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.

Lake trout in northern Lake Huron spawn on submerged drumlins

USGS Publications Warehouse

Riley, Stephen C.; Binder, Thomas; Wattrus, Nigel J.; Faust, Matthew D.; Janssen, John; Menzies, John; Marsden, J. Ellen; Ebener, Mark P.; Bronte, Charles R.; He, Ji X.; Tucker, Taaja R.; Hansen, Michael J.; Thompson, Henry T.; Muir, Andrew M.; Krueger, Charles C.

2014-01-01

Recent observations of spawning lake trout Salvelinus namaycush near Drummond Island in northern Lake Huron indicate that lake trout use drumlins, landforms created in subglacial environments by the action of ice sheets, as a primary spawning habitat. From these observations, we generated a hypothesis that may in part explain locations chosen by lake trout for spawning. Most salmonines spawn in streams where they rely on streamflows to sort and clean sediments to create good spawning habitat. Flows sufficient to sort larger sediment sizes are generally lacking in lakes, but some glacial bedforms contain large pockets of sorted sediments that can provide the interstitial spaces necessary for lake trout egg incubation, particularly if these bedforms are situated such that lake currents can penetrate these sediments. We hypothesize that sediment inclusions from glacial scavenging and sediment sorting that occurred during the creation of bedforms such as drumlins, end moraines, and eskers create suitable conditions for lake trout egg incubation, particularly where these bedforms interact with lake currents to remove fine sediments. Further, these bedforms may provide high-quality lake trout spawning habitat at many locations in the Great Lakes and may be especially important along the southern edge of the range of the species. A better understanding of the role of glacially-derived bedforms in the creation of lake trout spawning habitat may help develop powerful predictors of lake trout spawning locations, provide insight into the evolution of unique spawning behaviors by lake trout, and aid in lake trout restoration in the Great Lakes.

ROUND LAKE WILDERNESS STUDY AREA, WISCONSIN.

USGS Publications Warehouse

Cannon, W.F.; Williams, Bradford B.

1984-01-01

The Round Lake Wilderness study area in Wisconsin was studied using geophysical and geochemical surveys, examination of a few bedrock exposures near the area (none are known within the area) and augering and testing of peat deposits. The only direct indication of potential mineral resource is about 760,000 tons of commercial quality peat contained in several bogs. Larger deposits of similar material are abundant closer to markets and although the peat in this area is classified as a demonstrated resource within an area of substantiated peat resource potential, it is considered to be of little importance. The study area lies within a belt of ancient volcanic rocks extending across northern Wisconsin in which several important copper, zinc, and lead deposits were discovered but no indication of such deposits was found within the area.

Lake System Development on the northern Tibetan Plateau during the last 12 ka

NASA Astrophysics Data System (ADS)

Ramisch, A. C.; Lockot, G.; Kasper, T.; Schulte, P.; Zhang, Y.; Daut, G.; Haberzettl, T.; Stauch, G.; Hartmann, K.; Zhu, L.; Lehmkuhl, F.; Maeusbacher, R.; Wuennemann, B.; Diekmann, B.

2013-12-01

Lake systems and their drainage basins provide valuable information of late Quaternary palaeo-environmental conditions on the Tibetan Plateau (TP). This information is often difficult to interpret because of a complex forcing-response mechanism of lake systems and their environment. Here we present an analysis of the endogenic mineral precipitation of Lake Heihai (northern TP) and its environmental constrains expressed by the exogenic mineral input. The mineralogical analysis of carbonate phases by means of X-ray diffraction revealed three distinct stages of carbonate precipitation: Aragonite (late Glacial), Monohydrocalcite (early to mid-Holocene) and Mg bearing Calcite (late Holocene). Each phase precipitates under steady state conditions of exogenic mineral input, as determined by a phase space analysis. This suggests a self-organized precipitation process driven by interactions of different ions. Hence, under steady environmental conditions carbonate precipitation is strongly dependent on the ionic compositions of the lake water and thus controlled by sources of the exogenic mineral input. To analyze the provenance of the exogenic mineral input, a Fuzzy C-Means (FCM) Clustering algorithm was performed on the minerogenic detrital fraction of the total mineral content of 57 surface reference samples. Three major sources can be distinguished: (a) glacially mediated, far distant transport originating from SE catchment (b) precipitation generated, close distant runoff originating from the SW catchment and (c) close distant transport of granite weathering products in the northern parts of the drainage basin. A change from the compositional dominance of (b) over (a) to (a) over (b) in lake sediments suggests a transition from rainfall to glacier dominated runoff production and hence drier climate conditions in the study area during the late Holocene. The environmentally controlled changes in the exogenic mineral input are compared to two different lake systems: Lake

Natural reservoirs and triggered seismicity: a study of two northern Utah Lakes

NASA Astrophysics Data System (ADS)

Whidden, K. M.; Hansen, K.; Timothy, M.; Boltz, M. S.; Pankow, K. L.; Koper, K. D.

2014-12-01

The Great Salt Lake (GSL) and Utah Lake (UL) in northern Utah are in the middle of the Intermountain Seismic Belt, a band of active seismicity extending from western Montana through central Utah to northern Arizona. The proximity of these water bodies to an active earthquake zone is ideal for an investigation of lake-triggered seismicity. Both GSL and UL are shallow (10 and 4.3 m, respectively). The fresh water UL drains via the Jordan River into the salty GSL, which has no outlet. GSL has an aerial extent of 4400 km2, and the shallow depth and lack of outlet cause the surface area to change greatly as the lake volume increases and decreases. UL is much smaller with an almost constant aerial extent of 385 km2. For each lake, we compare yearly earthquake counts near the lake to yearly average lake level for years 1975-2013. GSL seismicity and lake level data correlate well, with seismicity increasing 3-5 years after lake level rise (cross correlation coefficient=0.56, P-value=0.0005). There is an especially large increase in seismicity in 1989 NE of the GSL following the historic lake level high stand in the mid-1980s. The 1989 seismicity has characteristics of both a swarm and a traditional mainshock/aftershock sequence. We will use a double-difference method (HypoDD) to relocate these earthquakes. UL seismicity does not correlate well with the lake level. The different results for the two lakes could perhaps be explained by the lakes' different sizes and the fact that UL has an outlet while GSL does not. The difference might also be explained by subsurface fluid pathways and available faults for nucleating earthquakes. We will further explore the significance of the GSL seismicity and lake level correlation by generating synthetic earthquake catalogs and cross correlating their yearly earthquake counts with the lake level data.

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.

Large increases in carbon burial in northern lakes during the Anthropocene

NASA Astrophysics Data System (ADS)

Heathcote, Adam J.; Anderson, N. John; Prairie, Yves T.; Engstrom, Daniel R.; Del Giorgio, Paul A.

2015-11-01

Northern forests are important ecosystems for carbon (C) cycling and lakes within them process and bury large amounts of organic-C. Current burial estimates are poorly constrained and may discount other shifts in organic-C burial driven by global change. Here we analyse a suite of northern lakes to determine trends in organic-C burial throughout the Anthropocene. We found burial rates increased significantly over the last century and are up to five times greater than previous estimates. Despite a correlation with temperature, warming alone did not explain the increase in burial, suggesting the importance of other drivers including atmospherically deposited reactive nitrogen. Upscaling mean lake burial rates for each time period to global northern forests yields up to 4.5 Pg C accumulated in the last 100 years--20% of the total burial over the Holocene. Our results indicate that lakes will become increasingly important for C burial under future global change scenarios.

Modern thermokarst lake dynamics in the continuous permafrost zone, northern Seward Peninsula, Alaska

USGS Publications Warehouse

Jones, Benjamin M.; Grosse, G.; Arp, C.D.; Jones, M.C.; Walter, Anthony K.M.; Romanovsky, V.E.

2011-01-01

Quantifying changes in thermokarst lake extent is of importance for understanding the permafrost-related carbon budget, including the potential release of carbon via lake expansion or sequestration as peat in drained lake basins. We used high spatial resolution remotely sensed imagery from 1950/51, 1978, and 2006/07 to quantify changes in thermokarst lakes for a 700 km2 area on the northern Seward Peninsula, Alaska. The number of water bodies larger than 0.1 ha increased over the entire observation period (666 to 737 or +10.7%); however, total surface area decreased (5,066 ha to 4,312 ha or -14.9%). This pattern can largely be explained by the formation of remnant ponds following partial drainage of larger water bodies. Thus, analysis of large lakes (>40 ha) shows a decrease of 24% and 26% in number and area, respectively, differing from lake changes reported from other continuous permafrost regions. Thermokarst lake expansion rates did not change substantially between 1950/51 and 1978 (0.35 m/yr) and 1978 and 2006/07 (0.39 m/yr). However, most lakes that drained did expand as a result of surface permafrost degradation before lateral drainage. Drainage rates over the observation period were stable (2.2 to 2.3 per year). Thus, analysis of decadal-scale, high spatial resolution imagery has shown that lake drainage in this region is triggered by lateral breaching and not subterranean infiltration. Future research should be directed toward better understanding thermokarst lake dynamics at high spatial and temporal resolution as these systems have implications for landscape-scale hydrology and carbon budgets in thermokarst lake-rich regions in the circum-Arctic.

Sources of methylmercury to a wetland-dominated lake in northern Wisconsin.

PubMed

Watras, C J; Morrison, K A; Kent, A; Price, N; Regnell, O; Eckley, C; Hintelmann, H; Hubacher, T

2005-07-01

Several lines of evidence suggest that wetlands may be a major source of methylmercury (MeHg) to receiving waters, perhaps explaining the strong correlation between concentrations of waterborne MeHg and dissolved organic carbon (DOC) in regions such as northern Wisconsin. We evaluated the relative importance of wetland export in the MeHg budget of a wetland-dominated lake in northern Wisconsin using mass balance. Channelized runoff from a large headwater wetland was the major source of water and total mercury (HgT) to the lake during the study period. The wetland also exported MeHg in high concentrations (0.2-0.8 ng L(-1)), resulting in an export rate similar to those reported for other northern wetlands (ca. 0.3 microg MeHg m(-2) y(-1)). Yet, based on intensive sampling during 2002, the mass of MeHg that accumulated in the lake during summer was an order of magnitude greater than the export of MeHg from the wetland to the lake. Hence, a large in-lake source of MeHg is inferred from the mass balance. Most of the accumulated MeHg built-up in anoxic hypolimnetic waters; and the build-up was roughly balanced by losses of inorganic Hg (Hg(II)) implying a chemical transformation within the anoxic water column. An abundance of sulfate-reducing bacteria (SRB) in hypolimnetic waters, established by DNA analysis of the pelagic microbial community, along with a previous report documenting high methylation rates in the hypolimnion of this lake (ca. 10% d(-1)), suggest that this transformation was microbially mediated. These findings indicate that the direct effect of wetland runoff may be outweighed by indirect effects on the lacustrine MeHg cycle, enhancing the load of Hg(II), the activity of SRB, and the retention of MeHg, especially in northern lakes with flushing times longer than six months.

A Citizen Science Program for Monitoring Lake Stages in Northern Wisconsin

NASA Astrophysics Data System (ADS)

Kretschmann, A.; Drum, A.; Rubsam, J.; Watras, C. J.; Cellar-Rossler, A.

2011-12-01

Historical data indicate that surface water levels in northern Wisconsin are fluctuating more now than they did in the recent past. In the northern highland lake district of Vilas County, Wisconsin, concern about record low lake levels in 2008 spurred local citizens and lake associations to form a lake level monitoring network comprising citizen scientists. The network is administered by the North Lakeland Discovery Center (NLDC, a local NGO) and is supported by a grant from the Citizen Science Monitoring Program of the Wisconsin Department of Natural Resources (WDNR). With technical guidance from limnologists at neighboring UW-Madison Trout Lake Research Station, citizen scientists have installed geographic benchmarks and staff gauges on 26 area lakes. The project engages citizen and student science participants including homeowners, non-profit organization member-participants, and local schools. Each spring, staff gauges are installed and referenced to fixed benchmarks after ice off by NLDC and dedicated volunteers. Volunteers read and record staff gauges on a weekly basis during the ice-free season; and maintain log books recording lake levels to the nearest 0.5 cm. At the end of the season, before ice on, gauges are removed and log books are collected by the NLDC coordinator. Data is compiled and submitted to a database management system, coordinated within the Wisconsin Surface Water Integrated Monitoring System (SWIMS), a statewide information system managed by the WDNR in Madison. Furthermore, NLDC is collaborating with the SWIMS database manager to develop data entry screens based on records collected by citizen scientists. This program is the first of its kind in Wisconsin to utilize citizen scientists to collect lake level data. The retention rate for volunteers has been 100% over the three years since inception, and the program has expanded from four lakes in 2008 to twenty-six lakes in 2011. NLDC stresses the importance of long-term monitoring and the

Lake Afrera, a structural depression in the Northern Afar Rift (Red Sea).

PubMed

Bonatti, Enrico; Gasperini, Elia; Vigliotti, Luigi; Lupi, Luca; Vaselli, Orlando; Polonia, Alina; Gasperini, Luca

2017-05-01

The boundary between the African and Arabian plates in the Southern Red Sea region is displaced inland in the northern Afar rift, where it is marked by the Red Sea-parallel Erta Ale, Alaita, and Tat Ali volcanic ridges. The Erta Ale is offset by about 20 and 40 km from the two en echelon ridges to the south. The offset area is highly seismic and marked by a depression filled by lake Afrera, a saline body of water fed by hydrothermal springs. Acoustic bathymetric profiles show ≈80 m deep canyons parallel to the NNW shore of the lake, part of a system of extensional normal faults striking parallel to the Red Sea. This system is intersected by oblique structures, some with strike-slip earthquakes, in what might evolve into a transform boundary. Given that the lake's surface lies today about 112 m below sea level, the depressed (minus ≈190 m below sea level) lake's bottom area may be considered the equivalent of the "nodal deep" in slow-slip oceanic transforms. The chemistry of the lake is compatible with the water having originated from hydrothermal liquids that had reacted with evaporites and basalts, rather than residual from evaporation of sea water. Bottom sediments include calcitic grains, halite and gypsum, as well as ostracod and diatom tests. The lake's level appears to have dropped by over 10 m during the last ≈50 years, continuing a drying up trend of the last few thousand years, after a "wet" stage 9,800 and 7,800 years before present when according to Gasse (1973) Lake Afrera covered an area several times larger than at present. This "wet" stage corresponds to an early Holocene warm-humid climate that prevailed in Saharan and Sub Saharan Africa. Lake Abhé, located roughly 250 km south of Afrera, shows similar climate-driven oscillations of its level.

The Petroglyphs at Lake Pend Oreille, Bonner County, Northern Idaho.

DTIC Science & Technology

1985-12-01

LAKE PEND OREILLE BONNER COUNTY, NORTHERN IDAHO 00 00 DTIC rCbELECTE DEC 2 8 1987 US Army Corps 87 12 140 of Engineers 1 Seattle District .t bdaaP O... IDAHO 6. PERFORMING ORG. REPORT NUMBERrNs * 1 7. AUTHOR(e) 8. CONTRACT OR GRANT NUMBER(s) K. Boreson and W.R. Peterson DACW67-85-M-0025 9. PERFORMING...CLASSIFICATION OF THIS PAkGE(Won Data Fntered) % .4 %. %~~ % I lr- rv-tTVK tm V THE PETROGLYPHS AT LAKE PEND OREILLE, BONNER COUNTY, NORTHERN IDAHO By

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.

Using a coupled groundwater/surfacewater model to predict climate-change impacts to lakes in the Trout Lake watershed, Northern Wisconsin

USGS Publications Warehouse

Walker, John F.; Hunt, Randall J.; Markstrom, Steven L.; Hay, Lauren E.; Doherty, John

2009-01-01

A major focus of the U.S. Geological Survey’s Trout Lake Water, Energy, and Biogeochemical Budgets (WEBB) project is the development of a watershed model to allow predictions of hydrologic response to future conditions including land-use and climate change. The coupled groundwater/surface-water model GSFLOW was chosen for this purpose because it could easily incorporate an existing groundwater flow model and it provides for simulation of surface-water processes. The Trout Lake watershed in northern Wisconsin is underlain by a highly conductive outwash sand aquifer. In this area, streamflow is dominated by groundwater contributions; however, surface runoff occurs during intense rainfall periods and spring snowmelt. Surface runoff also occurs locally near stream/lake areas where the unsaturated zone is thin. A diverse data set, collected from 1992 to 2007 for the Trout Lake WEBB project and the co-located and NSF-funded North Temperate Lakes LTER project, includes snowpack, solar radiation, potential evapotranspiration, lake levels, groundwater levels, and streamflow. The timeseries processing software TSPROC (Doherty 2003) was used to distill the large time series data set to a smaller set of observations and summary statistics that captured the salient hydrologic information. The timeseries processing reduced hundreds of thousands of observations to less than 5,000. Model calibration included specific predictions for several lakes in the study area using the PEST parameter estimation suite of software (Doherty 2007). The calibrated model was used to simulate the hydrologic response in the study lakes to a variety of climate change scenarios culled from the IPCC Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Solomon et al. 2007). Results from the simulations indicate climate change could result in substantial changes to the lake levels and components of the hydrologic budget of a seepage lake in the flow system. For a drainage lake

Flood-inundation maps for Lake Champlain in Vermont and in northern Clinton County, New York

USGS Publications Warehouse

Flynn, Robert H.; Hayes, Laura

2016-06-30

extents against the inundation area extents determined for the May 2011 flood (which incorporated documented high-water marksfrom the flood of May 201) (Bjerklie and others, 2014).A digital elevation model (DEM) was created by USGS, within a geographic information system (GIS), from the recently flown and processed light detection and ranging(lidar) data (2013–2014) in Vermont and the lake shore area of northern Clinton County in New York. The lidar data have a vertical accuracy of 0.3 to 0.6-ft (9.6 to 18.0-centimeters [cm]) and a horizontal resolution of 2.3 to 4.6 ft (0.7 to 1.4 meters). This DEM was used in determining the floodboundary for 11 flood stages at 0.5-ft intervals from 100.0 to104.0 ft (NGVD 29) and 1-ft intervals from 104.0 to 106.0 ft (NGVD 29) as referenced to the USGS lake gage 04295000, Richelieu River (Lake Champlain) at Rouses Point, N.Y. In addition, the May 2011 flood-inundation area for elevation103.20 ft (NGVD 29) (102.77 ft, North American Vertical Datum [NAVD] 88) was determined from this DEM. The May 2011 flood is the highest recorded lake water level (stage)at the Rouses Point, N.Y., lake gage. Flood stages greater than 101.5 ft (NGVD 29) exceed the “major flood stage”as defined by the NationalWeather Service for USGS lake gage 04295000.The availability of these maps, along with Internet information regarding current stage from the USGS lake gage and forecasted high-flow stages from the NationalWeather Service, will provide emergency management personnel and residents with information that is critical for flood responseactivities such as evacuations and road closures, as well as for post-flood recovery eforts.

Remotely Sensing Lake Water Volumes on the Inner Arctic Coastal Plain of Northern Alaska

NASA Astrophysics Data System (ADS)

Simpson, C. E.; Arp, C. D.; Jones, B. M.; Hinkel, K. M.; Carroll, M.; Smith, L. C.

2017-12-01

Thermokarst lake depth is controlled by the amount of excess ice in near-surface permafrost, with lake depths of about 1 - 3 m in areas of epigenetic permafrost and over 10 m in areas of syngenetic permafrost. An important exception to these general patterns is found on the inner Arctic Coastal Plain (ACP) of northern Alaska, where deep lakes occur in Pleistocene-aged, ground-ice poor sandy terrain. These lakes cover 20% of the currently inactive sand sheet and dune deposit (referred to as the Pleistocene Sand Sea) that comprises approximately 7000 km2 of the ACP. Surrounded by high and eroding bluffs, sand sea lakes lie in natural depressions and are characterized by wide, shallow littoral shelves and central troughs that are typically oriented NNW to SSE and can reach depths greater than 20 m. Despite their unique form and extensive coverage, these lakes have received little prior study and a literature gap remains regarding regional water storage. This research classifies sand sea lakes, estimates individual lake volume, and provides a first quantification of water storage in a region of the lake-dominated ACP. We measured bathymetric profiles in 19 sand sea lakes using a sonar recorder to capture various lake depth gradients. Bathymetric surveys collected by oil industry consultants, lake monitoring programs, and habitat studies serve as additional datasets. These field measured lake depth data points were used to classify Color Infrared Photography, WorldView-2 satellite imagery, and Landsat-OLI satellite imagery to develop a spectral depth-classification algorithm and facilitate the interpolation of the bathymetry for study lakes in the inner ACP. Finally, we integrate the remotely sensed bathymetry and imagery-derived lake surface area to estimate individual and regional-scale lake volume. In addition to the natural function of these lakes in water storage, energy balance, and habitat provision, the need for winter water supply to build ice roads for oil

Sanctuaries for lake trout in the Great Lakes

USGS Publications Warehouse

Stanley, Jon G.; Eshenroder, Randy L.; Hartman, Wilbur L.

1987-01-01

Populations of lake trout, severely depleted in Lake Superior and virtually extirpated from the other Great Lakes because of sea lamprey predation and intense fishing, are now maintained by annual plantings of hatchery-reared fish in Lakes Michigan, Huron, and Ontario and parts of Lake Superior. The extensive coastal areas of the Great Lakes and proximity to large populations resulted in fishing pressure on planted lake trout heavy enough to push annual mortality associated with sport and commercial fisheries well above the critical level needed to reestablish self-sustaining stocks. The interagency, international program for rehabilitating lake trout includes controlling sea lamprey abundance, stocking hatchery-reared lake trout, managing the catch, and establishing sanctuaries where harvest is prohibited. Three lake trout sanctuaries have been established in Lake Michigan: the Fox Island Sanctuary of 121, 500 ha, in the Chippewa-Ottawa Treaty fishing zone in the northern region of the lake; the Milwaukee Reef Sanctuary of 160, 000 ha in midlake, in boundary waters of Michigan and Wisconsin; and Julian's Reef Sanctuary of 6, 500 ha, in Illinois waters. In northern Lake Huron, Drummond Island Sanctuary of 55, 000 ha is two thirds in Indian treaty-ceded waters in Michigan and one third in Ontario waters of Canada. A second sanctuary, Six Fathom Bank-Yankee Reef Sanctuary, in central Lake Huron contains 168, 000 ha. Sanctuary status for the Canadian areas remains to be approved by the Provincial government. In Lake Superior, sanctuaries protect the spawning grounds of Gull Island Shoal (70, 000 ha) and Devils Island Shoal (44, 000 ha) in Wisconsin's Apostle Island area. These seven sanctuaries, established by the several States and agreed upon by the States, Indian tribes, the U.S. Department of the Interior, and the Province of Ontario, contribute toward solving an interjurisdictional fishery problem.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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 saltmore » 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.« less

RAINBOW LAKE WILDERNESS AND FLYNN LAKE WILDERNESS STUDY AREA, WISCONSIN.

USGS Publications Warehouse

Cannon, W.F.; Dunn, Maynard L.

1984-01-01

The Rainbow Lake Wilderness and Flynn Lake Wilderness study area in Wisconsin are contiguous and were studied as a unit. The rainbow Lake Wilderness contains a demonstrated resource of about 210,000 tons of commercial-quality peat in an area of substantiated peat resource potential. The Flynn Lake Wilderness study area contains a demonstrated resource of about 300,000 tons of commercial-quality peat in an area of substantiated peat resource potential. These deposits, however, are of limited importance because larger deposits of similar material are abundant outside the areas, closer to present markets. Rocks in the subsurface contain a low-grade copper resource identified by mining company exploration drilling. Although this is an area of substantiated copper resource potential, it is a low-grade resource, thin and generally at great depth.

Groundwater flow in a closed basin with a saline shallow lake in a volcanic area: Laguna Tuyajto, northern Chilean Altiplano of the Andes.

PubMed

Herrera, Christian; Custodio, Emilio; Chong, Guillermo; Lambán, Luis Javier; Riquelme, Rodrigo; Wilke, Hans; Jódar, Jorge; Urrutia, Javier; Urqueta, Harry; Sarmiento, Alvaro; Gamboa, Carolina; Lictevout, Elisabeth

2016-01-15

Laguna Tuyajto is a small, shallow saline water lake in the Andean Altiplano of northern Chile. In the eastern side it is fed by springs that discharge groundwater of the nearby volcanic aquifers. The area is arid: rainfall does not exceed 200mm/year in the rainiest parts. The stable isotopic content of spring water shows that the recharge is originated mainly from winter rain, snow melt, and to a lesser extent from some short and intense sporadic rainfall events. Most of the spring water outflowing in the northern side of Laguna Tuyajto is recharged in the Tuyajto volcano. Most of the spring water in the eastern side and groundwater are recharged at higher elevations, in the rims of the nearby endorheic basins of Pampa Colorada and Pampa Las Tecas to the East. The presence of tritium in some deep wells in Pampa Colorada and Pampa Las Tecas indicates recent recharge. Gas emission in recent volcanoes increase the sulfate content of atmospheric deposition and this is reflected in local groundwater. The chemical composition and concentration of spring waters are the result of meteoric water evapo-concentration, water-rock interaction, and mainly the dissolution of old and buried evaporitic deposits. Groundwater flow is mostly shallow due to a low permeability ignimbrite layer of regional extent, which also hinders brine spreading below and around the lake. High deep temperatures near the recent Tuyajto volcano explain the high dissolved silica contents and the δ(18)O shift to heavier values found in some of the spring waters. Laguna Tuyajto is a terminal lake where salts cumulate, mostly halite, but some brine transfer to the Salar de Aguas Calientes-3 cannot be excluded. The hydrogeological behavior of Laguna Tuyajto constitutes a model to understand the functioning of many other similar basins in other areas in the Andean Altiplano. Copyright © 2015 Elsevier B.V. All rights reserved.

Population structure and dynamics of northern pike and smallmouth bass in Coeur d’Alene Lake, Idaho.

USGS Publications Warehouse

Walrath, John D.; Quist, Michael C.; Firehammer, Jon A.

2015-01-01

Numerous species have been introduced to Coeur d'Alene Lake, Idaho over the last century, but minimal research has been completed to understand their population dynamics. The objective of this study was to describe the population demographics and dynamics of northern pike (Esox lucius) and smallmouth bass (Micropterus dolomieu), two important nonnative sport fishes in the system to provide information that will assist with guiding management decisions. The oldest northern pike was age 7 and the oldest smallmouth bass was age 11. Populations of both species exhibited very stable recruitment with a recruitment coefficient of determination of 0.99 for northern pike and 0.98 for smallmouth bass. Total annual mortality was estimated as 66% for northern pike and 42% for smallmouth bass. Growth of northern pike in Coeur d'Alene Lake was comparable to the 50–75th percentiles of growth exhibited by lentic northern pike populations across North America. Northern pike in Coeur d'Alene Lake were most similar to populations in the north-central and northeast United States with fast growth rates and short life spans. In contrast, smallmouth bass grew slowly and generally fell within the 5th percentile of lentic smallmouth bass populations in North America. Smallmouth bass in Coeur d'Alene Lake were similar to other populations in northern regions of the United States displaying slow growth rates with high longevity. Results of this study provide important insight on nonnative northern pike and smallmouth bass population dynamics.

Geophysical investigations of the Olonium Roman site (Northern Como Lake)

NASA Astrophysics Data System (ADS)

Arlsan, Ermanno; Biella, Giancarlo; Boniolo, Graziano; Caporusso, Donatella; de Franco, Roberto; Lozej, Alfredo; Veronese, Luigi

1999-03-01

The study area is located at S. Agata (Gera Lario), a small center at the northern end of Como Lake, near the junction of Valchiavenna and Valtellina Valleys. This site played a strategic role since ancient times, providing the control on the communications routes to both the Como Lake and the Spluga and Septimer alpine passes. Since the end of the last century archaeological findings are reported in literature, also supported, from the early XI century, by archival documents confirming the existence of the `Olonium' settlement, an administrative and fiscal center of primary importance, as well as a parish amongst the most influential in the Como Lake area. Within an area of 45,000 m 2 an electrical survey has been carried out in conjunction with magnetic and GPR investigations. These studies have indicated the presence of a number of sub-areas characterized by significant anomalies defined by the overlapping of the results obtained from two or more geophysical methods. In two of such sub-areas, excavation tests have been conducted, which have brought to light a number of archaeological findings of interest. In one of the two sub-areas, which is characterized by the superimposition of electrical and radar anomalies, a deposit of large pebbles has been found. The origin of this deposit has not been ascertained, whether it is of fluvial origin, related to the deviation of the Adda river in the Pian di Spagna region in Roman times, or it is part of reclamation works, still of Roman times, of paleolacustrine marshes. The overlapping stratigraphy, however, suggests the development of fluvial channels between Roman and Low-Medieval times. In the other sub-area, excavations were carried out on sites defined by electrical and radar anomalies, and confirmed by the results from magnetic survey. The excavations brought to light, below the fluvial deposits, a large medieval edifice, which could be identified as the S. Stefano church abandoned in 1444. The church is built on

Trace element distribution in waters of the northern catchment area of Lake Linneret, northern Israel

NASA Astrophysics Data System (ADS)

Sandler, A.; Brenner, I. B.; Halicz, L.

1988-02-01

Waters of the northern watershed of Lake Kineret, sampled during the period 1978 1983, were analyzed for their major and trace element contents. The trace element concentrations of the major water sources of the watershed (the Dan and Banias springs) represent background values. After emergence, the waters are subjected to human activity. In crossing the populated and cultivated Hula Basin in man-made canals, the major and trace element contents increase. In comparison to the trace element concentrations, those of the major elements have narrow ranges and small temporal fluctuations. Trace element concentrations varied by 3 orders of magnitude, and temporal variations were large but not neccessarily seasonal. Point sources of trace elements were urban effluents, fish pond wastes, and peat soil drainage. The trace element concentrations decrease in the waters of the last segment of the Jordan River. All measured trace elements were below the criteria levels established by regulatory agencies. Several, however, were of the same order of magnitude. Addition of wastes from enhanced recycling, and morphologic modification of the final course of the Jordan River could result in increase in the trace element concentrations in the water.

Strategies for steam handling and H2S abatement at geothermal power plants in the geysers area of Northern California

NASA Astrophysics Data System (ADS)

Morris, W. F.; Stephens, F. B.

1981-08-01

Strict limitations on the emission of H2S from new geothermal power plants in The Geysers area of northern California were imposed by Lake and Northern Sonoma County Air Pollution Control Districts. Lake County, under new source review rules, stipulated that specific technologies should be utilized to limit H2S emissions to 5 lb/h as a condition for determination of compliance. The status of these technologies as well as other ongoing technology development efforts to conserve steam and abate H2S are evaluated.

Analysis of ERS 1 synthetic aperture radar data of frozen lakes in northern Montana and implications for climate studies

USGS Publications Warehouse

Hall, Dorothy K.; Fagre, Daniel B.; Klasner, Fritz; Linebaugh, Gregg; Liston, Glen E.

1994-01-01

Lakes that freeze each winter are good indicators of regional climate change if key parameters, such as freeze-up and breakup date and maximum ice thickness, are measured over a decade-scale time frame. Synthetic aperture radar (SAR) satellite data have proven to be especially useful for measurement of climatologically significant parameters characteristic of frozen lakes. In this paper, five lakes in Glacier National Park, Montana, have been studied both in the field and using Earth Remote-Sensing Satellite (ERS) 1 SAR data during the 1992-1993 winter. The lakes are characterized by clear ice, sometimes with tubular or rounded bubbles, and often with a layer of snow ice on top of the clear ice. They are also often snow covered. Freeze-up is detected quite easily using ERS 1 SAR data as soon as a thin layer of ice forms. The effect of snow ice on the backscatter is thought to be significant but is, as yet, undetermined. On the five lakes studied, relative backscatter was found to increase with ice thickness until a maximum was reached in February. Breakup, an often ill-defined occurrence, is difficult to detect because surface water causes the SAR signal to be absorbed, thus masking the ice below. Comparison of the bubble structure of thaw lakes in northern Alaska with lakes in northern Montana has shown that the ice structure is quite different, and this difference may contribute to differential SAR signature evolution in the lakes of the two areas.

Effects of recruitment, growth, and exploitation on walleye population size structure in northern Wisconsin lakes

USGS Publications Warehouse

Hansen, Michael J.; Nate, Nancy A.

2014-01-01

We evaluated the dynamics of walleye Sander vitreus population size structure, as indexed by the proportional size distribution (PSD) of quality-length fish, in Escanaba Lake during 1967–2003 and in 204 other lakes in northern Wisconsin during 1990–2011. We estimated PSD from angler-caught walleyes in Escanaba Lake and from spring electrofishing in 204 other lakes, and then related PSD to annual estimates of recruitment to age-3, length at age 3, and annual angling exploitation rate. In Escanaba Lake during 1967–2003, annual estimates of PSD were highly dynamic, growth (positively) explained 35% of PSD variation, recruitment explained only 3% of PSD variation, and exploitation explained only 7% of PSD variation. In 204 other northern Wisconsin lakes during 1990–2011, PSD varied widely among lakes, recruitment (negatively) explained 29% of PSD variation, growth (positively) explained 21% of PSD variation, and exploitation explained only 4% of PSD variation. We conclude that population size structure was most strongly driven by recruitment and growth, rather than exploitation, in northern Wisconsin walleye populations. Studies of other species over wide spatial and temporal ranges of recruitment, growth, and mortality are needed to determine which dynamic rate most strongly influences population size structure of other species. Our findings indicate a need to be cautious about assuming exploitation is a strong driver of walleye population size structure.

SKY LAKES ROADLESS AREA AND MOUNTAIN LAKES WILDERNESS, OREGON.

USGS Publications Warehouse

Smith, James G.; Benham, John R.

1984-01-01

Based on a mineral survey of the Sky Lakes Roadless Area and the Mountain Lakes Wilderness, Oregon, the areas have little or no promise for the occurrence of metallic-mineral resources or geothermal energy resources. Nonmetallic resources exist in the areas, but other areas outside the roadless area and wilderness also contain resources of volcanic cinders, scoria, ash, breccia, and sand and gravel which are easier to obtain and closer to markets. The roadless area and wilderness are not geologically favorable for metallic deposits, or for coal, oil, or gas resources.

METHYLMERCURY BIOACCUMULATION DEPENDENCE ON NORTHERN PIKE AGE AND SIZE IN TWENTY MINNESOTA LAKES

EPA Science Inventory

Mercury accumulation in northern pike muscle tissue (fillets) was found to be directly related to fish age and size. Measurements were made on 173 individual northern pike specimens from twenty lakes across Minnesota. Best fit regressions of mercury fillet concentration (wet wt.)...

Littoral zone fish assemblages of northern Cayuga Lake.

USGS Publications Warehouse

McKenna, James E.

2001-01-01

Fish assemblages from northern Cayuga Lake were examined for patterns in temporal structure. Fish assemblages changed significantly between seasons. Bluegill (Lepomis macrochirus), bluntnose minnow (Pimephales notatus), and smallmouth bass (Micropterus dolomieu) formed the basis for most assemblages, but the spring assemblage was dominated by common carp (Cyprinus carpio). Correlations between community structure and abiotic factors were identified. Ten abiotic factors strongly influenced species assemblages, including phosphorus concentration, but could not fully explain differences between assemblages. Results indicate that the seasonal pattern of fish assemblage structure and abundance of fish that tend to feed in the water column were related to the annual cycle of productivity in the lake and behavioral adaptations of the fish.

Sediment Coring of the Proglacial Lake Donguz-Orun (northern Caucasus, Russia)

NASA Astrophysics Data System (ADS)

Alexandrin, Mikhail; Solomina, Olga; Kalugin, Ivan; Darin, Andrey; Nesje, Atle

2014-05-01

So far, no high-resolution reconstructions of climate and glacier variations based on lake sediment properties are available in Caucasus Mountains. In other presently glaciated regions this approach is proved to be very useful for this purpose (e.g. Nesje et al., 2001, 2011; Bakke, 2005, Nesje, 2009) In this paper we report the first results of the sediment coring of Donguz-Orun Lake (N 43°13'26", E 42°29'35") situated in the upper reaches of Donguz-Orun-Kyol, a tributary of Baksan river in the Elbrus region of Northern Caucasus, a typical proglacial lake dammed by a lateral moraine deposited by the Donguz-Orun Glacier. It is a drainage lake with several inflowing glacial streams and effluent river Donguz-Orun. The surface area is around 105 000 m2 with a water volume of 465 000m3. The average water depth is around 4.5 m, with a maximum water depth of 14 m. The deepest part is found close to the moraine dam in the narrow northern part of the lake. This is normally consistent with this type of glacial lake systems. An intensive gravitational drift of the moraine material towards the lake is observed. These non-rounded moraine boulders constitute a significant part of the lakebed. Lacustrine sediments are present though. The coring campaign from Institute of Geography, Russian Academy of Sciences (August 2012) used a modified piston corer with a 110 mm-diameter plastic tube (Nesje, 1992) mounted on the inflatable catamaran to obtain lake sediments from Lake Donguz-Orun. A 28-cm long core was retrieved from a water depth of around 7 m. The sediments consist of regularly laminated, fine beige clay, with several interlayers of sand. The coring process appeared to be challenging due to the stiffness of clay, which led to extreme bending of the sediment layers in the basal part of the core. The original thickness of the sediments was obviously higher than observed in the core. In order to clarify the recent history of the Donguz-Orun glacier, we used lichenometry and

Nutrient dynamics in shallow lakes of Northern Greece.

PubMed

Petaloti, Christina; Voutsa, Dimitra; Samara, Constantini; Sofoniou, Mihalis; Stratis, Ioannis; Kouimtzis, Themistocles

2004-01-01

GOAL, SCOPE, BACKGROUND: Shallow lakes display a number of features that set them apart from the more frequently studied deeper systems. The majority of lakes in Northern Greece are small to moderate in size with a relatively low depth and are considered as sites of high value of the wetland habitat. However, the water quality of these lakes has only been evaluated segmentally and occasionally. The objectives of this study were to thoroughly investigate nitrogen and phosphorus speciation in lakes of a high ecological significance located in N. Greece, in order to evaluate their eutrophication status and possible nutrient limitation factors, and to investigate the main factors/sources that affect the water quality of these systems. An extensive survey was carried out during the period from 1998-1999. Water samples were collected on a monthly basis from lakes Koronia, Volvi, Doirani, Mikri Prespa and Megali Prespa located in N. Greece. Water quality parameters (temperature, dissolved oxygen, pH and conductivity), organic indices (COD, BOD5), and N- and P-species (NO3(-), NO2(-), NH4(+), and PO4(3-), Kieldahl nitrogen and acid-hydrolysable phosphorus) were determined according to standard methods for surface water. Statistical treatment of the data was employed. The physicochemical parameters determined in the lakes studied revealed a high temporal variation. The trophic state of the lakes ranged from meso- to hypertrophic. The nutrient limiting factor varied among lakes suggesting either P-limitation conditions or mixed conditions changing from P- to N-limitation throughout the year. Urban/industrial activities and agricultural runoff are the major factors affecting all lakes, although with a varying contribution. This lake-specific research offers valuable information about water quality and nutrient dynamics in lakes of significant ecological value located in N. Greece that can be useful for an effective pollution control/management of these systems. Due to the

Global change-driven effects on dissolved organic matter composition: Implications for food webs of northern lakes.

PubMed

Creed, Irena F; Bergström, Ann-Kristin; Trick, Charles G; Grimm, Nancy B; Hessen, Dag O; Karlsson, Jan; Kidd, Karen A; Kritzberg, Emma; McKnight, Diane M; Freeman, Erika C; Senar, Oscar E; Andersson, Agneta; Ask, Jenny; Berggren, Martin; Cherif, Mehdi; Giesler, Reiner; Hotchkiss, Erin R; Kortelainen, Pirkko; Palta, Monica M; Vrede, Tobias; Weyhenmeyer, Gesa A

2018-03-15

Northern ecosystems are experiencing some of the most dramatic impacts of global change on Earth. Rising temperatures, hydrological intensification, changes in atmospheric acid deposition and associated acidification recovery, and changes in vegetative cover are resulting in fundamental changes in terrestrial-aquatic biogeochemical linkages. The effects of global change are readily observed in alterations in the supply of dissolved organic matter (DOM)-the messenger between terrestrial and lake ecosystems-with potentially profound effects on the structure and function of lakes. Northern terrestrial ecosystems contain substantial stores of organic matter and filter or funnel DOM, affecting the timing and magnitude of DOM delivery to surface waters. This terrestrial DOM is processed in streams, rivers, and lakes, ultimately shifting its composition, stoichiometry, and bioavailability. Here, we explore the potential consequences of these global change-driven effects for lake food webs at northern latitudes. Notably, we provide evidence that increased allochthonous DOM supply to lakes is overwhelming increased autochthonous DOM supply that potentially results from earlier ice-out and a longer growing season. Furthermore, we assess the potential implications of this shift for the nutritional quality of autotrophs in terms of their stoichiometry, fatty acid composition, toxin production, and methylmercury concentration, and therefore, contaminant transfer through the food web. We conclude that global change in northern regions leads not only to reduced primary productivity but also to nutritionally poorer lake food webs, with discernible consequences for the trophic web to fish and humans. © 2018 John Wiley & Sons Ltd.

Carbonate microbialites and hardgrounds from Manito Lake, an alkaline, hypersaline lake in the northern Great Plains of Canada

NASA Astrophysics Data System (ADS)

Last, Fawn M.; Last, William M.; Halden, Norman M.

2010-03-01

Manito Lake is a large, perennial, Na-SO 4 dominated saline to hypersaline lake located in the northern Great Plains of western Canada. Significant water level decrease over the past several decades has led to reduction in volume and surface area, as well as an increase in salinity. The salinity has increased from 10 ppt to about 50 ppt TDS. This decrease in water level has exposed large areas of nearshore microbialites. These organogenic structures range in size from several cm to over a meter and often form large bioherms several meters high. They have various external morphologies, vary in mineralogical composition, and show a variety of internal fabrics from finely laminated to massive. In addition to microbiolities and bioherms, the littoral zone of Manito Lake contains a variety of carbonate hardgrounds, pavements, and cemented clastic sediments. Dolomite and aragonite are the most common minerals found in these shoreline structures, however, calcite after ikaite, monohydrocalcite, magnesian calcite, and hydromagnesite are also present. The dolomite is nonstoichiometric and calcium-rich; the magnesian calcite has about 17 mol% MgCO 3. AMS radiocarbon dating of paired organic matter and endogenic carbonate material confirms little or no reservoir affect. Although there is abundant evidence for modern carbonate mineral precipitation and microbialite formation, most of the larger microbialites formed between about 2300 and 1000 cal BP, whereas the hardgrounds, cements, and laminated crusts formed about 1000-500 cal BP.

Lake trout rehabilitation in Lake Huron

USGS Publications Warehouse

Eshenroder, Randy L.; Payne, N. Robert; Johnson, James E.; Bowen, Charles; Ebener, Mark P.

1995-01-01

Efforts to restore lake trout (Salvelinus namaycush) in Lake Huron after their collapse in the 1940s were underway in the early 1970s with completion of the first round of lampricide applications in tributary streams and the stocking of several genotypes. We assess results of rehabilitation and establish a historical basis for comparison by quantifying the catch of spawning lake trout from Michigan waters in 1929-1932. Sixty-eight percent of this catch occurred in northern waters (MH-1) and most of the rest (15%) was from remote reefs in the middle of the main basin. Sea lampreys (Petromyzon marinus) increased in the early 1980s in the main basin and depressed spawning populations of lake trout. This increase was especially severe in northern waters and appeared to be associated with untreated populations in the St. Marys River. Excessive commercial fishing stemming from unresolved treaty rights also contributed to loss of spawning fish in northern Michigan waters. Seneca-strain lake trout did not appear to be attacked by sea lampreys until they reached a size > 532 mm. At sizes > 632 mm, Seneca trout were 40-fold more abundant than the Marquette strain in matched-planting experiments. Natural reproduction past the fry stage has occurred in Thunder Bay and South Bay, but prospects for self-sustaining populations of lake trout in the main basin are poor because sea lampreys are too abundant, only one side of the basin is stocked, and stocking is deferred to allow commercial gillnetting in areas where most of the spawning occurred historically. Backcross lake trout, a lake trout x splake (s. Fontinalis x s. Namaycush) hybrid, did not reproduce in Georgian Bay, but this genotype is being replaced with pure-strain lake trout, whose early performance appears promising.

The northern lakes of Egypt: Encounters with a wetland environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parmenter, B.M.

1991-01-01

Five lakes fringe the northern coast of Egypt. Together they represent 25% of the remaining wetland habitat in the Mediterranean basin. Residents of these lakes traditionally exploited a wide variety of resources. Today these lakes face a number of threats to their existence, including large-scale reclamation and water pollution. Agricultural authorities, engineers, fishery managers, and conservationists in Egypt and abroad debate about how best to manage and develop the lake region's resources, but few of these groups understand or communicate with one another, or with residents of lake communities. This study explores how these various groups encounter the coastal lakesmore » of Egypt, focusing particularly on Lakes Manzala and Burullus. Its purpose is to explore the ways in which the lakes, their resources and their inhabitants have been evaluated, and to analyze how underlying preconceptions, goals and structures of professional discourse influence such evaluations. The thesis is that environmental management is in reality not a rational plan but a process. Egypt is currently attempting to develop a coherent strategy to remedy its environmental problems without adversely affecting economic growth.« less

Geologic map of Medicine Lake volcano, northern California

USGS Publications Warehouse

Donnelly-Nolan, Julie M.

2011-01-01

Medicine Lake volcano forms a broad, seemingly nondescript highland, as viewed from any angle on the ground. Seen from an airplane, however, treeless lava flows are scattered across the surface of this potentially active volcanic edifice. Lavas of Medicine Lake volcano, which range in composition from basalt through rhyolite, cover more than 2,000 km2 east of the main axis of the Cascade Range in northern California. Across the Cascade Range axis to the west-southwest is Mount Shasta, its towering volcanic neighbor, whose stratocone shape contrasts with the broad shield shape of Medicine Lake volcano. Hidden in the center of Medicine Lake volcano is a 7 km by 12 km summit caldera in which nestles its namesake, Medicine Lake. The flanks of Medicine Lake volcano, which are dotted with cinder cones, slope gently upward to the caldera rim, which reaches an elevation of nearly 8,000 ft (2,440 m). The maximum extent of lavas from this half-million-year-old volcano is about 80 km north-south by 45 km east-west. In postglacial time, 17 eruptions have added approximately 7.5 km3 to its total estimated volume of 600 km3, and it is considered to be the largest by volume among volcanoes of the Cascades arc. The volcano has erupted nine times in the past 5,200 years, a rate more frequent than has been documented at all other Cascades arc volcanoes except Mount St. Helens.

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)

Lake Powell

NASA Image and Video Library

2007-09-20

The white ring around Lake Powell tells the story. The surface is down 98 feet. This is critical, because Powell, Lake Mead, and other lakes along the Colorado River provide water for millions of people in five states. We are in the eighth year of a drought on the Colorado River. This year was the driest year ever reported in Southern California, and there is a severe drought in Northern California, down to less than 30-percent of snow pack. This ASTER image of part of Lake Powell was acquired in 2001. The gray area depicts the shrunken, reduced 2007 lake extent compared to the extended, larger black area in 2001. The image covers an area of 24 x 30 km, and is centered near 37.1 degrees north latitude, 111.3 degrees west longitude. This image from NASA Terra satellite. http://photojournal.jpl.nasa.gov/catalog/PIA10614

Factors related to northern goshawk landscape use in the western Great Lakes region

USGS Publications Warehouse

Bruggeman, Jason E.; Andersen, David E.; Woodford, James E.

2014-01-01

Northern Goshawks (Accipiter gentilis) are a species of special conservation concern in the western Great Lakes bioregion and elsewhere in North America, and exhibit landscape-scale spatial use patterns. However, little information exists about Northern Goshawk habitat relations at broad spatial extents, as most existing published information comes from a few locations of relatively small spatial extent and, in some cases, short durations. We used an information-theoretic approach to evaluate competing hypotheses regarding factors (forest canopy cover, successional stage, and heights of the canopy top and base) related to odds of Northern Goshawk landscape use throughout the western Great Lakes bioregion based on an occupancy survey completed in 2008 (Bruggeman et al. 2011). We also combined these data with historical data of Northern Goshawk nest locations in the bioregion from 1979–2006 to evaluate the same competing hypotheses to elucidate long-term trends in use. The odds of Northern Goshawk use in 2008, and from 1979–2008, were positively correlated with average percent canopy cover. In the best-approximating models developed using 1979–2008 data, the odds of landscape use were positively correlated with the percentages of the landscape having canopy heights between 10 m and 25 m, and 25 m and 50 m, and the amount of variability in canopy base height. Also, the odds of landscape use were negatively correlated with the average height at the canopy base. Our results suggest multiple habitat factors were related to Northern Goshawk landscape-scale habitat use, similar to habitat use described at smaller spatial scales in the western Great Lakes bioregion and in western North America and Europe.

Reconnaissance data on lakes in the Alpine Lakes Wilderness Area, Washington

USGS Publications Warehouse

Dethier, David P.; Heller, Paul L.; Safioles, Sally A.

1979-01-01

Sixty lakes in the Alpine Lakes Wilderness Area have been sampled from rubber rafts or helicopter to obtain information on their physical setting and on present water-quality conditions. The lakes are located near the crest of the Cascade Range in Chelan and King Counties, Washington. Basic data from these lakes will be useful for planners concerned with lake and wilderness management, and of interest to hikers and other recreationists who use the lakes.

75 FR 35652 - Safety Zone; Northern California Annual Fireworks Events, Fourth of July Fireworks, South Lake...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-23

... Zone; Northern California Annual Fireworks Events, Fourth of July Fireworks, South Lake Tahoe Gaming... will enforce Lights on the Lake Fireworks Display safety zone for South Lake Tahoe, from 8:30 a.m. on... the Lake Fireworks in 33 CFR 165.1191 on July 4, 2010, from 8:30 a.m. on July 1, 2010 through 10 p.m...

Fish Mercury Loads and Lake Productivity Are Not Impacted by Wildland Fire in Northern Minnesota

NASA Astrophysics Data System (ADS)

Riggs, C.; Kolka, R. K.; Nater, E. A.; Witt, E.; Wickman, T.; Woodruff, L. G.; Butcher, J.

2016-12-01

Wildland fire can significantly alter mercury (Hg) cycling on land and in adjacent aquatic environments. In addition to enhancing local atmospheric Hg deposition, fire can influence terrestrial movement of Hg and other elements into lakes via runoff from burned upland soil. However, the impact of fire on water quality and the accumulation of Hg in fish remains equivocal. We investigated the effects of fire - specifically a low severity prescribed fire and moderate severity wildfire - on young-of-the-year yellow perch (Perca flavescens) and lake chemistry in two small remote watersheds in the Boundary Waters Canoe Area Wilderness in northeastern Minnesota using a paired watershed approach (fire-impacted vs. control watershed). Prior to fire, surface soil in the two study watersheds contained significant loads of Hg, mainly from atmospheric deposition. We expected fire to increase transport and deposition of Hg from smoke and burned soil into the fire-impacted lake, leading to changes in lake productivity and fish Hg loads. In contrast to our prediction, and despite significant effects of the moderate severity wildfire fire on upland soil Hg stocks, fish Hg accumulation and lake productivity were not affected by fire. Instead, climate and lake water levels were the strongest predictors of lake chemistry and fish responses in our study lakes. Our results suggest that low to moderate severity wildland fire does not alter lake productivity nor Hg accumulation in young-of-the-year yellow perch in these small, shallow lakes in the northern deciduous and boreal forest region. The effect of a high severity fire remains to be tested.

76 FR 37650 - Safety Zone; Northern California Annual Fireworks Events, Fourth of July Fireworks, South Lake...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-28

... Zone; Northern California Annual Fireworks Events, Fourth of July Fireworks, South Lake Tahoe Gaming... will enforce the safety zone for the annual Fourth of July Fireworks, South Lake Tahoe Gaming Alliance (Lights on the Lake Fireworks Display). This action is necessary to control vessel traffic and to ensure...

Predicting exotic earthworm distribution in the northern Great Lakes region

Treesearch

Lindsey M. Shartell; Erik A. Lilleskov; Andrew J. Storer

2013-01-01

Identifying influences of earthworm invasion and distribution in the northern Great Lakes is an important step in predicting the potential extent and impact of earthworms across the region. The occurrence of earthworm signs, indicating presence in general, and middens, indicating presence of Lumbricus terrestris exclusively, in the Huron Mountains...

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.

Lake Powell

NASA Technical Reports Server (NTRS)

2007-01-01

The white ring around Lake Powell tells the story. The surface is down 98 feet. This is critical, because Powell, Lake Mead, and other lakes along the Colorado River provide water for millions of people in five states. We are in the eighth year of a drought on the Colorado River. This year was the driest year ever reported in Southern California, and there is a severe drought in Northern California, down to less than 30-percent of snow pack. This ASTER image of part of Lake Powell was acquired in 2001. The gray area depicts the shrunken, reduced 2007 lake extent compared to the extended, larger black area in 2001.

The image covers an area of 24 x 30 km, and is centered near 37.1 degrees north latitude, 111.3 degrees west longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Chemical Evolution of Groundwater Near a Sinkhole Lake, Northern Florida: 1. Flow Patterns, Age of Groundwater, and Influence of Lake Water Leakage

NASA Astrophysics Data System (ADS)

Katz, Brian G.; Lee, Terrie M.; Plummer, L. Niel; Busenberg, Eurybiades

1995-06-01

Leakage from sinkhole lakes significantly influences recharge to the Upper Floridan aquifer in poorly confined sediments in northern Florida. Environmental isotopes (oxygen 18, deuterium, and tritium), chlorofluorocarbons (CFCs: CFC-11, CCl3F; CFC-12, CCl2F2; and CFC-113, C2Cl3F3), and solute tracers were used to investigate groundwater flow patterns near Lake Barco, a seepage lake in a mantled karst setting in northern Florida. Stable isotope data indicated that the groundwater downgradient from the lake contained 11-67% lake water leakage, with a limit of detection of lake water in groundwater of 4.3%. The mixing fractions of lake water leakage, which passed through organic-rich sediments in the lake bottom, were directly proportional to the observed methane concentrations and increased with depth in the groundwater flow system. In aerobic groundwater upgradient from Lake Barco, CFC-modeled recharge dates ranged from 1987 near the water table to the mid 1970s for water collected at a depth of 30 m below the water table. CFC-modeled recharge dates (based on CFC-12) for anaerobic groundwater downgradient from the lake ranged from the late 1950s to the mid 1970s and were consistent with tritium data. CFC-modeled recharge dates based on CFC-11 indicated preferential microbial degradation in anoxic waters. Vertical hydraulic conductivities, calculated using CFC-12 modeled recharge dates and Darcy's law, were 0.17, 0.033, and 0.019 m/d for the surficial aquifer, intermediate confining unit, and lake sediments, respectively. These conductivities agreed closely with those used in the calibration of a three-dimensional groundwater flow model for transient and steady state flow conditions.

Chemical Analyses of Pre-Holocene Rocks from Medicine Lake Volcano and Vicinity, Northern California

USGS Publications Warehouse

Donnelly-Nolan, Julie M.

2008-01-01

Chemical analyses are presented in an accompanying table (Table 1) for more than 600 pre-Holocene rocks collected at and near Medicine Lake Volcano, northern California. The data include major-element X-ray fluorescence (XRF) analyses for all of the rocks plus XRF trace element data for most samples, and instrumental neutron activation analysis (INAA) trace element data for many samples. In addition, a limited number of analyses of Na2O and K2O by flame photometry (FP) are included as well assome wet chemical analyses of FeO, H2O+/-, and CO2. Latitude and longitude location information is provided for all samples. This data set is intended to accompany the geologic map of Medicine Lake Volcano (Donnelly-Nolan, in press); map unit designations are given for each sample collected from the map area.

Subsurface Constraints on Late Cenozoic Basin Geometry in Northern Fish Lake Valley and Displacement Transfer Along the Northern Fish Lake Valley Fault Zone, Western Nevada

NASA Astrophysics Data System (ADS)

Mueller, N.; Kerstetter, S. R.; Katopody, D. T.; Oldow, J. S.

2016-12-01

The NW-striking, right-oblique Fish Lake Valley fault zone (FLVFZ) forms the northern segment of the longest active structure in the western Great Basin; the Death Valley - Furnace Creek - Fish Lake Valley fault system. Since the mid-Miocene, 50 km of right-lateral displacement is documented on the southern FLVFZ and much of that displacement was and is transferred east and north on active WNW left-lateral faults. Prior to the Pliocene, displacement was transferred east and north on a low-angle detachment. Displacement on the northern part of the FLVFZ continues and is transferred to a fanned array of splays striking (west to east) WNW, NNW, ENE and NNE. To determine the displacement budget on these structures, we conducted a gravity survey to determine subsurface basin morphology and its relation to active faults. Over 2450 stations were collected and combined with existing PACES and proprietary data for a total of 3388 stations. The data were terrain corrected and reduced to a 2.67 g/cm3 density to produce a residual complete Bouguer anomaly. The eastern part of northern Fish Lake Valley is underlain by several prominent gravity lows forming several sub-basins with maximum RCBA values ranging from -24 to -28 mGals. The RCBA was inverted for depth using Geosoft Oasis Montaj GM-SYS 3D modeling software. Density values for the inversion were constrained by lithologic and density logs from wells that penetrate the entire Cenozoic section into the Paleozoic basement. Best fitting gravity measurements taken at the wellheads yielded an effective density of 2.4 g/cm3 for the basin fill. Modeled basement depths range between 2.1 to 3 km. The sub-basins form an arc opening to the NW and are bounded by ENE and NNE faults in the south and NS to NNW in the north. At the northern end of the valley, the faults merge with ENE left-lateral strike slip faults of the Mina deflection, which carries displacement to NW dextral strike-slip faults of the central Walker Lane.

Multiscale Terrain Analysis of Multibeam Bathymetry Data for Lake Trout Spawning Habitat Mapping in the Drummond Island Refuge, northern Lake Huron

NASA Astrophysics Data System (ADS)

Wattrus, N. J.; Binder, T.

2012-12-01

Until the 1950s, lake trout supported a valuable commercial fishery in the Great Lakes. The introduction of sea lamprey into the Great Lakes and overfishing resulted in the loss of most populations. Despite consistent stocking efforts since the 1960s, restoration of these populations has been slow. The reasons are numerous, but may be related to differences in the spawning behavior between hatchery and wild trout. A four-year study initiated in 2010, utilizes acoustic telemetry to characterize and compare the spawning behaviors of hatchery and wild lake trout in the Drummond Island Refuge in northern Lake Huron. In this project, the movement of tagged fish are monitored by an array of over 125 lake floor hydrophones during the fall spawning period. Fish behavior is overlaid over detailed bathymetric and substrate data and compared with environmental variables (e.g. water temperature, wind speed and direction, and wave height and direction) to develop a conceptual behavioral model. Sites suspected of being spawning sites based upon telemetry data are verified through the use of divers and trapping eggs and fry. Prior to this study, the factors that influenced how the spawning fish utilize the lake floor shoals have been poorly understood. Among the factors thought to impact spawning success were: bathymetry and substrate composition. Diver and telemetry data suggest that the fish(both hatchery raised and wild) are particularly attracted to rocky substrates and that fragment size is important. High resolution multibeam bathymetric surveys conducted in 2010 and 2011 have been used to characterize the shape and composition of the lake floor in the study area. Classification of the substrate is a labor intensive process requiring divers, drop cameras and sediment sampling. To improve this, the traditional approach has been to use supervised and unsupervised classification techniques that are based upon measured acoustic backscatter from an echosounder or sidescan sonar

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

Spawning site fidelity of wild and hatchery lake trout (Salvelinus namaycush) in northern Lake Huron

USGS Publications Warehouse

Binder, Thomas; Riley, Stephen C.; Holbrook, Christopher; Hansen, Michael J.; Bergstedt, Roger A.; Bronte, Charles R.; He, Ji; Krueger, Charles C.

2016-01-01

Fidelity to high-quality spawning sites helps ensure that adults repeatedly spawn at sites that maximize reproductive success. Fidelity is also an important behavioural characteristic to consider when hatchery-reared individuals are stocked for species restoration, because artificial rearing environments may interfere with cues that guide appropriate spawning site selection. Acoustic telemetry was used in conjunction with Cormack–Jolly–Seber capture–recapture models to compare degree of spawning site fidelity of wild and hatchery-reared lake trout (Salvelinus namaycush) in northern Lake Huron. Annual survival was estimated to be between 77% and 81% and did not differ among wild and hatchery males and females. Site fidelity estimates were high in both wild and hatchery-reared lake trout (ranging from 0.78 to 0.94, depending on group and time filter), but were slightly lower in hatchery-reared fish than in wild fish. The ecological implication of the small difference in site fidelity between wild and hatchery-reared lake trout is unclear, but similarities in estimates suggest that many hatchery-reared fish use similar spawning sites to wild fish and that most return to those sites annually for spawning.

Spatial distribution of pelagic fish larvae in the northern main basin of Lake Huron

USGS Publications Warehouse

Roseman, Edward F.; O'Brien, Timothy P.

2013-01-01

Larval fish occurrence in inshore and offshore zones in the northern main basin of Lake Huron was assessed during 2007 as part of a larger ecological examination of Lake Huron foodwebs and habitats. Day and night collections using neuston and conical nets at inshore (1.5–15 m depths) and offshore (37 and 91 m depths) locations at De Tour and Hammond Bay to assess the abundance, phenology, and spatial distribution of pelagic ichthyoplankton during spring and early summer were made. In general, densities of larval fishes were higher at De Tour than Hammond Bay during daytime neuston net collections, with the exception of Longnose Sucker, which were only collected at Hammond Bay. Lake Whitefish, Burbot, and Rainbow Smelt dominated inshore catches in early spring with Cisco, Deepwater Sculpin, Emerald Shiner, Bloater, Slimy Sculpin, Ninespine Stickleback, and Yellow Perch larvae also collected.Nighttime nearshore and offshore sampling revealed that Rainbow Smelt and Burbot larvae were present in relatively high abundances compared to inshore densities. Concentrations of larvae of deepwater demersal fishes such as Lake Whitefish and Deepwater Sculpin suggest that inshore zones in northern Lake Huron are important nursery habitats emphasizing a critical production and recruitment linkage between inshore and deepwater zones.

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)

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.

2015-01-01

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.

Geologic framework and hydrogeologic characteristics of the outcrops of the Edwards and Trinity aquifers, Medina Lake area, Texas

USGS Publications Warehouse

Small, Ted A.; Lambert, Rebecca B.

1998-01-01

The Trinity aquifer, which crops out in the northern part of the Medina Lake area and underlies the Edwards aquifer in the southern part, is much less permeable and productive than the Edwards aquifer. Where the Trinity aquifer underlies the Edwards, the Trinity acts as a lower confining unit on the Edwards.

Mercury and water level fluctuations in lakes of northern Minnesota

USGS Publications Warehouse

Larson, James H.; Maki, Ryan P; Christensen, Victoria G.; Sandheinrich, Mark B.; LeDuc, Jaime F.; Kissane, Claire; Knights, Brent C.

2017-01-01

Large lake ecosystems support a variety of ecosystem services in surrounding communities, including recreational and commercial fishing. However, many northern temperate fisheries are contaminated by mercury. Annual variation in mercury accumulation in fish has previously been linked to water level (WL) fluctuations, opening the possibility of regulating water levels in a manner that minimizes or reduces mercury contamination in fisheries. Here, we compiled a long-term dataset (1997-2015) of mercury content in young-of-year Yellow Perch (Perca flavescens) from six lakes on the border between the U.S. and Canada and examined whether mercury content appeared to be related to several metrics of WL fluctuation (e.g., spring WL rise, annual maximum WL, and year-to-year change in maximum WL). Using simple correlation analysis, several WL metrics appear to be strongly correlated to Yellow Perch mercury content, although the strength of these correlations varies by lake. We also used many WL metrics, water quality measurements, temperature and annual deposition data to build predictive models using partial least squared regression (PLSR) analysis for each lake. These PLSR models showed some variation among lakes, but also supported strong associations between WL fluctuations and annual variation in Yellow Perch mercury content. The study lakes underwent a modest change in WL management in 2000, when winter WL minimums were increased by about 1 m in five of the six study lakes. Using the PLSR models, we estimated how this change in WL management would have affected Yellow Perch mercury content. For four of the study lakes, the change in WL management that occurred in 2000 likely reduced Yellow Perch mercury content, relative to the previous WL management regime.

A lake-centric geospatial database to guide research and inform management decisions in an Arctic watershed in northern Alaska experiencing climate and land-use changes

USGS Publications Warehouse

Jones, Benjamin M.; Arp, Christopher D.; Whitman, Matthew S.; Nigro, Debora A.; Nitze, Ingmar; Beaver, John; Gadeke, Anne; Zuck, Callie; Liljedahl, Anna K.; Daanen, Ronald; Torvinen, Eric; Fritz, Stacey; Grosse, Guido

2017-01-01

Lakes are dominant and diverse landscape features in the Arctic, but conventional land cover classification schemes typically map them as a single uniform class. Here, we present a detailed lake-centric geospatial database for an Arctic watershed in northern Alaska. We developed a GIS dataset consisting of 4362 lakes that provides information on lake morphometry, hydrologic connectivity, surface area dynamics, surrounding terrestrial ecotypes, and other important conditions describing Arctic lakes. Analyzing the geospatial database relative to fish and bird survey data shows relations to lake depth and hydrologic connectivity, which are being used to guide research and aid in the management of aquatic resources in the National Petroleum Reserve in Alaska. Further development of similar geospatial databases is needed to better understand and plan for the impacts of ongoing climate and land-use changes occurring across lake-rich landscapes in the Arctic.

Trophic ecology of largemouth bass and northern pike in allopatric and sympatric assemblages in northern boreal lakes

USGS Publications Warehouse

Soupir, Craig A.; Brown, Michael L.; Kallemeyn, Larry W.

2000-01-01

Largemouth bass (Micropterus salmoides) and northern pike (Esox lucius) are top predators in the food chain in most aquatic environments that they occupy; however, limited information exists on species interactions in the northern reaches of largemouth bass distribution. We investigated the seasonal food habits of allopatric and sympatric assemblages of largemouth bass and northern pike in six interior lakes within Voyageurs National Park, Minnesota. Percentages of empty stomachs were variable for largemouth bass (38-54%) and northern pike (34.7-66.7%). Fishes (mainly yellow perch, Perca flavescens) comprised greater than 60% (mean percent mass, MPM) of the northern pike diet during all seasons in both allopatric and sympatric assemblages. Aquatic insects (primarily Odonata and Hemiptera) were important in the diets of largemouth bass in all communities (0.0-79.7 MPM). Although largemouth bass were observed in the diet of northern pike, largemouth bass apparently did not prey on northern pike. Seasonal differences were observed in the proportion of aquatic insects (P = 0.010) and fishes (P = 0.023) in the diets of northern pike and largemouth bass. Based on three food categories, jackknifed classifications correctly classified 77 and 92% of northern pike and largemouth bass values, respectively. Percent resource overlap values were biologically significant (greater than 60%) during at least one season in each sympatric assemblage, suggesting some diet overlap.

Temperature calibration and phylogenetically distinct distributions for freshwater alkenones: Evidence from northern Alaskan lakes

NASA Astrophysics Data System (ADS)

Longo, William M.; Theroux, Susanna; Giblin, Anne E.; Zheng, Yinsui; Dillon, James T.; Huang, Yongsong

2016-05-01

Alkenones are a class of unsaturated long-chain ketone biomarkers that have been used to reconstruct sea surface temperature and, more recently, continental temperature, by way of alkenone unsaturation indices (e.g. U37K and U37K‧). Alkenones are frequently found in brackish and saline lakes, however species effects confound temperature reconstructions when multiple alkenone-producing species with different temperature responses are present. Interestingly, available genetic data indicate that numerous freshwater lakes host a distinct phylotype of alkenone-producing haptophyte algae (the Group I or Greenland phylotype), providing evidence that species effects may be diminished in freshwater lakes. These findings encourage further investigation of alkenone paleotemperature proxies in freshwater systems. Here, we investigated lakes from northern Alaska (n = 35) and show that alkenones commonly occurred in freshwater lakes, where they featured distinct distributions, characterized by dominant C37:4 alkenones and a series of tri-unsaturated alkenone isomers. The distributions were characteristic of Group I-type alkenone distributions previously identified in Greenland and North America. Our analysis of suspended particulate matter from Toolik Lake (68° 38‧N, 149° 36‧W) yielded the first in situ freshwater U37K calibration (U37K = 0.021 * T - 0.68; r2 = 0.85; n = 52; RMSE = ±1.37 °C). We explored the environmental significance of the tri-unsaturated isomers using our northern Alaskan lakes dataset in conjunction with new data from haptophyte cultures and Canadian surface sediments. Our results show that these temperature-sensitive isomers are biomarkers for the Group I phylotype and indicators of multiple-species effects. Together, these findings highlight freshwater lakes as valuable targets for continental alkenone-based paleotemperature reconstructions and demonstrate the significance of the recently discovered tri-unsaturated isomers.

Common Loon (Gavia immer) eggshell thickness and egg volume vary with acidity of nest lake in northern Wisconsin

USGS Publications Warehouse

Pollentier, C.D.; Kenow, K.P.; Meyer, M.W.

2007-01-01

Environmental acidification has been associated with factors that may negatively affect reproduction in many waterbirds. Declines in lake pH can lead to reductions in food availability and quality, or result in the altered availability of toxic metals, such as mercury. A recent laboratory study conducted by the U.S. Geological Survey and the Wisconsin Department of Natural Resources indicated that Common Loon (Gavia immer) chicks hatched from eggs collected on acidic lakes in northern Wisconsin may be less responsive to stimuli and exhibit reduced growth compared to chicks from neutral-pH lakes. Here we report on the relation between Common Loon egg characteristics (eggshell thickness and egg volume) and lake pH, as well as eggshell methylmercury content. Eggs (N = 84) and lake pH measurements were obtained from a four county region of northern Wisconsin. Egg-shells were 3-4% thinner on lakes with pH ??? 6.3 than on neutral-pH lakes and this relation was linear across the pH range investigated (P 0.05, n.s.) or lake pH. Results suggest that low lake pH may be associated with thinner eggshells and reduced egg volume in Common Loons. We speculate on the mechanisms that may lead to this phenomeno.

Acidity of Lakes and Impoundments in North-Central Minnesota

Treesearch

Elon S. Verry

1981-01-01

Measurements of lake and impoundment pH for several years, intensive sampling within years, and pH-calcium plots verify normal pH levels and do not show evidence of changes due to acid precipitation. These data in comparison with general lake data narrow the northern Lake States area in which rain or snow may cause lake acidification.

The influence of landscape position on lake chemical responses to drought in northern Wisconsin

USGS Publications Warehouse

Webster, K.E.; Kratz, T.K.; Bowser, C.J.; Magnuson, J.J.; Rose, W.J.

1996-01-01

Climatic shifts to drier conditions during drought alter the hydrologic pathways of water and solute flow to aquatic ecosystems. We examined differences in drought-induced trends in the semiconservative cations, Ca+Mg, in seven northern Wisconsin lakes. These spanned the range of hydrologic settings in the region, including hydraulically mounded, groundwater flowthrough, and groundwater-discharge lakes. Parallel increases in concentration across the seven lakes during drought were attributable to evapoconcentration. However, we observed divergent trends for mass, which better reflects altered solute flux by accounting for changes in lake volume. Ca+Mg mass increased in three groundwater-dominated lakes as precipitation inputs were low and groundwater discharging from longer flowpaths became proportionately more important. In contrast, decreases in Ca+Mg mass for two precipitation-dominated lakes reflected diminished inputs of solute-rich groundwater. Landscape position, defined by the spatial position of a lake within a hydrologic flow system, accounted for the divergence in chemical responses to drought.

Northern Great Basin Seasonal Lakes: Vulnerability to Climate Change.

NASA Astrophysics Data System (ADS)

Russell, M.; Eitel, J.

2017-12-01

Seasonal alkaline lakes in southeast Oregon, northeast California, and northwest Nevada serve as important habitat for migrating birds utilizing the Pacific Flyway, as well as local plant and animal communities. Despite their ecological importance, and anecdotal suggestions that these lakes are becoming less reliable, little is known about the vulnerability of these lakes to climate change. Our research seeks to understand the vulnerability of Northern Great Basin seasonal lakes to climate change. For this, we will be using historical information from the European Space Agency's Global Surface Water Explorer and the University of Idaho's gridMET climate product, to build a model that allows estimating surface water extent and timing based on climate variables. We will then utilize downscaled future climate projections to model surface water extent and timing in the coming decades. In addition, an unmanned aerial system (UAS) will be utilized at a subset of dried basins to obtain precise 3D bathymetry and calculate water volume hypsographs, a critical factor in understanding the likelihood of water persistence and biogeochemical habitat suitability. These results will be incorporated into decision support tools that land managers can utilize in water conservation, wildlife management, and climate mitigation actions. Future research may pair these forecasts with animal movement data to examine fragmentation of migratory corridors and species-specific impacts.

Identification of lake trout Salvelinus namaycush spawning habitat in northern Lake Huron using high-resolution satellite imagery

USGS Publications Warehouse

Grimm, Amanda G.; Brooks, Colin N.; Binder, Thomas R.; Riley, Stephen C.; Farha, Steve A.; Shuchman, Robert A.; Krueger, Charles C.

2016-01-01

The availability and quality of spawning habitat may limit lake trout recovery in the Great Lakes, but little is known about the location and characteristics of current spawning habitats. Current methods used to identify lake trout spawning locations are time- and labor-intensive and spatially limited. Due to the observation that some lake trout spawning sites are relatively clean of overlaying algae compared to areas not used for spawning, we suspected that spawning sites could be identified using satellite imagery. Satellite imagery collected just before and after the spawning season in 2013 was used to assess whether lake trout spawning habitat could be identified based on its spectral characteristics. Results indicated that Pléiades high-resolution multispectral satellite imagery can be successfully used to estimate algal coverage of substrates and temporal changes in algal coverage, and that models developed from processed imagery can be used to identify potential lake trout spawning sites based on comparison of sites where lake trout eggs were and were not observed after spawning. Satellite imagery is a potential new tool for identifying lake trout spawning habitat at large scales in shallow nearshore areas of the Great Lakes.

Climate-landform effects on lateglacial vegetation pattern in northeastern Tuchola Pinewoods (northern Poland): multiproxy evidence from the Lake Czechowskie catchment, northern Poland.

NASA Astrophysics Data System (ADS)

Noryśkiewicz, Agnieszka M.; Kordowski, Jarosław; Tyszkowski, Sebastian; Kramkowski, Mateusz; Zawiska, Izabela; Rzodkiewicz, Monika; Mirosław-Grabowska, Joanna; Ott, Florian; Słowiński, Michał; Obremska, Milena; Błaszkiewicz, Mirosław; Brauer, Achim

2016-04-01

The study area is located in northern Poland in the northeastern part of Tuchola Pinewoods in a young glacially formed and diversified landscape. It comprises the entire lake catchment of Lake Czechowskie (19.76 km2), which comprises a second lake upstream as well as a palaeolake (Trzechowskie) located between the two present-day lakes. Biogenic sediments from eight cores were studied by multiproxy analyses to reconstruct the environmental changes and climate signals during the last Late Glacial and early Holocene. The cores were collected along a W-E transect from Głęboczek Lake to the Czechowskie Lake and were located in different topographic positions (deepest and shallow part of the lake, old lake-bed plains and paleolakes) with a maximum distance of 2.2 km. Detailed and high resolution analyses (pollen, diatoms, cladocera, stable isotopes, geochemistry, varve chronology and radiocarbon dating) to identify the main stages in the development of the natural environment were made. Palynological data indicate melting of the buried ice blocks and the following the onset of biogenic lacustrine sedimentation. The general pattern of vegetation changes in all profiles is similar and includes Late Glacial steppe-tundra plant communities at the onset of organic lake sedimentation. The palynological record of the most profiles shows a high participation of seabuckthorn (Hippophae) in the initial stadium of vegetation history. The lack of this succession in the most western core (Głęboczek Lake) indicates a later period of melt-out processes of the buried dead-ice blocks in the Głęboczek Lake basin. The thickness and type of the accumulated sediments differ significantly during the Bolling-Alerod complex and Younger Dryas Period between our sites. These differences are also reflected in variations of plant species among the different sites. The comparison of different profiles within one catchment allows us to distinguish site specific local responses to climate

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.

Expansion rate and geometry of floating vegetation mats on the margins of thermokarst lakes, northern Seward Peninsula, Alaska, USA

USGS Publications Warehouse

Parsekian, A.D.; Jones, Benjamin M.; Jones, M.; Grosse, G.; Walter, Anthony K.M.; Slater, L.

2011-01-01

Investigations on the northern Seward Peninsula in Alaska identified zones of recent (<50years) permafrost collapse that led to the formation of floating vegetation mats along thermokarst lake margins. The occurrence of floating vegetation mat features indicates rapid degradation of near-surface permafrost and lake expansion. This paper reports on the recent expansion of these collapse features and their geometry is determined using geophysical and remote sensing measurements. The vegetation mats were observed to have an average thickness of 0.57m and petrophysical modeling indicated that gas content of 1.5-5% enabled floatation above the lake surface. Furthermore, geophysical investigation provides evidence that the mats form by thaw and subsidence of the underlying permafrost rather than terrestrialization. The temperature of the water below a vegetation mat was observed to remain above freezing late in the winter. Analysis of satellite and aerial imagery indicates that these features have expanded at maximum rates of 1-2myr-1 over a 56year period. Including the spatial coverage of floating 'thermokarst mats' increases estimates of lake area by as much as 4% in some lakes. ?? 2011 John Wiley & Sons, Ltd.

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…

View of the Salt Lake City, Utah area

NASA Technical Reports Server (NTRS)

1973-01-01

An oblique view of the Salt Lake City, Utah area as photographed from Earth orbit by one of the six lenses of the Itek-furnished S190-A Multispectral Photographic Facility Experiment aboard the Skylab space station. Approximately two-thirds of the Great Salt Lake is in view. The smaller body of water south of Salt Lake City is Utah Lake. The Wasatch Range is on the east side of the Great Salt Lake.

Spatio-temporal analysis of gyres in oriented lakes on the Arctic Coastal Plain of northern Alaska based on remotely sensed images

USGS Publications Warehouse

Zhan, Shengan; Beck, Richard A.; Hinkel, Kenneth M.; Liu, Hongxing; Jones, Benjamin M.

2014-01-01

The formation of oriented thermokarst lakes on the Arctic Coastal Plain of northern Alaska has been the subject of debate for more than half a century. The striking elongation of the lakes perpendicular to the prevailing wind direction has led to the development of a preferred wind-generated gyre hypothesis, while other hypotheses include a combination of sun angle, topographic aspect, and/or antecedent conditions. A spatio-temporal analysis of oriented thermokarst lake gyres with recent (Landsat 8) and historical (Landsat 4, 5, 7 and ASTER) satellite imagery of the Arctic Coastal Plain of northern Alaska indicates that wind-generated gyres are both frequent and regionally extensive. Gyres are most common in lakes located near the Arctic coast after several days of sustained winds from a single direction, typically the northeast, and decrease in number landward with decreasing wind energy. This analysis indicates that the conditions necessary for the Carson and Hussey (1962) wind-generated gyre for oriented thermokarst lake formation are common temporally and regionally and correspond spatially with the geographic distribution of oriented lakes on the Arctic Coastal Plain. Given an increase in the ice-free season for lakes as well as strengthening of the wind regime, the frequency and distribution of lake gyres may increase. This increase has implications for changes in northern high latitude aquatic ecosystems, particularly if wind-generated gyres promote permafrost degradation and thermokarst lake expansion.

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. (a...

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. (a...

Spatiotemporal climatic, hydrological, and environmental variations based on records of annually laminated lake sediments from northern Poland

NASA Astrophysics Data System (ADS)

Tylmann, W.; Blanke, L.; Kinder, M.; Loewe, T.; Mayr, C.; Ohlendorf, C.; Zolitschka, B.

2009-12-01

In northern Poland there is the unique opportunity to compare varved lake sediment records with distinct climatic trends along a 700 km long W-E transect. Annually laminated Holocene sediment sequences from Lake Lubinskie, Lake Suminko, Lake Lazduny, and Lake Szurpily were cored for high-resolution multiproxy climate and environmental reconstruction in the framework of the Polish-German project “Northern Polish Lake Research” (NORPOLAR). First results from a 139 cm long gravity core of Lake Lazduny (53°51.4’N, 21°57.3’E) document deposition of an organic (mean organic matter: 13.9%; mean biogenic opal: 9.8%) and highly carbonaceous gyttja (mean calcite content: 61.6%). The finely laminated sediment consists of biochemical varves. Pale spring/summer layers composed of autochthonous carbonates alternate with dark fall/winter layers made of organic and minerogenic detritus. The established chronology for the last 1500 calendar-years is based on thin section analysis supported by independent radiometric dating (C-14, Pb-210). Sedimentological, geochemical and stable isotope analyses were carried out with a decadal temporal resolution. Additionally, non-destructive and high-resolution XRF scanning data reveal a rhythmic variation in the Ca content that reflects seasonal calcite deposition. Redox-sensitive elements like Fe, Mn and S are interpreted to be the response to mean winter temperatures: colder winter temperatures → extended lake ice cover → intensification of meromixis → increased Fe/Mn ratio. In turn, these parameters can be linked to NAO (North Atlantic Oscillation) variability, because a negative NAO is related to colder and drier conditions in northeastern Europe. Climate variability is also mirrored by the δ13C record of the endogenic calcite fraction. In mid-latitude lakes calcite precipitation is dominated by productivity-controlled consumption of the dissolved inorganic carbon (DIC) pool. Thus the δ13C record potentially provides a

76 FR 37646 - Safety Zone; Northern California Annual Fireworks Events, Fourth of July Fireworks, Lake Tahoe, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-28

... Zone; Northern California Annual Fireworks Events, Fourth of July Fireworks, Lake Tahoe, CA AGENCY... annual safety zone for the Fourth of July Fireworks, Lake Tahoe, California, located off Incline Village...,000 foot safety zone for the annual Fourth of July Fireworks Display in 33 CFR 165.1191 on July 4...

Shifting balance of thermokarst lake ice regimes across the Arctic Coastal Plain of northern Alaska

USGS Publications Warehouse

Arp, Christopher D.; Jones, Benjamin M.; Lu, Zong; Whitman, Matthew S.

2012-01-01

The balance of thermokarst lakes with bedfast- and floating-ice regimes across Arctic lowlands regulates heat storage, permafrost thaw, winter-water supply, and over-wintering aquatic habitat. Using a time-series of late-winter synthetic aperture radar (SAR) imagery to distinguish lake ice regimes in two regions of the Arctic Coastal Plain of northern Alaska from 2003–2011, we found that 18% of the lakes had intermittent ice regimes, varying between bedfast-ice and floating-ice conditions. Comparing this dataset with a radar-based lake classification from 1980 showed that 16% of the bedfast-ice lakes had shifted to floating-ice regimes. A simulated lake ice thinning trend of 1.5 cm/yr since 1978 is believed to be the primary factor driving this form of lake change. The most profound impacts of this regime shift in Arctic lakes may be an increase in the landscape-scale thermal offset created by additional lake heat storage and its role in talik development in otherwise continuous permafrost as well as increases in over-winter aquatic habitat and winter-water supply.

Lake ecosystem response to rapid lateglacial climate changes in lake sediments from northern Poland

NASA Astrophysics Data System (ADS)

Słowiński, Michał; Zawiska, Izabela; Ott, Florian; Noryśkiewicz, Agnieszka M.; Apolinarska, Karina; Lutyńska, Monika; Michczyńska, Danuta J.; Brauer, Achim; Wulf, Sabine; Skubała, Piotr; Błaszkiewicz, Mirosław

2013-04-01

During the Late Glacial Period environment changes were triggered by climatic oscillations which in turn controlled processes like, for example, permafrost thawing, vegetation development and ground water circulation. These environmental changes are ideally recorded in lake sediments and thus can be reconstructed applying a multi-poxy approach. Here, we present the results from the Trzechowskie paleolake, located in the northern Polish lowlands (eastern part of the Pomeranian Lakeland). The site is situated on the outwash plain of the Wda River, which was formed during the Pomeranian phase of the Vistulian glaciation ca 16,000 14C yrs BP. The depression of the Trzechowskie lake basin formed after melting of a buried ice block during the Allerød (13903±170 cal yrs BP). We reconstructed environmental changes in the Trzechowskie paleolake and its catchment using biotic proxies (macrofossils, pollen, cladocera, diatoms, oribatidae mite) and geochemical proxies (δ18O, δ13C, loss-on-ignition (LOI), CaCO3 content). In addition, we carried out µ-XRF element core scanning. The chronology has been established by means of biostratigraphyAMS14C dating on plant macro remains, varve counting in laminated intervals and the late Allerød Laacher See Tephra isochrone. Our results showed that biogenic accumulation in the lake started during the Bølling. Development of coniferous forest during the Allerød with dominance of Pinus sylvestris lead to leaching of carbonates in the catchment due to low pH increasing the flux of Ca ions into the lake. In consequence calcite precipitating in the lake increased as evidences by increasing CaCO3 contents. Both biotic and physical proxies clearly reflect the rapid decrease in productivity at the onset of the Younger Dryas. We compare the data from the Trzechowskie paleolake with the Meerfelder Maar and Rehwiese lake records based on tephrochronological synchronization using the Laacher See Tephra. This study is a contribution to the

Artificial regeneration of northern red oak in the Lake States with a light shelterwood: a departure from tradition

Treesearch

Ronald M. Teclaw; J. G. Isebrands

1993-01-01

Artificial regeneration of northern red oak is difficult to achieve in the Lake States. A replicated study was established in northern Wisconsin in 1990 to determine the effect of overstory density and understory competition on the performance of bareroot and containerized northern red oak seedlings on a dry-mesic site. The relationship between seedling performance and...

Lake Chad, Chad, Africa

NASA Technical Reports Server (NTRS)

1992-01-01

Hydrologic and ecologic changes in the Lake Chad Basin are shown in this Oct 1992 photograph. In space photo documentation, Lake Chad was at its greatest area extent (25,000 sq. km.) during Gemini 9 in June 1966 (see S66-38444). Its reduction during the severe droughts from 1968 to 1974 was first noted during Skylab (1973-1974). After the drought began again in 1982, the lake reached its minimum extent (1,450 sq. km.) in Space Shuttle photographs taken in 1984 and 1985. In this STS-52 photograph, Lake Chad has begun to recover. The area of the open water and interdunal impoundments in the southern basin (the Chari River Basin) is estimated to be 1,900 to 2100 sq. km. Note the green vegetation in the valley of the K'Yobe flow has wetted the northern lake basin for the first time in several years. There is evidence of biomass burning south of the K'Yobe Delta and in the vegetated interdunal areas near the dike in the center of the lake. Also note the dark 'Green Line' of the Sahel (the g

Benthic bioindicators from the lakes of Northern Yakutia (Siberia, Russia) in paleoclimatic research

NASA Astrophysics Data System (ADS)

Tumanov, O. N.; Nazarova, L. B.; Frolova, L. A.; Pestryakova, L. A.

2012-04-01

High latitude regions are particularly affected by global climate change. Aquatic ecosystems are known to respond quickly and sensitively to such changes (Carpenter et al., 1992; Findlay et al. 2001; Smol et al., 2005). This effect is especially dramatic in regions with continental climates such as Northern and Eastern Siberia. In 2008, Russian-German expedition investigated 33 lakes of Kolyma river basin, North-Eastern Yakutia. The region of investigation is located in the mouth of Kolyma river between approximately 68°2' and 69°4' N and between 159°8' and 161°9' E. It's a most north-eastern region of Yakutia, so it's suitable for paleolimnological investigations. The investigated lakes are situated along the 200 km transect crossing 3 vegetation zones: polygonal tundra, forest tundra and northern taiga. The main aims were establishing a calibration dataset for paleoenvironmental reconstructions by using aquatic organisms, investigation of limnological variables and the influence of the environmental conditions on distribution of aquatic organisms in Yakutian lakes. The modern benthic fauna of the lakes is represented by 89 taxa from 14 taxonomic groups. The most abundant group was Mollusca. The most taxonomically diverse group was Chironomidae. A unique for this region species were discovered, such as Cincinna kamchatica, Physa jarochnovitschae, Colymbetes dolabratus, Ilybius wasastjernae, Xestochironomus sp., Agrypnia sp. etc. Cluster analysis of taxonomical composition of the benthic fauna of these lakes showed high dependency to vegetation zones. The highest levels of hydrobiological indexes (Shannon, Evenness, species richness) were registered in forest tundra. CCA analysis showed that the most influential factors in species distribution were climate-dependant factors, such as mean Tair of July, pH and water depth. Data from taxonomical analysis of Chironomidae group were used for establishing a calibration dataset for paleoenvironmental reconstructions.

Active intra-basin faulting in the Northern Basin of Lake Malawi from seismic reflection data

NASA Astrophysics Data System (ADS)

Shillington, D. J.; Chindandali, P. R. N.; Scholz, C. A.; Ebinger, C. J.; Onyango, E. A.; Peterson, K.; Gaherty, J. B.; Nyblade, A.; Accardo, N. J.; McCartney, T.; Oliva, S. J.; Kamihanda, G.; Ferdinand, R.; Salima, J.; Mruma, A. H.

2016-12-01

Many questions remain about the development and evolution of fault systems in weakly extended rifts, including the relative roles of border faults and intra-basin faults, and segmentation at various scales. The northern Lake Malawi (Nyasa) rift in the East African Rift System is an early stage rift exhibiting pronounced tectonic segmentation, which is defined by 100-km-long border faults. The basins also contain a series of intrabasinal faults and associated synrift sediments. The occurrence of the 2009 Karonga Earthquake Sequence on one of these intrabasinal faults indicates that some of them are active. Here we present new multichannel seismic reflection data from the Northern Basin of the Malawi Rift collected in 2015 as a part of the SEGMeNT (Study of Extension and maGmatism in Malawi aNd Tanzania) project. This rift basin is bound on its east side by the west-dipping Livingstone border fault. Over 650 km of seismic reflection profiles were acquired in the Northern Basin using a 500 to 1540 cu in air gun array and a 1200- to 1500-m seismic streamer. Dip lines image a series of north-south oriented west-dipping intra-basin faults and basement reflections up to 5 s twtt near the border fault. Cumulative offsets on intra-basin faults decrease to the west. The largest intra-basin fault has a vertical displacement of >2 s two-way travel time, indicating that it has accommodated significant total extension. Some of these intra-basin faults offset the lake bottom and the youngest sediments by up to 50 s twtt ( 37 m), demonstrating they are still active. The two largest intra-basin faults exhibit the largest offsets of young sediments and also correspond to the area of highest seismicity based on analysis of seismic data from the 89-station SEGMeNT onshore/offshore network (see Peterson et al, this session). Fault patterns in MCS profiles vary along the basin, suggesting a smaller scale of segmentation of faults within the basin; these variations in fault patterns

Lost Lake Research Natural Area: guidebook supplement 48

Treesearch

Reid Schuller; Bryan Wender

2016-01-01

This guidebook describes major biological and physical attributes of the 155-ha (384-ac) Lost Lake Research Natural Area (RNA), in Jackson County, Oregon. The RNA has been designated because it contains examples of a landslide-dammed lake; and a low-elevation lake with aquatic beds and fringing marsh, surrounded by mixed-conifer forest (ONHAC 2010).

DINKEY LAKES ROADLESS AREA, CALIFORNIA.

USGS Publications Warehouse

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

1984-01-01

The Dinkey Lakes Roadless Area occupies an area of about 184 sq mi on the western slope of the Sierra Nevada, California. The results of a mineral survey show that parts of the 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.

Lake Garda, Italy

NASA Image and Video Library

2001-07-21

This ASTER image was acquired on July 29, 2000 and covers an area of 30 by 57 km in northern Italy. Lake Garda was formed by glaciers during the last Ice Age, and is Italy's largest lake. Lago di Garda lies in the provinces of Verona, Brescia, and Trento, and is 51 kilometers (32 miles) long and from 3 to 18 kilometers (2 to 11 miles) wide. The Sarca is its chief affluent, and the lake is drained southward by the Mincio, which discharges into the Po River. Many villas are situated on its shores. On the peninsula of Sirmione, at the southern end of the lake, are the ruins of a Roman villa and a castle of the Scaligers, an Italian family of the 16th century. The RIGHT image has the land area masked out, and a harsh stretch was applied to the lake values to display variations in sediment load. Also visible are hundreds of boats and their wakes, criss-crossing the lake. The image is centered at 45.6 degrees north latitude, 10.6 degrees east longitude. http://photojournal.jpl.nasa.gov/catalog/PIA02671

Comparison of catch and lake trout bycatch in commercial trap nets and gill nets targeting lake whitefish in northern Lake Huron

USGS Publications Warehouse

Johnson, James E.; Ebener, Mark P.; Gebhardt, Kenneth; Bergstedt, Roger

2004-01-01

We compared seasonal lake whitefish catch rates, lake trout bycatch, and gearinduced lake trout mortality between commercial trap nets and gill nets in north-central Lake Huron. Onboard monitors recorded catches from 260 gill net and 96 trap net lifts from October 1998 through December 1999. Catch rates for lake whitefish were highest in fall for both gear types, reflecting proximity of spawning sites to the study area. Lake whitefish catch rates were also relatively high in spring but low in both gear types in summer. Lake trout were the principal bycatch species in both gears. The lake trout bycatch was lowest in both gear types in fall, highest in gill nets in spring, and highest in trap nets in summer. The ratio of lake trout to legal whitefish (the target species) was highest in summer and lowest in fall in both gear types. The high lake trout ratio in summer was due principally to low catch rates of lake whitefish. All but 3 of 186 live lake trout removed from trap net pots survived for at least two days of observation in laboratory tanks. Therefore, we estimated that post-release survival of trap netted lake trout that had not been entangled in the mesh was 98.4%. In addition, we accounted for stress-induced mortality for lake trout that were live at capture but entangled in the mesh of either gear type. Resulting estimates of lake trout survival were higher in trap nets (87.8%) than in gill nets (39.6%). The number of lake trout killed per lift was highest during summer in trap nets and during spring in gill nets. In trap nets, 85% of dead lake trout were observed to be entangled in the mesh of the pot or tunnels. Survival rates of lake trout in gill nets were higher in our study than reported by others, probably because our nets were hand lifted in a small boat. Our trap net-induced mortality estimates on lake trout were higher than those reported by others because we adjusted our estimates to account for post-release mortality caused by handling and

Critical loads of acidity for 90,000 lakes in northern Saskatchewan: A novel approach for mapping regional sensitivity to acidic deposition

NASA Astrophysics Data System (ADS)

Cathcart, H.; Aherne, J.; Jeffries, D. S.; Scott, K. A.

2016-12-01

Atmospheric emissions of sulphur dioxide (SO2) from large point sources are the primary concern for acidic deposition in western Canada, particularly in the Athabasca Oil Sands Region (AOSR) where prevailing winds may potentially carry SO2 over acid-sensitive lakes in northern Saskatchewan. A novel catchment-scale regression kriging approach was used to assess regional sensitivity and critical loads of acidity for the total lake population of northern Saskatchewan (89,947 lakes). Lake catchments were delineated using Thiessen polygons, and surface water chemistry was predicted for sensitivity indicators (calcium, pH, alkalinity, and acid neutralizing capacity). Critical loads were calculated with the steady state water chemistry model using regression-kriged base cations, sulphate, and dissolved organic carbon concentrations modelled from surface water observations (n > 800) and digital landscape-scale characteristics, e.g., climate, soil, vegetation, landcover, and geology maps. A large region (>13,726 km2) of two or more indicators of acid sensitivity (pH < 6 and acid neutralizing capacity, alkalinity, calcium < 50 μeq L-1) and low critical loads < 5 meq m-2 yr-1 were predicted on the Athabasca Basin. Exceedance of critical loads under 2006 modelled total sulphate deposition was predicted for 12% of the lakes (covering an area of 3742 km2), primarily located on the Athabasca Basin, within 100 km of the AOSR. There have been conflicting scientific reports of impacts from atmospheric emissions from the AOSR; the results of this study suggest that catchments in the Athabasca Basin within 100 km of the AOSR have received acidic deposition in excess of their critical loads and many of them may be at risk of ecosystem damage owing to their sensitivity.

Mapping Of Lake Ice In Northern Europe Using Dual-Polarization RadarSAT-2 Data

NASA Astrophysics Data System (ADS)

Hindberg, Heidi; Malnes, Erik

2013-12-01

In this paper, we investigate the potential of including cross-polarization data in an unsupervised classification method based on SAR data to determine ice extent over lakes in Northern Europe. By introducing cross-pol data we can increase the separability between open water and ice, and we can decrease misclassifications where open water with waves is classified as ice. Cross-pol data also helps with labelling of the classes. However, cross-pol data can decrease the separability between the classes if the ice on the lake is very thin.

A framework for profiling a lake's riparian area development potential

Treesearch

Pamela J. Jakes; Ciara Schlichting; Dorothy H. Anderson

2003-01-01

Some of the greatest challenges for managing residential development occur at the interface between the terrestrial and aquatic ecosystems -in a lake`s riparian area. Land use planners need a framework they can use to identify development hotspots, areas were the next push for development will most likely occur. Lake riparian development profiles provide a framework...

Holocene evolution of lakes in the forest-tundra biome of northern Manitoba, Canada

NASA Astrophysics Data System (ADS)

Hobbs, William O.; Edlund, Mark B.; Umbanhowar, Charles E.; Camill, Philip; Lynch, Jason A.; Geiss, Christoph; Stefanova, Vania

2017-03-01

The late-Quaternary paleoenvironmental history of the western Hudson Bay region of Subarctic Canada is poorly constrained. Here, we present a regional overview of the post-glacial history of eight lakes which span the forest-tundra biome in northern Manitoba. We show that during the penultimate drainage phase of Lake Agassiz the lake water had an estimated pH of ∼6.0, with abundant quillwort (Isöetes spp.) along the lakeshore and littoral zone and some floating green algae (Botryococcus spp. and Pediastrum sp.). Based on multiple sediment proxies, modern lake ontogeny in the region commenced at ∼7500 cal yrs BP. Pioneering diatom communities were shaped by the turbid, higher alkalinity lake waters which were influenced by base cation weathering of the surrounding till following Lake Agassiz drainage. By ∼7000 cal yrs BP, soil development and Picea spp. establish and the lakes began a slow trajectory of acidification over the remaining Holocene epoch. The natural acidification of the lakes in this region is slow, on the order of several millennia for one pH unit. Each of the study lakes exhibit relatively stable aquatic communities during the Holocene Thermal Maximum, suggesting this period is a poor analogue for modern climatic changes. During the Neoglacial, the beginning of the post-Little Ice Age period represents the most significant climatic event to impact the lakes of N. Manitoba. In the context of regional lake histories, the rate of diatom floristic change in the last 200-300 years is unprecedented, with the exception of post-glacial lake ontogeny in some of the lakes. For nearly the entire history of the lakes in this region, there is a strong linkage between landscape development and the aquatic ecosystems; however this relationship appears to become decoupled or less strong in the post-LIA period. Significant 20th century changes in the aquatic ecosystem cannot be explained wholly by changes in the terrestrial ecosystem, suggesting that future

Bedrock geologic map of the northern Alaska Peninsula area, southwestern Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Blodgett, Robert B.; Blome, Charles D.; Mohadjer, Solmaz; Preller, Cindi C.; Klimasauskas, Edward P.; Gamble, Bruce M.; Coonrad, Warren L.

2017-03-03

The northern Alaska Peninsula is a region of transition from the classic magmatic arc geology of the Alaska Peninsula to a Proterozoic and early Paleozoic carbonate platform and then to the poorly understood, tectonically complex sedimentary basins of southwestern Alaska. Physiographically, the region ranges from the high glaciated mountains of the Alaska-Aleutian Range to the coastal lowlands of Cook Inlet on the east and Bristol Bay on the southwest. The lower Ahklun Mountains and finger lakes on the west side of the map area show strong effects from glaciation. Structurally, a number of major faults cut the map area. Most important of these are the Bruin Bay Fault that parallels the coast of Cook Inlet, the Lake Clark Fault that cuts diagonally northeast to southwest across the eastern part of the map area, and the presently active Holitna Fault to the northwest that cuts surficial deposits.Distinctive rock packages assigned to three provinces are overlain by younger sedimentary rocks and intruded by widely dispersed latest Cretaceous and (or) early Tertiary granitic rocks. Much of the east half of the map area lies in the Alaska-Aleutian Range province; the Jurassic to Tertiary Alaska-Aleutian Range batholith and derivative Jurassic sedimentary rocks form the core of this province, which is intruded and overlain by the Aleutian magmatic arc. The Lime Hills province, the carbonate platform, occurs in the north-central part of the map area. The Paleozoic and Mesozoic Ahklun Mountains province in the western part of the map area includes abundant chert, argillite, and graywacke and lesser limestone, basalt, and tectonic mélange. The Kuskokwim Group, an Upper Cretaceous turbidite sequence, is extensively exposed and bounds all three provinces in the west-central part of the map area.

Holocene evolution of Lake Shkodra: Multidisciplinary evidence for diachronic landscape change in northern Albania

NASA Astrophysics Data System (ADS)

Mazzini, Ilaria; Gliozzi, Elsa; Galaty, Michael; Bejko, Lorenc; Sadori, Laura; Soulié-Märsche, Ingeborg; Koçi, Rexhep; Van Welden, Aurelien; Bushati, Salvatore

2016-03-01

A multidisciplinary micro-paleontological study of a sediment core (SK19) drilled in the coastal area of Lake Shkodra, northern Albania, integrated with archaeological data from the Projekti Arkeologjikë i Shkodrës (PASH), provides compelling evidence for a long-term relationship between Shkodra's natural environment and its inhabitants. Charophyte and ostracod data recovered from SK19 combined with those already studied from the distal core SK13 (Mazzini et al., 2015), reveal important information concerning the changing characteristics of the water body through time. In particular, the ostracod fauna display a truly Balkanic character with eight taxa endemic to the area. Palaeoenvironmental analysis of the two cores indicates that a wide marshland extended towards the present eastern coast of the lake, fed discontinuously both by surface- and ground-water, beginning sometime before 12,140 cal yrs BP. For about 7000 years ostracods do not record any significant changes, whereas the Characeae record in the proximal zone displays important variations. Those variations do not match any of the climatic oscillations revealed in previous studies by δ18O or pollen data, thereby implicating human activities. Ostracods and charophytes indicate that permanent shallow waters occurred in the Shkodra basin only around 5800 cal yrs BP. Historical sources of the Roman Empire indicate a swamp (the Palus labeatis), crossed by the River Morača, which flowed into the River Buna. Evidence for local fires, whether natural or anthropogenic, is recorded in SK13, scattered between 4400 and 1200 yrs BP. From 4400 to 2000 yrs BP, during the Bronze and Iron Age, hill forts ringed the marsh and burial mounds marked its edges. But around 2000 cal yrs BP, a dramatic change in the water body occurred: the disappearance of Characeae. Possibly fires were used for the elimination of natural vegetation and the subsequent cultivation of olive and walnut trees, causing an increase on organic

Diatoms as paleoecological indicators of environmental change in the Lake Czechowskie catchments ecosystem (Northern Tuchola Pinewoods, Poland)

NASA Astrophysics Data System (ADS)

Rzodkiewicz, Monika; Zawiska, Izabela; Noryśkiewicz, Agnieszka Maria; Obremska, Milena; Ott, Florian; Kramkowski, Mateusz; Słowiński, Michał; Błaszkiewicz, Mirosław; Brauer, Achim

2016-04-01

In this study we investigated four cores of biogenic sediments from the lakes located in close vicinity. Three cores are situated along a transect in the Lake Czechowskie basin from its deepest point towards a former lake bay. The fourth sediment core was retrieved from the nearby Trzechowskie paleolake. Lake Czechowskie is located in the northern part of the Tuchola Pinewoods District (Northern Poland) in a young glacial landscape. At present, the majority of the area is forested or used for agriculture. The main focus was of the study was Late Glacial and early Holocene period. We performed diatom, Cladocera and pollen analyses, the chronology was established by varve counting, confirmed by AMS 14C dating and Laacher See Tephra (Wulf et. all 2013). In this study we focused on the results of diatom analyses. Diatom assemblages are integrated indicators of environmental change because their distributions are closely linked to water quality parameters including such as nutrient availability. At the beginning of Allerød there are more eutrophic diatom taxa such as Staurosira construens, Pseudostaurosira brevistriata, Staurosira pinnata. These species are widely distributed in the littoral mainly freshwater, many of which are species of epiphytic, preferring water rich in nutrients. At the end of the Allerød we observe significant changes within diatom assemblages. The increase of planktonic Cyclotella comensis together with the decrease of benthic Stauroseria construens indicate the shortening of time with ice cove on the lake and longer time with summer stratification. In the Younger Dryas cooling we can see the increase of the abundance of diatom Staurosira construens which indicate cold spring and late ice-out (Bradbury et al., 2002). At the early Holocene planktonic diatoms increase in particular Cyclotella comensis, Punciculata radiosa and Cyclotella praetermissa. Some of Aulacoseira species at the end of Younger Dryas. The Holocene sediments showed no

Seismic investigation of Lake Issyk-Kul, Kyrgyzstan

NASA Astrophysics Data System (ADS)

Gebhardt, C.; Naudts, L.; De Mol, L.; De Batist, M.

2012-04-01

Lake Issyk-Kul is located in an intramontane basin of the Tien Shan mountains in Kyrgyzstan, Central Asia. It has formed in a tectonically active region with W-E striking major thrust zones north and south of the lake. The lake's modern surface level is at 1607 m above sea level, maximum depth in the central basin of the lake is roughly 670 m, and the total water volume is around 1736 km3. The lake is elongated with 180 km in west-east and 60 km in south-north direction. With a surface area of 6232 km2, Lake Issyk-Kul is the second largest lake in the higher altitudes. The lake is characterized by two large delta areas at its western and eastern end, with the deltaic area being as wide as up to 60 km in the eastern and 40 km in the western part, and by steep slopes at the northern and southern shore with only a rather narrow shallower shelf area. The lake contains the sediments of the past up to several million years, and has been proposed as a future target for deep drilling within ICDP. Three seismic surveys by Russian and Belgian groups in 1982, 1997 and 2001 revealed a thick sediment infill in Lake Issyk-Kul. At both the western and the eastern end of the lake, large delta systems were formed by actual and previous inlets, namely the Tyup and Djyrgalan rivers in the eastern part of the lake (still active) and the Chu River at the western end (currently bypassing the lake). Large sub-aquatic channel systems are visible in the lake's bathymetry in the shallower part of the delta systems close to the river mouths. They were quite likely formed by these rivers during a former lake level lowstand. The delta system consists of stacked prograding delta lobes with a characteristic topset-foreset-bottomset configuration. These lobes together with sub-aerial terraces found at several spots around the lake witness lake level fluctuations of up to >400 m. The sediments in the central plain of Lake Issyk-Kul are mainly well-layered with many turbiditic sequences

Diatom-based reconstruction of the Lake Czechowskie trophy status in the last 2000 years (Tuchola Forest, Northern Poland)

NASA Astrophysics Data System (ADS)

Rzodkiewicz, Monika; Hübener, Thomas; Ott, Florian; Kramkowski, Mateusz; Obremska, Milena; Słowiński, Michał; Zawiska, Izabela; Błaszkiewicz, Mirosław; Brauer, Achim

2015-04-01

Lakes ecosystems are very sensitive to climate and environment fluctuation. In lake sediments there are preserved remains of plant and animals that lived in the lake and its surroundings in the past. In paleolimnological research we analyse the species composition of the assemblages preserved in the sediments and on this base reconstruct past environment changes (climate changes). One of the most commonly used bio-proxy for reconstruction of lake development are subfossil diatoms. Diatoms are commonly used to reconstruct such environment parameters as: pH, nutrient status, salinity or temperature. In our study we analysed the sediments of Lake Czechowskie, which is located in the northern part of the Tuchola Forest region (Northern Poland). Lacustrine sediments of this lake are laminated and therefore are unique archive to reconstruct climate and environmental changes in Northern Polish Lowland. In this research we focused on the last 2000 years and with high resolution analyzed diatoms, pollen and sediment geochemistry. The core chronology is based varve counting, 14C AMS dating of terrestrial macro remains, 137Cs activity measurement. Diatoms communities during the last 2000 years were rich and mostly very well preserved. A characteristic feature of those communities is the dominance of typically planktonic species of the spring phytoplankton, as the oligo to mesotraphent Cyclotella comensis but also the eutraphent Stephanodiscus parvus. We also aimed at quantitative reconstruction of the pH and eutrophication(TP) using diatom-based transfer functions in order to identify reference conditions for the Lake Czechowskie. Transfer function are based on the assumption that the modern biological proxies, which ecological requirements are known, can be used to quantitative reconstructions of the past changes. This study is a contribution to the Virtual Institute ICLEA (Integrated Climate and Landscape Evolution Analysis) funded by the Helmholtz Association. The research

Integrative investigations on sediments in the Belauer See catchment (northern Germany)

NASA Astrophysics Data System (ADS)

Dreibrodt, Stefan

2015-04-01

The Holocene history of lake development, catchment vegetation, soil formation and human impact since the onset of the Neolithic period was reconstructed via the analysis of sediment sequences at Lake Belau (northern Germany). The chronology of the annually laminated lake sediment sequence was established via varve counts, radiocarbon dating and tephra analysis. Sequences of colluvial sediments and buried soils studied in 19 large exposures and supplementing auger cores within the lake catchment area were dated via radiocarbon dating and archaeological dating of embedded artifacts. The long term development of the lake status was found to be strongly influenced by local human activity. This is indicated by coincidence of phases of landscape openness deduced from pollen data with input of detritus and solutes into the lake. A comparison with palaeo-climate reconstructions reveals that calcite precipitation in the lake reflects climate variability at least to a certain degree. Calibrating the sediment record of the sub-recent lake sediments (micro-facies) on limnological and meteorological records discovered the influence of the NAO as well as solar activity on the limnological processes during the last century reflected by distinguished sedimentation patterns. A comparative study of additional laminated surface sediment sequences from northern Germany corroborates the results. A high resolution reconstruction of Neolithic weather conditions in northern Germany based on the varves of Lake Belau and Lake Poggensee was facilitated by the calibration. The quantitative records of sediments originating from soil erosion (colluvial sediments, allochthonous input into the lake) illustrate the dominance of short distance surface processes (slopes) acting in Holocene mid-latitude landscapes. Coincidence of gully incision in the lake catchment area and increased allochthonous input into the lake indicates the former occurrence of hydrological high energy runoff events (e. g

Relation of nutrient concentrations, nutrient loading, and algal production to changes in water levels in Kabetogama Lake, Voyageurs National Park, northern Minnesota, 2008-09

USGS Publications Warehouse

Christensen, Victoria G.; Maki, Ryan P.; Kiesling, Richard L.

2011-01-01

Nutrient enrichment has led to excessive algal growth in Kabetogama Lake, Voyageurs National Park, northern Minnesota. Water- and sediment-quality data were collected during 2008-09 to assess internal and external nutrient loading. Data collection was focused in Kabetogama Lake and its inflows, the area of greatest concern for eutrophication among the lakes of Voyageurs National Park. Nutrient and algal data were used to determine trophic status and were evaluated in relation to changes in Kabetogama Lake water levels following changes to dam operation starting in 2000. Analyses were used to estimate external nutrient loading at inflows and assess the potential contribution of internal phosphorus loading. Kabetogama Lake often was mixed vertically, except for a few occasionally stratified areas, including Lost Bay in the northeastern part of Kabetogama Lake. Stratification, combined with larger bottom-water nutrient concentrations, larger sediment phosphorus concentrations, and estimated phosphorus release rates from sediment cores indicate that Lost Bay may be one of several areas that may be contributing substantially to internal loading. Internal loading is a concern because nutrients may cause excessive algal growth including potentially toxic cyanobacteria. The cyanobacterial hepatotoxin, microcystin, was detected in 7 of 14 cyanobacterial bloom samples, with total concentrations exceeding 1.0 microgram per liter, the World Health Organization's guideline for finished drinking water for the congener, microcystin-LR. Comparisons of the results of this study to previous studies indicate that chlorophyll-a concentrations and trophic state indices have improved since 2000, when the rules governing dam operation changed. However, total-phosphorus concentrations have not changed significantly since 2000.

DOLUS LAKES ROADLESS AREA, MONTANA.

USGS Publications Warehouse

Elliott, James E.; Avery, Dale W.

1984-01-01

A mineral survey of the Dolus Lakes Roadless Area in southwestern Montana, was conducted. Much of the roadless area has probable and substantiated potential for resources of gold, silver, molybdenum, and tungsten. The nature of the geologic terrain indicates that there is little promise for the occurrence of coal, oil, gas, or geothermal resources. Detailed geologic and geochemical studies are suggested to delineate exploration targets that could be tested by drilling.

Uniform Temperature Dependency in the Phenology of a Keystone Herbivore in Lakes of the Northern Hemisphere

PubMed Central

Straile, Dietmar; Adrian, Rita; Schindler, Daniel E.

2012-01-01

Spring phenologies are advancing in many ecosystems associated with climate warming causing unpredictable changes in ecosystem functioning. Here we establish a phenological model for Daphnia, an aquatic keystone herbivore based on decadal data on water temperatures and the timing of Daphnia population maxima from Lake Constance, a large European lake. We tested this model with long-term time-series data from two lakes (Müggelsee, Germany; Lake Washington, USA), and with observations from a diverse set of 49 lakes/sites distributed widely across the Northern Hemisphere (NH). The model successfully captured the observed temporal variation of Daphnia phenology in the two case study sites (r2 = 0.25 and 0.39 for Müggelsee and Lake Washington, respectively) and large-scale spatial variation in the NH (R2 = 0.57). These results suggest that Daphnia phenology follows a uniform temperature dependency in NH lakes. Our approach – based on temperature phenologies – has large potential to study and predict phenologies of animal and plant populations across large latitudinal gradients in other ecosystems. PMID:23071520

Evidence for the respiration of ancient terrestrial organic C in northern temperate lakes and streams

PubMed Central

McCallister, S. Leigh; del Giorgio, Paul A.

2012-01-01

Northern rivers and lakes process large quantities of organic and inorganic carbon from the surrounding terrestrial ecosystems. These external carbon inputs fuel widespread CO2 supersaturation in continental waters, and the resulting CO2 emissions from lakes and rivers are now recognized as a globally significant loss of terrestrial production to the atmosphere. Whereas the magnitude of emissions has received much attention, the pathways of C delivery and processing that generate these emissions are still not well-understood. CO2 outgassing in aquatic systems has been unequivocally linked to microbial degradation and respiration of terrestrial organic carbon (OC), but the nature (i.e., age and source) of this OC respired in surface waters is largely unknown. We present direct radiocarbon measurements of OC respired by bacteria in freshwater aquatic systems, specifically temperate lakes and streams in Québec. Terrestrial OC fuels much of the respiration in these systems, and our results show that a significant fraction of the respired terrestrial OC is old (in the range of 1,000–3,000 y B.P.). Because the bulk OC pools in these lakes is relatively young, our results also suggest selective removal of an old but highly bioreactive terrestrial OC pool and its conversion to CO2 by bacteria. The respiration of ancient 14C-depleted terrestrial C in northern lakes and rivers provides a biological link between contemporary aquatic carbon biogeochemistry and paleo-conditions in the watershed, and it implies the aquatic-mediated return to the atmosphere of C putatively considered permanently stored, thus challenging current models of long-term C storage in terrestrial reservoirs. PMID:23027957

Ecology of playa lakes

USGS Publications Warehouse

Haukos, David A.; Smith, Loren M.

1992-01-01

Between 25,000 and 30,000 playa lakes are in the playa lakes region of the southern high plains (Fig. 1). Most playas are in west Texas (about 20,000), and fewer, in New Mexico, Oklahoma, Kansas, and Colorado. The playa lakes region is one of the most intensively cultivated areas of North America. Dominant crops range from cotton in southern areas to cereal grains in the north. Therefore, most of the native short-grass prairie is gone, replaced by crops and, recently, grasses of the Conservation Reserve Program. Playas are the predominant wetlands and major wildlife habitat of the region.More than 115 bird species, including 20 species of waterfowl, and 10 mammal species have been documented in playas. Waterfowl nest in the area, producing up to 250,000 ducklings in wetter years. Dominant breeding and nesting species are mallards and blue-winged teals. During the very protracted breeding season, birds hatch from April through August. Several million shorebirds and waterfowl migrate through the area each spring and fall. More than 400,000 sandhill cranes migrate through and winter in the region, concentrating primarily on the larger saline lakes in the southern portion of the playa lakes region.The primary importance of the playa lakes region to waterfowl is as a wintering area. Wintering waterfowl populations in the playa lakes region range from 1 to 3 million birds, depending on fall precipitation patterns that determine the number of flooded playas. The most common wintering ducks are mallards, northern pintails, green-winged teals, and American wigeons. About 500,000 Canada geese and 100,000 lesser snow geese winter in the playa lakes region, and numbers of geese have increased annually since the early 1980’s. This chapter describes the physiography and ecology of playa lakes and their attributes that benefit waterfowl.

Mapping of the total magnetic field in the area of Lake Balaton

NASA Astrophysics Data System (ADS)

Visnovitz, Ferenc; Hegyi, Betti; Raveloson, Andrea; Rozman, Gábor; Lenkey, László; Kovács, Péter; Csontos, András; Heilig, Balázs; Horváth, Ferenc

2017-04-01

The Lake Balaton with 600 km2 area represents the largest lake in Central Europe and a blank spot on the magnetic anomaly map of Hungary. It is because the construction of the Hungarian magnetic anomaly map dates back to the 1960s and relied mainly on classical vertical-field balance surveys. To fill the gap, we initiated a systematic mapping using modern magnetometers and positioning system in the framework of a complex geophysical study of Lake Balaton (National Research Project 109255 K). The main goal of this study has been to identify subvolcanic bodies and tectonic structures below the lake and correlate them with well-known features mapped onshore in the vicinity of Balaton. During the magnetic survey an Overhauser field magnetometer (GEM System, GSM-19) was mounted on a plastic boat and towed behind a motorboat in a distance of 20 m with a speed of 6 to 16 km/h depending on weather conditions. Tests measurements showed that at this distance the magnetic noise generated by the motorboat was negligible. We measured total field values with a sampling interval of 1 to 2 s. As a result, the whole lake has been covered by magnetic profiles in an orthogonal grid with spacing of 1 km. During data interpretation we applied for correction of temporal variation of magnetic field registered in the Tihany Geophysical Observatory and normal field correction from a regional model. The final anomaly map in the western part of the lake shows anomalies with amplitudes of 20 to 60 nT and a half wavelength of 0.5 to 1 km. A larger feature was recognized related to the Badacsony Hill a major basaltic bute at the northern shore of the lake. In the middle part of the lake the total field is rather smooth, no significant anomaly has been revealed. However, slight disturbances can be noticed in the proximity of a neotectonic fault zone mapped by high resolution seismic data. In the eastern part of the lake few low amplitude (5-20 nT) anomalies have been observed that are associated

Holocene phreatomagmatic eruptions alongside the densely populated northern shoreline of Lake Kivu, East African Rift: timing and hazard implications

NASA Astrophysics Data System (ADS)

Poppe, Sam; Smets, Benoît; Fontijn, Karen; Rukeza, Montfort Bagalwa; De Marie Fikiri Migabo, Antoine; Milungu, Albert Kyambikwa; Namogo, Didier Birimwiragi; Kervyn, François; Kervyn, Matthieu

2016-11-01

The Virunga Volcanic Province (VVP) represents the most active zone of volcanism in the western branch of the East African Rift System. While the VVP's two historically active volcanoes, Nyamulagira and Nyiragongo, have built scoria cones and lava flows in the adjacent lava fields, several small phreatomagmatic eruptive centers lie along Lake Kivu's northern shoreline, highlighting the potential for explosive magma-water interaction. Their presence in the densely urbanized Sake-Goma-Gisenyi area necessitates an assessment of their eruptive mechanisms and chronology. Some of these eruptive centers possess multiple vents, and depositional contacts suggest distinct eruptive phases within a single structure. Depositional facies range from polymict tuff breccia to tuff and loose lapilli, often impacted by blocks and volcanic bombs. Along with the presence of dilute pyroclastic density current (PDC) deposits, indicators of magma-water interaction include the presence of fine palagonitized ash, ash aggregates, cross-bedding, and ballistic impact sags. We estimate that at least 15 phreatomagmatic eruptions occurred in the Holocene, during which Lake Kivu rose to its current water level. Radiocarbon dates of five paleosols in the top of volcanic tuff deposits range between ˜2500 and ˜150 cal. year bp and suggest centennial- to millennial-scale recurrence of phreatomagmatic activity. A vast part of the currently urbanized zone on the northern shoreline of Lake Kivu was most likely impacted by products from phreatomagmatic activity, including PDC events, during the Late Holocene, highlighting the need to consider explosive magma-water interaction as a potential scenario in future risk assessments.

Fine-scale acoustic telemetry reveals unexpected lake trout, Salvelinus namaycush, spawning habitats in northern Lake Huron, North America

USGS Publications Warehouse

Binder, Thomas; Farha, Steve A.; Thompson, Henry T.; Holbrook, Christopher; Bergstedt, Roger A.; Riley, Stephen; Bronte, Charles R.; He, Ji; Krueger, Charles C.

2018-01-01

Previous studies of lake trout, Salvelinus namaycush, spawning habitat in the Laurentian Great Lakes have used time- and labour-intensive survey methods and have focused on areas with historic observations of spawning aggregations and on habitats prejudged by researchers to be suitable for spawning. As an alternative, we used fine-scale acoustic telemetry to locate, describe and compare lake trout spawning habitats. Adult lake trout were implanted with acoustic transmitters and tracked during five consecutive spawning seasons in a 19–27 km2 region of the Drummond Island Refuge, Lake Huron, using the VEMCO Positioning System. Acoustic telemetry revealed discrete areas of aggregation on at least five reefs in the study area, subsequently confirmed by divers to contain deposited eggs. Notably, several identified spawning sites would likely not have been discovered using traditional methods because either they were too small and obscure to stand out on a bathymetric map or because they did not conform to the conceptual model of spawning habitat held by many biologists. Our most unique observation was egg deposition in gravel and rubble substrates located at the base of and beneath overhanging edges of large boulders. Spawning sites typically comprised <10% of the reef area and were used consistently over the 5-year study. Evaluation of habitat selection from the perspective of fish behaviour through use of acoustic transmitters offers potential to expand current conceptual models of critical spawning habitat.

Bathymetric map and area/capacity table for Castle Lake, Washington

USGS Publications Warehouse

Mosbrucker, Adam R.; Spicer, Kurt R.

2017-11-14

The May 18, 1980, eruption of Mount St. Helens produced a 2.5-cubic-kilometer debris avalanche that dammed South Fork Castle Creek, causing Castle Lake to form behind a 20-meter-tall blockage. Risk of a catastrophic breach of the newly impounded lake led to outlet channel stabilization work, aggressive monitoring programs, mapping efforts, and blockage stability studies. Despite relatively large uncertainty, early mapping efforts adequately supported several lake breakout models, but have limited applicability to current lake monitoring and hazard assessment. Here, we present the results of a bathymetric survey conducted in August 2012 with the purpose of (1) verifying previous volume estimates, (2) computing an area/capacity table, and (3) producing a bathymetric map. Our survey found seasonal lake volume ranges between 21.0 and 22.6 million cubic meters with a fundamental vertical accuracy representing 0.88 million cubic meters. Lake surface area ranges between 1.13 and 1.16 square kilometers. Relationships developed by our results allow the computation of lake volume from near real-time lake elevation measurements or from remotely sensed imagery.

Population status and population genetics of northern leopard frogs in Arizona

USGS Publications Warehouse

Theimer, Tad C.; Drost, Charles A.; O'Donnell, Ryan P.; Mock, Karen E.

2011-01-01

Increasing isolation of populations by habitat fragmentation threatens the persistence of many species, both from stochastic loss of small isolated populations, and from inbreeding effects in populations that have become genetically isolated. In the southwestern United States, amphibian habitat is naturally patchy in occurrence because of the prevailing aridity of the region. Streams, rivers, and other wetlands are important both as habitat and as corridors that connect populations. However, populations of some species have become more fragmented and isolated by habitat degradation and loss. Northern leopard frogs (Rana pipiens) have experienced serious declines in the Southwest. We conducted an extensive survey across the known range of northern leopard frogs in Arizona to determine the current distribution and abundance of the species. From a range that once spanned much of the northern and central part of the State, northern leopard frogs have been reduced to three or four widely separated populations, near Lyman Lake in east-central Arizona, in the Stoneman Lake area south of Flagstaff, along Truxton Wash near Peach Springs, and a population of uncertain extent on Navajo Nation lands. The Lyman Lake and Truxton Wash populations are small and extremely isolated. The Stoneman Lake population, however, is an extensive metapopulation spread across several stream drainages, including numerous ponds, wetlands, and artificial tanks. This is the only population in Arizona that is increasing in extent and numbers, but there is concern about the apparent introduction of nonnative genetic stock from eastern North America into this area. We analyzed genetic diversity within and genetic divergence among populations of northern leopard frogs, across both extant and recently extirpated populations in Arizona. We also analyzed mitochondrial DNA to place these populations into a larger phylogenetic framework and to determine whether any populations contained genetic material

Deglaciation, lake levels, and meltwater discharge in the Lake Michigan basin

USGS Publications Warehouse

Colman, Steven M.; Clark, J.A.; Clayton, L.; Hansel, A.K.; Larsen, C.E.

1994-01-01

The deglacial history of the Lake Michigan basin, including discharge and routing of meltwater, is complex because of the interaction among (1) glacial retreats and re-advances in the basin (2) the timing of occupation and the isostatic adjustment of lake outlets and (3) the depositional and erosional processes that left evidence of past lake levels. In the southern part of the basin, a restricted area little affected by differential isostasy, new studies of onshore and offshore areas allow refinement of a lake-level history that has evolved over 100 years. Important new data include the recognition of two periods of influx of meltwater from Lake Agassiz into the basin and details of the highstands gleaned from sedimentological evidence. Major disagreements still persist concerning the exact timing and lake-level changes associated with the Algonquin phase, approximately 11,000 BP. A wide variety of independent data suggests that the Lake Michigan Lobe was thin, unstable, and subject to rapid advances and retreats. Consequently, lake-level changes were commonly abrupt and stable shorelines were short-lived. The long-held beliefs that the southern part of the basin was stable and separated from deformed northern areas by a hinge-line discontinuity are becoming difficult to maintain. Numerical modeling of the ice-earth system and empirical modeling of shoreline deformation are both consistent with observed shoreline tilting in the north and with the amount and pattern of modern deformation shown by lake-level gauges. New studies of subaerial lacustrine features suggest the presence of deformed shorelines higher than those originally ascribed to the supposed horizontal Glenwood level. Finally, the Lake Michigan region as a whole appears to behave in a similar manner to other areas, both local (other Great Lakes) and regional (U.S. east coast), that have experienced major isostatic changes. Detailed sedimentological and dating studies of field sites and additional

78 FR 63868 - Amendment of Restricted Area R-2515; Muroc Lake, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-25

...-0802; Airspace Docket No. 13-AWP-7] RIN 2120-AA66 Amendment of Restricted Area R-2515; Muroc Lake, CA... using agency name for Restricted Area R-2515 Muroc Lake, CA, to read ``Commander, 412th Test Wing (412... using agency name for Restricted Area R-2515 Muroc Lake, CA, from ``Commander Air Force Flight Test...

ERTS-1 views the Great Lakes

NASA Technical Reports Server (NTRS)

Lyons, W. A.; Pease, S. R.

1973-01-01

The meteorological content of ERTS images, particularly mesoscale effects of the Great Lakes and air pollution dispersion is summarized. Summertime lake breeze frontal clouds and various winter lake-effect convection patterns and snow squalls are revealed in great detail. A clear-cut spiral vortex over southern Lake Michigan is related to a record early snow storm in the Chicago area. Marked cloud changes induced by orographic and frictional effects on Lake Michigan's lee shore snow squalls are seen. The most important finding, however, is a clear-cut example of alterations in cumulus convection by anthropogenic condensation and/or ice nuclei from northern Indiana steel mills during a snow squall situation. Jet aircraft condensation trails are also found with surprising frequency.

THE WESTERN LAKE SUPERIOR COMPARATIVE WATERSHED FRAMEWORK: A FIELD TEST OF GEOGRAPHICALLY-DEPENDENT VS. THRESHOLD-BASED GEOGRAPHICALLY-INDEPENDENT CLASSIFICATION

EPA Science Inventory

Stratified random selection of watersheds allowed us to compare geographically-independent classification schemes based on watershed storage (wetland + lake area/watershed area) and forest fragmentation with a geographically-based classification scheme within the Northern Lakes a...

View of the Salt Lake City, Utah area

NASA Image and Video Library

1973-08-30

SL3-22-0322 (July-September 1973) --- An oblique view of the Salt Lake City, Utah area as photographed from Earth orbit by one of the six lenses of the Itek-furnished S190-A Multispectral Photographic Facility Experiment aboard the Skylab space station. Approximately two-thirds of the Great Salt Lake is in view. The smaller body of water south of Salt Lake City is Utah Lake. The Wasatch Range is on the east side of the Great Salt Lake. Federal agencies participating with NASA on the EREP project are the Departments of Agriculture, Commerce, Interior, the Environmental Protection Agency and the Corps of Engineers. All EREP photography is available to the public through the Department of Interior?s Earth Resources Observations Systems Data Center, Sioux Falls, South Dakota, 57198. Photo credit: NASA

Late Pleistocene Hansel Valley basaltic ash, northern Lake Bonneville, Utah, USA

USGS Publications Warehouse

Miller, D.M.; Oviatt, Charles G.; Nash, B.P.

2008-01-01

The Hansel Valley ash bed lies within 5 cm of the base of deposits of Lake Bonneville (???28 ka) in the vicinity of Great Salt Lake and provides a useful stratigraphic marker for this area of the lake basin. However, it has not been matched to an eruptive edifice, presumably because such an edifice was eroded by waves of Lake Bonneville. We present data for the chemical composition of the tephra and for possible matching lavas and tephras of the region, as well as grain size data for the tephra in an attempt to identify the location of the eruption. Matches with other tephras are negative, but lavas near the coarsest ash deposits match well with the distinctive high values of TiO2 and P2O5 of the ash. Neither chemistry nor grain size data points uniquely to a source area, but an area near the northwest shore of Great Salt Lake and within Curlew Valley is most likely. The Hansel Valley ash is an example of an ash that has no direct numerical date from proximal deposits, despite considerable study, yet nonetheless is useful for stratigraphic studies by virtue of its known stratigraphic position and approximate age. Basaltic tephras commonly are not as widespread as their rhyolitic counterparts, and in some cases apparently are produced by eruptive sources that are short lived and whose edifices are not persistent. ?? 2007 Elsevier Ltd and INQUA.

Roger Lake research natural area: guidebook supplement 29.

Treesearch

J. Dana Visalli

2006-01-01

Roger Lake Research Natural Area (RNA), a 174.7-ha reserve in north-central Washington, contains a rich diversity of landforms, plant communities, and wildlife habitats. Spreading outward from the lake itself, sedge and sphagnum fens give way to upland coniferous forest, granitic cliffs, and a relictual, high-altitude big sagebrush-whitebark pine (Artemisia tridentata-...

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

Cassini RADAR observations of lakes and seas in the Northern Polar region of Titan: Bathymetry and Composition

NASA Astrophysics Data System (ADS)

Mastrogiuseppe, Marco; Hayes, Alex; Poggiali, Valerio; Lunine, Jonathan; Seu, Roberto; Hofgartner, Jason; Le Gall, Alice; Lorenz, Ralph; Mitri, Giuseppe

2017-04-01

Recent observations by the Cassini spacecraft has revealed its RADAR to be an invaluable tool for investigating Titan's seas and lakes. The T91 (May 2013) observation of Ligeia Mare, Titan's second largest sea, has demonstrated the capabilities of the RADAR, in its altimeter mode, to measure depth, composition and seafloor topography. The 104 (August 2014) observation provided similar data over the largest sea, Kraken Mare, and the T108 (January 2015) flyby acquired an altimetry pass over Punga Mare. The T49 (December 2007) altimetry pass over Ontario Lacus, the largest southern liquid body, has also been processed to retrieve subsurface echoes. Cassini's final flyby of Titan, T126 (April 2017), is the next and unique opportunity to observe an area in the Northern Polar region of Titan, where several small - medium size (5 - 30 km) lakes are present and have been previously imaged by Cassini. In our presentation, we will report the integrated results of these investigations and discuss them in the overall context of Titan's hydrologic cycle.

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

High mountain lake Research Natural Areas in Idaho

Treesearch

Fred W. Rabe

2001-01-01

High mountain lakes in Idaho total about 1800 and represent one of the most pristine type ecosystems in the country. Limnological characteristics are described for 27 lakes and 20 ponds in 32 established and proposed Research Natural Areas (RNA) representing seven subregions in the state. Field collections were made from the 1960s through 1999 by different researchers...

Chemical evolution of groundwater near a sinkhole lake, northern Florida: 1. Flow patterns, age of groundwater, and influence of lakewater leakage

USGS Publications Warehouse

Katz, Brian G.; Lee, Terrie M.; Plummer, Niel; Busenberg, Eurybiades

1995-01-01

Leakage from sinkhole lakes significantly influences recharge to the Upper Floridan aquifer in poorly confined sediments in northern Florida. Environmental isotopes (oxygen 18, deuterium, and tritium), chlorofluorocarbons (CFCs: CFC-11, CCl3F; CFC-12, CCl2F2; and CFC-113, C2Cl3F3), and solute tracers were used to investigate groundwater flow patterns near Lake Barco, a seepage lake in a mantled karst setting in northern Florida. Stable isotope data indicated that the groundwater downgradient from the lake contained 11–67% lake water leakage, with a limit of detection of lake water in groundwater of 4.3%. The mixing fractions of lake water leakage, which passed through organic-rich sediments in the lake bottom, were directly proportional to the observed methane concentrations and increased with depth in the groundwater flow system. In aerobic groundwater upgradient from Lake Barco, CFC-modeled recharge dates ranged from 1987 near the water table to the mid 1970s for water collected at a depth of 30 m below the water table. CFC-modeled recharge dates (based on CFC-12) for anaerobic groundwater downgradient from the lake ranged from the late 1950s to the mid 1970s and were consistent with tritium data. CFC-modeled recharge dates based on CFC-11 indicated preferential microbial degradation in anoxic waters. Vertical hydraulic conductivities, calculated using CFC-12 modeled recharge dates and Darcy's law, were 0.17, 0.033, and 0.019 m/d for the surficial aquifer, intermediate confining unit, and lake sediments, respectively. These conductivities agreed closely with those used in the calibration of a three-dimensional groundwater flow model for transient and steady state flow conditions.

Environmental Statement, Lake City Station, Unit One.

DTIC Science & Technology

1973-09-17

quality, ecological effects, energy demand, entrainment, environmental effects, fish and wildlife values, Lake Erie, pollution control, social and...Creek on the northern part of the site. That portion of the site, adjacent to Lake Erie and Elk Creek, is wooded with the remaining portions being...loam to loanm, fine sand (Reference 2-1). 2-1 - - i Approximately 60 percent of the area is covered with mixed hard woods and conifers, however, the

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 Havasu...

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 Havasu...

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....; naval bombing area. (a) The danger zone. An area in the eastern part of Lake George described as follows.... (2) Prior to each bombing operation the danger zone will be patrolled by naval aircraft which will...

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....; naval bombing area. (a) The danger zone. An area in the eastern part of Lake George described as follows.... (2) Prior to each bombing operation the danger zone will be patrolled by naval aircraft which will...

Factors Controlling Methane in Arctic Lakes of Southwest Greenland

PubMed Central

2016-01-01

We surveyed 15 lakes during the growing season of 2014 in Arctic lakes of southwest Greenland to determine which factors influence methane concentrations in these systems. Methane averaged 2.5 μmol L-1 in lakes, but varied a great deal across the landscape with lakes on older landscapes farther from the ice sheet margin having some of the highest values of methane reported in lakes in the northern hemisphere (125 μmol L-1). The most important factors influencing methane in Greenland lakes included ionic composition (SO4, Na, Cl) and chlorophyll a in the water column. DOC concentrations were also related to methane, but the short length of the study likely underestimated the influence and timing of DOC on methane concentrations in the region. Atmospheric methane concentrations are increasing globally, with freshwater ecosystems in northern latitudes continuing to serve as potentially large sources in the future. Much less is known about how freshwater lakes in Greenland fit in the global methane budget compared to other, more well-studied areas of the Arctic, hence our work provides essential data for a more complete view of this rapidly changing region. PMID:27454863

Factors Controlling Methane in Arctic Lakes of Southwest Greenland.

PubMed

Northington, Robert M; Saros, Jasmine E

2016-01-01

We surveyed 15 lakes during the growing season of 2014 in Arctic lakes of southwest Greenland to determine which factors influence methane concentrations in these systems. Methane averaged 2.5 μmol L-1 in lakes, but varied a great deal across the landscape with lakes on older landscapes farther from the ice sheet margin having some of the highest values of methane reported in lakes in the northern hemisphere (125 μmol L-1). The most important factors influencing methane in Greenland lakes included ionic composition (SO4, Na, Cl) and chlorophyll a in the water column. DOC concentrations were also related to methane, but the short length of the study likely underestimated the influence and timing of DOC on methane concentrations in the region. Atmospheric methane concentrations are increasing globally, with freshwater ecosystems in northern latitudes continuing to serve as potentially large sources in the future. Much less is known about how freshwater lakes in Greenland fit in the global methane budget compared to other, more well-studied areas of the Arctic, hence our work provides essential data for a more complete view of this rapidly changing region.

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.

77 FR 49712 - Amendment to Class B Airspace; Salt Lake City, UT

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-17

... operating in the vicinity of SLC. The modified Class B airspace areas were designed to ensure all instrument... final Salt Lake City Class B airspace design provides operational and safety benefits to all airspace... Salt Lake City Class B airspace design also incorporated reductions to the northern and southern...

Quantifying the impact of bathymetric changes on the hydrological regimes in a large floodplain lake: Poyang Lake

NASA Astrophysics Data System (ADS)

Yao, Jing; Zhang, Qi; Ye, Xuchun; Zhang, Dan; Bai, Peng

2018-06-01

The hydrological regime of a lake is largely dependent on its bathymetry. A dramatic water level reduction has occurred in Poyang Lake in recent years, coinciding with significant bed erosion. Few studies have focused on the influence of bathymetric changes on the hydrological regime in such a complex river-lake floodplain system. This study combined hydrological data and a physically based hydrodynamic model to quantify the influence of the bathymetric changes (1998-2010) on the water level spatiotemporal distribution in Poyang Lake, based on a dry year (2006), a wet year (2010) and an average year (2000-2010). The following conclusions can be drawn from the results of this study: (1) The bed erosion of the northern outlet channel averaged 3 m, resulting in a decrease in the water level by 1.2-2 m in the northern channels (the most significantly influenced areas) and approximately 0.3 m in the central lake areas during low-level periods. The water levels below 16 m and 14 m were significantly affected during the rising period and recession period, respectively. The water level reduction was enhanced due to lower water levels. (2) The water surface profiles adjusted, and the rising and recession rates of the water level increased by 0.5-3.1 cm/d at the lake outlet. The bathymetric influence extended across the entire lake due to the emptying effect, resulting in a change in the water level distribution. The average annual outflow increased by 6.8%. (3) The bathymetric changes contributed approximately 14.4% to the extreme low water level in autumn 2006 and enhanced the drought in the dry season. This study quantified the impact of the bathymetric changes on the lake water levels, thereby providing a better understanding of the potential effects of continued sand mining operations and providing scientific explanations for the considerable variations in the hydrological regimes of Poyang Lake. Moreover, this study attempts to provide a reference for the assessment of

A preliminary report on the growth of the rock bass, Ambloplites rupestris (Rafinesque), in two lakes of northern Wisconsin

USGS Publications Warehouse

Wright, Stillman

1929-01-01

For several years the Wisconsin Geological and Natural History Survey has been making a limnological study of lakes in the northern part of the State. Because of the fact that so much has been learned of the physical, chemical and biological conditions in these lakes, the region seems particularly favorable for a study of the growth rates of fishes in relation to environmental factors.

The impact of climate and environmental processes on vegetation pattern in the Czechowskie lake catchment Czechowo Region (Northern Tuchola Pinewoods) during the Younger Dryas cooling

NASA Astrophysics Data System (ADS)

Noryśkiewicz, Agnieszka Maria; Kramkowski, Mateusz; Słowiński, Michał; Zawiska, Izabela; Lutyńska, Monika; Błaszkiewicz, Mirosław; Brauer, Achim

2014-05-01

Czechowskie lake is located in the northern part of the Tuchola Pinewoods District (Northern Poland) in a young glacial landscape. At present, the majority of the area is forested or used for agricultural purposes, but among them a high amount of basins filled with biogenic sediments are present. This area is very suitable for the postglacial vegetation development investigation because of the LST ash and laminated sediments which we found in the Trzechowskie palaeolake and Czechowskie Lake (Wulf et. all 2013). The aim of the research was to reconstruct the past landscape and vegetation response to Younger Dryas cooling and we present the results of the palinological analysis done for 6 core of biogenic sediments. Our main objective was to determine whether local factors such as topography and soil cover have a significant impact on the vegetation, eutrophy and sedimentation rate at this time. In the lake Czechowskie lake catchment we have six cores that cover postglacial succession (Lake Czechowskie small basin - profile JC-12-s; Lake Czechowskiego terrace - profile TK; Lake Czechowskie vicinity - profile "Oko and Cz/80; Trzechowskie paleolake - profile T/trz; Valley between paleolake Trzechowskie and Lake Czechowskie - profile DTCZ-4). The paleoecological research carried out involved an analysis of pollen, macrofossils, Cladocera, diatom, loss-on-ignition and CaCO3 content. The results show, that the dominant plant communities during the Youngers Dryas in the region nearby Lake Czechowskie are heliophytes xeric herb vegetation with juniper (Juniperus communis) shrubs and birch (Betula) and pine (Pinus sylvestris). In the pollen diagrams there was the difference noted in the participation of the dominant pollen, the juniper pollen was always high but varied from 18 to 37%, birch average pollen share was between 17-27%. The thickness and type of the sediment accumulated in Younger Dryas in the presented profiles differs significantly. In the profiles which

Lake-sediment evidence for the date of deglaciation of the Hidden Lake area, Kenai Peninsula, Alaska

NASA Astrophysics Data System (ADS)

Rymer, Michael J.; Sims, John D.

1982-06-01

An abrupt environmental change is reflected in a core from Hidden Lake, Alaska, by differences in sediment type, chlorite crystallinity, and content of organic carbon and water of the sediments. This abrupt change in the sedimentary record occurred about 14,500 14C yr ago and probably marks the time of recession of the glacier from the Hidden Lake drainage basin. Deglaciation of the area was then underway, and rock flour was being deposited in the lake. After recession of the glacier from the Hidden Lake drainage basin, rock flour was no longer introduced, and organic-matter content of the sediment increased. By the dating of these changes in sediment type, we show that retreat of glaciers in this area took place significantly earlier than previously estimated; this agrees with the timing of retreat of alpine glaciers elsewhere in western North America.

Periodic jökulhlaups from Pleistocene glacial Lake Missoula-New evidence from varved sediment in northern Idaho and Washington

USGS Publications Warehouse

Waitt, Richard B.

1984-01-01

Newly examined exposures in northern Idaho and Washington show that catastrophic floods from glacial Lake Missoula during late Wisconsin time were repeated, brief jökulhlaups separated by decades of quiet glaciolacustrine and subaerial conditions. Glacial Priest Lake, dammed in the Priest River valley by a tongue of the Purcell trench lobe of the Cordilleran ice sheet, generally accumulated varved mud; the varved mud is sharply interrupted by 14 sand beds deposited by upvalley-running currents. The sand beds are texturally and structurally similar to slackwater sediment in valleys in southern Washington that were backflooded by outbursts from glacial Lake Missoula. Beds of varved mud also accumulated in glacial Lake Spokane (or Columbia?) in Latah Creek valley and elsewhere in northeastern Washington; the mud beds were disrupted, in places violently, during emplacement of each of 16 or more thick flood-gravel beds. This history corroborates evidence from southern Washington that only one graded bed is deposited per flood, refuting a conventional idea that many beds accumulated per flood. The total number of such floodlaid beds in stratigraphic succession near Spokane is at least 28. The mud beds between most of the floodlaid beds in these valleys each consist of between 20 and 55 silt-to-clay varves. Lacustrine environments in northern Idaho and Washington therefore persisted for two to six decades between regularly recurring, colossal floods from glacial Lake Missoula.

Schlumberger soundings near Medicine Lake, California

USGS Publications Warehouse

Zohdy, A.A.R.; Bisdorf, R.J.

1990-01-01

The use of direct current resistivity soundings to explore the geothermal potential of the Medicine Lake area in northern California proved to be challenging because of high contact resistances and winding roads. Deep Schlumberger soundings were made by expanding current electrode spacings along the winding roads. Corrected sounding data were interpreted using an automatic interpretation method. Forty-two maps of interpreted resistivity were calculated for depths extending from 20 to 1000 m. Computer animation of these 42 maps revealed that: 1) certain subtle anomalies migrate laterallly with depth and can be traced to their origin, 2) an extensive volume of low-resistivity material underlies the survey area, and 3) the three areas (east of Bullseye Lake, southwest of Glass Mountain, and northwest of Medicine Lake) may be favorable geothermal targets. Six interpreted resistivity maps and three cross-sections illustrate the above findings. -from Authors

65. VIEW OF EAST LORING LAKE LOOKING NORTHWEST FROM DAM ...

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

65. VIEW OF EAST LORING LAKE LOOKING NORTHWEST FROM DAM NEAR BUILDING 361 (MUNITIONS MAINTENANCE SQUADRON ADMINISTRATION BUILDING) IN BASE SPARES AREA. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

Environmental changes and the Migration Period in northern Germany as reflected in the sediments of Lake Dudinghausen

NASA Astrophysics Data System (ADS)

Dreßler, Mirko; Selig, Uwe; Dörfler, Walter; Adler, Sven; Schubert, Hendrik; Hübener, Thomas

2006-07-01

Paleolimnological techniques were used to identify environmental changes in and around Lake Dudinghausen (northern Germany) over the past 4800 yr. Diatom-inferred total phosphorus (DI-TP) changes identify four phases of high nutrient levels (2600-2200 BC, 1050-700 BC, 500 BC-AD 100 and AD 1850-1970). During these high DI-TP phases, fossil pollen, sediment geochemistry and archaeological records indicate human activities in the lake catchment. Although the same paleo-indicators suggest increased human settlement and agriculture activity during the late Slavonic Age, the Medieval Time and the Modern Time (AD 1000-1850), DI-TP levels were low during this period. In the sediments, iron and total phosphorus were high from ˜AD 100 to 1850, likely due to increased inflow of iron-rich groundwater into the lake. Increased iron input would have lead to a simultaneous binding and precipitation of phosphate in the upper sediment and overlying water column. As a result, anthropogenic impact on Lake Dudinghausen was masked by these phosphorus-controlling processes from AD 1000 to 1850 and was not evident by means of DI-TP. In accordance with fossil pollen, sediment geochemistry and limited archaeological records, DI-TP levels were low from AD 100-1000. Groundwater levels likely rose during this period as the climate gradually changed toward colder and/or moister conditions. Such climate change likely led to reduced settlement activities and forest regeneration in the catchment area. Our results are concordant with similar studies from central Europe which indicate rapid decreasing settlement activities from AD 100 to 1000.

Peat accumulation in drained thermokarst lake basins in continuous, ice-rich permafrost, northern Seward Peninsula, Alaska

USGS Publications Warehouse

Jones, Miriam C.; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey Walter

2012-01-01

Thermokarst lakes and peat-accumulating drained lake basins cover a substantial portion of Arctic lowland landscapes, yet the role of thermokarst lake drainage and ensuing peat formation in landscape-scale carbon (C) budgets remains understudied. Here we use measurements of terrestrial peat thickness, bulk density, organic matter content, and basal radiocarbon age from permafrost cores, soil pits, and exposures in vegetated, drained lake basins to characterize regional lake drainage chronology, C accumulation rates, and the role of thermokarst-lake cycling in carbon dynamics throughout the Holocene on the northern Seward Peninsula, Alaska. Most detectable lake drainage events occurred within the last 4,000 years with the highest drainage frequency during the medieval climate anomaly. Peat accumulation rates were highest in young (50–500 years) drained lake basins (35.2 g C m−2 yr−1) and decreased exponentially with time since drainage to 9 g C m−2 yr−1 in the oldest basins. Spatial analyses of terrestrial peat depth, basal peat radiocarbon ages, basin geomorphology, and satellite-derived land surface properties (Normalized Difference Vegetation Index (NDVI); Minimum Noise Fraction (MNF)) from Landsat satellite data revealed significant relationships between peat thickness and mean basin NDVI or MNF. By upscaling observed relationships, we infer that drained thermokarst lake basins, covering 391 km2 (76%) of the 515 km2 study region, store 6.4–6.6 Tg organic C in drained lake basin terrestrial peat. Peat accumulation in drained lake basins likely serves to offset greenhouse gas release from thermokarst-impacted landscapes and should be incorporated in landscape-scale C budgets.

New age constraints for the Saalian glaciation in northern central Europe: Implications for the extent of ice sheets and related proglacial lake systems

NASA Astrophysics Data System (ADS)

Lang, Jörg; Lauer, Tobias; Winsemann, Jutta

2018-01-01

A comprehensive palaeogeographic reconstruction of ice sheets and related proglacial lake systems for the older Saalian glaciation in northern central Europe is presented, which is based on the integration of palaeo-ice flow data, till provenance, facies analysis, geomorphology and new luminescence ages of ice-marginal deposits. Three major ice advances with different ice-advance directions and source areas are indicated by palaeo-ice flow directions and till provenance. The first ice advance was characterised by a southwards directed ice flow and a dominance of clasts derived from southern Sweden. The second ice advance was initially characterised by an ice flow towards the southwest. Clasts are mainly derived from southern and central Sweden. The latest stage in the study area (third ice advance) was characterised by ice streaming (Hondsrug ice stream) in the west and a re-advance in the east. Clasts of this stage are mainly derived from eastern Fennoscandia. Numerical ages for the first ice advance are sparse, but may indicate a correlation with MIS 8 or early MIS 6. New pIRIR290 luminescence ages of ice-marginal deposits attributed to the second ice advance range from 175 ± 10 to 156 ± 24 ka and correlate with MIS 6. The ice sheets repeatedly blocked the main river-drainage pathways and led to the formation of extensive ice-dammed lakes. The formation of proglacial lakes was mainly controlled by ice-damming of river valleys and major bedrock spillways; therefore the lake levels and extends were very similar throughout the repeated ice advances. During deglaciation the lakes commonly increased in size and eventually drained successively towards the west and northwest into the Lower Rhine Embayment and the North Sea. Catastrophic lake-drainage events occurred when large overspill channels were suddenly opened. Ice-streaming at the end of the older Saalian glaciation was probably triggered by major lake-drainage events.

64. VIEW OF EAST LORING LAKE LOOKING WEST FROM HILL ...

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

64. VIEW OF EAST LORING LAKE LOOKING WEST FROM HILL BEHIND BUILDING 345 (ENTRY CONTROL BUILDING) IN STORAGE AREA, WITH BUILDING 1026 (BASE SPARES AREA WATER TOWER) IN DISTANCE. - Loring Air Force Base, Weapons Storage Area, Northeastern corner of base at northern end of Maine Road, Limestone, Aroostook County, ME

Limnology of Botos Lake, a tropical crater lake in Costa Rica.

PubMed

Umaña, G

2001-12-01

Botos Lake, located at the Poas Volcano complex (Costa Rica) was sampled eight times from 1994 to 1996 for physicochemical conditions of the water column and phytoplanktonic community composition. Depth was measured at fixed intervals in several transects across the lake to determine its main morphometric characteristics. The lake has an outlet to the north. It is located 2580 m above sea level and is shallow, with a mean depth of 1.8 m and a relative depth of 2.42 (surface area 10.33 ha, estimated volume 47.3 hm3). The lake showed an isothermal water column in all occasions, but it heats and cools completely according to weather fluctuations. Water transparency reached the bottom on most occasions (> 9 m). The results support the idea that the lake is polymictic and oligotrophic. The lake has at least 23 species of planktonic algae, but it was always dominated by dinoflagellates, especially Peridinium inconspicuum. The shore line is populated by a sparse population of Isoetes sp. and Eleocharis sp. mainly in the northern shore where the bottom has a gentle slope and the forest does not reach the shore.

Hydrologic Modeling of Relatively Recent Martian Streams and Lake

NASA Image and Video Library

2016-09-15

This map of an area within the Arabia Terra region on Mars shows where hydrologic modeling predicts locations of depressions that would have been lakes (black), overlaid with a map of the preserved valleys (blue lines, with width exaggerated for recognition) that would have been streams. The area today holds numerous features called "fresh shallow valleys." Research findings in 2016 interpret the fresh shallow valleys as evidence for flows of liquid water that occurred several hundred million years -- up to about a billion years -- after the ancient lakes and streams previously documented on Mars. Most of the fresh shallow valleys in this northern portion of Arabia Terra terminate at the margins of model-predicted submerged basins, consistent with an interpretation of flows into lakes and out of lakes. Some valley segments connect to form longer systems, consistent with connections forged by flowing water between interspersed lakes. In the area mapped here, for example, valleys connect basin "A" to basin "B," and basin B to "Heart Lake," each lower in elevation in that chain. http://photojournal.jpl.nasa.gov/catalog/PIA20839

Glacial and Quaternary geology of the northern Yellowstone area, Montana and Wyoming

USGS Publications Warehouse

Pierce, Kenneth L.; Licciardi, Joseph M.; Krause, Teresa R.; Whitlock, Cathy

2014-01-01

This field guide focuses on the glacial geology and paleoecology beginning in the Paradise Valley and progressing southward into northern Yellowstone National Park. During the last (Pinedale) glaciation, the northern Yellowstone outlet glacier flowed out of Yellowstone Park and down the Yellowstone River Valley into the Paradise Valley. The field trip will traverse the following Pinedale glacial sequence: (1) deposition of the Eightmile terminal moraines and outwash 16.5 ± 1.4 10Be ka in the Paradise Valley; (2) glacial recession of ~8 km and deposition of the Chico moraines and outwash 16.1 ± 1.7 10Be ka; (3) glacial recession of 45 km to near the northern Yellowstone boundary and moraine deposition during the Deckard Flats readjustment 14.2 ± 1.2 10Be ka; and (4) glacial recession of ~37 km and deposition of the Junction Butte moraines 15.2 ± 1.3 10Be ka (this age is a little too old based on the stratigraphic sequence). Yellowstone's northern range of sagebrush-grasslands and bison, elk, wolf, and bear inhabitants is founded on glacial moraines, sub-glacial till, and outwash deposited during the last glaciation. Floods released from glacially dammed lakes and a landslide-dammed lake punctuate this record. The glacial geologic reconstruction was evaluated by calculation of basal shear stress, and yielded the following values for flow pattern in plan view: strongly converging—1.21 ± 0.12 bars (n = 15); nearly uniform—1.04 ± 0.16 bars (n = 11); and strongly diverging—0.84 ± 0.14 bars (n = 16). Reconstructed mass balance yielded accumulation and ablation each of ~3 km3/yr, with glacial movement near the equilibrium line altitude dominated by basal sliding. Pollen and charcoal records from three lakes in northern Yellowstone provide information on the postglacial vegetation and fire history. Following glacial retreat, sparsely vegetated landscapes were colonized first by spruce parkland and then by closed subalpine forests. Regional fire activity

Lake Shasta, California

NASA Image and Video Library

2015-06-17

This image from NASA Terra spacecraft shows Shasta Lake in northern California, which has an area of 12,000 ha, making it the state largest reservoir. Impacts of the continuing drought in the western US is evident in the two ASTER images acquired 9 years apart. The images were acquired September 9, 2005 and September 2, 2014. They cover an area of 27.6 x 40.4 km, and are located at 40.6 degrees north, 122.4 degrees west. http://photojournal.jpl.nasa.gov/catalog/PIA19492

Lake states management differs from northeast

Treesearch

Richard M. Godman

1992-01-01

There are "northern hardwoods" in the Lake States and "northern hardwoods" in the Northeast. The term is the same but the forest cover types, stand, and site conditions can be very different. The silvicultural treatments that work in the Northeast may not work at all in the Lake States. And what works in the Lake States will work - but not the best...

Recent lake ice-out phenology within and among lake districts of Alaska, U.S.A.

USGS Publications Warehouse

Arp, Christopher D.; Jones, Benjamin M.; Grosse, Guido

2013-01-01

The timing of ice-out in high latitudes is a fundamental threshold for lake ecosystems and an indicator of climate change. In lake-rich regions, the loss of ice cover also plays a key role in landscape and climatic processes. Thus, there is a need to understand lake ice phenology at multiple scales. In this study, we observed ice-out timing on 55 large lakes in 11 lake districts across Alaska from 2007 to 2012 using satellite imagery. Sensor networks in two lake districts validated satellite observations and provided comparison with smaller lakes. Over this 6 yr period, the mean lake ice-out for all lakes was 27 May and ranged from 07 May in Kenai to 06 July in Arctic Coastal Plain lake districts with relatively low inter-annual variability. Approximately 80% of the variation in ice-out timing was explained by the date of 0°C air temperature isotherm and lake area. Shoreline irregularity, watershed area, and river connectivity explained additional variation in some districts. Coherence in ice-out timing within the lakes of each district was consistently strong over this 6 yr period, ranging from r-values of 0.5 to 0.9. Inter-district analysis of coherence also showed synchronous ice-out patterns with the exception of the two arctic coastal districts where ice-out occurs later (June–July) and climatology is sea-ice influenced. These patterns of lake ice phenology provide a spatially extensive baseline describing short-term temporal variability, which will help decipher longer term trends in ice phenology and aid in representing the role of lake ice in land and climate models in northern landscapes.

Lake Tahoe watershed assessment: volume II.

Treesearch

Dennis D. Murphy; Christopher M. Knopp

2000-01-01

This watershed assessment of the Lake Tahoe basin in northern California and Nevada is the first attempt to collate, synthesize, and interpret available scientific information with a comprehensive view toward management and policy outcomes. The seven-chapter report presents new and existing information in subject areas pertinent to policy development and land and...

Lake Tahoe watershed assessment: volume I

Treesearch

Dennis D. Murphy; Christopher M. Knopp

2000-01-01

This watershed assessment of the Lake Tahoe basin in northern California and Nevada is the first attempt to collate, synthesize, and interpret available scientific information with a comprehensive view toward management and policy outcomes. The seven-chapter report presents new and existing information in subject areas pertinent to policy development and land and...

Influence of geomorphic setting on sedimentation of two adjacent alpine lakes, Triglav Lakes Valley (Julian Alps, NW Slovenia)

NASA Astrophysics Data System (ADS)

Smuc, Andrej; Skabene, Dragomir; Muri, Gregor; Vreča, Polona; Jaćimović, Radojko; Čermelj, Branko; Turšič, Janja

2013-04-01

The Triglav Lakes Valley is elongated, 7km long depression, located high (at places over 2000 m.a.s.l.) in the central part of the Julian Alps (NW Slovenia). It hosts 6 small isolated lakes that formed due to the combination of Neogene tectonic and Pleistocene glaciation. The study is focused on the 5th and 6th Triglav Valley Lakes that characterize lower part of the valley. The lakes are located so close to each other that they are even connected in times of high water. Thus, they share the same bedrock geology, are subjected to the same climatic forcing and share similar vegetation communities. Despite their proximity, the lakes differ in their hydrologic and geomorphic setting. The lakes have no permanent surface tributaries; however 5th is fed periodically, at times of high water level, by the Močivec spring, while additional water flows from the swamp area near its northern shore. An underground spring on the eastern side of 5th represents the lake's only permanent freshwater inflow, while drainage takes place to the west via a small ponor. 6th has only one weak underground spring on the eastern side of the lake. Water levels may fluctuate between 2 and 3 m. Additionally, the lakes have different configuration of lakes shores; the northern shores of the 5th lake are low-angle soil and debris covered plateau, while southern shores of the 5th lake and shores of the 6th lake are represented by heavily karstified carbonate base rock and covered partly by trees. The detailed sedimentary analysis of the lakes record showed some similarities, but also some significant differences. Sediments of both lakes are represented by fine-grained turbidity current deposits that are transported from lake shores during snow melt or storms. The grain-size and sedimentary rates of the lakes are however markedly different. The 5th lake has coarser grained sediments, with mean ranging from 46 to 60 µm and records higher sedimentation rates of ~0,57 cm/year, compared to the 6th lake

Potential area for floating net fishery in Lake Toba

NASA Astrophysics Data System (ADS)

Rustini, H. A.; Harsono, E.; Ridwansyah, I.

2018-02-01

Lake Toba in North Sumatera, Indonesia, is now designated to be a world-class tourism destination. Aside from its infrastructure development, this largest lake in the Southeast Asia needs to be restored, especially its water quality. While an oligotrophic status is required for tourism purposes, several studies showed that Toba is mesotrophic at its best and hyper-eutrophic at its worst. Numerous studies and reports blame floating net fishery (FNF) for water quality decline in Lake Toba and propose limitation for its production. While the central government allowed FNF to be positioned in certain areas according to its depth and distance from the lakeshore, increasing number of FNF means adding more nutrients to the lake and thus may inhibit the lake’s restoration process. Hence, it is important to identify which areas are potential for FNF location to assist the authorities to regulate FNF. This study used SPOT-6, SPOT-7, and Pleiades satellite imagery to locate the position of existing FNF and to analyse the result to identify a potential location for FNF.

Lake level and climate records of the last 90 ka from the Northern Basin of Lake Van, eastern Turkey

NASA Astrophysics Data System (ADS)

Çağatay, M. N.; Öğretmen, N.; Damcı, E.; Stockhecke, M.; Sancar, Ü.; Eriş, K. K.; Özeren, S.

2014-11-01

Sedimentary, geochemical and mineralogical analyses of the ICDP cores recovered from the Northern Basin (NB) of Lake Van provide evidence of lake level and climatic changes related to orbital and North Atlantic climate system over the last 90 ka. High lake levels are generally observed during the interglacial and interstadial periods, which are marked by deposition of varved sediments with high total organic carbon (TOC), total inorganic carbon (TIC), low detrital influx (high Ca/F) and high δ18O and δ13C values of authigenic carbonate. During the glacial and stadial periods of 71-58 ka BP (Marine Isotope Stage 4, MIS4) and end of last glaciation-deglaciation (30-14.5 ka BP; MIS3) relatively low lake levels prevailed, and grey homogeneous to faintly laminated clayey silts were deposited at high sedimentation and low organic productivity rates. Millennial-scale variability of the proxies during 60-30 ka BP (MIS3 is correlated with the Dansgaard-Oeschger (D-O)) and Holocene abrupt climate events in the Atlantic. These events are characterized by laminated sediments, with high TOC, TIC, Ca/Fe, δ18O and δ13C values. The Lake Van NB records correlate well in the region with the climate records from the lakes Zeribar and Urmia in Iran and the Sofular Cave in NW Anatolia, but are in general in anti-phase to those from the Dead Sea Basin (Lake Lisan) in the Levant. The relatively higher δ18O values (0 to -0.4‰) for the interglacial and interstadial periods in the Lake Van NB section are due to the higher temperature and seasonality of precipitation and higher evaporation, whereas the lower values (-0.8 to -2‰) during the glacial and stadial periods are caused mainly by relative decrease in both temperature and seasonality of precipitation. The high δ18O values (up to 4.2‰) during the Younger Dryas, together with the presence of dolomite and low TOC contents, supports evaporative conditions and low lake level. A gradual decrease in the δ18O values from an

Forest resources within the Lake States ceded territories 1980 - 2013

Treesearch

Cassandra M. Kurtz; W. Keith Moser; Mark H. Hansen; Dale D. Gormanson; Mark A. Hatfield; Paul A. Sowers; Michael J. Dockry; Marla R. Emery; Christopher W. Woodall; Brian F. Walters; Grant M. Domke; Jonathan Gilbert; Alexandra Wrobel

2015-01-01

The Lake States ceded territories are the portions of northern Michigan, northeastern Minnesota, and northern Wisconsin that were ceded by tribes of the Ojibwe to the government of the United States of America in the treaties of 1836, 1837, 1842, and 1854. The tribes retain rights to hunt, fish, and gather in the 1837, 1842, and 1854 treaty areas. This report...

Cosmogenic 10Be Dating of Northern Quebec-Labrador Glacial Lake Shorelines and Drainage Deposits: Implications for the Final Meltwater Discharges of the Last Deglaciation

NASA Astrophysics Data System (ADS)

Roy, M.; Dube-Loubert, H.; Schaefer, J. M.; Hébert, S.

2017-12-01

The decay of the Laurentide ice sheet played an important role in the climate variability of the last deglaciation, notably through large discharges of meltwater from glacial lakes that disturbed the Atlantic meridional overturning oceanic circulation (AMOC). These former climate-forcing events are now under focus due to growing evidence showing that the present-day increase in freshwater releases from Greenland and other Arctic glaciers may potentially lead to a slowdown of the AMOC and cause important climate feedbacks. In northern Quebec and Labrador, the end of the deglaciation led to the formation of at least 10 important glacial lakes that drained into the nearby Labrador Sea where repeated meltwater discharges could have destabilized the ocean surface conditions in this key sector of the North Atlantic Ocean. Although the drainage of these ice-dammed lakes may form a good analogue for modern processes, the lack of direct constraints on the physiographic configuration and temporal evolution of these lakes limits our understanding of the timing and climate impact of these final meltwater pulses. Here we applied cosmogenic 10Be dating to raised boulder shorelines belonging to Lake Naskaupi, one of the largest glacial lakes in northern Quebec and Labrador. We reconstructed the lake extent and meltwater volume, as well as its lake-level history by systematic mapping of geomorphic features. We sampled a total of 16 boulders at 4 sites along the valley. In addition, we dated five boulders belonging to a large-scale outburst flood deposit recording the abrupt drainage of the lake. The distribution of the 21 ages shows a remarkable consistency, yielding a mean age of 7.8 ± 0.4 ka (1 outlier excluded). The ages from the shorelines are indistinguishable from those of the outburst flood deposit, suggesting that Lake Naskaupi existed for a relatively short time span. These new chronological data constrain the timing of the lake development and attendant drainage

Climatic warming and overgrazing induced the high concentration of organic matter in Lake Hulun, a large shallow eutrophic steppe lake in northern China.

PubMed

Chen, Xiaofeng; Chuai, Xiaoming; Yang, Liuyan; Zhao, Huiying

2012-08-01

An abnormally high concentration of organic matter (OM) in Lake Hulun, a large shallow eutrophic lake located in the sparsely populated Hulun Buir Steppe, was observed in a field investigation. Little was known about the origin of the OM. To identify the source of the OM in Lake Hulun, the carbon/nitrogen (C/N) ratio, natural abundance of stable isotope and three dimensional excitation emission matrix (3DEEM) fluorescence spectroscopy techniques were employed. Furthermore, a cyanobacterial incubation and degradation experiment was conducted in the laboratory to quantify the contribution of algae to dissolved organic matter (DOM) in Lake Hulun. C/N, the stable carbon isotope (δ(13)C) values typical of C3 plant debris in particulate organic matter (POM) and the fluorescence indices of DOM indicate that most of the OM in Lake Hulun is of terrigenous origin. It was deduced that only about 10.2% and 7.3% of DOM were contributed by algae in September and January, respectively, according to the linear correlation between the concentrations of algae-derived DOM and the fluorescence intensities of tyrosine-like matter. According to the stockbreeding development and climate change in Hunlun Buir Steppe, we deduced that the destruction of the grassland ecosystem by overgrazing in specific locations and trends in climatic warming and drying were the main factors causing the increase of OM and nutrient concentrations in Lake Hulun. This result highlights the need to pay more attention to the inputs of terrigenous organic matter to the lakes in northern China. Copyright © 2012 Elsevier B.V. All rights reserved.

What to do with northern hardwood-aspen mixtures

Treesearch

Richard M. Godman

1992-01-01

The aspen type covers the most area in the Lake States, followed by northern hardwoods. Both prefer good soil and are easy to regenerate. Because of past cutting practices, though, the types are now mixed over large areas. Usually there is an overstory of fast-growing aspen interspersed with an understory of dense hardwoods.

The oscillating fringe and paleo-intensity of the East Asian monsoon reconstructed using closed-basin lake-area and dDwax

NASA Astrophysics Data System (ADS)

Goldsmith, Y.; Broecker, W. S.; Polissar, P. J.; Xu, H.; Lan, J.; Zhou, W.; An, Z.; deMenocal, P. B.

2016-12-01

The magnitude, rate and extent of East Asian Monsoon (EAM) rainfall changes during the late Pleistocene-Holocene is reconstructed using the first well-dated northeastern China lake-area record from a closed-lake basin, which enables reconstructing quantitative absolute paleo-rainfall amounts. In addition, compound specific hydrogen isotopes (dDwax) from lake-sediments are used to reconstruct the isotopic composition of rainwater (dP). Lake-levels were 60m higher than present during the early and middle Holocene. Requiring an absolute increase in mean annual rainfall to at least two times higher than today and a 400 km northward expansion. The EAM intensity and northern extent alternated abruptly between wet and dry periods on time scales of a few centuries. Both the onset ( 60 m rise at 11.5 ka BP) and termination ( 35 m drop at 5.5 ka BP) of the Holocene humid period occurred abruptly, within centuries. dDwax is negatively correlated with the lake area record (R2=0.77), showing for the first time, the co-evolution of dP and local rainfall amount. Lake level is also highly correlated with Both North and South Chinese stalagmite records. These results indicate that local distillation is a significant control on dP in East China, and that local rainfall amount is correlated with the intensity of the large EAM system. These results resolve a current debate regarding the use of dP as a proxy for rainfall amount and validate the "intensity-based" interpretations of the Chinese cave deposit records. The lake is located at the modern NW boundary of the EAM, therefore, lake level is governed by the northward extent of the EAM. The covariation of lake level and the intensity of the monsoon indicate that intensity and northward expansion of the EAM are linked and that during intense (weak) EAM periods the EAM northwestern boundary shifts northward (southward).

Study of the wide area of a lake with remote sensing

NASA Astrophysics Data System (ADS)

Lazaridou, Maria A.; Karagianni, Aikaterini C.

2016-08-01

Water bodies are particularly important for environment and development issues. Their study requires multiple information. Remote sensing has been proven useful in the above study. This paper concerns the wide area of Lake Orestiada in the region of Western Macedonia in Greece. The area is of particular interest because Lake Orestiada is included in the Natura 2000 network and is surrounded by diverse landcovers as built up areas and agricultural land. Multispectral and thermal Landsat 5 satellite images of two time periods are being used. Their processing is being done by Erdas Imagine software. The general physiognomy of the area and the lake shore are examined after image enhancement techniques and image interpretation. Directions of the study concern geomorphological aspects, land covers, estimation of surface temperature as well as changes through time.

Enrichment of fluoride in groundwater under the impact of saline water intrusion at the salt lake area of Yuncheng basin, northern China

NASA Astrophysics Data System (ADS)

Gao, Xubo; Wang, Yanxin; Li, Yilian; Guo, Qinghai

2007-12-01

Long-term intake of high-fluoride groundwater causes endemic fluorosis. This study, for the first time, discovered that the salt lake water intrusion into neighboring shallow aquifers might result in elevation of fluoride content of the groundwater. Two cross-sections along the groundwater flow paths were selected to study the geochemical processes controlling fluoride concentration in Yuncheng basin, northern China. There are two major reasons for the observed elevation of fluoride content: one is the direct contribution of the saline water; the other is the undersaturation of the groundwater with respect to fluorite due to salt water intrusion, which appears to be more important reason. The processes of the fluorine activity reduction and the change of Na/Ca ratio in groundwater induced by the intrusion of saline water favor further dissolution of fluorine-bearing mineral, and it was modeled using PHREEQC. With the increase in Na concentration (by adding NaCl or Na2SO4 as Na source, calcium content kept invariable), the increase of NaF concentration was rapid at first and then became slower; and the concentrations of HF, HF{2/-}, CaF+, and MgF+ were continuously decreasing. The geochemical conditions in the study area are advantageous to the complexation of F- with Na+ and the decline of saturation index of CaF2, regardless of the water type (Cl-Na or SO4-Na type water).

Extraction and representation of nested catchment areas from digital elevation models in lake-dominated topography

NASA Astrophysics Data System (ADS)

Mackay, D. Scott; Band, Lawrence E.

1998-04-01

This paper presents a new method for extracting flow directions, contributing (upslope) areas, and nested catchments from digital elevation models in lake-dominated areas. Existing tools for acquiring descriptive variables of the topography, such as surface flow directions and contributing areas, were developed for moderate to steep topography. These tools are typically difficult to apply in gentle topography owing to limitations in explicitly handling lakes and other flat areas. This paper addresses the problem of accurately representing general topographic features by first identifying distinguishing features, such as lakes, in gentle topography areas and then using these features to guide the search for topographic flow directions and catchment marking. Lakes are explicitly represented in the topology of a watershed for use in water routing. Nonlake flat features help guide the search for topographic flow directions in areas of low signal to noise. This combined feature-based and grid-based search for topographic features yields improved contributing areas and watershed boundaries where there are lakes and other flat areas. Lakes are easily classified from remotely sensed imagery, which makes automated representation of lakes as subsystems within a watershed system tractable with widely available data sets.

Late Cenozoic lacustrine and climatic environments at Tule Lake, northern Great Basin, USA

USGS Publications Warehouse

Platt, Bradbury J.

1992-01-01

Cores of lake sediment to a depth of 334 m in the town of Tulelake, Siskiyou County, northern California, document the late Cenozoic paleolimnologic and paleoclimatic history of the northwestern edge of the Great Basin. The cores have been dated by radiometric, tephrochronologic and paleomagnetic analyses. Lacustrine diatoms are abundant throughout the record and document a nearly continuous paleolimnologic history of the Tule Lake basin for the last 3 Myr. During most of this time, this basin (Tule Lake) was a relatively deep, extensive lake. Except for a drier (and cooler?) interval recorded by Fragilaria species about 2.4 Ma, the Pliocene is characterized by a dominance of planktonic Aulacoseira solida implying a warm monomictic lake under a climatic regime of low seasonality. Much of the Pleistocene is dominated by Stephanodiscus and Fragilaria species suggesting a cooler, often drier, and highly variable climate. Benthic diatoms typical of alkaline-enriched saline waters commonly appear after 1.0 Ma, and tephrochronology indicates slow deposition and possible hiatuses between about 0.6 and 0.2 Ma. The chronology of even-numbered oxygen isotope stages approximately matches fluctuations in the abundance of Fragilaria since 800 ka indicating that glacial periods were expressed as drier environments at Tule Lake. Glacial and interglacial environments since 150 ka were distinct from, and more variable than, those occurring earlier. The last full glacial period was very dry, but shortly thereafter Tule Lake became a deep, cool lacustrine system indicating a substantial increase in precipitation. Aulacoseira ambigua characterized the latest glacial and Holocene record of Tule Lake. Its distribution indicates that warmer and wetter climates began about 15 ka in this part of the Great Basin. Diatom concentration fluctuates at 41 000 year intervals between 3.0 and 2.5 Ma and at approximately 100 000 year intervals after 1.0 Ma. In the late Pliocene and early Pleistocene

Trace element exposure of whooper swans (Cygnus cygnus) wintering in a marine lagoon (Swan Lake), northern China.

PubMed

Wang, Feng; Xu, Shaochun; Zhou, Yi; Wang, Pengmei; Zhang, Xiaomei

2017-06-30

Trace element poisoning remains a great threat to various waterfowl and waterbirds throughout the world. In this study, we determined the trace element exposure of herbivorous whooper swans (Cygnus cygnus) wintering in Swan Lake (Rongcheng), an important swan protection area in northern China. A total of 70 samples including abiotic factors (seawater, sediments), food sources (seagrass, macroalgae), feathers and feces of whooper swans were collected from the marine lagoon during the winters of 2014/2015 and 2015/2016. Concentrations of Cu, Zn, Pb, Cr, Cd, Hg and As were determined to investigate the trace element exposure of whooper swans wintering in the area. Results showed that there was an increasing trend in sediment trace element concentrations, compared with historical data. The trace element concentrations in swan feces most closely resembled those of Zostera marina leaves, especially for Cd and Cr. The Zn and Hg concentrations in the swan feces (49.57 and 0.01mg/kg, respectively) were lower than the minimum values reported in the literature for other waterfowls, waterbirds and terrestrial birds. However, the concentrations of the other five trace elements fell within the lower and mediate range of values reported for birds across the world. These results suggest that the whooper swans wintering in Swan Lake, Rongcheng are not suffering severe trace element exposure; however, with the increasing input of trace elements to the lagoon, severe adverse impacts may occur in the future, and we therefore suggest that the input of trace elements to this area should be curbed. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Hazardous radioactivity levels and heavy mineral concentrations in beach sediments of Lake Peipsi, northeastern Estonia

NASA Astrophysics Data System (ADS)

Järvelill, Johanna-Iisebel; Koch, Rein; Raukas, Anto; Vaasma, Tiit

2018-03-01

The present study discusses results of heavy mineral analyses and radioactivity of beach sediments of Lake Peipsi. Such analyses are commonly done globally, but had not yet been conducted for the fourth largest lake in Europe. The average heavy mineral content in Lake Peipsi beach sediments along the northern and western coast is higher than usual for Estonian coastal and Quaternary sediments. Concomitantly, elevated radioactivity levels have been measured in several places, with the highest concentrations observed at Alajõe (1885.5 Bq/kg), which is over five times more than the recommended limit. The aim of the present study is to find sites with higher radioactivity levels, because the northern coast of Lake Peipsi is a well-known recreational area.

Special places in the Lake Calumet area.

Treesearch

Herbert W. Schroeder

2004-01-01

An open-ended, qualitative survey was conducted to identify special places in the Lake Calumet area of northeastern Illinois and northwestern Indiana, and to learn what kinds of experiences and environmental features make these places memorable and important to people.

How willing are landowners to supply land for bioenergy crops in the Northern Great Lakes Region?

DOE PAGES

Swinton, Scott M.; Tanner, Sophia; Barham, Bradford L.; ...

2016-04-30

Land to produce biomass is essential if the United States is to expand bioenergy supply. Use of agriculturally marginal land avoids the food vs. fuel problems of food price rises and carbon debt that are associated with crop and forestland. Recent remote sensing studies have identified large areas of US marginal land deemed suitable for bioenergy crops. Yet the sustainability benefits of growing bioenergy crops on marginal land only pertain if land is economically available. Scant attention has been paid to the willingness of landowners to supply land for bioenergy crops. Focusing on the northern tier of the Great Lakes,more » where grassland transitions to forest and land prices are low, this contingent valuation study reports on the willingness of a representative sample of 1124 private, noncorporate landowners to rent land for three bioenergy crops: corn, switchgrass, and poplar. Of the 11% of land that was agriculturally marginal, they were willing to make available no more than 21% for any bioenergy crop (switchgrass preferred on marginal land) at double the prevailing land rental rate in the region. At the same generous rental rate, of the 28% that is cropland, they would rent up to 23% for bioenergy crops (corn preferred), while of the 55% that is forestland, they would rent up to 15% for bioenergy crops (poplar preferred). Regression results identified deterrents to land rental for bioenergy purposes included appreciation of environmental amenities and concern about rental disamenities. In sum, like landowners in the southern Great Lakes region, landowners in the Northern Tier are reluctant to supply marginal land for bioenergy crops. If rental markets existed, they would rent more crop and forestland for bioenergy crops than they would marginal land, which would generate carbon debt and opportunity costs in wood product and food markets.« less

How willing are landowners to supply land for bioenergy crops in the Northern Great Lakes Region?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swinton, Scott M.; Tanner, Sophia; Barham, Bradford L.

Land to produce biomass is essential if the United States is to expand bioenergy supply. Use of agriculturally marginal land avoids the food vs. fuel problems of food price rises and carbon debt that are associated with crop and forestland. Recent remote sensing studies have identified large areas of US marginal land deemed suitable for bioenergy crops. Yet the sustainability benefits of growing bioenergy crops on marginal land only pertain if land is economically available. Scant attention has been paid to the willingness of landowners to supply land for bioenergy crops. Focusing on the northern tier of the Great Lakes,more » where grassland transitions to forest and land prices are low, this contingent valuation study reports on the willingness of a representative sample of 1124 private, noncorporate landowners to rent land for three bioenergy crops: corn, switchgrass, and poplar. Of the 11% of land that was agriculturally marginal, they were willing to make available no more than 21% for any bioenergy crop (switchgrass preferred on marginal land) at double the prevailing land rental rate in the region. At the same generous rental rate, of the 28% that is cropland, they would rent up to 23% for bioenergy crops (corn preferred), while of the 55% that is forestland, they would rent up to 15% for bioenergy crops (poplar preferred). Regression results identified deterrents to land rental for bioenergy purposes included appreciation of environmental amenities and concern about rental disamenities. In sum, like landowners in the southern Great Lakes region, landowners in the Northern Tier are reluctant to supply marginal land for bioenergy crops. If rental markets existed, they would rent more crop and forestland for bioenergy crops than they would marginal land, which would generate carbon debt and opportunity costs in wood product and food markets.« less

The use of total lake-surface area as an indicator of climatic change: Examples from the Lahontan basin

USGS Publications Warehouse

Benson, L.V.; Paillet, Frederick L.

1989-01-01

Variation in the size of lakes in the Lahontan basin is topographically constrained. River diversion also has played a major role in regulating lake size in Lahontan subbasins. The proper gage of lake response to change in the hydrologic balance is neither lake depth (level) nor lake volume but instead lake-surface area. Normalization of surface area is necessary when comparing surface areas of lakes in basins having different topographies. To a first approximation, normalization can be accomplished by dividing the paleosurface area of a lake by its mean-historical, reconstructed surface area. ?? 1989.

Volcano Hazards Assessment for Medicine Lake Volcano, Northern California

USGS Publications Warehouse

Donnelly-Nolan, Julie M.; Nathenson, Manuel; Champion, Duane E.; Ramsey, David W.; Lowenstern, Jacob B.; Ewert, John W.

2007-01-01

Medicine Lake volcano (MLV) is a very large shield-shaped volcano located in northern California where it forms part of the southern Cascade Range of volcanoes. It has erupted hundreds of times during its half-million-year history, including nine times during the past 5,200 years, most recently 950 years ago. This record represents one of the highest eruptive frequencies among Cascade volcanoes and includes a wide variety of different types of lava flows and at least two explosive eruptions that produced widespread fallout. Compared to those of a typical Cascade stratovolcano, eruptive vents at MLV are widely distributed, extending 55 km north-south and 40 km east-west. The total area covered by MLV lavas is >2,000 km2, about 10 times the area of Mount St. Helens, Washington. Judging from its long eruptive history and its frequent eruptions in recent geologic time, MLV will erupt again. Although the probability of an eruption is very small in the next year (one chance in 3,600), the consequences of some types of possible eruptions could be severe. Furthermore, the documented episodic behavior of the volcano indicates that once it becomes active, the volcano could continue to erupt for decades, or even erupt intermittently for centuries, and very likely from multiple vents scattered across the edifice. Owing to its frequent eruptions, explosive nature, and proximity to regional infrastructure, MLV has been designated a 'high threat volcano' by the U.S. Geological Survey (USGS) National Volcano Early Warning System assessment. Volcanic eruptions are typically preceded by seismic activity, but with only two seismometers located high on the volcano and no other USGS monitoring equipment in place, MLV is at present among the most poorly monitored Cascade volcanoes.

75 FR 22228 - Regulated Navigation Area; Lake Champlain Bridge Construction Zone, NY and VT

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-28

...-AA11 Regulated Navigation Area; Lake Champlain Bridge Construction Zone, NY and VT AGENCY: Coast Guard... establishing a regulated navigation area around the construction zone of the Lake Champlain Bridge between... on all vessels transiting the navigable waters of Lake Champlain in the vicinity of the bridge...

New records of late Holocene tephras from Lake Futalaufquen (42.8°S), northern Patagonia

NASA Astrophysics Data System (ADS)

Daga, Romina; Ribeiro Guevara, Sergio; Arribére, María

2016-03-01

In regions with limited knowledge of the historical volcanic record, like remote areas in the Andean Southern Volcanic Zone, the definition of reliable age-depth models for lake sequences represents a valuable tool for tephra layers dating. In Lake Futalaufquen (42.8°S), Northern Patagonia, a short sedimentary sequence was extracted after the AD 2008 Chaitén eruption with the purpose to analyze the records of volcanic eruptions at these poorly studied latitudes. The sequence was dated by 210Pb, 137Cs, and 14C techniques. Five tephras were identified for the last 1600 years, restricted to the last 5 centuries. Sedimentology, morphology, and geochemical properties allowed the characterization of the tephras and their correlation with tephras recently identified proximal to the sources, mainly from Chaitén and Huequi volcanoes, and Michinmahuida accessory cones, representing the first distal records reported of these tephras. Furthermore, tephras modeled ages obtained by the sequence age-depth model shrink the ages for the volcanic events, like a potential cycle of activity from Michinmauida accessory cones during AD 1530 ± 55, one eruption from Huequi volcano at AD 1695 ± 50, and a possible recent eruption from Chaitén at AD 1775 ± 40. Additionally, the work contributes to improve the regional volcanic records knowledge, basic for volcanic hazard assessment.

Lakes in the greater Denver area, Front Range Urban Corridor

USGS Publications Warehouse

Danielson, T.W.

1975-01-01

The purpose of this report is to present the results of an inventory of the lakes in the central one-third of the Colorado Front Range Urban Corridor. This inventory provides information that might be helpful in planning the best and most beneficial use of lakes in an area of rapid population growth. The report includes data on lake size and water quality. Size data are included on most of the lakes of 2 hectares (20,000 m2, or about 5 acres) or greater, and water-quality data are provided on most lakes larger than 10 hectares (about 25 acres). Bodies of water resulting form excavation of gravel (borrow pits) were generally not included in the inventory.

Earthshots: Satellite images of environmental change – Lake Urmia, Iran

USGS Publications Warehouse

Adamson, Thomas

2015-01-01

The lake’s southern basin is shallower than its northern basin, so recent images show the water disappearing from the southern basin first. These Landsat images use the shortwave-infrared, near-infrared, and green wavelengths of light. Because water absorbs infrared light, water (dark blue to black) contrasts with the surrounding land areas. As the water becomes shallower, light is reflected off of the lakebed in shades of light blue. Lighter blue and bright areas immediately surrounding the lake are where the receding shoreline has exposed the lake bottom.

Lake Pontchartrain Area/New Orleans (Louisiana) Meetings & Events

EPA Pesticide Factsheets

Lake Pontchartrain Area/New Orleans (Louisiana) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating with community-led efforts

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.

The impact of lake level variation on seismicity around XianNvShan fault in the Three Gorge area

NASA Astrophysics Data System (ADS)

Liao, W.; Li, J.; Zhang, L.

2017-12-01

Since the impounding of Three Gorge Project in 2003,more than 10000 earthquakes have been recorded by the digital telemetry seismic network. Most of them occurred around the GaoQiao fault and the Northern segment of XianNvShan fault . In March 2014, the M4.3 and M4.7 earthquake happened in the northern segment of Xiannvshshan fault .In order to study the relationship between the seismicity around the XianNvShan fault and the lake level variation, we had been deployed 5 temporal seismic stations in this area from 2015 to 2016. More than 3000 earthquakes recorded during the time of temporal seismic monitoring are located by hypo-center of by waveform cross-correlation and double-difference method. The depth of most earthquakes is from 5 to 7 km.but it is obvious that the variation of depth is relate to the fluctuation of water level.

Plants as indicators of focused ground water discharge to a northern Minnesota lake

USGS Publications Warehouse

Rosenberry, D.O.; Striegl, Robert G.; Hudson, D.C.

2000-01-01

Determining the discharge of ground water to Shingobee Lake (66 ha), north-central Minnesota, is complicated by the presence of numerous springs situated adjacent to the lake and in the shallow portion of the lakebed. Springs first had to be located before these areas of more rapid discharge could be quantified. Two methods that rely on the distribution of aquatic plants are useful for locating springs. One method identifies areas of the near-shore lakebed where floating-leaf and emergent aquatic vegetation are absent. The second method uses the distribution of marsh marigold (Caltha palustris L.) to locate springs that discharge on land near the shoreline of the lake. Marsh marigold produces large (2 to 4 cm diameter) yellow flowers that provide a ready marker for locating ground water springs. Twice as many springs (38) were identified using this method as were identified using the lack of near-shore vegetation. A portable weir was used to measure discharge from onshore springs, and seepage meters were used to measure discharge from near-shore springs. Of the total 56.7 L s-1 that enters the lake from ground water, approximately 30% comes from onshore and near-shore springs.Determining the discharge of ground water to Shingobee Lake (66 ha), north-central Minnesota, is complicated by the presence of numerous springs situated adjacent to the lake and in the shallow portion of the lakebed. Springs first had to be located before these areas of more rapid discharge could be quantified. Two methods that rely on the distribution of aquatic plants are useful for locating springs. One method identifies areas of the near-shore lakebed where floating-leaf and emergent aquatic vegetation are absent. The second method uses the distribution of marsh marigold (Caltha palustris L.) to locate springs that discharge on land near the shoreline of the lake. Marsh marigold produces large (2 to 4 cm diameter) yellow flowers that provide a ready marker for locating ground water

Identification of hot spot area of sediment contamination in a lake system using texture characteristics.

PubMed

Sheela, A M; Letha, J; Joseph, Sabu; Thomas, Jobin

2013-04-01

Texture plays an important role in the identification of polluted stretch in a lake system. The organic matter as well as toxic elements get accumulated in the finer sediments. The aim of the work is to show the spatio-temporal distribution of texture of the lake sediment (Akkulam-Veli lake, Kerala) and to identify the hot spot areas of contamination. Hot spot areas vary with seasons. During PRM, (premonsoon), the upstream portion of the Akkulam lake is the hot spot. During MON (monsoon), the downstream portion of the Akkulam lake and the upstream portion of the Veli lake are the hot spots. During POM (postmonsoon), hot spot area is the downstream portion of the Akkulam lake. This methodology can be used for the quick identification of hot spots in water bodies.

The Archaeology of Coralville Lake, Iowa. Volume 4. Recreation Area Survey. (Interim Report 2).

DTIC Science & Technology

1985-09-01

THE ARCHAEOLOGY OF CORALVILLE LAKE, IOWA VOLUME IV: RECREATION AREA SURVEY (INTERIM REPORT II) p - [ JAN 1 4 1986 WAUWATOSA. WISCONSIN 86 1.13 117...THE ARCHAEOLOGY OF CORALVILLE LAKE, IOWA ; VOLUME IV: RECREATION AREA SURVEY (INTERIM REPORT II) Submitted To: Rock Island District Corps of Engineers...presents the results of intensive archaeological and geomorphic investigations at 14 special use or recreation areas at Coralville Lake, Iowa . The

Feeding ecology of pelagic larval Burbot in Northern Lake Huron, Michigan

USGS Publications Warehouse

George, Ellen M.; Roseman, Edward F.; Davis, Bruce M.; O'Brien, Timothy P.

2013-01-01

Burbot Lota lota are a key demersal piscivore across the Laurentian Great Lakes whose populations have declined by about 90% in recent decades. Larval Burbot typically hatch in the early spring and rely on abundant crustacean zooplankton prey. We examined the stomach contents of larval Burbot from inshore (≤15 m) and offshore sites (37 and 91 m) in northern Lake Huron, Michigan. Concurrent zooplankton vertical tows at the same sites showed that the prey community was dominated by calanoid copepods, dreissenid mussel veligers, and rotifers. Burbot consumed mostly cyclopoid copepods, followed by copepod nauplii and calanoid copepods. Chesson's index of selectivity was calculated and compared among sites and months for individual Burbot. According to this index, larval Burbot exhibited positive selection for cyclopoid copepods and copepod nauplii and negative selection for calanoid copepods, cladocerans, rotifers, and dreissenid veligers. This selectivity was consistent across sites and throughout the sampling period. Burbot displayed little variation in their prey preferences during the larval stage, which suggests that the recent shifts in zooplankton abundance due to the invasion of the predatory zooplankter Bythotrephes longimanus and competition from invasive Rainbow Smelt Osmerus mordax could negatively impact larval Burbot populations.

Effectiveness of terrestrial protected areas for conservation of lake fish communities.

PubMed

Chu, Cindy; Ellis, Lucy; de Kerckhove, Derrick T

2018-06-01

Freshwater protected areas are rare even though freshwater ecosystems are among the most imperiled in the world. Conservation actions within terrestrial protected areas (TPAs) such as development or resource extraction regulations may spill over to benefit freshwater ecosystems within their boundaries. Using data from 175 lakes across Ontario, Canada, we compared common indicators of fish-assemblage status (i.e., species richness, Shannon diversity index, catch per unit effort, and normalized-length size spectrum slopes) to evaluate whether TPAs benefit lake fish assemblages. Nearest neighbor cluster analysis was used to generate pairs of lakes: inside versus outside, inside versus bordering, and bordering versus outside TPAs based on lake characteristics. The diversity and abundance indicators did not differ significantly across comparisons, but normalized-length size spectrum slopes (NLSS) were significantly steeper in lakes outside parks. The latter indicated assemblage differences (greater abundances of small-bodied species) and less-efficient energy transfer through the trophic levels of assemblages outside parks. Although not significantly different, pollution- and turbidity-tolerant species were more abundant outside parks, whereas 3 of the 4 pollution-intolerant species were more abundant within parks. Twenty-one percent of the difference in slopes was related to higher total dissolved solids concentrations and angling pressure. Our results support the hypothesis that TPAs benefit lake fish assemblages and suggest that NLSS slopes are informative indicators for aquatic protected area evaluations because they represent compositional and functional aspects of communities. © 2017 Society for Conservation Biology.

A proposed aquatic plant community biotic index for Wisconsin lakes

USGS Publications Warehouse

Nichols, S.; Weber, S.; Shaw, B.

2000-01-01

The Aquatic Macrophyte Community Index (AMCI) is a multipurpose tool developed to assess the biological quality of aquatic plant communities in lakes. It can be used to specifically analyze aquatic plant communities or as part of a multimetric system to assess overall lake quality for regulatory, planning, management, educational, or research purposes. The components of the index are maximum depth of plant growth; percentage of the littoral zone vegetated; Simpson's diversity index; the relative frequencies of submersed, sensitive, and exotic species; and taxa number. Each parameter was scaled based on data distributions from a statewide database, and scaled values were totaled for the AMCI value. AMCI values were grouped and tested by ecoregion and lake type (natural lakes and impoundments) to define quality on a regional basis. This analysis suggested that aquatic plant communities are divided into four groups: (1) Northern Lakes and Forests lakes and impoundments, (2) North-Central Hardwood Forests lakes and impoundments, (3) Southeastern Wisconsin Till Plains lakes, and (4) Southeastern Wisconsin Till Plains impoundments, Driftless Area Lakes, and Mississippi River Backwater lakes. AMCI values decline from group 1 to group 4 and reflect general water quality and human use trends in Wisconsin. The upper quartile of AMCI values in any region are the highest quality or benchmark plant communities. The interquartile range consists of normally impacted communities for the region and the lower quartile contains severely impacted or degraded plant communities. When AMCI values were applied to case studies, the values reflected known impacts to the lakes. However, quality criteria cannot be used uncritically, especially in lakes that initially have low nutrient levels.The Aquatic Macrophyte Community Index (AMCI) is a multipurpose tool developed to assess the biological quality of aquatic plant communities in lakes. It can be used to specifically analyze aquatic plant

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.

Glacial lakes of the Central and Patagonian Andes

NASA Astrophysics Data System (ADS)

Wilson, Ryan; Glasser, Neil F.; Reynolds, John M.; Harrison, Stephan; Anacona, Pablo Iribarren; Schaefer, Marius; Shannon, Sarah

2018-03-01

The prevalence and increased frequency of high-magnitude Glacial Lake Outburst Floods (GLOFs) in the Chilean and Argentinean Andes suggests this region will be prone to similar events in the future as glaciers continue to retreat and thin under a warming climate. Despite this situation, monitoring of glacial lake development in this region has been limited, with past investigations only covering relatively small regions of Patagonia. This study presents new glacial lake inventories for 1986, 2000 and 2016, covering the Central Andes, Northern Patagonia and Southern Patagonia. Our aim was to characterise the physical attributes, spatial distribution and temporal development of glacial lakes in these three sub-regions using Landsat satellite imagery and image datasets available in Google Earth and Bing Maps. Glacial lake water volume was also estimated using an empirical area-volume scaling approach. Results reveal that glacial lakes across the study area have increased in number (43%) and areal extent (7%) between 1986 and 2016. Such changes equate to a glacial lake water volume increase of 65 km3 during the 30-year observation period. However, glacial lake growth and emergence was shown to vary sub-regionally according to localised topography, meteorology, climate change, rate of glacier change and the availability of low gradient ice areas. These and other factors are likely to influence the occurrence of GLOFs in the future. This analysis represents the first large-scale census of glacial lakes in Chile and Argentina and will allow for a better understanding of lake development in this region, as well as, providing a basis for future GLOF risk assessments.

Temporal patterns of glacial lake evolution in high-mountain environments

NASA Astrophysics Data System (ADS)

Mergili, Martin; Emmer, Adam; Viani, Cristina; Huggel, Christian

2017-04-01

Lakes forming at the front of retreating glaciers are characteristic features of high-mountain areas in a warming climate. Typically, lakes shift from the proglacial phase (lake is in direct contact with glacier) to a glacier-detached (no direct contact) and finally to a non-glacial phase (lake catchment is completely deglaciated) of lake evolution. Apart from changing glacier-lake interactions, each stage is characterized by particular features of lake growth, and by the lake's susceptibility to sudden drainage (lake outburst flood). While this concept appears to be valid globally, some mountain areas are rich in dynamically evolving proglacial lakes, while in others most lakes have already shifted to the glacier-detached or even non-glacial phase. In the present contribution we (i) explore and quantify the history of glacial lake formation and evolution over the past up to 70 years; (ii) assess the current situation of selected contrasting mountain areas (eastern and western European Alps, southern and northern Pamir, Cordillera Blanca); and (iii) link the patterns of lake evolution to the prevailing topographic and glaciological characteristics in order to improve the understanding of high-mountain geoenvironmental change. In the eastern Alps we identify only very few lakes in the proglacial stage. While many lakes appeared and dynamically evolved until the 1980s between 2550 m and 2800 m asl, most of them have lost glacier contact until the 2000s, whereas very few new proglacial lakes appeared at the same time. Even though a similar trend is observed in the higher western Alps, a more dynamic glacial lake evolution is observed there. The arid southern Pamir is characterized by a high number of proglacial lakes, mainly around 4500 m asl. There is strong evidence that glacial lake evolution is, after a highly dynamic phase between the 1970s and approx. 2000, decelerating. Few proglacial lakes exist in the higher and more humid, heavily glacierized northern Pamir

Occurrence and Distribution of Microcystins in Lake Taihu, China

PubMed Central

Sakai, Hiroshi; Hao, Aimin; Iseri, Yasushi; Wang, Song; Kuba, Takahiro; Zhang, Zhenjia; Katayama, Hiroyuki

2013-01-01

The occurrence and distribution of microcystins were investigated in Lake Taihu, the third largest lake in China. An extensive survey, larger and broader in scale than previous studies, was conducted in summer 2010. The highest microcystin concentration was found at southern part of Taihu, which was newly included in this survey. In northern coastal areas, total cellular concentrations of 20 to 44 μg/L were observed. In northern offshore waters, levels were up to 4.8 μg/L. Microcystin occurrence was highly correlated with chemical oxygen demand, turbidity, and chlorophyll-a. Extracellular/total cellular microcystin (E/T) ratios were calculated and compared to other water quality parameters. A higher correlation was found using E/T ratios than original microcystin values. These results show that algal blooms are having a severe impact on Lake Taihu, and further and extensive monitoring and research are required to suppress blooms effectively. PMID:23853542

AmeriFlux CA-Man Manitoba - Northern Old Black Spruce (former BOREAS Northern Study Area)

DOE Data Explorer

Amiro, Brian [University of Manitoba

2016-01-01

This is the AmeriFlux version of the carbon flux data for the site CA-Man Manitoba - Northern Old Black Spruce (former BOREAS Northern Study Area). Site Description - 55.880° N, 98.481° W, elevation of 259 m, Boreal coniferous: Black spruce; occasional larch present in poorly-drained areas. Groundcover is moss (feathermosses and Sphagnum), Labrador Tea, Vaccinium, and willows are a main component of the understory. It was established in 1993 as a BOREAS site.

Glacier lake outburst floods caused by glacier shrinkage: case study of Ala-Archa valley, Kyrgyz Ala Too, northern Tian Shan, Kyrgyzstan

NASA Astrophysics Data System (ADS)

Petrakov, D.; Erochin, S. A.; Harbor, J.; Ivanov, M.; Rogozhina, I.; Stroeven, A. P.; Usubaliev, R.

2012-12-01

Changes in glacier extent and runoff in Central Asia increase socio-economic stress and may result in political conflict between donors of freshwater (Kyrgyzstan, Tajikistan) and recipients of freshwater (Uzbekistan, China). Glaciers in the Pamir and Tian Shan regions have experienced an unprecedented downwasting due to regional climate changes over the past decades. This is because air temperature increases are in some areas accompanied by a decrease in precipitation. Such conditions have already resulted in a reduction of glacier runoff, especially in the northern and western Tian Shan, and an increase of the number and area of glacial lakes in Kyrgyzstan. Even though glacial lakes in the mountains are in general relatively small and located far from densely populated areas, their outbursts often produce destructive debris flows. Such debris flows are especially common in Kyrgyzstan because of its steep river channels and abundance of Holocene and Quaternary glacier deposits that can be remobilized. The glacial lake outburst flood (GLOF) in the Shakhimardan river catchment in 1999, for example, resulted in 100 fatalities in Uzbekistan, and the GLOF from the Zyndan glacial lake led to substantial economic losses in 2009. According to the latest inventory, there are more than 350 glacial lakes in Kyrgyzstan of which about 70 occur in the Kyrgyz Ala Too. The Ala-Archa valley is among the most important glacierized catchments in Kyrgyzstan. Despite the presence of a relatively small glacier-covered area of 36 km2, the Ala-Archa river is of critical importance to the Bishkek area, its agriculture, and its population which currently exceeds one million. GLOFs are therefore a threat to both numerous settlements of touristic value in the Ala-Archa headwaters and to Bishkek. The Teztor lake in the Adygene catchment of the Ala-Archa river system experienced an outburst during 1988 and 2005. On the early morning of July 31, 2012, this lake began draining through a dam

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

USGS Publications Warehouse

Dorr, John A.; 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.

The food of the lake trout (Cristivomer namaycush namaycush) and of the lawyer (Lota maculosa) of Lake Michigan

USGS Publications Warehouse

Van Oosten, John; Deason, Hilary J.

1938-01-01

This paper reports on a qualitative and quantitative analysis of the contents of 4,979 lake trout stomachs (593 examined in 1930 and 1,253 collected in 1931 from southern Lake Michigan, 1,446 from northern Lake Michigan and 1,687 from Green Bay in 1932), and of a total of 1,528 lawyer stomachs (172 examined in 1930 and 734 collected in 1931 from southern Lake Michigan, 612 from northern Lake Michigan and 10 from Green Bay in 1932). The food of the trout consisted of 98 per cent by volume of fish of which Cottidae and Coregonidae were the principal constituents. Cottidae were dominant in southern Lake Michigan (72 per cent by volume), Coregonidae in northern Lake Michigan (51 per cent) but the lake shiner, Notropis atherinides, was most important in Green Bay in the spring of the year (64 per cent). The lawyer food consisted of 74 per cent by volume of fish and 26 per cent invertebrates. Dominant items were Cottidae (76 per cent by volume) in southern Lake Michigan, Coregonidae (51 per cent) and Pontoporeia (37 per cent) in northern Lake Michigan, and Percopsis (34 per cent) and Mysis (26 per cent) in Green Bay. Data are also presented on the frequency of occurrence (number of stomachs) of the food items and its variation with the sizes of the trout and lawyers, depths of water, seasons, and localities; on the number of individual fish of each species destroyed by the trout and lawyers; and on the calculated volume of the food fishes preceding digestion. The lake trout and lawyer are competitors for the same food, are both predators of the commercially important Coregonidae, and the lawyer through its consumption of invertebrates is a food competitor of the Coregonidae.

Occurrence of pharmaceuticals in municipal wastewater, in the recipient water, and sedimented particles of northern Lake Päijänne.

PubMed

Lindholm-Lehto, Petra C; Ahkola, Heidi S J; Knuutinen, Juha S; Herve, Sirpa H

2015-11-01

The presence of five different pharmaceuticals, consisting of four anti-inflammatory and one antiepileptic drug, was determined in influent and effluent of a municipal wastewater treatment plant (WWTP) near the city of Jyväskylä, Finland, and in the receiving water, northern Lake Päijänne. In addition, samples of sedimented particles were collected among water samples from five locations near the discharge point of the treated wastewater. The solid phase extracts (SPEs) of water samples were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) in the multiple reaction monitoring mode. The studied pharmaceuticals were detected from influent, effluent, and lake water but also in the sedimented particles. The concentrations of carbamazepine, diclofenac, ibuprofen, ketoprofen, and naproxen in Lake Päijänne ranged from 1 to 21 ng L(-1), 4 to 209 ng L(-1), 5 to 836 ng L(-1), 9 to 952 ng L(-1), and 2 to 129 ng L(-1), respectively. The concentrations of ketoprofen in sedimented particles ranged from 79 to 135 μg g(-1) while only trace amounts of other selected pharmaceuticals were detected. The results indicate that the concentrations of pharmaceuticals are affected by the biological and chemical reactions occurring in the wastewater treatment processes but also by the UV light in the photic layer of Lake Päijänne. It can be concluded that considerable amount of selected pharmaceuticals are present in the influent and effluent of municipal WWTP but also in the water phase and sedimented particles of northern Lake Päijänne.

Northern goshawk monitoring in the western Great Lakes bioregion

USGS Publications Warehouse

Bruggeman, Jason E.; Andersen, David E.; Woodford, James E.

2011-01-01

Uncertainties about factors affecting Northern Goshawk (Accipiter gentilis) ecology and the status of populations have added to the challenge of managing this species. To address data needs for determining the status of goshawk populations, Hargis and Woodbridge (2006) developed a bioregional monitoring protocol based on estimating occupancy. The goal of our study was to implement this protocol and collect data to determine goshawk population status in the western Great Lakes (WGL) bioregion, which encompasses portions of Minnesota, Wisconsin, and Michigan, and is a mixture of private and public property. We used 366 goshawk nest locations obtained between 1979 and 2006 throughout the WGL bioregion to develop a model of landscape use consisting of forest canopy cover and land-cover covariates. We then used the model to develop a stratified sampling design for selecting 600-ha Primary Sampling Units (PSUs) to survey for goshawks. Project collaborators surveyed 86 PSUs for goshawk presence using broadcasted calls twice between mid-May and mid-August 2008, and recorded 30 goshawk detections in 21 different PSUs. Seventy-four percent of detections occurred at call stations with canopy closure >75%. Goshawk detection probabilities were 0.549 ± 0.118 (standard error) for the first visit to PSUs and 0.750 ± 0.126 for the second visit. We estimated the proportion of PSUs occupied by goshawks as 0.266 ± 0.047, which corresponded to 5184 ± 914 PSUs occupied by goshawks in our study area and suggested that goshawks are widely, but sparsely, distributed throughout the WGL bioregion.

Hydrogeology, hydrologic budget, and water chemistry of the Medina Lake area, Texas

USGS Publications Warehouse

Lambert, Rebecca B.; Grimm, Kenneth C.; Lee, Roger W.

2000-01-01

A three-phase study of the Medina Lake area in Texas was done to assess the hydrogeology and hydrology of Medina and Diversion Lakes combined (the lake system) and to determine what fraction of seepage losses from the lake system might enter the regional ground-water-flow system of the Edwards and (or) Trinity aquifers. Phase 1 consisted of revising the geologic framework for the Medina Lake area. Results of field mapping show that the upper member of the Glen Rose Limestone underlies Medina Lake and the intervening stream channel from the outflow of Medina Lake to the midpoint of Diversion Lake, where the Diversion Lake fault intersects Diversion Lake. A thin sequence of strata consisting primarily of the basal nodular and dolomitic members of the Kainer Formation of the Edwards Group, is present in the southern part of the study area. On the southern side of Medina Lake, the contact between the upper member of the Glen Rose Limestone and the basal nodular member is approximately 1,000 feet above mean sea level, and the contact between the basal nodular member and the dolomitic member is approximately 1,050 feet above mean sea level. The most porous and permeable part of the basal nodular member is about 1,045 feet above mean sea level. At these altitudes, Medina Lake is in hydrologic connection with rocks in the Edwards aquifer recharge zone, and Medina Lake appears to lose more water to the ground-water system along this bedding plane contact. Hydrologic budgets calculated during phase 2 for Medina Lake, Diversion Lake, and Medina/Diversion Lakes combined indicate that: (1) losses from Medina and Diversion Lakes can be quantified; (2) a portion of those losses are entering the Edwards aquifer; and (3) losses to the Trinity aquifer in the Medina Lake area are minimal and within the error of the hydrologic budgets. Hydrologic budgets based on streamflow, precipitation, evaporation, and change in lake storage were used to quantify losses (recharge) to the ground

Methods to assess natural and anthropogenic thaw lake drainage on the western Arctic coastal plain of northern Alaska

USGS Publications Warehouse

Hinkel, Kenneth M.; Jones, Benjamin M.; Eisner, Wendy R.; Cuomo, Chris J.; Beck, R.A.; Frohn, R.

2007-01-01

Thousands of lakes are found on the Arctic Coastal Plain of northern Alaska and northwestern Canada. Developed atop continuous permafrost, these thaw lakes and associated drained thaw lake basins are the dominant landscape elements and together cover 46% of the 34,570 km2western Arctic Coastal Plain (WACP). Lakes drain by a variety of episodic processes, including coastal erosion, stream meandering, and headward erosion, bank overtopping, and lake coalescence. Comparison of Landsat multispectral scanner (MSS) imagery from the mid-1970s to Landsat 7 enhanced thematic mapper (ETM+) imagery from around 2000 shows that 50 lakes completely or partially drained over the approximately 25 year period, indicating landscape stability. The lake-specific drainage mechanism can be inferred in some cases and is partially dependant on geographic settings conducive to active erosion such as riparian and coastal zones. In many cases, however, the cause of drainage is unknown. The availability of high-resolution aerial photographs for the Barrow Peninsula extends the record back to circa 1950; mapping spatial time series illustrates the dynamic nature of lake expansion, coalescence, and drainage. Analysis of these historical images suggests that humans have intentionally or inadvertently triggered lake drainage near the village of Barrow. Efforts to understand landscape processes and identify events have been enhanced by interviewing Iñupiaq elders and others practicing traditional subsistence lifestyles. They can often identify the year and process by which individual lakes drained, thereby providing greater dating precision and accuracy in assessing the causal mechanism. Indigenous knowledge has provided insights into events, landforms, and processes not previously identified or considered.

Utilization of GIS modeling in geoenvironmental studies of Qaroun Lake, El Fayoum Depression, Egypt

NASA Astrophysics Data System (ADS)

Attia, Abdelaal H.; El-Sayed, Salah Abdelwahab; El-Sabagh, Moustafa E.

2018-02-01

Qaroun Lake, the study area, is a natural protectorate located at the northern part of El Fayoum Depression, Egypt. An integrated approach including hydrochemistry, mineralogy of sediments and GIS analysis and modeling was conducted in order to determine the different geoenvironmental parameters affecting the lake environmental system. Forty two environmental water and sediment samples were collected from the lake and relevant drains in 2013. The water samples were analyzed for major ions and trace elements and the sediment ones were analyzed for clay and non-clay minerals. This study showed that the saline water of the lake (31490 < TDS < 45100 mg/l) typically is Na-Cl-SO4 water possessing primary salinity properties dominated by alkalies and strong acids. The order of ionic dominance was Na+ > Mg2+ > Ca2+ > K+ - Cl- > SO42- > HCO3- > CO32-. The water salt assemblages were KCl - NaCl - Na2SO4 - MgSO4 - CaSO4 - Ca(HCO3)2 reflecting a mixed water type. The contents of NaCl, Na2SO4 and MgSO4 salts were found to be fully controlled with the lake depths. The hydrogeochemical investigations revealed that the evaporation concentration is the primary process of the lake water evolution. The presence of trace elements in the lake water is essentially of allochtonous origin. The GIS-based maps indicated that the concentrations of Zn, Co, Mo, Pb, F and Cd elements in water had increased in the eastern part of the lake; meanwhile, the contents of NO3- ions had increased in the southwestern part indicating that these parts were the most vulnerable to the potential pollution with such elements. The XRD analysis revealed the existence of different mineral assemblages (quartz, kaolinite, goethite, calcite, halite, hematite, feldspar, gypsum, dolomite and saponite) in bottom sediments. The mineral concentrations varied greatly from place to another place along the lake and their distributions were asymmetric. The dominant minerals were the quartz and calcite. The mineralogical

Model Estimates of Pan-Arctic Lake and Wetland Methane Emissions

NASA Astrophysics Data System (ADS)

Chen, X.; Bohn, T. J.; Glagolev, M.; Maksyutov, S.; Lettenmaier, D. P.

2012-12-01

Lakes and wetlands are important sources of the greenhouse gases CO2 and CH4, whose emission rates are sensitive to climate. The northern high latitudes, which are especially susceptible to climate change, contain about 50% of the world's lakes and wetlands. With the predicted changes in the regional climate for this area within the next century, there is concern about a possible positive feedback resulting from greenhouse gas emissions (especially of methane) from the region's wetlands and lakes. To study the climate response to emissions from northern hemisphere lakes and wetlands, we have coupled a large-scale hydrology and carbon cycling model (University of Washington's Variable Infiltration Capacity model; VIC) with the atmospheric chemistry and transport model (CTM) of Japan's National Institute for Environmental Studies and have applied this modelling framework over the Pan-Arctic region. In particular, the VIC model simulates the land surface hydrology and carbon cycling across a dynamic lake-wetland continuum. The model includes a distributed wetland water table that accounts for microtopography and simulates variations in inundated area that are calibrated to match a passive microwave based inundation product. Per-unit-area carbon uptake and methane emissions have been calibrated using extensive in situ observations. In this paper, the atmospheric methane concentrations from a coupled run of VIC and CTM are calibrated and verified for the Pan-Arctic region with satellite observations from Aqua's Atmospheric Infrared Sounder (AIRS) and Envisat's Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) instruments. We examine relative emissions from lakes and wetlands, as well as their net greenhouse warming potential, over the last half-century across the Pan-Arctic domain. We also assess relative uncertainties in emissions from each of the sources.

A post-Calumet shoreline along southern Lake Michigan

USGS Publications Warehouse

Capps, D.K.; Thompson, T.A.; Booth, R.K.

2007-01-01

The southern shore of Lake Michigan is the type area for many of ancestral Lake Michigan's late Pleistocene lake phases, but coastal deposits and features of the Algonquin phase of northern Lake Michigan, Lake Huron, and Lake Superior are not recognized in the area. Isostatic rebound models suggest that Algonquin phase deposits should be 100 m or more below modern lake level. A relict shoreline, however, exists along the lakeward margin of the Calumet Beach that was erosional west of Deep River and depositional east of the river. For this post-Calumet shoreline, the elevation of basal foreshore deposits east of Deep River and the base of the scarp west of Deep River indicate a slightly westward dipping water plane that is centered at ???184 m above mean sea level. Basal foreshore elevations also indicate that lake level fell ???2 m during the development of the shoreline. The pooled mean of radiocarbon dates from the surface of the peat below post-Calumet shoreline foreshore deposits indicate that the lake transgressed over the peat at 10,560 ?? 70 years B.P. Pollen assemblages from the peat are consistent with this age. The elevation and age of the post-Calumet shoreline are similar to the Main Algonquin phase of Lake Huron. Recent isostatic rebound models do not adequately address a high-elevation Algonquin-age shoreline along the southern shore of Lake Michigan, but the Goldthwait (1908) hinge-line model does. ?? 2006 Springer Science+Business Media B.V.

Thermal processes of thermokarst lakes in the continuous permafrost zone of northern Siberia - observations and modeling (Lena River Delta, Siberia)

NASA Astrophysics Data System (ADS)

Boike, J.; Georgi, C.; Kirilin, G.; Muster, S.; Abramova, K.; Fedorova, I.; Chetverova, A.; Grigoriev, M.; Bornemann, N.; Langer, M.

2015-10-01

Thermokarst lakes are typical features of the northern permafrost ecosystems, and play an important role in the thermal exchange between atmosphere and subsurface. The objective of this study is to describe the main thermal processes of the lakes and to quantify the heat exchange with the underlying sediments. The thermal regimes of five lakes located within the continuous permafrost zone of northern Siberia (Lena River Delta) were investigated using hourly water temperature and water level records covering a 3-year period (2009-2012), together with bathymetric survey data. The lakes included thermokarst lakes located on Holocene river terraces that may be connected to Lena River water during spring flooding, and a thermokarst lake located on deposits of the Pleistocene Ice Complex. Lakes were covered by ice up to 2 m thick that persisted for more than 7 months of the year, from October until about mid-June. Lake-bottom temperatures increased at the start of the ice-covered period due to upward-directed heat flux from the underlying thawed sediment. Prior to ice break-up, solar radiation effectively warmed the water beneath the ice cover and induced convective mixing. Ice break-up started at the beginning of June and lasted until the middle or end of June. Mixing occurred within the entire water column from the start of ice break-up and continued during the ice-free periods, as confirmed by the Wedderburn numbers, a quantitative measure of the balance between wind mixing and stratification that is important for describing the biogeochemical cycles of lakes. The lake thermal regime was modeled numerically using the FLake model. The model demonstrated good agreement with observations with regard to the mean lake temperature, with a good reproduction of the summer stratification during the ice-free period, but poor agreement during the ice-covered period. Modeled sensitivity to lake depth demonstrated that lakes in this climatic zone with mean depths > 5 m develop

Strong Medieval Earthquake in the Northern Issyk-Kul Lake Region (Tien Shan): Results of Paleoseismological and Archeoseismological Studies

NASA Astrophysics Data System (ADS)

Korzhenkov, A. M.; Deev, E. V.; Luzhanskii, D. V.; Abdieva, S. V.; Agatova, A. R.; Mazeika, J. V.; Men'shikov, M. Yu.; Rogozhin, E. A.; Rodina, S. N.; Rodkin, M. V.; Sorokin, A. A.; Fortuna, A. B.; Charimov, T. A.; Shen, J.; Yudakhin, A. S.

2017-12-01

A number of archeological monuments in the northern Issyk-Kul Lake region (Tien Shan) in the basins of the Chet-Koysuu and Chon-Koysuu rivers are studied. All monuments have undergone significant seismogenic deformations and destructions. A cromlech (7th century BC to 8th centuries AD) was displaced along the sinistral strike-slip fault. A kurgan (7th-13th centuries AD) was deformed in a front of the reverse fault scarp. A fortress (14th-15th centuries AD) was submerged beneath the lake water during the catastrophic subsidence of the coastal zone. We identify a zone of the seismogenic rupture. It is located along the Kultor border fault, which separates the Issyk-Kul depression and its surrounding mountains (Kungey Ala-Too Range). During the earthquake, the seismogenic reverse fault scarp was formed. A total of 1.6 m was offset along the rupture, which corresponds to an earthquake with M S ≥ 7 and seismic intensity of I 0 ≥ IX. Judging by numerous radiocarbon datings of submerged wood, which was used in building the fortress (end of 14th to the beginning of 15th centuries AD), the earthquake occurred in the 16th century AD and could have caused the decline of the Mogul civilization in the northern Issyk-Kul Lake region.

Current threats to the Lake Texcoco globally important bird area

Treesearch

Jose L. Alcantara; Patricia Escalante Pliego

2005-01-01

Lake Texcoco was reported as almost dry in the late 1960s, and as a consequence the aquatic life has been considered gone since then. However, the government undertook a reclamation/restoration project in the area beginning in 1971 to help alleviate some of the environmental problems of Mexico City. Although Lake Texcoco was not completely dry in that period, the basin...

Coherent monsoonal changes in the northern tropics revealed by Chadian lakes (L. Chad and Yoa) sedimentary archives during the African Humid Period

NASA Astrophysics Data System (ADS)

Sylvestre, Florence; Kroepelin, Stefan; Pierre, Deschamps; Christine, Cocquyt; Nicolas, Waldmann; Kazuyo, Tachikawa; Amaral Paula, Do; Doriane, Delanghe; Guillaume, Jouve; Edouard, Bard; Camille, Bouchez; Jean-Claude, Doumnang; Jean-Charles, Mazur; Martin, Melles; Guillemette, Menot; Frauke, Rostek; Nicolas, Thouveny; Volkner, Wennrich

2016-04-01

In northern African tropics, it is now well established that the Last Glacial Maximum (LGM) was extremely dry followed by a wetter Holocene. Numerous palaeolake records reveal a fairly consistent pattern of a moister early Holocene resulting in a green Sahara followed by the onset of aridification about 4000 years ago. These palaeoenvironmental conditions are deciphered from several continental records distributed over the sub-Saharan zone and including diverse environments. However, pronounced differences in the timing and amplitude of these moisture changes inferred from sedimentary records point to both regional climatic variability change and site-specific influences of local topographic-hydrogeological factors which biased the evolution of water balance reconstructed from individual lacustrine archives. Here we present hydrological reconstructions from Chadian lakes, i.e. Lake Chad (c. 13°N) and Lake Yoa (19°N). Because of their location, both records allow to reconstruct lake level fluctuations and environmental changes according to a gradient from Sahelian to Saharan latitudes. Whereas Lake Chad is considered as a good sensor of climatic changes because of its large drainage basin covering 610,000 km2 in the Sudanian belt, Lake Yoa logs the northern precipitation changes in the Sahara. Combining sedimentological (laser diffraction grain size) and geochemical (XRF analysis) data associated with bio-indicators proxies (diatoms, pollen), we compare lake-level fluctuations and environmental changes during the last 12,000 years. After the hyperarid Last Glacial Maximum period during which dunes covered the Lake Chad basin, both lake records indicate an onset of more humid conditions between 12.5-11 ka cal BP. These resulted in lacustrine transgressions approaching their maximum extension at c. 10.5 ka cal BP. The lacustrine phase was probably interrupted by a relatively short drying event occurring around 8.2 ka cal BP which is well-defined in Lake Yoa by

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)

Progress toward lake trout restoration in Lake Michigan

USGS Publications Warehouse

Holey, Mark E.; Rybicki, Ronald W.; Eck, Gary W.; Brown, Edward H.; Marsden, J. Ellen; Lavis, Dennis S.; Toneys, Michael L.; Trudeau, Tom N.; Horrall, Ross M.

1995-01-01

hatchery. A recent increase in lamprey wounding rates in northern Lake Michigan appears to be related to the uncontrolled build-up of lampreys in the St. Marys River a tributary of Lake Huron. If left uncontrolled, further progress toward restoration in the Northern Refuge may be limited.

Lake Chad, Chad as seen from STS-66

NASA Image and Video Library

1994-11-14

This oblique view of Lake Chad was taken by the STS-66 crew in November 1994. This lake lies mainly in the Republic of Chad and partly in Nigeria, Cameroon and Niger. The size of Lake Chad varies seasonally and is actually divided into north and south basins; neither of which is generally more than 25 feet (7.6 meters) deep. In this photograph, all the water appears to be located in the southern basin with the northern and eastern edges of both basins covered with sand dunes which have invaded the area where the water once stood. The prevailing wind direction can be seen from the agriculture burning in both basins to be from the east.

Assessment of the spatial extent and height of flooding in Lake Champlain during May 2011, using satellite remote sensing and ground-based information

USGS Publications Warehouse

Bjerklie, David M.; Trombley, Thomas J.; Olson, Scott A.

2014-01-01

Landsat 5 and moderate resolution imaging spectro-radiometer satellite imagery were used to map the area of inundation of Lake Champlain, which forms part of the border between New York and Vermont, during May 2011. During this month, the lake’s water levels were record high values not observed in the previous 150 years. Lake inundation area determined from the satellite imagery is correlated with lake stage measured at three U.S. Geological Survey lake level gages to provide estimates of lake area at different lake levels (stage/area rating) and also compared with the levels of the high-water marks (HWMs) located on the Vermont side of the lake. The rating developed from the imagery shows a somewhat different relation than a similar stage/area rating developed from a medium-resolution digital elevation model (DEM) of the region. According to the rating derived from the imagery, the lake surface area during the peak lake level increased by about 17 percent above the average or “normal” lake level. By using a comparable rating developed from the DEM, the increase above average is estimated to be about 12 percent. The northern part of the lake (north of Burlington) showed the largest amount of flooding. Based on intersecting the inundation maps with the medium-resolution DEM, lake levels were not uniform around the lake. This is also evident from the lake level gage measurements and HWMs. The gage data indicate differences up to 0.5 feet between the northern and southern end of the lake. Additionally, the gage data show day-to-day and intradaily variation of the same range (0.5 foot). The high-water mark observations show differences up to 2 feet around the lake, with the highest level generally along the south- and west-facing shorelines. The data suggest that during most of May 2011, water levels were slightly higher and less variable in the northern part of the lake. These phenomena may be caused by wind effects as well as proximity to major river inputs to

36 CFR 7.62 - Lake Chelan National Recreation Area.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., and depending on local weather conditions, the superintendent may designate as open to the use of snowmobiles the following locations within the Lake Chelan National Recreation Area: (1) All open areas..., except cross-country ski trails and within the perimeter of the Buckner Orchard. Snowmobile use on open...

The community structure and seasonal dynamics of plankton in Bange Lake, northern Tibet, China

NASA Astrophysics Data System (ADS)

Zhao, Wen; Zhao, Yuanyi; Wang, Qiaohan; Zheng, Mianping; Wei, Jie; Wang, Shan

2016-11-01

The seasonal variations in biomass, abundance, and species composition of plankton in relation to hydrography were studied in the saline Bange Lake, northern Tibet, China. Sampling was carried out between one to three times per month from May 2001 to July 2002. Salinity ranged from 14 to 146. The air and water temperature exhibited a clear seasonal pattern, and mean annual temperatures were approximately 4.8°C and 7.3°C, respectively. The lowest water temperature occurred in winter from December to March at -2°C and the highest in June and July at 17.7°C. Forty-one phytoplankton taxa, 21 zooplankton, and 5 benthic or facultative zooplankton were identified. The predominant phytoplankton species were Gloeothece linearis, Oscillatoria tenuis, Gloeocapsa punctata, Ctenocladus circinnatus, Dunaliella salina, and Spirulina major. The predominant zooplankton species included Holophrya actra, Brachionus plicatilis, Daphniopsis tibetana, Cletocamptus dertersi, and Arctodiaptomus salinus. The mean annual total phytoplankton density and biomass for the entire lake were 4.52×107 cells/L and 1.60 mg/L, respectively. The annual mean zooplankton abundance was 52, 162, 322, and 57, 144 ind./L, in the three sublakes. The annual mean total zooplankton biomass in Lakes 1-3 was 1.23, 9.98, and 2.13 mg/L, respectively. The annual mean tychoplankton abundances in Bg1, 2, and 3 were 47, 67, and 654 ind./L. The annual mean tychoplankton biomass was 2.36, 0.16, and 2.03 mg/L, respectively. The zooplankton biomass (including tychoplankton) in the lake was 9.11 mg/L. The total number of plankton species in the salt lake was significantly negatively correlated with salinity.

Spatial and temporal variation in distribution of larval lake whitefish in eastern Lake Ontario: signs of recovery?

USGS Publications Warehouse

McKenna, J.E.; Johnson, J. H.

2009-01-01

The lake whitefish (Coregonus clupeaformis) is one of the native Lake Ontario fishes that declined severely over the past century. Recent evidence of larval lake whitefish production in a historic spawning area (Chaumont Bay) might signal a recovery of this species in New York waters. We surveyed coastal and open water areas to evaluate densities and estimate total abundance of larval lake whitefish in Chaumont Bay. Other historic spawning areas and embayments with appropriate spawning and nursery habitat were also surveyed, but only a few larvae were found outside of Chaumont Bay. Lake whitefish larvae were found in every embayment sampled within Chaumont Bay, with larval densities of nearly 600/1000 m2 in some samples. Greatest abundances occurred in the northern sectors and near the mouth of the bay. Open water densities were generally less than half that of nearshore sites. The total bay-wide estimate for 2005 was approximately 644,000 lake whitefish larvae, but dropped to 230,000–400,000 in 2006 and 2007, respectively. Mean larval growth rates (0.36 mm/day) did not differ by year, but were consistently higher in early May than in late April. Lake whitefish production in Chaumont Bay is encouraging for this species, but the cause and persistence of the decline after 2005 can be determined only by continued monitoring. Other possible bottlenecks of survival may exist at juvenile and adult stages and could significantly affect recruitment dynamics. This species is sensitive to normal climatic fluctuations and increased variability associated with global climatic change could make winter nursery conditions unfavorable for this species.

36 CFR 7.57 - Lake Meredith National Recreation Area.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Lake Meredith National Recreation Area. 7.57 Section 7.57 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF.... (iv) PWC may not operate at greater than flat wake speed in the following designated areas: North...

36 CFR 7.57 - Lake Meredith National Recreation Area.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Lake Meredith National Recreation Area. 7.57 Section 7.57 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF.... (iv) PWC may not operate at greater than flat wake speed in the following designated areas: North...

36 CFR 7.57 - Lake Meredith 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 Meredith National Recreation Area. 7.57 Section 7.57 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF.... (iv) PWC may not operate at greater than flat wake speed in the following designated areas: North...

36 CFR 7.57 - Lake Meredith National Recreation Area.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Lake Meredith National Recreation Area. 7.57 Section 7.57 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF.... (iv) PWC may not operate at greater than flat wake speed in the following designated areas: North...

36 CFR 7.57 - Lake Meredith 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 Meredith National Recreation Area. 7.57 Section 7.57 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF.... (iv) PWC may not operate at greater than flat wake speed in the following designated areas: North...

Looking Down on Lakes

NASA Image and Video Library

2014-04-07

NASA Cassini spacecraft peers down though layers of haze to glimpse the lakes of Titan northern regions. Titan has a hydrological cycle similar to Earth, but instead of water, Titan lakes and seas are filled with liquid methane and ethane.

Do water level fluctuations influence production of walleye and yellow perch young-of-the-year in large northern lakes?

USGS Publications Warehouse

Larson, James H.; Staples, David F.; Maki, Ryan P.; Vallazza, Jon M.; Knights, Brent C.; Peterson, Kevin E.

2016-01-01

Many ecological processes depend on the regular rise and fall of water levels (WLs), and artificial manipulations to WL regimes can impair important ecosystem services. Previous research has suggested that differences in WL between late summer and early spring may alter the suitability of shoals used by Walleyes Sander vitreus for spawning. Other species, such as the Yellow Perch Perca flavescens, are unlikely to be affected in the same way by WL fluctuations because their spawning requirements are quite different. We used 11–23 years of data from six northern Minnesota lakes to assess the effects of WL fluctuations on the abundances of young-of-the-year (age-0) Walleyes and Yellow Perch. In two lakes (Rainy Lake and Lake Kabetogama), a change in WL management occurred in 2000, after which these lakes saw increased age-0 Walleye abundance, while the other study lakes experienced decreases or no change. Rainy Lake and Lake Kabetogama also had increases in age-0 Yellow Perch, but another study lake did also. We used partial least-squares regression to assess whether WL metrics were associated with variation in age-0 Walleye and Yellow Perch abundances, but WL metrics were seldom associated with age-0 abundance for either species. Our analysis suggested a potential influence of WL regulation on age-0 Walleye abundance, but we found no evidence that early spring access to spawning shoals was the mechanism by which this occurred.

Growth, condition, diet, and consumption rates of northern pike in three Arizona reservoirs

USGS Publications Warehouse

Flinders, J.M.; Bonar, Scott A.

2008-01-01

Northern pike (Esox lucius L.) introductions are controversial in the western United States due to suspected impacts they might have on established sport fisheries and potential illegal introductions. Tbree Arizona reservoirs, Parker Canyon Lake, Upper Lake Mary and Long Lake were sampled to examine the diet, consumption dynamics, and growth of northern pike. Northern pike diets varied by season and reservoir. In Parker Canyon Lake, diets were dominated by rainbow trout in winter and spring and bluegill and green sunfish in the fall. In Long Lake the northern pike ate crayfish in spring and early summer and switched to young of the year common carp in summer and fall. Black crappie, golden shiners, and crayfish were the major prey in Upper Lake Mary during spring, but they switched to stocked rainbow trout in the fall. Northern pike growth was in the high range of growth reported throughout the United States. Estimated northern pike specific consumption rate (scr) of rainbow trout (g/g/d ?? 10-6) was greatest in Upper Lake Mary (scr = 329.1 ?? 23.7 g/g/d ?? 10-6) where stocked fingerling (280 mm TL) rainbow trout stocked in Long Lake (scr = 1.4 ?? 0.1 g/g/d ?? 10-6) and Parker Canyon Lake (scr = 287.2 ?? 15.1 g/g/d ?? 10-6) where catchable-sized rainbow trout were stocked. Managers should consider the cost-benefits of stocking fish >200 mm TL in lakes containing northern pike. ?? Copyright by the North American Lake Management Society 2008.

Permafrost investigations at the Lake Hövsgöl, northern Mongolia, using DC resistivity tomography and DEM-analyses

NASA Astrophysics Data System (ADS)

Etzelmuller, B.; Heggem, E. S. F.; Frauenfelder, R.; Romanovsky, V.; Sharkhuu, N.; Jambaljav, Y.; Tumensetseg, S.; Kääb, A.; Goulden, C.

2003-04-01

The region of Lake Hövsgöl, northern Mongolia, lies at the southern edge of Siberia and forms the southern-most fringe of the Siberian continuous permafrost zone. Analysis of long-term temperature data from the area indicates that annual temperatures have warmed by about 1.5^oC over the last 40 years. Being at the southern fringe of permafrost existence, temperature changes are supposed to have a major impact on permafrost degradation and thus on the environment, in interaction with human activities like nomadic pasture use. The objective of this study is to define the distribution of permafrost and the depth of the active zones in detail, and to begin a monitoring program of soil and permafrost temperatures in the study area. During these studies (a) field measurements of ground temperature, (b) analyses of geophysical parameters (mainly ground resistivities), and (c) the generation and analyses of digital elevation models and satellite imagery were carried out. The field measurements provided the basis for the later development of statistical/empirical and physical models of the permafrost distribution in the Hövsgöl area. This presentation will focus on the DC-resistivity tomography mapping of permafrost and digital elevation model analyses. The study showed that DC resistivity tomography was useful to distinguish the active layer and permafrost thickness under different types of surface cover. The project is funded by a five-year grant from the Global Environment Facility to the Mongolian Academy of Sciences (MAS), implemented by the World Bank and a foundation of the Mongolian Long Term Ecological Research Program at Lake Hövsgöl.

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

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.

Photo Gallery for Lake Pontchartrain Area/New Orleans (Louisiana)

EPA Pesticide Factsheets

Lake Pontchartrain Area/New Orleans (Louisiana) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating with community-led efforts.

Program Contacts for Lake Pontchartrain Area/New Orleans (Louisiana)

EPA Pesticide Factsheets

Lake Pontchartrain Area/New Orleans (Louisiana) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating with community-led efforts

Links Related to Lake Pontchartrain Area/New Orleans (Louisiana)

EPA Pesticide Factsheets

Lake Pontchartrain Area/New Orleans (Louisiana) of the Urban Waters Federal Partnership (UWFP) reconnects urban communities with their waterways by improving coordination among federal agencies and collaborating with community-led efforts

36 CFR 7.55 - Lake Roosevelt National Recreation Area.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Lake Roosevelt National Recreation Area. 7.55 Section 7.55 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF... except in designated swimming areas. (4) PWC may not be operated at greater than flat-wake speeds in the...

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 Recreation Area. 7.55 Section 7.55 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF... except in designated swimming areas. (4) PWC may not be operated at greater than flat-wake speeds in the...

36 CFR 7.55 - Lake Roosevelt National Recreation Area.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Lake Roosevelt National Recreation Area. 7.55 Section 7.55 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF... except in designated swimming areas. (4) PWC may not be operated at greater than flat-wake speeds in the...

36 CFR 7.55 - Lake Roosevelt National Recreation Area.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Lake Roosevelt National Recreation Area. 7.55 Section 7.55 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF... except in designated swimming areas. (4) PWC may not be operated at greater than flat-wake speeds in the...

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 Recreation Area. 7.55 Section 7.55 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF... except in designated swimming areas. (4) PWC may not be operated at greater than flat-wake speeds in the...

Lake Baikal, Russia as seen by STS-60

NASA Technical Reports Server (NTRS)

1994-01-01

Lake Baikal, in southeastern Siberia, is the largest freshwater lake in the world. This view shows the northern end of the lake, and was taken in the early morning with low sun highlighting the mountain ranges rimming the lake basin. Pristine forests surround the lake.

Northern protected areas will become important refuges for biodiversity tracking suitable climates.

PubMed

Berteaux, Dominique; Ricard, Marylène; St-Laurent, Martin-Hugues; Casajus, Nicolas; Périé, Catherine; Beauregard, Frieda; de Blois, Sylvie

2018-03-15

The Northern Biodiversity Paradox predicts that, despite its globally negative effects on biodiversity, climate change will increase biodiversity in northern regions where many species are limited by low temperatures. We assessed the potential impacts of climate change on the biodiversity of a northern network of 1,749 protected areas spread over >600,000 km 2 in Quebec, Canada. Using ecological niche modeling, we calculated potential changes in the probability of occurrence of 529 species to evaluate the potential impacts of climate change on (1) species gain, loss, turnover, and richness in protected areas, (2) representativity of protected areas, and (3) extent of species ranges located in protected areas. We predict a major species turnover over time, with 49% of total protected land area potentially experiencing a species turnover >80%. We also predict increases in regional species richness, representativity of protected areas, and species protection provided by protected areas. Although we did not model the likelihood of species colonising habitats that become suitable as a result of climate change, northern protected areas should ultimately become important refuges for species tracking climate northward. This is the first study to examine in such details the potential effects of climate change on a northern protected area network.

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. Copyright © 2012 Elsevier B.V. All rights reserved.

Impacts of urban sprawl on the area of downtown lakes in a highly developing city on central China

NASA Astrophysics Data System (ADS)

Zhang, W.; Zhang, Y.

2016-12-01

Wuhan city in central China is full of water resources and numerous lakes are located. Downtown lakes have significant ecological value and ornamental value for urban inhabitants in Wuhan. Under the rapid process of urban sprawl, downtown lakes are occupied by impervious areas. This research uses Landsat images to extract land uses from 1991 to 2013 in Wuhan city , and attempts to find out how urban sprawl affects the water body area decline in space. Two largest downtown lakes in Wuhan city, Donghu Lake located in central city and Tangxunhu Lake located in suburbs, are taken as case study area. A direction change index (DCI) is proposed to evaluate the changes of a specific land use in different directions. The results reveal that two downtown lakes are undergoing rapid water body area decline from 1991 to 2013, with decline rate are -0.022 in Donghu watershed and -0.011 in Tangxunhu watershed. 68.26% and 62.50% of the reduced water body is occupied by built-up land in Donghu watershed and Tangxunhu watershed, respectively. According to DCI, the water body reduce is highly correlated with built-up land increase in all direction. Moreover, it is found that in the Donghu watershed the north-west part suffered significant water body area decline, which is close to central city. While in Tangxunhu watershed, the area of water body declined in north-west, south-west and north-east part, and the area obstructed from central city by the lake was suffering less water body area decline. It is concluded that the water body area of downtown lakes are highly affected by the process of urban sprawl, and the lakes in central districts trends to suffer higher descend than that of the downtown lake located in suburbs. Meanwhile, even for the same downtown lake, the area orientating and close to the central city may suffer more rapid decline than the area that does not orientate to the central city.

Decadal and Seasonal Variations of Alpine Lakes in Glacierized areas of Central Asia during 1990-2015

NASA Astrophysics Data System (ADS)

Li, J.; Warner, T.; Chen, X.; Bao, A.

2016-12-01

Central Asia is one of the world's most vulnerable areas responding to global change. Glacier lakes in the alpine regions remain sensitive to climatic change and fluctuate with temperature and precipitation variations. Study shows that glaciers in Central Asia have retreated dramatically, leading to the expansion of the existing glacial lakes and the emergence of many new glacier lakes. The existence of these lakes increases the possibility of outburst flood during the ice melting season, which can bring a disaster to the downstream area. Mapping glacial lakes and monitoring their changes would improve our understanding of regional climate change and glacier-related hazards. Glacial lakes in Central Asia are mainly located at the Tianshan Mountains, the Altai Mountains, the Kunlun Mountains and the Pamirs with average elevation more than 1500 meters. Most of these lakes are supplied with the glaciers or snowmelt water during the summer seasons. Satellite remote sensing provides an efficient and objective tool to analyze the status and variations of glacial lakes. The increased availability of remote sensing sensors with appropriate spatial and temporal resolutions, broad coverage makes lake investigations more feasible and cost-effective. The paper intends to map glacier lake changes in glacierized alpine mountains with Landsat TM/ETM+ imagery. More than 600 scenes of Landsat images in circa 1990, circa 2000, circa 2010 and circa 2015 are used to map the decadal glacial lake changes over the Central Asia, and about 8 expanding glacial lakes are selected to map seasonal changes. Over 12000 glacial lakes were mapped in circa 1990, and in 2015, lake number are more than 16000, most of these new lakes are emerging in the last 10 years. The result shows that the number and area of the glacial lakes in the Altain Mountain remain stable, while the Tianshan Mountain have experienced expanding changes in the last two decades, and about a half number of lake areas are

Drainage areas in the Vermillion River basin in eastern South Dakota

USGS Publications Warehouse

Benson, Rick D.; Freese, M.D.; Amundson, Frank D.

1988-01-01

Above-normal precipitation in the northern portion of the Vermillion River basin from 1982 through 1987 caused substantial rises in lake levels in the Lake Thompson chain of lakes, resulting in discharge from Lake Thompson to the East Fork Vermillion River. Prior to 1986, the Lake Thompson chain of lakes was thought to be a noncontributing portion of the Vermillion River basin. To better understand surface drainage, the map delineates all named stream basins, and all unnamed basins larger than approximately 10 sq mi within the Vermillion River basin in South Dakota and lists by stream name the area of each basin. Stream drainage basins were delineated by visual interpretation of contour information of U.S. Geological Survey 7 1/2 minute topographic maps. Two tables list areas of drainage basins and reaches, as well as drainage areas above gaging stations. (USGS)

Integrating limnological characteristics of high mountain lakes into the landscape of a natural area

USGS Publications Warehouse

Larson, Gary L.; Wones, A.; McIntire, C.D.; Samora, B.

1994-01-01

A general conceptual watershed-lake model of the complex interactions among climatic conditions, watershed location and characteristics, lake morphology, and fish predation was used to evaluate limnological characteristics of high mountain lakes. Our main hypothesis was that decreasing elevation in mountainous terrain corresponds to an increase in diversity of watershed size and lake area, depth, temperature, nutrient concentrations, and productivity. A second hypothesis was that watershed location and aspect relative to climatic gradients within mountainous terrain influences the limnological characteristics of the lakes. We evaluated these hypotheses by examining watershed location, aspect and size; lake morphology; water quality; and phytoplankton and zooplankton community characteristics among high mountain forest and subalpine lakes in Mount Rainier National Park. Although many of the comparisons between all forest and subalpine lakes were statistically insignificant, the results revealed trends that were consistent with our hypotheses. The forest lake group included more lakes with larger watersheds, larger surface areas, greater depths, higher concentrations of nutrients, and higher algal biovolumes than did the group of subalpine lakes. Deep lakes, which were mostly of the forest lake type, exhibited thermal stratification and relatively high values of some of the water-quality variables near the lake bottoms. However, the highest near-surface water temperatures and phytoplankton densities and the taxonomic structures of the phytoplankton and zooplankton assemblages were more closely related to geographical location, which corresponded to a west-east climate gradient in the park, than to lake type. Some crustacean and rotifer taxa, however, were limited in distribution by lake type. Fish predation did not appear to play an important role in the structure of the crustacean zooplankton communities at the genus level with the exception of Mowich Lake, where

The flora of the Cottonwood Lake Study Area, Stutsman County, North Dakota

USGS Publications Warehouse

Mushet, D.M.; Euliss, N.H.; Lane, S.P.; Goldade, C.M.

2004-01-01

The 92 ha Cottonwood Lake Study Area is located in south-central North Dakota along the eastern edge of a glacial stagnation moraine known as the Missouri Coteau. The study area has been the focus of biologic and hydrologic research since the U.S. Fish and Wildlife Service purchased the site in 1963. We studied the plant communities of the Cottonwood Lake Study Area from 1992 to 2001. During this time period, the vascular flora of the study area consisted of 220 species representing 51 families. Over half of the species were perennial forbs (117 species). Perennial grasses (26 species) and annual forbs (22 species) made up the next two largest physiognomic groupings. The flora, having a mean Coefficient of Conservatism of 4.6 and a Floristic Quality Index of 62, consisted of 187 native species. Thirty-three species were non-natives. Our annotated list should provide information useful to researchers, graduate students, and others as they design and implement future studies in wetlands and uplands both in and around the Cottonwood Lake Study Area.

A coupled lake-atmosphere model (CLAM) and its application to Lake Kinneret

NASA Astrophysics Data System (ADS)

Pan, Hai

1999-08-01

Kinneret is a 166-km2 lake located in Northern Israel, in the central part of the Jordan Valley, a corridor running from north to south, between the Galilee hills in the west and the Golan Heights in the east. Both the Galilee hills and the Golan Heights reach an elevation of about 400 m above mean sea level (MSL), and the lake is about -210 m (MSL). North of the lake is the mountainous area of the Hermon, culminating at about 2800 m (MSL). About 120 km south of it is the Dead Sea, which is about -410 m (MSL), and about 45 km west of it is the Mediterranean Sea. The complexity of the terrain, combined with relatively arid soil and various ground covers surrounding the lake, results in a very complicated system of atmospheric and lake processes. To understand this system, especially the processes affecting the atmosphere and lake dynamics and thermodynamics, and their effects on Lake Kinneret evaporation, a coupled lake-atmosphere model (CLAM) was developed and applied to the lake region. The CLAM is based on the Regional Atmospheric Modeling System (RAMS) and the oceanic S-coordinate Rutgers University Model (SCRUM). Energy, mass, and momentum are conserved at the interface between the atmosphere and the lake, and appropriate balance equations are applied there. In the atmospheric module, two nested grids are employed to simulate Northern Israel at a resolution of 4 x 4 km2, and the near-lake region at a resolution of 1 x 1 km 2. Synoptic conditions obtained from the National Meteorological Center (NMC) reanalysis are assimilated by the model. Soil moisture, which appears to have a significant impact on atmospheric circulation in this region, was transformed from the normalized difference vegetation index (NDVI). Observations collected during two summers above and inside the lake emphasize the good capability of CLAM to simulate surface fluxes and other microclimatic conditions, as well as lake temperature and currents. Although the lake is small (about 12-km wide

Comparing Physics Scheme Performance for a Lake Effect Snowfall Event in Northern Lower Michigan

NASA Technical Reports Server (NTRS)

Molthan, Andrew; Arnott, Justin M.

2012-01-01

High resolution forecast models, such as those used to predict severe convective storms, can also be applied to predictions of lake effect snowfall. A high resolution WRF model forecast model is provided to support operations at NWS WFO Gaylord, Michigan, using a 12 ]km and 4 ]km nested configuration. This is comparable to the simulations performed by other NWS WFOs adjacent to the Great Lakes, including offices in the NWS Eastern Region who participate in regional ensemble efforts. Ensemble efforts require diversity in initial conditions and physics configurations to emulate the plausible range of events in order to ascertain the likelihood of different forecast scenarios. In addition to providing probabilistic guidance, individual members can be evaluated to determine whether they appear to be biased in some way, or to better understand how certain physics configurations may impact the resulting forecast. On January 20 ]21, 2011, a lake effect snow event occurred in Northern Lower Michigan, with cooperative observing and CoCoRaHS stations reporting new snow accumulations between 2 and 8 inches and liquid equivalents of 0.1 ]0.25 h. The event of January 21, 2011 was particularly well observed, with numerous surface reports available. It was also well represented by the WRF configuration operated at NWS Gaylord. Given that the default configuration produced a reasonable prediction, it is used here to evaluate the impacts of other physics configurations on the resulting prediction of the primary lake effect band and resulting QPF. Emphasis here is on differences in planetary boundary layer and cloud microphysics parameterizations, given their likely role in determining the evolution of shallow convection and precipitation processes. Results from an ensemble of seven microphysics schemes and three planetary boundary layer schemes are presented to demonstrate variability in forecast evolution, with results used in an attempt to improve the forecasts in the 2011 ]2012

Sensitivity analysis of lake mass balance in discontinuous permafrost: the example of disappearing Twelvemile Lake, Yukon Flats, Alaska (USA)

USGS Publications Warehouse

Jepsen, S.M.; Voss, C.I.; Walvoord, Michelle Ann; Rose, J.R.; Minsley, B.J.; Smith, B.D.

2013-01-01

Many lakes in northern high latitudes have undergone substantial changes in surface area over the last four decades, possibly as a result of climate warming. In the discontinuous permafrost of Yukon Flats, interior Alaska (USA), these changes have been non-uniform across adjacent watersheds, suggesting local controls on lake water budgets. Mechanisms that could explain the decreasing mass of one lake in Yukon Flats since the early 1980s, Twelvemile Lake, are identified via a scoping analysis that considers plausible changes in snowmelt mass and infiltration, permafrost distribution, and climate warming. Because predicted changes in evaporation (2 cmyr-1) are inadequate to explain the observed 17.5 cmyr-1 reduction in mass balance, other mechanisms are required. The most important potential mechanisms are found to involve: (1) changes in shallow, lateral groundwater flow to the lake possibly facilitated by vertical freeze-thaw migration of the permafrost table in gravel; (2) increased loss of lake water as downward groundwater flow through an open talik to a permeable subpermafrost flowpath; and (3) reduced snow meltwater inputs due to decreased snowpack mass and increased infiltration of snowmelt into, and subsequent evaporation from, fine-grained sediment mantling the permafrost-free lake basin.

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.

Monitoring the lake area changes of the Qinghai-Tibet Plateau using coarse-resolution time series remote sensing data

NASA Astrophysics Data System (ADS)

Ma, M.

2015-12-01

The Qinghai-Tibet Plateau (QTP) is the world's highest and largest plateau and is occasionally referred to as "the roof of the world". As the important "water tower", there are 1,091 lakes of more than 1.0 km2 in the QTP areas, which account for 49.4% of the total area of lakes in China. Some studies focus on the lake area changes of the QTP areas, which mainly use the middle-resolution remote sensing data (e.g. Landsat TM). In this study, the coarse-resolution time series remote sensing data, MODIS data at a spatial resolution of 250m, was used to monitor the lake area changes of the QTP areas during the last 15 years. The dataset is the MOD13Q1 and the Normal Difference Vegetation Index (NDVI) is used to identify the lake area when the NDVI is less than 0. The results show the obvious inner-annual changes of most of the lakes. Therefore the annually average and maximum lake areas are calculated based on the time series remote data, which can better quantify the change characteristics than the single scene of image data from the middle-resolution data. The results indicate that there are big spatial variances of the lake area changes in the QTB. The natural driving factors are analyzed for revealing the causes of changes.

50 CFR Table 43 to Part 679 - Northern Bering Sea Research Area

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Northern Bering Sea Research Area 43... ALASKA Pt. 679, Table 43 Table 43 to Part 679—Northern Bering Sea Research Area Longitude Latitude 168 7... and Bering Seas, Area 400 and Area 514, respectively. [75 FR 61652, Oct. 6, 2010] ...

50 CFR Table 43 to Part 679 - Northern Bering Sea Research Area

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Northern Bering Sea Research Area 43... ALASKA Pt. 679, Table 43 Table 43 to Part 679—Northern Bering Sea Research Area Longitude Latitude 168 7... and Bering Seas, Area 400 and Area 514, respectively. [75 FR 61652, Oct. 6, 2010] ...

50 CFR Table 43 to Part 679 - Northern Bering Sea Research Area

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Northern Bering Sea Research Area 43... ALASKA Pt. 679, Table 43 Table 43 to Part 679—Northern Bering Sea Research Area Longitude Latitude 168 7... and Bering Seas, Area 400 and Area 514, respectively. [75 FR 61652, Oct. 6, 2010] ...

50 CFR Table 43 to Part 679 - Northern Bering Sea Research Area

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Northern Bering Sea Research Area 43... ALASKA Pt. 679, Table 43 Table 43 to Part 679—Northern Bering Sea Research Area Longitude Latitude 168 7... and Bering Seas, Area 400 and Area 514, respectively. [75 FR 61652, Oct. 6, 2010] ...

Lake Mead, NV

NASA Technical Reports Server (NTRS)

1982-01-01

Lake Mead, Nevada, (36.0N, 114.5E) where the water from the Colorado River empties after it's 273 mile journey through the Grand Canyon of Arizona is the subject of this photo. Other features of interest are Hoover Dam on the south shore of Lake Mead where cheap hydroelectric power is secondary to the water resources made available in this northern desert region and the resort city of Las Vegas, just to the west of Lake Mead.

High resolution analysis of northern Patagonia lake sediments

NASA Astrophysics Data System (ADS)

Jarvis, S. W.; Croudace, I. W.; Langdon, P. G.; Rindby, A.

2009-04-01

Sediment cores covering the period from the last glacial maximum through the Holocene to the present have been collected from sites in the Chacubuco valley, southern Chile (around 47°08'S, 72°25'W, to the east of the North Patagonian Icecap). Cores were taken from five lakes and one recently dried lake bed. Short cores (0.2 to 0.5m), covering approximately the last two hundred years, were taken from all the lakes. Additionally, long sequences were obtained from one of the lakes and from the dried lake bed, the latter sequence extending back to the last glacial maximum as indicated by thick clay at the base. Each of the lakes are small-medium sized and are open systems situated at 300-1000m above sea level. The shorter cores comprise predominantly clastic gyttja but show a number of distinct changes in colour and chemical composition that suggest major environmental changes over the period of sediment accumulation. This is also reflected in variations in the loss on ignition of samples from the cores and in elemental profiles produced by scanning the cores with the Itrax micro-XRF corescanner at 200μm resolution. The long sequence from the dried lake bed has very low organic content glacial clay at the base, interpreted as last glacial maximum basal clay following determination in the field that this layer exceeded 2m in thickness. Similar sediments occur within a stratigraphically discrete section of approximately 14cm and may relate to a stadial event. The latter section also shows a drop in organic content and appears to be glacial clay incorporating some coarse sandy components indicative of detrital input from the catchment. The second long sequence, from a carbonate lake, includes two mineral layers indicating increased detrital input from the catchment. The deeper and thicker of these layers appears similar to the 14cm layer in the first long sequence, while the upper layer comprises a fine grain size indicative of rock flour and hence also of glacial

Multi-proxy evidence for climate-driven changes in arctic lakes from northern Russia over the Holocene.

NASA Astrophysics Data System (ADS)

Self, Angela; Brooks, Stephen; Jones, Vivienne; Solovieva, Nadia; McGowan, Suzanne; Rosén, Peter; Parrott, Emily; Seppä, Heikki; Salonen, Sakari

2010-05-01

Average arctic temperatures have increased at almost twice the rate of the rest of the world over the last 100 years and climate projections suggest this trend is likely to continue resulting in an additional warming of 2 - 3°C in annual mean air temperatures by 2050. Freshwater ecosystems occupy a substantial area of the terrestrial environment in the Arctic and are particularly sensitive to temperature increases which may lead to profound changes in catchment characteristics, permafrost, hydrology and nutrient availability. Therefore it is important to understand how past changes in climate have affected these ecosystems. In this paper we present one of the first quantitative multi-proxy climate records from arctic Siberia. The affect of early - mid Holocene and recent climate change on arctic lakes in northern Russia were investigated in multi-proxy studies. The past climate was reconstructed using chironomid inference models to estimate mean July air temperatures and trends in continentality. Stable isotopes and LOI were analysed to infer past changes in sediment organic matter. Near-infrared spectroscopy (NIRS) and/or diatoms were used to infer changes in lake water total organic carbon and algal pigments and/or diatoms were used to infer changes in productivity and light penetration in the lake. Analyses of a sediment core from a tundra lake (Lake Kharinei) in north-eastern European Russia show significant assemblage changes in diatoms, chironomids and pigments, which coincide with climate-driven vegetation shifts from open birch forest to spruce forest and then to tundra over the Holocene. During the open birch phase of the late Glacial - early Holocene, chironomid-inferred reconstructions suggest that the climate was approximately 1 - 3°C warmer and more continental than present. Isotopic analyses indicate a productive environment receiving a significant input of organic material from terrestrial plants into the lake. Both diatoms and NIRS-TOC also

Influences of climate change on area variation of Qinghai Lake on Qinghai-Tibetan Plateau since 1980s.

PubMed

Tang, Lingyi; Duan, Xiaofang; Kong, Fanjin; Zhang, Fan; Zheng, Yangfan; Li, Zhen; Mei, Yi; Zhao, Yanwen; Hu, Shuijin

2018-05-09

Qinghai-Tibetan Plateau is the most sensitive region to global warming on Earth. Qinghai Lake, the largest lake on the plateau, has experienced evident area variation during the past several decades. To quantify the area changes of Qinghai Lake, a satellite-based survey based on Landsat images from the 1980s to 2010s has been performed. In addition, meteorological data from all the seven available stations on Qinghai-Tibetan Plateau has been analyzed. Area of Qinghai Lake shrank ~2% during 1987-2005, and then increased ~3% from 2005-2016. Meanwhile, the average annual temperature increased 0.319 °C/10 y in the past 50 years, where the value is 0.415 °C/10 y from 2005-2016. The structural equation modeling (SEM) shows that precipitation is the primary factor influencing the area of Qinghai Lake. Moreover, temperature might be tightly correlated with precipitation, snow line, and evaporation, thereby indirectly causes alternations of the lake area. This study elucidated the significant area variation of water body on the Qinghai-Tibetan Plateau under global warming since 1980s.

Archaeological Investigations in the Gainesville Lake Area of the Tennessee-Tombigbee Waterway. Volume II. Gainesville Lake Area Ceramic Description and Chronology.

DTIC Science & Technology

1981-10-01

D- A126 469 RCH EOLOGICAL INVESTIO TIONS IN THE G INESVILLE L KE /5 AREA OF THE TENNESS..(U) ALABAMA UNIV UNIVERSITY OFFICE S OF ARCHAEOLOGICAL...Entered) "._".__ _ _ _ REPORT DOCUMENTATION PAGE READ ISTRUCTIONSBEFORE COMPLETING FORM 1. REPORT NUMBER 2. GOVT ACCESSION NO. S . RECIPIENT’$ CATALOG...Archaeological Investi- Final May 1976-October 1981 gations in the Gainesville Lake Area of the S . PERFORMING ORG. REPORT NUMBER Tennessee-Tombigbee Waterway 7

Consumptive Water-Use Coefficients for the Great Lakes Basin and Climatically Similar Areas

USGS Publications Warehouse

Shaffer, Kimberly H.; Runkle, Donna L.

2007-01-01

Consumptive water use is the portion of water withdrawn (for a particular use) that is evaporated, transpired, incorporated into products or crops, consumed by humans or livestock, or otherwise removed from the immediate water environment. This report, which is organized by water?use categories, includes consumptive?use coefficients for the Great Lakes Basin (including Canada) and for areas climatically similar to the Great Lakes Basin. This report also contains an annotated bibliography of consumptive water?use coefficients. Selected references are listed for consumptive?use data from elsewhere in the world. For the industrial water?use category, the median consumptive?use coefficients were 10 percent for the Great Lakes Basin, climatically similar areas, and the world; the 25th and 75th percentiles for these geographic areas were comparable within 6 percent. The combined domestic and public?supply consumptive?use statistics (median, 25th and 75th percentiles) were between 10 to 20 percent for the various geographic areas. Although summary statistics were similar for coefficients in the livestock and irrigation water?use categories for the Great Lakes Basin and climatically similar areas, statistic values for the world on a whole were substantially lower (15 to 28 percent lower). Commercial and thermoelectric power consumptive?use coefficient statistics (median, 25th, and 75th percentile) also were comparable for the Great Lakes Basin and climatically similar areas, within 2 percent. References for other countries were not found for commercial and thermoelectric power water?use categories. The summary statistics for the mining consumptive?use coefficients varied, likely because of differences in types of mining, processes, or equipment.

Construction, Geologic, and Hydrologic Data for Observation Wells in the Reelfoot Lake Area, Tennessee and Kentucky

DTIC Science & Technology

1987-01-01

AND HYDROLOGIC DATA FOR OBSERVATION WELLS IN THE REELFOOT LAKE AREA, TENNESSEE AND KENTUCKY ($3 1 .cz Prepared in cooperation with the...Observation Wells in The Reelfoot Lake Area, Tennessee and Kentucky 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...Prescribed by ANSI Std Z39-18 CONSTRUCTION, GEOLOGIC, AND HYDROLOGIC DATA FOR OBSERVATION WELLS IN THE REELFOOT LAKE AREA, TENNESSEE AND KENTUCKY Michael

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.

Composition and seasonal phenology of a nonindigenous root-feeding weevil (Coleoptera: Curculionidae) complex in northern hardwood forests in the Great Lakes Region

Treesearch

R. A. Pinski; W. J. Mattson; K. F. Raffa

2005-01-01

Phyllobius oblongus (L.), Polydrusus sericeus (Schaller), and Sciaphilus asperatus (Bonsdorff) comprise a complex of nonindigenous root-feeding weevils in northern hardwood forests of the Great Lakes region. Little is known about their detailed biology, seasonality, relative abundance, and distribution patterns....

SCOPSCO: Scientific Collaboration On Past Speciation Conditions in Lake Ohrid

NASA Astrophysics Data System (ADS)

Wagner, B.; Wilke, T.; Grazhdani, A.; Kostoski, G.; Krastel-Gudegast, S.; Reicherter, K.; Zanchetta, G.

2009-04-01

Lake Ohrid is a transboundary lake with approximately two thirds of its surface area belonging to the Former Yugoslav Republic of Macedonia and about one third belonging to the Republic of Albania. With more than 210 endemic species described, the lake is a unique aquatic ecosystem and a hotspot of biodiversity. This importance was emphasized, when the lake was declared a UNESCO World Heritage Site in 1979, and included as a target area of the International Continental Scientific Drilling Program (ICDP) already in 1993. Though the lake is considered to be the oldest, continuously existing lake in Europe, the age and the origin of Lake Ohrid are not completely unravelled to date. Age estimations vary between one and ten million years and concentrate around two to five million years, and both marine and limnic origin is proposed. Extant sedimentary records from Lake Ohrid cover the last glacial/interglacial cycle and reveal that Lake Ohrid is a valuable archive of volcanic ash dispersal and climate change in the central northern Mediterranean region. These records, however, are too short to provide information about the age and origin of the lake and to unravel the mechanisms controlling the evolutionary development leading to the extraordinary high degree of endemism. Concurrent genetic brakes in several invertebrate groups indicate that major geological and/or environmental events must have shaped the evolutionary history of endemic faunal elements in Lake Ohrid. High-resolution hydroacoustic profiles (INNOMAR SES-96 light and INNOMAR SES-2000 compact) taken between 2004 and 2008, and multichannel seismic (Mini-GI-Gun) studies in 2007 and 2008 demonstrate well the interplay between sedimentation and active tectonics and impressively prove the potential of Lake Ohrid for an ICDP drilling campaign. The maximal sediment thickness is ~680 m in the central basin, where unconformities or erosional features are absent. Thus the complete history of the lake is likely

[Ecological risk assessment of Taihu Lake basin based on landscape pattern].

PubMed

Xie, Xiao Ping; Chen, Zhi Cong; Wang, Fang; Bai, Mao Wei; Xu, Wen Yang

2017-10-01

Taihu Lake basin was selected as the study site. Based on the landscape data of 2000, 2005, 2010 and 2015, the Markov and CLUE-S models were used to simulate the landscape types with different scenarios in 2030, and landscape ecological risk index was constructed. The shift of gravity center and spatial statistics were used to reveal landscape ecological risk of Taihu Lake basin with temporal and spatial characteristics. The results showed that the ecological risk mainly was at medium and low levels in Taihu Lake basin, and the higher ecological risk areas were mainly distributed at the Taihu Lake area during 2000 to 2015, and the low ecological risk was transferred from the southwest and south of Taihu Lake to the developed areas in the northern part of Taihu Lake area. Spatial analysis showed that landscape ecological risk had negative correlation with natural factors, which was weakened gradually, while the correlation with socioeconomic factors trended to become stronger, with human disturbance affecting the landscape ecological risk significantly. The impact of socioeconomic factors on landscape ecological risks differed in different urbanization stages. In the developing area, with the economic development, the landscape was increasingly fragmented and the ecological risk was correspondingly increased. While in the developed area, with the further development of the economy, the aggregation index was increased, and fragmentation and separation indexes were decreased, ecological construction was restored, and the landscape ecological risk began to decline. CLUE-S model simulation showed that the ecological risk of Taihu Lake basin would be reduced in future, mainly on the low and relatively low levels. Taihu Lake area, both in history and the future, is a high ecological risk zone, and its management and protection should be strengthened.

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.

New explorations along the northern shores of Lake Bonneville

USGS Publications Warehouse

Oviatt, Charles G.; Miller, D.M.

1997-01-01

This field trip begins in Salt Lake City and makes a clockwise circuit of Great Salt Lake, with primary objectives to observe stratigraphie and geomorphic records of Lake Bonneville. Stops include Stansbury Island, Puddle Valley, gravel pits at Lakeside and the south end of the Hogup Mountains, several stops in Curlew Valley and Hansel Valley, and a final stop at the north end of Great Salt Lake east of the Promontory Mountains. Stratigraphie observations at gravel-pit and natural exposures will be linked to interpretations of lake-level change, which were caused by climate change. Evidence of paleoseismic and volcanic activity will be discussed at several sites, and will be tied to the lacustrine stratigraphic record. The trip provides an overview of the history of Lake Bonneville and introduces participants to some new localities with excellent examples of Lake Bonneville landforms and stratigraphy.

Dynamics of CFCs in northern temperate lakes and adjacent groundwater

USGS Publications Warehouse

Walker, John F.; Saad, David A.; Hunt, Randall J.

2007-01-01

Three dimictic lakes and one meromictic lake in and near the Trout Lake, Wisconsin, watershed were sampled to determine the variation of chlorofluorocarbon (CFC) concentrations within the lakes. The lakes were sampled during stratified conditions, during fall turnover, and during ice cover. The results demonstrate a considerable variation in CFC concentrations and corresponding atmospheric mixing ratios in the lakes sampled, both with depth and season within a given lake, and across different lakes. CFC profiles and observed degradation were not related to the groundwater inflow rate and hence are likely the result of in‐lake processes influenced by CFC degradation in the (lake) water column, CFC degradation in the lake‐bed sediments, and gas exchange rates and the duration of turnover (turnover efficiency).

Mercury and other element exposure in tree swallows nesting at low pH and neutral pH lakes in northern Wisconsin USA

USGS Publications Warehouse

Custer, Thomas W.; Custer, Christine M.; Thogmartin, Wayne E.; Dummer, Paul M.; Rossmann, Ronald; Kenow, Kevin P.; Meyer, Michael W.

2012-01-01

The primary objective of this study was to determine whether tree swallows (Tachycineta bicolor) demonstrate similar responses to lake pH and mercury (Hg) contamination in northern Wisconsin as do common loons (Gavia immer). Similar to common loons, Hg concentrations in the blood of tree swallow nestlings were higher, Hg concentrations in eggs tended to be higher, and egg size tended to be smaller at low (<6.2) pH lakes. In contrast to common loons, tree swallow nestling production was not lower at low pH lakes. Based on modeling associations, Hg concentrations in tree swallow eggs and nestling blood can be used to predict Hg concentrations in common loons without the invasive or destructive sampling of loons. Mean concentrations of cadmium, manganese, and mercury in nestling livers were higher at low pH lakes than neutral pH lakes. Concentrations of cadmium, chromium, mercury, selenium, and zinc were not at toxic levels.

Mercury and other element exposure in tree swallows nesting at low pH and neutral pH lakes in northern Wisconsin USA

USGS Publications Warehouse

Custer, T.W.; Custer, Christine M.; Thogmartin, W.E.; Dummer, P.M.; Rossmann, R.; Kenow, K.P.; Meyer, M.W.

2012-01-01

The primary objective of this study was to determine whether tree swallows (Tachycineta bicolor) demonstrate similar responses to lake pH and mercury (Hg) contamination in northern Wisconsin as do common loons (Gavia immer). Similar to common loons, Hg concentrations in the blood of tree swallow nestlings were higher, Hg concentrations in eggs tended to be higher, and egg size tended to be smaller at low (<6.2) pH lakes. In contrast to common loons, tree swallow nestling production was not lower at low pH lakes. Based on modeling associations, Hg concentrations in tree swallow eggs and nestling blood can be used to predict Hg concentrations in common loons without the invasive or destructive sampling of loons. Mean concentrations of cadmium, manganese, and mercury in nestling livers were higher at low pH lakes than neutral pH lakes. Concentrations of cadmium, chromium, mercury, selenium, and zinc were not at toxic levels. ?? 2011 Elsevier Ltd. All rights reserved.

Impacts of Recent Wetting on Snow Processes and Runoff Generation in a Terminal Lake Basin, Devils Lake, North Dakota.

NASA Astrophysics Data System (ADS)

Mahmood, T. H.; Van Hoy, D.

2016-12-01

The Devils Lake Basin, only terminal lake basin in North America, drains to a terminal lake called Devils Lake. Terminal lakes are susceptible to climate and land use changes as their water levels fluctuate to these changes. The streamflow from the headwater catchments of the Devils Lake basin exerts a strong control on the water level of the lake. Since, the mid-1980s, the Devils Lake Basin as well as other basins in the northern Great Plains have faced a large and abrupt surge in precipitation regime resulting in a series of wetter climatic condition and flooding around the Devils Lake area. Nevertheless, the impacts of the recent wetting on snow processes such as snow accumulations, blowing snow transport, in-transit sublimation, frozen soil infiltration and snowmelt runoff generations in a headwater catchment of the Devils Lake basin are poorly understood. In this study, I utilize a physically-based, distributed cold regions hydrological model to simulate the hydrological responses in the Mauvais Coulee basin that drains to Devils Lake. The Mauvais Coulee basin ( 1072 km2), located in the north-central North Dakota, is set in a gently rolling landscape with low relief ( 220 m) and an average elevation of 500 m. Major land covers are forest areas in turtle mountains ( 10%) and crops ( 86%), with wheat ( 25%) and canola ( 20%) as the major crops. The model set up includes ten sub-basins, each of which is divided into several hydrological response units (HRUs): riparian forest, river channel, reservoir, wheat, canola, other crops, and marsh. The model is parameterized using local and regional measurements and the findings from previous scientific studies. The model is evaluated against streamflow observations at the Mauvais Coulee gauge (USGS) during 1994-2013 periods using multiple performance criteria. Finally, the impacts of recent increases in precipitation on hydrologic responses are investigated using modeled hydrologic processes.

The Cottonwood Lake study area, a long-term wetland ecosystem monitoring site

USGS Publications Warehouse

Mushet, David M.; Euliss, Ned H.

2012-01-01

The Cottonwood Lake study area is one of only three long-term wetland ecosystem monitoring sites in the prairie pothole region of North America; the other two are Orchid Meadows in South Dakota and St. Denis in Saskatchewan. Of the three, Cottonwood Lake has, by far, the longest continuous data-collection record. Research was initiated at the study area in 1966, and intensive investigations of the hydrology, chemistry, and biology of prairie pothole wetlands continue at the site today. This fact sheet describes the study area, provides an overview of wetland ecology research that has been conducted at the site in the past, and provides an introduction to current work being conducted at the study area by USGS scientists.

77 FR 30320 - General Management Plan/Environmental Impact Statement, Ross Lake National Recreation Area, North...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-22

... Management Plan/Environmental Impact Statement, Ross Lake National Recreation Area, North Cascades National... Impact Statement for the new General Management Plan (GMP) for Ross Lake National Recreation Area, part... Wilderness Act of 1988. The full range of foreseeable environmental consequences from implementing the...

Titan's lakes and Mare observed by the Visual and Infrared Mapping Spectrometer

NASA Astrophysics Data System (ADS)

Brown, R. H.; Soderblom, L. A.; Sotin, C.; Barnes, J. W.; Hayes, A. G.; Lawrence, K. J.; Le Mouelic, S.; Rodriguez, S.; Soderblom, J. M.; Baines, K. H.; Buratti, B. J.; Clark, R. N.; Jaumann, R.; Nicholson, P. D.; Stephan, K.

2012-04-01

Titan is the only place, besides Earth, that holds stable liquid bodies at its surface. The large Kraken Mare, first seen by ISS [1], was then observed by the radar instrument that discovered a large number of small lakes as well as two other Mare [2]. The liquid nature of these radar-dark features was later confirmed by the specular reflection observed by the Visual and Infrared Mapping Spectrometer (VIMS) over Kraken Mare [3] and by the very low albedo at 5-micron over Ontario Lacus [4]. The three largest lakes are called Mare and are all located in the North Pole area. It is remarkable that most of these lakes have been observed on the North Pole with only one large lake, Ontario lacus, located in the South Pole area. This observation suggests the influence of orbital parameters on the meteorology and the occurrence of rainfalls to refill the depressions [5]. Ethane was detected by the VIMS instrument as one component of Ontario lacus [4]. These lakes and Mare play a key role in Titan's meteorology as demonstrated by recent global circulation models [6]. Determining the composition and the evolution of those lakes has become a primary science objective of the Cassini extended mission. Since Titan entered northern spring in August 2009, the North Pole has been illuminated allowing observations at optical wavelengths. On June 5, 2010 the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft observed the northern pole area with a pixel size from 3 to 7 km. These observations demonstrate that little of the solar flux at 5-micron is scattered by the atmosphere, which allowed us to build a mosaic covering an area of more than 500,000 km2 that overlaps and complements observations made by the Synthetic Aperture Radar (SAR) in 2007. We find that there is an excellent correlation between the shape of the radar dark area, known as Ligeia Mare and the VIMS 5-micron dark unit. Matching most of the radar shoreline, the 2010 VIMS observations suggest

Digital Geologic Map Database of Medicine Lake Volcano, Northern California

NASA Astrophysics Data System (ADS)

Ramsey, D. W.; Donnelly-Nolan, J. M.; Felger, T. J.

2010-12-01

Medicine Lake volcano, located in the southern Cascades ~55 km east-northeast of Mount Shasta, is a large rear-arc, shield-shaped volcano with an eruptive history spanning nearly 500 k.y. Geologic mapping of Medicine Lake volcano has been digitally compiled as a spatial database in ArcGIS. Within the database, coverage feature classes have been created representing geologic lines (contacts, faults, lava tubes, etc.), geologic unit polygons, and volcanic vent location points. The database can be queried to determine the spatial distributions of different rock types, geologic units, and other geologic and geomorphic features. These data, in turn, can be used to better understand the evolution, growth, and potential hazards of this large, rear-arc Cascades volcano. Queries of the database reveal that the total area covered by lavas of Medicine Lake volcano, which range in composition from basalt through rhyolite, is about 2,200 km2, encompassing all or parts of 27 U.S. Geological Survey 1:24,000-scale topographic quadrangles. The maximum extent of these lavas is about 80 km north-south by 45 km east-west. Occupying the center of Medicine Lake volcano is a 7 km by 12 km summit caldera in which nestles its namesake, Medicine Lake. The flanks of the volcano, which are dotted with cinder cones, slope gently upward to the caldera rim, which reaches an elevation of nearly 2,440 m. Approximately 250 geologic units have been mapped, only half a dozen of which are thin surficial units such as alluvium. These volcanic units mostly represent eruptive events, each commonly including a vent (dome, cinder cone, spatter cone, etc.) and its associated lava flow. Some cinder cones have not been matched to lava flows, as the corresponding flows are probably buried, and some flows cannot be correlated with vents. The largest individual units on the map are all basaltic in composition, including the late Pleistocene basalt of Yellowjacket Butte (296 km2 exposed), the largest unit on the

Mercury and other element exposure in tree swallows nesting at low pH and neutral pH lakes in northern Wisconsin USA

EPA Science Inventory

The primary objective of this study was to determine whether tree swallows (Tachycineta bicolor) demonstrate similar responses to lake pH and mercury (Hg) contamination in northern Wisconsin as do common loons (Gavia immer). Similar to common loons, Hg concentrations in the blood...

Predicting Late Winter Dissolved Oxygen Levels in Arctic Lakes Using Morphology and Landscape Metrics

NASA Astrophysics Data System (ADS)

Leppi, Jason C.; Arp, Christopher D.; Whitman, Matthew S.

2016-02-01

Overwintering habitat for Arctic freshwater fish is essential, such that understanding the distribution of winter habitat quality at the landscape-scale is warranted. Adequate dissolved oxygen (DO) is a major factor limiting habitat quality in the Arctic region where ice cover can persist for 8 months each year. Here we use a mixed-effect model developed from 20 lakes across northern Alaska to assess which morphology and landscape attributes can be used to predict regional overwintering habitat quality. Across all lakes, we found that the majority of the variations in late winter DO can be explained by lake depth and littoral area. In shallow lakes (<4 m), we found evidence that additional variables such as elevation, lake area, ice cover duration, and snow depth were associated with DO regimes. Low DO regimes were most typical of shallow lakes with large littoral areas and lakes that had high DO regimes often were lakes with limited littoral areas and deeper water. Our analysis identifies metrics that relate to late winter DO regimes in Arctic lakes that can aid managers in understanding which lakes will likely provide optimum DO for overwintering habitat. Conversely, lakes which predicted to have marginal winter DO levels may be vulnerable to disturbances that could lower DO below critical thresholds to support sensitive fish. In regions where lakes are also used by humans for industrial winter water supply, such as ice-road construction for oil and gas development, these findings will be vital for the management of resources and protection of Arctic fish.

Predicting Late Winter Dissolved Oxygen Levels in Arctic Lakes Using Morphology and Landscape Metrics.

PubMed

Leppi, Jason C; Arp, Christopher D; Whitman, Matthew S

2016-02-01

Overwintering habitat for Arctic freshwater fish is essential, such that understanding the distribution of winter habitat quality at the landscape-scale is warranted. Adequate dissolved oxygen (DO) is a major factor limiting habitat quality in the Arctic region where ice cover can persist for 8 months each year. Here we use a mixed-effect model developed from 20 lakes across northern Alaska to assess which morphology and landscape attributes can be used to predict regional overwintering habitat quality. Across all lakes, we found that the majority of the variations in late winter DO can be explained by lake depth and littoral area. In shallow lakes (<4 m), we found evidence that additional variables such as elevation, lake area, ice cover duration, and snow depth were associated with DO regimes. Low DO regimes were most typical of shallow lakes with large littoral areas and lakes that had high DO regimes often were lakes with limited littoral areas and deeper water. Our analysis identifies metrics that relate to late winter DO regimes in Arctic lakes that can aid managers in understanding which lakes will likely provide optimum DO for overwintering habitat. Conversely, lakes which predicted to have marginal winter DO levels may be vulnerable to disturbances that could lower DO below critical thresholds to support sensitive fish. In regions where lakes are also used by humans for industrial winter water supply, such as ice-road construction for oil and gas development, these findings will be vital for the management of resources and protection of Arctic fish.

Multiple Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California

USGS Publications Warehouse

Pike, Richard J.; Graymer, Russell W.

2008-01-01

With the exception of Los Angeles, perhaps no urban area in the United States is more at risk from landsliding, triggered by either precipitation or earthquake, than the San Francisco Bay region of northern California. By January each year, seasonal winter storms usually bring moisture levels of San Francisco Bay region hillsides to the point of saturation, after which additional heavy rainfall may induce landslides of various types and levels of severity. In addition, movement at any time along one of several active faults in the area may generate an earthquake large enough to trigger landslides. The danger to life and property rises each year as local populations continue to expand and more hillsides are graded for development of residential housing and its supporting infrastructure. The chapters in the text consist of: *Introduction by Russell W. Graymer *Chapter 1 Rainfall Thresholds for Landslide Activity, San Francisco Bay Region, Northern California by Raymond C. Wilson *Chapter 2 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike and Steven Sobieszczyk *Chapter 3 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven Sobieszczyk *Chapter 4 Landslide Hazard Modeled for the Cities of Oakland, Piedmont, and Berkeley, Northern California, from a M=7.1 Scenario Earthquake on the Hayward Fault Zone by Scott B. Miles and David K. Keefer *Chapter 5 Synthesis of Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike The plates consist of: *Plate 1 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike, Russell W. Graymer, Sebastian Roberts, Naomi B. Kalman, and Steven Sobieszczyk *Plate 2 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven

Influence of permafrost on lake terraces of Lake Heihai (NE Tibetan Plateau)

NASA Astrophysics Data System (ADS)

Lockot, Gregori; Hartmann, Kai; Wünnemann, Bernd

2013-04-01

The Tibetan Plateau (TP) is one of the key regions for climatic global change. Besides the poles the TP is the third highest storage of frozen water in glaciers. Here global warming is three times higher than in the rest of the world. Additionally the TP provides water for billions of people and influences the moisture availability from the Indian and East Asian monsoon systems. During the Holocene extent and intensity of the monsoonal systems changed. Hence, in the last decades, a lot of work was done to reconstruct timing and frequency of monsoonal moisture, to understand the past and give a better forecast for the future. Comparative workings often show very heterogeneous patterns of timing and frequency of the Holocene precipitation and temperature maximum, emphasizing the local importance of catchment dynamics. In this study we present first results of lake Heihai (36°N, 93°15'E, 4500m a.s.l.), situated at the north-eastern border of the TP. The lake is surrounded by a broad band of near-shore lake sediments, attesting a larger lake extent in the past. These sediments were uplifted by permafrost, reaching nowadays heights ca. +8 meters above present lake level. Due to the uplift one of the main inflows was blocked and the whole hydrology of the catchment changed. To quantify the uplift of permafrost Hot Spot Analysis were accomplished at a DEM of the near-shore area. As a result regions of high permafrost uplift and those which mirror the original height of lake ground were revealed. The most obvious uplift took place in the northern and western part of the lake, where the four uplift centers are located. In contrast the southern and eastern areas show a rather degraded pattern (probably by fluvial erosion, thermokarst, etc.). The ancient lake bottom, without permafrost uplift was estimated to be 4-6 meters above the modern lake level. For a better understanding of permafrost interaction inside the terrace bodies a 5m sediment profile was sampled and

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.

Archaeological Investigations in the Gainesville Lake Area of the Tennessee-Tombigbee Waterway. Volume I. The Gainesville Lake Area Excavations.

DTIC Science & Technology

1981-01-01

97 71. Site 1Pi61, Removing Trees ........ .................. . 97 72. Site lPi6l, Testing the Midden ....... ................ . 97 6...the use of plant and animal species changes through time. Volume IV also describes the human skeletal remains from all excavated sites and discusses the...Gainesville Lake area were cultural features. A few 5 features resulted from forces other than human behavior ( tree roots, ro- dent burrows, erosional gullies

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.

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

the AZ extensional corridor and NW-SE trans tension related to the Lake Mead shear zone are the main controls on groundwater flow in the vicinity of HD and Boulder City Pluton. Most groundwater in BC appears to discharge along the NW-striking Palm Tree fault that parallels the northern edge of the pluton. Supported by trends in chemistry, an alignment of similar-elevation springs along a N-S striking fault that extends the length of west BC may be a flow path for groundwater from north BC to south of the pluton. South of the pluton, dikes intrude many of the faults and appear to act as flow barriers. Groundwater in this part of BC may flow through stacked layers of brecciated volcanic rock prevalent in the area. Flow from laterally adjacent valleys into BC would have to cross a N-S structural fabric that is not favored kinematically. Existing information implies an overall absence of significant surface discharge in BC prior to construction of HD. This indicates that the head created by impoundment of the Colorado River has likely pushed old, slow moving groundwater through CRV and, possibly, south Lake Mead Valley, to the surface in BC where it discharges as springs and seeps.

Anthropic influences on the sedimentation rates of lakes situated in different geographic areas.

PubMed

Simon, Hedvig; Kelemen, Szabolcs; Begy, Róbert-Csaba

2017-07-01

The aim of this study is to determine the effects of natural and anthropic events occurring in the last 30 years in the catchment areas of four Romanian lakes (St. Anna Lake, Red Lake, Vârşolţ Lake and Matiţa Lake) originating from four different geomorphologic areas. A total of eleven sediment cores have been processed for age and sedimentation rate determination using the 210 Pb dating method. Total 210 Pb was measured via alpha spectrometry by 210 Po using PIPS detectors, while supported 210 Pb was measured by 226 Ra using HPGe detectors. Ages and sedimentation rates were calculated using the CRS model. The values of the sedimentation rates have grown multiply in the last three decades: 2.66 times in case of the St. Anna Lake (from 0.06 ± 0.01 g/cm 2 y to 0.16 ± 0.02 g/cm 2 y), up to 6.72 times in case of Red Lake (0.36 ± 0.04 g/cm 2 y to 2.42 ± 0.36 g/cm 2 y), 4.02 times in case of Vârşolţ Lake (04 g/cm 2 y to 1.53 ± 0.18 g/cm 2 y) and up to 16.18 times in case of Matiţa Lake (0.27 ± 0.03 g/cm 2 y to 4.37 ± 0.32). Copyright © 2016 Elsevier Ltd. All rights reserved.

Magnetic investigation of the mid-Holocene aged coastal lake Heimerdalsvatnet in the Lofoten Islands, northern Norway

NASA Astrophysics Data System (ADS)

Murdock, K. J.; Brown, L. L.

2012-12-01

The coastal lake Heimerdalsvatnet is located on the island of Vestvågøya in the Lofoten Islands off the northern coast of Norway. Recently, Balascio et al. (2011) performed a comprehensive investigation of the lake using bathymetric and sub-bottom profiles, bulk geochemistry, diatom assemblages, molecular biomarkers, high resolution X-ray fluorescence (XRF) scans, and magnetic susceptibility to study its geologic history over the past 7800 years. They determined the lake had undergone a regressive sea level sequence and identified three distinct and separate units exemplifying the transition of a restricted marine environment within the lake to a completely freshwater lacustrine setting. Unit I, located at the bottom of the 5.8m sediment core, spans 7800-6500 years before present and is at a period of time when sea level was higher than the edge of the lake basin. Magnetic susceptibility is extremely low during this period, and it is theorized that this is due to stratification within the lake from a density difference between the marine salt water and the influx of freshwater. Unit II is broken into Unit IIa and IIb, making up the transitional period within the lake history from 6500 to 4900 years before present. This phase is marked by fluxes of higher and lower magnetic susceptibility and shifts between more freshwater to brackish water biological markers. Unit III (4900 years to present) has high magnetic susceptibility compared to the other two units, and represents the final stage of the lake as a completely freshwater environment. Questions remain about the lake, such as what was driving the changes in magnetic susceptibility? Was it dilution of the magnetic grains due to higher productivity of organisms within the lake, or is it related to dissolution of magnetite due to anoxic conditions caused by lake stratification? Rock magnetic investigations using magnetic susceptibility, hysteresis parameters, and Curie temperature analyses have led to a better

SCOPSCO - Scientific Collaboration On Past Speciation Conditions in Lake Ohrid

NASA Astrophysics Data System (ADS)

Wagner, B.; Wilke, T.; Grazhdani, A.; Kostoski, G.; Krastel, S.; Reicherter, K. R.; Zanchetta, G.

2009-12-01

Lake Ohrid is a transboundary lake with approximately two thirds of its surface area belonging to the Former Yugoslav Republic of Macedonia and about one third belonging to the Republic of Albania. With more than 210 endemic species described, the lake is a unique aquatic ecosystem and a hotspot of biodiversity. This importance was emphasized, when the lake was declared a UNESCO World Heritage Site in 1979. Though the lake is considered to be the oldest, continuously existing lake in Europe, the age and the origin of Lake Ohrid are not completely unravelled to date. Age estimations vary between one and ten million years and concentrate around two to five million years, and both marine and limnic origin is proposed. Extant sedimentary records from Lake Ohrid cover the last glacial/interglacial cycle and reveal that Lake Ohrid is a valuable archive of volcanic ash dispersal and climate change in the central northern Mediterranean region. These records, however, are too short to provide information about the age and origin of the lake and to unravel the mechanisms controlling the evolutionary development leading to the extraordinary high degree of endemism. Concurrent genetic brakes in several invertebrate groups indicate that major geological and/or environmental events must have shaped the evolutionary history of endemic faunal elements in Lake Ohrid. High-resolution hydroacoustic profiles taken between 2004 and 2008, and multichannel seismic (Mini-GI-Gun) studies in 2007 and 2008 demonstrate well the interplay between sedimentation and active tectonics and impressively prove the potential of Lake Ohrid for an ICDP drilling campaign. The maximal sediment thickness is c. 680 m in the central basin, where unconformities or erosional features are absent. Thus the complete history of the lake is likely recorded. A deep drilling in Lake Ohrid would help (i) to obtain more precise information about the age and origin of the lake, (ii) to unravel the seismotectonic history

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

... DEPARTMENT OF THE INTERIOR Bureau of Reclamation New Melones Lake Area Resource Management Plan...) has made available for public review a Final RMP/EIS for the New Melones Lake Area. The Final RMP/EIS... Dan Holsapple, Acting New Melones Resource Manager, Bureau of Reclamation, at 209-536- 9094...

Long-Term Remote Monitoring of Three Typical Lake Area Variations in the Northwest China Over the Past 40 Years

NASA Astrophysics Data System (ADS)

Liu, Y.; Lu, Y.; Li, Y.; Yue, H.

2018-04-01

water resources management and sustainable development strategy, but also provide reference for assessing the impact of climate change and human activities. This paper selects three inland lakes in Northwest China, using Landsat MSS/TM/ETM+/OLI data from 1970 to 2015, Normalized Difference Water Index (NDWI) and Modified Normalized Difference Water Index (MNDWI) were used to extract lake area and analysed the dynamic trends. Meteorological station rainfall, evaporation and other meteorological data of the lakes were used to analyse reasons for the area change. The results showed that area of Hongjiannao Lake in the past 40 a was reduced, the groundwater impoundment and underground coal mining are the main cause of area reduction; the area of Bosten Lake in recent 40 a showed a decreasing trend after the first increase, the area was mainly affected by the surface runoff and snowmelt; the area of Qinghai Lake in the past 40 a shows a trend of decreasing first and then increasing, the change of its area is mainly affected by regional precipitation and the inflow.

Use of a Generalized Additive Model to Investigate Key Abiotic Factors Affecting Microcystin Cellular Quotas in Heavy Bloom Areas of Lake Taihu

PubMed Central

Tao, Min; Xie, Ping; Chen, Jun; Qin, Boqiang; Zhang, Dawen; Niu, Yuan; Zhang, Meng; Wang, Qing; Wu, Laiyan

2012-01-01

Lake Taihu is the third largest freshwater lake in China and is suffering from serious cyanobacterial blooms with the associated drinking water contamination by microcystin (MC) for millions of citizens. So far, most studies on MCs have been limited to two small bays, while systematic research on the whole lake is lacking. To explain the variations in MC concentrations during cyanobacterial bloom, a large-scale survey at 30 sites across the lake was conducted monthly in 2008. The health risks of MC exposure were high, especially in the northern area. Both Microcystis abundance and MC cellular quotas presented positive correlations with MC concentration in the bloom seasons, suggesting that the toxic risks during Microcystis proliferations were affected by variations in both Microcystis density and MC production per Microcystis cell. Use of a powerful predictive modeling tool named generalized additive model (GAM) helped visualize significant effects of abiotic factors related to carbon fixation and proliferation of Microcystis (conductivity, dissolved inorganic carbon (DIC), water temperature and pH) on MC cellular quotas from recruitment period of Microcystis to the bloom seasons, suggesting the possible use of these factors, in addition to Microcystis abundance, as warning signs to predict toxic events in the future. The interesting relationship between macrophytes and MC cellular quotas of Microcystis (i.e., high MC cellular quotas in the presence of macrophytes) needs further investigation. PMID:22384128

View of Lake Mead and Las Vegas, Nevada area from Sklyab

NASA Technical Reports Server (NTRS)

1973-01-01

A vertical view of the Lake Mead and Las Vegas, Nevada area as photographed from Earth orbit by one of the six lenses of the Itek-furnished S190-A Multispectral Photographic Facility Experiment aboard the Skylab space station. Lake Mead is water of the Colorado River impounded by Hoover Dam. Most of the land in the picture is Nevada, however, a part of the northwest corner of Arizona can be seen.

[Fleas on small mammals in the surrounding area of Erhai Lake].

PubMed

Dong, Wen-Ge; Guo, Xian-Guo; Men, Xing-Yuan; Gong, Zheng-Da; Wu, Dian; Zhang, Zheng-Kun; Zhang, Li-Yun

2009-12-01

To investigate the distribution pattern, species diversity and community structure of fleas on small mammals in the surrounding area of Erhai Lake, and the relationship between fleas and their hosts. Different geographical areas surrounding the Erhai Lake in Yunnan were selected as investigated spots. Small mammals were captured with baited cages. The cage-traps were examined and re-baited each morning. All fleas on the hosts were collected and identified. The richness (S), evenness (J'), diversity index (H'), dominance index (C'), total ectoparasite infestation rate (Rpt), total ectoparasite infestation index (Ipt), and constituent ratio (Cr) were used to measure the community structure. Altogether, 3,303 small mammals and 3,243 fleas were collected. From the 21 species of small mammal hosts, 13 species of fleas were identified. In southern area of the Lake, the species richness (21 species of small mammals & 12 species of fleas) was highest among the three selected areas. Seventeen species of small mammals and 8 species of fleas were found in eastern area, and only 13 species of small mammals and 7 species of fleas found in the west. This implied the probable influences of ecological environments on the fleas and their corresponding hosts. The community structure of fleas on small mammals was complex. The species diversity, species composition, community structure and distribution pattern of fleas were simultaneously influenced by the hosts' body surface microenvironment and the macroenvironment (habitat). The fleas are commonly distributed in small mammals in the areas and their communities are related to host species and the habitats.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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) willmore » 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.« less

Holocene climate on the Modoc Plateau, northern California, USA: The view from Medicine Lake

USGS Publications Warehouse

Starratt, Scott W.

2009-01-01

Medicine Lake is a small (165 ha), relatively shallow (average 7.3 m), intermediate elevation (2,036 m) lake located within the summit caldera of Medicine Lake volcano, Siskiyou County, California, USA. Sediment cores and high-resolution bathymetric and seismic reflection data were collected from the lake during the fall of 1999 and 2000. Sediments were analyzed for diatoms, pollen, density, grain size (sand/mud ratio), total organic carbon (TOC), and micro-scale fabric analysis. Using both 14C (AMS) dating and tephrochronology, the basal sediments were estimated to have been deposited about 11,400 cal year BP, thus yielding an estimated average sedimentation rate of about 20.66 cm/1,000 year. The lowermost part of the core (11,400–10,300 cal year BP) contains the transition from glacial to interglacial conditions. From about 11,000–5,500 cal year BP, Medicine Lake consisted of two small, steep-sided lakes or one lake with two steep-sided basins connected by a shallow shelf. During this time, both the pollen (Abies/Artemisia ratio) and the diatom (Cyclotella/Navicula ratio) evidences indicate that the effective moisture increased, leading to a deeper lake. Over the past 5,500 years, the pollen record shows that effective moisture continued to increase, and the diatom record indicates fluctuations in the lake level. The change in the lake level pattern from one of the increasing depths prior to about 6,000 cal year BP to one of the variable depths may be related to changes in the morphology of the Medicine Lake caldera associated with the movement of magma and the eruption of the Medicine Lake Glass Flow about 5,120 cal year BP. These changes in basin morphology caused Medicine Lake to flood the shallow shelf which surrounds the deeper part of the lake. During this period, the Cyclotella/Navicula ratio and the percent abundance of Isoetes vary, suggesting that the level of the lake fluctuated, resulting in changes in the shelf area

Use of the emergency room in Elliot Lake, a rural community of Northern Ontario, Canada.

PubMed

Harris, L; Bombin, M; Chi, F; DeBortoli, T; Long, J

2004-01-01

There is ample documentation that use of hospital emergency facilities for reasons other than urgencies/emergencies results in clogged services in many urban centers. However, little has been published about similar misuse of emergency rooms/departments in rural and remote areas, where the situation is usually compounded by a scarcity of healthcare professionals. In Canada there is a shortage of physicians in rural and remote areas as a consequence of misdistribution (most physicians staying in southern urban centers after residence), and there is a chronic misuse of facilities meant for urgencies/emergencies to cope with primary healthcare needs. We address the problem in Elliot Lake, a rural Northern Ontario community of 12,000 people. The economy of Elliot Lake was based on uranium mining until the mid-1990s, when it drastically changed to become a center for affordable retirement and recreational tourism. As a consequence, at the present time the proportion of seniors in Elliot Lake doubles the Canadian average. Our objectives are to elucidate the demographics of emergency room (ER) clients and the effect of the elderly population; the nature of ER use; the perceived level of urgency of clients versus health professionals; and possible alternatives offered to non-urgent/emergency visits. This is the first study of the kind in Northern Ontario, a region the size of France. The study, conducted in July 2001, used a prospective survey, completed by patients and attending clinicians at the time of a patient's presentation to the ER of St Joseph's General Hospital. This hospital is staffed by family physicians, a nurse practitioner, and registered nurses (RNs). The catchment area population (town plus surrounding areas) of the hospital is approximately 18,000 people. ER clients were interviewed verbally, and the attending health professionals responded to written questionnaires. Demographics were recorded (age, sex, employment and marital status), as was each client

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

Lake levels, streamflow, and surface-water quality in the Devils Lake area, North Dakota

USGS Publications Warehouse

Wiche, Gregg J.

1996-01-01

The Devils Lake Basin is a 3,810-square-mile (mi2) closed basin (fig. 1) in the Red River of the North Basin. About 3,320 mi2 of the total 3,810 mi2 is tributary to Devils Lake; the remainder is tributary to Stump Lake.Since glaciation, the lake level of Devils Lake has fluctuated from about 1,457 feet (ft) above sea level (asl), the natural spill elevation of the lake to the Sheyenne River, to 1,400 ft asl (Aronow, 1957). Although no documented records of lake levels are available before 1867, Upham (1895, p. 595), on the basis of tree-ring chronology, indicated that the lake level was 1,441 ft asl in 1830. Lake levels were recorded sporadically from 1867 to 1901 when the U.S. Geological Survey established a gaging station on Devils Lake. From 1867 to the present (1996), the lake level has fluctuated between a maximum of 1,438.4 ft asl in 1867 and a minimum of 1,400.9 ft asl in 1940 (fig. 2). On July 31, 1996, the lake level was 1,437.8 ft asl, about 15.2 ft higher than the level recorded in February 1993 and the highest level in about 120 years.Since 1993, the lake level of Devils Lake (fig. 2) has risen rapidly in response to above-normal precipitation from the summer of 1993 to the present, and 30,000 acres of land around the lake have been flooded. The above-normal precipitation also has caused flooding elsewhere in the Devils Lake Basin. State highways near Devils Lake are being raised, and some local roads have been closed because of flooding.In response to the flooding, the Devils Lake Basin Interagency Task Force, comprised of many State and Federal agencies, was formed in 1995 to find and propose intermediate (5 years or less) solutions to reduce the effects of high lake levels. In addition to various planning studies being conducted by Federal agencies, the North Dakota State Water Commission has implemented a project to store water on small tracts of land and in the chain of lakes (Sweetwater Lake, Morrison Lake, Dry Lake, Mikes Lake, Chain Lake

Lake Yoa (Northern Chad): A Seasonal Footprint of 10,500 Years of Climate Change in the Sahara

NASA Astrophysics Data System (ADS)

Kroepelin, S.; Cocquyt, C.; Darius, F.; Dinies, M.; Francus, P.; Just, J.; Karls, J.; Kuper, J.; Lézine, A. M.; Mallaye, B.; Melles, M.; Sylvestre, F.; Viehberg, F. A.; Wennrich, V.

2016-12-01

We present Africa's most complete Holocene climate record in a long awaited breakthrough that few would have expected in one of the driest and most remote parts of the Sahara, the planet's major hot desert. A 16 m thick continuous sequence of seasonally laminated (varved) deposits at the bottom of a now fully groundwater-supported oasis lake at Ounianga Kebir in northern Chad extends our earlier 6,000 year record published in 2008 back to the onset of postglacial humid conditions 10,500 years ago in unrivalled detail. Main results indicate a rather slow regreening in northern Africa after 100,000 years of apparently continuous late Pleistocene aridity; precisely define the severe environmental impact of global climate events such as the 8,200 BP North Atlantic cooling even in hypercontinental positions far away from the oceans; and corroborate the gradual termination of the last "Green Sahara" period over millennia. Lake Yoa's varve count-controlled age model also shows the high error potential of the existing 14C chronology from bulk carbonate-dated paleolacustrine archives elsewhere in the Sahara and provides a basis for its correction. The new terrestrial multiproxy data set discloses agreements and discrepancies to marine and ice core data, and numeric climate models. As a natural analogue, it helps to foresee how North Africa's climate and environments might evolve due to anthropogenic global warming.

SCOPSCO - Scientific Collaboration On Past Speciation Conditions in Lake Ohrid

NASA Astrophysics Data System (ADS)

Vogel, Hendrik; Wagner, Bernd; Wilke, Thomas; Grazhdani, Andon; Kostoski, Goce; Krastel-Gudegast, Sebastian; Reicherter, Klaus; Zanchetta, Giovanni

2010-05-01

Lake Ohrid is a transboundary lake with approximately two thirds of its surface area belonging to the Former Yugoslav Republic of Macedonia and about one third belonging to the Republic of Albania. With more than 210 endemic species described, the lake is a unique aquatic ecosystem and a hotspot of biodiversity. This importance was emphasized, when the lake was declared a UNESCO World Heritage Site in 1979, and included as a target area of the International Continental Scientific Drilling Program (ICDP) already in 1993. Though the lake is considered to be the oldest, continuously existing lake in Europe, the age and the origin of Lake Ohrid are not completely unravelled to date. Age estimations vary between one and ten million years and concentrate around two to five million years, and both marine and limnic origin is proposed. Extant sedimentary records from Lake Ohrid cover the last glacial/interglacial cycle and reveal that Lake Ohrid is a valuable archive of volcanic ash dispersal and climate change in the central northern Mediterranean region. These records, however, are too short to provide information about the age and origin of the lake and to unravel the mechanisms controlling the evolutionary development leading to the extraordinary high degree of endemism. Concurrent genetic brakes in several invertebrate groups indicate that major geological and/or environmental events must have shaped the evolutionary history of endemic faunal elements in Lake Ohrid. High-resolution hydroacoustic profiles (INNOMAR SES-96 light and INNOMAR SES-2000 compact) taken between 2004 and 2008, and multichannel seismic (Mini-GI-Gun) studies in 2007 and 2008 demonstrate well the interplay between sedimentation and active tectonics and impressively prove the potential of Lake Ohrid for an ICDP drilling campaign. The maximal sediment thickness is ˜680 m in the central basin, where unconformities or erosional features are absent. Thus the complete history of the lake is likely

Quaternary geology of the Boston area: Glacial events from Lake Charles to Lake Aberjona

USGS Publications Warehouse

Stone, Byron D.; Lane, John W.

2014-01-01

The multiple-glacial and glaciomarine Quaternary history of the Boston, Massachusetts area has been known generally since the earliest studies of the then newly recognized glacial deposits described by Prof. Louis Agassiz in the late1840’s and fossil marine shells in the drift in the 1850’s. Attention then turned to possible glacial erosional effects on the preglacial bedrock physiography, as related to rock units and structure, and to the challenges of defining useful physical and lithic characteristics of the drift by Prof. W.O. Crosby and others, 1880-1900. The problems of deducing the relative stratigraphic order among such small, fossil-barren surficial sedimentary deposits, and extending knowledge gained from studies of postulated ancient glacial lakes to a regional understanding of the history of many lakes during the retreat of the ice sheet required field work and use of geologic maps. With the advent of modern topographic maps in the 1880’s, the early period of discovery included field studies of glacial lake deposits in local river basins in the Boston region, basins that drain northward, thereby creating glacial lake basins dammed by the ice margin as it retreated to the north. Guided by M.I.T. and Harvard professors W.O. Crosby, N.S. Shaler, J.B. Woodworth, W.M. Davis, and others in the 1880-1920 period, the first Quaternary glacial stratigraphers were students (e.g. Crosby and Grabau, 1896, Clapp, 1905, Fuller 1905, Goldthwaite 1906, Grabau, 1906, Taylor, Tight).

Lateral spread hazard mapping of the northern Salt Lake Valley, Utah, for a M7.0 scenario earthquake

USGS Publications Warehouse

Olsen, M.J.; Bartlett, S.F.; Solomon, B.J.

2007-01-01

This paper describes the methodology used to develop a lateral spread-displacement hazard map for northern Salt Lake Valley, Utah, using a scenario M7.0 earthquake occurring on the Salt Lake City segment of the Wasatch fault. The mapping effort is supported by a substantial amount of geotechnical, geologic, and topographic data compiled for the Salt Lake Valley, Utah. ArcGIS?? routines created for the mapping project then input this information to perform site-specific lateral spread analyses using methods developed by Bartlett and Youd (1992) and Youd et al. (2002) at individual borehole locations. The distributions of predicted lateral spread displacements from the boreholes located spatially within a geologic unit were subsequently used to map the hazard for that particular unit. The mapped displacement zones consist of low hazard (0-0.1 m), moderate hazard (0.1-0.3 m), high hazard (0.3-1.0 m), and very high hazard (> 1.0 m). As expected, the produced map shows the highest hazard in the alluvial deposits at the center of the valley and in sandy deposits close to the fault. This mapping effort is currently being applied to the southern part of the Salt Lake Valley, Utah, and probabilistic maps are being developed for the entire valley. ?? 2007, Earthquake Engineering Research Institute.

Changes in bathymetry for Lake Katherine and Wood Lake, Richland County, South Carolina, 1989-93

USGS Publications Warehouse

Patterson, Glenn G.

1995-01-01

Bathymetric surveys of Lake Katherine and Wood Lake, small residential lakes in Columbia, South Carolina, were made in 1989 and 1993. During this period the combined volume of the lakes decreased by 519,000 cubic feet (11.9 acre-feet). Most of the decrease in volume occurred in the northern part of Lake Katherine where deltaic sediment deposits at the mouth of Gills Creek increased in thickness during the 4-year period. The sediment was derived from a combination of sources in the Gills Creek Basin upstream from the lakes. Construction of a highway and a housing development in the Basin were significant factors in the sedimentation.

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.

Differential response of vegetation in Hulun Lake region at the northern margin of Asian summer monsoon to extreme cold events of the last deglaciation

NASA Astrophysics Data System (ADS)

Zhang, Shengrui; Xiao, Jule; Xu, Qinghai; Wen, Ruilin; Fan, Jiawei; Huang, Yun; Yamagata, Hideki

2018-06-01

The response of vegetation to extreme cold events during the last deglaciation is important for assessing the impact of possible extreme climatic events on terrestrial ecosystems under future global warming scenarios. Here, we present a detailed record of the development of regional vegetation in the northern margin of Asian summer monsoon during the last deglaciation (16,500-11,000 cal yr BP) based on a radiocarbon-dated high-resolution pollen record from Hulun Lake, northeast China. The results show that the regional vegetation changed from subalpine meadow-desert steppe to mixed coniferous and deciduous forest-typical steppe during the last deglaciation. However, its responses to the Heinrich event 1 (H1) and the Younger Dryas event (YD) were significantly different: during the H1 event, scattered sparse forest was present in the surrounding mountains, while within the lake catchment the vegetation cover was poor and was dominated by desert steppe. In contrast, during the YD event, deciduous forest developed and the proportion of coniferous forest increased in the mountains, the lake catchment was occupied by typical steppe. We suggest that changes in Northern Hemisphere summer insolation and land surface conditions (ice sheets and sea level) caused temperature and monsoonal precipitation variations that contributed to the contrasting vegetation response during the two cold events. We conclude that under future global warming scenarios, extreme climatic events may cause a deterioration of the ecological environment of the Hulun Lake region, resulting in increased coniferous forest and decreased total forest cover in the surrounding mountains, and a reduction in typical steppe in the lake catchment.

Guidance for Delisting Michigan’s Great Lakes Areas of Concern

EPA Pesticide Factsheets

A useful tool for guidance in delisting Michigan’s Areas of Concern. Technical staff in the Michigan Department of Environmental Quality (MDEQ), the Michigan Department of Natural Resources (MDNR), USEPA Great Lakes National Program Office, among others.

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

Geology of the Ivanhoe Hg-Au district, northern Nevada: Influence of Miocene volcanism, lakes, and active faulting on epithermal mineralization

USGS Publications Warehouse

Wallace, A.R.

2003-01-01

The mercury-gold deposits of the Ivanhoe mining district in northern Nevada formed when middle Miocene rhyolitic volcanism and high-angle faulting disrupted a shallow lacustrine environment. Sinter and replacement mercury deposits formed at and near the paleosurface, and disseminated gold deposits and high-grade gold-silver veins formed beneath the hot spring deposits. The lacustrine environment provided abundant meteoric water; the rhyolites heated the water; and the faults, flow units, and lakebeds provided fluid pathways for the hydrothermal fluids. A shallow lake began to develop in the Ivanhoe area about 16.5 Ma. The lake progressively expanded and covered the entire area with fine-grained lacustrine sediments. Lacustrine sedimentation continued to at least 14.4 Ma, and periodic fluctuations in the size and extent of the lake may have been responses to both climate and nearby volcanism. The eruption of rhyolite and andesite flows and domes periodically disrupted the lacustrine environment and produced interfingered flows and lake sediments. The major pulse of rhyolitic volcanism took place between 15.16 ± 0.05 and 14.92 ± 0.05 Ma. High-angle faulting began in the basement about 15.2 Ma, penetrated to and disrupted the paleosurface after 15.10 ± 0.06 Ma, and largely ceased by 14.92 ± 0.05 Ma. Ground motion related to both faulting and volcanism created debris flows and soft-sediment deformation in the lakebeds. Mercury-gold mineralization was coeval with rhyolite volcanism and high-angle faulting, and it took place about 15.2 to 14.9 Ma. At and near the paleosurface, hydrothermal fluids migrated through tuffaceous sediments above relatively impermeable volcanic and Paleozoic units, creating chalcedonic, cinnabar-bearing replacement bodies and sinters. Disseminated gold was deposited in sedimentary and volcanic rocks beneath the mercury deposits, although the hydrologic path between the two ore types is unclear. Higher-grade gold-silver deposits formed in

50 CFR Table 43 to Part 679 - Northern Bering Sea Research Area

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Northern Bering Sea Research Area 43 Table 43 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ALASKA Pt. 679, Table 43 Table 43 to Part 679—Northern Bering Sea Research Area Longitude Latitude 1687...

Simulation of the shallow aquifer in the vicinity of Silver Lake, Washington County, Wisconsin, using analytic elements

USGS Publications Warehouse

Dunning, C.P.; Thomas, Judith Coffman; Lin, Yu-Feng

2003-01-01

A Silver Lake water budget was defined using both published hydrologic data and simulations using the calibrated model. Model simulations show that 1.08 cubic feet per second of ground water enters Silver Lake on the upgradient (primarily western) side and 0.08 cubic feet per second recharges to ground water on the downgradient (primarily eastern) side. Net precipitation (precipitation minus evaporation) on the lake is 0.04 cubic feet per second. Collectively, these water-budget terms provide a residual value of 1.04 cubic feet per second flow to Silver Creek at the north end of Silver Lake, which is a very good match to the range of measured flow (0.7 to 5.2 cubic feet per second). Ground-water recharge areas for Silver Lake are largely on the western side of the lake. The recharge area for the northern two-thirds of Silver Lake is west toward Big Cedar Lake. Assuming a porosity of 20 percent, model results indicate that the 50-year time-of-travel for recharge to Silver Lake does not extend to Big Cedar Lake. The recharge area for the southern one-third of Silver Lake is west toward Little Cedar Lake. Model results indicate that time of travel for recharge to Silver Lake from Little Cedar Lake is about 15 to 20 years. For travel times greater than 15 or 20 years, the ground-water recharge area for Little Cedar Lake and inflow from Big Cedar Lake also should be considered recharge affecting Silver Lake. Solute flux toward Silver Lake was calculated based on simulated ground-water flux and measured concentrations in the upgradient piezometers and observation wells.

A thiotrophic microbial community in an acidic brine lake in Northern Chile.

PubMed

Escudero, Lorena; Oetiker, Nia; Gallardo, Karem; Tebes-Cayo, Cinthya; Guajardo, Mariela; Nuñez, Claudia; Davis-Belmar, Carol; Pueyo, J J; Chong Díaz, Guillermo; Demergasso, Cecilia

2018-05-10

The endorheic basins of the Northern Chilean Altiplano contain saline lakes and salt flats. Two of the salt flats, Gorbea and Ignorado, have high acidic brines. The causes of the local acidity have been attributed to the occurrence of volcanic native sulfur, the release of sulfuric acid by oxidation, and the low buffering capacity of the rocks in the area. Understanding the microbial community composition and available energy in this pristine ecosystem is relevant in determining the origin of the acidity and in supporting the rationale of conservation policies. Besides, a comparison between similar systems in Australia highlights key microbial components and specific ones associated with geological settings and environmental conditions. Sediment and water samples from the Salar de Gorbea were collected, physicochemical parameters measured and geochemical and molecular biological analyses performed. A low diversity microbial community was observed in brines and sediments dominated by Actinobacteria, Algae, Firmicutes and Proteobacteria. Most of the constituent genera have been reported to be either sulfur oxidizing microorganisms or ones having the potential for sulfur oxidation given available genomic data and information drawn from the literature on cultured relatives. In addition, a link between sulfur oxidation and carbon fixation was observed. In contrast, to acid mine drainage communities, Gorbea microbial diversity is mainly supported by chemolithoheterotrophic, facultative chemolithoautotrophic and oligotrophic sulfur oxidizing populations indicating that microbial activity should also be considered as a causative agent of local acidity.

Recreation Carrying Capacity Facts and Considerations. Report 2. Benbrook Lake Project Area.

DTIC Science & Technology

1980-07-01

Lake and the representa- tives from the Fort Worth District Office. Their contributions of practical experi- ence and knowledge , along with their...Acceptability of techniques - Table 8 indicates the acceptability of different techniques for solving problems to the boaters and water- skiers surveyed at...boats near swimming areas. Boater/water- Boaters, especially jet e consider lake zoning, e.g. restrict skier conflicts boaters, are sometimes waterskiing

Bathymetry of Walker Lake, West-Central Nevada

USGS Publications Warehouse

Lopes, Thomas J.; Smith, J. LaRue

2007-01-01

the shore and river mouth that could be boulders, tree stumps, logs, or other submerged objects. The echosounder detected what appeared to be mounds in the deepest parts of Walker Lake, miles from the shore and river mouth. However, side-scan sonar and divers did not confirm the presence of mounds. Anomalies occur in two northwest trending groups in northern and southern Walker Lake. It is hypothesized that some anomalies indicate spring discharge along faults based on tufa-like rocks that were observed and the northwest trend parallel to and in proximity of mapped faults. Also, evaporation measured from Walker Lake is about 50 percent more than the previous estimate, indicating more water is flowing into the lake from sources other than the Walker River. Additional studies need to be done to determine what the anomalies are and whether they are related to the hydrology of Walker Lake. Most differences in surface area and storage volume between this study and a study by Rush in 1970 were less than 1 percent. The largest differences occur at lake-surface altitudes less than 3,916 feet. In general, relations between lake-surface altitude, surface area, and storage volume from Rush's study and this study are nearly identical throughout most of the range in lake-surface altitude. The lake-surface altitude in 1882 was estimated to be between 4,080 feet and 4,086 feet with a probable altitude of 4,082 feet. This estimate compares well with two previous estimates of 4,083 feet and 4,086 feet. Researchers believe the historic highstand of Walker Lake occurred in 1868 and estimated the highstand was between 4,089 feet and 4,108 feet. By 1882, Mason Valley was predominantly agricultural. The 7-26 feet decline in lake-surface altitude between 1868 and 1882 could partially be due to irrigation diversions during this time.

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

Lake Mead, NV

NASA Technical Reports Server (NTRS)

1973-01-01

Lake Mead, Nevada, (36.0N, 114.5E) where the water from the Colorado River empties after it's 273 mile journey through the Grand Canyon of Arizona is the subject of this photo. Other features of interest are Hoover Dam on the south shore of Lake Mead where cheap hydroelectric power is secondary to the water resources made available in this northern desert region and the resort city of Las Vegas, just to the west of Lake Mead. In this harsh desert environment, color infrared photography readily penetrates haze, detects and portrays vegetation as shades of red.

Holocene environmental changes inferred from biological and sedimentological proxies in a high elevation Great Basin lake in the northern Ruby Mountains, Nevada, USA

USGS Publications Warehouse

Wahl, David B.; Starratt, Scott W.; Anderson, Lysanna; Kusler, Jennifer E.; Fuller, Christopher C.; Addison, Jason A.; Wan, Elmira

2015-01-01

Multi-proxy analyses were conducted on a sediment core from Favre Lake, a high elevation cirque lake in the northern Ruby Mountains, Nevada, and provide a ca. 7600 year record of local and regional environmental change. Data indicate that lake levels were lower from 7600-5750 cal yr BP, when local climate was warmer and/or drier than today. Effective moisture increased after 5750 cal yr BP and remained relatively wet, and possibly cooler, until ca. 3750 cal yr BP. Results indicate generally dry conditions but also enhanced climatic variability from 3750-1750 cal yr BP, after which effective moisture increased. The timing of major changes in the Favre Lake proxy data are roughly coeval and in phase with those recorded in several paleoclimate studies across the Great Basin, suggesting regional climatic controls on local conditions and similar responses at high and low altitudes.

Osprey distribution, abundance, and status in western North America: I. The northern California population

USGS Publications Warehouse

Henny, Charles J.; Dunaway, David J.; Mallette, Robert D.; Koplin, James R.

1978-01-01

An estimated 355± 40 pairs (95 percent C.I.) of Ospreys (Pandion haliaetus carolinensis) nested in the northern California survey area in 1975. Eighty-one pairs were estimated along the extreme northern coast in Del Norte and Humboldt Counties. One hundred and forty-four pairs were estimated along California's northern coast in Mendociuo, Sonoma, and Marin Counties. The northern interior region, primarily in Siskiyou, Trinity, Shasta, Lassen, and Plumas Counties, contained an estimated 130 pairs. Forty-nine percent of the interior Osprey population is associated with reservoirs that were not present in 1900. We believe more Ospreys are present in the interior now than 75 years ago because of the increase in suitable habitat; nevertheless, populations at Shasta Lake and Clair Engle Lake are now exhibiting below-normal production rates and local declines. The long-term status of the coastal population, nesting along rivers, streams, and bays, is not clear. Recent production rates from two segments of the coastal population appear to be normal, but production at Usal Creek is below normal.

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

The importance of diverse data types to calibrate a watershed model of the Trout Lake Basin, Northern Wisconsin, USA

USGS Publications Warehouse

Hunt, R.J.; Feinstein, D.T.; Pint, C.D.; Anderson, M.P.

2006-01-01

As part of the USGS Water, Energy, and Biogeochemical Budgets project and the NSF Long-Term Ecological Research work, a parameter estimation code was used to calibrate a deterministic groundwater flow model of the Trout Lake Basin in northern Wisconsin. Observations included traditional calibration targets (head, lake stage, and baseflow observations) as well as unconventional targets such as groundwater flows to and from lakes, depth of a lake water plume, and time of travel. The unconventional data types were important for parameter estimation convergence and allowed the development of a more detailed parameterization capable of resolving model objectives with well-constrained parameter values. Independent estimates of groundwater inflow to lakes were most important for constraining lakebed leakance and the depth of the lake water plume was important for determining hydraulic conductivity and conceptual aquifer layering. The most important target overall, however, was a conventional regional baseflow target that led to correct distribution of flow between sub-basins and the regional system during model calibration. The use of an automated parameter estimation code: (1) facilitated the calibration process by providing a quantitative assessment of the model's ability to match disparate observed data types; and (2) allowed assessment of the influence of observed targets on the calibration process. The model calibration required the use of a 'universal' parameter estimation code in order to include all types of observations in the objective function. The methods described in this paper help address issues of watershed complexity and non-uniqueness common to deterministic watershed models. ?? 2005 Elsevier B.V. All rights reserved.

Estimation of water storage changes in small endorheic lakes in Burabay National Nature Park (Northern Kazakhstan, Central Asia); the effect of climate change and anthropogenic influences

NASA Astrophysics Data System (ADS)

Yapiyev, Vadim; Sagintayev, Zhanay; Verhoef, Anne; Samarkhanov, Kanat; Jumassultanova, Saltanat

2017-04-01

Both climate change and anthropogenic activities contribute to deterioration of terrestrial water resources and ecosystems worldwide. It has been observed in recent decades that water-limited steppe regions of Central Asia are among ecosystems found to exhibit enhanced responses to climate variability. In fact, the largest share of worldwide net loss of permanent water extent is geographically concentrated in the Central Asia and Middle East regions attributed to both climate variability/change and human activities impacts. We used a digital elevation model, digitized bathymetry maps and high resolution Landsat images to estimate the areal water cover extent and volumetric storage changes in small terminal lakes in Burabay National Nature Park (BNNP), located in Northern Central Asia, for the period 2000-2016. Based on the analysis of long-term climatic data from meteorological stations, hydrometeorological network observations as well as regional climate model projections we evaluate the impacts of past thirty years and future climatic conditions on the water balance of BNNP lake catchments. The anthropogenic water consumption was estimated based on data collected at a local water supply company and regulation authorities. One the one hand historical in-situ observations and future climate projections do not show a significant change in precipitation in BNNP. On the other hand both observations and the model demonstrate steadily rising air temperatures in the area. It is concluded that the long-term decline in water levels for most of these lakes can be largely attributed to climate change (but only via changes in air temperature, causing evaporation to exceed precipitation) and not to direct anthropogenic influences such as increased water withdrawals. In addition, the two largest lakes, showing the highest historical water level decline, do not have sufficient water drainage basin area to sustain water levels under increased evaporation rates.

First numerical ages from the northern lake Chapala shoreline, western Mexico, and their importance for palaeontology and archaeology

NASA Astrophysics Data System (ADS)

Kadereit, Annette; Dewitt, Regina; Terrazas, Alejandro; Stinnesbeck, Wolfgang; Zipf, Lars; Schukraft, Gerd

2017-04-01

Lake Chapala in the central-western Mexican state of Jalisco is the successor of the late-Miocene to early Pleistocene palaeo-lake Jalisco and is situated in an active neotectonic basin at approximately 1500 m above sea level. It presently covers an area of ca. 1100 km2 and represents Mexico's largest freshwater reservoir. As water depth reaches only a few meters the position of its shorelines has fluctuated substantially throughout the lake's history due to volcanic and tectonic activity as well as climate fluctuations. One of the more recently abandoned shorelines is preserved on the northern shoreline east of Ajijic at San Antonio Tlayacapan (SAT), where sand and silt deposits crop out at the present waterline. The beach sediments at SAT are famous for their fossils of late Wisconsian age (e.g. ground sloths, gomphotheriids), but also host human osteological remains, which are now housed in the Museo de Paleontología de Guadalajara, in the state capital. Numeric dating of sediments from Lake Chapala has proven to be exceedingly difficult as bones are heavily mineralized by Fe-Mn-oxides. In addition, input of ancient carbon exists from hydrothermal sources deep underneath the lake bottom and its distribution throughout the lake-water body, with currents driven by easterly winds and respective counter-currents, leading to age inversions for 14C-dating (Zárate-del-Valle et al. 2011). As 14C radiometric methods are thus shown to be problematic we here tested the possibility of optical stimulated luminescence (OSL) dating. Diverse tests showed that the samples were not adequate for coarse-grain quartz dating or post infrared stimulated (post-IR) blue-light stimulated (BLSL) dating of polymineral fine grains. The blue emission band of the infrared stimulated luminescence (IRSL) signal of the natural samples has been proven to be quite dim, so that a single aliquot regeneration (SAR) protocol (Murray & Wintle 2000) was not suitable. Finally, we applied a traditional

Crystalline rocks of the Strawberry Lake area, Front Range, Colorado

USGS Publications Warehouse

Young, Edward J.

1991-01-01

This report is a petrographic and geochemical study of the bedrock and a petrologic discussion based on felsic-mafic and silica-saturation ratios of the Strawberry Lake area. This volume is published as chapters A and B. These chapters are not available separatelyThe Strawberry lake area lies between the Continental Divide and Granby, Colorado, just north of Tabernash. It is underlain by Proterozoic rocks composed of biotite gneiss and two plutons-Boulder Creek Granodiorite of the Routt Plutonic Suite and Silver Plume Granite of the Berthoud Plutonic Suite. Relict enclaves of biotite gneiss are not uncommon in the Boulder Creek Granodiorite, in the Silver Plume Granite, and in the granitic enclaves in the biotite gneiss. Granitic and mafic enclaves in the Boulder Creek Granodiorite, granitic enclaves in the Silver Plume Granite and in the biotite gneiss, and a Tertiary andesite porphyry dike complete the rock types.

Natural Environmental Hazards Reflected in High-Altitude Patagonian Lake Sediments (lake Caviahue, Argentina)

NASA Astrophysics Data System (ADS)

Müller, Anne; Scharf, Burkhard; von Tümpling, Wolf; Pirrung, Michael

2009-03-01

Two 6-m long sediment cores drilled in the two basins of Lake Caviahue give new evidence of the impact of natural hazards such as ash fallouts linked to nearby volcanic eruptions in the ecologically sensitive environment of the high-altitude region of the Argentinan Patagonian Andes. The two cores show distinct signals of changes in autochthonous productivity and terrigenous input into the lake from ash fallout as well as from river load and shore erosion. Multiproxy records of the sediments indicate whether these changes can be related to volcanic activity. High values of magnetic susceptibility in the cores reflect periods of basaltic ash fallouts during eruptions of the nearby Copahue Volcano. The southern basin is located in the prevalent direction of ash fallouts and has been affected by these volcanic inputs more intensely than the northern basin of the lake. In contrast, sedimentation and authochthonous productivity in the northern basin are strongly affected by fluvial inputs such as suspended river load and acidic stream waters.

Natural Environmental Hazards Reflected in High-Altitude Patagonian Lake Sediments (Lake Caviahue, Argentina)

NASA Astrophysics Data System (ADS)

Mueller, A.; Pirrung, M.; Scharf, B.; von Tuempling, W.

2007-05-01

Two 6-m long sediment cores drilled in the two basins of Lake Caviahue give new evidence of the impact of natural hazards such as ash fallouts linked to nearby volcanic eruptions in the ecologically sensitive environment of the high-altitude region of the Argentinan Patagonian Andes. The two cores show distinct signals of changes in autochthonous productivity and terrigenous input into the lake from ash fallout, river load and shore erosion. Multiproxy records of the sediments indicate whether these changes can be related to volcanic activity. High values of magnetic susceptibility in the cores reflect periods of basaltic ash fallouts during eruptions of the nearby Copahue volcano. The southern basin is located in the prevalent direction of ash fallouts and has been affected by these volcanic inputs more intensely than the northern basin of the lake. In contrast, sedimentation and authochthonous productivity in the northern basin are strongly affected by fluvial inputs such as suspended river load and acidic stream waters.

Study on the relationship between the lake area variations of Qinghai-Tibetan Plateau and the corresponding climate change in their basins

NASA Astrophysics Data System (ADS)

Guozhuang, Shen; Jingjuan, Liao; Huadong, Guo; Yingkui, Li

2014-03-01

Qinghai-Tibetan Plateau is the largest lake area in China, with a total area of existing lakes of 36,900km2, accounting for 52% of the total lake area of China. Lakes on the Tibetan Plateau play critical roles in the water cycle and ecological and environment systems of the Plateau. The global trend of warming up is increasing obviously, which has led to major changes in the climate conditions in China, even in the world. Whereas, when they analyse the relationship they just use the weather station's recording data, without any spatial analysis of the climate data. Here, we will do some researches on the relationship between the 10 selected lakes' area variation and the corresponding climate change in their drainage basin and discuss how the lakes changes in recent 40 years using the climate data processed using the spatial kriging. Thus, the drainage area can be taken into account and a real relationship can be pointed out. In order to study the relationship, Landsat MSS data, Landsat TM, Landsat ETM images, the topographic map have been collected to extract the variation of lake area. The 131 weather stations climate data, including precipitation, temperature, sun shine duration, evaporation are chosen to study the relationship. After extraction of the area of the lakes, a multivariate statistical analysis method was used to test the relationship between the area of the lakes and the global climate change, including the change of the temperature, the precipitation, and other factors. The variation of lakes in Qinghai-Tibetan Plateau is related to the mean temperature, the precipitation and saturation vapour pressure. But the frozen soil may affect the lake area variation to some extent.

Distribution and abundance of larval fish in the nearshore waters of western Lake Huron

USGS Publications Warehouse

O'Gorman, Robert

1983-01-01

Ichthyoplankton was collected at 17 nearshore (bottom depth ≥5 m but ≤10 m) sites in western Lake Huron during 1973–75 with a 0.5-m net of 351-micron mesh towed at 99 m/min. Larvae of rainbow smelt (Osmerus mordax) dominated late spring and early summer catches and larvae of alewives (Alosa pseudoharengus) the midsummer catches. Larval yellow perch (Perca flavescens) were caught in early summer but were rarely the dominant species. The time of spawning and hatching, and thus occurrence of larvae, differed between areas but was less variable for alewives than for yellow perch. The appearance of larvae in Saginaw Bay was followed successively by their appearance in southern, central, and northern Lake Huron. Rainbow smelt were most abundant in northern Lake Huron and yellow perch and alewives in inner Saginaw Bay. Densities of either rainbow smelt or alewives occasionally exceeded 1/m3, whereas those of yellow perch never exceeded 0.1/m3. Abundance of alewives was usually highest 1 to 3 m beneath the surface and that of rainbow smelt 2 to at least 6 m beneath the surface. Important nursery areas of rainbow smelt were in bays and off irregular coastlines and those of yellow perch were in bays. All nearshore waters seemed equally important as nursery areas of alewives.

Evolution of supra-glacial lakes across the Greenland Ice Sheet

NASA Astrophysics Data System (ADS)

Sundal, A. V.; Shepherd, A.; Nienow, P.; Hanna, E.; Palmer, S.; Huybrechts, P.

2009-04-01

We have used 268 cloud-free Moderate-resolution Imaging Spectroradiometer (MODIS) images spanning the 2003 and 2005-2007 melt seasons to study the seasonal evolution of supra-glacial lakes in three different regions of the Greenland Ice Sheet. Lake area estimates were obtained by developing an automated classification method for their identification based on 250 m resolution MODIS surface reflectance observations. Widespread supra-glacial lake formation and drainage is observed across the ice sheet, with a 2-3 weeks delay in the evolution of total supra-glacial lake area in the northern areas compared to the south-west. The onset of lake growth varies by up to one month inter-annually, and lakes form and drain at progressively higher altitudes during the melt season. A correlation was found between the annual peak in total lake area and modelled annual runoff across all study areas. Our results indicate that, in a future warmer climate (Meehl et al., 2007), Greenland supra-glacial lakes can be expected to form at higher altitudes and over a longer time period than is presently the case, expanding the area and time period over which connections between the ice sheet surface and base may be established (Das et al., 2008) with potential consequences for ice sheet discharge (Zwally et al., 2002). Das, S., Joughin, M., Behn, M., Howat, I., King, M., Lizarralde, D., & Bhatia, M. (2008). Fracture propagation to the base of the Greenland Ice Sheet during supra-glacial lake drainage. Science, 5877, 778-781. Meehl, G.A., Stocker, T.F., Collins W.D., Friedlingstein, P., Gaye, A.T., Gregory, J.M., Kitoh, A., Knutti, R., Murphy, J.M., Noda, A., Raper, S.C.B., Watterson, I.G., Weaver, A.J. & Zhao, Z.C. (2007). Global Climate Projections. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor

Length-weight relationship of northern pike, Esox lucius, from East Harbor, Ohio

USGS Publications Warehouse

Brown, Edward H.; Clark, Clarence F.

1965-01-01

The northern pike is one of Ohio's largest game fish but is well known to comparatively few anglers. Large numbers of the big fish spawn in the Ohio marshes adjacent to Lake Erie. Movements related to spawning reach a peak in late March or early April. Later the spawning population disperses and is seldom represented in catches by experimental gear or by anglers. The short period of availability was used to obtain life history information in March of 1951 through 1953. No comprehensive length-weight data for this species have previously been published from this area. East Harbor is a sandspit pond separated from Lake Erie by a large sand bar. Waters and fish populations of the harbor and lake can mix freely through a permanent connecting channel. The larger part of the 850 surface acres of the harbor is normally less than 8 feet deep. The male northern pike averaged 20.5 inches in length and ranged from 13.5 to 28.5 inches. The conspicuously larger females averaged 26.0 inches and ranged from 15.5 to 37.5 inches.

Calculation of area and volume for the south part of Great Salt Lake, Utah

USGS Publications Warehouse

Baskin, Robert L.

2005-01-01

The U.S. Geological Survey, in cooperation with the Utah Department of Natural Resources, Division of Wildlife Resources, collected bathymetric data for the south part of Great Salt Lake during 2002-04 using a single-beam, high-definition fathometer and real-time differential global positioning system. About 7.6 million depth measurements were collected along more than 930 miles (1,690 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 508,000 acres (2,056 square kilometers) and a maximum volume of about 9,257,000 acre-feet (11.42 cubic kilometers) at a water-surface altitude of 4,200 feet (1,280 meters). Minimum water-surface altitude of the south part of Great Salt Lake is just below 4,167 feet (1,279 meters) in the area just south of the Union Pacific railroad causeway halfway between Promontory Point and the western edge of the lake. At this altitude, and continuing up to about 4,176 feet (1,279 meters), the south part of the lake is separated into two areas by a ridge extending from Promontory Point to Hat Island. Calculations for area and volume are based on a low altitude of 4,167 feet (1,279 meters) to a high altitude of 4,200 feet (1,280 meters).

36 CFR 7.48 - Lake Mead National Recreation Area.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Lake Mead National Recreation Area. 7.48 Section 7.48 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE... watercraft at a speed in excess of flat wake speed within 200 feet of any beach occupied by bathers, boats at...

36 CFR 7.48 - Lake Mead 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 Mead National Recreation Area. 7.48 Section 7.48 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE... watercraft at a speed in excess of flat wake speed within 200 feet of any beach occupied by bathers, boats at...

36 CFR 7.48 - Lake Mead National Recreation Area.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Lake Mead National Recreation Area. 7.48 Section 7.48 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE... watercraft at a speed in excess of flat wake speed within 200 feet of any beach occupied by bathers, boats at...

36 CFR 7.48 - Lake Mead 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 Mead National Recreation Area. 7.48 Section 7.48 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE... watercraft at a speed in excess of flat wake speed within 200 feet of any beach occupied by bathers, boats at...

36 CFR 7.48 - Lake Mead National Recreation Area.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Lake Mead National Recreation Area. 7.48 Section 7.48 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE... watercraft at a speed in excess of flat wake speed within 200 feet of any beach occupied by bathers, boats at...

Geophysical Investigation of a Thermokarst Lake Talik in Continuous Permafrost

NASA Astrophysics Data System (ADS)

Creighton, A.; Parsekian, A.; Arp, C. D.; Jones, B. M.; Babcock, E.; Bondurant, A. C.

2016-12-01

On the Arctic Coastal Plain (ACP) of northern Alaska, shallow thermokarst lakes cover up to 25% of the landscape. These lakes occupy depressions created by the subsidence of thawed, ice-rich permafrost. Areas of unfrozen sediment, or taliks, can form under lakes that have a mean annual bottom temperature greater than 0°C. The geometry of these taliks, as well as the processes that create them, are important for understanding interactions between surface water, groundwater, and carbon cycling. Non-invasive geophysical methods are a useful means to study talik sediments as borehole studies yield few data points, and the contrast between unfrozen and frozen sediments is an ideal geophysical target. To study talik configuration associated with an actively expanding thermokarst lake, we conducted a geophysical transect across Peatball Lake. This lake has an estimated initiation age of 1400 calendar years BP. Over the past 60 years, lake surface area has increased through thermal and mechanical shoreline erosion. A talik of previously unknown thickness likely exists below Peatball Lake. We conducted a transect of transient electromagnetic soundings across the lake extending into the surrounding terrestrial environment. Since permafrost has relatively high resistivity compared to talik sediments, the interpreted electrical structure of the subsurface likely reflects talik geometry. We also conducted nuclear magnetic resonance soundings at representative locations along the transect. These measurements can provide data on sub-lake sediment properties including water content. Together, these measurements resolve the talik structure across the lake transect and showed evidence of varying talik thicknesses from the lake edge to center. These is no evidence of a talik at the terrestrial control sites. These results can help constrain talik development models and thus provide insight into Arctic and permafrost processes in the face of a changing climate.

Diet and habitat use by age-0 deepwater sculpins in northern Lake Huron, Michigan and the Detroit River

USGS Publications Warehouse

Roseman, Edward F.

2014-01-01

Deepwater sculpins (Myoxocephalus thompsonii) are an important link in deepwater benthic foodwebs of the Great Lakes. Little information exists about deepwater sculpin spawning habits and early life history ecology due to difficulty in sampling deep offshore habitats. Larval and age-0 deepwater sculpins collected in northern Lake Huron and the Detroit River during 2007 were used to improve our understanding of their habitat use, diet, age, and growth. Peak larval density reached 8.4/1000 m3 in the Detroit River during April and was higher than that in Lake Huron. Offshore bottom trawls at DeTour and Hammond Bay first collected benthic age-0 deepwater sculpins in early September when fish were ≥ 25 mm TL. Otolith analysis revealed that hatch dates for pelagic larvae occurred during late March and larvae remained pelagic for 40 to 60 days. Diet of pelagic larvae (10–21 mm TL) was dominated by calanoid copepods at all sample locations. Diets of benthic age-0 fish varied by location and depth: Mysis and chironomids were prevalent in fish from Hammond Bay and the 91 m site at DeTour, but only chironomids were found in fish from the 37 m DeTour site. This work showed that nearshore epilimnetic sites were important for pelagic larvae and an ontogenetic shift from pelagic planktivore to benthivore occurred at about 25 mm TL in late summer. Age analysis showed that larvae remained pelagic long enough to be transported through the St. Clair–Detroit River system, Lake Erie, and the Niagara River, potentially contributing to populations in Lake Ontario.

What are northern hardwoods?

Treesearch

Richard M. Godman

1992-01-01

The term "northern hardwoods" was used in the early 1900's to separate the hardwoods of the northern region from those growing in the South. With continued usage in the North the term now represents all dense hardwood species both in the Lake States and Northeast. Unfortunately, this has complicated describing and applying silvicultural practices for...

Development of an Interactive Shoreline Management Tool for the Lower Wood River Valley, Oregon - Phase I: Stage-Volume and Stage-Area Relations

USGS Publications Warehouse

Haluska, Tana L.; Snyder, Daniel T.

2007-01-01

This report presents the parcel and inundation area geographic information system (GIS) layers for various surface-water stages. It also presents data tables containing the water stage, inundation area, and water volume relations developed from analysis of detailed land surface elevation derived from Light Detection and Ranging (LiDAR) data recently collected for the Wood River Valley at the northern margin of Agency Lake in Klamath County, Oregon. Former shoreline wetlands that have been cut off from Upper Klamath and Agency Lakes by dikes might in the future be reconnected to Upper Klamath and Agency Lakes by breaching the dikes. Issues of interest associated with restoring wetlands in this way include the area that will be inundated, the volume of water that may be stored, the change in wetland habitat, and the variation in these characteristics as surface-water stage is changed. Products from this analysis can assist water managers in assessing the effect of breaching dikes and changing surface-water stage. The study area is in the approximate former northern margins of Upper Klamath and Agency Lakes in the Wood River Valley.

Limnology and fish ecology of sockeye salmon nursery lakes of the world

USGS Publications Warehouse

Hartman, Wilbur L.; Burgner, R.L.

1972-01-01

Many important, recently glaciated oligotrophic lakes that lie in coastal regions around the northern rim of the Pacific Ocean produce anadromous populations of sockeye salmon, Oncorhynchus nerka. This paper describes the limnology and fish ecology of two such lakes in British Columbia, five in Alaska, and one in Kamchatka. Then we discuss the following general topics: the biogenic eutrophication of nursery lakes from the nutrients released from salmon carcasses wherein during years of highest numbers of spawners, lake phosphate balances in Lakes Babine, Iliamna, and Dalnee are significantly affected; the use of nursery lakes by young sockeye that reveals five patterns related to size and configuration of lake basins and the distribution of spawning areas; the interactions between various life history stages of sockeye salmon and such resident predators, competitors, and prey as Arctic char, lake trout, Dolly Varden, cutthroat trout, lake whitefish, pygmy whitefish, pond smelt, sticklebacks, and sculpins; the self-regulation of sockeye salmon abundance in these nursery lakes as controlled by density-dependent processes; the interrelations between young sockeye salmon biomass and growth rates, and zooplankton abundance in Babine Lake; and finally, the diel, vertical, pelagial migratory behavior of young sockeye in Babine Lake and the new hypothesis dealing with bioenergetic conservation.

Trophic transfer of persistent organic pollutants through a pelagic food web: The case of Lake Como (Northern Italy).

PubMed

Mazzoni, Michela; Boggio, Emanuela; Manca, Marina; Piscia, Roberta; Quadroni, Silvia; Bellasi, Arianna; Bettinetti, Roberta

2018-05-30

Despite DDT and PCB having been banned for about 40 years, they are still detectable in the environment. In the present research we specifically investigated the trophic transfer of these organochlorine contaminants (OC) through a pelagic food web of a deep lake in Northern Italy (Lake Como) over time. Zooplankton and fish were sampled each season of a year and OC concentrations and the carbon and nitrogen isotopic ratios were measured. By using stable isotopes, the direct trophic relationship between pelagic zooplankton and zooplanktivorous fish was confirmed for Alosa agone only in summer. Based on this result, the biomagnification factor normalized on the trophic level (BMF TL ) for organic contaminants was calculated. BMF TL values were within the range 0.9-1.9 for DDT isomers and 1.6-4.9 for some PCB congeners (PCB 95, PCB 101, PCB 149, PCB 153, PCB 138 - present both in zooplankton and in fish and representing >60% of the PCB contamination), confirming the biomagnification of these compounds in one of the two zooplanktivorous fish species of the lake. Copyright © 2018. Published by Elsevier B.V.

Northern Mediterranean climate since the Middle Pleistocene: a 637 ka stable isotope record from Lake Ohrid (Albania/Macedonia)

NASA Astrophysics Data System (ADS)

Lacey, Jack H.; Leng, Melanie J.; Francke, Alexander; Sloane, Hilary J.; Milodowski, Antoni; Vogel, Hendrik; Baumgarten, Henrike; Zanchetta, Giovanni; Wagner, Bernd

2016-03-01

, and the Holocene. Our results provide new evidence for long-term climate change in the northern Mediterranean region, which will form the basis to better understand the influence of major environmental events on biological evolution within Lake Ohrid.

Mercury Enrichment in Sediments of the Coastal Area of Northern Latium, Italy.

PubMed

Scanu, Sergio; Piazzolla, Daniele; Frattarelli, Francesco Manfredi; Mancini, Emanuele; Tiralongo, Francesco; Brundo, Maria Violetta; Tibullo, Daniele; Pecoraro, Roberta; Copat, Chiara; Ferrante, Margherita; Marcelli, Marco

2016-05-01

The purpose of this study was to evaluate the extent of the Hg geochemical anomaly arising in the Amiata and Tolfa complex to the coastal area of northern Latium and to examine the possible influence on this area by the Mignone River, and by the small coastal basins, which are characterized by both previous mining activities and decades of past industrial impact. The results confirm the extension of the anomaly of concentrations of Hg in the coastal area of northern Latium, with the northern sector influenced by the contributions of the Fiora and Mignone Rivers and the southern sector influenced by the contributions of minor basins. The results show high values of the Adverse Effect Index throughout the considered area and highlight the need for further investigation in order to assess the impact of human activities on the present and past values of Hg in marine sediments.

Seasonal and Latitudinal Variations in Dissolved Methane from 42 Lakes along a North-South Transect in Alaska

NASA Astrophysics Data System (ADS)

Sepulveda-Jauregui, A.; Walter Anthony, K. M.; Martinez-Cruz, K. C.; Anthony, P.; Thalasso, F.

2013-12-01

Armando Sepulveda-Jauregui,* Katey M. Walter Anthony,* Karla Martinez-Cruz,* ** Peter Anthony,* and Frederic Thalasso**. * Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, Alaska. ** Biotechnology and Bioengineering Department, Cinvestav, Mexico city, D. F., Mexico. Northern lakes are important reservoirs and sources to the atmosphere of methane (CH4), a potent greenhouse gas. It is estimated that northern lakes (> 55 °N) contribute about 20% of the total global lake methane emissions, and that emissions from these lakes will increase with climate warming. Temperature rise enhances methane production directly by providing the kinetic energy to methanogenesis, and indirectly by supplying organic matter from thawing permafrost. Warmer lakes also store less methane since methane's solubility is inversely related to temperature. Alaskan lakes are located in three well-differentiated permafrost classes: yedoma permafrost with high labile carbon stocks, non-yedoma permafrost with lower carbon stocks, and areas without permafrost, also with generally lower carbon stocks. We sampled dissolved methane from 42 Alaskan lakes located in these permafrost cover classes along a north-south Alaska transect from Prudhoe Bay to the Kenai Peninsula during open-water conditions in summer 2011. We sampled 26 of these lakes in April, toward the end of the winter ice-covered period. Our results indicated that the largest dissolved methane concentrations occurred in interior Alaska thermokarst lakes formed in yedoma-type permafrost during winter and summer, with maximal concentrations of 17.19 and 12.76 mg L-1 respectively. In these lakes, emission of dissolved gases as diffusion during summer and storage release in spring were 18.4% and 17.4% of the annual emission budget, while ebullition (64.2 %) comprised the rest. Dissolved oxygen was inversely correlated with dissolved methane concentrations in both seasons; the

Lake Mead, NV

NASA Image and Video Library

1973-06-22

SL2-03-192 (22 June 1973) --- Lake Mead, Nevada, (36.0N, 114.5E) where the water from the Colorado River empties after it's 273 mile journey through the Grand Canyon of Arizona is the subject of this photo. Other features of interest are Hoover Dam on the south shore of Lake Mead where cheap hydroelectric power is secondary to the water resources made available in this northern desert region and the resort city of Las Vegas, just to the west of Lake Mead. In this harsh desert environment, color infrared photography readily penetrates haze, detects and portrays vegetation as shades of red. Photo credit: NASA

Model Estimate of Pan-Arctic Lakes and Wetlands Methane Emissions and Their Future Climate Response

NASA Astrophysics Data System (ADS)

Chen, X.; Bohn, T. J.; Maksyutov, S. S.; Lettenmaier, D. P.

2013-12-01

Lakes and wetlands are important sources of the greenhouse gas CH4, whose emission rate is sensitive to climate. The northern high latitudes, which are especially susceptible to climate change, contain about 50% of the world's lakes and wetlands. Given predicted changes in the climate of this region over the next century (IPCC AR5 scenarios), there is concern about a possible positive feedback resulting from methane emissions from the region's wetlands and lakes. To study the climate response of emissions from northern high latitude lakes and wetlands, we employed a large-scale hydrology and carbon cycling model (Variable Infiltration Capacity model; VIC) over the Pan-Arctic domain, which was linked to an atmospheric model (Japan's National Institute of Environmental Studies transport model; NIES TM). In particular, the VIC model simulates the land surface hydrology and carbon cycling across a dynamic lake-wetland continuum, while NIES TM models the atmospheric mixing and 3-dimension transport of methane emitted. The VIC model includes a distributed wetland water table scheme, which accounts for microtopography around the lakes and simulates variations in inundated area that are calibrated to match a passive microwave based inundation product. Per-unit-area carbon uptake and methane emissions at the land surface have been calibrated using extensive in situ observations at West Siberia. Also, the atmospheric methane concentration from this linked model run was verified for the recent 5 years with satellite observations from Aqua's Atmospheric Infrared Sounder (AIRS) and Envisat's Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) instruments. Using RCP4.5 and RCP8.5 future climate scenarios, we examine CH4 emissions from high latitude lakes and wetlands, as well as their net greenhouse warming potential, over the next 3 centuries across the Pan-Arctic domain. We also assess relative uncertainties in emissions from each of the sources.

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.

Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

USGS Publications Warehouse

Jones, Perry M.; Trost, Jared J.; Erickson, Melinda L.

2016-10-19

OverviewThis study assessed lake-water levels and regional and local groundwater and surface-water exchanges near northeast Twin Cities Metropolitan Area lakes applying three approaches: statistical analysis, field study, and groundwater-flow modeling.  Statistical analyses of lake levels were completed to assess the effect of physical setting and climate on lake-level fluctuations of selected lakes. A field study of groundwater and surface-water interactions in selected lakes was completed to (1) estimate potential percentages of surface-water contributions to well water across the northeast Twin Cities Metropolitan Area, (2) estimate general ages for waters extracted from the wells, and (3) assess groundwater inflow to lakes and lake-water outflow to aquifers downgradient from White Bear Lake.  Groundwater flow was simulated using a steady-state, groundwater-flow model to assess regional groundwater and surface-water exchanges and the effects of groundwater withdrawals, climate, and other factors on water levels of northeast Twin Cities Metropolitan Area lakes.

Extreme events, trends, and variability in Northern Hemisphere lake-ice phenology (1855-2005)

USGS Publications Warehouse

Benson, Barbara J.; Magnuson, John J.; Jensen, Olaf P.; Card, Virginia M.; Hodgkins, Glenn; Korhonen, Johanna; Livingstone, David M.; Stewart, Kenton M.; Weyhenmeyer, Gesa A.; Granin, Nick G.

2012-01-01

Often extreme events, more than changes in mean conditions, have the greatest impact on the environment and human well-being. Here we examine changes in the occurrence of extremes in the timing of the annual formation and disappearance of lake ice in the Northern Hemisphere. Both changes in the mean condition and in variability around the mean condition can alter the probability of extreme events. Using long-term ice phenology data covering two periods 1855–6 to 2004–5 and 1905–6 to 2004–5 for a total of 75 lakes, we examined patterns in long-term trends and variability in the context of understanding the occurrence of extreme events. We also examined patterns in trends for a 30-year subset (1975–6 to 2004–5) of the 100-year data set. Trends for ice variables in the recent 30-year period were steeper than those in the 100- and 150-year periods, and trends in the 150-year period were steeper than in the 100-year period. Ranges of rates of change (days per decade) among time periods based on linear regression were 0.3−1.6 later for freeze, 0.5−1.9 earlier for breakup, and 0.7−4.3 shorter for duration. Mostly, standard deviation did not change, or it decreased in the 150-year and 100-year periods. During the recent 50-year period, standard deviation calculated in 10-year windows increased for all ice measures. For the 150-year and 100-year periods changes in the mean ice dates rather than changes in variability most strongly influenced the significant increases in the frequency of extreme lake ice events associated with warmer conditions and decreases in the frequency of extreme events associated with cooler conditions.

Late Quaternary landscape development at the margin of the Pomeranian phase (MIS 2) near Lake Wygonin (Northern Poland)

NASA Astrophysics Data System (ADS)

Hirsch, Florian; Schneider, Anna; Nicolay, Alexander; Błaszkiewicz, Mirosław; Kordowski, Jarosław; Noryskiewicz, Agnieszka M.; Tyszkowski, Sebastian; Raab, Alexandra; Raab, Thomas

2015-04-01

In Central Europe, Late Quaternary landscapes experienced multiple phases of geomorphologic activity. In this study,we used a combined geomorphological, pedological, sedimentological and palynological approach to characterize landscape development after the Last Glacial Maximum (LGM) near Lake Wygonin in Northern Poland. The pedostratigraphical findings from soil pits and drillings were extrapolated using ground-penetrating radar (GPR) and electric resistivity tomography (ERT). During the Pomeranian phase, glacial and fluvioglacial processes dominated the landscape near Lake Wygonin. At the end of the glacial period, periglacial processes became relevant and caused the formation of ventifacts and coversands containing coated sand grains. At approximately 15,290-14,800 cal yr BP, a small pond formed in a kettle hole (profile BWI2). The lacustrine sediments lack eolian sand components and therefore indicate the decline of eolian processes during that time. The increase of Juniperus and rock-rose (Helianthemum) in the pollen diagram is a prominent marker of the Younger Dryas. At the end of the Younger Dryas, a partial reshaping of the landscape is indicated by abundant charcoal fragments in disturbed lake sediments. No geomorphologic activity since the beginning of the Holocene is documented in the terrestrial and wetland archives. The anthropogenic impact is reflected in the pollen diagram by the occurrence of rye pollen grains (Cerealia type, Secale cereale) and translocated soil sediments dated to 1560-1410 cal yr BP, proving agricultural use of the immediate vicinity. With the onset of land use, gully incision and the accumulation of colluvial fans reshaped the landscape locally. Since 540-460 cal yr BP, further gully incision in the steep forest tracks has been associated with the intensification of forestry. Outside of the gully catchments, the weakly podzolized Rubic Brunic Arenosols show no features of Holocene soil erosion. Reprinted from CATENA, Volume 124

Zooplankton communities and Bythotrephes longimanus in lakes of the montane region of the northern Alps

PubMed Central

Horváth, Zsófia; Vad, Csaba F.; Preiler, Christian; Birtel, Julia; Matthews, Blake; Ptáčníková, Radka; Ptáčník, Robert

2017-01-01

Abstract Lakes in the Alps represent a considerable fraction of nutrient-poor lakes in Central Europe, with unique biodiversity and ecosystem properties. Although some individual lakes are well studied, less knowledge is available on large-scale patterns essential to general understanding of their functioning. Here, we aimed to describe crustacean zooplankton communities (Cladocera, Copepoda) and identify their environmental drivers in the pelagic zone of 54 oligotrophic lakes in the montane region of the Alps (400–1200 m) in Austria, Germany, and Switzerland, covering a spatial scale of 650 km. Moreover, we aimed to provide data on the distribution and ecological requirements of the North American invader Bythotrephes longimanus in its Central European native range. Communities were mainly dominated by widespread species typical of lowland habitats, and only a few true specialists of oligotrophic alpine lakes were present. The most frequent taxa were the Daphnia longispina complex and Eudiaptomus gracilis, with 48 and 45 occurrences, respectively. Species richness decreased with altitude and increased with lake area. The main structuring factors of community composition were chlorophyll a concentration and depth, which drove an apparent separation of mesotrophic and oligotrophic communities. Bythotrephes had 13 occurrences, showing a preference for deep oligotrophic lakes. Its presence was not coupled with lower crustacean species richness, as was repeatedly observed in North America. Additionally, it frequently co-occurred with the other large predatory cladoceran, Leptodora kindtii. B. longimanus might be considered a truly montane species in Central Europe, given its absence in lowland and alpine lakes. PMID:28824797

Zooplankton communities and Bythotrephes longimanus in lakes of the montane region of the northern Alps

PubMed Central

Horváth, Zsófia; Vad, Csaba F.; Preiler, Christian; Birtel, Julia; Matthews, Blake; Ptáčníková, Radka; Ptacnik, Robert

2017-01-01

Lakes in the Alps represent a considerable fraction of nutrient-poor lakes in Central Europe, with unique biodiversity and ecosystem properties. Although some individual lakes are well-studied, less knowledge is available on large-scale patterns essential to generalise the understanding of their functioning. Here, we aimed to describe crustacean zooplankton communities (Cladocera, Copepoda) and identify their environmental drivers in the pelagic zone of 54 oligotrophic lakes in the montane region of the Alps (400–1200 m) in Austria, Germany, and Switzerland, covering a spatial scale of 650 km. Moreover, we aimed to provide data on the distribution and ecological requirements of the North American invader Bytotrephes longimanus in its Central European native range. Communities were mainly dominated by widespread species typical of lowland habitats, and only a few true specialists of oligotrophic alpine lakes were present. The most frequent taxa were the Daphnia longispina complex and Eudiaptomus gracilis, with 48 and 45 occurrences, respectively. Species richness decreased with altitude and increased with lake area. The main structuring factors of community composition were chlorophyll a concentration and depth, which drove an apparent separation of mesotrophic and oligotrophic communities. Bytotrephes had 13 occurrences, showing a preference for deep oligotrophic lakes. Its presence was not coupled with lower crustacean species richness as it was repeatedly observed in North America. Additionally, it frequently co-occurred with the other large predatory cladoceran, Leptodora kindtii. B. longimanus might be considered a truly montane species in Central Europe, given its absence in lowland and alpine lakes. PMID:28649318

History of human activity in last 800 years reconstructed from combined archive data and high-resolution analyses of varved lake sediments from Lake Czechowskie, Northern Poland

NASA Astrophysics Data System (ADS)

Słowiński, Michał; Tyszkowski, Sebastian; Ott, Florian; Obremska, Milena; Kaczmarek, Halina; Theuerkauf, Martin; Wulf, Sabine; Brauer, Achim

2016-04-01

The aim of the study was to reconstruct human and landscape development in the Tuchola Pinewoods (Northern Poland) during the last 800 years. We apply an approach that combines historic maps and documents with pollen data. Pollen data were obtained from varved lake sediments at a resolution of 5 years. The chronology of the sediment record is based on varve counting, AMS 14C dating, 137Cs activity concentration measurements and tephrochronology (Askja AD 1875). We applied the REVEALS model to translate pollen percentage data into regional plant abundances. The interpretation of the pollen record is furthermore based on pollen accumulation rate data. The pollen record and historic documents show similar trends in vegetation development. During the first phase (AD 1200-1412), the Lake Czechowskie area was still largely forested with Quercus, Carpinus and Pinus forests. Vegetation was more open during the second phase (AD 1412-1776), and reached maximum openness during the third phase (AD 1776-1905). Furthermore, intensified forest management led to a transformation from mixed to pine dominated forests during this period. Since the early 20th century, the forest cover increased again with dominance of the Scots pine in the stand. While pollen and historic data show similar trends, they differ substantially in the degree of openness during the four phases with pollen data commonly suggesting more open conditions. We discuss potential causes for this discrepancy, which include unsuitable parameters settings in REVEALS and unknown changes in forest structure. Using pollen accumulation data as a third proxy record we aim to identify the most probable causes. Finally, we discuss the observed vegetation change in relation the socio-economic development of the area. This study is a contribution to the Virtual Institute of Integrated Climate and Landscape Evolution Analysis - ICLEA- of the Helmholtz Association and National Science Centre, Poland (grant No. 2011/01/B/ST10

20-year study of Barn Owl (Tyto alba) reproduction in northern Utah

Treesearch

Carl D. Marti

1997-01-01

I studied reproduction of the Barn Owl (Tyto alba) in northern Utah from 1977 through 1996 documenting 451 nesting attempts by at least 500 individuals. The study site was a narrow valley bounded by the Wasatch Mountains and the Great Salt Lake. This area was formerly shrubsteppe desert, but that community is now entirely supplanted by irrigated...

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.

Geology and ground-water resources of northern Mercer County, Pennsylvania

USGS Publications Warehouse

Schiner, G.R.; Kimmel, G.E.

1976-01-01

The Shenango and Stoneboro 15-minute quadrangles are in northwestern Pennsylvania and are about 60 miles north of Pitts burgh. These two quadrangles comprise the following 7%-minute quadrangles: Greenville West, Greenville East, Sharpsville, Fredonia, Hadley, New Lebanon, Jackson Center, and Sandy Lake. The area covered by the two quadrangles includes the northern two thirds of Mercer County and a small amount of adjoining southern Crawford County.

Organic geochemical investigations of the Dali Lake sediments in northern China: Implications for environment and climate changes of the last deglaciation in the East Asian summer monsoon margin

NASA Astrophysics Data System (ADS)

Fan, Jiawei; Xiao, Jule; Wen, Ruilin; Zhang, Shengrui; Wang, Xu; Cui, Linlin; Yamagata, Hideki

2017-06-01

Millennial-scale environment and climate changes in the East Asian summer monsoon margin during the last deglaciation are reconstructed by systematic studies on the characteristic of sedimentary organic matter from Dali Lake in northern China. Concurrent increases in the TOC and TN concentrations indicate increases in terrestrial organic matter and nutrient inputs to the lake and a development of terrestrial vegetation and phytoplankton productivity related to increases in regional temperature and precipitation. C/N ratios reflect changes in the proportions of terrestrial and aquatic organic matter. Decreases in both δ13Corg and δ15N values indicate increases in the isotopically lighter, terrestrial carbon and nitrogen inputs to the lake, due to increases in surface runoffs; while a sharp decrease in the δ15N value implies a significant weakening in the biological activities of nitrifying and amonifying bacteria, due to abrupt decrease in the water temperature. The geochemical data indicate that regional temperature and precipitation exhibited increasing trends from 15,000 to 12,350 cal yr BP; temperature decreased abruptly at 12,350 cal yr BP and then maintained a low level from 12,350 to 11,400 cal yr BP, precipitation decreased to a relatively low level from 12,350 to 11,400 cal yr BP; and both temperature and precipitation returned to increase after 11,400 cal yr BP. The climate change in the Dali Lake region during the last deglaciation corresponds, within age uncertainties, to the Bølling-Allerød (BA) warm phase and Younger Dryas (YD) cold reversal occurring over northern high latitudes. However, the gradual and mild increasing trends of regional temperature and precipitation during the BA warm period contrasts with the general cooling trend in northern high latitude temperature, implying a dominant influence from increases in the Northern Hemisphere summer insolation; while the slight decreases in regional precipitation relative to the rapid and

The predominance of young carbon in Arctic whole-lake CH4 and CO2 emissions and implications for Boreal yedoma lakes.

NASA Astrophysics Data System (ADS)

Elder, C.; Xu, X.; Walker, J. C.; Walter Anthony, K. M.; Pohlman, J.; Arp, C. D.; Townsend-Small, A.; Hinkel, K. M.; Czimczik, C. I.

2017-12-01

Lakes in Arctic and Boreal regions are hotspots for atmospheric exchange of the greenhouse gases CO2 and CH4. Thermokarst lakes are a subset of these Northern lakes that may further accelerate climate warming by mobilizing ancient permafrost C (> 11,500 years old) that has been disconnected from the active C cycle for millennia. Northern lakes are thus potentially powerful agents of the permafrost C-climate feedback. While they are critical for projecting the magnitude and timing these feedbacks from the rapidly warming circumpolar region, we lack datasets capturing the diversity of northern lakes, especially regarding their CH4contributions to whole-lake C emissions and their ability to access and mobilize ancient C. We measured the radiocarbon (14C) ages of CH4 and CO2 emitted from 60 understudied lakes and ponds in Arctic and Boreal Alaska during winter and summer to estimate the ages of the C sources yielding these gases. Integrated mean ages for whole-lake emissions were inferred from the 14C-age of dissolved gases sampled beneath seasonal ice. Additionally, we measured concentrations and 14C values of gases emitted by ebullition and diffusion in summer to apportion C emission pathways. Using a multi-sourced mass balance approach, we found that whole-lake CH4 and CO2 emissions were predominantly sourced from relatively young C in most lakes. In Arctic lakes, CH4 originated from 850 14C-year old C on average, whereas dissolved CO2 was sourced from 400 14C-year old C, and represented 99% of total dissolved C flux. Although ancient C had a minimal influence (11% of total emissions), we discovered that lakes in finer-textured aeolian deposits (Yedoma) emitted twice as much ancient C as lakes in sandy regions. In Boreal, yedoma-type lakes, CH4 and CO2 were fueled by significantly older sources, and mass balance results estimated CH4-ebullition to comprise 50-60% of whole-lake CH4 emissions. The mean 14C-age of Boreal emissions was 6,000 14C-years for CH4-C, and 2

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).

Geothermal constraints on enrichment of boron and lithium in salt lakes: An example from a river-salt lake system on the northern slope of the eastern Kunlun Mountains, China

NASA Astrophysics Data System (ADS)

Tan, Hongbing; Chen, Jun; Rao, Wenbo; Zhang, Wenjie; Zhou, Huifang

2012-06-01

Some rivers on the northern slope of the eastern Kunlun Mountains in the Qaidam Basin, China, show very high concentrations of boron and lithium. Correspondingly, the salt lakes fed by these rivers show an unusual enrichment of boron and lithium, and become an important economic resource. The origin of boron and lithium has long been debated. The aim of this study is to analyze the water chemistry and hydrogen and oxygen isotopic composition of river water to understand the unusual enrichment of boron and lithium in the salt lakes of the Qaidam Basin. Oxygen and hydrogen isotope data show that the source of river water in the winter and summer originates from the Kunlun Mountain ice and snow melt water, respectively. The water chemistry shows that boron and lithium contents are high but little variable with seasons in the Nalenggele River and Wutumeiren River waters. By contrast, other rivers have much lower lithium and boron contents. Moreover, the contents of B3+ and Li+ in the river loads or bed sands show little difference amongst the rivers. This indicates that removal by adsorption or input by surface rock weathering is not the main controlling factor of the B3+ and Li+ variation in the rivers. Rivers with high B3+ and Li+ content are chemically similar to geothermal waters in the Tibetan Plateau. In addition, the source area of the Nalenggele River is located in a collision zone of the Kunlun Mountains and Altun Mountains. Large and deep faults can serve as conduits for geothermal fluids. Thus, deep geothermal waters in the source area can easily migrate to the surface and discharge as springs feeding the rivers. They are an important source of B3+ and Li+ to the rivers. The abnormally high contents of B3+ and Li+ in the Nalenggele and Wutumeiren Rivers also suggest that the geothermal source area may be a future target for boron and lithium resources.

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...

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