsic volcanism produced rhyodacitic to rhyolitic tuffs and lapilli tuffs. Progressing stratigraphically upward, the most voluminous are: a) the High Level Lake Tuff (˜16km3 b) the Mattabi Tuff (˜27km3) and c) the Middle L Tuff (˜7km3). The subaerially erupted, subaerially and locally subaqueously deposited High Level Lake Tuff comprises an 80-300 meter-thick unit composed of basal, poorly sorted, massive to normal graded, quartz-phyric, locally spherulitic tuffs and lapilli tuffs (30—150m thick) that are overlain by thin-bedded tuffs (<1-5m thick). The subaqueously erupted and deposited Mattabi Tuff contains up to thirteen individual flow units, each comprising two distinct depositional facies: a) lower, quartz-phyric, poorly sorted, ungraded, massive tuffs and lapilli tuffs (20-250 meters thick; and b) upper, laminated to medium bedded, typically normal graded tuffs (1-13 meters thick). The subaqueously erupted and deposited Middle L Tuff is also characterized by two distinct lithofacies: a) lower graded, quartz- and, rarely, potassium feldspar-phyric tuffs and lapilli tuffs (5-120m thick); and b) overlying, well-sorted, laminated to thickly bedded, normal graded tuffs (Lake, VHMS ore deposition appears to be favored by processes associated with the generation of voluminous subaqueous explosive eruptions.

  9. 1.4 kyrs of flash flood events in the Southern European Alps: implications for extreme precipitation patterns and forcing over the north-western Mediterranean area

    NASA Astrophysics Data System (ADS)

    Wilhelm, B.; Arnaud, F.; Sabatier, P.; Crouzet, C.; Brisset, E.; Guiter, F.; Reyss, J. L.; Chaumillon, E.; Tachikawa, K.; Bard, E.; Delannoy, J. J.

    2012-04-01

    Extreme precipitation events trigger flash floods causing large human and economic losses. Their frequency and/or intensity are expected to increase in the context of global warming, especially in the Mediterranean region. However, the relationship between such events and past climate change remains difficult to assess. Indeed, the stochastic nature of extreme event occurrence precludes the identification of trends. This is reinforced by a lack in long-term instrumental data. It is hence essential to reconstruct long-term geological records of intense events to extend documented records beyond the observational data. This will enable a better understanding of local to regional flood hazard patterns in the context of global warming and hence improve predictive models. In the framework of Pygmalion research program, a multiproxy investigation of the Lake Allos (2230 m a.s.l., Southern French Alps) sediment sequence revealed the presence of 160 flood-triggered interbedded layers within a 1400-long sequence. Owing to sedimentary and geochemical characteristics and the frequent occurrence, such deposits were interpreted as the result of high-energy sediment inputs during intense torrential floods (i.e. flash-floods), related to extreme precipitation events. Furthermore the significant relationship between the thickness and the basal grain size of the graded beds allowed using the thickness as a proxy of the flood intensity. Trough the comparison with local historic flood reconstructions over the last 400 years, we argue that these flash floods were mostly triggered by autumnal meso-scale intense precipitation events. Since the Medieval Climate Anomaly (MCA), the absence of major change in erosion processes and local vegetation dynamics linked to anthropogenic impact led us to interpret the Allos flood record as the proxy for the occurrence of such extreme precipitation events over the last millennium. The frequency of Allos flash-flood events appeared consistent with

  10. Lyme disease in northwestern coastal California.

    PubMed Central

    Ley, C; Davila, I H; Mayer, N M; Murray, R A; Rutherford, G W; Reingold, A L

    1994-01-01

    To determine the incidence of physician-diagnosed Lyme disease in an endemic area of California, an active surveillance program was implemented in Lake, Mendocino, Sonoma, and southern Humboldt counties. More than 200 medical care providers were called monthly for their list of suspected cases of Lyme disease. Pertinent information was abstracted from the medical record of each patient. Of 153 cases of possible early Lyme disease ascertained from July 1991 to December 1992, 37% consisted of physician-diagnosed erythema migrans. Only 58% of erythema migrans rashes were at least 5 cm in diameter. An additional 43 patients had suspicious rashes not classified as erythema migrans. Of 166 patients with possible late-stage Lyme disease, 31% had specific clinical symptoms and 75% had a positive serologic test. With an incident case defined as physician-diagnosed erythema migrans of at least 5 cm in diameter, the annual incidence of Lyme disease in northwestern coastal California according to active surveillance only was 5.5 per 100,000. The rate of Lyme disease in California is substantially lower than that in the Atlantic northeastern United States. Many suspected cases of Lyme disease in this endemic area do not meet surveillance criteria, which are intentionally restrictive. Although some of the illnesses not meeting surveillance criteria may be due to infection with Borrelia burgdorferi, it appears that Lyme disease is being overdiagnosed in this area. Images PMID:8053175

  11. Lake Urmia Shrinkage and its Effect on the Settlement of the Surrounding Areas Investigated Using Radar and Optical Satellite Images

    NASA Astrophysics Data System (ADS)

    Motagh, M.; Shamshiri, R.; Hosseini, F.; Sharifi, M. A.; Baes, M.

    2014-12-01

    With a total area of more than 50000 km^2 Lake Urmia basin in northwest of Iran was once one of the biggest salt lakes in the world. The lake has been shrinking in the recent years, losing in turn dramatically its area. A lot of factors have been attributed to this shrinking including construction of dams on the rivers feeding the lake and overexploitation of groundwater for agricultural and industrial purposes. In this study we first utilized time-series analysis of Landsat images to precisely quantify surface changes in the region between 1984 and 2013. We then analyzed a number of SAR images from 2002 to 2014 including 30 ASAR images from Envisat, 10 PALSAR images from ALOS, and more than 35 TerraSAR-X (TSX) in both Stripmap and Spot modes to assess surface ground deformation. Ground deformation was evaluated for both agricultural regions around the lake and Lake Urmia Causeway (LUC), connecting two provinces of East and West Azerbaijan on both sides of the lake. The InSAR results of the LUC embankments is further investigated using Finite Element approach to better understand the relation between soil parameters, lake level changes and settlement of the LUC. The classification results using optical imagery analysis show that human and anthropogenic activities have resulted in shrinking of Lake Urmia by more than 60% over the past 30 years. The agricultural areas around the lake are dominated by ground subsidence reaching to 10 cm/yr in places. The LUC embankments also show large deformation with peak settlement of more than 5 cm/yr over the last decade. FEM simulation shows that consolidation due to dissipation of excess pore pressure in embankments can satisfactorily explain its surface deformation.

  12. Revision of the genus Pseudapanteles (Hymenoptera, Braconidae, Microgastrinae), with emphasis on the species in Area de Conservación Guanacaste, northwestern Costa Rica

    PubMed Central

    Fernández-Triana, Jose L.; Janzen, Daniel H.; Hallwachs, Winnie; Whitfield, James B.; Smith, M. Alex; Kula, Robert

    2014-01-01

    Abstract Pseudapanteles is a moderately diverse genus of Microgastrinae parasitoid wasps (Hymenoptera: Braconidae), endemic to the New World and with the vast majority of its species (including many undescribed) in the Neotropical region. We describe here 25 new species from Area de Conservación Guanacaste (ACG), northwestern Costa Rica, based on 400 studied specimens. A key to all 36 known species of Pseudapanteles is provided (except for Pseudapanteles brunneus, only known from a single male), and species are placed in three newly created species-groups. Host records are known for only 25% of the species; most are solitary parasitoids of the caterpillars of several families of small Lepidoptera (Crambidae, Elachistidae, Gelechiidae, Incurvariidae, Sesiidae, Tineidae). DNA barcodes (part of the CO1 gene) were obtained for 30 species (83%), and provide a start for future study of the genus beyond ACG. Brief descriptions (generated by Lucid 3.5 software) and extensive illustrations are provided for all species. The following new taxonomic and nomenclatural acts are proposed: Pseudapanteles moerens (Nixon, 1965), comb. n., Pseudapanteles brunneus Ashmead, 1900, comb. rev., a lectotype is designated for Pseudapanteles ruficollis (Cameron, 1911), and the following 25 species nova of Pseudapanteles (all authored by Fernández-Triana and Whitfield): alfiopivai, alvaroumanai, analorenaguevarae, carlosespinachi, carlosrodriguezi, christianafigueresae, hernanbravoi, jorgerodriguezi, josefigueresi, laurachinchillae, luisguillermosolisi, margaritapenonae, mariobozai, mariocarvajali, maureenballesteroae, munifigueresae, oscarariasi, ottonsolisi, pedroleoni, raulsolorzanoi, renecastroi, rodrigogamezi, rosemarykarpinskiae, soniapicadoae, teofilodelatorrei. PMID:25349512

  13. Ecological restoration and soil improvement performance of the seabuckthorn flexible dam in the Pisha Sandstone area of Northwestern China

    NASA Astrophysics Data System (ADS)

    Yang, F. S.; Cao, M. M.; Li, H. E.; Wang, X. H.; Bi, C. F.

    2014-09-01

    Soil erosion of the Pisha Sandstone area of Loess Plateau is extremely severe in China. The Pisha Sandstone is very hard when it is dry, while it is very frail when wet. The seabuckthorn flexible dam (SFD), a type of ecological engineering, was proposed to control soil erosion and meliorate soil within the Pisha Sandstone area. To assess its effectiveness and the ecological restoration and soil improvement performance, a field experiment was conducted in this area. We found the strong sediment retention capacity of the SFD is the basis of using it to restore the ecosystem. We compared some certain ecological factors and soil quality between a gully with the SFD and a gully without the SFD, including soil moisture, soil organic matter (SOM), soil nutrients (including Ammonia Nitrogen, available phosphorus and Potassium), vegetation coverage and biodiversity. The results showed that the SFD exhibits excellent performance for ecological restoration and soil improvement of this area. The results are as follows: (i) by the sediment retention action, the deposition commonly occurred in the SFD gully, and the deposition patterns are obviously different from upper to lower gully, (ii) more surprisingly, unlike trees or other shrubs, the seabuckthorn has good horizontal extending capacity by its root system, (iii) soil moisture, SOM, soil nutrients, vegetation coverage and biodiversity in the vegetated gully with the SFD are all markedly increased. The results showed the SFD is both effective and novel biological measure for ecological restoration and soil improvement within the Pisha Sandstone area.

  14. The influence of the maintenance of terraced areas on slope stability during the November 2014 flood event in Liguria (northwestern Italy)

    NASA Astrophysics Data System (ADS)

    Giordan, Daniele; Poggi, Flavio; Baldo, Marco; Cignetti, Martina

    2016-04-01

    Terraced environments are a widespread feature of the coastal settlement of eastern Liguria (northwestern Italy) and they constitute a well-known favorable role in slope stability. In this region, starting from the twentieth century, the progressive abandonment of agriculture determines a progressively increasing lack of maintenance of the terraces, consequently raising the level of slope instability. Moreover, it should be taken into account not only the level of terraces maintenance, but also their interaction with several factors as i) geological and geomorphological conditions, ii) soil properties, iii) hydrological and hydrogeological conditions, and iv) land use, causing an increase in landslides occurrence. The definition of managed terraces effects on slope stability and their response to external stress like a flood event is rather complicated; a possible approach is a statistical analysis of the effects of a flood event over a large terraced area, distinguishing the maintained sectors from the abandoned ones. After the November 2014 flood event, which affected several sectors of the Liguria region, where a high number of shallow landslides were triggered, an airborne LiDAR survey of the damaged area was carried out. In particular, a high resolution Digital Terrain Model (DTM) resampled to a lower density (1 square meter grid spacing) and a photogrammetric coverage of the area was performed, in order to create a landslide map of the flood event. The surveyed area covered more than 380 square kilometers, and over 1600 shallow landslides triggered by the flood event were identified and inventoried. The high resolution DTM allowed the identification of terraced areas also in wooded sectors and a sharp mapping of the extension of terraced slopes in this portion of Liguria region. By considering: i) the terraced areas recognized through DTM analysis, ii) the mapped landslides, and iii) the land use classification, a correlation between the presence of terraces

  15. Assessing Seasonal and Inter-Annual Variations of Lake Surface Areas in Mongolia during 2000-2011 Using Minimum Composite MODIS NDVI.

    PubMed

    Kang, Sinkyu; Hong, Suk Young

    2016-01-01

    A minimum composite method was applied to produce a 15-day interval normalized difference vegetation index (NDVI) dataset from Moderate Resolution Imaging Spectroradiometer (MODIS) daily 250 m reflectance in the red and near-infrared bands. This dataset was applied to determine lake surface areas in Mongolia. A total of 73 lakes greater than 6.25 km2in area were selected, and 28 of these lakes were used to evaluate detection errors. The minimum composite NDVI showed a better detection performance on lake water pixels than did the official MODIS 16-day 250 m NDVI based on a maximum composite method. The overall lake area detection performance based on the 15-day minimum composite NDVI showed -2.5% error relative to the Landsat-derived lake area for the 28 evaluated lakes. The errors increased with increases in the perimeter-to-area ratio but decreased with lake size over 10 km(2). The lake area decreased by -9.3% at an annual rate of -53.7 km(2) yr(-1) during 2000 to 2011 for the 73 lakes. However, considerable spatial variations, such as slight-to-moderate lake area reductions in semi-arid regions and rapid lake area reductions in arid regions, were also detected. This study demonstrated applicability of MODIS 250 m reflectance data for biweekly monitoring of lake area change and diagnosed considerable lake area reduction and its spatial variability in arid and semi-arid regions of Mongolia. Future studies are required for explaining reasons of lake area changes and their spatial variability. PMID:27007233

  16. Assessing Seasonal and Inter-Annual Variations of Lake Surface Areas in Mongolia during 2000-2011 Using Minimum Composite MODIS NDVI

    PubMed Central

    Kang, Sinkyu; Hong, Suk Young

    2016-01-01

    A minimum composite method was applied to produce a 15-day interval normalized difference vegetation index (NDVI) dataset from Moderate Resolution Imaging Spectroradiometer (MODIS) daily 250 m reflectance in the red and near-infrared bands. This dataset was applied to determine lake surface areas in Mongolia. A total of 73 lakes greater than 6.25 km2in area were selected, and 28 of these lakes were used to evaluate detection errors. The minimum composite NDVI showed a better detection performance on lake water pixels than did the official MODIS 16-day 250 m NDVI based on a maximum composite method. The overall lake area detection performance based on the 15-day minimum composite NDVI showed -2.5% error relative to the Landsat-derived lake area for the 28 evaluated lakes. The errors increased with increases in the perimeter-to-area ratio but decreased with lake size over 10 km2. The lake area decreased by -9.3% at an annual rate of -53.7 km2 yr-1 during 2000 to 2011 for the 73 lakes. However, considerable spatial variations, such as slight-to-moderate lake area reductions in semi-arid regions and rapid lake area reductions in arid regions, were also detected. This study demonstrated applicability of MODIS 250 m reflectance data for biweekly monitoring of lake area change and diagnosed considerable lake area reduction and its spatial variability in arid and semi-arid regions of Mongolia. Future studies are required for explaining reasons of lake area changes and their spatial variability. PMID:27007233

  17. Hot dry rock resources of the Clear Lake Area, Northern California

    SciTech Connect

    Burns, K.L.

    1994-10-01

    The Geysers-Clear Lake geothermal area of northern California is underlain by an asthenospheric upwarp. The upwarp was generated at a slabless window trailing the northward-moving Mendocino triple junction. The geothermal area lies immediately east of the Rodgers Creek rather than the San Andreas fault because of a transform jump in progress. Decompression melting of the mantle has led to basaltic underplating, and crustal anatexis. The high heat flow is due to conduction through a thin lithosphere and the latent heat of solidifying basalt, while the uniformity is due to the distribution of sources over a wide area of large flatlying sills, The Hot Dry Rock resource has heat flow exceeding 4 HFU over an area exceeding 800 km2.

  18. Lake Storage Measurements For Water Resources Management: Combining Remotely Sensed Water Levels and Surface Areas

    NASA Astrophysics Data System (ADS)

    Brakenridge, G. R.; Birkett, C. M.

    2013-12-01

    Presently operating satellite-based radar altimeters have the ability to monitor variations in surface water height for large lakes and reservoirs, and future sensors will expand observational capabilities to many smaller water bodies. Such remote sensing provides objective, independent information where in situ data are lacking or access is restricted. A USDA/NASA (http://www.pecad.fas.usda.gov/cropexplorer/global_reservoir/) program is performing operational altimetric monitoring of the largest lakes and reservoirs around the world using data from the NASA/CNES, NRL, and ESA missions. Public lake-level products from the Global Reservoir and Lake Monitor (GRLM) are a combination of archived and near real time information. The USDA/FAS utilizes the products for assessing international irrigation potential and for crop production estimates; other end-users study climate trends, observe anthropogenic effects, and/or are are involved in other water resources management and regional water security issues. At the same time, the Dartmouth Flood Observatory (http://floodobservatory.colorado.edu/), its NASA GSFC partners (http://oas.gsfc.nasa.gov/floodmap/home.html), and associated MODIS data and automated processing algorithms are providing public access to a growing GIS record of the Earth's changing surface water extent, including changes related to floods and droughts. The Observatory's web site also provide both archival and near real time information, and is based mainly on the highest spatial resolution (250 m) MODIS bands. Therefore, it is now possible to provide on an international basis reservoir and lake storage change measurements entirely from remote sensing, on a frequently updating basis. The volume change values are based on standard numerical procedures used for many decades for analysis of coeval lake area and height data. We provide first results of this combination, including prototype displays for public access and data retrieval of water storage

  19. Geology and ground water of the Red Lake area, Navajo Indian Reservation, Arizona and New Mexico

    USGS Publications Warehouse

    Akers, J.P.; McClymonds, N.E.; Harshbarger, John William

    1962-01-01

    The Red Lake area in the Navajo Indian Reservation, Arizona and New Mexico, was studied by the U.S. Geological Survey to determine if 1 mgd (mil- lion gallons per day) of water could be obtained for the requirements of a proposed sawmill. Geologic mapping and stratigraphic studies indicated three favorable areas where ground water may be developed. Test holes were drilled under contract in the areas, and pumping tests indicate that 500,000 gpd (gal- lons per day) is available from alluvium along Tohdildonih Wash near Frog Rock, 100,000 gpd is available from the Shinarump member of the Chinle forma- tion and the De Chelly sandstone near Red Lake, and 800,000 gpd is available from alluvium and cinder beds in lapiUi tuff in Buell Park, an eroded diatreme. The diatreme at Buell Park is about 2% miles in diameter. It was formed by several explosions in which lapilli tuff and cinders were erupted. These materials, together with later basaltic intrusive and extrusive rock, now fill the diatreme. The tuff and cinders are water bearing, 'and they receive re- charge from rainwater and snowmelt moving through overlying alluvium and from storage in the De Chelly sandstone which encloses the east half of the diatreme. The quality of water from all areas is suitable for domestic use. However, special treatment may be necessary to make the water suitable for pulp processing.

  20. Reconnaissance investigation of the Lisburne Group in the Cobblestone Creek area, Chandler Lake quadrangle, Alaska

    USGS Publications Warehouse

    Dumoulin, Julie A.; Whalen, Michael T.

    2015-01-01

    A reconnaissance investigation of the Carboniferous Lisburne Group in the Cobblestone Creek area, Chandler Lake Quadrangle, yields insights into its resource potential and regional relations. Locally porous vuggy dolostone with hydrocarbon reservoir potential occurs in the lower Lisburne in the three most southerly of five thrust sheets, and contains traces of dead oil in two of these sheets. The dolostones are coarse crystalline, commonly cross-bedded, and at least in part of Osagean (late Early Mississippian) age; they have pelmatozoan grainstone protoliths that likely formed in sand shoals of the midramp to inner ramp. Similar, coeval porous dolostones occur in the Lisburne from Skimo Creek to Itkillik Lake, ~70 km west and 10 km east of the Cobblestone Creek area, respectively. We also examined the uppermost Lisburne Group at several localities in the Cobblestone Creek area, mainly in the northernmost thrust sheet where the rocks are as young as Morrowan (Early Pennsylvanian). Cobblestone sections contain more supportstone than equivalent strata at Skimo Creek, and overlying Permian successions also differ between the two areas. These lithologic contrasts may reflect different rates of tectonically controlled subsidence, and (or) changes in sediment input, along the late Paleozoic continental margin.

  1. Hydrogeologic and hydrogeochemical assessment of geothermal fluids in the Pyramid Lake area, Washoe country, Nevada

    SciTech Connect

    Ojiambo, S. Bwire

    1992-01-01

    This paper evaluates the hydrogeological and hydrogeochemical characteristics of the geothermal fluids in the Pyramid Lake area using data from existing published and unpublished reports on springs, challow and deep wells in the area. Four geochemical provinces, namely, chloride, bicarbonate, suphate and nixed chloride-bicarbonate have been identified. Chloride waters are found in known geothermal areas. Two subsurface water recharge zones which reed the shallow and deep geothermal systems are proposed. These are the Virginia Mountains and their Northern extension and the Fox and Lake Ranges. Tertiary and Quaternary faulting systems in these mountains and Ranges act as heat conduits for geothermal fluids. The Needle Rocks geothermal system is postulated to be deeper than the San Emidio system. A connection between the Needle Rocks system and the Pyramid and Anaho islands warm springs is not clear from this study because of lack of chemical data from these islands. More systematic measurements of static water levels, temperatures, well lithology, water chemistry and isotopes data are recommended to enable better understanding of the geothermal systems in the area.

  2. Relation of lower morrow sandstone and porosity trends to chester paleogeomorphology, Persimmon Creek field area, Northwestern Oklahoma

    SciTech Connect

    Webster, R.E.

    1983-11-01

    Thickness and porosity trends of several lower Morrow sandstone units were strongly influenced by the paleogeomorphology of the subjacent Mississippian Chester limestone in a study area near Persimmon Creek field in T20N, R22W, southwestern Woodward County, Oklahoma. PrePennsylvanian streams flowing south-southwest across the Anadarko basin shelf had created a dendritic drainage pattern with paleogradients of about 40 ft/mi(7.5 m/km), and intervening stream divides were 50 to 100 ft (15 to 30 m) above the valley floors. As the sea transgressed the area in the Early Pennsylvanian, cyclic transgressions and regressions led to deposition of four prominent lower Morrow sandstone members separated by shale units which are approximately parallel lithologic time markers.

  3. Applying the ecosystem approach to select priority areas for forest landscape restoration in the Yungas, Northwestern Argentina.

    PubMed

    Ianni, Elena; Geneletti, Davide

    2010-11-01

    This paper proposes a method to select forest restoration priority areas consistently with the key principles of the Ecosystem Approach (EA) and the Forest Landscape Restoration (FLR) framework. The methodology is based on the principles shared by the two approaches: acting at ecosystem scale, involving stakeholders, and evaluating alternatives. It proposes the involvement of social actors which have a stake in forest management through multicriteria analysis sessions aimed at identifying the most suitable forest restoration intervention. The method was applied to a study area in the native forests of Northern Argentina (the Yungas). Stakeholders were asked to identify alternative restoration actions, i.e. potential areas implementing FLR. Ten alternative fincas-estates derived from the Spanish land tenure system-differing in relation to ownership, management, land use, land tenure, and size were evaluated. Twenty criteria were selected and classified into four groups: biophysical, social, economic and political. Finca Ledesma was the closest to the economic, social, environmental and political goals, according to the values and views of the actors involved in the decision. This study represented the first attempt to apply EA principles to forest restoration at landscape scale in the Yungas region. The benefits obtained by the application of the method were twofold: on one hand, researchers and local actors were forced to conceive the Yungas as a complex net of rights rather than as a sum of personal interests. On the other hand, the participatory multicriteria approach provided a structured process for collective decision-making in an area where it has never been implemented. PMID:20814677

  4. Applying the Ecosystem Approach to Select Priority Areas for Forest Landscape Restoration in the Yungas, Northwestern Argentina

    NASA Astrophysics Data System (ADS)

    Ianni, Elena; Geneletti, Davide

    2010-11-01

    This paper proposes a method to select forest restoration priority areas consistently with the key principles of the Ecosystem Approach (EA) and the Forest Landscape Restoration (FLR) framework. The methodology is based on the principles shared by the two approaches: acting at ecosystem scale, involving stakeholders, and evaluating alternatives. It proposes the involvement of social actors which have a stake in forest management through multicriteria analysis sessions aimed at identifying the most suitable forest restoration intervention. The method was applied to a study area in the native forests of Northern Argentina (the Yungas). Stakeholders were asked to identify alternative restoration actions, i.e. potential areas implementing FLR. Ten alternative fincas—estates derived from the Spanish land tenure system—differing in relation to ownership, management, land use, land tenure, and size were evaluated. Twenty criteria were selected and classified into four groups: biophysical, social, economic and political. Finca Ledesma was the closest to the economic, social, environmental and political goals, according to the values and views of the actors involved in the decision. This study represented the first attempt to apply EA principles to forest restoration at landscape scale in the Yungas region. The benefits obtained by the application of the method were twofold: on one hand, researchers and local actors were forced to conceive the Yungas as a complex net of rights rather than as a sum of personal interests. On the other hand, the participatory multicriteria approach provided a structured process for collective decision-making in an area where it has never been implemented.

  5. Visual observations of historical lake trout spawning grounds in western Lake Huron

    USGS Publications Warehouse

    Nester, Robert T.; Poe, Thomas P.

    1987-01-01

    Direct underwater video observations were made of the bottom substrates at 12 spawning grounds formerly used by lake trout Salvelinus namaycush in western Lake Huron to evaluate their present suitability for successful reproduction by lake trout. Nine locations examined north of Saginaw Bay in the northwestern end of the lake are thought to provide the best spawning habitat. The substrate at these sites consisted of angular rough cobble and rubble with relatively deep interstitial spaces (a?Y 0.5 m), small amounts of fine sediments, and little or no periphytic growth. Conditions at the three other sampling locations south of Saginaw Bay seemed much less suitable for successful reproduction based on the reduced area of high-quality substrate, shallow interstitial spaces, high infiltration of fine sediments, and greater periphytic growth.

  6. Discharge and nutrient transport between lakes in a hydrologically complex area of Voyageurs National Park, Minnesota, 2010-2012

    USGS Publications Warehouse

    Christensen, Victoria G.; Wakeman, Eric; Maki, Ryan P.

    2016-01-01

    An acoustic Doppler velocity meter (ADVM) was deployed in the narrows between Namakan and Kabetogama Lakes in Voyageurs National Park, Minnesota, from November 3, 2010, through October 3, 2012. The ADVM can account for wind, seiche, and changing flow direction in hydrologically complex areas. The objectives were to (1) estimate discharge and document the direction of water flow, (2) assess whether specific conductance can be used to determine flow direction, and (3) document nutrient and chlorophyll a concentrations at the narrows. The discharge direction through the narrows was seasonal. Water generally flowed out of Kabetogama Lake and into Namakan Lake throughout the ice-covered season. During spring, water flow was generally from Namakan Lake to Kabetogama Lake. During the summer and fall, the water flowed in both directions, affected in part by wind. Water flowed into Namakan Lake 70% of water year 2011 and 56% of water year 2012. Nutrient and chlorophyll a concentrations were highest during the summer months when water-flow direction was unpredictable. The use of an ADVM was effective for assessing flow direction and provided flow direction under ice. The results indicated the eutrophic Kabetogama Lake may have a negative effect on the more pristine Namakan Lake. The results also provide data on the effects of the current water-level management plan and may help determine if adjustments are necessary to help protect the aquatic ecosystem of Voyageurs National Park.

  7. Drought-Caused Forest Decline In The Trans-Baikal Lake Area

    NASA Astrophysics Data System (ADS)

    Ranson, J.; Kharuk, V.; Oscorbin, P.; Im, S.

    2011-12-01

    One of the important consequences of observed and predicted climate change is regional desertification and conversion of forest lands into steppes. We documented progressive forest decline in the trans-Baikal Lake mountains (center point coordinates ~ 51°30'N/116°30'E). This area has a sever continental climate and is a transition area between the Siberian taiga and Mongolian steppes and deserts. Forests are dominated by birch and occupy north-facing mountains slopes (with elevations up to 1200 m). Southern facing slopes are typically covered by grass communities. Analysis of field measurements and satellite temporal data showed an increasing forest decline during the last decades (i.e, 1990-2010). The typical pattern of forest decline was ring-like with the forest die-back starting in the boundary area around the outside of the stand within the forest-grass transition zone. This decline was likely, caused by decreases in precipitation and soil water content. During the last two decades summer precipitation decrease was > 10% (P>0.05), and is now 270 ±30 mm/yr. Similarly, hydrothermal index value decreased to about 12% (P>0.05). Satellite-derived forest decline correlates with precipitation and hydrothermal index decreases. Soil studies showed highest water content values within soils of healthy stands, with minimum values within the dead stand areas, and intermediate within the transition zone. Satellite - based estimates of the total area with drought-caused forest decline was about 106 ha. Along with the observed decline of birch stands, two others climate-caused phenomena were noted within the study and adjacent areas during the last decades: a significant increase of fire frequency and decrease of lake surface area.

  8. Mineral resources of the Henry's Lake Wilderness Study Area, Fremont County, Idaho

    SciTech Connect

    Tysdal, R.G.; Kulik, D.M.; Peters, T.J.

    1988-06-10

    A mineral-resource survey of the 350-acre Henry's Lake Wilderness Study Area (ID-035-077) was made in 1986-87. No identified resources (known) or currently active claims exist within or adjacent to the wilderness study area. There is potential for several types of undiscovered mineral resources within the study area. The southwestern part of the wilderness study area, along the Madison Range fault, is rated as having a moderate energy-resource potential for geothermal water; the remainder of the study area has a low potential for resources of this commodity. A small outcrop of marble in the southernmost part of the study area has a low mineral-resource potential for talc; for talc in marble possibly concealed beneath the study area the mineral-resource potential is rated as unknown. The study area has a low mineral-resource potential for iron in hematite-mineralized amphibolite gneiss, and for gold, silver, and uranium. The area has no mineral-resource potential for phosphate, because the host strata have been eroded; and no resource potential for oil and gas.

  9. Quality of extra virgin olive oils produced in an emerging olive growing area in north-western Spain.

    PubMed

    Reboredo-Rodríguez, P; González-Barreiro, C; Cancho-Grande, B; Simal-Gándara, J

    2014-12-01

    Systematic studies of physico-chemical and stability-related properties, and chemical composition, of extra virgin olive oils (EVOOs) obtained from drupes cropped in specific regions are of special agricultural interest. This is particularly so with new production areas, where careful selection of the most suitable olive varieties for EVOO production is required. This paper reports the first comprehensive chemical characterisation of EVOOs obtained from three different olive varieties (viz., Picual, Morisca and Manzanilla de Sevilla) grown in a new cultivation area in Galicia (NW Spain). The Morisca variety was that providing the highest industrial oil yield (21%). However, the three types of EVOO exhibited no statistically significant differences in standard quality-related indices other than acidity. Morisca EVOO was that with the lowest content in oleic acid (mean=68%) and highest content in linoleic acid (mean=13%). Also, Morisca EVOO exhibited the highest sterol levels (mean=1,616 mg/kg) and Picual EVOO the lowest (mean=1,160 mg/kg). Picual EVOO contained greater amounts of the phenolic compounds luteolin and pinoresinol than both Morisca and Manzanilla de Sevilla EVOOs. Finally, Manzanilla de Sevilla EVOO exhibited differential attributes, with banana and olive fruit aromatic series prevailing predominantly over bitter-like, pungent-like and leaf series. PMID:24996353

  10. Habitat selection by juvenile Swainson’s thrushes (Catharus ustulatus) in headwater riparian areas, northwestern Oregon, USA

    USGS Publications Warehouse

    Jenkins, Stephanie R.; Betts, Matthew G.; Huso, Manuela M.; Hagar, Joan C.

    2013-01-01

    Lower order, non-fish-bearing streams, often termed “headwater streams”, have received minimal research effort and protection priority, especially in mesic forests where distinction between riparian and upland vegetation can be subtle. Though it is generally thought that breeding bird abundance is higher in riparian zones, little is known about species distributions when birds are in their juvenile stage – a critical period in terms of population viability. Using radio telemetry, we examined factors affecting habitat selection by juvenile Swainson’s thrushes during the post-breeding period in headwater basins in the Coast Range of Oregon, USA. We tested models containing variables expected to influence the amount of food and cover (i.e., deciduous cover, coarse wood volume, and proximity to stream) as well as models containing variables that are frequently measured and manipulated in forest management (i.e., deciduous and coniferous trees separated into size classes). Juvenile Swainson’s thrushes were more likely to select locations with at least 25% cover of deciduous, mid-story vegetation and more than 2.0 m3/ha of coarse wood within 40 m of headwater streams. We conclude that despite their small and intermittent nature, headwater streams and adjacent riparian areas are selected over upland areas by Swainson’s thrush during the postfledging period in the Oregon Coast Range.

  11. Primary studies of trace quantities of green vegetation in Mono Lake area using 1990 AVIRIS data

    NASA Technical Reports Server (NTRS)

    Chen, Zhi-Kang; Elvidge, Chris D.; Groeneveld, David P.

    1992-01-01

    Our primary results in Jasper Ridge Biological Preserve indicate that high spectral resolution Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data may provide a substantial advantage in vegetation, based on the chlorophyll red edge feature from 700-780 nm. The chlorophyll red edge was detected for green vegetation cover as low as 4.8 percent. The objective of our studies in Mono Lake area is to continue the experiments performed in Jasper Ridge and to examine the persistence of red edge feature of trace quantities of green vegetation for different plant communities with non-uniform soil backgrounds.

  12. Abnormal P-wave delays in the geysers-clear lake Geothermal Area, California

    USGS Publications Warehouse

    Iyer, H.M.; Oppenheimer, D.H.; Hitchcock, T.

    1979-01-01

    Large teleseismic delays, exceeding 1 second, are found near Mount Hannah in the Clear Lake volcanic field and in the steam-production area at The Geysers. The delays are superimposed on a general delay field of about 0.5 second extending over the volcanic rocks and the steam reservoir. It is postulated that a magma chamber under the surface volcanic rocks with a core of severely molten rock beneath Mount Hannah and a highly fractured steam reservoir probably underlain by partially molten rock at The Geysers are responsible for the observed delays. Both zones extend to depths of 20 kilometers or more. Copyright ?? 1979 AAAS.

  13. Digital models of a glacial outwash aquifer in the Pearl-Sallie Lakes area, west-central Minnesota

    USGS Publications Warehouse

    Larson, S.P.; McBride, Mark S.; Wolf, R.J.

    1975-01-01

    -p^e need for study of lake-ground-water interchange has been accentuated by eutrophication of lakes in the Pearl-Sallie Lakes area of west-central Minnesota. The local ground-water flow system is dominated by an outwash aquifer that is sandwiched between two till layers in the western part of the area and exposed at the land surface in the eastern part. Ground water discharges from the aquifer into lakes in the outwash area but is recharged from lakes in the till-covered area. Irregular aquifer geometry resulted in a complex ground-water flow system. Simulation of the system by areal and vertical-section models showed that the lakes significantly control groundwater flow near their boundaries. Inadequate field data and complex geology caused difficulty in obtaining solutions with the vertical-section model. The models may be used to guide collection and interpretation of field data, and quantification of the ground-water flow system. With modification, they could be used to predict aquifer response to transient stresses. They also could be incorporated into more complex models to determine the movement of solutes in the ground-water system.

  14. Mineral and geothermal resource potential of Wild Cattle Mountain and Heart Lake roadless areas Plumas, Shasta, and Tehama Counties, California

    SciTech Connect

    Muffler, L.J.P.; Clynne, M.A.; Cook, A.L.

    1982-01-01

    The results of geological, geochemical, and geophysical surveys in Wild Cattle Mountain and Heart Lake Roadless Areas indicate no potential for metallic or non-metallic mineral resources in the areas and no potential for coal or petroleum energy resources. However, Wild Cattle Mountain Roadless Area and part of Heart Lake Roadless Area lie in Lassen Known Geothermal Resources Area, and much of the rest of Heart Lake Roadless Area is subject to non-competitive geothermal lease applications. Both areas are adjacent to Lassen Volcanic National Park, which contains extensive areas of fumaroles, hot springs, and hydrothermally altered rock; voluminous silicic volcanism occurred here during late Pleistocene and Holocene time. Geochemical data and geological interpretation indicate that the thermal manifestations in the Park and at Morgan and Growler Hot Springs (immediately west of Wild Cattle Mountain Roadless Area) are part of the same large geothermal system. Consequently, substantial geothermal resources are likely to be discovered in Wild Cattle Mountain Roadless Area and cannot be ruled out for Heart Lake Roadless Area.

  15. Soil occupation and atmospheric variations over Sobradinho Lake area. Part two: a regional modeling study

    NASA Astrophysics Data System (ADS)

    Correia, M. F.; da Silva Dias, M. A. F.; da Silva Aragão, M. R.

    2006-11-01

    The impact of the changes on soil cover and land use brought about by the construction of the Sobradinho Dam in the semi-arid region of the São Francisco River Hydrographic Basin is analyzed by means of a numerical model RAMS. Disregarding the influence of a large scale flow, a set of factors were responsible for the creation of a rather complex circulation system that includes mountain-valley winds, lake breeze (LB) and non-conventional circulation all induced by the surface non-homogeneous aspect. Results have demonstrated that the implementation of works of such magnitude brings about environmental changes in an area that stretches far beyond the surroundings of the reservoir. The soil cover alterations due to the ever increasing development of the area with the presence of irrigated crops in a sparsely vegetated region ( caatinga) does affect land surface characteristics, occasioning for that matter the splitting of the available energy into latent and sensible heat fluxes. LB behavior varies in accordance with atmospheric conditions and also in view of the type of vegetation found in the lake surrounding areas. Hydro availability in root zones, even under adverse atmospheric conditions (high temperature and low air humidity) brings up the high rates of evaporation and plant transpiration that contribute towards the increase of humidity and the fall of temperature in lower atmospheric layers.

  16. Salt Lake City Area Integrated Projects Electric Power Marketing. Draft environmental impact statement: Volume 1, Summary

    SciTech Connect

    Not Available

    1994-02-01

    The Salt Lake City Area Office of the Western Area Power Administration (Western) markets electricity produced at hydroelectric facilities operated by the Bureau of Reclamation. The facilities are known collectively as the Salt Lake City Area Integrated Projects (SLCA/IP) and include dams equipped for power generation on the Green, Gunnison, Rio Grande, and Colorado rivers and on Deer and Plateau creeks in the states of Wyoming, Utah, Colorado, Arizona, and New Mexico. Of these facilities, only the Glen Canyon Unit, the Flaming Gorge Unit, and the Aspinall Unit (which includes Blue Mesa, Morrow Point, and Crystal dams) are influenced by Western`s power scheduling and transmission decisions. The EIS alternatives, called commitment-level alternatives, reflect combinations of capacity and energy that would feasibly and reasonably fulfill Western`s firm power marketing responsibilities, needs, and statutory obligations. The viability of these alternatives relates directly to the combination of generation capability of the SLCA/IP with energy purchases and interchange. The economic and natural resource assessments in this environmental impact statement (EIS) include an analysis of commitment-level alternatives. Impacts of the no-action altemative are also assessed. Supply options, which include combinations of electrical power purchases and hydropower operational scenarios reflecting different operations of the dams, are also assessed. The EIS evaluates the impacts of these scenarios relative to socioeconomics, air resources, water resources, ecological resources, cultural resources, land use, recreation, and visual resources.

  17. Landsat classification of the barren hydrolittoral areas of Lake Yli-Kitka, north-eastern Finland

    NASA Technical Reports Server (NTRS)

    Raitala, J.; Jantunen, H.; Lampinen, J.

    1987-01-01

    As a part of the project 'Landsat-studies for Mapping the Variables within Water Areas' this study deals with the classification possibilities of evaluating and mapping depth relations and bottom materials within the barren and clear-watered shores of Lake Yli-Kitka, North-Eastern Finland. It has been discovered that it is possible to distinguish open water areas with a water depth of more than about half of the Secchi disk depth from those of shallower hydrolittoral areas. The morainic, sandy and only slightly vegetated subareas of the shallow shores and shoals can possibly be identified by using a simple classification procedure. The data used were recorded by the coarse-resolution Landsat MSS imagery system, and better results are expected after the experiences of the Landsat TM data and the availability of the SPOT material.

  18. Climatic and environmental changes in north-western Russia between 15,000 and 8000 cal yr BP: a review

    NASA Astrophysics Data System (ADS)

    Wohlfarth, Barbara; Lacourse, Terri; Bennike, Ole; Subetto, Dmitry; Tarasov, Pavel; Demidov, Igor; Filimonova, Ludmila; Sapelko, Tatyana

    2007-07-01

    Multi-proxy palaeoenvironmental studies of nine sediment sequences from four areas in north-western Russia reveal significant changes in climate, lake productivity and vegetation during the Lateglacial and early Holocene that show some degree of correlation with changes reconstructed from sites throughout the North Atlantic region. At Lake Nero in the Rostov-Jaroslavl' area, which is outside the maximum limit of the Scandinavian Ice Sheet, sedimentation recommenced shortly after 15 cal ka BP in response to increases in temperature and humidity during Greenland Interstadial 1 (GI-1; Bølling-Allerød). However, climatic amelioration during GI-1 was slow to increase lake organic productivity or trigger large-scale changes in much of northwestern Russia. In general, this region was characterised by long-lasting lake-ice cover, low lake productivity, soil erosion, and dwarf shrub and herb tundra until the end of Greenland Stadial 1 (GS-1; Younger Dryas). At some sites, distinct increases in lake organic productivity, mean summer temperatures and humidity and the expansion of forest trees coincide with rapid warming at the beginning of the Holocene and the increasing influence of warm air masses from the North Atlantic. At other sites, particularly on the Karelian Isthmus, but also in Russian Karelia, the delayed response of limnic and terrestrial environments to early Holocene warming is likely related to the cold surface waters of the Baltic Ice Lake, the proximity of the Scandinavian Ice Sheet and associated strengthened easterlies, and/or extensive permafrost and stagnant ice. These multi-proxy studies underscore the importance of local conditions in modifying the response of individual lakes and their catchments. While Lateglacial vegetation was dominated by Betula nana and Salix shrubs and various herbs, pollen and plant macrofossils suggest that Betula pubescens trees became established as early as 14-13 cal ka BP in the Rostov-Jaroslavl' area. In general, our

  19. Environmental setting of Lake Mead National Recreation Area: Chapter 2 in A synthesis of aquatic science for management of Lakes Mead and Mohave

    USGS Publications Warehouse

    Turner, Kent; Rosen, Michael R.; Holdren, G. Chris; Goodbred, Steven L.; Twichell, David C.

    2012-01-01

    Lakes Mead and Mohave provide opportunities for millions of regional, national, and international visitors to enjoy a wide array of water-based recreation in a spectacular desert setting. The national significance of the site’s recreational opportunities and scientific values led to its designation as the nation’s first National Recreation Area in 1964. The stark contrast of the deep blue lakes with spacious open water basins against a backdrop of mountain and canyon scenery creates a diversity of landscapes inviting recreation from the active to the contemplative (Maxon, 2009). The quality of the setting as a backdrop for the recreational experience has resulted in designation of approximately 200,000 acres of lands surrounding the lakes as wilderness (National Park Service, 2005).

  20. Distribution of native mussel (unionidae) assemblages in coastal areas of Lake Erie, Lake St. Clair, and connecting channels, twenty-five years after a dreissenid invasion

    USGS Publications Warehouse

    Zanatta, David T.; Bossenbroek, Jonathan M.; Burlakova, Lyubov E.; Crail, Todd D.; Szalay, Ferenc de; Griffith, Traci A.; Kapusinski, Douglas; Karatayev, Alexander Y.; Krebs, Robert A.; Meyer, Elizabeth S.; Paterson, Wendy L.; Prescott, Trevor J.; Rowe, Matthew T.; Schloesser, Donald W.; Walsh, Mary C.

    2015-01-01

    Over the past 25 years, unionid mussels in the Laurentian Great Lakes of North America have been adversely impacted by invasive dreissenid mussels, which directly (e.g., by attachment to unionid shells) and indirectly (e.g., by competing for food) cause mortality. Despite the invasion, unionids have survived in several areas in the presence of dreissenid mussels. We investigated current spatial patterns in these native mussel refuges based on surveys for unionid mussels across 48 sampling locations (141 sites) in 2011 and 2012, and documented species abundance and diversity in coastal areas of lakes St. Clair and Erie. The highest-quality assemblages of native mussels (densities, richness, and diversity) appear to be concentrated in the St. Clair delta, where abundance continues to decline, as well as in in Thompson Bay of Presque Isle in Lake Erie and in just a few coastal wetlands and drowned river-mouths in the western basin of Lake Erie. The discovery of several new refuge areas suggests that unionids have a broader distribution within the region than previously thought.

  1. Spring land temperature anomalies in northwestern US and the summer drought over Southern Plains and adjacent areas

    NASA Astrophysics Data System (ADS)

    Xue, Yongkang; Oaida, Catalina M.; Diallo, Ismaila; Neelin, J. David; Li, Suosuo; De Sales, Fernando; Gu, Yu; Robinson, David A.; Vasic, Ratko; Yi, Lan

    2016-04-01

    Recurrent drought and associated heatwave episodes are important features of the US climate. Many studies have examined the connection between ocean surface temperature changes and conterminous US droughts. However, remote effects of large-scale land surface temperature variability, over shorter but still considerable distances, on US regional droughts have been largely ignored. The present study combines two types of evidence to address these effects: climate observations and model simulations. Our analysis of observational data shows that springtime land temperature in northwest US is significantly correlated with summer rainfall and surface temperature changes in the US Southern Plains and its adjacent areas. Our model simulations of the 2011 Southern Plains drought using a general circulation model and a regional climate model confirm the observed relationship between land temperature anomaly and drought, and suggest that the long-distance effect of land temperature changes in the northwest US on Southern Plains droughts is probably as large as the more familiar effects of ocean surface temperatures and atmospheric internal variability. We conclude that the cool 2011 springtime climate conditions in the northwest US increased the probability of summer drought and abnormal heat in the Southern Plains. The present study suggests a strong potential for more skillful intra-seasonal predictions of US Southern Plains droughts when such facts as ones presented here are considered.

  2. A new family of bizarre durophagous carnivorous marsupials from Miocene deposits in the Riversleigh World Heritage Area, northwestern Queensland

    PubMed Central

    Archer, M.; Hand, S. J.; Black, K. H.; Beck, R. M. D.; Arena, D. A.; Wilson, L. A. B.; Kealy, S.; Hung, T.-t.

    2016-01-01

    A new specimen of the bizarrely specialised Malleodectes mirabilis from middle Miocene deposits in the Riversleigh World Heritage Area provides the first and only information about the molar dentition of this strange group of extinct marsupials. Apart from striking autapomorphies such as the enormous P3, other dental features such as stylar cusp D being larger than B suggest it belongs in the Order Dasyuromorphia. Phylogenetic analysis of 62 craniodental characters places Malleodectes within Dasyuromorphia albeit with weak support and without indication of specific relationships to any of the three established families (Dasyuridae, Myrmecobiidae and Thylacinidae). Accordingly we have allocated Malleodectes to the new family, Malleodectidae. Some features suggest potential links to previously named dasyuromorphians from Riversleigh (e.g., Ganbulanyi) but these are too poorly known to test this possibility. Although the original interpretation of a steeply declining molar row in Malleodectes can be rejected, it continues to seem likely that malleodectids specialised on snails but probably also consumed a wider range of prey items including small vertebrates. Whatever their actual diet, malleodectids appear to have filled a niche in Australia’s rainforests that has not been occupied by any other mammal group anywhere in the world from the Miocene onwards. PMID:27229325

  3. A new family of bizarre durophagous carnivorous marsupials from Miocene deposits in the Riversleigh World Heritage Area, northwestern Queensland.

    PubMed

    Archer, M; Hand, S J; Black, K H; Beck, R M D; Arena, D A; Wilson, L A B; Kealy, S; Hung, T-T

    2016-01-01

    A new specimen of the bizarrely specialised Malleodectes mirabilis from middle Miocene deposits in the Riversleigh World Heritage Area provides the first and only information about the molar dentition of this strange group of extinct marsupials. Apart from striking autapomorphies such as the enormous P3, other dental features such as stylar cusp D being larger than B suggest it belongs in the Order Dasyuromorphia. Phylogenetic analysis of 62 craniodental characters places Malleodectes within Dasyuromorphia albeit with weak support and without indication of specific relationships to any of the three established families (Dasyuridae, Myrmecobiidae and Thylacinidae). Accordingly we have allocated Malleodectes to the new family, Malleodectidae. Some features suggest potential links to previously named dasyuromorphians from Riversleigh (e.g., Ganbulanyi) but these are too poorly known to test this possibility. Although the original interpretation of a steeply declining molar row in Malleodectes can be rejected, it continues to seem likely that malleodectids specialised on snails but probably also consumed a wider range of prey items including small vertebrates. Whatever their actual diet, malleodectids appear to have filled a niche in Australia's rainforests that has not been occupied by any other mammal group anywhere in the world from the Miocene onwards. PMID:27229325

  4. A new family of bizarre durophagous carnivorous marsupials from Miocene deposits in the Riversleigh World Heritage Area, northwestern Queensland

    NASA Astrophysics Data System (ADS)

    Archer, M.; Hand, S. J.; Black, K. H.; Beck, R. M. D.; Arena, D. A.; Wilson, L. A. B.; Kealy, S.; Hung, T.-T.

    2016-05-01

    A new specimen of the bizarrely specialised Malleodectes mirabilis from middle Miocene deposits in the Riversleigh World Heritage Area provides the first and only information about the molar dentition of this strange group of extinct marsupials. Apart from striking autapomorphies such as the enormous P3, other dental features such as stylar cusp D being larger than B suggest it belongs in the Order Dasyuromorphia. Phylogenetic analysis of 62 craniodental characters places Malleodectes within Dasyuromorphia albeit with weak support and without indication of specific relationships to any of the three established families (Dasyuridae, Myrmecobiidae and Thylacinidae). Accordingly we have allocated Malleodectes to the new family, Malleodectidae. Some features suggest potential links to previously named dasyuromorphians from Riversleigh (e.g., Ganbulanyi) but these are too poorly known to test this possibility. Although the original interpretation of a steeply declining molar row in Malleodectes can be rejected, it continues to seem likely that malleodectids specialised on snails but probably also consumed a wider range of prey items including small vertebrates. Whatever their actual diet, malleodectids appear to have filled a niche in Australia’s rainforests that has not been occupied by any other mammal group anywhere in the world from the Miocene onwards.

  5. Partners in flight bird conservation plan for the Upper Great Lakes Plain (Physiographic Area 16)

    USGS Publications Warehouse

    Knutson, M.G.; Butcher, G.; Fitzgerald, J.; Shieldcastle, J.

    2001-01-01

    1 November 2001. Conservation of bird habitats is a major focus of effort by Partners in Flight, an international coalition of agencies, citizens, and other groups dedicated to 'keeping common birds common'. USGS worked on a planning team to publish a bird conservation plan for the Upper Great Lakes Plain ecoregion (PIF 16), which includes large portions of southern Wisconsin, southern Michigan and parts of Minnesota, Iowa, Illinois, Indiana, and Ohio. The conservation plan outlines specific habitat restoration and bird population objectives for the ecoregion over the next decade. The plan provides a context for on-the-ground conservation implementation by the US Fish and Wildlife Service, the USDA Natural Resources Conservation Service, the US Forest Service, states, and conservation groups. Citation: Knutson, M. G., G. Butcher, J. Fitzgerald, and J. Shieldcastle. 2001. Partners in Flight Bird Conservation Plan for The Upper Great Lakes Plain (Physiographic Area 16). USGS Upper Midwest Environmental Sciences Center in cooperation with Partners in Flight, La Crosse, Wisconsin. Download from website: http://www.blm.gov/wildlife/pifplans.htm. The Upper Great Lakes Plain covers the southern half of Michigan, northwest Ohio, northern Indiana, northern Illinois, southern Wisconsin, and small portions of southwest Minnesota and northwest Iowa. Glacial moraines and dissected plateaus are characteristic of the topography. Broadleaf forests, oak savannahs, and a variety of prairie communities are the natural vegetation types. A oDriftless Areao was not glaciated during the late Pleistocene and emerged as a unique area of great biological diversity. Priority bird species for the area include the Henslow's Sparrow, Sedge Wren, Bobolink, Golden-winged Warbler, Cerulean Warbler, Black-billed Cuckoo, and Red-headed Woodpecker. There are many large urban centers in this area whose growth and sprawl will continue to consume land. The vast majority of the presettlement forest and

  6. Seismicity of the Lake Tahoe-Reno Area, Nevada and California

    NASA Astrophysics Data System (ADS)

    Smith, K. D.; Hauksson, S. E.

    2010-12-01

    Earthquakes in Lake-Tahoe Reno area are relocated with phase and waveform cross-correlation data using USGS application HYPODD. An approximately 10 km wide zone of seismicity extends from near Tahoe City, California eastward into south urban Reno. It represents one of several similar northeast trending zones of deformation and seismicity along the Walker Lane Belt of the western Great Basin. The area directly north of Lake Tahoe area is located in the transition between north-striking normal faulting systems that make up the Sierran frontal fault zone, to the south, and primary right-lateral strike slip fault zones of the northern Walker Lane Belt, to the north. Whereas the major normal faults along the Sierran front near the Reno-Tahoe area show little micro-earthquake activity, slip transfer regions, similar to what we observe north of Lake Tahoe include persistent seismicity, most likely involving numerous faults within an area distributed deformation. Although the fairly well defined northeast trend of seismicity north of Lake Tahoe includes M ~4+ left-lateral strike slip events consistent with the general orientation of the activity, right-lateral and normal faulting M ~4 earthquakes also occur along the trend. Additionally, portions of this northeast trending zone of activity consist of northwesterly alignments of small magnitude events and localized clusters of seismicity. The distributed seismicity and variety of focal mechanisms most likely reflects the transition from primary normal faulting to strike-slip faulting from south to north. The T-axes from earthquake focal mechanisms are oriented E-W at this latitude along the Sierran front. At its western extent, North Tahoe activity joins with northwest trending alignments of small magnitude events that evolve northwestward into the Mohawk Valley fault zone, near Sierraville, California. Its eastern extent, in south Reno, is nearly coincident with the southeastern limit of the 2008 Mogul-Somersett earthquake

  7. 78 FR 72605 - Special Regulations, Areas of the National Park System, Lake Meredith National Recreation Area...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-03

    ... contain a full description of the purpose and need for taking action, the alternatives considered, public... revisions to 36 CFR 4.30 (as stated in the preamble to the final rule which can be found at 77 FR 39927... effects on other areas. A Federalism summary impact statement is not required. Civil Justice...

  8. Geothermal exploration assessment and interpretation, Upper Klamah Lake Area, Klamath Basin, Oregon

    SciTech Connect

    Stark, M.; Goldstein, N.E.; Wollenberg, H.A.

    1980-09-01

    Data from public and private sources on the Klamath Basin geothermal resource are reviewed, synthesized, and reinterpreted. In this, the second and final phase of the work, geological, remote sensing, geochemical, temperature gradient, gravity, aeromagnetic, and electrical resistivity data sets are examined. These data were derived from surveys concentrated on the east and west shores of Upper Klamath Lake. The geological, remote sensing, and potential field data suggest a few northeast-trending discontinuities, which cross the regional north-westerly strike. The near-surface distribution of warm water appears to be related to the intersections of these lineaments and northwest-trending faults. The groundwater geochemical data are reviewed and the various reservoir temperature estimates compared. Particular attention is given to specific electrical conductivities of waters as an interpretational aid to the subsurface resistivity results. A clear trend emerges in the Klamath Falls/Olene Gap area; hotter waters are associated with higher specific conductivities. In the Nuss Lake/Stukel Mountain area the opposite trend prevails, although the relationship is somewhat equivocal.

  9. Digital data sets that describe aquifer characteristics of the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma

    USGS Publications Warehouse

    Adams, G.P.; Runkle, D.L.; Rea, Alan

    1997-01-01

    ARC/INFO export and nonproprietary format files This diskette contains digitized aquifer boundaries and maps of of hydraulic conductivity, recharge, and ground-water level elevation contours for the alluvial and terrace deposits along the alluvial and terrace deposits along the Beaver-North Canadian River from the panhandle to Canton Lake in northwestern Oklahoma. Ground water in 830 square miles of the Quaternary-age alluvial and terrace aquifer is an important source of water for irrigation, industrial, municipal, stock, and domestic supplies. The aquifer consists of poorly sorted, fine to coarse, unconsolidated quartz sand with minor amounts of clay, silt, and basal gravel. The hydraulically connected alluvial and terrace deposits unconformably overlie the Tertiary-age Ogallala Formation and Permian-age formations. Most of the lines in the aquifer boundary and recharge data sets and some of the lines in the hydraulic conductivity data set were extracted from a published digital surficial geology data set based on a scale of 1:250,000. The ground-water elevation contours and some of the lines for the aquifer boundary, hydraulic conductivity, and recharge data sets were digitized from a ground-water modeling report about the aquifer published at a scale of 1:250,000. The hydraulic conductivity values and recharge rates also are from the ground-water modeling report. The data sets are provided in both nonproprietary and ARC/INFO export file formats. Ground-water flow models are numerical representations that simplify and aggregate natural systems. Models are not unique; different combinations of aquifer characteristics may produce similar results. Therefore, values of hydraulic conductivity and recharge used in the model and presented in this data set are not precise, but are within a reasonable range when compared to independently collected data.

  10. Effects of wetlands on quality of runoff entering lakes in the Twin Cities Metropolitan Area, Minnesota

    USGS Publications Warehouse

    Brown, R.G.

    1985-01-01

    Four wetlands were compared with respect to their effectiveness in decreasing suspended solids and nutrient concentrations in runoff to lakes immediately downstream from the wetlands. An artificial impoundment in one of the wetlands increased settling of suspended solids. A decrease of nutrients in this wetland was probably the result of high assimilation rates associated with a dense stand of cattails. Two of the other three wetlands consist of open water and land areas, both of which contain abundant vegetation. Drainage from land areas within the wetlands may have lowered the overall effectiveness of the wetlands in decreasing sediment and nutrient concentrations. The third wetland was a constructed wetland that was ineffective in decreasing sediment or nutrient concentrations because its storage capacity was too small to prevent frequent flushing of accumulated sediment. Sediment concentrations in discharge from this wetland were as much as 22 times greater than the already high sediment concentrations in the inflow. (Author 's abstract)

  11. Potential flood and debris hazards at Cottonwood Cove, Lake Mead National Recreation Area, Clark County, Nevada

    USGS Publications Warehouse

    Moosburner, Otto

    1981-01-01

    At Cottonwood Cove, Nevada, most of the existing dikes at the recreation sites are effective in diverting and routing floodflows, up to and including the 100-year flood, away from people and facilities. The dikes across Ranger Residence Wash and Access Road Wash at the mouth divert floods up to the 50-year recurrence interval away from residential areas. Flow and debris damage in protected areas will be relatively minor minor for floods including the 100-year flood, whereas damage caused by sediment deposition at the mouths of the washes near Lake Mohave could be significant for floods equal to or less than the 100-year flood. The extreme flood, a flood meteorologically and hydrologically possible but so rare as to preclude a frequency estimate, could cause great damage and possible loss of life. The present dikes would be topped or breached by such flooding. (USGS)

  12. [Environmental cost of rice production in Dongting Lake area of Hunan Province].

    PubMed

    Xiang, Ping'an; Huang, Huang; Yan, Huimin; Zhou, Yan; Zheng, Hua; Huang, Xingguo

    2005-11-01

    To evaluate the environmental cost of rice production is of significance for the sustainable development of agriculture and the set-up of green GDP accounting system. In this paper, the environmental cost of rice production in Dongting Lake area, one of the main bread baskets in China, was evaluated from the aspects of pesticide pollution, chemical fertilizer pollution, greenhouse gases emission, plastic film persistence, paddyfield gleyization, and polderization. The results showed that in 1999, the total environmental cost of rice production in this area was 41.91 billion yuan, equivalent to 26.8% of its total agricultural production value, or 28.5% of the gross output of its planting industry. For the sustainable production of rice, the strategies for decrease environmental cost intrinsically were put forward. PMID:16471365

  13. Geological applications of LANDSAT-1 imagery to the Great Salt Lake area

    NASA Technical Reports Server (NTRS)

    Anderson, A. T.; Smith, A. F.

    1975-01-01

    The ERTS program has been designed as a research and development tool to demonstrate that remote sensing from orbital altitudes is a feasible and practical approach to efficient management of earth resources. From this synoptic view and repetitive coverage provided by ERTS imagery of the Great Salt Lake area, large geological and structural features, trends, and patterns have been identified and mapped. A comparative analysis of lineaments observed in September and December data was conducted, existing mineral locations were plotted, and areas considered prospective for mineralization based on apparent structure-mineralization relationships were defined. The additional information obtained using ERTS data provides an added source of information to aid in the development of more effective mineral exploration programs.

  14. 33 CFR 334.750 - Ben's Lake, a tributary of Choctawhatchee Bay, Fla., at Eglin Air Force Base; restricted area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Choctawhatchee Bay, Fla., at Eglin Air Force Base; restricted area. 334.750 Section 334.750 Navigation and... RESTRICTED AREA REGULATIONS § 334.750 Ben's Lake, a tributary of Choctawhatchee Bay, Fla., at Eglin Air Force..., without the permission of the Commander, Eglin Air Force Base, Florida, or his authorized...

  15. 33 CFR 334.750 - Ben's Lake, a tributary of Choctawhatchee Bay, Fla., at Eglin Air Force Base; restricted area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Choctawhatchee Bay, Fla., at Eglin Air Force Base; restricted area. 334.750 Section 334.750 Navigation and... RESTRICTED AREA REGULATIONS § 334.750 Ben's Lake, a tributary of Choctawhatchee Bay, Fla., at Eglin Air Force..., without the permission of the Commander, Eglin Air Force Base, Florida, or his authorized...

  16. The relative mobility of U, Th and Ra isotopes in the weathered zones of the Eye-Dashwa Lakes granite pluton, northwestern Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Latham, A. G.; Schwarcz, H. P.

    1987-10-01

    Radioisotope activity ratios of weathered surface rocks from the Eye-Dashwa Lakes granite pluton show that, in the 238U decay series, 226Ra has been leached more rapidly than the grandparent 234U and 238U isotopes. The observation of 238Th /232Th disequilibria in the 232Th decay series shows that either 228Th (half-life of 1.9 yrs) or 228Ra (half-life of 5.75 yrs) have been removed from these rocks very rapidly indeed. Isotope ratios of separated mineral fractions appear to show that whereas uranium tends to be removed from all mineral fractions, Ra is strongly readsorbed onto feldspars, presumably as these undergo alteration to clay minerals. This necessitates making a distinction between intermineral mobility of U or Ra, and the net loss of U or Ra from the whole rock. An attempt has been made to model, quantitatively, the transport rate of Ra, though with little success. Failure of the modelling appears to indicate that the mobility of 228Ra is higher than might be predicted by the mobility of 226Ra; that is, the two isotopes are not strict analogues of one another in their response to initial weathering.

  17. Information support of territorial wildlife management of Lake Baikal and the surrounding areas (Russia)

    NASA Astrophysics Data System (ADS)

    Lesnykh, Svetlana

    2013-04-01

    The UNESCO World Heritage Committee inscribed Lake Baikal in the World Heritage List under all four natural criteria as the most outstanding example of a freshwater ecosystem. It is the oldest and deepest lake in the world, which is the main freshwater reserve surrounded by a system of protected areas that have high scientific and natural values. However, there is a conflict between three main interests within the territory: the preservation of the unique ecosystem of the lake and its surrounding areas, the need for regional economic development, and protection of interests of the population, living on the shores of Lake Baikal. Solutions to the current challenges are seen in the development of control mechanisms for the wildlife management to ensure sustainable development and conservation of lake and the surrounding regions. For development mechanisms of territorial management of the complex and valuable area it is necessary to analyze features of its functioning and self-control (adaptable possibilities), allowing ecosystems to maintain their unique properties under influence of various external factors: anthropogenic (emissions, waste water, streams of tourists) and natural (climate change) load. While determining the direction and usage intensity of the territory these possibilities and their limits should be considered. Also for development of management strategy it is necessary to consider the relation of people to land and water, types of wildlife management, ownership, rent, protection from the negative effects, and etc. The relation of people to the natural area gives a chance to prioritize the direction in the resource use and their protection. Results of the scientific researches (reaction of an ecosystem on influence of various factors and system of relations to wildlife management objects) are the basis for the nature protection laws in the field of wildlife management and environmental protection. The methodology of legal zoning of the territory was

  18. [Hydrogen and oxygen isotopes of lake water and geothermal spring water in arid area of south Tibet].

    PubMed

    Xiao, Ke; Shen, Li-Cheng; Wang, Peng

    2014-08-01

    The condition of water cycles in Tibet Plateau is a complex process, and the hydrogen and oxygen isotopes contain important information of this process. Based on the analysis of isotopic composition of freshwater lake, saltwater lake and geothermal water in the southern Tibetan Plateau, this study investigated water cycling, composition and variation of hydrogen and oxygen isotopes and the influencing factors in the study area. The study found that the mean values of delta18O and deltaD in Daggyaima lake water (-17.0 per thousand for delta18O and -138. 6 per thousand for deltaD), Langcuo lake water (-6.4 per thousand for delta18O and -87.4 per thousand for deltaD) and Dagejia geothermal water (-19.2 per thousand for delta18 and -158.2 per thousand for deltaD) all showed negative delta18O and deltaD values in Tibetan Plateau by the influence of altitude effects. Lake water and geothermal water were influenced by evaporation effects in inland arid area, and the slope of evaporation line was less than 8. Deuterium excess parameters of lake water and geothermal water were all negative. The temperature of geothermal reservoirs in Dagejia geothermal field was high,and oxygen shift existed in the relationship of hydrogen and oxygen isotopes. PMID:25338365

  19. Water management sustainability in reclaimed coastal areas. The case of the Massaciuccoli lake basin (Tuscany, Italy)

    NASA Astrophysics Data System (ADS)

    Rossetto, Rudy; Baneschi, Ilaria; Basile, Paolo; Guidi, Massimo; Pistocchi, Chiara; Sabbatini, Tiziana; Silvestri, Nicola; Bonari, Enrico

    2010-05-01

    The lake of Massaciuccoli (7 km2 wide and about 2 m deep) and its palustrine nearby areas (about 13 km2 wide) constitute a residual coastal lacustrine and marshy area largerly drained by 1930. In terms of hydrological boundaries, the lake watershed is bordered by carbonate to arenaceous reliefs on the east, by a sandy coastal shallow aquifer on the west (preventing groundwater salinisation), while south and north by the Serchio River and the Burlamacca-Gora di Stiava channels alignment respectively. Since reclamation of the peaty soils started, subsidence began (2 to 3 m in 70 years), leaving the lake perched and central respect the low drained area, now 0 to -3 m below m.s.l., and requiring 16 km embankment construction. During the dry summer season, the lake undergoes a severe water stress, that, along with nutrients input, causes the continuous ecosystem degradation resulting in water salinisation and eutrophication. Water stress results in a head decrease below m.s.l., causing seawater intrusion along the main outlet, and reaching its highest point at the end of the summer season (common head values between -0.40 and -0.5 a.m.s.l.). The water budget for an average dry season lasting about 100 days was computed, considering a 10% error, in order to understand and evaluate all the components leading to the above mentioned water stress by means of several multidisciplinary activities during the years 2008-2009. They started with a thoroughly literature review, continued with hydrological, hydrogeochemical monitoring and testing (both for surface water and the shallow aquifer) and agronomical investigations (to characterize cropping systems, evapotranspiration rates and irrigation schemes). All the collected data were then processed by means of statistical methods, time series analysis, numerical modelling of the shallow aquifer and hydrological modelling. The results demonstrate the presence of two interrelated hydrological sub-systems: the lake and the reclaimed

  20. Lake evolution of the terminal area of Shiyang River drainage in arid China since the last glaciation

    USGS Publications Warehouse

    Shi, Q.; Chen, F.-H.; Zhu, Y.; Madsen, D.

    2002-01-01

    Investigations of geomorphology and sedimentology, and analyses of radiocarbon dates, grain size and carbonate of the sediment at the present-dry closed basin in the terminal area of Shiyang River in arid China were conducted to recover the history of palaeolake change since the last glacial. The terminal area was covered by eolian sand before 13,000 14C BP. Lacustrine deposits covered the eolian sand after 13,000 14C BP, but were succeeded rapidly by eolian or fluvial deposits ca. 11,200-10,000 BP. This fact plus the grain-size distribution and CaCO3 content showed that climate was extremely dry during the last glacial, but wet-dry oscillations characterized the late glacial. A single coalescent lake, over 45 m deep and 2130 km2, formed between 10,000-6400 14C BP in the basin. The lake disintegrated into several shallow carbonate lakes or swamps gradually after 6400 14C BP. Eolian sand reached into the most part of the basin during the period. The lake evolution in the area generally reflects the East Asian summer monsoon history forced by Northern hemisphere insolation. Short time-scale lake fluctuations also existed in the area since the last glacial. ?? 2002 Elsevier Science Ltd and INQUA. All rights reserved.

  1. SPIRIT LAKE, KOOTENAI COUNTY, IDAHO - WATER QUALITY STATUS REPORT, 1987

    EPA Science Inventory

    Spirit Lake is a high quality recreational lake located in northwestern Kootenai County, Idaho (17010214). A 1984 water quality assessment indicated nutrient enrichment from nonpoint sources, such as timber harvest and domestic wastewater, were causing increased aquatic plant gr...

  2. Land-Surface Subsidence in the Area of Moses Lake Near Texas City, Texas

    USGS Publications Warehouse

    Gabrysch, R.K.; Bonnet, C.W.

    1976-01-01

    Removal of water, oil, and gas from the subsurface in Harris and Galveston Counties has caused declines in fluid pressures, which in turn have resulted in subsidence of the land surface. Subsidence of the land surface at Moses Lake in due principaly to the removal of ground water in adjacent areas. Significant subsidence of the land surface at Moses Lake began after 1900, and as much as 1.8 feet of subsidence had occurred in the ara by 1973. Probably future subsidence was calculated by two methods for two loading situations. In the first loading situation, the artesian head in the middle Chicot aquifer, in the Alta Loma Sand (Rose, 1943), and in the Evangeline aquifer would continue to decline at respective rates of 1, 3, and 3 feet per year until 1980 and then cease. In the second loading situation, the artesian head in the middle Chicot aquifer, in the Alta Loma Sand, and in the Evangeline aquifer would continue to decline at respective rates of 1, 3, and 3 feet per year until 1990 and then cease. (Woodard-USGS)

  3. Community health profile of Windsor, Ontario, Canada: anatomy of a Great Lakes area of concern.

    PubMed Central

    Gilbertson, M; Brophy, J

    2001-01-01

    The rates of mortality, morbidity as hospitalizations, and congenital anomalies in the Windsor Area of Concern ranked among the highest of the 17 Areas of Concern on the Canadian side of the Great Lakes for selected end points that might be related to pollution in this relatively highly industrialized city. Mortality and morbidity rates from all causes were higher than in the rest of the province. Anomalously high rates of diseases included various cancers; endocrine, nutritional, metabolic, and immunity disorders; diseases of the blood and blood-forming organs, nervous system and sense organs, circulatory and respiratory systems, digestive system, genitourinary system, skin and subcutaneous tissue, musculoskeletal system and connective tissues; congenital anomalies, and infant mortality. Of particular concern was the early onset of the elevated rates of many of these diseases and conditions. Comparison of these incident rates with those in Hamilton, another industrial municipality in southern Ontario, suggested that in addition to a variety of local sources of industrial pollution from automobile manufacturing and use, transboundary air and water pollution from Detroit, Michigan, should be investigated as potentially important causes of these health outcomes in the Windsor Area of Concern. Some of the institutional and political trends of the past decade may need to be reversed before effective remedial programs are implemented for cleaning up contaminated sediments and for containment of leaking hazardous waste sites. This pilot project would seem to be a useful preliminary method of integrating human health concerns and of priority setting for the administration of the Great Lakes Water Quality Agreement and the Canada-United States Air Quality Agreement. PMID:11744501

  4. The influence of natural and human factors in the shrinking of the Ebinur Lake, Xinjiang, China, during the 1972-2013 period.

    PubMed

    Zhang, Fei; Tiyip, Tashpolat; Johnson, Verner Carl; Kung, Hsiang-te; Ding, Jian-li; Sun, Qian; Zhou, Mei; Kelimu, Ardak; Nurmuhammat, Ilyas; Chan, Ngai Weng

    2015-01-01

    The Ebinur Lake is a closed inland lake located within the arid region of the Xinjiang Autonomous Region in the northwestern part of China, near the Kazakhstan border. The shrinkage of the lake area is believed to be caused by ecological environmental deterioration and has become an important restraining factor for the social development of the local population. Of all the lakes in the Xinjiang Autonomous Region, the Ebinur Lake is the most severely impacted water body. The lake has undergone change in size naturally for over thousands of years due to natural causes. However, the authors observed the dramatic changes in the freshwater resources of this region from the aerial images from 1972 to 2013. Thus, this paper traces and analyzes the change in the Ebinur Lake surface area in the past 41 years. A set of six satellite images acquired between 1972 and 2013 was employed to map the change in the surface area of the Ebinur Lake using the water index approach. The authors applied the traditional normalized difference water index (NDWI) and the modified normalized difference water index (MNDWI) to quantify the change in the water body area of the Ebinur Lake during the study period. The results indicate that the lake area has experienced a dramatic decrease of 31.4% from 1972 to 2013. The paper also examines the natural processes and human activities that may have contributed to the decrease in the lake area. The results show that the decrease in total lake area appears to coincide with periods of rapid land reclamation in the study area. Moreover, the uncontrolled land reclamation activities, such as irrigation, can increase the sedimentation in the Ebinur Lake thereby reducing the lake size. Reduction of the lake area has a negative ecological impact on the environment and on human life and property. The lake area is the most important factor to ensure the environment of the watershed and the key index to measure the environment balance. PMID:25410947

  5. Closure Report for Corrective Action Unit 425: Area 9 Main Lake Construction Debris Disposal Area, Tonopah Test Range, Nevada

    SciTech Connect

    K. B. Campbell

    2003-03-01

    Corrective Action Unit (CAU) 425 is located on the Tonopah Test Range, approximately 386 kilometers (240 miles) northwest of Las Vegas, Nevada. CAU 425 is listed in the Federal Facility Agreement and Consent Order (FFACO, 1996) and is comprised of one Corrective Action Site (CAS). CAS 09-08-001-TA09 consisted of a large pile of concrete rubble from the original Hard Target and construction debris associated with the Tornado Rocket Sled Tests. CAU 425 was closed in accordance with the FFACO and the Nevada Division of Environmental Protection-approved Streamlined Approach for Environmental Restoration Plan for CAU 425: Area 9 Main Lake Construction Debris Disposal Area, Tonopah Test Range, Nevada (U.S. Department of Energy, Nevada Operations Office, 2002). CAU 425 was closed by implementing the following corrective actions: The approved corrective action for this unit was clean closure. Closure activities included: (1) Removal of all the debris from the site. (2) Weighing each load of debris leaving the job site. (3) Transporting the debris to the U.S. Air Force Construction Landfill for disposal. (4) Placing the radioactive material in a U.S. Department of Transportation approved container for proper transport and disposal. (5) Transporting the radioactive material to the Nevada Test Site for disposal. (6) Regrading the job site to its approximate original contours/elevation.

  6. Response of lake chemistry to changes in atmospheric deposition and climate in three high-elevation wilderness areas of Colorado

    USGS Publications Warehouse

    Mast, M.A.; Turk, J.T.; Clow, D.W.; Campbell, D.H.

    2011-01-01

    Trends in precipitation chemistry and hydrologic and climatic data were examined as drivers of long-term changes in the chemical composition of high-elevation lakes in three wilderness areas in Colorado during 1985-2008. Sulfate concentrations in precipitation decreased at a rate of -0.15 to -0.55 ??eq/l/year at 10 high-elevation National Atmospheric Deposition Program stations in the state during 1987-2008 reflecting regional reductions in SO2 emissions. In lakes where sulfate is primarily derived from atmospheric inputs, sulfate concentrations also decreased although the rates generally were less, ranging from -0.12 to -0.27 ??eq/l/year. The similarity in timing and sulfur isotopic data support the hypothesis that decreases in atmospheric deposition are driving the response of high-elevation lakes in some areas of the state. By contrast, in lakes where sulfate is derived primarily from watershed weathering sources, sulfate concentrations showed sharp increases during 1985-2008. Analysis of long-term climate records indicates that annual air temperatures have increased between 0.45 and 0.93??C per decade throughout most mountainous areas of Colorado, suggesting climate as a factor. Isotopic data reveal that sulfate in these lakes is largely derived from pyrite, which may indicate climate warming is preferentially affecting the rate of pyrite weathering. ?? 2010 US Government.

  7. Response of lake chemistry to changes in atmospheric deposition and climate in three high-elevation wilderness areas of Colorado

    USGS Publications Warehouse

    Mast, M. Alisa; Turk, John T.; Clow, David W.; Campbell, Donald D.

    2011-01-01

    Trends in precipitation chemistry and hydrologic and climatic data were examined as drivers of long-term changes in the chemical composition of high-elevation lakes in three wilderness areas in Colorado during 1985-2008. Sulfate concentrations in precipitation decreased at a rate of -0.15 to -0.55 μeq/l/year at 10 high-elevation National Atmospheric Deposition Program stations in the state during 1987-2008 reflecting regional reductions in SO2 emissions. In lakes where sulfate is primarily derived from atmospheric inputs, sulfate concentrations also decreased although the rates generally were less, ranging from -0.12 to -0.27 μeq/l/year. The similarity in timing and sulfur isotopic data support the hypothesis that decreases in atmospheric deposition are driving the response of high-elevation lakes in some areas of the state. By contrast, in lakes where sulfate is derived primarily from watershed weathering sources, sulfate concentrations showed sharp increases during 1985-2008. Analysis of long-term climate records indicates that annual air temperatures have increased between 0.45 and 0.93°C per decade throughout most mountainous areas of Colorado, suggesting climate as a factor. Isotopic data reveal that sulfate in these lakes is largely derived from pyrite, which may indicate climate warming is preferentially affecting the rate of pyrite weathering.

  8. Lake Eyre

    Atmospheric Science Data Center

    2013-04-16

    ...   View Larger Image Lake Eyre is a large salt lake situated between two deserts in one of Australia's driest regions. ... the effect of sunglint at the nadir camera view angle. Dry, salt encrusted parts of the lake appear bright white or gray. Purple areas have ...

  9. The Influence of Allochthonous Leaf Detritus on the Occurrence of Crustacean Detritivores in the Soft-bottom Macrobenthos of the Po River Delta Area (northwestern Adriatic Sea)

    NASA Astrophysics Data System (ADS)

    Mancinelli, G.; Rossi, L.

    2002-05-01

    Core samples were examined quarterly at two coastal sites (S1 and S2) and at an offshore station (S3) located in the Po River delta area (northwestern Adriatic Sea). Analyses focused on (i) occurrence of coarse detritus of allochthonous origin in the sedimentary matrix and (ii) the relative influence of macrodetritus enrichment and other environmental factors on the vagile macrofauna. Plant debris occurred in site S1 sediments only in summer and autumn; in contrast, fragments of the phanerogams Cymodocea nodosa and Zostera spp. were found in site S2 sediment throughout the sampling period. Sediments from the offshore site S3 were characterized by negligible plant material, even though in summer and autumn samples debris of continental origin was observed. Even though leaf detritus occurrence at site S2 was ∼5-fold higher compared to the other coastal site S1, it did not influence the total organic matter and its distribution among grain-size classes. Conversely, the specific organic content of dimensional fractions provided an effective assessment of detritus enrichment processes occurring at the two coastal sites. A group of brackish-originated crustaceans (i.e. the amphipods Gammarus insensibilis and G. aequicauda and the isopod Idotea baltica) was the main determinant of among-site multivariate differences in the vagile macrofauna; depositivorous ophiuroids accounted for the residual differences observed during the study period. The analysis of taxa abundance and individual body size indicated that in both site S1 and S3 macrodetritus advection to the benthic system corresponded with passive dispersal of brackish crustaceans, that provided a negligible contribution to the macrobenthic production. In contrast, in site S2 allochthonous inputs from marginal environments could have represented the key factor for the persistence of an authochthonous population of Gammarus insensibilis. The amphipod provided a considerable (19·4%) contribution to the total

  10. Cretaceous plutonic rocks in the Donner Lake-Cisco Grove area, northern Sierra Nevada, California

    USGS Publications Warehouse

    Kulow, Matthew J.; Hanson, Richard E.; Girty, Gary H.; Girty, Melissa S.; Harwood, David S.

    1998-01-01

    The northernmost occurrences of extensive, glaciated exposures of the Sierra Nevada batholith occur in the Donner Lake-Cisco Grove area of the northern Sierra Nevada. The plutonic rocks in this area, which are termed here the Castle Valley plutonic assemblage, crop out over an area of 225 km2 and for the most part are shown as a single undifferentiated mass on previously published geological maps. In the present work, the plutonic assemblage is divided into eight separate intrusive units or lithodemes, two of which each consist of two separate plutons. Compositions are dominantly granodiorite and tonalite, but diorite and granite form small plutons in places. Spectacular examples of comb layering and orbicular texture occur in the diorites. U-Pb zircon ages have been obtained for all but one of the main units and range from ~120 to 114 Ma, indicating that the entire assemblage was emplaced in a narrow time frame in the Early Cretaceous. This is consistent with abundant field evidence that many of the individual phases were intruded penecontemporaneously. The timing of emplacement correlates with onset of major Cretaceous plutonism in the main part of the Sierra Nevada batholith farther south. The emplacement ages also are similar to isotopic ages for gold-quartz mineralization in the Sierran foothills west of the study area, suggesting a direct genetic relationship between the voluminous Early Cretaceous plutonism and hydrothermal gold mineralization.

  11. Analyses and descriptions of geochemical samples, Mountain Lake Wilderness Study Area, Virginia and West Virginia

    USGS Publications Warehouse

    Mei, Leung; Fletcher, J.D.; Rait, Norma; Lesure, F.G.

    1978-01-01

    Semiquantitative emission spectrographic analyses for 64 elements on 95 stream sediment and 122 rock samples from Mountain Lake Wilderness Study Area, Giles and Craig Counties, Virginia and Monroe County, West Virginia, are reported here in detail. Locations for all samples are in Universal Transverse Mercator (UTM) coordinates. Brief descriptions of rock samples are also included. Rocks analysed are mostly sandstone. Samples of hematitic sandstone of the Rose Hill Formation and limonite-cemented sandstone of the Rocky Gap Sandstone contain high values of iron; these rocks are submarginal iron resources. Some of these iron-rich samples have a little more barium, copper, cobalt, lead, silver, and/or zinc than in average sandstone, but they do not suggest the presence of economic deposits of these metals. A few samples of Tuscarora Quartzite contain moderate amounts of manganese. These are from a submarginal manganese resource. No other obviously anomalous-values related to mineralized rock are present in the data.

  12. Chemico/biological investigation of contaminated sediment from the Hamilton Harbour area of western Lake Ontario

    SciTech Connect

    Marvin, C.H.; Allan, L.; McCarry, B.E.; Bryant, D.W. )

    1993-01-01

    Highly contaminated sediment from the Hamilton Harbour area of western Lake Ontario was examined using a bioassay-directed fractionation methodology. A sediment sample was extracted using a Soxhlet apparatus and the resulting extract was fractionated into compound classes using an alumina clean-up step and high performance liquid chromatographic techniques. The resulting fractions were subjected to bioassays using TA98- and TA100-like strains modified by the inclusion of genes for the activating enzymes nitroreductase and O-acetyl-transferase. The majority of the mutagenic activity displayed by the sample extract was found to be present in the fraction containing the polycyclic aromatic hydrocarbons (PAH). Extracts of the PAH-containing fraction displayed dramatically higher responses with the TA100 type strains with metabolic activation. Further separation of the PAH-containing fraction showed the majority of the biological activity coeluted with PAH having molecular masses of 276, 278, and 302 amu.

  13. Changes in streamflow and summary of major-ion chemistry and loads in the North Fork Red River basin upstream from Lake Altus, northwestern Texas and western Oklahoma, 1945-1999

    USGS Publications Warehouse

    Smith, S. Jerrod; Wahl, Kenneth L.

    2003-01-01

    Upstream from Lake Altus, the North Fork Red River drains an area of 2,515 square miles. The quantity and quality of surface water are major concerns at Lake Altus, and water-resource managers and consumers need historical information to make informed decisions about future development. The Lugert-Altus Irrigation District relies on withdrawals from the lake to sustain nearly 46,000 acres of agricultural land. Kendall's tau tests of precipitation data indicated no statistically significant trend over the entire 100 years of available record. However, a significant increase in precipitation occurred in the last 51 years. Four streamflow-gaging stations with more than 10 years of record were maintained in the basin. These stations recorded no significant trends in annual streamflow volume. Two stations, however, had significant increasing trends in the base-flow index, and three had significant decreasing trends in annual peak flows. Major-ion chemistry in the North Fork Red River is closely related to the chemical composition of the underlying bedrock. Two main lithologies are represented in the basin upstream from Lake Altus. In the upper reaches, young and poorly consolidated sediments include a range of sizes from coarse gravel to silt and clay. Nearsurface horizons commonly are cemented as calcium carbonate caliche. Finer-grained gypsiferous sandstones and shales dominate the lower reaches of the basin. A distinct increase in dissolved solids, specifically sodium, chloride, calcium, and sulfate, occurs as the river flows over rocks that contain substantial quantities of gypsum, anhydrite, and dolomite. These natural salts are the major dissolved constituents in the North Fork Red River.

  14. Decadal dynamics of lake inundation areas in the Yangtze Basin downstream from the Three Gorges Reservoir (TGR) - consequences from climate variability or from the TGR water modulation?

    NASA Astrophysics Data System (ADS)

    Wang, J.; Sheng, Y.; Tong, T. D.

    2012-12-01

    The central and lower reach of Yangtze Basin is the host of over 75% of Chinese freshwater lakes in area. Statuses of these lakes (e.g., size, level, and gradient) are closely associated with water levels and discharge from the Yangtze main stem and tributaries. This study presents a systematic diagnosis of the decadal (2000 - 2012) dynamics of lake inundation areas in this region, in response to local climate variability and upstream water level modulation from the Three Gorges Reservoir (TGR). We aim to investigate two overarching questions: i) How did inundation areas of the downstream lakes change before vs. after the initial TGR impounding (June, 2003)? ii) How much has water level modulation from the TGR altered the seasonality and annual trends of downstream lake areas in comparison to the contribution of natural precipitation? Existing literature on the interaction between TGR and downstream lakes was limited to individual lake cases and lacking contextual comparison with the surrounding tributary watersheds and lake systems. This study targeted 118 lakes larger than 25 km2 across the entire hydrologic watershed downstream from the TGR. Covering a total area of ~15,100 km2, these lakes constitute 80% of the total lake surface in the studied downstream basin. Based on their discriminant relationships with the Yangtze River (the main stem), these lakes were classified into three categories: (I) in the floodplain and freely connected to the Yangtze River; (II) in the floodplain but outflows to the Yangtze River artificially controlled (i.g., by sluice gates); and (III) beyond the floodplain. Lake areas in Classes I & II are considered to be influenced by the Yangtze River level. Daily-to-monthly areas of each studied lake was mapped using MODIS Terra imagery consecutively from February, 2000 to February, 2012. The combined lake inundation area from either Class I or II indicate a significant decline trend after the initial impounding event in late June, 2003

  15. Assessing the Risk of Phosphorus Loss and Identifying Critical Source Areas in the Chaohu Lake Watershed, China

    NASA Astrophysics Data System (ADS)

    Zhou, Huiping; Gao, Chao

    2011-11-01

    Agricultural nonpoint phosphorus (P) pollution is a primary cause of eutrophication in many freshwater systems. Identifying areas that are at high risk for P loss in a watershed and concentrating management efforts on these smaller sections is a more effective method for limiting P loss than implementing general strategies over a broad area. A modified P index scheme was used to assess the risk of P loss and identify critical source areas in the Chaohu Lake watershed on a regional scale. In the new P ranking scheme, soil P sorption index (PSI) and degree of P saturation (DPS) were introduced as source factors to represent the inherent ability of P transport in the soil-water interface. Distance from P sources to Chaohu Lake was also considered as a transport factor to take into account P degradation from source to the final receiving water. The ranking scheme was modified to use available data on the regional scale. P index calculation results showed high spatial variation of P loss risk in the Chaohu Lake watershed. The highest risk areas focused on the downstream parts of the main rivers that discharge into Chaohu Lake. The induction of new components into the P index calculation makes it possible to identify critical source areas of nonpoint P loss on a regional scale, thus allowing decision makers to implement best management practices (BMPs) in such a manner as to minimize P loss to sensitive watercourses.

  16. Scenario earthquake hazards for the Long Valley Caldera-Mono Lake area, east-central California

    USGS Publications Warehouse

    Chen, Rui; Branum, David M.; Wills, Chris J.; Hill, David P.

    2014-01-01

    As part of the U.S. Geological Survey’s (USGS) multi-hazards project in the Long Valley Caldera-Mono Lake area, the California Geological Survey (CGS) developed several earthquake scenarios and evaluated potential seismic hazards, including ground shaking, surface fault rupture, liquefaction, and landslide hazards associated with these earthquake scenarios. The results of these analyses can be useful in estimating the extent of potential damage and economic losses because of potential earthquakes and in preparing emergency response plans. The Long Valley Caldera-Mono Lake area has numerous active faults. Five of these faults or fault zones are considered capable of producing magnitude ≥6.7 earthquakes according to the Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2) developed by the 2007 Working Group of California Earthquake Probabilities (WGCEP) and the USGS National Seismic Hazard Mapping (NSHM) Program. These five faults are the Fish Slough, Hartley Springs, Hilton Creek, Mono Lake, and Round Valley Faults. CGS developed earthquake scenarios for these five faults in the study area and for the White Mountains Fault to the east of the study area. Earthquake scenarios are intended to depict the potential consequences of significant earthquakes. They are not necessarily the largest or most damaging earthquakes possible. Earthquake scenarios are both large enough and likely enough that emergency planners should consider them in regional emergency response plans. Earthquake scenarios presented here are based on fault geometry and activity data developed by the WGCEP, and are consistent with the 2008 Update of the United States National Seismic Hazard Maps (NSHM).For the Hilton Creek Fault, two alternative scenarios were developed in addition to the NSHM scenario to account for different opinions in how far north the fault extends into the Long Valley Caldera. For each scenario, ground motions were calculated using the current standard practice

  17. From Schistosomiasis Vector Habitats Identification to Human Transmission Risk Mapping, in the Poyang Lake Area (Jiangxi Province, PR China)

    NASA Astrophysics Data System (ADS)

    Marie, T.; Huber, C.; Yesou, H.

    2013-01-01

    Schistosomiasis (Bilharzias) is the most frequent disease after malaria in the world. This disease hit 200 million people, and threats 600 million people. In China, Schistosomiasis japonicum, a serious communicable parasitic disease, is endemic along the Yangtze River basin, including monsoon lakes. Risky transmission areas are conditioned by the S. japonicum vector’s presence and human activities and presence. On Poyang Lake, marshlands are the principal area of its development. The aim of this work is to answer : Where are areas suitable for vector’s disease development ? Where and what are the human activities the most exposed to disease transmission ? Where are urban areas with the higher level of disease transmission risk ? How data crossing can be useful for identification of areas with the higher transmission risk level ?

  18. Controlled-source electromagnetic survey at Soda Lakes geothermal area, Nevada

    SciTech Connect

    Stark, M.; Wilt, M.; Haught, J.R.; Goldstein, N.

    1980-07-01

    The EM-60 system, a large-moment frequency-domain electromagnetic loop prospecting system, was operated in the Soda Lakes geothermal area, Nevada. Thirteen stations were occupied at distances ranging from 0.5-3.0 km from two transmitter sites. These yielded four sounding curves--the normalized amplitudes and phases of the vertical and radial magnetic fields as a function of frequency--at each station. In addition, two polarization ellipse parameters, ellipticity and tilt angle, were calculated at each frequency. The data were interpreted by means of a least-squares inversion procedure which fits a layered resistivity model to the data. A three-layer structure is indicated, with a near-surface 20 ohm-m layer of 100-400 m thickness, a middle 2 ohm-m layer of approximately 1 km thickness, and a basement of greater than 10 ohm-m. The models indicate a northwesterly structural strike; the top and middle layers seem to thicken from northeast to southwest. The results agree quite well with previous results of dipole-dipole and magnetotelluric (MT) surveys. The EM-60 survey provided greater depth penetration (1 to 1.5 km) than dipole-dipole, but MT far surpassed both in its depth of exploration. One advantage of EM in this area is its ease and speed of operation. Another advantage, its relative insensitivity to lateral inhomogeneities, is not as pronounced here as it would be in areas of more complex geology.

  19. Atmospheric Mercury Transport Across Southern Lake Michigan: Influence from the Chicago/Gary Urban Area

    NASA Astrophysics Data System (ADS)

    Gratz, L. E.; Keeler, G. J.; Dvonch, J. T.

    2008-12-01

    The local and regional impacts of mercury emissions from major urban and industrial areas are critical to quantify in order to further understand mercury cycling in the environment. The Chicago/Gary urban area is one such location in which mercury emissions from industrial sources are significant and regional mercury transport needs to be further examined. Speciated atmospheric mercury was measured in Chicago, IL and Holland, MI from July to November 2007 to better characterize the impact of Chicago/Gary on southwest Michigan. Previous work under the 1994-1995 Lake Michigan Mass Balance Study (LMMBS) indicated that the highest levels of mercury deposition in southwest Michigan occurred with transport from the Chicago/Gary area, particularly with rapid transport where less mercury was deposited close to sources(1). However, at that time it was not possible to measure reactive gas phase mercury (RGM), a highly-soluble form of mercury in industrial emissions that is readily removed from the atmosphere. Since the LMMBS, the development of speciated mercury systems has made it possible to continuously monitor gaseous elemental mercury (Hg0), particulate mercury (HgP), and RGM. These measurements are useful for understanding atmospheric mercury chemistry and differentiating between local and regional source impacts due to the different behaviors of reactive and elemental mercury. Results from 2007 show that, on average, Hg0 and HgP were 1.5 times higher and RGM was 2 times higher in Chicago than in Holland. Mean mercury wet deposition was nearly 3 times higher in Chicago than in Holland. Meteorological analysis indicates that transport across the lake from Chicago/Gary occurred frequently during the study. Additional measurements of O3, SO2, meteorological parameters, event mercury and trace element precipitation samples, and modeled back-trajectories are used to discern regional transport events from local deposition and characterize the impact of the Chicago/Gary urban

  20. Yardangs in the Qaidam Basin, northwestern China: Distribution and morphology

    NASA Astrophysics Data System (ADS)

    Li, Jiyan; Dong, Zhibao; Qian, Guangqiang; Zhang, Zhengcai; Luo, Wanyin; Lu, Junfeng; Wang, Meng

    2016-03-01

    The northwestern Qaidam Basin exposes one of the largest and highest elevation yardang fields on Earth. The aim of the present study was to describe the distribution and morphology of these yardangs, and analyze the factors responsible for the distribution pattern of these aeolian landforms. The yardang fields are bounded by piedmont alluvial-diluvial fans from the mountain ranges surrounding the basin, except in the south, where they are bounded by dune fields, dry salt flats, lakes, and rivers. This distribution pattern can be attributed to regional tectogenesis and its corresponding environmental impacts. The morphology of the yardangs varies considerably in response to the diverse factors that control their formation and evolution. Long-ridge yardangs are mainly located in the northernmost part of the yardang field, and the long ridges are gradually dissected into smaller ridges in the downwind direction. Further downwind, the convergence of northerly and northwesterly winds and the effects of temporary runoff cause the ridges to gradually transition into mesa yardangs. Saw-toothed crests, and conical and pyramidal yardangs, occur in groups on folded brachyanticlinal structures. Typical whaleback yardangs are found in the southeast, at the northern margin of Dabuxun Lake. Morphological parameters vary among the yardang types. The orientation of the yardangs in the northernmost area is nearly N-S, with a transition towards NW-SE in the southernmost area in response to a change in the dominant wind direction that results from the orientations and positions of the mountain ranges that surround the basin.

  1. Predators and Prey: Jordan Lake State Recreation Area. An Environmental Education Learning Experience Designed for Grades K-3.

    ERIC Educational Resources Information Center

    Boswell, Henry, III; Stamm, Daniel K.

    This document provides hands-on environmental education activities for the classroom and the outdoor setting of Jordan Lake State Recreation Area. The activity packet, designed for grades K-3, meets curriculum objectives of the standard course of study established by the North Carolina Department of Public Instruction. It includes on-site…

  2. Guess What's for Dinner. Falls Lake State Recreation Area: An Environmental Education Learning Experience Designed for Grades 3-5.

    ERIC Educational Resources Information Center

    Donnelly, Paul; Martin, Merri

    This activity guide, developed to provide hands-on environmental education activities geared towards the Falls Lake State Recreation Area in North Carolina, is targeted for grades 3, 4, and 5 and meets curriculum objectives of the standard course of study established by the North Carolina Department of Public Instruction. Three types of activities…

  3. Ground-water exploration and test pumping in the Halma-Lake Bronson area Kittson County, Minnesota

    USGS Publications Warehouse

    Schiner, George R.

    1963-01-01

    Large quantities of water suitable for most industrial purposes are available in the Halma-Lake Bronson area. Yields of 1,000 to 2,000 gpm could probably be obtained from wells located by an adequate program of exploratory drilling and test pumping.

  4. Migrant Characteristics of a "Turnaround" Area: 1965-70 Immigration to a 45-County Subarea of the Upper Great Lakes.

    ERIC Educational Resources Information Center

    Voss, Paul R.; Fuguitt, Glenn V.

    Utilizing 1970 census data on a 45-county area in the northern Upper Great Lakes Region, the following questions were addressed: (1) In what ways do recent migrants to this nonmetropolitan region differ from those "nonmigrants" who resided in the region in both 1965 and 1970? (2) To what extent do the recent migrants from metropolitan counties…

  5. 77 FR 13074 - Opportunity for Designation in the Pocatello, ID; Evansville, IN; and Salt Lake City, UT Areas...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-05

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF AGRICULTURE Grain Inspection, Packers and Stockyards Administration Opportunity for Designation in the Pocatello, ID; Evansville, IN; and Salt Lake City, UT Areas; Request for Comments on the Official Agencies Servicing...

  6. Trace element mobility and transfer to vegetation within the Ethiopian Rift Valley lake areas.

    PubMed

    Kassaye, Yetneberk A; Skipperud, Lindis; Meland, Sondre; Dadebo, Elias; Einset, John; Salbu, Brit

    2012-10-26

    To evaluate critical trace element loads in native vegetation and calculate soil-to-plant transfer factors (TFs), 11 trace elements (Cr, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Pb and Mn) have been determined in leaves of 9 taxonomically verified naturally growing terrestrial plant species as well as in soil samples collected around 3 Ethiopian Rift Valley lakes (Koka, Ziway and Awassa). The Cr concentration in leaves of all the plant species was higher than the "normal" range, with the highest level (8.4 mg per kg dw) being observed in Acacia tortilis from the Lake Koka area. Caper species (Capparis fascicularis) and Ethiopian dogstooth grass (Cynodon aethiopicus) from Koka also contained exceptionally high levels of Cd (1 mg per kg dw) and Mo (32.8 mg per kg dw), respectively. Pb, As and Cu concentrations were low in the plant leaves from all sites. The low Cu level in important fodder plant species (Cynodon aethiopicus, Acacia tortilis and Opuntia ficus-indicus) implies potential deficiency in grazing and browsing animals. Compared to the Canadian environmental quality guideline and maximum allowable concentration in agricultural soils, the total soil trace element concentrations at the studied sites are safe for agricultural crop production. Enrichment factor was high for Zn in soils around Lakes Ziway and Awassa, resulting in moderate to high transfer of Zn to the studied plants. A six step sequential extraction procedure on the soils revealed a relatively high mobility of Cd, Se and Mn. Strong association of most trace elements with the redox sensitive fraction and mineral lattice was also confirmed by partial redundancy analysis. TF (mg per kg dw plants/mg per kg dw soil) values based on the total (TF(total)) and mobile fractions (TF(mobile)) of soil trace element concentrations varied widely among elements and plant species, with the averaged TF(total) and TF(mobile) values ranging from 0.01-2 and 1-60, respectively. Considering the mobile fraction in soils should

  7. Geologic map of the Bartlett Springs Fault Zone in the vicinity of Lake Pillsbury and adjacent areas of Mendocino, Lake, and Glenn Counties, California

    USGS Publications Warehouse

    Ohlin, Henry N.; McLaughlin, Robert J.; Moring, Barry C.; Sawyer, Thomas L.

    2010-01-01

    The Lake Pillsbury area lies in the eastern part of the northern California Coast Ranges, along the east side of the transform boundary between the Pacific and North American plates (fig. 1). The Bartlett Springs Fault Zone is a northwest-trending zone of faulting associated with this eastern part of the transform boundary. It is presently active, based on surface creep (Svarc and others, 2008), geomorphic expression, offset of Holocene units (Lienkaemper and Brown, 2009), and microseismicity (Bolt and Oakeshott, 1982; Dehlinger and Bolt, 1984; DePolo and Ohlin, 1984). Faults associated with the Bartlett Springs Fault Zone at Lake Pillsbury are steeply dipping and offset older low to steeply dipping faults separating folded and imbricated Mesozoic terranes of the Franciscan Complex and interleaved rocks of the Coast Range Ophiolite and Great Valley Sequence. Parts of this area were mapped in the late 1970s and 1980s by several investigators who were focused on structural relations in the Franciscan Complex (Lehman, 1978; Jordan, 1975; Layman, 1977; Etter, 1979). In the 1980s the U.S. Geological Survey (USGS) mapped a large part of the area as part of a mineral resource appraisal of two U.S. Forest Service Roadless areas. For evaluating mineral resource potential, the USGS mapping was published at a scale of 1:62,500 as a generalized geologic summary map without a topographic base (Ohlin and others, 1983; Ohlin and Spear, 1984). The previously unpublished mapping with topographic base is presented here at a scale of 1:30,000, compiled with other mapping in the vicinity of Lake Pillsbury. The mapping provides a geologic framework for ongoing investigations to evaluate potential earthquake hazards and structure of the Bartlett Springs Fault Zone. This geologic map includes part of Mendocino National Forest (the Elk Creek Roadless Area) in Mendocino, Glenn, and Lake Counties and is traversed by several U.S. Forest Service Routes, including M1 and M6 (fig. 2). The study

  8. Tree rings and environmental change during deglaciation in the N. American Great Lakes area

    NASA Astrophysics Data System (ADS)

    Leavitt, S. W.; Panyushkina, I. P.

    2010-12-01

    Greenland ice-core proxies give a high-resolution perspective on the remarkable climate variability since the last full-glacial period, but high-resolution tree-ring records could provide valuable added insight into this variability and its manifestations in terrestrial settings. Only a single oak/pine tree-ring chronology from Europe extends from the present to beyond 10,000 years ago, so inferring high-resolution mid-N. American environmental variability during this period is a particularly challenging but worthwhile objective, because trajectories of human and mega-fauna populations are likely linked to this variability, and some of the abrupt hemispheric- to global-scale climate events may have even been triggered in this region. Fortunately, the geologic circumstances of this post-glacial period have been favorable to preservation of wood in the time frame from 8000 to 14,000 years ago. In an ongoing project originating in 2002, we have been slowly accumulating wood samples from around the Great Lakes area variously preserved in glacial till, sands of alluvial and lacustrine origin, peat deposits, and submerged in lakes. In addition to contributing an expanding set of “floating” tree-ring chronologies for discrete time intervals within the 6000-year period, some coeval chronologies are from different locations so spatial variability can be gleaned. This presentation reports on the progress of this project with respect to sites, chronologies, ring-width and isotope analysis, patterns of change in variability through time, and comparison with modern trees. Among the most notable discoveries thus far has been a Younger Dryas event-age forest, whose unusual history is chronicled through the tree-ring micro-features and measurements.

  9. The Center for Talent Development at Northwestern University

    ERIC Educational Resources Information Center

    Olszewski-Kubilius, Paula

    2004-01-01

    During the summer and on weekends, it is not unusual to see many children, the youngest holding their parents' hands, walking to classes amongst the beautiful landscaping and old buildings of Northwestern University on Lake Michigan's shores in Evanston, Illinois. The Center for Talent Development (CTD) has been offering services and programs to…

  10. PAH distributions in sediments in the oil sands monitoring area and western Lake Athabasca: Concentration, composition and diagnostic ratios.

    PubMed

    Evans, Marlene; Davies, Martin; Janzen, Kim; Muir, Derek; Hazewinkel, Rod; Kirk, Jane; de Boer, Dirk

    2016-06-01

    Oil sands activities north of Fort McMurray, Alberta, have intensified in recent years with a concomitant debate as to their environmental impacts. The Regional Aquatics Monitoring Program and its successor, the Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring (JOSM), are the primary aquatic programs monitoring this industry. Here we examine sediment data (collected by Ekman grabs) to investigate trends and sources of polycyclic aromatic hydrocarbons (PAHs), supplementing these data with sediment core studies. Total PAH (ΣPAH) concentrations were highest at Shipyard Lake (6038 ± 2679 ng/g) in the development center and lower at Isadore's Lake (1660 ± 777 ng/g) to the north; both lakes are in the Athabasca River Valley and lie below the developments. ΣPAH concentrations were lower (622-930 ng/g) in upland lakes (Kearl, McClelland) located further away from the developments. ΣPAH concentrations increased at Shipyard Lake (2001-2014) and the Ells River mouth (1998-2014) but decreased in nearshore areas at Kearl Lake (2001-2014) and a Muskeg River (2000-2014) site. Over the longer term, ΣPAH concentrations increased in Kearl (1934-2012) and Sharkbite (1928-2010) Lakes. Further (200 km) downstream in the Athabasca River delta, ΣPAH concentrations (1029 ± 671 ng/g) increased (1999-2014) when %sands were included in the regression model; however, 50 km to the east, concentrations declined (1926-2009) in Lake Athabasca. Ten diagnostic ratios based on anthracene, phenanthrene, fluoranthene, pyrene, benz[a]anthracene, chrysene, indeno[123-cd]pyrene, dibenz[a,h]anthracene, dibenzothiophene and retene were examined to infer spatial and temporal trends in PAH sources (e.g., combustion versus petrogenic) and weathering. There was some evidence of increasing contributions of unprocessed oil sands and bitumen dust to Shipyard, Sharkbite, and Isadore's Lakes and increased combustion sources in the Athabasca River delta. Some CCME interim

  11. Occurrence of zebra mussels in near-shore areas of western Lake Erie

    USGS Publications Warehouse

    Custer, Christine M.; Custer, T.W.

    1997-01-01

    Zebra mussels (Dreissena polymorpha) invaded the Great Lakes in the mid-1980s and quickly reached high densities. The objective of this study was to determine current consumption of zebra mussels by waterfowl in the Great Lakes region. Feeding Lesser Scaups (Aythya affinis), Greater Scaups (A. marila), Canvasbacks (A. valisineria), Redheads (A. americana), Buffleheads (Bucephala albeola) and Common Goldeneyes (B. clangula) were collected in western Lake Erie and in Lake St. Clair between fall and spring, 1992-1993 to determine food habits. All 10 Redheads, 97% of Lesser Scaups, 83% of Goldeneyes, 60% of Buffleheads and 9% of Canvasbacks contained one or more zebra mussels in their upper gastrointestinal tracts. The aggregate percent of zebra mussels in the diet of Lesser Scaups was higher in Lake Erie (98.6%) than in Lake St. Clair (54.4%). Zebra mussels, (aggregate percent) dominated the diet of Common Goldeneyes (79.2%) but not in Buffleheads (23.5%), Redheads (21%) or Canvasbacks (9%). Lesser Scaups from Lake Erie fed on larger zebra mussels ( = 10.7 i?? 0.66 mm SE) than did Lesser Scaups from Lake St. Clair ( = 4.4 i?? 0.22 mm). Lesser Scaups, Buffleheads and Common Goldeneyes from Lake Erie consumed zebra mussels of similar size.

  12. Geological and geochemical investigations of uranium occurrences in the Arrastre Lake area of the Medicine Bow Mountains, Wyoming

    USGS Publications Warehouse

    Miller, W. Roger; Houston, R.S.; Karlstrom, K.E.; Hopkins, D.M.; Ficklin, W.H.

    1977-01-01

    Metasedimentary rocks of Precambrian X age in and near the Snowy Range wilderness study area of southeastern Wyoming are lithologically and chronologically similar to those on the north shore of Lake Huron in Canada. The rocks in Canada contain major deposits of uranium in quartz-pebble conglomerates near the base of the metasedimentary sequence. Similar conglomerates in the Deep Lake Formation in the Medicine Bow Mountains of southeastern Wyoming are slightly radioactive and may contain deposits of uranium and other valuable heavy metals. During the summer of 1976, a geological and geochemical pilot study was conducted in the vicinity of Arrastre Lake in the Medicine Bow Mountains to determine the most effective exploration methods for evaluating the uranium potential of the Snowy Range wilderness study area. The area around Arrastre Lake was selected because of the presence of a radioactive lens within a quartz-pebble conglomerate of the Deep Lake Formation. The results of the survey indicate possible uranium mineralization in the subsurface rocks of this formation. The radon content of the dilute waters of the area is much higher than can be accounted for by the uranium content of the surface rocks. Two sources for the high content of the radon are possible. In either case, the high values of radon obtained in this study are a positive indication of uranium mineralization in the subsurface rocks. The determination of the radon content of water samples is the recommended geochemical technique for uranium exploration in the area. The determination of uranium in water and in organic-rich bog material is also recommended.

  13. Intense methane ebullition from open water area of a shallow peatland lake on the eastern Tibetan Plateau.

    PubMed

    Zhu, Dan; Wu, Yan; Chen, Huai; He, Yixin; Wu, Ning

    2016-01-15

    Methane fluxes from a shallow peatland lake (3450 m a.s.l., 1.6 km(2) in area, maximum depth <1m) on eastern Tibetan Plateau were measured with floating chamber method during May to August, 2009. The overall average of methane emission rate during the study period was 34.71±29.15 mg CH4 m(-2) h(-1). The occurrence of ebullition among the overall methane flux from Lake Medo was about 74%. The average rate of ebullition was 32.45±28.31 mg CH4 m(-2) h(-1), which accounted for 93% of the overall average of methane emission. Significant seasonal variation was found for occurrence (P<0.05) and rate (P<0.01) of ebullition, both peaking synchronously in mid-summer. Both the occurrence and rate of ebullition were found positively related to sediment temperature but negatively related to lake water depth. The high methane production in the lake sediment was likely fueled by organic carbon loaded from surrounding peatlands to the lake. The shallowness of the water column could be another important favorable factor for methane-containing bubble formation in the sediment and their transportation to the atmosphere. The methane ebullition must have been enhanced by the low atmospheric pressure (ca. 672 hPa) in the high-altitude environment. For a better understanding on the mechanism of methane emission from alpine lakes, more lakes on the Tibetan Plateau should be studied in the future for their methane ebullition. PMID:26519567

  14. A study on the levels of radioactivity in fish samples from the experimental lakes area in Ontario, Canada.

    PubMed

    Chen, Jing; Rennie, Michael D; Sadi, Baki; Zhang, Weihua; St-Amant, Nadereh

    2016-03-01

    To better understand background radiation levels in country foods, a total of 125 fish samples were collected from three lakes (Lake 226, Lake 302 and Lake 305) in the Experimental Lakes Area (ELA) in Ontario of Canada during the summer of 2014. Concentrations of naturally occurring radionuclides ((226)Ra, (210)Pb and (210)Po) as well as anthropogenic radionuclides ((134)Cs and (137)Cs) were measured. This study confirmed that (210)Po is the dominant contributor to radiation doses resulting from fish consumption. While concentrations of (210)Pb and (226)Ra were below conventional detection limits, (210)Po was measured in almost all fish samples collected from the ELA. The average concentration was about 1.5 Bq/kg fresh weight (fw). None of the fish samples analysed in this study contained any detectable levels of (134)Cs. An average (137)Cs level of 6.1 Bq/kg fw was observed in freshwater fishes harvested in the ELA, almost twice that of samples measured in the National Capital Region of Canada in 2014 and more than 20 times higher than the levels observed in marine fish harvested from the Canadian west coast in 2013 and 2014. However, it is important to note that the concentrations of (137)Cs in fish samples from these inland lakes are considered very low from a radiological protection perspective. The resulting radiation dose for people from fish consumption would be a very small fraction of the annual dose from exposure to natural background radiation in Canada. The results indicate that fishes from inland lakes do not pose a radiological health concern. PMID:26803403

  15. Availability and quality of ground water in the Lake George area, southeastern Park County, Colorado

    USGS Publications Warehouse

    Goddard, Kimball E.

    1978-01-01

    Water for domestic use in the Lake George area, Colo., is produced from four aquifers. Two of the aquifers, fractured-cyrstalline and volcanic rocks, have a water table ranging from 10 to 100 feet below land surface and well yields range from 0.08 to 6 gallons per minute. The consolidated sedimentary-rock and unconsolidated-alluvial aquifers have a water table ranging from near land surface to 60 feet below land surface and well yields range from 2 to 50 gallons per minute. The aquifers generally contain calcium bicarbonate water with concentrations of dissolved solids ranging from 101 to 636 milligrams per liter. In some areas, concentrations of iron as much as 18,000 micrograms per liter and concentrations of fluoride as much as 5.6 milligrams per liter affect suitability for domestic use. Chemical degradation of ground water has occurred in 18 of the 35 wells and in the 1 spring that were sampled. Bacterial contamination was found in water from six wells. (Woodard-USGS)

  16. The transmission of Schistosoma haematobium in an area of Lake Province, Tanganyika

    PubMed Central

    Webbe, G.

    1962-01-01

    This paper records the results of detailed studies carried out over a two-year period on the transmission of Schistosoma haematobium in an area of Lake Province, Tanganyika. The ecology of a variety of snail habitats is described; and data on the biology of the principal molluscan host (Bulinus (Physopsis) nasutus productus), on seasonal fluctuations in its population density and associated cercarial infection rates, on its response to desiccation and on other aspects of population dynamics are presented and discussed. Taking into consideration the seasonal fluctuation in snail numbers which occurs in the area and the snails' capacity to survive desiccation, it is considered that a substantial reduction in transmission of S. haematobium might be effected by application of a molluscicide timed so as to lower the population density before aestivation begins, followed by a second treatment when the habitats have been refilled by rainfall to reduce yet further the population that has survived the first treatment and subsequent desiccation. It is also suggested that a combination of methods directed against two stages in the schistosome life-cycle—the snail and the miracidium—by application of molluscicides and treatment of infected persons might be more efficacious than an attempt merely to reduce snail density and alter the population structure. PMID:14005428

  17. Thermally Released Arsenic in Porewater from Sediments in the Cold Lake Area of Alberta, Canada.

    PubMed

    Javed, Muhammad Babar; Siddique, Tariq

    2016-03-01

    Elevated arsenic (As) in aquifers in close proximity to in situ oil sands extraction in the Cold Lake area, Alberta, Canada is attributed to high temperature steam (~200 °C) injected into oil sands deposits to liquefy bitumen. Heat propagated from hot injection wells alters physicochemical properties of the surrounding sediments and associated porewater. Seven sediments from four different cores drilled up to ~300 m depth collected from different locations in the area were used to study the thermal effect (~200 °C) on As distribution in the sediments and its release into porewater. Sediments were moistened with synthetic aquifer or deionized water according to the moisture regimes present in aquitard, aquifer and fractured zones. Heat application greatly released As in the porewater (500-5200 and 1200-6600 μg L(-1)) from aquifer and fractured sediments, respectively. Mass balance of As chemical fractionation showed that ~89-100% of As in porewater was released from exchangeable and specifically adsorbed As in the sediments. Heat application also altered As distribution in the sediments releasing As from exchange surfaces and amorphous Fe oxides to soluble As fraction. The results provide great insight into As release mechanisms warranting development of strategies to mitigate groundwater As contamination during industrial operation. PMID:26839972

  18. Possible Climatic Signal Recorded by Alkenone Distributions in Sediments from Freshwater and Saline Lakes on the Skarvsnes and Skallen Areas, Antarctica

    NASA Astrophysics Data System (ADS)

    Sawada, K.; Takeda, M.; Takano, Y.

    2014-12-01

    The distribution of long-chain (C37 - C39) alkenones in marine sediment has been well documented to record paleo-sea surface temperatures. The alkenones were also found in sediments of terrestrial saline lakes, and recently the calibrations of alkenone unsaturation indices - temperature have been established in continental areas. Furthermore, these biomarkers have been identified in lacustrine sediments on high-latitudinal terrestrial areas such as Greenland and Antarctica. In the present study, the alkenones were identified in the lacustrine sediment cores in freshwater (Lake Naga-ike) and saline lakes (Lake Suribati and Lake Funazoko) on the Skarvsnes, and a saline lake (Lake Skallen Oh-ike) on the Skallen, Antarctica. Here, we report that the alkenone distribution in the Antarctic lakes was examined as paleotemperature proxy. C37-C38 Tetra- and tri-unsaturated alkenones and C37 tetra- and tri-unsaturated alkenoates are identified in all sediment samples. The C37 di-unsaturated (C37:2) alkenones can be identified in sediments of surface layers (0-15 cm) of Lake Naga-ike and layers of 160-190 cm depth, in which age is ca. 3000 years BP by 14C dating, in Lake Skallen Ohike, and alkenone unsaturation index (UK37) is analyzed from these sediments. By using a calibration obtained from a culture strain Chrysotila lamellosa as reported by Nakamura et al. (2014), paleotemperatures are calculated to be 9.2-15ºC in surface sediments of Lake Naga-ike and 6.8-8.6ºC in Lake Skallen Oh-ike, respectively. The estimated temperatures are concordant with summer temperature of lake waters observed in Lake Naga-ike. Also, the highest concentrations of the alkenones and alkenoates are observed in deeper (older) sediment layers from Lake Naga-ikes, which has not been connected the ocean and intruded sea water. This implies that the alkenones are originated from indigenous biological organism(s) in Antarctic lake water. The class distributions (unsaturation ratios) of alkenones

  19. A model to locate potential areas for lake sturgeon spawning habitat construction in the St. Clair–Detroit River System

    USGS Publications Warehouse

    Bennion, David; Manny, Bruce A.

    2014-01-01

    In response to a need for objective scientific information that could be used to help remediate loss of fish spawning habitat in the St. Clair River and Detroit River International Areas of Concern, this paper summarizes a large-scale geographic mapping investigation. Our study integrates data on two variables that many riverine fishes respond to in selecting where to spawn in these waters (water flow velocity and water depth) with available maps of the St. Clair–Detroit River System (SC–DRS). Our objectives were to locate and map these two physical components of fish habitat in the St. Clair and Detroit rivers and Lake St. Clair using a geographic information system (GIS) and to identify where, theoretically, fish spawning habitat could be remediated in these rivers. The target fish species to which this model applies is lake sturgeon (Acipenser fulvescens), but spawning reefs constructed for lake sturgeon in this system have been used for spawning by 17 species of fish. Our analysis revealed areas in each river that possessed suitable water velocity and depth for fish spawning and therefore could theoretically be remediated by the addition of rock-rubble substrate like that used at two previously remediated sites in the Detroit River at Belle Isle and Fighting Island. Results of our analysis revealed that only 3% of the total area of the SC–DRS possesses the necessary combination of water depth and high flow velocity to be indicated by the model as potential spawning habitat for lake sturgeon.

  20. Lake fish as the main contributor of internal dose to lakeshore residents in the Chernobyl contaminated area.

    PubMed

    Travnikova, I G; Bazjukin, A N; Bruk, G Ja; Shutov, V N; Balonov, M I; Skuterud, L; Mehli, H; Strand, P

    2004-01-01

    Two field expeditions in 1996 studied 137Cs intake patterns and its content in the bodies of adult residents from the village Kozhany in the Bryansk region, Russia, located on the shore of a drainless peat lake in an area subjected to significant radioactive contamination after the 1986 Chernobyl accident. The 137Cs contents in lake water and fish were two orders of magnitude greater than in local rivers and flow-through lakes, 10 years after Chernobyl radioactive contamination, and remain stable. The 137Cs content in lake fish and a mixture of forest mushrooms was between approximately 10-20 kBq/kg, which exceeded the temporary Russian permissible levels for these products by a factor of 20-40. Consumption of lake fish gave the main contribution to internal doses (40-50%) for Kozhany village inhabitants Simple countermeasures, such as Prussian blue doses for dairy cows and pre-boiling mushrooms and fish before cooking, halved the 137Cs internal dose to inhabitants, even 10 years after the radioactive fallout. PMID:15297041

  1. Predation on lake whitefish eggs by longnose suckers

    USGS Publications Warehouse

    Nester, Robert T.; Poe, Thomas P.

    1984-01-01

    In November 1981, we observed intense predation on lake whitefish (Coregonus clupeaformis) eggs by longnose suckers (Catostomus catostomus) on lake whitefish spawning grounds in northwestern Lake Huron. Since longnose suckers commonly frequent the same habitat used by spawning lake whitefish, there exists the potential for high losses of eggs due to sucker predation.

  2. Use of thermal inertia determined by HCMM to predict nocturnal cold prone areas in Florida. [The Everglades agricultural area, Lake Okeechobee, and the Suwanee River basin

    NASA Technical Reports Server (NTRS)

    Allen, L. H., Jr. (Principal Investigator); Chen, E.; Martsolf, J. D.; Jones, P. H.

    1981-01-01

    Transparencies, prints, and computer compatible tapes of temperature differential and thermal inertia for the winter of 1978 to 1979 were obtained. Thermal inertial differences in the South Florida depicted include: drained organic soils of the Everglades agricultural area, undrained organic soils of the managed water conservation areas of the South Florida water management district, the urbanized area around Miami, Lake Okeechobee, and the mineral soil west of the Everglades agricultural area. The range of wetlands and uplands conditions within the Suwanee River basin was also identified. It is shown that the combination of wetlands uplands surface features of Florida yield a wide range of surface temperatures related to wetness of the surface features.

  3. 40 CFR 81.126 - Northwestern Oklahoma Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Northwestern Oklahoma Intrastate Air... Air Quality Control Regions § 81.126 Northwestern Oklahoma Intrastate Air Quality Control Region. The Northwestern Oklahoma Intrastate Air Quality Control Region consists of the territorial area encompassed by...

  4. 40 CFR 81.126 - Northwestern Oklahoma Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Northwestern Oklahoma Intrastate Air... Air Quality Control Regions § 81.126 Northwestern Oklahoma Intrastate Air Quality Control Region. The Northwestern Oklahoma Intrastate Air Quality Control Region consists of the territorial area encompassed by...

  5. 40 CFR 81.126 - Northwestern Oklahoma Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Northwestern Oklahoma Intrastate Air... Air Quality Control Regions § 81.126 Northwestern Oklahoma Intrastate Air Quality Control Region. The Northwestern Oklahoma Intrastate Air Quality Control Region consists of the territorial area encompassed by...

  6. 40 CFR 81.126 - Northwestern Oklahoma Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Northwestern Oklahoma Intrastate Air... Air Quality Control Regions § 81.126 Northwestern Oklahoma Intrastate Air Quality Control Region. The Northwestern Oklahoma Intrastate Air Quality Control Region consists of the territorial area encompassed by...

  7. 40 CFR 81.126 - Northwestern Oklahoma Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 18 2014-07-01 2014-07-01 false Northwestern Oklahoma Intrastate Air... Air Quality Control Regions § 81.126 Northwestern Oklahoma Intrastate Air Quality Control Region. The Northwestern Oklahoma Intrastate Air Quality Control Region consists of the territorial area encompassed by...

  8. Review of Apanteles sensu stricto (Hymenoptera, Braconidae, Microgastrinae) from Area de Conservación Guanacaste, northwestern Costa Rica, with keys to all described species from Mesoamerica

    PubMed Central

    Fernández-Triana, Jose L.; Whitfield, James B.; Rodriguez, Josephine J.; Smith, M. Alex; Janzen, Daniel H.; Hallwachs, Winnie D.; Hajibabaei, Mehrdad; Burns, John M.; Solis, M. Alma; Brown, John; Cardinal, Sophie; Goulet, Henri; Hebert, Paul D. N.

    2014-01-01

    Abstract More than half a million specimens of wild-caught Lepidoptera caterpillars have been reared for their parasitoids, identified, and DNA barcoded over a period of 34 years (and ongoing) from Area de Conservación de Guanacaste (ACG), northwestern Costa Rica. This provides the world’s best location-based dataset for studying the taxonomy and host relationships of caterpillar parasitoids. Among Hymenoptera, Microgastrinae (Braconidae) is the most diverse and commonly encountered parasitoid subfamily, with many hundreds of species delineated to date, almost all undescribed. Here, we reassess the limits of the genus Apanteles sensu stricto, describe 186 new species from 3,200+ parasitized caterpillars of hundreds of ACG Lepidoptera species, and provide keys to all 205 described Apanteles from Mesoamerica – including 19 previously described species in addition to the new species. The Mesoamerican Apanteles are assigned to 32 species-groups, all but two of which are newly defined. Taxonomic keys are presented in two formats: traditional dichotomous print versions and links to electronic interactive versions (software Lucid 3.5). Numerous illustrations, computer-generated descriptions, distributional information, wasp biology, and DNA barcodes (where available) are presented for every species. All morphological terms are detailed and linked to the Hymenoptera Anatomy Ontology website. DNA barcodes (a standard fragment of the cytochrome c oxidase I (COI) mitochondrial gene), information on wasp biology (host records, solitary/gregariousness of wasp larvae), ratios of morphological features, and wasp microecological distributions were used to help clarify boundaries between morphologically cryptic species within species-complexes. Because of the high accuracy of host identification for about 80% of the wasp species studied, it was possible to analyze host relationships at a regional level. The ACG species of Apanteles attack mainly species of Hesperiidae

  9. Monitoring Changes in Water Resources Systems Using High Resolution Satellite Observations: Application to Lake Urmia

    NASA Astrophysics Data System (ADS)

    Norouzi, H.; AghaKouchak, A.; Madani, K.; Mirchi, A.; Farahmand, A.; Conway, C.

    2013-12-01

    Lake Urmia with its unique ecosystem in northwestern Iran is the second largest saltwater lake in the world. It is home of more than 300 species of birds, reptiles, and mammals with high salinity level of more than 300 g/l. In recent years, a significant water retreat has occurred in this lake. In this study, we tried to monitor the desiccation of the lake over more than four decades using remote sensing observations. Multi-spectral high-resolution LandSat images of the Lake Urmia region from 1972 to 2012 were acquired to derive the lake area. The composite maps of the lake were created, and a Bayesian Maximum Likelihood classification technique was used to classify land and water in the composite maps. The time series of the lake area reveals that it has shrunk by more than 40% in the past ten years. Moreover, water budget related components such as precipitation, soil moisture, and drought indices from remote sensing of the lake basin were utilized to investigate if droughts or climate change are the primary driving forces behind this phenomenon. These analyses show that the retreat of the lake is not related to droughts or global climate change as it has survived several drought events before year 2000. Similar analyses conducted on Lake Van located about 400 km west of Lake Urmia with very similar climate pattern revealed no significant areal change despite the lake's exposure to similar drought events. These results raise serious concern about the destructive role of unbridled development coupled with supply-oriented water management scheme driven by a classic upstream-downstream competition for water in the Lake Urmia region. There is an urgent need to investigate sustainable restoration initiatives for Lake Urmia in order to prevent an environmental disaster comparable to catastrophic death of Aral Sea.

  10. An appraisal of potential water salvage in the Lake McMillan Delta area, Eddy County, New Mexico

    USGS Publications Warehouse

    Cox, Edward Riley; Havens, John S.

    1974-01-01

    The Lake McMillan delta area is located between Artesia and Lake McMillan on the Pecos River in Eddy County, N. Mex. Alluvium, which is more than 200 feet thick in places, is the principal water-bearing formation and is part of the 'shallow aquifer' of the Roswell basin. Recharge to the shallow aquifer is by infiltration from the Pecos River, by irrigation water, by precipitation, and by ground water that moves into the area. Discharge from the shallow aquifer is by wells, by transpiration from phreatophytes, and by evaporation from swampy areas. Saltcedar growth in the area increased during the study period from about 13,700 acres in 1952 to about 17,100 acres in 1960, a 25-percent increase. Most of this increase was in the areal-density range of zero to 30 percent. The estimated average transpiration of phreatophytes in the Artesia to Lake McMillan reach is about 29,000 acre-feet of water per year from ground-water sources. In the reach from Artesia to the Rio Pefiasco, where the regional water table is above the Pecos River, saltcedar eradication might salvage from 10,000 to 20,000 acre-feet of water per year for use downstream. From the Rio Pefiasco to Lake McMillan the river is perched above the water table; therefore, elimination of the saltcedar probably would not increase flow in the river, nor would drains be effective. Clearing in this reach, however, might increase the flow at Major Johnson Springs below Lake McMillan. Floodways through this reach would eliminate some evapotranspiration but might increase the amount of sediment deposited by floodwaters in bake McMillan.

  11. Analysis and simulation of ground-water flow in Lake Wales Ridge and adjacent areas of central Florida

    USGS Publications Warehouse

    Yobbi, Dann K.

    1996-01-01

    The Lake Wales Ridge is an uplands recharge area in central Florida that contains many sinkhole lakes. Below-normal rainfall and increased pumping of ground water have resulted in declines both in ground-water levels and in the water levels of many of the ridge lakes. A digital flow model was developed for a 3,526 square-mile area to help understand the current (1990) ground-water flow system and its response to future ground-water withdrawals. The ground-water flow system in the Lake Wales Ridge and adjacent area of central Florida consists of a sequence of sedimentary aquifers and confining units. The uppermost water-bearing unit of the study area is the surficial aquifer. This aquifer is generally unconfined and is composed primarily of clastic deposits. The surficial aquifer is underlain by the confined intermediate aquifer and confining units which consists of up to three water-bearing units composed of interbedded clastics and carbonate rocks. The lowermost unit of the ground- water flow system, the confined Upper Floridan aquifer, consists of a thick, hydraulically connected sequence of carbonate rocks. The Upper Floridan aquifer is about 1,200 to 1,400 feet thick and is the primary source for ground-water withdrawals in the study area. The generalized ground-water flow system of the Lake Wales Ridge is that water moves downward from the surficial aquifer to the intermediate aquifer and the Upper Floridan aquifer in the central area, primarily under the ridges, with minor amounts of water flow under the flatlands. The water flows laterally away fromn the central area, downgradient to discharge areas to the west, east, and south, and locally along valleys of major streams. Upward leakage occurs along valleys of major streams. The model was initially calibrated to the steady-state conditions representing September 1989. The resulting calibrated hydrologic parameters were then tested by simulating transient conditions for the period October 1989 through 1990. A

  12. Response of lake chemistry to atmospheric deposition and climate in selected Class I wilderness areas in the western United States, 1993-2009

    USGS Publications Warehouse

    Mast, M. Alisa

    2011-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Department of Agriculture Forest Service, Air Resource Management, conducted a study to evaluate long-term trends in lake-water chemistry for 64 high-elevation lakes in selected Class I wilderness areas in Colorado, Idaho, Utah, and Wyoming during 1993 to 2009. Understanding how and why lake chemistry is changing in mountain areas is essential for effectively managing and protecting high-elevation aquatic ecosystems. Trends in emissions, atmospheric deposition, and climate variables (air temperature and precipitation amount) were evaluated over a similar period of record. A main objective of the study was to determine if changes in atmospheric deposition of contaminants in the Rocky Mountain region have resulted in measurable changes in the chemistry of high-elevation lakes. A second objective was to investigate linkages between lake chemistry and air temperature and precipitation to improve understanding of the sensitivity of mountain lakes to climate variability.

  13. GREAT LAKES BEACH CLOSURES: USING SATELLITE IMAGES TO IDENTIFY AREAS AT RISK

    EPA Science Inventory

    Are people getting sick from swimming at Great Lakes beaches? Some are. According to the Centers for Disease Control and Prevention, swimmers are experiencing an increase in bacterial borne illnesses from swimming at many popular Great Lakes beaches. The beaches in the Great Lak...

  14. First evidence of successful natural reproduction by planted lake trout in Lake Huron

    USGS Publications Warehouse

    Nester, Robert T.; Poe, Thomas P.

    1984-01-01

    Twenty-two lake trout (Salvelinus namaycush) swim-up fry, 24-27 mm long, were captured with emergent fry traps and a tow net in northwestern Lake Huron on a small nearshore reef off Alpena, Michigan, between May 10 and June 1, 1982. These catches represent the first evidence of successful production of swim-up fry by planted, hatchery-reared lake trout in Lake Huron since the lake trout rehabilitation program began in 1973.

  15. SESPE-FRAZIER, DIABLO, MATILIJA, DRY LAKES, SAWMILL-BADLANDS, CUYAMA, ANTIMONY, AND QUATAL ROADLESS AREAS, CALIFORNIA.

    USGS Publications Warehouse

    Frizzell, Virgil A., Jr.; Hale, William N.

    1984-01-01

    The study area, consisting of the Sespe-Frazier, Diablo, Matilija, Dry Lakes, Sawmill-Badlands, Cuyama, Antimony, and Quatal Roadless Areas, occupies about 872 sq mi in the Los Padres National Forest, California. Studies indicate that the Sespe-Frazier Roadless Area contains demonstrated resources of gold, gypsum, phosphate and bentonite; deposits in the Cuyama Roadless Area have demonstrated resources of gypsum; mines in the Antimony Roadless Area have demonstrated resources of antimony, gold, silver, and marble; and the Quatal Roadless Area has demonstrated resources of bentonite. The Sespe-Frazier Roadless Area has substantiated potential for geothermal resources suitable for direct-heat purposes, probable and substantiated potential for oil and gas resources, and probable potential for gold resources. Small areas of probable resource potential for antimony and gold were identified in Antimony Roadless Area.

  16. Freshwater bacterioplankton richness in oligotrophic lakes depends on nutrient availability rather than on species–area relationships

    PubMed Central

    Logue, Jürg Brendan; Langenheder, Silke; Andersson, Anders F; Bertilsson, Stefan; Drakare, Stina; Lanzén, Anders; Lindström, Eva S

    2012-01-01

    A central goal in ecology is to grasp the mechanisms that underlie and maintain biodiversity and patterns in its spatial distribution can provide clues about those mechanisms. Here, we investigated what might determine the bacterioplankton richness (BR) in lakes by means of 454 pyrosequencing of the 16S rRNA gene. We further provide a BR estimate based upon a sampling depth and accuracy, which, to our knowledge, are unsurpassed for freshwater bacterioplankton communities. Our examination of 22 669 sequences per lake showed that freshwater BR in fourteen nutrient-poor lakes was positively influenced by nutrient availability. Our study is, thus, consistent with the finding that the supply of available nutrients is a major driver of species richness; a pattern that may well be universally valid to the world of both micro- and macro-organisms. We, furthermore, observed that BR increased with elevated landscape position, most likely as a consequence of differences in nutrient availability. Finally, BR decreased with increasing lake and catchment area that is negative species–area relationships (SARs) were recorded; a finding that re-opens the debate about whether positive SARs can indeed be found in the microbial world and whether positive SARs can in fact be pronounced as one of the few ‘laws' in ecology. PMID:22170419

  17. Analysis of modern and Pleistocene hydrologic exchange between Saginaw Bay (Lake Huron) and the Saginaw Lowlands area

    USGS Publications Warehouse

    Hoaglund, J. R., III; Kolak, J.J.; Long, D.T.; Larson, G.J.

    2004-01-01

    Two numerical models, one simulating present groundwater flow conditions and one simulating ice-induced hydraulic loading from the Port Huron ice advance, were used to characterize both modern and Pleistocene groundwater exchange between the Michigan Basin and near-surface water systems of Saginaw Bay (Lake Huron) and the surrounding Saginaw Lowlands area. These models were further used to constrain the origin of saline, isotopically light groundwater, and porewater from the study area. Output from the groundwater-flow model indicates that, at present conditions, head in the Marshall aquifer beneath Saginaw Bay exceeds the modern lake elevation by as much as 21 m. Despite this potential for flow, simulated groundwater discharge through the Saginaw Bay floor constitutes only 0.028 m3 s-1 (???1 cfs). Bedrock lithology appears to regulate the rate of groundwater discharge, as the portion of the Saginaw Bay floor underlain by the Michigan confining unit exhibits an order of magnitude lower flux than the portion underlain by the Saginaw aquifer. The calculated shoreline discharge of groundwater to Saginaw Bay is also relatively small (1.13 m3 s-1 or ???40 cfs) because of low gradients across the Saginaw Lowlands area and the low hydraulic conductivities of lodgement tills and glacial-lake clays surrounding the bay. In contrast to the present groundwater flow conditions, the Port Huron ice-induced hydraulic-loading model generates a groundwater-flow reversal that is localized to the region of a Pleistocene ice sheet and proglacial lake. This area of reversed vertical gradient is largely commensurate with the distribution of isotopically light groundwater presently found in the study area. Mixing scenarios, constrained by chloride concentrations and ??18O values in porewater samples, demonstrate that a mixing event involving subglacial recharge could have produced the groundwater chemistry currently observed in the Saginaw Lowlands area. The combination of models and

  18. ICCLP: An Inexact Chance-Constrained Linear Programming Model for Land-Use Management of Lake Areas in Urban Fringes

    NASA Astrophysics Data System (ADS)

    Liu, Yong; Qin, Xiaosheng; Guo, Huaicheng; Zhou, Feng; Wang, Jinfeng; Lv, Xiaojian; Mao, Guozhu

    2007-12-01

    Lake areas in urban fringes are under increasing urbanization pressure. Consequently, the conflict between rapid urban development and the maintenance of water bodies in such areas urgently needs to be addressed. An inexact chance-constrained linear programming (ICCLP) model for optimal land-use management of lake areas in urban fringes was developed. The ICCLP model was based on land-use suitability assessment and land evaluation. The maximum net economic benefit (NEB) was selected as the objective of land-use allocation. The total environmental capacity (TEC) of water systems and the public financial investment (PFI) at different probability levels were considered key constraints. Other constraints included in the model were land-use suitability, governmental requirements on the ratios of various land-use types, and technical constraints. A case study implementing the system was performed for the lake area of Hanyang at the urban fringe of Wuhan, central China, based on our previous study on land-use suitability assessment. The Hanyang lake area is under significant urbanization pressure. A 15-year optimal model for land-use allocation is proposed during 2006 to 2020 to better protect the water system and to gain the maximum benefits of development. Sixteen constraints were set for the optimal model. The model results indicated that NEB was between 1.48 × 109 and 8.76 × 109 or between 3.98 × 109 and 16.7 × 109, depending on the different urban-expansion patterns and land demands. The changes in total developed area and the land-use structure were analyzed under different probabilities ( q i ) of TEC. Changes in q i resulted in different urban expansion patterns and demands on land, which were the direct result of the constraints imposed by TEC and PFI. The ICCLP model might help local authorities better understand and address complex land-use systems and develop optimal land-use management strategies that better balance urban expansion and grassland

  19. Ecological Succession, Land use Changes and Soil Organic C Stock in a Lake Retreat Area (Main Ethiopian Rift Valley)

    NASA Astrophysics Data System (ADS)

    Nyssen, J.; Temesgen, H.; Lemenih, M.; Zenebe, A.; Kindu, M.; Haile, M.

    2007-12-01

    In the Main Ethiopian Rift Valley, ecological succession is related to continuous lake retreat (Nyssen et al., 2004). Human activities, through their impact on land use and cover, affect this ecological succession. Through a remote sensing study, we extricated ecological succession and human activity as causative factors for land use and cover changes (LUCC) and explored which impact this has on soil organic C (SOC) stock in lake retreat areas. Remote sensing data used include a Landsat MSS from 1973, a Landsat TM from 1986 and a Landsat ETM+ from 2000. A conventional type of classification was used whereby supervised classification of the 2000 image was supplemented by unsupervised classification of the older datasets. Due to decreased rainfall and water abstraction for intense irrigated agriculture and floriculture in its catchment, Lake Abijata lost 46 % of its area between 2000 and 2006. On the emerged lands, a good ecological succession was observed between 1973 and 1986, with clear evidence for: emerged land -> grassland -> Acacia bushes -> open woodland. Between 1986 and 2000, LUCC tendencies were totally reversed and woody vegetation decreased strongly, indicating increased human impact (Habtamu et al., 2007). Based on an analysis of the Landsat imagery, coupled with soil and land use studies, determinants for SOC stock were found. Firstly, SOC stock significantly differs between cultivated land and grazing land (3301 and 2626 g m-2) on the one hand, and woodland (4594 g m-2) on the other. The strongest explanation of SOC stock is related to the duration of emergence and hence of pedogenesis. Its proxy, elevation, explains much of the variability of SOC (R2 = 0.48). Using a multiple regression model involving elevation and IR reflectance, the SOC stock in the study area could be assessed at 2196 (+ - 1517) g m-2 SOC in 2000, against 3222 (+ - 1639) g m-2 in 1973 (Nyssen et al., 2007), which is related to the post-1986 reversing of ecological succession in

  20. Lakeview uranium area, Lake County, Oregon - constraints on genetic modelling from a district-scale perspective

    SciTech Connect

    Weissenburger, K.W.

    1984-01-01

    Extent-of-outcrop geologic mapping (1:12,000) on the Cox Flat 7.5-minute quadrangle establishes the stratigraphy and structure near the White King uranium mine, about 25 km northwest of Lakeview, Lake County, Oregon. Bedrock includes an Oligocene andesitic volcanic/sedimentary section, four late Oligocene rhyodacitic ignimbrite sequences, a late Oligocene/Miocene tuffaceous section, locally thick early to late Miocene basaltic flows, and an interbedded sequence of late Miocene (about 7-8 Ma old) felsic tuffs and thin basalt flows. Relatively intense down-to-the northeast normal faulting and southwestward stratal tilting resulted from a pre-Basin-and-Range extensional tectonic regime with an ENE least-principal stress orientation. This faulting and tilting began after the late Oligocene ignimbrite volcanism and before the spread of Coleman Rim-equivalent basalt flows. The interpreted geology constrains genetic models, resource estimates, and exploration strategies for uranium occurrences in the Lakeview area. Fault- and fracture-controlled hydrothermal uranium deposits are restricted to favorable stratigraphic horizons of the Miocene section with the important exception of porous and permeable upper portions of the late Oligocene section. Previous models have stressed the importance of intrusive rhyolite plug domes as sources of uranium and/or heat in ore genesis and targeted exploration efforts at dome contacts. Mass balance and other arguments show that an association with rhyolite domes is not a necessary criterion for ore formation or exploration.

  1. Nitrogen export from an agriculture watershed in the Taihu Lake area, China.

    PubMed

    Gao, C; Zhu, J G; Zhu, J Y; Gao, X; Dou, Y J; Hosen, Y

    2004-01-01

    Temporal changes in nitrogen concentrations and stream discharge, as well as sediment and nitrogen losses from erosion plots with different land uses, were studied in an agricultural watershed in the Taihu Lake area in eastern China. The highest overland runoff loads and nitrogen losses were measured under the upland at a convergent footslope. Much higher runoff, sediment and nitrogen losses were observed under upland cropping and vegetable fields than that under chestnut orchard and bamboo forest. Sediment associated nitrogen losses accounted for 8-43.5% of total nitrogen export via overland runoff. N lost in dissolved inorganic nitrogen forms (NO(3-)-N + NH4+-N) accounted for less than 50% of total water associated nitrogen export. Agricultural practices and weather-driven fluctuation in discharge were main reasons for the temporal variations in nutrient losses via stream discharge. Significant correlation between the total nitrogen concentration and stream discharge load was observed. Simple regression models could give satisfactory results for prediction of the total nitrogen concentrations in stream water and can be used for better quantifying nitrogen losses from arable land. Nitrogen losses from the studied watershed via stream discharge during rice season in the year 2002 were estimated to be 10.5 kg N/ha using these simple models. PMID:15499775

  2. [Temporal and spatial distribution characteristics of nitrogen losses in hilly area of Taihu Lake].

    PubMed

    Wang, Peng; Gao, Chao; Yao, Qi; Han, Long-Xi; Shen, Xia

    2006-08-01

    Four typical land uses in hilly area of Taihu Lake were studied on temporal and spatial distribution characteristics of nitrogen losses in surface runoff under natural rainfall through experiment in situ. The medium value of event mean concentration (EMC) of ammonia nitrogen (NH4(+) -N) which dominated agricultural N in surface runoff accounted for 44.5% of total nitrogen (TN), while nitrite nitrogen (NO2(-) -N) accounted for 1.8%. Concentration of nitrogen in runoff had significantly seasonal variation which was related to meteorologic conditions such as rainfall, temperature, and agricultural activities. Temporal variabilities of site mean concentration (SMC) for TN, NH4(+) -N, NO3(-) -N and NO2(-) -N were decreased sequentially. The highest SMC value of TN, NH(+) -N and NO3(-) -N in upland runoff and N2(-) -N in bamboo grove were observed. The spatial distribution of nitrogen losses was determined by fertilizer application and vegetation coverage. Spatial variabilities for SMC of nitrogen were less than temporal variabilities. It was found that transportation fluxes of nitrogen in surface runoff from upland and vegetable plot were higher than that from chestnut orchard and bamboo forest which have significantly related to surface runoff volume. PMID:17111632

  3. DOE feasibility report on Lake Calumet area refuse-to-energy facility

    SciTech Connect

    1980-06-18

    Site analyses and literature reviews were conducted to determine the feasibility of building an energy-producing municipal waste incinerator at Calumet Lake, Illinois. The amount of burnable waste produced within 5 and 10 miles of the near-Chicago site, the composition and heating value of this solid waste, and the air pollution impacts of waste incineration were determined, and the economic value of recovered material or of steam and electricity produced at the plant are discussed. It is concluded that there is sufficient refuse in the area to support a refuse processing center, that increasng landfill costs make such a center economically attractive, and that the Btu content of the refuse is adequate to produce steam for heat and power use. Replacing existing oil-fired power plants with this facility would result in an 88% reduction in current pollutant emission levels. There is a ready market for steam that could be produced. It is recommended that steps be taken to implement the establishment of the proposed waste processing center. (LCL)

  4. Hydrogeochemical investigations in a drained lake area: the case of Xynias basin (Central Greece).

    PubMed

    Charizopoulos, Nikos; Zagana, Eleni; Stamatis, Georgios

    2016-08-01

    In Xynias drained Lake Basin's area, central Greece, a hydrogeochemical research took place including groundwater sampling from 30 sampling sites, chemical analysis, and statistical analysis. Groundwaters present Ca-Mg-HCO3 as the dominant hydrochemical type, while their majority is mixed waters with non-dominant ion. They are classified as moderately hard to hard and are characterized by oxidizing conditions. They are undersaturated with respect to gypsum, anhydrite, fluorite, siderite, and magnesite and oversaturated in respect to calcite, aragonite, and dolomite. Nitrate concentration ranges from 4.4 to 107.4 mg/L, meanwhile 13.3 % of the samples exceed the European Community (E.C.) drinking water permissible limit. The trace elements Fe, Ni, Cr, and Cd present values of 30, 80, 57, and 50 %, respectively, above the maximum permissible limit set by E.C. Accordingly, the majority of the groundwaters are considered unsuitable for drinking water needs. Sodium adsorption ratio values (0.04-3.98) and the electrical conductivity (227-1200 μS/cm) classify groundwaters as suitable for irrigation uses, presenting low risk and medium soil alkalization risk. Factor analysis shows that geogenic processes associated with the former lacustrine environment and anthropogenic influences with the use of fertilizers are the major factors that characterized the chemical composition of the groundwaters. PMID:27450374

  5. [The epidemiologic surveillance of malignant mesothelioma in the Lower Iseo Lake area].

    PubMed

    Barbieri, Pietro Gino; Somigliana, Anna; Caironi, Massimo; Migliori, Maurizio

    2007-01-01

    Starting from an hospital observation of the mesotheliomas cluster in women living in a lakeside area (Iseo lake, Northern Italy), an epidemiological surveillance of this tumour was performed by the local occupational health service. This cluster wasn't notified, in spite of the relevant number of factories producing asbestos textile materials in this area. From 1977 to august 2006, 45 cases of mesothelioma were detected among the workers of 3 textile industries located in 3 little villages: 14 cases occurred working crocidolite and chrysotile rope and gasket; 20 cases in a textile factory producing cotton garments, that was adjacent to and polluted by the farmer and were asbestos insulation and blankets used for fireproofing are present; 11 cases occurred among women working in silk factories. The mesothelioma cases occurred in the same period in this area, which constituted the recruitment area of the people working in the 3 textile plants (11 villages, about 43,000 inhabitants), are 55.93% of which had been occupationally exposed to asbestos. Out of the dockyard and the asbestos-cement industries, this frequency of occupational exposed workers is the highest never observed in Italy. The majority of the cases (66%) occurred among women working in the textile factories. In a women, producing asbestos textile materials and suffered form peritoneal mesothelioma and pleural plaques, the analysis (by SEM) of asbestos fibre lung burden show 286 million fibres x gr. of dry tissue. Between the 42 mesothelioma cases occurring in the population of the 3 villages where the textile plants was located, we observed only one case with possible environmental exposure to asbestos: a gardener of the village where the manufacturing asbestos ropes and gasket plant is present. In the silk factories, asbestos exposure was probable because of the presence of asbestos insulated pipes. The female pleural mesothelioma standard incidence observed in this area (6.8 x 100,000, 1977-2005) is

  6. Detailed study of selenium in soil, water, bottom sediment, and biota in the Sun River Irrigation Project, Freezout Lake Wildlife Management Area, and Benton Lake National Wildlife Refuge, west-central Montana, 1990-92

    USGS Publications Warehouse

    Nimick, D.A.; Lambing, J.H.; Palawski, D.U.; Malloy, J.C.

    1996-01-01

    Selenium and other constituents are adversely affecting water quality and creating a potential hazard to wildlife in several areas of the Sun River Irrigation Project, Freezout Lake Wildlife Management Area, and Benton Lake National Wildlife Refuge in west-central Montana. Selenium derived from Cretaceous shale and Tertiary and Quaternary deposits containing shale detritus is transported in the oxic shallow ground-water systems. At Freezout Lake Wildlife Management Area, drainage from irrigated glacial deposits is the primary source of selenium; drainage from non-irrigated farmland is a significant source locally. Benton Lake generally receives more selenium from natural runoff from its non-irrigated basin than from the trans-basin diversion of irrigation return flow. Selenium has accumulated in aquatic plants and invertebrates, fish, and water birds, particularly in wetlands that receive the largest selenium loads. Although selenium residues in biological tissue from some wetland units exceeded biological risk levels, water-bird reproduction generally has not been impaired. The highest selenium residues in biota commonly occurred in samples from Priest Butte Lakes, which also had the highest selenium concentration in wetland water. Selenium concentrations in all invertebrate samples from Priest Butte Lakes and the south end of Freezeout Lake exceeded the critical dietary threshold for water birds. Selenium delivered to wetlands accumulates in bottom sediment, predominantly in near-shore areas. Potential impacts to water quality, and presumably biota, may be greatest near the mouths of inflows. Most selenium delivered to wetlands will continue to accumulate in bottom sediment and biota.

  7. Glacioisostasy and Lake-Level Change at Moosehead Lake, Maine

    USGS Publications Warehouse

    Balco, G.; Belknap, D.F.; Kelley, J.T.

    1998-01-01

    Reconstructions of glacioisostatic rebound based on relative sea level in Maine and adjacent Canada do not agree well with existing geophysical models. In order to understand these discrepancies better, we investigated the lake-level history of 40-km-long Moosehead Lake in northwestern Maine. Glacioisostasy has affected the level of Moosehead Lake since deglaciation ca. 12,500 14C yr B.P. Lowstand features at the southeastern end and an abandoned outlet at the northwestern end of the lake indicate that the lake basin was tilted down to the northwest, toward the retreating ice sheet, by 0.7 m/km at 10,000 14C yr B.P. Water level then rose rapidly in the southeastern end of the lake, and the northwestern outlet was abandoned, indicating rapid relaxation of landscape tilt. Lowstand features at the northwestern end of the lake suggest that the lake basin was tilted to the southeast at ca. 8750 14C yr B.P., possibly as the result of a migrating isostatic forebulge. After 8000 14C yr B.P., water level at the southeastern end was again below present lake level and rose gradually thereafter. We found no evidence suggesting that postglacial climate change significantly affected lake level. The rebound history inferred from lake-level data is consistent with previous interpretations of nearby relative sealevel data, which indicate a significantly steeper and faster-moving ice-proximal depression and ice-distal forebulge than geophysical models predict. ?? 1998 University of Washington.

  8. Impacts of land use change on hydrological components and macroinvertebrate distributions in the Poyang lake area

    NASA Astrophysics Data System (ADS)

    Schmalz, Britta; Kuemmerlen, Mathias; Kiesel, Jens; Jähnig, Sonja C.; Fohrer, Nicola

    2014-05-01

    Climate and land use changes affect river ecosystems globally and cause environmental impacts at different spatial and temporal scales. An integrated modelling approach for depicting the effect of environmental changes on aquatic ecosystems was developed and tested. Catchment characteristics, the flow regime and the distribution of aquatic organisms were linked together. The Changjiang river catchment (1717 km²), as part of the Poyang Lake basin in China, was selected as the test area. Measuring and sampling campaigns at 50 locations were carried out for collecting land use, hydrological, hydraulic and biological (macroinvertebrate) data. The water balance of the catchment was modeled with the ecohydrological model SWAT (Soil and Water Assessment Tool). The streamflow time series computed with SWAT at each of the 50 sampling points were tranfered to the species distribution model BIOMOD which predicted the occurrence of macroinvertebrates in the stream network based on hydrological, climatic and topographic variables. The SWAT modeling results showed high temporal dynamics where 72% of the annual streamflow occurred during the monsoon season from March to July. Due to various slopes, soil characteristics, land cover and associated land management, a high spatial variability of surface runoff between the subbasins and HRUs was detected. The highest values occurred on agricultural land with cabbage cultivation, the lowest in forest areas. The SWAT model indicates that deforestation scenarios result in higher streamflow, higher surface runoff and altered flow patterns compared with the base model. In contrast, model runs representing afforestation showed opposite trends. The predictions for the stream macroinvertebrate community, arising from the integrated modelling framework were found to be suitable for describing changing environmental conditions. The deforestation scenario reduced macroinvertebrate richness through the increase in agriculture and tea plantations.

  9. Comparison of electrofishing and rotenone for sampling largemouth bass in vegetated areas of two Florida lakes

    USGS Publications Warehouse

    Tate, W.B.; Allen, M.S.; Myers, R.A.; Estes, J.R.

    2003-01-01

    We compared the sampling precision and efficiency of electrofishing and rotenone for assessing populations of largemouth bass Micropterus salmoides in vegetated portions of two Florida lakes. Sampling was conducted at Lochloosa and Orange lakes in north-central Florida from 1990 to 1999. Significant differences in length frequencies were determined between the two methods in 5 of 9 years for each lake. In years where differences existed, electrofishing collected larger fish than did rotenone. The maximum deviation between cumulative relative length frequencies for the two methods was not related to total vegetation, native emergent vegetation, or hydrilla Hydrilla verticallata coverage at either lake. Sampling precision was greater for electrofishing than for rotenone; electrofishing also required less sampling effort to detect changes in the abundance of juvenile and adult largemouth bass. Electrofishing was a more precise and cost-effective method than rotenone for estimating largemouth bass abundance.

  10. Hydrologic data and description of a hydrologic monitoring plan for the Borax Lake area, Oregon

    USGS Publications Warehouse

    Schneider, Tiffany Rae; McFarland, William D.

    1995-01-01

    Information from field visits was used to develop a monitoring plan. The plan would include monitoring Borax Lake by measuring discharge, stage, evaporation, temperature, and specific conductance; water-quality sampling and analysis; and monitoring shallow ground-water levels near Borax Lake using shallow piezometers. Minimally, one hot spring in North Borax Lake Spring Group 1 would be monitored for temperature and specific conductance and sampled for water-quality analysis. In addition, two flowing wells would be monitored for water levels, temperature, specific conductance, and discharge and sampled for water-quality analysis. The construction characteristics of these wells must be verified before long-term data collection begins. In the future, it may be helpful to monitor shallow and (or) deep observation wells drilled into the thermal aquifer to understand the possible effects of geothermal development on Borax Lake and nearby springs.

  11. Seroepidemiology of Selected Arboviruses in Febrile Patients Visiting Selected Health Facilities in the Lake/River Basin Areas of Lake Baringo, Lake Naivasha, and Tana River, Kenya

    PubMed Central

    Lwande, Olivia; Orindi, Benedict; Irura, Zephania; Ongus, Juliette; Sang, Rosemary

    2015-01-01

    Abstract Introduction: Arboviruses cause emerging and re-emerging infections affecting humans and animals. They are spread primarily by blood-sucking insects such as mosquitoes, ticks, midges, and sandflies. Changes in climate, ecology, demographic, land-use patterns, and increasing global travel have been linked to an upsurge in arboviral disease. Outbreaks occur periodically followed by persistent low-level circulation. Aim: This study was undertaken to determine the seroepidemiology of selected arboviruses among febrile patients in selected lake/river basins of Kenya. Methods: Using a hospital-based cross-sectional descriptive survey, febrile patients were recruited and their serum samples tested for exposure to immunoglobulin M (IgM) and IgG antibodies against Crimean–Congo hemorrhagic fever virus (CCHFV), Rift Valley fever virus (RVFV), West Nile virus (WNV), and chikungunya virus (CHIKV). Samples positive for CHIKV and WNV were further confirmed by the plaque reduction neutralization test (PRNT). Results: Of the 379 samples examined, 176 were IgG positive for at least one of these arboviruses (46.4%, 95% confidence interval [CI] 41.4–51.5%). Virus-specific prevalence for CCHF, RVF, WN, and CHIK was 25.6%, 19.5%, 12.4%, and 2.6%, respectively. These prevalences varied significantly with geographical site (p<0.001), with Tana recording the highest overall arboviral seropositivity. PRNT results for Alphaviruses confirmed that the actual viruses circulating in Baringo were Semliki Forest virus (SFV) and CHIKV, o'nyong nyong virus (ONNV) in Naivasha, and SFV and Sindbis virus (SINDV) in Tana delta. Among the flaviviruses tested, WNV was circulating in all the three sites. Conclusion: There is a high burden of febrile illness in humans due to CCHFV, RVFV, WNV, and CHIKV infection in the river/lake basin regions of Kenya. PMID:25700043

  12. Spatial patterns in PCB concentrations of Lake Michigan lake trout

    USGS Publications Warehouse

    Madenjian, Charles P.; DeSorcie, Timothy J.; Stedman, Ralph M.; Brown, Edward H., Jr.; Eck, Gary W.; Schmidt, Larry J.; Hesselberg, Robert J.; Chernyak, Sergei M.; Passino-Reader, Dora R.

    1999-01-01

    Most of the PCB body burden in lake trout (Salvelinus namaycush) of the Great Lakes is from their food. PCB concentrations were determined in lake trout from three different locations in Lake Michigan during 1994–1995, and lake trout diets were analyzed at all three locations. The PCB concentrations were also determined in alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), bloater (Coregonus hoyi), slimy sculpin (Cottus cognatus), and deepwater sculpin (Myoxocephalus thompsoni), five species of prey fish eaten by lake trout in Lake Michigan, at three nearshore sites in the lake. Despite the lack of significant differences in the PCB concentrations of alewife, rainbow smelt, bloater, slimy sculpin, and deepwater sculpin from the southeastern nearshore site near Saugatuck (Michigan) compared with the corresponding PCB concentrations from the northwestern nearshore site near Sturgeon Bay (Wisconsin), PCB concentrations in lake trout at Saugatuck were significantly higher than those at Sturgeon Bay. The difference in the lake trout PCB concentrations between Saugatuck and Sturgeon Bay could be explained by diet differences. The diet of lake trout at Saugatuck was more concentrated in PCBs than the diet of Sturgeon Bay lake trout, and therefore lake trout at Saugatuck were more contaminated in PCBs than Sturgeon Bay lake trout. These findings were useful in interpreting the long-term monitoring series for contaminants in lake trout at both Saugatuck and the Wisconsin side of the lake.

  13. Determination of the mineral stability field of evolving groundwater in the Lake Bosumtwi impact crater and surrounding areas

    NASA Astrophysics Data System (ADS)

    Loh, Yvonne Sena Akosua; Yidana, Sandow Mark; Banoeng-Yakubo, Bruce; Sakyi, Patrick Asamoah; Addai, Millicent Obeng; Asiedu, Daniel Kwadwo

    2016-09-01

    Conventional graphical techniques, mass balance geochemical modelling, and multivariate statistical methods were jointly applied to hydrogeochemical data of groundwater from the fractured rock aquifer system, and surface water in the Bosumtwi and surrounding areas to reveal evolutionary trends and the characteristics of evolving groundwater in the area. Four clusters distinguished from the Q-mode hierarchical cluster analysis (HCA) comprised three main groundwater associations and one surface water group (lake water). Although both water resources are of low mineralization (TDS < 1000 mg/l), it was observed that the groundwater from the upper catchment with hydrochemical facies dominated by Nasbnd Mgsbnd HCO3-, evolves to Casbnd Mgsbnd and mixed cations HCO3- water types at the lower reaches. The lake water on the other hand is Nasbnd HCO3- water type. Results from principal component analyses (PCA) and other geochemical interpretations distinguished three sources of variations in the hydrochemistry. Saturation indices of possible reactive mineral phases show groundwater undersaturation relative to albite, anorthite, aragonite, barite, calcite, chlorite, chrysotile, dolomite, gypsum, k-felspar and talc, and supersaturation with respect to gibbsite, kaolinite, Ca-montmorillonite and k-mica in the area. The PCA and other geochemical interpretation identify weathering of feldspars and carbonate mineral dissolution as predominantly influencing the hydrochemistry of the groundwater. Hydrolysis of the aluminosilicates causes the groundwater to reach equilibrium with kaolinite. In addition to dissolution of silicates, the chemical composition of the lake water has been influenced by evaporation and consequent carbonate saturation.

  14. Estimating ground-water exchange with lakes using water-budget and chemical mass-balance approaches for ten lakes in ridge areas of Polk and Highlands counties, Florida

    USGS Publications Warehouse

    Sacks, L.A.; Swancar, Amy; Lee, T.M.

    1998-01-01

    Water budget and chemical mass-balance approaches were used to estimate ground-water exchange with 10 lakes in ridge areas of Polk and Highlands Counties, Florida. At each lake, heads were monitored in the surficial aquifer system and deeper Upper Floridan aquifer, lake stage and rainfall were measured continuously, and lakes and wells were sampled three times between October 1995 and December 1996. The water-budget approach computes net ground-water flow (ground-water inflow minus outflow) as the residual of the monthly waterbudget equation. Net ground-water flow varied seasonally at each of the 10 lakes, and was notably different between lakes, illustrating short-term differences in ground-water fluxes. Monthly patterns in net ground-water flow were related to monthly patterns of other hydrologic variables such as rainfall, ground-water flow patterns, and head differences between the lake and the Upper Floridan aquifer. The chemical mass-balance approach combines the water budget and solute or isotope mass-balance equations, and assumes steady-state conditions. Naturally occurring tracers that were analyzed for include calcium, magnesium, sodium, potassium, chloride, and bromide, the isotopes deuterium and oxygen-18. Chloride and sodium were the most successful solute tracers; however, their concentrations in ground water typically varied spatially, and in places were similar to that in lake water, limiting their sensitivity as tracers. In contrast, the isotopes were more robust tracers because the isotopic composition of ground water was relatively uniform and was distinctly different from the lake water. Groundwater inflow computed using the chemical massbalance method varied significantly between lakes, and ranged from less than 10 to more than 150 inches per year. Both water-budget and chemical mass-balance approaches had limitations, but the multiple lines of evidence gained using both approaches improved the understanding of the role of ground water in the

  15. Risk factors for infectious diseases in backyard poultry farms in the Poyang Lake area, China.

    PubMed

    Wang, Yong; Jiang, Zhiben; Jin, Zhenyu; Tan, Hua; Xu, Bing

    2013-01-01

    Emergence and transmission of infectious diseases have an enormous impact on the poultry industry and present a serious threat to the health of humans and wild birds. Noncommercial poultry operations, such as backyard poultry facilities in China, are potential sources of virus exchange between commercial poultry and wild birds. It is particularly critical in wetland areas where backyard poultry have close contact with commercial poultry and migratory birds, therefore increasing the risk of contracting infectious diseases. To evaluate the transmission risks, a cross-sectional study was undertaken in the Poyang Lake area, China, involving 309 residents in the backyard poultry farms in three counties (Region A, B, and C) of Jiangxi Province. We examined the backyard poultry population, poultry species, presence of poultry deaths from infectious diseases, food sources, and biosecurity practices. Region B ranked highest for biosecurity while region C ranked lowest. The risks of infectious diseases were assessed by adjusted odds ratio based on multivariate logistic regression analysis. Potential risk factors in the three regions of the study site were compared. In Region A, significant factor was contact of poultry with wild birds (OR: 6.573, 95% CI: 2.148-20.115, P=0.001). In Region B, the most significant factor was contact of poultry with neighboring backyard waterfowls (OR: 3.967, 95% CI: 1.555-10.122, P=0.004). In Region C, significant factors were poultry purchase from local live bird markets (OR: 3.740, 95% CI: 1.243-11.255, P=0.019), and contact of poultry with wild birds (OR: 3.379, 95% CI: 1.058-10.791, P=0.040). In summary, backyard poultry was significantly affected by neighboring commercial poultry and close contact with wild birds. The results are expected to improve our understanding of the transmission risks of infectious diseases in a typical backyard poultry environment in rural China, and address the need to improve local farming practices and take

  16. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 425: Area 9 Main Lake Construction Debris Disposal Area, Tonopah Test Range, Nevada

    SciTech Connect

    K. B. Campbell

    2002-04-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the action necessary for the closure of Corrective Action Unit (CAU) 425, Area 9 Main Lake Construction Debris Disposal Area. This CAU is currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO, 1996). This site will be cleaned up under the SAFER process since the volume of waste exceeds the 23 cubic meters (m{sup 3}) (30 cubic yards [yd{sup 3}]) limit established for housekeeping sites. CAU 425 is located on the Tonopah Test Range (TTR) and consists of one Corrective Action Site (CAS) 09-08-001-TA09, Construction Debris Disposal Area (Figure 1). CAS 09-08-001-TA09 is an area that was used to collect debris from various projects in and around Area 9. The site is located approximately 81 meters (m) (265 feet [ft]) north of Edwards Freeway northeast of Main Lake on the TTR. The site is composed of concrete slabs with metal infrastructure, metal rebar, wooden telephone poles, and concrete rubble from the Hard Target and early Tornado Rocket sled tests. Other items such as wood scraps, plastic pipes, soil, and miscellaneous nonhazardous items have also been identified in the debris pile. It is estimated that this site contains approximately 2280 m{sup 3} (3000 yd{sup 3}) of construction-related debris.

  17. Wide area coverage radar imaging satellite for earth applications. [surveillance and mapping of ice on Great Lakes

    NASA Technical Reports Server (NTRS)

    Stevens, G. H.; Ramler, J. R.

    1974-01-01

    A preliminary study was made of a radar imaging satellite for earth applications. A side-looking synthetic-aperture radar was considered and the feasibility of obtaining a wide area coverage to reduce the time required to image a given area was investigated. Two basic approaches were examined; low altitude sun-synchronous orbits using a multibeam/multifrequency radar system and equatorial orbits up to near-synchronous altitude using a single beam system. Surveillance and mapping of ice on the Great Lakes was used as a typical application to focus the study effort.

  18. Bathymetry and selected perspective views of 6 reef and coastal areas in Northern Lake Michigan

    USGS Publications Warehouse

    Barnes, Peter; Fleisher, Guy; Gardner, James V.; Lee, Kristen

    2003-01-01

    We apply state of the art laser technology and derivative imagery to map the detailed morphology and of principal lake trout spawning sites on reefs in Northern Lake Michigan and to provide a geologic interpretation. We sought to identify the presence of ideal spawning substrate: shallow, "clean" gravel/cobble substrate, adjacent to deeper water. This study is a pilot collaborative effort with the US Army Corps of Engineers SHOALS (Scanning Hydrographic Operational Airborne Lidar Survey) program. The high-definition maps are integrated with known and developing data on fisheries, as well as limited substrate sedimentologic information and underlying Paleozoic carbonate rocks.

  19. [Landscape ecological risk assessment and its spatio-temporal variations in Ebinur Lake region of inland arid area].

    PubMed

    Zhang, Yue; Zhang, Fei; Zhou, Mei; Li, Xiao-hang; Ren, Yan; Wang, Juan

    2016-01-01

    The typical region of the Ebinur Lake Basin was chosen as study area. Landsat TM/OLI images for 1998, 2011 and 2013 were obtained. In the study area, landscape was classified into six types, including cropland, woodland, grassland, water body, bare lake bed, salinized land and unutilized land. Landscape indices and ecological risk index were calculated and spatially interpolated for the whole region, which was divided into five different risk zones: extremely low, low, moderate, high and extremely high ecological risk. They were carried out for assessing the spatio-temporal changes in ecological risk for each landscape pattern. The results showed that the regional landscape patterns had experienced significant changes, and the increase in the area of croplands was the main trend in landscape evolution from 1998-2013. The main part of the regional ecosystem faced extremely high risk in 1998, high risk in 2011 and low risk in 2013. The ecological risk level of the study area was significantly decreased in the overall period, and the total area of change from high to low risk was much greater than those from low to high risk. PMID:27228614

  20. Graphically characterizing the movement of a rabid striped skunk epizootic across the landscape in northwestern Wyoming.

    PubMed

    Ramey, Craig A; Mills, Kenneth W; Fischer, Justin W; McLean, Robert G; Fagerstone, Kathleen A; Engeman, Richard M

    2013-09-01

    A striped skunk (Mephitis mephitis) rabies epizootic in northwestern Wyoming was studied from the Index Case in 1988 to the last case in 1993, and possibly is the first rabies epizootic in a previously rabies-free zone monitored from beginning to end. The 843 km(2) study area comprised skunk habitat along 90 km of Shoshone River's floodplain from Bighorn Lake upstream to Cody. Of 1,015 skunks tested, 215 were rabies-positive. Integrating spatial and temporal data from positive cases, we analyzed the epizootic's movements and dynamics at 6-month intervals using multivariate movement maps, a new multivariate descriptive methodology presented here to demonstrate the epizootic's directional flow, while illustrating areas with higher case densities (i.e., wave crests). This approach should help epidemiologists and public health officials to better understand future rabies epizootics. PMID:23812724

  1. The disappearing of the largest lake in the Middle East: Geochemical clues for human impact on Urmia salt lake NW Iran

    NASA Astrophysics Data System (ADS)

    Sharifi, O.; Haeri-Ardakani, O.; Pourmand, A.

    2012-12-01

    The water level in Lake Urmia, the third largest saline lake on earth and the largest continental lake in the Middle East, has dropped by more than 9 m over the last two decades, with no signs of improvement in recent years. Urmia is a hypersaline shallow lake (average salinity ~200 ‰) located in a closed continental drainage basin in northwestern Iran, and is surrounded by a variety of rock formations, ranging in age from Precambrian metamorphic complexes to Holocene mud deposits. Lake sediments are composed of two major components; chemical-biochemical and clastic fractions. Based on grain size analysis of samples from 24 push-cores, silt-size particles dominate the lake's sediments with clay-bearing materials mostly present near the center of the lake. Sand-size particles are dominant in the northwest, where felsic to intermediate plutonic and metamorphic rocks are located in the proximity of the lake. The water of the Urmia Lake can be classified as Na-K-Cl-Mg-SO4 brine. Based on chemical analysis of conservative lithogenic elements (e.g., Ti, Si, Al, Ca) as well as redox-sensitive elements (e.g., Fe, K, Rb, Sr) in the clastic fraction of the lake's sediment, elemental distributions are reflective of regional geology. The main sources of ions to the lake are evaporite formations with minor contribution from igneous rocks. Ion concentrations in the northern part of the lake are nearly constant throughout the year while south-southeastern parts of the lake show variable annual ion concentration due to major fresh water inflows. Chemical analysis of the surface sediment samples for heavy metals (Ni, Cr, V and Hg) indicate moderate to high degrees of contamination in the affected areas, where Hg is the most abundant heavy metal. The highest concentrations of Hg (Normalized Enrichment Factor =6) are observed in the middle part of the lake, where intensive dredging and construction activities have taken place. In contrast, the lowest concentrations of Hg in

  2. Evapotranspiration from successional vegetation in a deforested area of the Lake Wales Ridge, Florida

    USGS Publications Warehouse

    Sumner, D.M.

    1996-01-01

    The suitability of three evapotranspiration models (Penman-Monteith, Penman, and a modified Priestley-Taylor) was evaluated at a site ofsuccessional vegetation in a deforested area of theLake Wales Ridge, Florida. Eddy correlation mea surements of evapotranspiration made during 22approximately 1-day periods at a temporal resolu tion of 20 minutes from September 1993 to August 1994 were used to calibrate the evapotranspiration models. Three variants of the eddy correlation method that ascribe measurement error to three different sources were considered in the analysis. The Penman-Monteith and modified Priestley- Taylor models were successful in approximating measured 20-minute values of evapotranspiration (r2  0.918). The most suc cessful approaches were the modified Priestley-Taylor model (r2 = 0.972) and a nontraditional and simplified form of the Penman-Monteith model (r2 = 0.967). The Penman approach was unsuccessful as a predictor of evapotranspiration. The evapotranspiration models were used to estimate evapotranspiration between measure ments. When evapotranspiration values measured with a Bowen ratio variant of the eddy correlation method were used for model calibration, estimated daily evapotranspiration rates varied sea sonally ranging from 0.2 millimeters per day (0.008 inch per day) in late December 1993 to5 millimeter per day (0.2 inch per day) in mid-July 1994. Annual evapotranspiration (September 15, 1993, to September 15, 1994) was estimated to be about 680 millimeters (27 inches).Evapotranspiration models calibrated to the stan dard eddy correlation method and to an energy- balance residual variant provided estimates ofannual evapotranspiration that were about 10 per cent lower and higher, respectively. These dataindicate that of the 1,320 millimeters (52 inches)of precipitation during the 1-year period, about 570 to 700 millimeters (22 to 28 inches) recharged the surficial aquifer. Evapotranspiration at this study site probably defines the lower

  3. ICCLP: an inexact chance-constrained linear programming model for land-use management of lake areas in urban fringes.

    PubMed

    Liu, Yong; Qin, Xiaosheng; Guo, Huaicheng; Zhou, Feng; Wang, Jinfeng; Lv, Xiaojian; Mao, Guozhu

    2007-12-01

    Lake areas in urban fringes are under increasing urbanization pressure. Consequently, the conflict between rapid urban development and the maintenance of water bodies in such areas urgently needs to be addressed. An inexact chance-constrained linear programming (ICCLP) model for optimal land-use management of lake areas in urban fringes was developed. The ICCLP model was based on land-use suitability assessment and land evaluation. The maximum net economic benefit (NEB) was selected as the objective of land-use allocation. The total environmental capacity (TEC) of water systems and the public financial investment (PFI) at different probability levels were considered key constraints. Other constraints included in the model were land-use suitability, governmental requirements on the ratios of various land-use types, and technical constraints. A case study implementing the system was performed for the lake area of Hanyang at the urban fringe of Wuhan, central China, based on our previous study on land-use suitability assessment. The Hanyang lake area is under significant urbanization pressure. A 15-year optimal model for land-use allocation is proposed during 2006 to 2020 to better protect the water system and to gain the maximum benefits of development. Sixteen constraints were set for the optimal model. The model results indicated that NEB was between $1.48 x 10(9) and $8.76 x 10(9) or between $3.98 x 10(9) and $16.7 x 10(9), depending on the different urban-expansion patterns and land demands. The changes in total developed area and the land-use structure were analyzed under different probabilities (q ( i )) of TEC. Changes in q ( i ) resulted in different urban expansion patterns and demands on land, which were the direct result of the constraints imposed by TEC and PFI. The ICCLP model might help local authorities better understand and address complex land-use systems and develop optimal land-use management strategies that better balance urban expansion and

  4. Estimation of evaporation from Ned Wilson Lake, Flat Tops Wilderness Area, Colorado

    USGS Publications Warehouse

    Spahr, N.E.; Turk, J.T.

    1985-01-01

    As part of an effort to define the hydrology and water quality of Ned Wilson Lake, evaporation rates were estimated for the summer periods of 1983 and 1984. Mass-transfer and energy-budget techniques and the Morton model were used to estimate evaporation using data collected at the lake and data collected at a meteorological station 0.1 mile from the lake. The estimate of evaporation for July 29 through September 27, 1983, using the mass-transfer technique, was 9.50 inches; the estimate using the energy-budget technique was 8.10 inches; the estimate using the Morton model was 9.90 inches. The evaporation estimate for July 18 through September 25, 1984, using the mass-transfer technique was 8.71 inches; the estimate using the energy-budget technique was 7.88 inches; the estimate using the Moron model was 10.49 inches. These estimates will provide values to be used in future analyses of the interaction of lake and groundwater; however, refinement of data collection will be necessary to determine specifically the rate of evaporation. (USGS)

  5. Distribution of Gull Specific Molecular Marker in Coastal Areas of Lake Ontario

    EPA Science Inventory

    Gulls have been implicated as primary sources of fecal contamination in the Great Lakes, a fact that may have health implications due to the potential spread of microbial pathogens by waterfowl. To better understand the spatial variability of gull fecal contamination, a gull-spe...

  6. Currents and Undercurrents: An Administrative History of Lake Roosevelt National Recreation Area.

    ERIC Educational Resources Information Center

    McKay, Kathryn L.; Renk, Nancy F.

    The 1,259-mile Columbia River flows out of Canada and across eastern Washington state, forming the border between Washington and Oregon. In 1941 the federal government dammed the Columbia River at the north end of Grand Coulee, creating a man-made reservoir named Lake Roosevelt that inundated homes, farms, and businesses, and disrupted the lives…

  7. 75 FR 22228 - Regulated Navigation Area; Lake Champlain Bridge Construction Zone, NY and VT

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-28

    ... FR 3316). Public Meeting We do not now plan to hold a public meeting. You may submit a request for... for public safety by safeguarding both mariners and construction workers during the bridge's... public and construction worker safety for the duration of the planned Lake Champlain Bridge...

  8. Seismicity, seismotectonics and crustal structure of the southern Kenya Rift-new data from the Lake Magadi area

    NASA Astrophysics Data System (ADS)

    Ibs-von Seht, M.; Blumenstein, S.; Wagner, R.; Hollnack, D.; Wohlenberg, J.

    2001-08-01

    Local seismic activity has been monitored in the southern part of the Kenya Rift in the area around Lake Magadi. An earthquake recording network consisting of 15 station sites was operated for 8months from November 1997 to June 1998. During this period, the Magadi area proved to be seismically active. Approximately 10 events per day were detected and found to be equally distributed over the rift floor. The hypocentre depth distribution shows surprisingly large depths of up to 27km in the south and much shallower depths in the northern part of the area. Apart from the background activity, swarm activity with rates of more than 300 events per day was also recorded. The epicentres are clustered and trace a linear structure lying SSW-NNE over a length of 10km north of Lake Magadi. Hypocentres in the region of the earthquake cluster are shallow and exhibit a sharp cut-off at 9km depth. A surface crack that occurred during the recording period is connected to the earthquake swarm. Analysis of the focal mechanisms of selected earthquakes indicates predominantly normal faulting in response to a WNW-ESE-directed tensional stress field. This direction corresponds to the general alignment of the southernmost part of the Kenya Rift and to the surface faulting pattern inside the rift. The crustal structure of the area has been investigated using local earthquake tomography and the spatial distribution of hypocentres. The main results of the tomography are a linear positive velocity anomaly following the rift axis and a negative anomaly at shallow depth underneath Lake Magadi. The high velocities can be explained by mafic material that has intruded into the upper crust. The negative anomaly is attributed to highly fractured rocks. Maximum hypocentre depths indicate a body of low shear strength centred at the rift axis and a general deepening of the brittle-ductile transition from north to south.

  9. General Ecological Characteristics Based on GIS Methods in Poyrazlar Lake, Turkey

    NASA Astrophysics Data System (ADS)

    Ikiel, C.; Kilic, D. E.; Atalay Dutucu, A.

    2012-04-01

    General Ecological Characteristics Based on GIS Methods in Poyrazlar Lake, Turkey Cercis Ikiel Derya Evrim Kilic• Ayse Atalay Dutucu Sakarya University, Art and Science Faculty, Department of Geography, Sakarya, Turkey In this research, general ecological features in Poyrazlar lake is investigated. The study area is located in the east part of Marmara region and north-western part of the Adapazari plain (north-western part of Turkey) between the coordinates of 40°48'-40°52' N and 30°23'-30°30' E. Research area is within phytogeographical region of Euro-Siberian that is among flora and phytogeographical region of Turkey. The main element of vegetation consists Humid-Mild Deciduous forests (especially Quercus spp.) and hydrophyte plants (such as reeds and Nymphaea alba L.). Poyrazlar lake, that's water is fresh, is one of the important wetland areas in the region with its ecological characteristics. Especially the research area is haunted by various migratory birds and it is an important recreation area. The objective of this study is to analyze particularly the formation of Poyrazlar lake, ecological features of this area and negative influence of surrounding human activities in the area. For this purpose topography, geology, soil maps, forest arrangement plan, Spot 5 (2010 period) satellite image for current land use map and field observations data are used. These images are analyzed by utilizing data image processing techniques in ERDAS Imagine© 10.0 and ArcGIS© 10.0 software. Keywords: Ecology; Ecological Features; GIS; Alluvial Dam Lake; Poyrazlar Lake

  10. RV Ocean Surveyor cruise O1-02-GM: bathymetry and acoustic backscatter of selected areas of the outer continental shelf, northwestern Gulf of Mexico; June 8, through June 28, 2002; Iberia, LA to Iberia, LA

    USGS Publications Warehouse

    Beaudoin, Jonathan D.; Gardner, James V.; Clarke, John E. Hughes

    2002-01-01

    Following the publication of high-resolution multibeam echosounder (MBES) images and data of the Flower Gardens area of the northwest Gulf of Mexico outer continental shelf (Gardner et al., 1998), the Flower Gardens Banks National Marine Sanctuary (FGBNMS) and the Minerals Management Service (MMS) have been interested in additional MBES data in the area. A coalition of FGBNMS, MMS, and the US Geological Survey (USGS) was formed to map additional areas of interest in the northwestern Gulf of Mexico in 2002. The areas were chosen by personnel of the FGBNMS and the choice of MBES was made by the USGS. MMS and FGBNMS funded the mapping and the USGS organized the ship and multibeam systems through a Cooperative Agreement between the USGS and the University of New Brunswick. The University of New Brunswick (UNB) contracted the RV Ocean Surveyor and the EM1000 MBES system from C&C Technologies, Inc., Lafayette, LA. C&C personnel oversaw data collection whereas UNB personnel conducted the cruise and processed all the data. USGS personnel were responsible for the overall cruise including the final data processing and digital map products.

  11. The Experimental Lakes Area: Over 45 Years of Whole Ecosystem Monitoring and Manipulation Experiments and a Focus on the Future

    NASA Astrophysics Data System (ADS)

    Emmerton, C. A.

    2015-12-01

    The IISD Experimental Lakes Area is a unique facility which has existed since 1968 and consists of 58 lakes and their watersheds set aside for research purposes. The IISD-ELA also boasts an on-site water chemistry lab, accommodations and facilities for up to 60 personnel. Since its inception in 1968 over 50 whole ecosystem experiments have been conducted at the ELA including eutrophication, acidification of lakes, environmental mercury fates, hydro-electric reservoir impacts and much more. The recent partnership between IISD and ELA has allowed ELA to refocus on freshwater research and policy development in a time where the preservation of the earth's most precious resource is of the utmost concern. In addition to water quality monitoring, the ELA is also focused on autotrophic ecology, zooplankton community structures, fish population and behaviour and food-web interactions. Monitoring all of these disciplines and their inter-relationships gives the research facility a unique perspective and along with the long term dataset stretching back to 1968 the ELA can look at historical records to monitor long term changes in the environment.

  12. Assessing the atmospheric deposition of mercury to Lake Michigan: The importance of the Chicago/Gary urban area on wet and dry deposition

    NASA Astrophysics Data System (ADS)

    Landis, Matthew Scott

    1998-12-01

    Mercury is a toxic bioaccumulative substance found in aquatic ecosystems. The results of the first study of atmospheric mercury deposition into Lake Michigan and the relative importance of the Chicago/Gary urban area were investigated as part of the Lake Michigan Mass Balance Study (LMMBS) and the Atmospheric Exchange Over Lakes and Oceans Study (AEOLOS). Event wet-only precipitation, total aerosol, and vapor phase samples were collected for mercury and trace element determinations from five sites around Lake Michigan from July 1994 through October 1995 as part of the LMMBS. In addition, intensive over-water measurements were conducted aboard the EPA research vessel Lake Guardian during the summer of 1994 and the winter of 1995 as part of the AEOLOS. Atmospheric mercury concentrations were from two to ten times higher in the Chicago/Gary urban area. Wet and dry Hg deposition (including reactive gaseous Hg) were calculated to Lake Michigan using a hybrid receptor modeling framework. The model utilized mercury monitoring data collected during the LMMBS and AEOLOS together with high resolution over-water meteorological data provided by the National Oceanic and Atmospheric Administration. Atmospheric deposition was found to be the primary pathway for mercury input to Lake Michigan, contributing approximately 84% of the estimated 1419 Kg annual flux. Wet deposition (10.6 μg m-2) and dry deposition (10.0 μg m-2) contributed almost equally to the annual atmospheric Hg deposition of 20.6 μg m-2 (1189 Kg). A strong urban influence was observed in the over-water mercury deposition estimates in the southern portion of the lake. An independent meteorological transport analysis determined that local sources in the Chicago/Gary urban area significantly impacted the LMMBS sites around Lake Michigan. The Chicago/Gary urban area was found to contribute about 20% (127 Kg) of the annual atmospheric mercury deposition to Lake Michigan. Multivariate statistical analysis of

  13. Paleomagnetic data bearing on style of Miocene deformation in the Lake Mead area, Southern Nevada

    USGS Publications Warehouse

    Wawrzyniec, T.F.; Geissman, J.W.; Anderson, R.E.; Harlan, S.S.; Faulds, J.

    2001-01-01

    Paleomagnetic and structural data from intermediate to mafic composition lava flows and related dikes in all major blocks of the late Miocene Hamblin-Cleopatra Volcano, which was structurally dismembered during the development of the Lake Mead Fault System (LMFS), provide limits on the magnitude and sense of tilting and vertical axis rotation of crust during extension of this part of the Basin and Range province. Sinistral separation along the fault system dissected the volcano into three major blocks. The eastern, Cleopatra Lobe of the volcano is structurally the most intact section of the volcano. Normal and reverse polarity data from paleomagnetic sites collected along traverses in the Cleopatra Lobe yield an in situ grand mean of Declination (D) = 339??, Inclination (I) = +54??, ??95 = 3.1??, k = 27.2, N = 81 sites. The rocks of the central core of the volcano yield an in situ grand mean of D = 3??, I = + 59??, ??95 = 6.8??, k = 42.5, N = 11 sites (six normal, five reverse polarity). Sites collected within the western Hamblin Lobe of the volcano are exclusively of reverse polarity and yield an overall in situ mean of D = 168??, I = -58??, ??95 = 6.5??. k = 28.9, N = 18 sites. Interpretation of the paleomagnetic data in the context of the structural history of the volcano and surrounding area, considers the possibility of two different types of structural corrections. A stratigraphic tilt correction involves restoring flows to the horizontal using the present strike. This correction assumes no initial, possibly radial, dip of flows of the volcano and is considered invalid. A structural tilt correction to the data assumes that dikes of the radiating swarm associated with the volcano were originally vertical and results in block mean directions of D = 9??, I = +53??, ??95 = 3.1??, k = 27.2, and D = 58??, I = + 78??, ??95 = 6.8, k = 42.5, for the Cleopatra Lobe and the central intrusive core, respectively. The data from the Cleopatra Lobe are slightly discordant

  14. Paleomagnetic data bearing on style of Miocene deformation in the Lake Mead area, southern Nevada

    NASA Astrophysics Data System (ADS)

    Wawrzyniec, Tim F.; Geissman, John W.; Anderson, R. Ernest; Harlan, Steve S.; Faulds, James

    2001-08-01

    Paleomagnetic and structural data from intermediate to mafic composition lava flows and related dikes in all major blocks of the late Miocene Hamblin-Cleopatra Volcano, which was structurally dismembered during the development of the Lake Mead Fault System (LMFS), provide limits on the magnitude and sense of tilting and vertical axis rotation of crust during extension of this part of the Basin and Range province. Sinistral separation along the fault system dissected the volcano into three major blocks. The eastern, Cleopatra Lobe of the volcano is structurally the most intact section of the volcano. Normal and reverse polarity data from paleomagnetic sites collected along traverses in the Cleopatra Lobe yield an in situ grand mean of Declination ( D)=339°, Inclination ( I)=+54°, α95=3.1°, k=27.2, N=81 sites. The rocks of the central core of the volcano yield an in situ grand mean of D=3°, I=+59°, α95=6.8°, k=42.5, N=11 sites (six normal, five reverse polarity). Sites collected within the western Hamblin Lobe of the volcano are exclusively of reverse polarity and yield an overall in situ mean of D=168°, I=-58°, α95=6.5°, k=28.9, N=18 sites. Interpretation of the paleomagnetic data in the context of the structural history of the volcano and surrounding area, considers the possibility of two different types of structural corrections. A stratigraphic tilt correction involves restoring flows to the horizontal using the present strike. This correction assumes no initial, possibly radial, dip of flows of the volcano and is considered invalid. A structural tilt correction to the data assumes that dikes of the radiating swarm associated with the volcano were originally vertical and results in block mean directions of D=9°, I=+53°, α95=3.1°, k=27.2, and D=58°, I=+78°, α95=6.8°, k=42.5, for the Cleopatra Lobe and the central intrusive core, respectively. The data from the Cleopatra Lobe are slightly discordant, in a clockwise sense, from expected middle

  15. Mapping health in the Great Lakes areas of concern: a user-friendly tool for policy and decision makers.

    PubMed Central

    Elliott, S J; Eyles, J; DeLuca, P

    2001-01-01

    The role of the physical environment as a determinant of health is a major concern reported by the general public as well as by many policymakers. However, it remains one of the health determinants for which few available measures or indicators are readily available. This lack of data is compounded by the fact that evidence for direct cause-and-effect relationships in the literature is often equivocal, leading to feelings of uncertainty among the lay public and often leading to indecision among policymakers. In this article we examine one aspect of the physical environment--water pollution in the Great Lakes Areas of Concern (AOCs)--and its potential impacts on a wide range of (plausible) human health outcomes. Essentially, the International Joint Commission, the international agency that oversees Great Lakes water quality and related issues, worked with Health Canada to produce a report for each of the 17 AOCs on the Canadian side of the Great Lakes, outlining a long list of health outcomes and the potential relationships these might have with environmental exposures known or suspected to exist in the Great Lakes basin. These reports are based solely on secondary health data and a thorough review of the environmental epidemiologic literature. The use of these reports by local health policymakers as well as by public health officials in the AOCs was limited, however, by the presentation of vast amounts of data in a series of tables with various outcome measures. The reports were therefore not used widely by the audience for whom they were intended. In this paper we report the results of an undertaking designed to reduce the data and present them in a more policy-friendly manner, using a geographic information system. We do not attempt to answer directly questions related to cause and effect vis-à-vis the relationships between environment and health in the Great Lakes; rather, this work is a hypothesis-generating exercise that will help sharpen the focus of

  16. Relationships between Western Area Power Administration`s power marketing program and hydropower operations at Salt Lake City area integrated projects

    SciTech Connect

    Veselka, T.D.; Folga, S.; Poch, L.A.

    1995-03-01

    This technical memorandum provides background information on the Western Area Power Administration (Western) and the physical characteristics of the Salt Lake City Area Integrated Projects (SLCA/IP) hydropower plants, which include the Colorado River Storage Project, the Rio Grande Project, and the Collbran Project. In addition, the history, electrical capacity, storage capacity, and flow restrictions at each dam are presented. An overview of Western`s current programs and services, including a review of statutory authorities, agency discretion, and obligations, is also provided. The variability of SLCA/IP hourly generation under various alternative marketing strategies and purchasing programs is discussed. The effects of Western`s services, such as area load control, outage assistance, and transmission, on SLCA/IP power plant operations are analyzed.

  17. Issues of scale, location and geologic terrain related to Salt Lake City and Baltimore-Washington metropolitan areas

    USGS Publications Warehouse

    Cleaves, E.T.; Godfrey, A.E.

    2004-01-01

    Planning and development of expanding metropolitan regions require consideration of earth science issues related to issues involving scale, space (location), geologic terrain and physiographic units, and information transfer. This paper explores these matters with examples from the Salt Lake City, Utah area and Mid-Atlantic region of Baltimore-Washington that include water supply and natural hazards (earthquakes, landslides, and sinkholes.) Information transfer methods using physiographic units at national, regional, local and site scales serve to communicate relevant geologic constraint and natural resource information.

  18. Structure, stratigraphy, and depositional environment of the heterostegina limestone and overlying sandstones in the Lake Pontchartrain area of southeast Louisiana

    SciTech Connect

    Street, S.B. III; Lock, B.E.

    1994-12-31

    The Heterostegina zone of the Oligocene Anahuac Formation in southwestern Louisiana occurs in the subsurface as an extensive shelf reef complex. The Heterostegina limestone is overlain by strata associated with the Oligocene Discorbis and lower Miocene Robulus (43) biostratigraphic zones. Examination of electric logs and drill cuttings from wells in the Lake Pontchartrain area of southeastern Louisiana reveals the importance of the Heterostegina reef as a paleoenvironmental punctuation marking a significant shift in regional depositional patterns that occurred between the generally transgressive Oligocene seas and the generally regressive Miocene seas. Fauna identified in thin section from the Heterostegina reef interval suggest deposition in a warm, shallow-marine environment relatively free of significant clastic influx. An eastward migration of late Oligocene-early Miocene stream systems introduced an influx of clastic sediments onto the ancient shelf of the Lake Pontchartrain area, which influenced the termination of favorable conditions for Heterostegina reef growth. Lithofacies I is characterized by thick, shore-parallel sandstone deposits and is interpreted to have been deposited in association with a barrier-beach/tidal-inlet channel environment. Lithofacies II is characterized by shale-prone sandstone intervals, which are immediately overlain by calcareous mudstones and limestones deposited in the offshore inner-middle neritic environment. Five oil and gas fields in the study area have produced hydrocarbons from the interval of interest. The occurrence of hydrocarbons at these locations with respect to mechanisms of entrapment and areal extent of the reservoirs was characterized through detailed subsurface mapping.

  19. Salt Lake City Area Integrated Projects Electric Power Marketing. Draft environmental impact statement: Volume 2, Sections 1-16

    SciTech Connect

    Not Available

    1994-02-01

    The Salt Lake City Area Office of the Western Area Power Administration (Western) markets electricity produced at hydroelectric facilities operated by the Bureau of Reclamation. The facilities are known collectively as the Salt Lake City Area Integrated Projects (SLCA/IP) and include dams equipped for power generation on the Green, Gunnison, Rio Grande, and Colorado rivers and on Deer and Plateau creeks in the states of Wyoming, Utah, Colorado, Arizona, and New Mexico. Of these facilities, only the Glen Canyon Unit, the Flaming Gorge Unit, and the Aspinall Unit (which includes Blue Mesa, Morrow Point, and Crystal dams;) are influenced by Western power scheduling and transmission decisions. The EIS alternatives, called commitment-level alternatives, reflect combinations of capacity and energy that would feasibly and reasonably fulfill Westerns firm power marketing responsibilities, needs, and statutory obligations. The viability of these alternatives relates directly to the combination of generation capability of the SLCA/IP with energy purchases and interchange. The economic and natural resource assessments in this environmental impact statement (EIS) include an analysis of commitment-level alternatives. Impacts of the no-action alternative are also assessed. Supply options, which include combinations of electrical power purchases and hydropower operational scenarios reflecting different operations of the dams, are also assessed. The EIS evaluates the impacts of these scenarios relative to socioeconomics, air resources, water resources, ecological resources, cultural resources, land use, recreation, and visual resources.

  20. Salt Lake City Area Integrated Projects Electric Power Marketing. Draft environmental impact statement: Volume 3, Appendix A

    SciTech Connect

    Not Available

    1994-02-01

    The Salt Lake City Area Office of the Western Area Power Administration (Western) markets electricity produced at hydroelectric facilities operated by the Bureau of Reclamation. The facilities are known collectively as the Salt Lake City Area Integrated Projects (SLCA/IP) and include dams equipped for power generation on the Green, Gunnison, Rio Grande, and Colorado rivers and on Deer and Plateau creeks in the states of Wyoming, Utah, Colorado, Arizona, and New Mexico. Of these facilities, only the Glen Canyon Unit, the Flaming Gorge Unit, and the Aspinall Unit (which includes Blue Mesa, Morrow Point, and Crystal dams;) are influenced by Western power scheduling and transmission decisions. The EIS alternatives, called commitment-level alternatives, reflect combinations of capacity and energy that would feasibly and reasonably fulfill Westerns firm power marketing responsibilities, needs, and statutory obligations. The viability of these alternatives relates directly to the combination of generation capability of the SLCA/IP with energy purchases and interchange. The economic and natural resource assessments in this environmental impact statement (EIS) include an analysis of commitment-level alternatives. Impacts of the no-action alternative are also assessed. Supply options, which include combinations of electrical power purchases and hydropower operational scenarios reflecting different operations of the dams, are also assessed. The EIS evaluates the impacts of these scenarios relative to socioeconomics, air resources, water resources, ecological resources, cultural resources, land use, recreation, and visual resources.

  1. Salt Lake City Area Integrated Projects Electric Power Marketing. Draft environmental impact statement: Volume 4, Appendixes B-D

    SciTech Connect

    Not Available

    1994-02-01

    The Salt Lake City Area Office of the Western Area Power Administration (Western) markets electricity produced at hydroelectric facilities operated by the Bureau of Reclamation. The facilities are known collectively as the Salt Lake City Area Integrated Projects (SLCA/IP) and include dams equipped for power generation on the Green, Gunnison, Rio Grande, and Colorado rivers and on Deer and Plateau creeks in the states of Wyoming, Utah, Colorado, Arizona, and New Mexico. Of these facilities, only the Glen Canyon Unit, the Flaming Gorge Unit, and the Aspinall Unit (which includes Blue Mesa, Morrow Point, and Crystal dams;) are influenced by Western power scheduling and transmission decisions. The EIS alternatives, called commitment-level alternatives, reflect combinations of capacity and energy that would feasibly and reasonably fulfill Westerns firm power marketing responsibilities, needs, and statutory obligations. The viability of these alternatives relates directly to the combination of generation capability of the SLCA/IP with energy purchases and interchange. The economic and natural resource assessments in this environmental impact statement (EIS) include an analysis of commitment-level alternatives. Impacts of the no-action alternative are also assessed. Supply options, which include combinations of electrical power purchases and hydropower operational scenarios reflecting different operations of the dams, are also assessed. The EIS evaluates the impacts of these scenarios relative to socioeconomics, air resources, water resources, ecological resources, cultural resources, land use, recreation, and visual resources.

  2. Volcanic hazard alert issued for the Long Valley-Mono Lake area of California

    USGS Publications Warehouse

    Kerr, R. A.

    1982-01-01

    The ski resort of Mammoth Lakes, nestled against the east front of the Sierra Nevada just east of Yosemite National Park, knows about natural hazards. It is still being shaken by an unusual sequence of earthquakes that started in 1978 and included four earthquakes of magnitude 6 within 48 hours of each other in May 1980. An earthquake hazard watch is still in effect. 

  3. Soil occupation and atmospheric variations over Sobradinho Lake area. Part one: an observational analysis

    NASA Astrophysics Data System (ADS)

    Correia, M. F.; da Silva Dias, M. A. F.; da Silva Aragão, M. R.

    2006-11-01

    Sobradinho Lake lies in the São Francisco River Basin, in one of the most arid regions in Northeastern Brazil, within a land stretch categorized as the Lower-middle São Francisco, situated at about 40 km away from the municipality of Petrolina (09°23'S 40°30'W) in the state of Pernambuco. The dam, in its full capacity, consists of a lake of approximately 4,214 km2; 280 km in length, the width of which varies from 5 to 50 km. The dam storage capacity is that of 34.1 billion m3 of water. Being situated in a semi-arid region, the dam brought about significant development to local irrigated agriculture. The caatinga ecosystem has, for that matter, undergone considerable changes. Statistical analysis techniques applied to data collected before and after the filling of the lake, made it possible both to make an assessment of the impact of the dam construction on the region meteorology and to diagnose the variability of such an impact on environmental conditions. Results showed that the dam has brought about considerable changes to regional meteorology. The alterations were observed to be more significant as regards atmospheric humidity and wind speed.

  4. Spatio-temporal patterns of schistosomiasis japonica in lake and marshland areas in China: the effect of snail habitats.

    PubMed

    Hu, Yi; Gao, Jie; Chi, Meina; Luo, Can; Lynn, Henry; Sun, Liqian; Tao, Bo; Wang, Decheng; Zhang, Zhijie; Jiang, Qingwu

    2014-09-01

    The progress of the integrated control policy for schistosomiasis implemented since 2005 in China, which is aiming at reducing the roles of bovines and humans as infection sources, may be challenged by persistent presence of infected snails in lake and marshland areas. Based on annual parasitologic data for schistosomiasis during 2004-2011 in Xingzi County, a spatio-temporal kriging model was used to investigate the spatio-temporal pattern of schistosomiasis risk. Results showed that environmental factors related to snail habitats can explain the spatio-temporal variation of schistosomiasis. Predictive maps of schistosomiasis risk illustrated that clusters of the disease fluctuated during 2004-2008; there was an extensive outbreak in 2008 and attenuated disease occurrences afterwards. An area with an annually constant cluster of schistosomiasis was identified. Our study suggests that targeting snail habitats located within high-risk areas for schistosomiasis would be an economic and sustainable way of schistosomiasis control in the future. PMID:24980498

  5. Spatio-Temporal Patterns of Schistosomiasis Japonica in Lake and Marshland Areas in China: The Effect of Snail Habitats

    PubMed Central

    Hu, Yi; Gao, Jie; Chi, Meina; Luo, Can; Lynn, Henry; Sun, Liqian; Tao, Bo; Wang, Decheng; Zhang, Zhijie; Jiang, Qingwu

    2014-01-01

    The progress of the integrated control policy for schistosomiasis implemented since 2005 in China, which is aiming at reducing the roles of bovines and humans as infection sources, may be challenged by persistent presence of infected snails in lake and marshland areas. Based on annual parasitologic data for schistosomiasis during 2004–2011 in Xingzi County, a spatio-temporal kriging model was used to investigate the spatio-temporal pattern of schistosomiasis risk. Results showed that environmental factors related to snail habitats can explain the spatio-temporal variation of schistosomiasis. Predictive maps of schistosomiasis risk illustrated that clusters of the disease fluctuated during 2004–2008; there was an extensive outbreak in 2008 and attenuated disease occurrences afterwards. An area with an annually constant cluster of schistosomiasis was identified. Our study suggests that targeting snail habitats located within high-risk areas for schistosomiasis would be an economic and sustainable way of schistosomiasis control in the future. PMID:24980498

  6. The Late Glacial/Holocene transition and its consequences on coastal environment in northwestern Greece (Epirus) : geoarchaeological and palaeogeographical prospects

    NASA Astrophysics Data System (ADS)

    Chabrol, A.; Fouache, E.; Le Coeur, C.; Ghilardi, M.

    2009-04-01

    At the scale of the Mediterranean Basin, the Glacial/Interglacial transition (15 000 - 6 000 BP) corresponds successively to the hunthers-gatherers from the Late Upper Paleolithic societies, to the Mesolithic and then to the farming societies from the Neolithic. The area of research (Epirus and particularly the Ionian coast) reveals original archaeological data: in this area, archaeologists didn't find much prehistoric settlements comparing to other places in Greece. Furthermore, the neolithisation became later than in Thessaly or in Boeotia. Geomorphologic researches and regional palaeogeographical reconstructions should help us to explain the prehistoric human dynamics and the adaptation of these societies to a rapid changing area due in particular to the post glacial sea level rise. The research focuses on Northwestern Epirus: the island of Corfu and the delta of the Kalamas river correspond to a promising area of research. Indeed, this area revealed us different interesting and complementary sedimentary archives for our study: the probable palaeo-lake between Corfu and the continental Greece and the delta of the Kalamas river. The poster for the scientific congress will explain the originality of the area of research and the originality of the geoarchaeological prospects in northwestern Greece. Particularly, the methodology will be explained: archaeological and geomorphologic cartography, geophysical prospection in the delta (electric vertical profiles, seismic profiles) and core sampling activities. Palaeogeographical and geoarchaeological prospects and the first results will be discussed.

  7. Class 1 overview of cultural resources for the Western Area Power Administration Salt Lake City Area Integrated Projects electric power marketing environmental impact statement

    SciTech Connect

    Moeller, K.L.; Malinowski, L.M.; Hoffecker, J.F.; Walitschek, D.A.; Shogren, L.; Mathews, J.E.; Verhaaren, B.T.

    1993-11-01

    Argonne National Laboratory conducted an inventory of known archaeological and historic sites in areas that could be affected by the hydropower operation alternatives under analysis in the power marketing environmental impact statement for the Western Area Power Administration`s Salt Lake City Area Integrated Projects. The study areas included portions of the Green River (Flaming Gorge Dam to Cub Creek) in Utah and Colorado and the Gunnison River (Blue Mesa Reservoir to Crystal Dam) in Colorado. All previous archaeological surveys and previously recorded prehistoric and historic sites, structures, and features were inventoried and plotted on maps (only survey area maps are included in this report). The surveys were classified by their level of intensity, and the sites were classified according to their age, type, and contents. These data (presented here in tabular form) permit a general assessment of the character and distribution of archaeological remains in the study areas, as well as an indication of the sampling basis for such an assessment. To provide an adequate context for the descriptions of the archaeological and historic sites, this report also presents overviews of the environmental setting and the regional prehistory, history, and ethnography for each study area.

  8. Monitoring drying up of Urmia lake with satellite altimetry

    NASA Astrophysics Data System (ADS)

    Roohi, Shirzad; Sneeuw, Nico

    2013-04-01

    Urmia lake is a UNESCO protected area with more than a hundred small rocky islands. It is home to several species of birds and animals. Located in northwestern Iran, it is the largest lake in the Middle East and the third largest salty water lake on earth. It has a surface area of approximately 5200 km², and an average depth of 16 m. Unfortunately during the recently years Urmia lake has been shrinking. If the drought process continues at the current rate it would be disappear in the near future. The main factors that speeds up the drought rate of the lake, are dam construction on the main rivers which feeds the lake, evaporation and lack of precipitation during recent years as well as irrigation. The construction of a causeway in the middle of the lake also affects the natural ecosystem of the lake. The case of Urmia lake and similar cases in other parts of the word emphasize the role of new technology such as satellite altimetry in better management of water resource and monitoring such critical situations. In this research we show the current situation and recent past of the lake from processing 10 years of Envisat satellite radar altimetry data. For internal validation of the result, water level time series were built from ascending and descending tracks separately and for external validation in-situ gauge measurements were used. Internal and external comparisons indicates the result are consistent, i.e there is no bias and systematic error in Envisat data. The RMSE between ascending and descending tracks is several centimeters and between satellite and gauge data is 1m. Water level time series analysis shows that there is a declining rate of 0.3 m/year in the water level but after 2005 it seems to have accelerated. This rate increases the salinity of lake and expands receding shoreline rapidly so the lake bed will reveal fast because the lake is shallow especially in the south part. Following this research we are investigating to find the best re-tracker in

  9. Provenance, age, and environment of mid-Wisconsinan slackwater lake sediment in the St. Louis Metro East area, USA

    NASA Astrophysics Data System (ADS)

    Curry, B. Brandon; Grimley, David A.

    2006-01-01

    Valleys tributary to the Mississippi River contain fossiliferous slackwater lake sediment (Equality Formation) deposited in response to aggradation of the Mississippi River valley during the last glaciation. In the St. Louis Metro East area, the lower part of the Equality Formation is primarily laminated, fossiliferous silt and clay deposited from about 44,150 to 24,310 14C yr B.P. The upper Equality Formation is primarily very fine sand to silt deposited from about 21,200 to 17,000 14C yr B.P. Among the four cores that sample this succession in the St. Louis Metro East area, core MNK-3 (38.64EN, 90.01EW) was selected for detailed study. Three sources are distinguished by the following characteristics: (1) gray smectite-quartz-Se-rich, feldspar-poor material of the Des Moines, Wadena, and James lobes; (2) reddish brown kaolinite-Cu-Fe-rich sediment of the Superior and Rainy lobes; and (3) brown illite-dolomite-Sr-rich sediment of the Lake Michigan and Green Bay lobes. The earliest sediments (44,150 to 41,700 14C yr B.P.) were derived from the central and western provenances and are chronocorrelative with the lower Roxana Silt. A hiatus occurred from about 41,700 to 29,030 14C yr B.P. when much of the middle Roxana Silt (Meadow Member) was deposited on adjacent uplands. The youngest sediment includes evidence of heightened activity of the Superior Lobe at about 29,000 14C yr B.P., the Lake Michigan and Green Bay lobes from about 25,000 to 24,000 14C yr B.P., and the Wadena-Des Moines-James lobes at about 21,000 14C yr B.P.

  10. Numerical simulation of local atmospheric circulations in the pre-Alpine area between Lake Garda and Verona

    NASA Astrophysics Data System (ADS)

    Laiti, L.; Serafin, S.; Zardi, D.

    2010-09-01

    The pre-Alpine area between Lake Garda and Verona displays a very complex and heterogeneous territory, allowing the development of several interacting systems of thermally driven local winds, the major being the lake/land breeze system on the coasts of Lake Garda and the up/down-valley wind system between the plain and the river Adige Valley. In order to investigate the local wind patterns, a series of nested numerical simulations with a horizontal resolution of 500 m were carried out using the ARPS 5.2.9 model (Xue et al. 2000, 2001), considering a fair weather day suitable for a clear development of the expected circulations (15th July 2003). The simulated wind speed and direction, pressure, temperature and water vapour mixing ratio were compared to synoptic scale meteorological charts, to vertical profiles from radiosoundings taken at the major sounding stations of the alpine region and to local scale measurements performed at the surface station of Dolcè (at the inlet of the Adige Valley). Numerical results at all scales were found to be in very good agreement with the available sets of meteorological observations. The analysis of the diurnal evolution of the 3D fields of temperature, moisture content, wind and turbulent kinetic energy allowed the identification of a very shallow and clearly defined breeze front of cold and humid air moving from off-shore towards the Lake Garda coast, from the late morning (10:00 LST) until the evening (20:00 LST). The diurnal up-valley breeze was also well reproduced: the valley atmosphere displays a thick mixed layer dominated by shallow turbulent convection between 11:00 LST and 21:00 LST. Lateral slope winds were also recognized, as they created cross-valley convective cells. While no clear evidence of a nocturnal land breeze was found in the simulations, the nocturnal down-valley wind in the Adige Valley was clearly reproduced. Finally, a scalar transport equation was added to the ARPS model in order to simulate transport

  11. [Ecotourism exploitation model in Bita Lake Natural Reserve of Yunnan].

    PubMed

    Yang, G; Wang, Y; Zhong, L

    2000-12-01

    Bita lake provincial natural reserve is located in Shangri-La region of North-western Yunnan, and was set as a demonstrating area for ecotourism exploitation in 1998. After a year's exploitation construction and half a year's operation as a branch of the 99' Kunming International Horticulture Exposition to accept tourists, it was proved that the ecotourism demonstrating area attained four integrated functions of ecotourism, i.e., tourism, protection, poverty clearing and environment education. Five exploitation and management models including function zoned exploitation model, featured tourism communication model signs system designing model, local Tibetan family reception model and environmental monitoring model, were also successful, which were demonstrated and spreaded to the whole province. Bita lake provincial natural reserve could be a good sample for the ecotourism exploitation natural reserves of the whole country. PMID:11767581

  12. Peralkaline silicic volcanic rocks in northwestern nevada.

    PubMed

    Noble, D C; Chipman, D W; Giles, D L

    1968-06-21

    Late Tertiary silicic ashflow tuffs and lavas peralkaline in chemical character (atomic Na + K greater than Al), mainly comendites, occur over wide areas in northwestern Nevada and appear to be widespread in southeastern Oregon. Such peralkaline rocks-which are not uncommon in the western United States-and other chemically unusual silicic rocks are found near the margins rather than toward the center of the Great Basin. PMID:17800671

  13. Acid-induced changes in DOC quality in an experimental whole-lake manipulation

    SciTech Connect

    Donahue, W.F.; Schindler, D.W.; Page, S.J.; Stainton, M.P.

    1998-10-01

    Fluorescence analyses of archived water samples were used to typify dissolved organic carbon (DOC) quality in experimentally acidified lakes and reference lakes at the Experimental Lakes Area, in northwestern Ontario. Carbon-specific DOC fluorescence (CSF) during peak acidification was 40--50% of that for a high-DOC reference lake and similar to a low-DOC reference lake. Reference lakes showed similar but smaller decreases in CSF during several years of prolonged drought in the late 1980s. During the 1990s, recovery from acidification resulted in increased CSF, whereas reference lakes remained unchanged during the same time period. In addition to causing decreased [DOC], acidification causes changes in fluorescence-peak geometry that indicate a switch in DOC quality from allochthonous to autochthonous-like during acidification. The acid-induced change in DOC quality was likely due to increased chemical oxidation or precipitation of the UV-absorbent aromatic portions of allochthonous DOC molecules, leaving more UV-transparent aliphatic chains. The change in the nature of DOC following acidification and drought may have an important role in physical, biological, and chemical processes within these lakes. With recovery from acidification, DOC quality has also recovered.

  14. Pathogenesis of skin and liver neoplasms in white suckers from industrially polluted areas in Lake Ontario.

    PubMed

    Hayes, M A; Smith, I R; Rushmore, T H; Crane, T L; Thorn, C; Kocal, T E; Ferguson, H W

    1990-05-01

    Increased prevalences of epidermal and hepatobiliary neoplasms in white suckers (Catostomu commersoni) and brown bullheads (Ictalurus nebulosus) in the Western region of Lake Ontario have been associated with industrial pollution, but the identity and causative role of environmental carcinogens have not yet been established. Most epidermal tumors of lip and body skin are benign focal proliferations that occur in fish from the polluted Hamilton region, and also in fish from less polluted sites in the Great Lakes. These skin tumors in white suckers do not have consistent alterations in cellular glutathione S-transferases (GST), suggesting that growth of skin tumors is not promoted by chemicals normally detoxified by GST. However, elevated levels of glutathione peroxidase (GPO) and glutathione reductase (GR) in skin papillomas are indicative of promotional peroxidative tissue injury, either caused directly by xenobiotics or indirectly by chemical-induced inflammation. Liver tumors in white suckers from Lake Ontario include preneoplastic, benign, and malignant populations of hepatocellular and biliary cells, all of which are more prevalent in fish from polluted sites. These liver tumors are consistently associated with chronic cholangiohepatitis and segmental cholangiofibrosis, but these conditions also occur in white suckers in non-industrial locations. Thus, the natural occurrence of biliary disease, not attributable to industrial pollution, may have some influence on the development of liver tumors. Some preneoplastic lesions and the majority of neoplastic hepatocellular and biliary lesions in white suckers have low levels of total GST, indicating that these liver neoplasms are not promoted by xenobiotics normally detoxified by hepatic GSTs.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2360036

  15. Aeromagnetic interpretation and mineral investigations in the Bolu, Canakkale-Karabiga, Demirkoy, Ezine, and Orhaneli areas of northwestern Turkey in 1968

    USGS Publications Warehouse

    Jacobson, Herbert Samuel; Tumer, Ural; Karahacioglu, Hamit

    1972-01-01

    This report reviews progress made during 1968 in the continuing Joint Haden Tetkik ve Arama Enstitusu (MSA)-U. S. Geological Survey (USGS) Mineral Exploration and Training Project, Subproject 2. Subproject 2 is concerned with aeromagnetic interpretation of MTA's aeromagnetic surveys, and ground investigations of selected aeromagnetic anomalies. This report includes new aeromagnetic maps for the Bolu, Canakkale-Karabiga, Demirkoy, and Orhaneli areas and reviews ground investigations in five areas. Activities for each area are sunmarized below: 1. Bolu area: The aeromagnetic map shows two belts of anomalies related to regional magnetite-bearing formations and a group of discrete anomalies, some of which may reflect significant concentrations of magnetite. To date three of these anomalies have been checked on the ground and at one a metamorphic rock containing 14 percent magnetite was observed. 2. Canakkale-Karabiga area: Ground checks were made of six aeromagnetic anomalies. At one locality (Cakirly-Koyu) 6 km south of Nazmara Sea a small magnetite deposit was found. The magnetic anomaly over the area is 150 meters long, and about 3 meters deep in the center of the anomaly exposed massive magnetite boulders. 3. Demirkoy area: The aeromagnetic map shows only one significant anomaly which was checked on the ground and found to be caused by minor magnetite at an intrusive contact. 4. Ezine area: A ground survey of 4.5 sq km area was made where magnetite boulders are locally present on the surface. No significant magnetic anomaly or iron mineralization were found. 5. Orhaneli area: The aeromagnetic map o# the area showed regional magnetic anomaly patterns related to magnetite in mafic intrusives, ultramafic rocks, and mafic flow rocks. In addition 16 localized anomalies were identified. Most of these anomalies were checked on the ground but no significant iron deposits were found. The largest deposit found was a one-meter wide magnetite vein. During the 1969 field season

  16. Lawsonite eclogites from the Pinchi Lake area, British Columbia—new P- T estimates and interpretation

    NASA Astrophysics Data System (ADS)

    Ghent, Edward; Tinkham, Douglas; Marr, Robert

    2009-05-01

    Lawsonite eclogites from Pinchi Lake, British Columbia, occur as tectonic blocks associated with lawsonite, aragonite, and jadeite-bearing blueschists. One tectonic block from Tezzeron Lake shows extensive lower-temperature retrogression. The block from Beaver Lake Road (BLR) shows less retrogression and the garnet crystals contain abundant inclusions of lawsonite and omphacite suggesting these minerals were stable throughout most of the crystallization history. Compositional profiles and element maps of garnets show: (1) Mn enrichment in cores with decrease toward rims; (2) little change in Ca from core to rim; (3) general decrease in Fe/Mg from core to rim. Phase diagram sections for sample BLR-3 and garnet-core compositions suggest garnet-core growth at 505 °C and 24.3 kbar (1 kbar = 0.1 GPa). Temperature estimates based upon garnet-clinopyroxene Fe-Mg exchange geothermometry are, for inclusions in garnet at 25 kbar, 450 ± 30 °C (4 spots); 435 ± 15 (10); and 445 ± 25 (6). For garnet rims and matrix clinopyroxene the results are: 515 ± 50 °C (2); 440 ± 25 (5); 475 ± 20 (2). These results suggest very little if any statistically significant changes in temperature during crystal growth. Estimates of pressure are based upon several different calibrations of the garnet-clinopyroxene-phengite equilibria. Using the calibration of Krogh-Ravna we obtain pressures of: 24.2-26.8 kbar, compatible with that estimated for garnet-core growth in BLR-3. For the glaucophane = talc + jadeite geobarometer, the activity relations for glaucophane are not well constrained. At 450 °C a pressure of 26 kbar is calculated (one sample). A pressure of 25 kbar at 450 °C suggests depths of ~ 90 km, leading to a P- T gradient of ~ 5 °C km - 1 . This gradient passes through the inferred stability field of lawsonite eclogites and the calculated stability fields of lawsonite for Pinchi Lake samples. This is very near the P- T stability field of coesite, which is characteristic of

  17. Lake Volta, Ghana

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image of Lake Volta in Ghana was acquired March 31, 2002 by the Moderate Resolution Imaging Spectroradiometer (MODIS). Lake Volta is one of the world's largest artificially created lakes. Lake Volta is actually a reservoir formed from the damming of the Volta River, and extends 250 miles north of the Akosombo Dam. The lake covers an area of 8,482 square km. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  18. Hydrogeologic framework and geologic structure of the Floridan aquifer system and intermediate confining unit in the Lake Okeechobee area, Florida

    USGS Publications Warehouse

    Reese, Ronald S.

    2014-01-01

    The successful implementation of aquifer storage and recovery (ASR) as a water-management tool requires detailed information on the hydrologic and hydraulic properties of the potential water storage zones. This report presents stratigraphic and hydrogeologic sections of the upper part of the Floridan aquifer system and the overlying confining unit or aquifer system in the Lake Okeechobee area, and contour maps of the upper contacts of the Ocala Limestone and the Arcadia Formation, which are represented in the sections. The sections and maps illustrate hydrogeologic factors such as confinement of potential storage zones, the distribution of permeability within the zones, and geologic features that may control the efficiency of injection, storage, and recovery of water, and thus may influence decisions on ASR activities in areas of interest to the Comprehensive Everglades Restoration Plan.

  19. Organic toxicants in air and precipitation samples from the Lake Michigan area

    SciTech Connect

    Harlin, K.S.; Sweet, C.W.; Gatz, D.F.

    1995-12-31

    Measurements of PCBs, organochlorine insecticides, PAHs, and atrazine were made in air and precipitation samples collected at regionally-representative locations near Lake Michigan from 1992-1995. The purpose of these measurements was to provide information needed to estimate the atmospheric deposition of organic toxicants to Lake Michigan. Twenty-four hour samples of airborne particles and vapor were collected at 12-day intervals on quartz fiber filters and XAD-2 resin vapor traps using modified high volume sampleers. Twenty-eight day precipitation samples were collected using wet-only samplers with stainless steel sampling surfaces and heated enclosure containing an XAD-2 resin adsorption column. Samples were Soxhlet extracted for 24 hours with hexane:acetone (1:1), and concentrated by rotary evaporation. Interferences were removed and the samples separated into analyte groups by silica gel chromatography. Four fractions were collected for GC-ECD and GC-Ion Trap MS analyses. Ten pesticides, 101 PCB congeners, 18 PAHs, and atrazine were measured in all samples. Quality assurance was maintained by including field duplicate samples, field blanks, alboratory matrix spikes, laboratory matrix blanks, and laboratory surrogate spikes in the sampling/analytical protocols. Preliminary results from urban and remote sites show geographical variations in the concentrations of some toxicants due to contributions from local sources. For all sites the total PCB levels are higher in the vapor phase than the particulate phase and show strong seasonal variations. Seasonal variations were also observed for several pesticides.

  20. Environmental geophysics and sequential aerial photo study at Sunfish and Marsden Lakes, Twin Cities Army Ammunition Plant

    SciTech Connect

    Padar, C.A.; McGinnis, L.D.; Thompson, M.D.; Anderson, A.W.; Benson, M.A.; Stevanov, J.E.; Daudt, C.R.; Miller, S.F.; Knight, D.E. |

    1995-08-01

    Geophysical studies at Site H of Twin Cities Army Ammunition Plant have delineated specific areas of dumping and waste disposal. Anomalous areas noted in the geophysical data sets have been correlated with features visible in a chronological sequence of aerial photos. The photos aid in dating the anthropogenic changes and in interpreting the geophysical anomalies observed at Site H and across Sunfish Lake. Specifically, two burn cages and what has been interpreted as their surrounding debris have been delineated. The areal extent of another waste site has been defined in the southwest corner of Area H-1. Depth estimates to the top of the Area H-1 anomalies show that the anomalies lie below lake level, indicative of dumping directly into Sunfish Lake. Except for these areas along the northwestern shore, there is no evidence of waste disposal along the shoreline or within the present-day lake margins. Magnetic, electromagnetic, and ground-penetrating-radar data have pinpointed the locations of mounds, observable in aerial photos, around the first burn cage. The second burn cage and its surrounding area have also been clearly defined from aerial photos, with support from further geophysical data. Additional analysis of the data has yielded volumetric estimates of the amount of material that would need removal in the event of excavation of the anomalous areas. Magnetic and electromagnetic profiles were also run across Marsden Lake. On the basis of these data, it has been concluded that no large-scale dumping has occurred in or around Marsden Lake.

  1. Geohydrology, water quality, and water budgets of Golden Gate Park and the Lake Merced area in the western part of San Francisco, California

    USGS Publications Warehouse

    Yates, E.B.; Hamlin, S.N.; McCann, L.H.

    1990-01-01

    The groundwater resources in the western part of the San Francisco, groundwater budgets for Golden Gate Park and the Lake Merced area, and a surface-water budget for Lake Merced are described. A continuous groundwater basin underlies a 39-sq-mi coastal strip in the San Francisco Peninsula south of the city. Basin fill consists largely of sand and silt. An extensive subsurface clay layer is present near Lake Merced. Recharge is principally from rainfall and irrigation-return flow, with lesser amounts from leaking water and sewer pipes, which were identified in part by stable-isotope and major ion analyses. In Golden Gate Park, about 1, 070 acre-ft/yr of groundwater flows to the ocean. Water levels are not declining, and pumpage could be safely increased. However, nitrate concentrations in excess of Federal drinking-water standards in water from many wells may limit potential uses of groundwater. Groundwater in the Lake Merced area is in a state of overdraft, as indicated by long- term declines in the level of Lake Merced and by groundwater levels persistently below sea level in deep wells. Seawater intrusion has not been detected, however. A surface-water budget for Lake Merced indicates that the largest inflow is from shallow groundwater and the largest outflow is loss by evaporation. (USGS)

  2. Land use changing and land use optimization of Lake Baikal basin on the example of two key areas

    NASA Astrophysics Data System (ADS)

    Solodyankina, S.

    2012-04-01

    Lake Baikal contains roughly 20% of the world's unfrozen surface fresh water. It was declared a UNESCO World Heritage Site in 1996. Today levels of urbanization and economic stress on environmental resources is increasing on the shorts of the lake Baikal. The potential of economic development (industry, local tourism, and mining) of the Severobaykalsky and Sludyansky districts is rather high although they are characterized not only by beneficial features for local economy but also by considerable disadvantages for nature of this world valuable territory. This investigation show human-caused landscape changes during economic development of the two key areas in Baikal water catchment basin during 10 years (point of reference is 2000 year). Key areas are 1) the Baikalo-Patomskoe highland in the north of the Baikal catchment basin (Severobaykalsky district, Republic of Buryatia); 2) Khamar-Daban mountain system in the south of the Baikal catchment basin (Sludyansky districy, Irkutsk region). Since 2000 year land use of the territory has changed. Areas of agriculture were reduced but recreation activity on the bank of the lake was increased. Methods of GIS analysis and local statistic analysis of landscape characteristic were used. Nature, rural and urban areas ratio are estimated. Vegetation and soil condition assessment were made. The essence of this research is in helping to make decisions linked to upcoming problems: situation identification, evaluation and forecasting of the potential landscape condition, optimization of land use, mitigation of impact and mapping of territories and nature resources which have a high ecological value or endangered by industrial impact. For this purpose landscape maps of the territories on the base of the remote sensing information and field investigations were created. They used to calculate potential landscape functions of the territory without taking into account present impact of anthropogenic actions. Land use maps for years

  3. Lake Effect Clouds

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The lake effect is particularly clear in this Sea-viewing Wide field-of-view Sensor (SeaWiFS) true-color image of the North American Great Lakes region, acquired December 5, 2000. Lakes Nipigon, Superior, and Michigan show striking contrasts between clear and cloudy air as the wind blows from the northwest across the lakes. As it flows across the relatively warm lakes, the cold dry air gathers heat and moisture from the surface. The warm moist air rises into the atmosphere and mixes vigorously with the cold dry air above. The layer of warm moist air deepens as it travels across the lake. Some of the evaporated water from the lake condenses into streamers of fog rising from the surface, while much of the moisture condenses to form a stratocumulus cloud in the upper half of the mixed layer. The cloud-forming water droplets may freeze into ice crystals and, due to accumulated water deposition over time, grow into snowflakes. This process can generate snowstorms that produce significant amounts of snowfall downwind. It is not uncommon for lake effect snowstorms to produce as much as two feet of snow within a 24-hour period in northwestern parts of New York and Pennsylvania. Image provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  4. Distribution and geochemistry of contaminated subsurface waters in fissured volcanogenic bed rocks of the Lake Karachai Area, Chelyabinsk, Southern Urals

    SciTech Connect

    Solodov, I.N.; Belichkin, V.I.; Zotov, A.V.; Kochkin, B.T.; Drozhko, E.G.; Glagolev, A.V.; Skokov, A.N.

    1994-06-01

    The present investigation is devoted to the study of the distribution and geochemistry of contaminated subsurface waters, beneath the site of temporary storage of liquid radioactive waste known as Lake Karachai. For this purpose a method of hydrogeochemical logging (HGCL) together with standard hydrogeochemical and geophysical methods of uncased hole logging were used. The distribution of sodium nitrate brine plumes in the subsurface was determined by the physical and physico-chemical properties of these brines and by the petrochemical composition of enclosing rocks and the structural setting of the flow paths. The latter is represented by fractures and large faults in the bedrock of volcanogenic and volcanogenic-sedimentary rocks of intermediate-to-basic composition. The volcanogenic rocks are overlain in some places by a thin cover of unconsolidated sediments, i.e., by loams and relatively impermeable silts. Contaminated waters flow-in accordance with the eluvium bottom relief towards local areas of natural (Mishelyak and Techa rivers) and artificial (Novogomenskii water intake) discharge of subsurface waters. The large Mishelyak fault, southwest of Lake Karachai and under fluvial sediments of the Mishelyak, is assumed to significantly influence the flow pattern of contaminated waters, diverting them from an intake of drinking water.

  5. Use of Landsat Land Surface Temperature and Vegetation Indices for Monitoring Drought in the Salt Lake Basin Area, Turkey

    PubMed Central

    Orhan, Osman; Ekercin, Semih; Dadaser-Celik, Filiz

    2014-01-01

    The main purpose of this paper is to investigate multitemporal land surface temperature (LST) changes by using satellite remote sensing data. The study included a real-time field work performed during the overpass of Landsat-5 satellite on 21/08/2011 over Salt Lake, Turkey. Normalized vegetation index (NDVI), vegetation condition index (VCI), and temperature vegetation index (TVX) were used for evaluating drought impact over the region between 1984 and 2011. In the image processing step, geometric and radiometric correction procedures were conducted to make satellite remote sensing data comparable with in situ measurements carried out using thermal infrared thermometer supported by hand-held GPS. The results showed that real-time ground and satellite remote sensing data were in good agreement with correlation coefficient (R2) values of 0.90. The remotely sensed and treated satellite images and resulting thematic indices maps showed that dramatic land surface temperature changes occurred (about 2°C) in the Salt Lake Basin area during the 28-year period (1984–2011). Analysis of air temperature data also showed increases at a rate of 1.5–2°C during the same period. Intensification of irrigated agriculture particularly in the southern basin was also detected. The use of water supplies, especially groundwater, should be controlled considering particularly summer drought impacts on the basin. PMID:24587709

  6. Use of Landsat land surface temperature and vegetation indices for monitoring drought in the Salt Lake Basin Area, Turkey.

    PubMed

    Orhan, Osman; Ekercin, Semih; Dadaser-Celik, Filiz

    2014-01-01

    The main purpose of this paper is to investigate multitemporal land surface temperature (LST) changes by using satellite remote sensing data. The study included a real-time field work performed during the overpass of Landsat-5 satellite on 21/08/2011 over Salt Lake, Turkey. Normalized vegetation index (NDVI), vegetation condition index (VCI), and temperature vegetation index (TVX) were used for evaluating drought impact over the region between 1984 and 2011. In the image processing step, geometric and radiometric correction procedures were conducted to make satellite remote sensing data comparable with in situ measurements carried out using thermal infrared thermometer supported by hand-held GPS. The results showed that real-time ground and satellite remote sensing data were in good agreement with correlation coefficient (R2) values of 0.90. The remotely sensed and treated satellite images and resulting thematic indices maps showed that dramatic land surface temperature changes occurred (about 2°C) in the Salt Lake Basin area during the 28-year period (1984-2011). Analysis of air temperature data also showed increases at a rate of 1.5-2°C during the same period. Intensification of irrigated agriculture particularly in the southern basin was also detected. The use of water supplies, especially groundwater, should be controlled considering particularly summer drought impacts on the basin. PMID:24587709

  7. Structure, stratigraphy, and depositional environment of the Heterostegina limestone and overlying sands in the Lake Pontchartrain Area of southeast Louisiana

    SciTech Connect

    Street, S.B. III

    1994-09-01

    The Heterostegina zone of the Oligocene Anahuac Formation in southeastern Louisiana occurs in the subsurface as an extensive shelf reef complex. The Heterostegina limestone is overlain by strata associated with the Oligocene Discorbis and lower Miocene Robulus (43) biostratigraphic zones. Examination of electric logs and drill cuttings from wells in the Lake Pontchartrain area of southeastern Louisiana reveal the importance of the Heterostegina reef as a paleoenvironmental punctuation marking a significant shift in regional depositional patterns that occurred between the generally transgressive Oligocene seas and the generally regressive Miocene seas. Fauna identified in thin section from the Heterostegina reef interval suggest deposition in a warm, shallow marine environment relatively free of significant elastic influx. An eastward migration of late Oligocene-early Miocene stream systems introduced an influx of elastic sediments onto the ancient shelf of the Lake Pontchartrain area, which influenced the termination of favorable conditions for Heterostegina reef growth. The Robulus (43) zone strata are characterized by a cyclic sequence of lime, shale, and sand. Within this interval, two general lithofacies are identified. Lithofacies I is characterized by thick, shore-parallel sand deposits, and is interpreted to have been deposited in association with a barrier-beach/tidal-inlet channel environment. Lithofacies II is characterized by shaleprone sand intervals, which are immediately overlain by calcareous shales and limestones deposited in the offshore inner-middle neritic environment. Five oil and gas fields in the study area have produced hydrocarbons from the interval of interest. The occurrence of hydrocarbons at these locations with respect to mechanisms of entrapment and areal extent of the reservoirs is characterized through detailed subsurface mapping.

  8. Multy-proxy reconstruction of climate and environment on the Karelian Isthmus, northwestern Russia

    NASA Astrophysics Data System (ADS)

    Syrykh, Ludmila; Nazarova, Larisa; Frolova, Larissa; Drosenko, Dmitry; Subetto, Dmitry

    2014-05-01

    The Karelian Isthmus is the approximately 45-110 km wide stretch of land, situated between the Gulf of Finland and Lake Ladoga in the Northwestern Russia, to the north of the River Neva (between 61°21'N, 59°46'N and 27°42'E, 31°08'E). Its northwestern boundary is the relatively narrow area between the Bay of Vyborg and Lake Ladoga. The Karelian Isthmus, can be divided into three landscape units: the lowland area in the north with more than 800 lakes; the central highland, which reaches up to 203 m a.s.l.; and the Neva Lowland (15-25 m a.s.l.) in the south, which is characterized by numerous Holocene terraces. The region has a maritime climate, with mean January temperatures of -9°C, mean July temperatures of +16°C and a mean annual temperature of +3°C. Precipitation is around 600 mm yr-1. Sediments were retrieved from the Lake Medvedevskoye (60°13'N; 29°54'E), Karelian Isthmus, and were subject to multy-ptoxy analysis. For the first time quantitative reconstruction of T July was performed, using chironomid-based inference model (Nazarova et al., 2014). The studied lake basin formed before 12,650 cal. yrs BP, possibly due to melting of stagnant glacier ice (Subetto et al., 2002, 2003). Although the chronology of this early part of the record is too uncertain to attribute an exact age to the beginning of minerogenic sedimentation in the basins, it is likely that the sediments accumulated fairly rapidly. Shrub, herb and grass communities ('steppe-tundra') and cold and dry climatic conditions dominated in the area until about 11 000 cal. yrs BP. The rapid environmental response to warming at the Pleistocene/Holocene boundary, which is evident in many North Atlantic records at c. 11 500 cal. yrs BP, is not very prominent in our two data sets from the Karelian Isthmus about 10000 cal. yrs BP when climate became distinctly warmer and more humid. High organic productivity in the lakes indicates that soils around the lakes were stable. The delayed response of the

  9. Ground motion measurement in the Lake Mead area, Nevada, by differential synthetic aperture radar interferometry time series analysis: Probing the lithosphere rheological structure

    NASA Astrophysics Data System (ADS)

    Cavalié, O.; Doin, M.-P.; Lasserre, C.; Briole, P.

    2007-03-01

    We measure ground motion around the Lake Mead, Nevada, using synthetic aperture radar interferometry. The lake water level has fluctuated through time since impoundment in 1935. To quantify the deformation due to water level variations over the past decade, and to constrain the crust and mantle rheological parameters in the lake area, we analyze 241 interferograms based on 43 ERS images acquired between 1992 and 2002. All interferograms have a high coherence due to arid conditions. Most of them show strong atmospheric artefacts. Tropospheric phase delays are estimated and corrected for each interferogram by analyzing the phase/elevation correlation. Corrections are validated using data from the ERA40 global atmospheric reanalysis. Corrected interferograms are inverted pixel by pixel to solve for the time series of ground motion in the lake area. Temporal smoothing is added to reduce random atmospheric artefacts. The observed deformation is nonlinear in time and spreads over a 50 × 50 km2 area. We observe a 16 mm subsidence between 1995 and 1998 due to an 11 m water level increase, followed by an uplift due to the water level drop after 2000. We model the deformation, taking into account the loading history of the lake since 1935. A simple elastic model with parameters constrained by seismic wave velocities does not explain the amplitude of the observed motion. The two-layer viscoelastic model proposed by Kaufmann and Amelung (2000), with a mantle viscosity of 1018 Pa s, adjusts well the data amplitude and its spatiotemporal shape.

  10. Cutaneous and post kala-azar dermal leishmaniasis caused by Leishmania infantum in endemic areas of visceral leishmaniasis, northwestern Iran 2002–2011: a case series

    PubMed Central

    Badirzadeh, Alireza; Mohebali, Mehdi; Ghasemian, Mehrdad; Amini, Hassan; Zarei, Zabiholah; Akhoundi, Behnaz; Hajjaran, Homa; Emdadi, Dariush; Molaei, Soheila; Kusha, Ahmad; Alizadeh, Saber

    2013-01-01

    Visceral leishmaniasis (VL) is endemic in Northwest and southern Iran. Reports of cutaneous leishmaniasis (CL) in Northwest areas are rare, and its etiological agents are unknown. In the current study, we report six CL and two post kala-azar dermal leishmaniasis (PKDL) cases caused by Leishmania infantum from endemic areas of VL in the Northwest. Smears were made from skin lesions of 30 suspected patients in 2002–2011, and CL was determined by microscopy or culture. Leishmania spp. were identified by nested-PCR assay. The disease was confirmed in 20 out of 30 (66%) suspected patients by parasitological examinations. L. infantum was identified in eight and Leishmania major in 12 CL cases by nested-PCR. Cutaneous leishmaniasis patients infected with L. major had the history of travel to CL endemic areas. L. infantum antibodies were detected by direct agglutination test (DAT) at titers of 1:3200 in two cases with history of VL. Results of this study indicated that L. infantum is a causative agent of CL as well as PKDL in the VL endemic areas. PMID:23816511

  11. Coal deposits of the Hedstrom Lake area, McCone, Garfield, Prairie, Custer, and Rosebud counties, Montana

    USGS Publications Warehouse

    Wincentsen, Herbert

    1979-01-01

    The Hedstrom Lake area is located on the southwestern flank of the Williston basin, which is a major structural feature in eastern Montana and western North Dakota. Locally, the rocks have a structural high in T. 12 N., R. 47 E., a structural low in T. 18 N., R. 46 E., and a maximum structural relief of more than 700 ft. The exposed rocks in most of the area are part of the Tongue River Member of the Paleocene Fort Union Formation. The Tongue River Member consists of interbedded siltstone, sandstone, shale, and coal. In ascending order, the five main or principal coal beds are the S, Haughins, R, Q, and Rogers. The S bed ranges in thickness from 0 to 11 ft. The Haughins bed is usually a single bed 2-10 ft thick; in the southern part of the area, it splits into two benches which have a total thickness of 12 ft. The R bed is thin in most of the area, but in the northern part it attains a thickness of 9 ft.. The Q bed occurs at about the same horizon as the Rogers bed, but the drilling control and surface mapping are insufficient for correlation. The Rogers bed has a maximum thickness of 17.1 ft in sec. 15, T. 13N., R. 47 E., but thins rapidly to the northwest.

  12. A historical perspective on the "fish tumors or other deformities" beneficial use impairment at Great Lakes Areas of Concern

    USGS Publications Warehouse

    Rafferty, S.D.; Blazer, V.S.; Pinkney, A.E.; Grazio, J.L.; Obert, E.C.; Boughton, L.

    2009-01-01

    The Great Lakes Water Quality Agreement defines Areas of Concern as geographic areas that fail to meet the general or specific objectives of the agreement where such failure has caused or is likely to cause impairment of beneficial use of the area's ability to support aquatic life. One of the beneficial use impairments, fish tumors or other deformities, is defined by the International Joint Commission to occur when the incidence rate of fish tumors and other deformities exceeds rates at unimpacted or control sites, or when survey data confirm the presence of neoplastic or preneoplastic liver tumors in bullhead or suckers. Brown bullhead, a benthic species with a limited home range, have frequently been used as indicator species in U.S. Areas of Concern. While there is strong field evidence for an association between PAH exposure and hepatic neoplasia in brown bullhead, laboratory investigations would strengthen the association. There is less evidence linking specific classes of chemicals in the environment to orocutaneous neoplasia in brown bullhead. Studies on orocutaneous neoplasia of brown bullhead should focus on assessing the presence or absence of viruses and on epidermal exposure to specific chemicals and chemical mixtures. Lastly, the effects of covariates such as length, age, and gender on the prevalence of liver and skin neoplasms should be investigated. This paper reviews the state of science on the fish tumors or other deformities beneficial use impairment. Subsequent papers address specific issues related to this impairment and provide recommendations for standardized criteria.

  13. Assessing surface water quality and its relation with urban land cover changes in the Lake Calumet area, Greater Chicago.

    PubMed

    Wilson, Cyril; Weng, Qihao

    2010-05-01

    Urban land use and land cover change significantly affect spatial and temporal patterns of runoff, which in turn impacts surface water quality. With the exponential growth in urban areas over the past three decades, changes in land use and land cover to cater for the growth of cities has been a conspicuous spectacle in urban spaces. The main goal of this study was to assess the impacts of land cover change on runoff and surface water quality using a partial area hydrology framework. The study employed ArcHydro GIS extension and a modified version of Long-Term Hydrologic and Nonpoint Source Pollution model (L-THIA-NPS) in estimating runoff and nonpoint source pollutant concentration around Lake Calumet between 1992 and 2001. Data employed include National Land Cover Data set, rainfall data, digital elevation model (DEM), Soil Survey Geographic (SSURGO) data, and The United States Environmental Protection Agency's STORET (storage and retrieval) water quality data. The model was able to predict surface water quality reasonably well over the study period. Sensitivity analysis facilitated a manual calibration of the model. Model validation was executed by comparing simulated results following calibration and observed water quality data for the study area. The study demonstrates that the level of concentration of nonpoint source pollutants in surface water within an urban watershed heavily depends on the spatiotemporal variations in areas that contribute towards runoff compared to the spatial extent of change in major land use/land cover. PMID:20364379

  14. Assessing Surface Water Quality and Its Relation with Urban Land Cover Changes in the Lake Calumet Area, Greater Chicago

    NASA Astrophysics Data System (ADS)

    Wilson, Cyril; Weng, Qihao

    2010-05-01

    Urban land use and land cover change significantly affect spatial and temporal patterns of runoff, which in turn impacts surface water quality. With the exponential growth in urban areas over the past three decades, changes in land use and land cover to cater for the growth of cities has been a conspicuous spectacle in urban spaces. The main goal of this study was to assess the impacts of land cover change on runoff and surface water quality using a partial area hydrology framework. The study employed ArcHydro GIS extension and a modified version of Long-Term Hydrologic and Nonpoint Source Pollution model (L-THIA-NPS) in estimating runoff and nonpoint source pollutant concentration around Lake Calumet between 1992 and 2001. Data employed include National Land Cover Data set, rainfall data, digital elevation model (DEM), Soil Survey Geographic (SSURGO) data, and The United States Environmental Protection Agency’s STORET (storage and retrieval) water quality data. The model was able to predict surface water quality reasonably well over the study period. Sensitivity analysis facilitated a manual calibration of the model. Model validation was executed by comparing simulated results following calibration and observed water quality data for the study area. The study demonstrates that the level of concentration of nonpoint source pollutants in surface water within an urban watershed heavily depends on the spatiotemporal variations in areas that contribute towards runoff compared to the spatial extent of change in major land use/land cover.

  15. Evaporation from a small prairie wetland in the Cottonwood Lake Area, North Dakota - An energy-budget study

    USGS Publications Warehouse

    Parkhurst, R.S.; Winter, T.C.; Rosenberry, D.O.; Sturrock, A.M.

    1998-01-01

    Evaporation from Wetland Pl in the Cottonwood Lake area of North Dakota, USA was determined by the energy-budget method for 1982-85 and 1987. Evaporation rates were as high as 0.672 cm day-1. Incoming solar radiation, incoming atmospheric radiation, and long-wave radiation emitted from the water body are the largest energy fluxes to and from the wetland. Because of the small heat storage of the water body, evaporation rates closely track solar radiation on short time scales. The effect of advected energy related to precipitation is small because the water quickly heats up by solar radiation following precipitation. Advected energy related to ground water is minimal because ground-water fluxes are small and groundwater temperature is only about 7 ??C. Energy flux related to sediment heating and thermal storage in the sediments, which might be expected to be large because the water is clear and shallow, affects evaporation rates by less than 5 percent.

  16. Investigation of correlation of the variations in land subsidence (detected by continuous GPS measurements) and methodological data in the surrounding areas of Lake Urmia

    NASA Astrophysics Data System (ADS)

    Moghtased-Azar, K.; Mirzaei, A.; Nankali, H. R.; Tavakoli, F.

    2012-11-01

    Lake Urmia, a salt lake in the north-west of Iran, plays a valuable role in the environment, wildlife and economy of Iran and the region, but now faces great challenges for survival. The Lake is in immediate and great danger and is rapidly going to become barren desert. As a result, the increasing demands upon groundwater resources due to expanding metropolitan and agricultural areas are a serious challenge in the surrounding regions of Lake Urmia. The continuous GPS measurements around the lake illustrate significant subsidence rate between 2005 and 2009. The objective of this study was to detect and specify the non-linear correlation of land subsidence and temperature activities in the region from 2005 to 2009. For this purpose, the cross wavelet transform (XWT) was carried out between the two types of time series, namely vertical components of GPS measurements and daily temperature time series. The significant common patterns are illustrated in the high period bands from 180-218 days band (~6-7 months) from September 2007 to February 2009. Consequently, the satellite altimetry data confirmed that the maximum rate of linear trend of water variation in the lake from 2005 to 2009, is associated with time interval from September 2007 to February 2009. This event was detected by XWT as a critical interval to be holding the strong correlation between the land subsidence phenomena and surface temperature. Eventually the analysis can be used for modeling and prediction purposes and probably stave off the damage from subsidence phenomena.

  17. Measurements of Land Subsidence Rates on the North-western Portion of the Nile Delta Using Radar Interferometry Techniques

    NASA Astrophysics Data System (ADS)

    Fugate, Joseph M.

    The Nile Delta is home to around 75 million people and most of Egypt's farmland and agricultural production. This area is currently threatened by Mediterranean Sea waters due to factors such as sediment starvation, climate change, and sea level fluctuations as well as subsidence. The low elevation and relief of the Nile Delta exposes many coastal communities, including the city of Alexandria, to potential inundation. This situation has become a concern for the area's residents but a better understanding of the processes occurring there can aid in deciding a suitable response. Recent studies have documented Holocene subsidence rates in the northeast part of the Nile Delta that average up to 8mm/year. In this study, PS-InSAR techniques are used to measure modern land subsidence rates on the north-central and north-western Nile Delta. Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) techniques were applied to 23 ESA radar scenes from 2 orbital tracks spanning from 1992 to 2000 in the north-central and north-west portions of the Nile Delta. The area includes the cities of Alexandria, Greater Mahala, and Mansoura as well as the Rosetta promontory and lake Burullus, Idku Lagoon, and Maryut Lagoon. Results indicate that modern average-vertical ground motion velocities for the north-western and north-central Nile Delta range from emergent to subsidence of 8.5 mm/yr. The range of velocities measured are spatially varied in a complex way across the study area. Patterns of subsidence correlate closely to areas of most recent sediment deposition such as along coastlines and rivers, as well as in lagoons and lakes. Average subsidence velocities are also lower across the western sections of the Nile Delta than in the northeastern delta.

  18. Eastern Denali Fault Slip Rate and Paleoseismic History, Kluane Lake Area, Yukon Territory, Canada

    NASA Astrophysics Data System (ADS)

    Seitz, G. J.; Haeussler, P. J.; Crone, A. J.; Lipovsky, P.; Schwartz, D. P.

    2008-12-01

    In 2002, the central part of the dextral-slip Denali fault (DF) system generated a M 7.9 earthquake in central Alaska. This rupture included the section of the Denali fault with the highest measured late Pleistocene slip rate, of 12.1±1.7 mm/yr, and the Totschunda fault, with a slip rate of 6.0±1.2 mm/yr. Immediately east of the Denali-Totschunda fault juncture, the slip rate on the eastern Denali fault (EDF) decreases to 8.4±2.2 mm/yr. We present observations of Holocene fault activity on the Yukon part of the EDF (Shakwak segment), which is located about 280 km southeast of the Denali-Totschunda intersection in the vicinity of Kluane Lake. Aerial reconnaissance in 2007, from the Denali-Totschunda fault juncture to the Kluane Lake region revealed a nearly continuously identifiable fault trace, which is occasionally obscured where it is subparallel to glacial landforms. In addition to geomorphic features associated with strike-slip faults, such as shutter ridges and sag ponds, the fault is commonly expressed by a chain of elongate mounds, likely tectonic pushups, 20-70 m in length, 10-50 m wide, and locally up to 10 m high. These appear to have formed by shortening between en echelon left-stepping fault strands that developed in layered glacial sediments. At one location (61°18'30.12" N, 139°01'02.54"W) we measured on the ground a channel offset of 20-25 m. An aerial view showed that other channels in the vicinity, as well as the margins of two mounds, were offset by similar amounts. These channels likely developed after deglaciation 10-12 ka. Using this age and the offset yields a slip-rate range of 1.7-2.5 mm/yr, a minimum value but one that may be close to the actual rate. However, because of uncertainties in age relations between construction of the uplift mounds and channel incision the offset could be younger and we estimate an upper limit of about 5 mm/yr. Adjacent to and south of the Duke River, an approximately 2-km-long section of the fault is

  19. Assessment of the fish tumor beneficial use impairment in brown bullhead (Ameiurus nebulosus) at selected Great Lakes Areas of Concern

    USGS Publications Warehouse

    Blazer, Vicki; Mazik, Patricia M.; Iwanowicz, Luke R.; Braham, Ryan P.; Hahn, Cassidy M.; Walsh, Heather L.; Sperry, Adam J.

    2014-01-01

    A total of 878 adult Brown Bullhead were collected at 11 sites within the Lake Erie and Lake Ontario drainages from 2011 to 2013. The sites included seven Areas of Concern (AOC; 670 individuals), one delisted AOC (50 individuals) and three non-AOC sites (158 individuals) used as reference sites. These fish were used to assess the “fish tumor or other deformities” beneficial use impairment. Fish were anesthetized, weighed, measured and any external abnormalities documented and removed. Abnormal orocutaneous and barbel tissue, as well as five to eight pieces of liver, were preserved for histopathological analyses. Otoliths were removed and used for age analyses. Visible external abnormalities included reddened (raised or eroded), melanistic areas and raised growths on lips, body surface, fins and barbels. Microscopically, these raised growths included papilloma, squamous cell carcinoma, osteoma and osteosarcoma. Proliferative lesions of the liver included bile duct hyperplasia, foci of cellular alteration, bile duct (cholangioma, cholangiocarcinoma) and hepatocellular (adenoma, hepatic cell carcinoma) neoplasia. The two reference sites (Long Point Inner Bay, Conneaut Creek), at which 30 or more bullhead were collected had a skin tumor prevalence of 10% or less and liver tumor prevalence of 4% or less. Presque Isle Bay, recently delisted, had a similar liver tumor prevalence (4%) and slightly higher prevalence (12%) of skin tumors. The prevalence of skin neoplasms was 15% or less at sites in the Black River, Cuyahoga River and Maumee AOCs, while more than 20% of the bullheads from the Rochester Embayment, Niagara River, Detroit River and Ashtabula River AOCs had skin tumors. The prevalence of liver tumors was greater than 4% at all AOC sites except the Old Channel site at the Cuyahoga River AOC, Wolf Creek within the Maumee AOC and the upper and lower sites within the Niagara River AOC.

  20. Blastomycosis in Northwestern Ontario

    PubMed Central

    McIntyre, Lynn

    1985-01-01

    Nine cases of blastomycosis were seen at the Sioux Lookout Zone Hospital in northwestern Ontario from 1970 to 1983. Although this region has been described as a focus of endemic infection, little published information is available. Seven male and two female Canadian Indians, aged 4-54 years, acquired the infection. Three children were infected; a mother and her son became ill one month apart. All cases presented as progressive pulmonary disease and no extrapulmonary involvement was found. Delay in diagnosis ranged from 11 days to eight weeks, with a mean of 31 days. Patients generally responded favorably to treatment with amphotericin B. Epidemiologic data suggest that environmental, geographic, occupational and recreational determinants are necessary factors in disease acquisition. PMID:21279155

  1. Combining AHP with GIS for landfill site selection: a case study in the Lake Beyşehir catchment area (Konya, Turkey).

    PubMed

    Sener, Sehnaz; Sener, Erhan; Nas, Bilgehan; Karagüzel, Remzi

    2010-11-01

    Landfills are the most common method for the disposal of municipal solid waste (MSW) in Turkey. However, determining the location of landfill sites is a difficult and complex process because it must combine social, environmental and technical parameters. Additionally, it depends on several criteria and regulations. The main objective of this study was to select of a landfill site for the Lake Beyşehir catchment area. The Beyşehir Lake is the largest freshwater lake and drinking water reservoir in Turkey, but there is no controlled landfill site in the region. Therefore, the landfill site should be determined such that the lake is protected. To determine the most suitable landfill site, an analytical hierarchy process (AHP) was combined with a geographic information system (GIS) to examine several criteria, such as geology/hydrogeology, land use, slope, height, aspect and distance from settlements, surface waters, roads, and protected areas (ecologic, scientific or historic). Each criterion was evaluated with the aid of AHP and mapped by GIS. Data were assorted into four suitability classes within the study area, i.e., high, moderate, low and very low suitability areas, which represented 3.24%, 7.55%, 12.70% and 2.81%, of the study area, respectively. Additionally, 73.70% was determined to be completely unsuitable for a landfill site. As a result, two candidate landfill sites are suggested and discussed. The final decision for landfill site selection will require more detailed field studies. PMID:20594819

  2. Mineral resources of the Albert Rim wilderness study area, Lake County, Oregon

    SciTech Connect

    Sherlock, M.G.; Gettings, M.E. King, H.D.; Neumann, T.R.

    1988-01-01

    This paper reports on the 23,760-acre Abert Rim Wilderness Study Area for mineral resources (known) and mineral resource potential (undiscovered). No mineral resources were identified. A field reconnaissance of the study area revealed no areas of alteration that might be associated with mineralization. Results of geochemical analysis do not suggest mineralization. Rocks associated with gold and mercury mineralization are located in the surrounding region. Geophysical analysis suggests that these rock types may be located at shallow depths under parts of the study area. Therefore, parts of the study area have low potential for gold, mercury, and uranium. The entire study area has moderate potential for geothermal resources and low potential for oil and gas.

  3. Mineral resources of the Holy Cross Wilderness Area, Eagle, Pitkin, and Lake Counties, Colorado

    SciTech Connect

    Wallace, A.R.; Lee, G.K.; Campbell, D.L.; Lundby, W.; Brown, S.D.

    1989-01-01

    The Holy Cross Wilderness Area is in the northern Sawatch Range of central Colorado. This area is underlain principally by Proterozoic metamorphic and igneous rocks, which are unconformably overlain by Paleozoic sedimentary rocks along the flanks of the range. Numerous Late Cretaceous and Tertiary plutons were emplaced into the older rocks, and all rocks are cut by numerous faults. Identified resources in this wilderness area include high-purity limestone and gold-silver ore. Parts of this wilderness area have a high or a moderate resource potential for deposits of base and precious metals and molybdenum, for sand and gravel, and for high-purity limestone.

  4. Geochronology of archean gneisses in the Lake Helen area, Southwestern Big Horn Mountains, Wyoming

    USGS Publications Warehouse

    Arth, Joseph G.; Barker, F.; Stern, T.W.

    1980-01-01

    The RbSr and UPb methods were used to study gneisses in the 7 1 2-minute Lake Helen quadrangle of the Big Horn Mountains, Wyoming. Two episodes of magmatism, deformation and metamorphism occurred during the Archean. Trondhjemitic to tonalitic orthogneisses and amphibolite of the first episode (E-1) are cut by a trondhjemite pluton and a calc-alkaline intrusive series of the second episode (E-2). The E-2 series includes hornblende-biotite quartz diorite, biotite tonalite, biotite granodiorite and biotite granite. A RbSr whole-rock isochron for E-1 gneisses indicates an age of 3007 ?? 34 Ma (1 sigma) and an initial 87Sr/86Sr of 0.7001 ?? 0.0001. UPb determination on zircon from E-1 gneisses yield a concordia intercept age of 2947 ?? 50 Ma. The low initial ratio suggests that the gneisses had no significant crustal history prior to metamorphism, and that the magmas from which they formed had originated from a mafic source. A RbSr whole-rock isochron for E-2 gneisses gives an age of 2801 ?? 31 Ma. The 87Sr/86Sr initial ration is 0.7015 ?? 0.0002 and precludes the existence of the rocks for more than 150 Ma prior to metamorphism. The E-2 magmas may have originated from melting of E-1 gneisses or from a more mafic source. ?? 1980.

  5. Texture, Carbonate Content, and Preliminary Maps of Surficial Sediments of the Flower Garden Banks Area, Northwestern Gulf of Mexico Outer Shelf

    USGS Publications Warehouse

    Scanlon, Kathryn M.; Ackerman, Seth D.; Rozycki, Jill E.

    2003-01-01

    The purpose of this report is to release texture and carbonate content analyses of 107 seafloor sediments collected within and near the East and West Flower Garden Banks areas of the Sanctuary and to show relationships between these data and existing bathymetric data. The sediment data, in conjunction with previously collected geological, geophysical and biological data were used to construct a reconnaissance-scale map of the distribution of seafloor sediment types. This map will be useful for resource managers and can be used, with additional data, as a basis for future habitat mapping.

  6. Aeromagnetic map of the Holy Cross Wilderness Area, Eagle, Lake, and Pitkin counties, Colorado

    USGS Publications Warehouse

    Campbell, D.L.; Wallace, A.R.

    1986-01-01

    Map B is a generalized bedrock geologic map of the wilderness area, showing locations of faults, shear zones, and geologic units referred to in this report. Many smaller outcrops are not shown on Map B, however. For precise locations, descriptions of geologic units, and a more complete discussion of the geology of the wilderness area, see the companion map by Wallace and others (1986).

  7. Distributions of phosphorus fractions in the sediments of a river-lake system: a case study in Huai River catchment area, China.

    PubMed

    Jingqiu, Piao; Changyuan, Tang; Xianfang, Song

    2015-01-01

    Phosphorus (P) forms, with respect to sediment characteristics, and an in-stream sluice were studied in the river-lake system, Huai River catchment area, China. The mean of total P in sediments in the mainstream of the Huai River was higher than that in the Hongze Lake. It was found that P fractions varied in the sediments throughout the river and lake. Detrital-P was the dominant P fraction in the mainstream and organic P and detrital-P were the dominant P fractions in the lake, which could indicate: biologically available and non-biologically available forms. Useful information for the interpretation of P fractions could also be obtained from major sediment characteristics. Whether the relations between P fractions and grain size characteristics were significant or weak, 0.125 mm was a threshold grain size for P fraction distribution in sediment. In addition, the Bengbu Sluice, one of the most important in-stream facilities in the Huai River catchment area, regulated not only the transport of P in sediments upstream and downstream of the sluice, but also the distribution of P fractions in the river-lake system. Therefore, it was confirmed that nutrient loadings could be prevented from reaching the watershed, as well as improved ecological diversity by integrating sluice operation. PMID:26287843

  8. Distance-Decay and Taxa-Area Relationships for Bacteria, Archaea and Methanogenic Archaea in a Tropical Lake Sediment

    PubMed Central

    Barreto, Davi Pedroni; Conrad, Ralf; Klose, Melanie; Claus, Peter; Enrich-Prast, Alex

    2014-01-01

    The study of of the distribution of microorganisms through space (and time) allows evaluation of biogeographic patterns, like the species-area index (z). Due to their high dispersal ability, high reproduction rates and low rates of extinction microorganisms tend to be widely distributed, and they are thought to be virtually cosmopolitan and selected primarily by environmental factors. Recent studies have shown that, despite these characteristics, microorganisms may behave like larger organisms and exhibit geographical distribution. In this study, we searched patterns of spatial diversity distribution of bacteria and archaea in a contiguous environment. We collected 26 samples of a lake sediment, distributed in a nested grid, with distances between samples ranging from 0.01 m to 1000 m. The samples were analyzed using T-RFLP (Terminal restriction fragment length polymorphism) targeting mcrA (coding for a subunit of methyl-coenzyme M reductase) and the genes of Archaeal and Bacterial 16S rRNA. From the qualitative and quantitative results (relative abundance of operational taxonomic units) we calculated the similarity index for each pair to evaluate the taxa-area and distance decay relationship slopes by linear regression. All results were significant, with mcrA genes showing the highest slope, followed by Archaeal and Bacterial 16S rRNA genes. We showed that the microorganisms of a methanogenic community, that is active in a contiguous environment, display spatial distribution and a taxa-area relationship. PMID:25330320

  9. Hydrothermal and tectonic activity in northern Yellowstone Lake, Wyoming

    USGS Publications Warehouse

    Johnson, S.Y.; Stephenson, W.J.; Morgan, L.A.; Shanks, Wayne C.; Pierce, K.L.

    2003-01-01

    Yellowstone National Park is the site of one of the world's largest calderas. The abundance of geothermal and tectonic activity in and around the caldera, including historic uplift and subsidence, makes it necessary to understand active geologic processes and their associated hazards. To that end, we here use an extensive grid of high-resolution seismic reflection profiles (???450 km) to document hydrothermal and tectonic features and deposits in northern Yellowstone Lake. Sublacustrine geothermal features in northern Yellowstone Lake include two of the largest known hydrothermal explosion craters, Mary Bay and Elliott's. Mary Bay explosion breccia is distributed uniformly around the crater, whereas Elliott's crater breccia has an asymmetric distribution and forms a distinctive, ???2-km-long, hummocky lobe on the lake floor. Hydrothermal vents and low-relief domes are abundant on the lake floor; their greatest abundance is in and near explosion craters and along linear fissures. Domed areas on the lake floor that are relatively unbreached (by vents) are considered the most likely sites of future large hydrothermal explosions. Four submerged shoreline terraces along the margins of northern Yellowstone Lake add to the Holocene record or postglacial lake-level fluctuations attributed to "heavy breathing" of the Yellowstone magma reservoir and associated geothermal system. The Lake Hotel fault cuts through northwestern Yellowstone Lake and represents part of a 25-km-long distributed extensional deformation zone. Three postglacial ruptures indicate a slip rate of ???0.27 to 0.34 mm/yr. The largest (3.0 m slip) and most recent event occurred in the past ???2100 yr. Although high heat flow in the crust limits the rupture area of this fault zone, future earthquakes of magnitude ???5.3 to 6.5 are possible. Earthquakes and hydrothermal explosions have probably triggered landslides, common features around the lake margins. Few high-resolution seismic reflection surveys have

  10. Water quality of Lake Austin and Town Lake, Austin, Texas

    SciTech Connect

    Andrews, F.L.; Wells, F.C.; Shelby, W.J.; McPherson, E.M.

    1988-01-01

    Lake Austin and Town Lake are impoundments on the Colorado River in Travis County, central Texas, and are a source of water for municipal industrial water supplies, electrical-power generation, and recreation for more than 500,000 people in the Austin metropolitan area. Small vertical temperature variations in both lakes were attributed to shallow depths in the lakes and short retention times of water in the lakes during the summer months. The largest areal variations in dissolved oxygen generally occur in Lake Austin during the summer as a result of releases of water from below the thermocline in Lake Travis. Except for iron, manganese, and mercury, dissolved concentrations of trace elements in water collected from Lake Austin and Town Lake did not exceed the primary or secondary drinking water standards set by the US Environmental Protection Agency. Little or no effect of stormwater runoff on temperature, dissolved oxygen, or minor elements could be detected in either Lake Austin or Town Lake. Little seasonal or areal variation was noted in nitrogen concentrations in Lake Austin or Town lake. Total phosphorus concentrations generally were small in both lakes. Increased concentrations of nitrogen and phosphorus were detected after storm runoff inflow in Town Lake, but not in Lake Austin; densities of fecal-coliform bacteria increased in Lake Austin and Town Lake, but were substantially greater in Town Lake than in Lake Austin. 18 refs., 38 figs., 59 tabs.

  11. New lakes in deglaciating high-mountain areas: Regional intercomparison of current and future risks from impact waves due to rock/ice avalanches in the Swiss Alps

    NASA Astrophysics Data System (ADS)

    Schaub, Y.; Huggel, C.; Serraino, M.; Haeberli, W.

    2012-04-01

    The changes in high-mountain environments are increasingly fast and complex. GIS-based models of the Swiss Alps show that numerous topographic overdeepenings are likely to appear on progressively exposed glacier beds, which are considered as potential sites of future lake formation. In many cases these newly forming lakes will be situated in an over-steepened and destabilized high-mountain environment and are, therefore, prone to impact waves from landslides. The risk of glacier lake outburst floods, endangering infrastructure, residential areas and persons further downvalley, is increasing with further lake formation and glacier recession. This risk may persist for many decades if not centuries. Future-oriented hazard assessments have to be integrative and must deal with all possible process chains. Reference studies and methodologies are still scarce, however. We present an approach to compare risks resulting from high-mountain lakes in the Swiss Alps amongst each other. Already existing lakes are thereby as much included in the analysis as future ones. The