Discovery of relict subglacial lakes and their geometry and mechanism of drainage

PubMed Central

Livingstone, Stephen J.; Utting, Daniel J.; Ruffell, Alastair; Clark, Chris D.; Pawley, Steven; Atkinson, Nigel; Fowler, Andrew C.

2016-01-01

Recent proxy measurements reveal that subglacial lakes beneath modern ice sheets periodically store and release large volumes of water, providing an important but poorly understood influence on contemporary ice dynamics and mass balance. This is because direct observations of how lake drainage initiates and proceeds are lacking. Here we present physical evidence of the mechanism and geometry of lake drainage from the discovery of relict subglacial lakes formed during the last glaciation in Canada. These palaeo-subglacial lakes comprised shallow (<10 m) lenses of water perched behind ridges orientated transverse to ice flow. We show that lakes periodically drained through channels incised into bed substrate (canals). Canals sometimes trend into eskers that represent the depositional imprint of the last high-magnitude lake outburst. The subglacial lakes and channels are preserved on top of glacial lineations, indicating long-term re-organization of the subglacial drainage system and coupling to ice flow. PMID:27292049

Outburst floods from glacier-dammed lakes: The effect of mode of lake drainage on flood magnitude

USGS Publications Warehouse

Walder, J.S.; Costa, J.E.

1996-01-01

Published accounts of outburst floods from glacier-dammed lakes show that a significant number of such floods are associated not with drainage through a tunnel incised into the basal ice - the process generally assumed - but rather with ice-marginal drainage, mechanical failure of part of the ice dam, or both. Non-tunnel floods are strongly correlated with formation of an ice dam by a glacier advancing from a tributary drainage into either a main river valley or a pre-existing body of water (lake or fiord). For a given lake volume, non-tunnel floods tend to have significantly higher peak discharges than tunnel-drainage floods. Statistical analysis of data for floods associated with subglacial tunnels yields the following empirical relation between lake volume V and peak discharge script Q signp : script Q signp = 46V0.66 (r2 = 0.70), when script Q signp is expressed in metres per second and V in millions of cubic metres. This updates the so-called Clague-Mathews relation. For non-tunnel floods, the analogous relation is script Q signp = 1100V0.44 (r2 = 0.58). The latter relation is close to one found by Costa (1988) for failure of constructed earthen dams. This closeness is probably not coincidental but rather reflects similarities in modes of dam failure and lake drainage. We develop a simple physical model of the breach-widening process for non-tunnel floods, assuming that (1) the rate of breach widening is controlled by melting of the ice, (2) outflow from the lake is regulated by the hydraulic condition of critical flow where water enters the breach, and (3) the effect of lake temperature may be dealt with as done by Clarke (1982). Calculations based on the model simulate quite well outbursts from Lake George, Alaska. Dimensional analysis leads to two approximations of the form script Q signp ??? Vqf(hi, ??0), where q = 0.5 to 0.6, hi is initial lake depth, ??0 is lake temperature, and the form of f(hi, ??0) depends on the relative importance of viscous

Potential subglacial lake locations and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets

NASA Astrophysics Data System (ADS)

Livingstone, S. J.; Clark, C. D.; Woodward, J.; Kingslake, J.

2013-11-01

We use the Shreve hydraulic potential equation as a simplified approach to investigate potential subglacial lake locations and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets. We validate the method by demonstrating its ability to recall the locations of >60% of the known subglacial lakes beneath the Antarctic Ice Sheet. This is despite uncertainty in the ice-sheet bed elevation and our simplified modelling approach. However, we predict many more lakes than are observed. Hence we suggest that thousands of subglacial lakes remain to be found. Applying our technique to the Greenland Ice Sheet, where very few subglacial lakes have so far been observed, recalls 1607 potential lake locations, covering 1.2% of the bed. Our results will therefore provide suitable targets for geophysical surveys aimed at identifying lakes beneath Greenland. We also apply the technique to modelled past ice-sheet configurations and find that during deglaciation both ice sheets likely had more subglacial lakes at their beds. These lakes, inherited from past ice-sheet configurations, would not form under current surface conditions, but are able to persist, suggesting a retreating ice-sheet will have many more subglacial lakes than advancing ones. We also investigate subglacial drainage pathways of the present-day and former Greenland and Antarctic ice sheets. Key sectors of the ice sheets, such as the Siple Coast (Antarctica) and NE Greenland Ice Stream system, are suggested to have been susceptible to subglacial drainage switching. We discuss how our results impact our understanding of meltwater drainage, basal lubrication and ice-stream formation.

Early Holocene estuary development of the Hesselø Bay area, southern Kattegat, Denmark and its implication for Ancylus Lake drainage

NASA Astrophysics Data System (ADS)

Bendixen, Carina; Boldreel, Lars Ole; Jensen, Jørn Bo; Bennike, Ole; Hübscher, Christian; Clausen, Ole Rønø

2017-12-01

High-resolution shallow seismic data, sediment core information, radiocarbon dating and sequence stratigraphy have been used to interpret the late glacial to early Holocene geological evolution of Hesselø Bay in the southern Kattegat, Denmark. A reconstruction of the early Holocene coastal environment and a description of coastal processes associated with a river outlet into the bay are presented. Weichselian glacial deposits form the lowermost interpreted unit, covered by late glacial (LG) and postglacial (PG, Holocene) sediments. A funnel-shaped estuary existed at the mouth of channels in the period 10.3-9.2 cal. ka BP; the channels drained water from south to north. The early PG is characterised by estuarine and coastal deposits. The early Holocene bars that developed in the estuary are preserved as morphological features on the present-day seabed, possibly as a result of rapid relative sea-level rise. The estuary existed simultaneously with the occurrence and drainage of the Ancylus Lake. The drainage of this lake occurred through the Dana River (palaeo-Great Belt channel) into the southern Kattegat and then into the study area. The level of the Ancylus Lake in the Baltic Sea region dropped significantly at about 10.2 cal. ka BP at the same time as the estuary developed in the Kattegat region. One outcome of the present study is an enhanced understanding of the Ancylus Lake drainage path. No evidence of major erosion is seen, which indicates non-catastrophic continuous water flow from the south without major drainage events of the Ancylus Lake to the southern Kattegat. During the Littorina transgression, coastal estuarine conditions characterized the Hesselø Bay area where elongated ridges formed a bar system. As the Littorina transgression continued, back-stepping of the bar system and coastline occurred. When the transgression breached the Great Belt threshold, flooding caused major erosion throughout the study area.

Lasting Effects of Glacial Lake Outburst Floods on Subglacial Drainage Networks

NASA Astrophysics Data System (ADS)

Robbins, M.; Hendy, I. L.; Bassis, J. N.; Aciego, S.; Stevenson, E. I.

2017-12-01

Supraglacial lakes forming in the ablation zone around the Greenland Ice Sheet will likely migrate toward higher elevations as polar temperatures rise through the 21st century. Present understanding of lake drainage shows it can temporarily enhance ice sheet motion, but other possible effects and interactions - especially with older pre-existing subglacial reservoirs - remain unexamined. Here we investigate possible enduring effects of the record high 2012 melt year on the en/subglacial hydrologic network, how this network responds to immediate high fluxes of water from floods, and how these phenomena might connect to previously isolated subglacial pools. Lake Hullet is a large ice dammed lake situated in south Greenland 22km up-ice from where Kiattuut Sermiat (KS) branches from a larger outlet glacier. Lake Hullet rests on bedrock and is contained by a bedrock ridge. It drains roughly annually through Lake Hullet's hydrologic network in a glacial lake outburst flood (GLOF) when water level rises such that it can flow over the obstructive ridge. Subglacial water samples collected from the toe of KS in July 2013 pre-flood were dated using U isotopes with 222Rn concentrations as well as noble gas ratios. These two independent methods reveal an exceedingly old water age of > 1000 years, indicating existence of isolated enduring subglacial meltwater pool(s). A comparison field study at the KS toe in August and September 2015 re-examined glacial hydrochemistry in a time series. 2015 222Rn concentrations are lower than 2013 values, suggesting less water-rock interaction, a reduction in residence time, and a proximal meltwater source. Increased water volume from the record high 2012 melt year may have enlarged the existing en/subglacial drainage network further into the ice sheet releasing meltwater with longer residence times beneath the ice, with effects lasting into subsequent melt seasons due to the stability of channels maintained from recurrent floods. These

Population structure of sea-type and lake-type sockeye salmon and kokanee in the Fraser River and Columbia River drainages

PubMed Central

Withler, Ruth E.

2017-01-01

Population structure of three ecotypes of Oncorhynchus nerka (sea-type Sockeye Salmon, lake-type Sockeye Salmon, and Kokanee) in the Fraser River and Columbia River drainages was examined with microsatellite variation, with the main focus as to whether Kokanee population structure within the Fraser River drainage suggested either a monophyletic or polyphyletic origin of the ecotype within the drainage. Variation at 14 microsatellite loci was surveyed for sea-type and lake-type Sockeye Salmon and Kokanee sampled from 121 populations in the two river drainages. An index of genetic differentiation, FST, over all populations and loci was 0.087, with individual locus values ranging from 0.031 to 0.172. Standardized to an ecotype sample size of 275 individuals, the least genetically diverse ecotype was sea-type Sockeye Salmon with 203 alleles, whereas Kokanee displayed the greatest number of alleles (260 alleles), with lake-type Sockeye Salmon intermediate (241 alleles). Kokanee populations from the Columbia River drainage (Okanagan Lake, Kootenay Lake), the South Thompson River (a major Fraser River tributary) drainage populations, and the mid-Fraser River populations all clustered together in a neighbor-joining analysis, indicative of a monophyletic origin of the Kokanee ecotype in these regions, likely reflecting the origin of salmon radiating from a refuge after the last glaciation period. However, upstream of the mid-Fraser River populations, there were closer relationships between the lake-type Sockeye Salmon ecotype and the Kokanee ecotype, indicative of the Kokanee ecotype evolving independently from the lake-type Sockeye Salmon ecotype in parallel radiation. Kokanee population structure within the entire Fraser River drainage suggested a polyphyletic origin of the ecotype within the drainage. Studies employing geographically restricted population sampling may not outline accurately the phylogenetic history of salmonid ecotypes. PMID:28886033

Destruction of the ecosystem in the Great Lakes and possibilities for its reconstruction

USGS Publications Warehouse

Smith, Stanford H.; Moore, Remedios W.

1972-01-01

This paper is a review of the sequence of events within the Great Lakes and their drainage to provide a basis for interpreting probable cause-and-effect relations between events of settlement and changes in the ecosystem of the Great Lakes. Possibilities of restoration of the lakes are discussed. A plan to do so must include (1) improvement of land uses in the drainage basin, (2) elimination of sources of physical, chemical, and biological pollution entering the lakes, and (3) restoration of favorable and productive fish populations.

Drainage network structure and hydrologic behavior of three lake-rich watersheds on the Arctic Coastal Plain, Alaska

USGS Publications Warehouse

Arp, C.D.; Whitman, M.S.; Jones, Benjamin M.; Kemnitz, R.; Grosse, G.; Urban, F.E.

2012-01-01

Watersheds draining the Arctic Coastal Plain (ACP) of Alaska are dominated by permafrost and snowmelt runoff that create abundant surface storage in the form of lakes, wetlands, and beaded streams. These surface water elements compose complex drainage networks that affect aquatic ecosystem connectivity and hydrologic behavior. The 4676 km2 Fish Creek drainage basin is composed of three watersheds that represent a gradient of the ACP landscape with varying extents of eolian, lacustrine, and fluvial landforms. In each watershed, we analyzed 2.5-m-resolution aerial photography, a 5-m digital elevation model, and river gauging and climate records to better understand ACP watershed structure and processes. We show that connected lakes accounted for 19 to 26% of drainage density among watersheds and most all channels initiate from lake basins in the form of beaded streams. Of the > 2500 lakes in these watersheds, 33% have perennial streamflow connectivity, and these represent 66% of total lake area extent. Deeper lakes with over-wintering habitat were more abundant in the watershed with eolian sand deposits, while the watershed with marine silt deposits contained a greater extent of beaded streams and shallow thermokarst lakes that provide essential summer feeding habitat. Comparison of flow regimes among watersheds showed that higher lake extent and lower drained lake-basin extent corresponded with lower snowmelt and higher baseflow runoff. Variation in baseflow runoff among watersheds was most pronounced during drought conditions in 2007 with corresponding reduction in snowmelt peak flows the following year. Comparison with other Arctic watersheds indicates that lake area extent corresponds to slower recession of both snowmelt and baseflow runoff. These analyses help refine our understanding of how Arctic watersheds are structured and function hydrologically, emphasizing the important role of lake basins and suggesting how future lake change may impact hydrologic

The 2005 catastrophic acid crater lake drainage, lahar, and acidic aerosol formation at Mount Chiginagak volcano, Alaska, USA: Field observations and preliminary water and vegetation chemistry results

NASA Astrophysics Data System (ADS)

Schaefer, Janet R.; Scott, William E.; Evans, William C.; Jorgenson, Janet; McGimsey, Robert G.; Wang, Bronwen

2008-07-01

A mass of snow and ice 400-m-wide and 105-m-thick began melting in the summit crater of Mount Chiginagak volcano sometime between November 2004 and early May 2005, presumably owing to increased heat flux from the hydrothermal system, or possibly from magma intrusion and degassing. In early May 2005, an estimated 3.8 × 106 m3 of sulfurous, clay-rich debris and acidic water, with an accompanying acidic aerosol component, exited the crater through a tunnel at the base of a glacier that breaches the south crater rim. Over 27 km downstream, the acidic waters of the flood inundated an important salmon spawning drainage, acidifying Mother Goose Lake from surface to depth (approximately 0.5 km3 in volume at a pH of 2.9 to 3.1), killing all aquatic life, and preventing the annual salmon run. Over 2 months later, crater lake water sampled 8 km downstream of the outlet after considerable dilution from glacial meltwater was a weak sulfuric acid solution (pH = 3.2, SO4 = 504 mg/L, Cl = 53.6 mg/L, and F = 7.92 mg/L). The acid flood waters caused severe vegetation damage, including plant death and leaf kill along the flood path. The crater lake drainage was accompanied by an ambioructic flow of acidic aerosols that followed the flood path, contributing to defoliation and necrotic leaf damage to vegetation in a 29 km2 area along and above affected streams, in areas to heights of over 150 m above stream level. Moss species killed in the event contained high levels of sulfur, indicating extremely elevated atmospheric sulfur content. The most abundant airborne phytotoxic constituent was likely sulfuric acid aerosols that were generated during the catastrophic partial crater lake drainage event. Two mechanisms of acidic aerosol formation are proposed: (1) generation of aerosol mist through turbulent flow of acidic water and (2) catastrophic gas exsolution. This previously undocumented phenomenon of simultaneous vegetation-damaging acidic aerosols accompanying drainage of an acidic

The 2005 catastrophic acid crater lake drainage, lahar, and acidic aerosol formation at Mount Chiginagak volcano, Alaska, USA: Field observations and preliminary water and vegetation chemistry results

USGS Publications Warehouse

Schaefer, J.R.; Scott, W.E.; Evans, William C.; Jorgenson, J.; McGimsey, R.G.; Wang, B.

2008-01-01

A mass of snow and ice 400-m-wide and 105-m-thick began melting in the summit crater of Mount Chiginagak volcano sometime between November 2004 and early May 2005, presumably owing to increased heat flux from the hydrothermal system, or possibly from magma intrusion and degassing. In early May 2005, an estimated 3.8??106 m3 of sulfurous, clay-rich debris and acidic water, with an accompanying acidic aerosol component, exited the crater through a tunnel at the base of a glacier that breaches the south crater rim. Over 27 km downstream, the acidic waters of the flood inundated an important salmon spawning drainage, acidifying Mother Goose Lake from surface to depth (approximately 0.5 km3 in volume at a pH of 2.9 to 3.1), killing all aquatic life, and preventing the annual salmon run. Over 2 months later, crater lake water sampled 8 km downstream of the outlet after considerable dilution from glacial meltwater was a weak sulfuric acid solution (pH = 3.2, SO4 = 504 mg/L, Cl = 53.6 mg/L, and F = 7.92 mg/L). The acid flood waters caused severe vegetation damage, including plant death and leaf kill along the flood path. The crater lake drainage was accompanied by an ambioructic flow of acidic aerosols that followed the flood path, contributing to defoliation and necrotic leaf damage to vegetation in a 29 km2 area along and above affected streams, in areas to heights of over 150 m above stream level. Moss species killed in the event contained high levels of sulfur, indicating extremely elevated atmospheric sulfurcontent. The most abundant airborne phytotoxic constituent was likely sulfuric acid aerosols that were generated during the catastrophic partial crater lake drainage event. Two mechanisms of acidic aerosol formation are proposed: (1) generation of aerosol mist through turbulent flow of acidic water and (2) catastrophic gas exsolution. This previously undocumented phenomenon of simultaneous vegetationdamaging acidic aerosols accompanying drainage of an acidic crater

The drainage of the Baltic Ice Lake and a new Scandinavian reference 10Be production rate

NASA Astrophysics Data System (ADS)

Stroeven, Arjen P.; Heyman, Jakob; Fabel, Derek; Björck, Svante; Caffee, Marc W.; Fredin, Ola; Harbor, Jonathan M.

2015-04-01

An important constraint on the reliability of cosmogenic nuclide exposure dating is the derivation of tightly controlled production rates. We present a new dataset for 10Be production rate calibration from Mount Billingen, southern Sweden, the site of the final drainage of the Baltic Ice Lake, an event dated to 11,620 ± 100 cal yr BP. Nine samples of flood-scoured bedrock surfaces and depositional boulders and cobbles unambiguously connected to the drainage event yield a reference 10Be production rate of 4.09 ± 0.22 atoms g-1 yr-1 for the CRONUS Lm scaling and 3.93 ± 0.21 atoms g-1 yr-1 for the LSD general spallation scaling. We also recalibrate the reference 10Be production rates for four sites in Norway and combine these with the Billingen results to derive a tightly clustered Scandinavian reference 10Be production rate of 4.12 ± 0.10 (4.12 ± 0.25 for altitude scaling) atoms g-1 yr-1 for the Lm scaling scheme and 3.96 ± 0.10 (3.96 ± 0.24 for altitude scaling) atoms g-1 yr-1 for the LSD scaling scheme.

Fluvial sediment study of Fishtrap and Dewey Lakes drainage basins, Kentucky - Virginia

USGS Publications Warehouse

Curtis, William F.; Flint, Russell F.; George, Frederick H.; Santos, John F.

1978-01-01

Fourteen drainage basins above Fishtrap and Dewey Lakes in the Levisa Fork and Johns Creek drainage basins of eastern Kentucky and southwestern Virginia were studied to determine sedimentation rates and origin of sediment entering the two lakes. The basins ranged in size from 1.68 to 297 square miles. Sediment yields ranged from 2,890 to 21,000 tons per square mile where surface-mining techniques predominated, and from 732 to 3 ,470 tons per square mile where underground mining methods predominated. Yields, in terms of tons per acre-foot of runoff, ranged from 2.2 to 15 for surface-mined areas, and from 0.5 to 2.7 for underground-mined areas. Water and sediment discharges from direct runoff during storms were compared for selected surface-mined and underground-mined areas. Data points of two extensively surface-mined areas, one from the current project and one from a previous project in Beaver Creek basin, McCreary County, Kentucky, grouped similarly in magnitude and by season. Disturbed areas from mining activities determined from aerial photographs reached 17 percent in one study area where extensive surface mining was being practiced. For most areas where underground mining was practiced, percentage disturbed area was almost negligible. Trap efficiency of Fishtrap Lake was 89 percent, and was 62 percent for Dewey Lake. Average annual deposition rates were 464 and 146 acre-feet for Fishtrap and Dewey Lakes, respectively. The chemical quality of water in the Levisa Fork basin has been altered by man 's activities. (Woodard-USGS)

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

Hydrogeologic Controls on Lake Level at Mountain Lake, Virginia

NASA Astrophysics Data System (ADS)

Roningen, J. M.; Burbey, T. J.

2011-12-01

Mountain Lake in Giles County, Virginia has a documented history of severe natural lake-level changes involving groundwater seepage that extend over the past 4200 years. Featured in the 1986 movie Dirty Dancing, the natural lake dried up completely in September 2008 and levels have not yet recovered. A hydrogeologic investigation was undertaken in an effort to determine the factors influencing lake level changes. A daily water balance, dipole-dipole electrical resistivity surveying, well logging and chemical sampling have shed light on: 1) the influence of a fault not previously discussed in literature regarding the lake, 2) the seasonal response to precipitation of a forested first-order drainage system in fractured rock, and 3) the possibility of flow pathways related to karst features. Geologic controls on lake level were investigated using several techniques. Geophysical surveys using dipole-dipole resistivity located possible subsurface flowpaths both to and from the lake. Well logs, lineament analysis, and joint sampling were used to assess structural controls on lake hydrology. Major ions were sampled at wells, springs, streams, and the lake to evaluate possible mixing of different sources of water in the lake. Groundwater levels were monitored for correlation to lake levels, rainfall events, and possible seismic effects. The hydrology of the lake was quantified with a water balance on a daily time step. Results from the water balance indicate steady net drainage and significant recharge when vegetation is dormant, particularly during rain-on-snow melt events. The resistivity survey reveals discrete areas that represent flow pathways from the lake, as well as flowpaths to springs upgradient of the lake located in the vicinity of the fault. The survey also suggests that some flowpaths may originate outside of the topographic watershed of the lake. Chemical evidence indicates karst may underlie the lakebed. Historical data suggest that artificial intervention

Links Between Acceleration, Melting, and Supraglacial Lake Drainage of the Western Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Hoffman, M. J.; Catania, G. A.; Newmann, T. A.; Andrews, L. C.; Rumrill, J. A.

2012-01-01

The impact of increasing summer melt on the dynamics and stability of the Greenland Ice Sheet is not fully understood. Mounting evidence suggests seasonal evolution of subglacial drainage mitigates or counteracts the ability of surface runoff to increase basal sliding. Here, we compare subdaily ice velocity and uplift derived from nine Global Positioning System stations in the upper ablation zone in west Greenland to surface melt and supraglacial lake drainage during summer 2007. Starting around day 173, we observe speedups of 6-41% above spring velocity lasting approximately 40 days accompanied by sustained surface uplift at most stations, followed by a late summer slowdown. After initial speedup, we see a spatially uniform velocity response across the ablation zone and strong diurnal velocity variations during periods of melting. Most lake drainages were undetectable in the velocity record, and those that were detected only perturbed velocities for approximately 1 day, suggesting preexisting drainage systems could efficiently drain large volumes of water. The dynamic response to melt forcing appears to 1) be driven by changes in subglacial storage of water that is delivered in diurnal and episodic pulses, and 2) decrease over the course of the summer, presumably as the subglacial drainage system evolves to greater efficiency. The relationship between hydrology and ice dynamics observed is similar to that observed on mountain glaciers, suggesting that seasonally large water pressures under the ice sheet largely compensate for the greater ice thickness considered here. Thus, increases in summer melting may not guarantee faster seasonal ice flow.

Links Between Acceleration, Melting, and Supraglacial Lake Drainage of the Western Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Hoffman, M. J.; Catania, G. A.; Neumann, T. A.; Andrews, L. C.; Rumrill, J. A.

2011-01-01

The impact of increasing summer melt on the dynamics and stability of the Greenland Ice Sheet is not fully understood. Mounting evidence suggests seasonal evolution of subglacial drainage mitigates or counteracts the ability of surface runoff to increase basal sliding. Here, we compare subdaily ice velocity and uplift derived from nine Global Positioning System stations in the upper ablation zone in west Greenland to surface melt and supraglacial lake drainage during summer 2007. Starting around day 173, we observe speedups of 6-41% above spring velocity lasting 40 days accompanied by sustained surface uplift at most stations, followed by a late summer slowdown. After initial speedup, we see a spatially uniform velocity response across the ablation zone and strong diurnal velocity variations during periods of melting. Most lake drainages were undetectable in the velocity record, and those that were detected only perturbed velocities for approx 1 day, suggesting preexisting drainage systems could efficiently drain large volumes of water. The dynamic response to melt forcing appears to (1) be driven by changes in subglacial storage of water that is delivered in diurnal and episodic pulses, and (2) decrease over the course of the summer, presumably as the subglacial drainage system evolves to greater efficiency. The relationship between hydrology and ice dynamics observed is similar to that observed on mountain glaciers, suggesting that seasonally large water pressures under the ice sheet largely compensate for the greater ice thickness considered here. Thus, increases in summer melting may not guarantee faster seasonal ice flow.

Annual glacier dammed lake drainage in Zackenberg, Northeast Greenland

NASA Astrophysics Data System (ADS)

Lane, Timothy; Adamson, Kathryn; Matthews, Tom

2016-04-01

A.P. Olsen is a 295 km2 ice cap in the Zackenberg region of Northeast Greenland (74.6° N, 21.5° W), 35 km from the ZERO Zackenberg Research Station. The ice cap lies on a gneissic plateau, covering an elevation of 200 to 1450 m a.s.l. A.P. Olsen mass balance has been monitored since 2008 and reconstructed for the period 1995-2007. Meltwater from this ice cap drains into the Zackenberg River, and into Young Sund via the Zackenberg Delta. One outlet dams a c. 0.8 km2 lake fed by the northern part of the ice cap. Observational data suggests this lake drains annually, flooding subglacially into the Zackenberg River. But the impacts of these flood events on the hydrology, sediment transfer, and geomorphology of the proglacial zone downstream have not been examined in detail. Understanding the impacts of glacial lake outburst flood events is important in the sensitive Arctic environment, where glacial change is rapid. We use Landsat scenes to reconstruct lake extent from 1999-2015. This is compared to Zackenberg River discharge measurements, available from the ZERO Zackenberg monitoring programme. These datasets are used to examine the nature and timing of flood events, and assess the impacts on the Zackenberg river downstream.

Large drainages from short-lived glacial lakes in the Teskey Range, Tien Shan Mountains, Central Asia

NASA Astrophysics Data System (ADS)

Narama, Chiyuki; Daiyrov, Mirlan; Duishonakunov, Murataly; Tadono, Takeo; Sato, Hayato; Kääb, Andreas; Ukita, Jinro; Abdrakhmatov, Kanatbek

2018-04-01

Four large drainages from glacial lakes occurred during 2006-2014 in the western Teskey Range, Kyrgyzstan. These floods caused extensive damage, killing people and livestock as well as destroying property and crops. Using satellite data analysis and field surveys of this area, we find that the water volume that drained at Kashkasuu glacial lake in 2006 was 194 000 m3, at western Zyndan lake in 2008 was 437 000 m3, at Jeruy lake in 2013 was 182 000 m3, and at Karateke lake in 2014 was 123 000 m3. Due to their subsurface outlet, we refer to these short-lived glacial lakes as the tunnel-type, a type that drastically grows and drains over a few months. From spring to early summer, these lakes either appear, or in some cases, significantly expand from an existing lake (but non-stationary), and then drain during summer. Our field surveys show that the short-lived lakes form when an ice tunnel through a debris landform gets blocked. The blocking is caused either by the freezing of stored water inside the tunnel during winter or by the collapse of ice and debris around the ice tunnel. The draining then occurs through an opened ice tunnel during summer. The growth-drain cycle can repeat when the ice-tunnel closure behaves like that of typical supraglacial lakes on debris-covered glaciers. We argue here that the geomorphological characteristics under which such short-lived glacial lakes appear are (i) a debris landform containing ice (ice-cored moraine complex), (ii) a depression with water supply on a debris landform as a potential lake basin, and (iii) no visible surface outflow channel from the depression, indicating the existence of an ice tunnel. Applying these characteristics, we examine 60 depressions (> 0.01 km2) in the study region and identify here 53 of them that may become short-lived glacial lakes, with 34 of these having a potential drainage exceeding 10 m3 s-1 at peak discharge.

Deglaciation of the James Bay Lowlands and Northern Abitibi: Insights on Late-Glacial Ice Readvances and Drainage of Glacial Lake Ojibway

NASA Astrophysics Data System (ADS)

Roy, M.; Veillette, J. J.; Dell'Oste, F.

2008-12-01

Deglaciation in the James Bay region was marked by the scission of the Laurentide ice sheet margin into the Hudson dome to the west and the New-Quebec dome to the east, which subsequently retreated northward, in contact with the waters of glacial Lake Ojibway. Previous work based on air photo-interpretation and field observations indicate that ice retreat in the region was highly dynamic, with the occurrence of at least three ice readvances into the basin of Lake Objiway prior to the final deglaciation, and the incursion of the post- glacial Tyrrell Sea at ~8 ka (Hardy, 1976). Our investigations of stratigraphic sections exposed along the Harricana, Nottaway, Broadback, and Rupert rivers in the lowlands of Quebec indicate that only part of these events are preserved in these sedimentary sequences. The base of the late-glacial sequence generally consists of a carbonate-bearing clayey readvance till that lies on older tills of the last glacial cycle, or truncate Lake Ojibway glaciolacustrine sediments. None of the sections showed more than one till of the three (Cochrane I, Rupert, Cochrane II) readvances documented in the region. Nonetheless, an extensive Ojibway sequence located just south from the lowlands shows three intervals with significant increases in detrital carbonate and coarsening of the varve sequence that can be linked with these late-glacial surges. In the lowlands, the readvance till is commonly capped by a thick sequence of Ojibway varves. The contact between the glaciolacustrine sediments and the overlying Tyrrell Sea marine deposits is marked by a ~50 cm-thick horizon composed at the bottom of thinly laminated reddish and grey silt beds containing abundant rounded clay balls, overlain by coarser silts and fine sands with disseminated clasts. This horizon is here interpreted to reflect the abrupt drainage of Lake Ojibway. Recent radiocarbon dating of mollusks and foraminifers from the uppermost part of this horizon yielded ages of ~7.7 ka and ~8

Capturing Flow-weighted Water and Suspended Particulates from Agricultural Canals During Drainage Events.

PubMed

Bhadha, Jehangir H; Sexton, Anne; Lang, Timothy A; Daroub, Samira H

2017-11-07

The purpose of this study is to describe the methods used to capture flow-weighted water and suspended particulates from farm canals during drainage discharge events. Farm canals can be enriched by nutrients such as phosphorus (P) that are susceptible to transport. Phosphorus in the form of suspended particulates can significantly contribute to the overall P loads in drainage water. A settling tank experiment was conducted to capture suspended particulates during discrete drainage events. Farm canal discharge water was collected in a series of two 200 L settling tanks over the entire duration of the drainage event, so as to represent a composite subsample of the water being discharged. Imhoff settling cones are ultimately used to settle out the suspended particulates. This is achieved by siphoning water from the settling tanks via the cones. The particulates are then collected for physico-chemical analyses.

Tracking surface and subsurface lakes on the Greenland Ice Sheet using Sentinel-1 SAR and Landsat-8 OLI imagery

NASA Astrophysics Data System (ADS)

Miles, Katie; Willis, Ian; Benedek, Corinne; Williamson, Andrew; Tedesco, Marco

2017-04-01

Supraglacial lakes (SGLs) on the Greenland Ice Sheet (GrIS) are an important component of the ice sheet's mass balance and hydrology, with their drainage affecting ice dynamics. This study uses imagery from the recently launched Sentinel-1A Synthetic Aperture Radar (SAR) to investigate SGLs in West Greenland. SAR can image through cloud and in darkness, overcoming some of the limitations of commonly used optical sensors. A semi automated algorithm is developed to detect surface lakes from Sentinel images during the 2015 summer. It generally detects water in all locations where a Landsat-8 NDWI classification (with a relatively high threshold value) detects water. A combined set of images from Landsat-8 and Sentinel-1 is used to track lake behaviour at a comparable temporal resolution to that which is possible with MODIS, but at a higher spatial resolution. A fully automated lake drainage detection algorithm is used to investigate both rapid and slow drainages for both small and large lakes through the summer. Our combined Landsat-Sentinel dataset, with a temporal resolution of three days, could track smaller lakes (mean 0.089 km2) than are resolvable in MODIS (minimum 0.125 km2). Small lake drainage events (lakes smaller than can be detected using MODIS) were found to occur at lower elevations ( 200 m) and slightly earlier in the melt season than larger events, as were slow lake drainage events compared to rapid events. The Sentinel imagery allows the analysis to be extended manually into the early winter to calculate the dates and elevations of lake freeze-through more precisely than is possible with optical imagery (mean 30 August, 1270 m mean elevation). Finally, the Sentinel imagery allows subsurface lakes (which are invisible to optical sensors) to be detected, and, for the first time, their dates of appearance and freeze-through to be calculated (mean 9 August and 7 October, respectively). These subsurface lakes occur at higher elevations than the surface

Controls of event-based nutrient transport within nested headwater agricultural watersheds of the western Lake Erie basin

NASA Astrophysics Data System (ADS)

Williams, Mark R.; Livingston, Stanley J.; Penn, Chad J.; Smith, Douglas R.; King, Kevin W.; Huang, Chi-hua

2018-04-01

Understanding the processes controlling nutrient delivery in headwater agricultural watersheds is essential for predicting and mitigating eutrophication and harmful algal blooms in receiving surface waters. The objective of this study was to elucidate nutrient transport pathways and examine key components driving nutrient delivery processes during storm events in four nested agricultural watersheds (298-19,341 ha) in the western Lake Erie basin with poorly drained soils and an extensive artificial drainage network typical of the Midwestern U.S. Concentration-discharge hysteresis patterns of nitrate-nitrogen (NO3-N), dissolved reactive phosphorus (DRP), and particulate phosphorus (PP) occurring during 47 storm events over a 6 year period (2004-2009) were evaluated. An assessment of the factors producing nutrient hysteresis was completed following a factor analysis on a suite of measured environmental variables representing the fluvial and wider watershed conditions prior to, and during the monitored storm events. Results showed the artificial drainage network (i.e., surface tile inlets and subsurface tile drains) in these watersheds was the primary flow pathway for nutrient delivery to streams, but nutrient behavior and export during storm events was regulated by the flow paths to and the intensity of the drainage network, the availability of nutrients, and the relative contributions of upland and in-stream nutrient sources. Potential sources and flow pathways for transport varied among NO3-N, PP, and DRP with results underscoring the challenge of mitigating nutrient loss in these watersheds. Conservation practices addressing both nutrient management and hydrologic connectivity will likely be required to decrease nutrient loss in artificially drained landscapes.

Extent and drainage status of organic soils in the Lake Victoria catchment

NASA Astrophysics Data System (ADS)

Barthelmes, Reni; Barthelmes, Alexandra; Joosten, Hans

2016-04-01

When considering peatlands and organic soils in the tropics, the huge areas in SE Asia prevail in public and scientific perception, whereas Africa has largely been out of focus. However, East Africa contains large areas of organic soils as well. They basically occur in the high altitudes of the uplifted flanks of the East African Rift System, isolated volcanoes and the Ethiopian highlands, in the Zambezian floodplains (e.g. Zambia), and in coastal environments (e.g. Mozambique and Madagascar). We used a mapping approach that integrates old field data and maps, specialized landscape and peatland-related knowledge, and modern RS and GIS techniques to elaborate a comprehensive and rather reliable overview of organic soils (incl. peatlands) in the Lake Victoria catchment. Maps at a scale of 1:25,000 have been prepared for Burundi, Kenya, Rwanda, Tanzania and Uganda. The land use intensity has been estimated for all organic soil areas based on satellite and aerial imagery. Feeding the Nile River, sustaining a fast growing and widely poor population and already facing climatic changes, organic soils of the Lake Victoria neighbouring countries are partially under heavy threat. We mapped 10,645 km2 of organic soils for the entire area of which 8,860 km2 (83.2%) seem to be in near natural condition. We assume slightly drainage and low degradation for 564 km2 (5.3%) and intensive drainage and heavy degradation for 1,222 km2 (11.5%). Degradation hotspot is Burundi with 522 km2 (79.5%) of heavily drained and degrading organic soils. This area assessment has been quite conservative to not overestimate the extent of organic soils. A reserve of 5-7,000 km2 of wetlands in the Lake Victoria catchment may include peatlands too, which needs to be confirmed in field surveys. Considering the key role of peatlands and organic soils for water provision and regulation and their rapid degradation due to drainage and inappropriate use, this inventory might be a step towards organic soil

Connecting Indigenous Knowledge to Thaw Lake Cycle Research on the Arctic Coastal Plain of Alaska

NASA Astrophysics Data System (ADS)

Eisner, W. R.; Cuomo, C. J.; Hinkel, K. M.; Jones, B. M.; Hurd, J.

2005-12-01

pinpointed the year of drainage where we previously had only bracketed a 5-10 year period in which drainage must have occurred. Our informants were also often able to identify the cause of the drainage event, the process by which it occurred, and the aftermath of the event (i.e. overflow into other lakes, changes in stream hydrology, changes in fish species, etc.). We have also noted a difference in the reports of lake drainage and other landscape changes between the people who have more knowledge of the Inner (Atqasuk residents) and Outer (Barrow residents) Coastal Plain. Travelers of the Outer Coastal Plain have identified more lake drainage events. The people of the Inner Coastal Plain, conversely, speak of lower water levels in lakes and overall drier conditions in recent years. The quantity of information from the Barrow and Atqasuk elders and the precision of their observations is impressive. We will be analyzing, by both quantitative and qualitative methods, this information in conjunction with our ongoing studies of thaw-lake processes on the Arctic Coastal Plain. In addition to discussing specific knowledge about thaw-lake processes, we are archiving the range of knowledge and stories that elders, hunters, and other users of the tundra introduce to the interviews. We believe the traditional knowledge and ongoing observations of the Iñupiat are highly valuable to scientists and society in general, and we strongly advocate further cooperation between traditional and scientific "ways of knowing."

A climatology of weather-driven mixing events in a dimictic Arctic lake

NASA Astrophysics Data System (ADS)

Cooke, Melanie; MacIntyre, Sally; Kushner, Paul

2014-05-01

For dimictic and polymictic Arctic lakes, mixing during the ice-free season is primarily controlled by the passage of cold fronts and their associated strong winds. At Toolik Lake, a Long Term Ecological Research site in Alaska, year-to-year variability in lake stability and mixing frequency has been considerable over the past 14 summers. Mixing is important for lake productivity, distributing dissolved gases and nutrients through the water column. Summertime Arctic warming might be expected to stabilize Arctic lakes such as Toolik, but the control of individual weather events on a season's mixing characteristics complicates the ability to predict trends in stability and mixing. With this motivation, this work aims to characterize weather systems that are conducive to mixing at Toolik. High resolution lake and meteorological data from the site were used to characterize mixing while atmospheric reanalysis data were used to describe the weather systems. Mixing events were first identified using an automated algorithm based on Lake Number and lake thermal structure. The algorithm identified mixing events that are separated by at least the timescale of weather systems, so that any given weather event should cause at most one mixing event. Because low Lake Number conditions typically highlight strong wind events, temperature profile data over time were used to identify thermocline deepening as a complementary indicator for mixing. Mixing events were found to be most often characterized by simultaneous occurrence of a low Lake Number condition and thermocline deepening. Once mixing events were identified, they were classified according to their corresponding atmospheric structures. Two primary weather system types with distinct characteristics were determined to be associated with mixing. The analysis suggests that changing the occurrence of these weather system types might change the summertime thermal structure of Toolik Lake, and by extension other lakes in the region.

Linking the 8.2 ka Event and its Freshwater Forcing in the Labrador Sea

NASA Technical Reports Server (NTRS)

Hoffman, Jeremy S.; Carlson, Anders E.; Winsor, Kelsey; Klinkhammer, Gary P.; LeGrande, Allegra N.; Andrews, John T.; Strasser, C.

2012-01-01

The 8.2 ka event was the last deglacial abrupt climate event. A reduction in the Atlantic meridional overturning circulation (AMOC) attributed to the drainage of glacial Lake Agassiz may have caused the event, but the freshwater signature of Lake Agassiz discharge has yet to be identified in (delta)18O of foraminiferal calcite records from the Labrador Sea, calling into question the connection between freshwater discharge to the North Atlantic and AMOC strength. Using Mg/Ca-paleothermometry, we demonstrate that approx. 3 C of near-surface ocean cooling masked an 1.0 % decrease in western Labrador Sea (delta)18O of seawater concurrent with Lake Agassiz drainage. Comparison with North Atlantic (delta)18O of seawater records shows that the freshwater discharge was transported to regions of deep-water formation where it could perturb AMOC and force the 8.2 ka event.

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.

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)

Environmental conditions synchronize waterbird mortality events in the Great Lakes

USGS Publications Warehouse

Prince, Karine; Chipault, Jennifer G.; White, C. LeAnn; Zuckerberg, Benjamin

2018-01-01

Since the 1960s, periodic outbreaks of avian botulism type E have contributed to large-scale die-offs of thousands of waterbirds throughout the Great Lakes of the United States. In recent years, these events have become more common and widespread. Occurring during the summer and autumn months, the prevalence of these die-offs varies across years and is often associated with years of warmer lake temperatures and lower water levels. Little information exists on how environmental conditions mediate the spatial and temporal characteristics of mortality events.In 2010, a citizen science programme, Avian Monitoring for Botulism Lakeshore Events (AMBLE), was launched to enhance surveillance efforts and detect the appearance of beached waterbird carcasses associated with avian botulism type E outbreaks in northern Lake Michigan. Using these data, our goal was to quantify the within-year characteristics of mortality events for multiple species, and to test whether the synchrony of these events corresponded to fluctuations in two environmental factors suspected to be important in the spread of avian botulism: water temperature and the prevalence of green macroalgae.During two separate events of mass waterbird mortality, we found that the detection of bird carcasses was spatially synchronized at scales of c. 40 km. Notably, the extent of this spatial synchrony in avian mortality matched that of fluctuations in lake surface water temperatures and the prevalence of green macroalgae.Synthesis and applications. Our findings are suggestive of a synchronizing effect where warmer lake temperatures and the appearance of macroalgae mediate the characteristics of avian mortality. In future years, rising lake temperatures and a higher propensity of algal masses could lead to increases in the magnitude and synchronization of avian mortality due to botulism. We advocate that citizen-based monitoring efforts are critical for identifying the potential environmental conditions associated

National Water-Quality Assessment Program - Western Lake Michigan Drainage Basin

USGS Publications Warehouse

Setmire, J.O.

1991-01-01

A major component of the program is study-unit investigations, which comprise the princ ipal bui lding blocks of the program on which national-level asses ment activities a re based . The 60 study-unit in vestigations that make up the program are hydrologic systems that include parts of most major river bas ins and a qui fer systems. These study units cover areas of I ,200 to more than 65 ,000 square mi les and incorporate about 60 to 70 percent of the Nation's water use and popul ation e rved by public water supply. In 1991 , the Western Lake Michigan drainage basin was among the fir st 20 NA WQA study unit selected for study under the full -scale implementation plan.

Water quality in the Western Lake Michigan Drainages, Wisconsin and Michigan, 1992-95

USGS Publications Warehouse

Peters, Charles A.; Robertson, Dale M.; Saad, David A.; Sullivan, Daniel J.; Scudder, Barbara C.; Fitzpatrick, Faith A.; Richards, Kevin D.; Stewart, Jana S.; Fitzgerald, Sharon A.; Lenz, Bernard N.

1998-01-01

This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the Western Lake Michigan Drainages Study Unit and torelate these findings to water-quality issues of regional and national concern. The information in primarily intended for those who are involved in water-resource management. Yet, the information contained here may also interest those who simply wish to know more about the quality of water in the rivers and aquifers in the area where they live.

Surficial deposits in the Bear Lake Basin

USGS Publications Warehouse

Reheis, Marith C.; Laabs, Benjamin J.C.; Forester, Richard M.; McGeehin, John P.; Kaufman, Darrell S.; Bright, Jordon

2005-01-01

Mapping and dating of surficial deposits in the Bear Lake drainage basin were undertaken to provide a geologic context for interpretation of cores taken from deposits beneath Bear Lake, which sometimes receives water and sediment from the glaciated Bear River and sometimes only from the small drainage basin of Bear Lake itself. Analyses of core sediments by others are directed at (1) constructing a high-resolution climate record for the Bear Lake area during the late Pleistocene and Holocene, and (2) investigating the sources and weathering history of sediments in the drainage basin. Surficial deposits in the upper Bear River and Bear Lake drainage basins are different in their overall compositions, although they do overlap. In the upper Bear River drainage, Quaternary deposits derived from glaciation of the Uinta Range contain abundant detritus weathered from Precambrian quartzite, whereas unglaciated tributaries downstream mainly contribute finer sediment weathered from much younger, more friable sedimentary rocks. In contrast, carbonate rocks capped by a carapace of Tertiary sediments dominate the Bear Lake drainage basin.

Impacts on water quality and biota from natural acid rock drainage in Colorado's Lake Creek watershed

USGS Publications Warehouse

Bird, D.A.; Sares, Matthew A.; Policky, Greg A.; Schmidt, Travis S.; Church, Stan E.

2006-01-01

Colorado's Lake Creek watershed hosts natural acid rock drainage that significantly impacts surface water, streambed sediment, and aquatic life. The source of the ARD is a group of iron-rich springs that emerge from intensely hydrothermally altered, unexploited, low-grade porphyry copper mineralization in the Grizzly Peak Caldera. Source water chemistry includes pH of 2.5 and dissolved metal concentrations of up to 277 mg/L aluminum, 498 mg/L iron, and 10 mg/L copper. From the hydrothermally altered area downstream for 27 kilometers to Twin Lakes Reservoir, metal concentrations in streambed sediment are elevated and the watershed experiences locally severe adverse impacts to aquatic life due to the acidic, metal-laden water. The water and sediment quality of Twin Lakes Reservoir is sufficiently improved that the reservoir supports a trout fishery, and remnants of upstream ARD are negligible.

Large rock-slope failures impacting on lakes - Reconstruction of events and deciphering mobility processes at Lake Oeschinen (CH) and Lake Eibsee (D)

NASA Astrophysics Data System (ADS)

Knapp, Sibylle; Anselmetti, Flavio; Gilli, Adrian; Krautblatter, Michael; Hajdas, Irka

2017-04-01

Among single event landslide disasters large rock-slope failures account for 75% of disasters with more than 1000 casualties. The precise determination of recurrence rates and failure volumes combined with an improved understanding of mobility processes are essential to better constrain runout models and establish early warning systems. Here we present the data sets from the two alpine regions Lake Oeschinen (CH) and Lake Eibsee (D) to show how lake studies can help to decipher the multistage character of rock-slope failures and to improve the understanding of the processes related to rock avalanche runout dynamics. We focus on such that impacted on a (paleo-) lake for two main reasons. First, the lake background sedimentation acts as a natural chronometer, which enables the stratigraphic positioning of events and helps to reconstruct the event history. This way it becomes possible to (i) decipher the multistage character of the failure of a certain rock slope and maybe detect progressive failure, (ii) determine the recurrence rates of failures at that certain rock slope, and (iii) consider energies based on estimated failure volumes, fall heights and deposition patterns. Hence, the interactions between a rock-slope failure, the water reservoir and the altered rock-slope are better understood. Second, picturing a rock avalanche running through and beyond a lake, we assume the entrainment of water and slurry to be crucial for the subsequent flow dynamics. The entrainment consumes a large share of the total energy, and orchestrates the mobility leading to fluidization, a much higher flow velocity and a longer runout-path length than expected. At Lake Oeschinen (CH) we used lake sediment cores and reflection seismic profiles in order to reconstruct the 2.5 kyrs spanning rock-slope failure history including 10 events, six of which detached from the same mountain flank, and correlated them with (pre-) historical data. The Lake Eibsee records provide insights into the

Inventory of drainage wells and potential sources of contaminants to drainage-well inflow in Southwest Orlando, Orange County, Florida

USGS Publications Warehouse

Taylor, George Fred

1993-01-01

Potential sources of contaminants that could pose a threat to drainage-well inflow and to water in the Floridan aquifer system in southwest Orlando, Florida, were studied between October and December 1990. Drainage wells and public-supply wells were inventoried in a 14-square-mile area, and available data on land use and activities within each drainage well basin were tabulated. Three public-supply wells (tapping the Lower Floridan aquifer) and 38 drainage wells (open to the Upper Floridan aquifer) were located in 17 drainage basins within the study area. The primary sources of drainage-well inflow are lake overflow, street runoff, seepage from the surficial aquifer system, and process-wastewater disposal. Drainage-well inflow from a variety of ares, including resi- dential, commercial, undeveloped, paved, and industrial areas, are potential sources of con- taminants. The four general types of possible contaminants to drainage-well inflow are inorganic chemicals, organic compounds, turbidity, and microbiological contaminants. Potential contami- nant sources include plant nurseries, citrus groves, parking lots, plating companies, auto- motive repair shops, and most commonly, lake- overflow water. Drainage wells provide a pathway for contaminants to enter the Upper Floridan aquifer and there is a potential for contaminants to move downward from the Upper Floridan to the Lower Floridan aquifer.

Modelling nutrient fluxes from diffuse and point emissions to river loads: the Estonian part of the transboundary Lake Peipsi/Chudskoe drainage basin (Russia/Estonia/Latvia).

PubMed

Mourad, D; van der Perk, M

2004-01-01

First results are presented of a large-scale GIS-based nutrient transport modelling for the 1985-1999 period in the Estonian part of the transboundary drainage basin of Lake Peipsi (Estonian)/Chudskoe (Russian), one of the largest lakes in Europe, shared by Russia and Estonia. Although the lake is relatively undisturbed by human pollution, it is vulnerable for eutrophication by increased river loads, as shown in the past, when the north-eastern part of the former Soviet Union suffered from intensive agriculture. The collapse of the Soviet Union caused a dramatic decline in fertilizer application rates and widespread abandonment of agricultural land. Although concentration measurements and modelling results indicate a general decrease in nutrient loads, modelling is complicated by the transfer of nutrients from diffuse emissions, which is strongly governed by retention and assumed periodic release from storages within the river basin, like the root zone, tile drains, ditches, channels, bed sediments, floodplains and lakes. Modelling diffuse emission contribution to river loads can be improved by better knowledge about the spatial and temporal distribution of this retention and release within the drainage basin.

The influence of hydrologic residence time on lake carbon cycling dynamics following extreme precipitation events

Treesearch

Jacob A. Zwart; Stephen D. Sebestyen; Christopher T. Solomon; Stuart E. Jones

2016-01-01

The frequency and magnitude of extreme events are expected to increase in the future, yet little is known about effects of such events on ecosystem structure and function. We examined how extreme precipitation events affect exports of terrestrial dissolved organic carbon (t-DOC) from watersheds to lakes as well as in-lake heterotrophy in three north-temperate lakes....

Reconstructing Heat Fluxes Over Lake Erie During the Lake Effect Snow Event of November 2014

NASA Astrophysics Data System (ADS)

Fitzpatrick, L.; Fujisaki-Manome, A.; Gronewold, A.; Anderson, E. J.; Spence, C.; Chen, J.; Shao, C.; Posselt, D. J.; Wright, D. M.; Lofgren, B. M.; Schwab, D. J.

2017-12-01

The extreme North American winter storm of November 2014 triggered a record lake effect snowfall (LES) event in southwest New York. This study examined the evaporation from Lake Erie during the record lake effect snowfall event, November 17th-20th, 2014, by reconstructing heat fluxes and evaporation rates over Lake Erie using the unstructured grid, Finite-Volume Community Ocean Model (FVCOM). Nine different model runs were conducted using combinations of three different flux algorithms: the Met Flux Algorithm (COARE), a method routinely used at NOAA's Great Lakes Environmental Research Laboratory (SOLAR), and the Los Alamos Sea Ice Model (CICE); and three different meteorological forcings: the Climate Forecast System version 2 Operational Analysis (CFSv2), Interpolated observations (Interp), and the High Resolution Rapid Refresh (HRRR). A few non-FVCOM model outputs were also included in the evaporation analysis from an atmospheric reanalysis (CFSv2) and the large lake thermodynamic model (LLTM). Model-simulated water temperature and meteorological forcing data (wind direction and air temperature) were validated with buoy data at three locations in Lake Erie. The simulated sensible and latent heat fluxes were validated with the eddy covariance measurements at two offshore sites; Long Point Lighthouse in north central Lake Erie and Toledo water crib intake in western Lake Erie. The evaluation showed a significant increase in heat fluxes over three days, with the peak on the 18th of November. Snow water equivalent data from the National Snow Analyses at the National Operational Hydrologic Remote Sensing Center showed a spike in water content on the 20th of November, two days after the peak heat fluxes. The ensemble runs presented a variation in spatial pattern of evaporation, lake-wide average evaporation, and resulting cooling of the lake. Overall, the evaporation tended to be larger in deep water than shallow water near the shore. The lake-wide average evaporations

Sediment sequences and palynology of outer South Bay, Manitoulin Island, Ontario: Connections to Lake Huron paleohydrologic phases and upstream Lake Agassiz events

NASA Astrophysics Data System (ADS)

Lewis, C. F. M.; Anderson, T. W.

2017-10-01

South Bay on the southern coast of Manitoulin Island is a fjord-like embayment connected to Lake Huron by a natural narrow gap in the bay's outer sill 6.5-14 m above the lake. A seismic profile, pollen, plant macrofossil, grain size analyses, and other sediment properties of two piston cores from a shallow outer basin of the bay document a 9 m-thick sediment section comprising rhythmically laminated clay under silty clay containing zones with small molluscan shells and marsh detritus. A sandy pebbly layer under soft silty clay mud overlies these sediments. This stratigraphy represents inundation by deep glacial Lake Algonquin followed by the shallowing Post Algonquin series of lakes, and exposure in the early Holocene by 5 Lake Stanley lowstands in the Lake Huron basin separated by 4 Lake Mattawa highstands. Overflow from South Bay in the first lowstand is thought to have eroded the outer sill gap. Marsh environments are inferred to have formed in the bay during subsequent lowstands. The Lake Mattawa highstands are attributed to outburst floods mainly from glacial Lake Agassiz. Palynological evidence of increased spruce occurrence, an apparent regional climate reversal, during the dry pine period is attributed to cold northwest winds from the Lake Superior basin and a lake effect from the Mattawa highstands in the Lake Huron basin. Lake waters transgressed South Bay following the pine period to form the Nipissing shore on Manitoulin Island. Transfer of Lake Huron basin drainage to southern outlets and continued glacioisostatic uplift of the region led to the present configuration of South Bay and Lake Huron.

Pluvial lakes in the Great Basin of the western United States: a view from the outcrop

USGS Publications Warehouse

Reheis, Marith C.; Adams, Kenneth D.; Oviatt, Charles G.; Bacon, Steven N.

2014-01-01

Paleo-lakes in the western United States provide geomorphic and hydrologic records of climate and drainage-basin change at multiple time scales extending back to the Miocene. Recent reviews and studies of paleo-lake records have focused on interpretations of proxies in lake sediment cores from the northern and central parts of the Great Basin. In this review, emphasis is placed on equally important studies of lake history during the past ∼30 years that were derived from outcrop exposures and geomorphology, in some cases combined with cores. Outcrop and core records have different strengths and weaknesses that must be recognized and exploited in the interpretation of paleohydrology and paleoclimate. Outcrops and landforms can yield direct evidence of lake level, facies changes that record details of lake-level fluctuations, and geologic events such as catastrophic floods, drainage-basin changes, and isostatic rebound. Cores can potentially yield continuous records when sampled in stable parts of lake basins and can provide proxies for changes in lake level, water temperature and chemistry, and ecological conditions in the surrounding landscape. However, proxies such as stable isotopes may be influenced by several competing factors the relative effects of which may be difficult to assess, and interpretations may be confounded by geologic events within the drainage basin that were unrecorded or not recognized in a core. The best evidence for documenting absolute lake-level changes lies within the shore, nearshore, and deltaic sediments that were deposited across piedmonts and at the mouths of streams as lake level rose and fell. We review the different shorezone environments and resulting deposits used in such reconstructions and discuss potential estimation errors. Lake-level studies based on deposits and landforms have provided paleohydrologic records ranging from general changes during the past million years to centennial-scale details of fluctuations during the

Multimillion-Year Evolution of a Sublacustrine Fan System: Source-to-Sink History of the South Rukuru and Ruhuhu River Drainages, Lake Malawi (Nyasa) Rift, East Africa

NASA Astrophysics Data System (ADS)

Scholz, C. A.; Shillington, D. J.; McCartney, T.

2017-12-01

The development of long-lived continental rifts can be markedly influenced by surface processes, including sediment input and footwall erosion. This occurs through modifying crustal thickness and loading, as well as by influencing behaviors of individual faults. Here we report on the evolution of a long-lived system of sublacustrine fans in the Central Basin of the Lake Malawi (Nyasa) rift, East Africa. An extensive suite of crustal-scale seismic reflection data was acquired in 2015 as part of the SEGMeNT project, which resulted superb images of the syn-rift section. These data are augmented by legacy single-channel high resolution reflection data that provide detailed information on facies geometries and stacking architecture of the deep-water fan systems. The ages and lithologic character of the stratal surfaces observed in the reflection seismic data are constrained by ties to the 2005 scientific drill cores acquired during the Lake Malawi Scientific Drilling Project. The South Rukuru River is an eastward flowing regional drainage (11,900 km2) that enters Lake Malawi through an incision in the western border fault of the rift's Central Basin. The Rukuru River drainage (17,230 km2) enters the eastern side of the lake at an accommodation zone margin between the North and Central Basins. Both are antecedent drainages that prior to rifting may have delivered sediments to the Indian Ocean continental margin. Both systems now deliver sediment to a highly confined and focused depocenter in the Central Basin. The complex interplay of extension, mainly on the border fault systems, and high-frequency and high-amplitude lake levels shifts, has led to unique coarse sediment facies stacking architectures, with vertical stacking controlled by hydroclimate, and lateral positioning localized by fault behavior. Focused deep-water (700 m) deposition has resulted in overpressure within the sedimentary section in the localized depocenter, producing dramatic mud diapirs. Long

Environmental setting of fixed sites in the western Lake Michigan drainages, Michigan and Wisconsin

USGS Publications Warehouse

Sullivan, D.J.; Peterson, E.M.; Richards, K.D.

1995-01-01

This report describes selected environmental- setting features for 11 fixed surface-water sites in the Western Lake Michigan Drainages study unit of the National Water-Quality Assessment Pro- gram. The study unit, which includes 10 major river systems draining to Lake Michigan, is bounded on the south by the Illinois State line and extends north to about 31 miles north of Escanaba, Mich. The fixed sites are on the following streams: Peshekee River, Popple River, Menominee River, Pensaukee River, Duck Creek, Tomorrow River, East River, Fox River, North Branch Milwaukee River, Lincoln Creek, and Milwaukee River. Drainage basins above these sites receive runoff from land uses and land covers, bedrock types, and surficial deposits representative of the main types of each of these characteristics in the study unit. Data types collected at the fixed sites include water chemistry; organic compounds and trace elements in streambed sediment and biological tissues; algal, benthic-invertebrate, and fish communities; and aquatic habitat. Field measurements include water temperature, pH, specific conductance, alkalinity, and dissolved oxygen. Results of water- quality field measurements indicate little variation in temperature among the fixed sites. Specific conductance and alkalinity were generally higher at sites underlain by carbonate bedrock than at sites underlain by igneous/metamorphic bedrock. Differences in pH among the fixed sites were less than those for specific conductance and alkalinity, but pH seemed to increase slightly from north to south. Dissolved-oxygen concentration varied more at agricultural sites than at forested and urban sites, perhaps because of higher nutrient inputs at agricultural sites. The information included in this report has been assembled as reference material for ongoing studies at the fixed sites.

Areal distribution and concentrations of contaminants of concern in surficial streambed and lakebed sediments, Lake Erie-Lake Saint Clair Drainages, 1990-97

USGS Publications Warehouse

Rheaume, S.J.; Button, D.T.; Myers, Donna N.; Hubbell, D.L.

2001-01-01

Concerns about elevated concentrations of contaminants such as polychlorinated biphenyls and mercury in aquatic bed sediments throughout the Great Lakes Basin have resulted in a need for better understanding of the scope and severity of the problem. Various organochlorine pesticides, polychlorinated biphenyls, trace metals, and polycyclic aromatic hydrocarbons are a concern because of their ability to persist and accumulate in aquatic sediments and their association with adverse aquatic biological effects. The areal distribution and concentrations in surficial bed sediments of 20 contaminants of concern with established bed-sediment-toxicity guidelines were examined in relation to their potential effects on freshwater aquatic biota. Contaminants at more than 800 sampling locations are characterized in this report. Surficial bed-sediment-quality data collected from 1990 to 1997 in the Lake Erie?Lake Saint Clair Drainages were evaluated to reflect recent conditions. In descending order, concentrations of total polycyclic aromatic hydrocarbons, phenanthrene, total polychlorinated biphenyls, chrysene, benz[a]anthracene, benzo[a]pyrene, cadmium, lead, zinc, arsenic, and mercury were the contaminants that most commonly exceeded levels associated with probable adverse effects on aquatic benthic organisms. The highest concentrations of most of these contaminants in aquatic bed sediments are confined to the 12 specific geographic Areas of Concern identified in the 1987 Revisions to the Great Lakes Water Quality Agreement of 1972. An exception is arsenic, which was detected at concentrations exceeding threshold effect levels at many locations outside Areas of Concern.

Meteotsunamis in the Great Lakes and Investigation into the May 27, 2012 Event on Lake Erie

NASA Astrophysics Data System (ADS)

Anderson, E. J.; Bechle, A.; Wu, C. H.; Schwab, D. J.; Mann, G.

2016-02-01

Meteotsunami events have been documented in several countries around the world in the coastal ocean, semi-enclosed basins, and in the Great Lakes. In particular, investigations in the Great Lakes have raised the issue of dangers posed by enclosed basins due to the reflection and interaction of meteotsunami waves, in which the destructive waves can arrive several hours after the atmospheric disturbance has passed. This disassociation in time and space between the atmospheric disturbance and resultant meteotsunami wave can pose a significant threat to the public. In a recent event on May 27, 2012, atmospheric conditions gave rise to two convective systems that generated a series of waves in the meteotsunami band on Lake Erie. The resulting waves swept three swimmers a half-mile offshore, inundated a marina, and may have led to a capsized boat along the southern shoreline. Examination of the observed conditions shows that these events occurred at a time between the arrivals of these two storm systems when atmospheric conditions were relatively calm but water level displacements were at their greatest. In this work, we attempt to explain the processes that led to these conditions through a combination of atmospheric and hydrodynamic modeling and an analysis of the observed radial velocities associated with the meteotsunami-inducing front. Results from a high-resolution atmospheric model and hydrodynamic model reveal that the formation of these destructive waves resulted from a combination of wave reflection, focusing, and edge waves that impacted the southern shore of Lake Erie. This event illustrates the unique danger posed by temporal lags between the inducing atmospheric conditions and resulting dangerous nearshore wave conditions.

Towards monitoring surface and subsurface lakes on the Greenland Ice Sheet using Sentinel-1 SAR and Landsat-8 OLI imagery

NASA Astrophysics Data System (ADS)

Miles, Katie E.; Willis, Ian C.; Benedek, Corinne L.; Williamson, Andrew G.; Tedesco, Marco

2017-07-01

Supraglacial lakes are an important component of the Greenland Ice Sheet’s mass balance and hydrology, with their drainage affecting ice dynamics. This study uses imagery from the recently launched Sentinel-1A Synthetic Aperture Radar (SAR) satellite to investigate supraglacial lakes in West Greenland. A semi-automated algorithm is developed to detect surface lakes from Sentinel-1 images during the 2015 summer. A combined Landsat-8 and Sentinel-1 dataset, which has a comparable temporal resolution to MODIS (3 days versus daily) but a higher spatial resolution (25-40 m versus 250-500 m), is then used together with a fully-automated lake drainage detection algorithm. Rapid (< 4 days) and slow (> 4 days) drainages are investigated for both small (< 0.125 km2, the minimum size detectable by MODIS) and large (≥ 0.125 km2) lakes through the summer. Drainage events of small lakes occur at lower elevations (mean 159 m), and slightly earlier (mean 4.5 days) in the melt season than those of large lakes. The analysis is extended manually into the early winter to calculate the dates and elevations of lake freeze-through more precisely than is possible with optical imagery (mean 30 August; 1270 m mean elevation). Finally, the Sentinel-1 imagery is used to detect subsurface lakes and, for the first time, their dates of appearance and freeze-through (mean 9 August and 7 October, respectively). These subsurface lakes occur at higher elevations than the surface lakes detected in this study (mean 1593 m and 1185 m, respectively). Sentinel-1 imagery therefore provides great potential for tracking melting, water movement and freezing within both the firn zone and ablation area of the Greenland Ice Sheet.

Landslide-generated tsunamis in a perialpine lake: Historical events and numerical models

NASA Astrophysics Data System (ADS)

Hilbe, Michael; Anselmetti, Flavio S.

2014-05-01

Many of the perialpine lakes in Central Europe - the large, glacier-carved basins formed during the Pleistocene glaciations of the Alps - have proven to be environments prone to subaquatic landsliding. Among these, Lake Lucerne (Switzerland) has a particularly well-established record of subaquatic landslides and related tsunamis. Its sedimentary archive documents numerous landslides over the entire Holocene, which have either been triggered by earthquakes, or which occurred apparently spontaneously, possibly due to rapid sediment accumulation on delta slopes. Due to their controlled boundary conditions and the possibility to be investigated on a complete basinal scale, such lacustrine tsunamis may be used as textbook analogons for their marine counterparts. Two events in the 17th century illustrate these processes and their consequences: In AD 1601, an earthquake (Mw ~ 5.9) led to widespread failure of the sediment drape covering the lateral slopes in several basins. The resulting landslides generated tsunami waves that reached a runup of several metres, as reported in historical accounts. The waves caused widespread damage as well as loss of lives in communities along the shores. In AD 1687, the apparently spontaneous collapse of a river delta in the lake led to similar waves that damaged nearby villages. Based on detailed information on topography, bathymetry and the geometry of the landslide deposits, numerical simulations combining two-dimensional, depth-averaged models for landslide propagation, as well as for tsunami generation, propagation and inundation, are able to reproduce most of the reported tsunami effects for these events. Calculated maximum runup of the waves is 6 to >10 m in the directly affected lake basins, but significantly less in neighbouring basins. Flat alluvial plains adjacent to the most heavily affected areas are inundated over distances of several hundred metres. Taken as scenarios for possible future events, these past events suggest

Observations of Lake-Breeze Events During the Toronto 2015 Pan-American Games

NASA Astrophysics Data System (ADS)

Mariani, Zen; Dehghan, Armin; Joe, Paul; Sills, David

2018-01-01

Enhanced meteorological observations were made during the 2015 Pan and Parapan American Games in Toronto in order to measure the vertical and horizontal structure of lake-breeze events. Two scanning Doppler lidars (one fixed and one mobile), a C-band radar, and a network including 53 surface meteorological stations (mesonet) provided pressure, temperature, humidity, and wind speed and direction measurements over Lake Ontario and urban areas. These observations captured the full evolution (prior, during, and after) of 27 lake-breeze events (73% of observation days) in order to characterize the convective and dynamic processes driving lake breezes at the local scale and mesoscale. The dominant signal of a passing lake-breeze front (LBF) was an increase in dew-point temperature of 2.3 ± 0.3°C, coinciding with a 180° shift in wind direction and a decrease in air temperature of 2.1 ± 0.2°C. Doppler lidar observations over the lake detected lake breezes 1 hour (on average) before detection by radar and mesonet. On days with the synoptic flow in the offshore direction, the lidars observed wedge-shaped LBFs with shallow depths, which inhibited the radar's ability to detect the lake breeze. The LBF's ground speed and inland penetration distance were found to be well-correlated (r = 0.78), with larger inland penetration distances occurring on days with non-opposing (non-offshore) synoptic flow. The observed enhanced vertical motion ({>} 1 m s^{-1}) at the LBF, observed by the lidar on 54% of lake-breeze days, was greater (at times {>} 2.5 m s^{-1}) than that observed in previous studies and longer-lasting over the lake than over land. The weaker and less pronounced lake-breeze structure over land is illustrated in two case studies highlighting the lifetime of the lake-breeze circulation and the impact of propagation distance on lake-breeze intensity.

A linked lake system beneath Thwaites Glacier, West Antarctica reveals an efficient mechanism for subglacial water flow.

NASA Astrophysics Data System (ADS)

Smith, B. E.; Gourmelen, N.; Huth, A.; Joughin, I. R.

2016-12-01

In this presentation we show the results of a multi-sensor survey of a system of subglacial lakes beneath Thwaites Glacier, West Antarctica. This is the first substantial active (meaning draining or filling on annual time scales) lake system detected under the fast-flowing glaciers of the Amundsen Coast. Altimetry data show that over the 2013 calendar year, four subglacial lakes drained, essentially simultaneously, with the bulk of the drainage taking place over the course the first three months of the year. The largest of the lakes appears to have drained around 3.7 km3 of water, with the others each draining less than 1 km3. The high-resolution radar surveys conducted in this area by NASA's IceBridge program allow detailed analysis of the subglacial hydrologic potential, which shows that the potential map in this area is characterized by small closed basins that should not, under the common assumption that water flow is directed down the gradient of the hydropotential, allow long-range water transport. The lakes' discharge demonstrates that, at least in some cases, water can flow out of apparently closed hydropotential basins. Combining a basal-flow routing map with a map of basal melt production suggests that the largest drainage event could recur as often as every 22 years, provided that overflow or leakage of mapped hydropotential basins allows melt water transport to refill the lake. An analysis of ice-surface speed records both around the lakes and at the Thwaites grounding line shows small changes in ice speed, but none clearly associated with the drainage event, suggesting that, at least in this area where subglacial melt is abundant, the addition of further water to the subglacial hydrologic system need not have any significant effect on ice flow. It is likely that the main impact of the lake system on the glacier is that as an efficient mechanism to remove meltwater from the system, it drains water that would otherwise flow through less efficient

Modeling salinization and recovery of road salt-impacted lakes in temperate regions based on long-term monitoring of Lake George, New York (USA) and its drainage basin.

PubMed

Sutherland, J W; Norton, S A; Short, J W; Navitsky, C

2018-05-08

Road salt mitigates winter highway icing but accumulates in watershed soils and receiving waters, affecting soil chemistry and physical, biological, and ecological processes. Despite efforts to reduce salt loading in watersheds, accumulated cations and Cl - continue to impact tributaries and lakes, and the recovery process is not well understood. Lake George, New York (USA) is typical of many temperate lakes at risk for elevated Cl - concentrations from winter deicing; the lake salt concentration increased by ~3.4% year -1 since 1980. Here, we evaluated the ionic composition in Finkle Brook, a major watershed draining to Lake George, studied intermittently since 1970 and typical of other salt-impacted Lake George tributaries. Salt loading in the Lake George basin since the 1940s displaced cations from exchange sites in basin soils; these desorbed cations follow a simple ion-exchange model, with lower sodium and higher calcium, magnesium and potassium fluxes in runoff. Reduced salt application in the Finkle Brook watershed during the low-snow winter of 2015-2016 led to a 30-40% decline of Cl - and base cations in the tributary, implying a Cl - soil half-life of 1-2 years. We developed a conceptual model that describes cation behavior in runoff from a watershed that received road salt loading over a long period of time, and then recovery following reduced salt loading. Next, we developed a dynamic model estimating time to steady-state for Cl - in Lake George with road salt loading starting in 1940, calibrating the model with tributary runoff and lake chemistry data from 1970 and 1980, respectively, and forecasting Cl - concentrations in Lake George based on various scenarios of salt loading and soil retention of Cl - . Our Lake George models are readily adaptable to other temperate lakes with drainage basins where road salt is applied during freezing conditions and paved roads cover a portion of the watershed. Copyright © 2018 Elsevier B.V. All rights reserved.

Seismic Response of the Greenland Ice-sheet over Several Melt Seasons near Draining Supraglacial Lakes

NASA Astrophysics Data System (ADS)

Carmichael, J. D.; Joughin, I. R.; Behn, M. D.; Das, S. B.; Lizarralde, D.

2012-12-01

We present seismic observations assembled from 3+ years of melt season measurements collected near seasonally-draining supraglacial lakes on the Greenland Ice-sheet (68.7311,-49.5925). On transient time scales (< 1 day), these data include a record of seismic response coincident with at least three documented lake drainage events. During a particular event, drainage is preceded by two hours of impulsive high-energy seismic signals, followed by the onset of continuous broadband signals (2-50Hz) that we interpret as surface-to-bed meltwater transfer. This drainage is followed additional transient icequakes similar in timing and energy to the precursory activity. Over a seasonal time scale (> 1 month), our data records a transition in seismicity between two distinct modes, with one mode characterized by relative quiescence, and the other mode characterized by uniform energy that is observed network-wide as a continuous, repetitive signal. The transition between modes is abrupt (~ 2 hours) and is observed using multiple seismic discriminants. We interpret this rapid transition as reflecting the evolution of the morphology of a basal drainage system as it responds to melt input. This interpretation is tested against additional geophysical observations that include temperature-based melt models, satellite imagery, and GPS measurements. Finally, we outline and advocate a routine for monitoring icesheet seismicity with a focus on distinguishing surface from basal sources.

Determination of Flood Discharges in Rivers as a Prerequisite for Calculating Rates of Geomorphic Change in Drainage Basins During Extreme Events

NASA Astrophysics Data System (ADS)

Smith, J. D.; Kean, J. W.

2003-12-01

Accurate empirical determination of river discharge during an extreme event is very difficult even at a gage site. Moreover, the procurement of extreme flow measurements at many locations in an ungaged drainage basin often is necessary to relate the surface-water flow in the drainage network during a flood to the spatial distribution of intense rainfall. Consequently, paleo-hydrologic methods have to be employed to estimate peak discharges. These methods, however, require the application of some type of flow model. Often the flow models used with paleo-hydrologic data are over simplified and embody low-flow or extrapolated roughness coefficients that are inappropriate for the high flow of interest and that substantially reduce the reliability of the estimated discharge. Models that permit calculation of flow resistance from measured or calculated pre-flood, post-flood, or evolving channel and floodplain geometries and roughnesses can yield the most accurate results for these extreme situations. We have developed a procedure for directly calculating flow discharge as a function of stage in reaches a few tens of river widths in length. The foundation for this approach is a set of algorithms that permits computation of the form drag on topographic elements and woody vegetation. Its application requires an initial survey of the channel and floodplain topography and roughness. The method can be used either with stage determined from a set of pressure gages distributed throughout a drainage basin to monitor discharge in a drainage network or with paleo-hydrologic data to determine discharge from extreme events. Currently, our method of determining discharge from stage is being tested at various sites in the drainage basin of the Whitewater River, Kansas. Two of these sites are just downstream of USGS gages, and a third is a short distance downstream from the outlet pipe of a man-made lake. These tests are for a full range of hydrologic conditions in order to demonstrate

Geomorphic Drainage Capture Recorded by Oxygen Isotopes of Green River Formation Lacustrine Mudstone, Eocene, Wyoming

NASA Astrophysics Data System (ADS)

Doebbert, A. C.; Booth, A. L.; Carroll, A.; Chamberlain, C.; Rhodes, M.

2005-12-01

The isotopic composition of cement and other meteoric precipitates are increasingly being used to interpret orogenic uplift histories, based on the relationship between altitude and rainwater δ18O. However, other variables such as changing regional drainage patterns may also affect the downstream composition of surface waters, especially when multiple drainages commingle in a lake. The Green River Formation contains some of the best documented lacustrine deposits in the world, making it ideal for examining such issues. Carbonate mudstone in balanced-fill facies of the lower LaClede Bed averages 3.41‰ (PDB), and records a deep, saline to brackish lake that fluctuated near its sill. In contrast, overfilled facies of the upper LaClede Bed record a freshwater lake, and δ18O reaches values as low as -9.72‰. This transition occurred shortly after deposition of the Analcite Tuff at 48.94 ± 0.12 Ma (Smith et al., 2003), and was geologically abrupt. Based on 40Ar/39Ar-calibrated sediment accumulation rates it required no more than 200-300 ky. An almost identical transition occurs in two cores separated by about 30 km, making local diagenesis an unlikely cause. The magnitude of δ18O change is similar to that in some uplift studies, but its rapidity virtually excludes uplift as a controlling mechanism. Instead, we propose that both the change in sedimentation and the sharp decrease in δ18O are the result of a drainage capture event. The addition of a new drainage to the basin may have adjusted isotopic values in two ways: by introducing runoff with relatively low δ18O, and by decreasing residence time (and therefore evaporation) of lake water. Decreasing 87Sr/86Sr across the same transition suggests that the newly added waters may have been sourced from rising volcanic topography to the north in the Absaroka province. Although this rising topography allows for the possibility of some uplift component, the rate of change in lacustrine δ18O is consistent with

Water-quality assessment of the western Lake Michigan drainages; analysis of available information on nutrients and suspended sediment, water years 1971-90

USGS Publications Warehouse

Robertson, Dale M.; Saad, D.A.

1996-01-01

To fulfill the goals of the NAWQA program, the USGS plans to examine 60 areas (study units) across the United States during full implementation of the program. In 1991, the NAWQA program went into full implementation with the intensive investigation of 20 of these study units; one of these study units is the Western Lake Michigan Drainages (WMIC) study unit.

A climatology of extreme wave height events impacting eastern Lake Ontario shorelines

NASA Astrophysics Data System (ADS)

Grieco, Matthew B.; DeGaetano, Arthur T.

2018-05-01

Model-derived wave height data for points along the eastern Lake Ontario shoreline provide the basis for a 36-year climatology of extreme wave heights. The most extreme wave heights exceed 6 m at all locations, except for those along the extreme northeastern shoreline of the Lake. Typically extreme wave events are a regional phenomenon, affecting multiple locations along the eastern and southeastern shoreline. A pronounced seasonal cycle in wave event occurrence is characterized by peaks in autumn and spring, with an absence of 99.9th percentile wave heights during summer. Less extreme (90th percentile heights) occur in all months with a peak in winter. Extreme wave events are most often associated with a low pressure center tracking to the north of Lake Ontario from the Ohio Valley. This track produces the strong winds > 10 ms-1 and predominantly west-to-east wind fetch that characterize high wave height events. The seasonal frequency of the wave events exceeding the historical 95th percentile has shown a statistically significant increase at most locations since 1979. This has been partially offset by declines in the frequency of events with wave heights between the 90 and 95th percentile. Seasonal extreme wave height frequency is also found to be related to the occurrence of El Niño. During El Niño winters, there are significantly fewer events with wave heights exceeding 2.5 m than would be expected by chance. A corresponding relationship to La Niña occurrence is not evident.

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.

Significant seasonal variations of microbial community in an acid mine drainage lake in Anhui Province, China.

PubMed

Hao, Chunbo; Wei, Pengfei; Pei, Lixin; Du, Zerui; Zhang, Yi; Lu, Yanchun; Dong, Hailiang

2017-04-01

Acid mine drainage (AMD),characterized by strong acidity and high metal concentrations, generates from the oxidative dissolution of metal sulfides, and acidophiles can accelerate the process significantly. Despite extensive research in microbial diversity and community composition, little is known about seasonal variations of microbial community structure (especially micro eukaryotes) in response to environmental conditions in AMD ecosystem. To this end, AMD samples were collected from Nanshan AMD lake, Anhui Province, China, over a full seasonal cycle from 2013 to 2014, and water chemistry and microbial composition were studied. pH of lake water was stable (∼3.0) across the sampling period, while the concentrations of ions varied dramatically. The highest metal concentrations in the lake were found for Mg and Al, not commonly found Fe. Unexpectedly, ultrahigh concentration of chlorophyll a was measured in the extremely acidic lake, reaching 226.43-280.95 μg/L in winter, even higher than those in most eutrophic freshwater lakes. Both prokaryotic and eukaryotic communities showed a strong seasonal variation. Among the prokaryotes, "Ferrovum", a chemolithotrophic iron-oxidizing bacterium was predominant in most sampling seasons, although it was a minor member prior to September, 2012. Fe 2+ was the initial geochemical factor that drove the variation of the prokaryotic community. The eukaryotic community was simple but varied more drastically than the prokaryotic community. Photoautotrophic algae (primary producers) formed a food web with protozoa or flagellate (top consumers) across all four seasons, and temperature appeared to be responsible for the observed seasonal variation. Ochromonas and Chlamydomonas (responsible for high algal bloom in winter) occurred in autumn/summer and winter/spring seasons, respectively, because of their distinct growth temperatures. The closest phylogenetic relationship between Chlamydomonas species in the lake and those in Arctic

The aqueous geochemistry of uranium in a drainage containing uraniferous organic-rich sediments, Lake Tahoe area, Nevada, USA

USGS Publications Warehouse

Zielinski, R.A.; Otton, J.K.; Wanty, R.B.; Pierson, C.T.

1988-01-01

Anomalously uraniferous waters occur in a small (4.2 km2) drainage in the west-central Carson Range, Nevada, on the eastern side of Lake Tahoe. The waters transport uranium from local U-rich soils and bedrock to organic-rich valley-fill sediments where it is concentrated, but weakly bound. The dissolved U and the U that is potentially available from coexisting sediments pose a threat to the quality of drinking water that is taken from the drainage. The U concentration in samples of 6 stream, 11 spring and 7 near-surface waters ranged from 0.1 V). Possible precipitation of U(IV) minerals is predicted under the more reducing conditions that are particularly likely in near-surface waters, but the inhibitory effects of sluggish kinetics or organic complexing are not considered. These combined results suggest that a process such as adsorption or ion exchange, rather than mineral saturation, is the most probable mechanism for uranium fixation in the sediments. -Authors

NPDES Permit for Leadville Mine Drainage Tunnel Treatment Plant in Colorado

EPA Pesticide Factsheets

Under NPDES permit CO-0021717, the U.S. Bureau of Reclamation is authorized to discharge from the Leadville Mine Drainage Tunnel Treatment Plant in Lake County, Colorado to an unnamed drainage way tributary to the East Fork of the Arkansas River.

Drivers of deep-water renewal events observed over 13 years in the South Basin of Lake Baikal

NASA Astrophysics Data System (ADS)

Tsimitri, Chrysanthi; Rockel, Burkhardt; Wüest, Alfred; Budnev, Nikolay M.; Sturm, Michael; Schmid, Martin

2015-03-01

Lake Baikal, with a depth of 1637 m, is characterized by deep-water intrusions that bridge the near-surface layer to the hypolimnion. These episodic events transfer heat and oxygen over large vertical scales and maintain the permanent temperature stratified deep-water status of the lake. Here we evaluate a series of intrusion events that reached the bottom of the lake in terms of the stratification and the wind conditions under which they occurred and provide a new insight into the triggering mechanisms. We make use of long-term temperature and current meter data (2000-2013) recorded in the South Basin of the lake combined with wind data produced with a regional downscaling of the global NCEP-RA1 reanalysis product. A total of 13 events were observed during which near-surface cold water reached the bottom of the South Basin at 1350 m depth. We found that the triggering mechanism of the events is related to the time of the year that they take place. We categorized the events in three groups: (1) winter events, observed shortly before the complete ice cover of the lake that are triggered by Ekman coastal downwelling, (2) under-ice events, and (3) spring events, that show no correlation to the wind conditions and are possibly connected to the increased spring outflow of the Selenga River. This article was corrected on 18 MAR 2015. See the end of the full text for details.

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...

Correlation of Late-Pleistocene Lake-Level Oscillations in Mono Lake, California, with North Atlantic Climate Events

NASA Astrophysics Data System (ADS)

Benson, Larry V.; Lund, Steve P.; Burdett, James W.; Kashgarian, Michaele; Rose, Timothy P.; Smoot, Joseph P.; Schwartz, Martha

1998-01-01

Oxygen-18 ( 18O) values of sediment from the Wilson Creek Formation, Mono Basin, California, indicate three scales of temporal variation (Dansgaard-Oeschger, Heinrich, and Milankovitch) in the hydrologic balance of Mono Lake between 35,400 and 12,900 14C yr B.P. During this interval, Mono Lake experienced four lowstands each lasting from 1000 to 2000 yr. The youngest lowstand, which occurred between 15,500 and 14,000 14C yr B.P., was nearly synchronous with a desiccation of Owens Lake, California. Paleomagnetic secular variation (PSV) data indicate that three of four persistent lowstands occurred at the same times as Heinrich events H1, H2, and H4. 18O data indicate the two highest lake levels occurred ˜18,000 and ˜13,100 14C yr B.P., corresponding to passages of the mean position of the polar jet stream over the Mono Basin. Extremely low values of total inorganic carbon between 26,000 and 14,000 14C yr B.P. indicate glacial activity, corresponding to a time when summer insolation was much reduced.

An Archeological Survey Along the Eastern Floodplain of the Lower Illinois River: Cultural Resource Survey of Selected Portions of the Meredosia and Meredosia Lake Drainage and Levee Districts, Scott, Cass and Morgan Counties, Illinois. St. Louis District Cultural Resource Management Report Number 19

DTIC Science & Technology

1985-03-01

COUNTIES , ILLINOIS CONTRACT NO. DACW4382.D.0083 edited by DTIC Harold Hassen S ELECTE FEB 0 3 1992N CONTRIBUTIONS BY HAROLD HASSEN, ERICH SCHROEDER...SELECTED PORTIONS OF THE MEREDOSIA AND MEREDOSIA LAKE DRAINAGE AND LEVEE DISTRICTS, SCOTT, CASS, AND MORGAN COUNTIES ,,; PERFORMING ORG. REPORT N-.MBER...River: Cultural Resource Survey of Selected Portions of the Meredosia and Meredosia Lake Drainage and Levee Districts, Scott, Cass and Morgan Counties

A catastrophic event in Lake Geneva region during the Early Bronze Age?

NASA Astrophysics Data System (ADS)

Kremer, Katrina; Yrro, Blé; Marillier, François; Hilbe, Michael; Corboud, Pierre; Rachoud-Schneider, Anne-Marie; Girardclos, Stéphanie

2013-04-01

Similarly to steep oceanic continental margins, lake slopes can collapse, producing large sublacustrine landslides and tsunamis. Lake sediments are excellent natural archives of such mass movements and their study allows the reconstructions of these prehistoric events, such as the 563 AD large tsunami over Lake Geneva (Kremer et al, 2012). In Lake Geneva, more than 100 km of high-resolution seismic reflection profiles reveal the late Holocene sedimentation history. The seismic record shows a succession of five large lens-shaped seismic units (A to I), characterized by transparent/chaotic seismic facies with irregular lower boundaries, and interpreted as mass-movement deposits. These units are interbedded with parallel, continuous and strong amplitude reflections, interpreted as the 'background' lake sediments. The oldest dated mass movement (Unit D) covers a surface of 22 km2 in the deep basin, near the city of Lausanne. This deposit has an estimated minimum volume of 0.18 km3 and thus was very likely tsunamigenic (Kremer et al, 2012). A 12-m-long sediment core confirms the seismic interpretation of the mass movement unit and shows that the uppermost 3 m of Unit D are characterized by deformed hemipelagic sediments topped by a 5 cm thick turbidite. This deposit can be classified as a slump whose scar can be interpreted in the seismic data and visualized by multibeam bathymetry. This slump of Lausanne was likely triggered by an earthquake but a spontaneous slope collapse cannot be excluded (Girardclos et al, 2007). Radiocarbon dating of plant macro-remains reveals that the unit D happened during Early Bronze Age. Three other mass wasting deposits occurred during the same time period and may have been triggered during the same event, either by a single earthquake or by a tsunami generated by the slump of Lausanne. Although the exact trigger mechanism of the all these mass-wasting deposits remains unknown, a tsunami likely generated by this event may have affected the

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.

Use Of The Gpr To Characterize Sedimentary Structures Of Lakes In Sub-Humid Drainage System, Southeast Brazil

NASA Astrophysics Data System (ADS)

Aranha, P. A.; Augustin, C. H.

2012-12-01

PAULO ROBERTO ANTUNES ARANHA IGC - UNIVERSIDADE FEDERAL DE MINAS GERAIS - AV ANTONIO CARLOS 6.627 - CEP: 31270901-BELO HORIZONTE- MG - BRAZIL CRISTINA ROCHA AUGUSTIN - IGC - UNIVERSIDADE FEDERAL DE MINAS GERAIS - AV ANTONIO CARLOS 6.627 - CEP: 31270901-BELO HORIZONTE- MG - BRAZIL System of lakes located in the sandstones domains of Supergrupo Urucuia, in the State Park Veredas do Peruaçu, north of the State of Minas Gerais, Brazil, are common features in ecosystems of the Veredas, a biome of the Cerrado (Savanna-Open pasture). The linearity of these lakes suggests that they could have, in the past, belonged to the same drainage system, that would have been disconnected throughout the evolution of the Vereda system. The objective of this research is with the help of the GPR and using 100 MHz antennaes to obtain radargram images that could assist in the interpretation of the structures occurring at the bottom of these lakes. It is possible do identify on the radargrams reflectors that can be correlated with depositional system. These reflectore have the concave form. The results of these radargrames indicate great conformity between the concave form of the sediments and that of the bottom of the lake, allowing to assume that this deposition has been occurring since a long time ago. Therefore, if there was a connection between the study lake and those located in its proximity it has occurred a long time, before the deposition of the sedimentary sequences had been deposited. The thickness of the sediments, that varies since 2m until 5m, indicates that or either this deposition was either a very rapid one so that could generate a fast deposition, or it has been taking place during a considerable geologic long time.; Data acquisitiont;

Long-term records reveal decoupling of nitrogen and phosphorus cycles in a large, urban lake in response to an extreme rainfall event

NASA Astrophysics Data System (ADS)

Corman, J. R.; Loken, L. C.; Oliver, S. K.; Collins, S.; Butitta, V.; Stanley, E. H.

2017-12-01

Extreme events can play powerful roles in shifting ecosystem processes. In lakes, heavy rainfall can transport large amounts of particulates and dissolved nutrients into the water column and, potentially, alter biogeochemical cycling. However, the impacts of extreme rainfall events are often difficult to study due to a lack of long-term records. In this paper, we combine daily discharge records with long-term lake water quality information collected by the North Temperate Lakes Long-Term Ecological Research (NTL LTER) site to investigate the impacts of extreme events on nutrient cycling in lakes. We focus on Lake Mendota, an urban lake within the Yahara River Watershed in Madison, Wisconsin, USA, where nutrient data are available at least seasonally from 1995 - present. In June 2008, precipitation amounts in the Yahara watershed were 400% above normal values, triggering the largest discharge event on record for the 40 years of monitoring at the streamgage station; hence, we are able to compare water quality records before and after this event as a case study of how extreme rain events couple or decouple lake nutrient cycling. Following the extreme event, the lake-wide mass of nitrogen and phosphorus increased in the summer of 2008 by 35% and 21%, respectively, shifting lake stoichiometry by increasing N:P ratios (Figure 1). Nitrogen concentrations remained elevated longer than phosphorus, suggesting (1) that nitrogen inputs into the lake were sustained longer than phosphorus (i.e., a "smear" versus "pulse" loading of nitrogen versus phosphorus, respectively, in response to the extreme event) and/or (2) that in-lake biogeochemical processing was more efficient at removing phosphorus compared to nitrogen. While groundwater loading data are currently unavailable to test the former hypothesis, preliminary data from surficial nitrogen and phosphorus loading to Lake Mendota (available for 2011 - 2013) suggest that nitrogen removal efficiency is less than phosphorus

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

Drainage water phosphorus losses in the great lakes basin

USDA-ARS?s Scientific Manuscript database

The great lakes are one of the most important fresh water resources on the planet. While forestry is a primary land use throughout much of the great lakes basin, there are portions of the basin, such as much of the land that drains directly to Lake Erie, that are primarily agricultural. The primary ...

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...

Drainage divides, Massachusetts; Blackstone and Thames River basins

USGS Publications Warehouse

Krejmas, Bruce E.; Wandle, S. William

1982-01-01

Drainage boundaries for selected subbasins of the Blackstone and Thames River basins in eastern Hampden, eastern Hampshire, western Norfolk, southern Middlesex, and southern Worcester Counties, Massachusetts, are delineated on 12 topographic quadrangle maps at a scale of 1:24,000. Drainage basins are shown for all U.S. Geological Survey data-collection sites and for mouths of major rivers. Drainage basins are shown for the outlets of lakes or ponds and for streams where the drainage area is greater than 3 square miles. Successive sites along watercourses are indicated where the intervening area is at least 6 miles on tributary streams or 15 square miles along the Blackstone River, French River, or Quinebaug River. (USGS)

Influence of Acid Mine Drainage (AMD) on recent phyto- and zooplankton in "the Anthropogenic Lake District" in south-west Poland

NASA Astrophysics Data System (ADS)

Sienkiewicz, Elwira; Gasiorowski, Michal

2015-04-01

In south-west Poland (central Europe) many the post-mining lakes formed so-called "the Anthropogenic Lake District". Areas, where water comes in contact with lignite beds characterized by high concentration of sulfide minerals are called Acid Mine Drainage (AMD). Pyrite oxidation and other sulfide compounds caused release sulfuric acids and heavy metal ions. These processes caused decline of water pH, sometimes to extremely low pH < 2.8. Presently, pit lakes located in south-west Poland have water pH ranged between 2.7 and 8.9. Differences of water reaction in the mine lakes depend on many factors, such as bedrock buffer capacity, geological structure of carboniferous area, exploitation technique of lignite, methods of filling and water supply of reservoirs and their age. During the evolution of lakes' ecosystems, sulfate-iron-calcium type of waters occurring in acid lakes will transform in alkaline hydrogen-carbonate-calcium type of waters. Due to the different time of the completion of lignite exploitation, lakes' age varied between forty and over one hundred years. Studies showed that younger lakes are more acidic in compare to older. To estimate impact of AMD we analyzed recent diversity of diatoms and Cladocera remains and water chemistry from extremely acidic, relatively young lakes and from alkaline, older water bodies. As we expected, flora and fauna from acidic lakes have shown very low diversity and species richness. Among diatoms, Eunotia exigua (Bréb. ex Kütz.) Rabenhorst and/or E. paludosa Grunow were dominated taxa, while fauna Cladocera did not occurred in lakes with water pH < 3. On this area, exploitation of lignite continued up to 1973. Older lakes were formed in the region where the mine started work in 1880 and lignite mining stopped in 1926. Measurements of pH value in situ point to neutral or alkaline water, but because of the possibility of hysteresis phenomenon, the studies of phyto- and zooplankton have shown if there has already been a

Correlation of Late-Pleistocene Lake-Level Oscillations in Mono Lake, California, with North Atlantic Climate Events

USGS Publications Warehouse

Benson, L.V.; Lund, S.P.; Burdett, J.W.; Kashgarian, Michaele; Rose, T.P.; Smoot, J.P.; Schwartz, M.

1998-01-01

Oxygen-18 (18O) values of sediment from the Wilson Creek Formation, Mono Basin, California, indicate three scales of temporal variation (Dansgaard-Oeschger, Heinrich, and Milankovitch) in the hydrologic balance of Mono Lake between 35,400 and 12,900 14C yr B.P. During this interval, Mono Lake experienced four lowstands each lasting from 1000 to 2000 yr. The youngest low-stand, which occurred between 15,500 and 14,000 14C yr B.P., was nearly synchronous with a desiccation of Owens Lake, California. Paleomagnetic secular variation (PSV) data indicate that three of four persistent lowstands occurred at the same times as Heinrich events H1, H2, and H4. 18O data indicate the two highest lake levels occurred ???18,000 and ???13,100 14C yr B.P., corresponding to passages of the mean position of the polar jet stream over the Mono Basin. Extremely low values of total inorganic carbon between 26,000 and 14,000 14C yr B.P. indicate glacial activity, corresponding to a time when summer insolation was much reduced. ?? 1998 University of Washington.

Stable carbon and oxygen isotope record of central Lake Erie sediments

USGS Publications Warehouse

Tevesz, M.J.S.; Spongberg, A.L.; Fuller, J.A.

1998-01-01

Stable carbon and oxygen isotope data from mollusc aragonite extracted from sediment cores provide new information on the origin and history of sedimentation in the southwestern area of the central basin of Lake Erie. Sediments infilling the Sandusky subbasin consist of three lithologic units overlying glacial deposits. The lowest of these is a soft gray mud overlain by a shell hash layer containing Sphaerium striatinum fragments. A fluid mud unit caps the shell hash layer and extends upwards to the sediment-water interface. New stable isotope data suggest that the soft gray mud unit is of postglacial, rather than proglacial, origin. These data also suggest that the shell hash layer was derived from erosional winnowing of the underlying soft gray mud layer. This winnowing event may have occurred as a result of the Nipissing flood. The Pelee-Lorain moraine, which forms the eastern boundary of the Sandusky subbasin, is an elevated area of till capped by a sand deposit that originated as a beach. The presence of both the shell hash layer and relict beach deposit strengthens the interpretation that the Nipissing flood was a critical event in the development of the southwestern area of the central basin of Lake Erie. This event, which returned drainage from the upper lakes to the Lake Erie basin, was a dominant influence on regional stratigraphy, bathymetry, and depositional setting.

Influence of particulates on phosphorus loading exported from farm drainage during a storm event in the Everglades Agricultural Area

NASA Astrophysics Data System (ADS)

Bhadha, J. H.; Lang, T. A.; Daroub, S. H.

2015-12-01

The purpose of this study was to evaluate the influence of particulates on P loading captured during a single storm event. The Everglades Agricultural Area of Florida comprises 280,000 hectares of organic soil farmland artificially drained by ditches, canals and pumps. Phosphorus (P)-enriched suspended particulates in canals are susceptible to transport and can contribute significantly to the overall P loads in drainage water. A settling tank experiment was conducted to capture particulates during tropical storm Isaac in 2012 from three farms approximately 2.4 to 3.6 km2 in size. Farm canal discharge water was collected in a series of two 200 liter settling tanks over a seven-day drainage period, during tropical storm Isaac. Water from the settling tanks was siphoned through Imhoff settling cones, where the particulates were allowed to settle and collected for P-fractionation analyses, and compared to intact sediment cores collected from the bottom of the canals. The discharged particulates contained higher organic matter content (OM), total P, and labile P fractions compared to the canal bottom sediments. Based on the equilibrium P concentrations, surface sediments behave as a source of P to the water column. A seven-day continuous drainage event exported 4.7 to 11.1 metric tons of suspended solids per farm, corresponding to 32 to 63 kg of particulate P being lost to downstream ecosystems. Drainage associated to a single seven-day storm event exported up to 61% of the total annual farm P load. It is evident from this study that short-term, high-intensity storm events can skew annual P loads due to the export of significantly higher particulate matter from farm canals. Exported particulates rich in P can provide a supplemental source of nutrients if captured and replenished back into the farmlands, as a sustainable farming practice.

Effects of body size, condition, and lipid content on the survival of juvenile lake herring during rapid cooling events

USGS Publications Warehouse

Pangle, K.L.; Sutton, T.M.; Kinnunen, R.E.; Hoff, M.H.

2005-01-01

Juvenile lake herring Coregonus artedi were exposed to rapid cooling events during two laboratory experiments to determine the effects of body size, physiological condition, and lipid content on survival. The first experiment was conducted at the onset of winter, exposing small (50 to 85 mm) and large (85 to 129 mm) fish to a decline in water temperature from 12 to 2??C at a rate of 1??C/hr. During this experiment, both large and small individuals exposed to a rapid cooling event experienced no mortality or abnormal behaviors. Separate fish were then maintained under thermal and photoperiod regimes that mimicked those in Lake Superior from October through May. Fish in each size class were maintained at two feeding treatments: Artemia ad libitum and no food. At the completion of the winter period, these lake herring were subjected to the same rapid cooling event conducted in the first experiment. During the experiment, lake herring exhibited no mortality or abnormal behaviors despite treatment-dependent differences in condition and lipid content. Our results indicate that mortality due to rapid cooling events does not appear to contribute to the recruitment variability observed for juvenile lake herring in Lake Superior.

Joint Geodetic and Seismic Analysis of the effects of Englacial and Subglacial Hydraulics on Surface Crevassing near a Seasonal, Glacier-Dammed Lake on Gornergletscher, Switzerland

NASA Astrophysics Data System (ADS)

Garcia, L.; Luttrell, K. M.; Kilb, D. L.; Walter, F.

2017-12-01

Glacial outburst floods are difficult to predict and threaten human life and property near glaciated regions. These events are characterized by rapid draining of glacier-dammed lakes via the sub/englacial hydraulic network to the proglacial stream. The glacier-dammed lake on Gornergletscher in Switzerland, which fills and drains each summer, provides an opportunity to study this hazard. For three drainages (2004, 2006, and 2007), we track icequakes (IQ) and on-ice GPS movement. Our seasonal seismic networks had 8 - 24 three component stations and apertures of about 300 - 400 m on the glacier surface. The seasonal GPS arrays contained 4 - 8 GPS antennae on the glacier surface. Using Rayleigh wave coherence surface IQ location, we located 2924, 7822 and 3782 IQs, in 2004, 2006 and 2007, respectively. The GPS data were smoothed using a nonparametric protocol, with average station velocities of 10 - 90 mm/day. In 2006, strains were calculated using five stations within 500 m of the lake, co-located with the seismic network. IQ productivity increased substantially during lake drainage only in 2004, which was the only year when the lake drainage was rapid ( 6 days) and primarily subglacial. In 2006, there was no obvious increase in GPS speeds with slow ( 21 days), supraglacial lake drainage. However, when drainage was subglacial as in 2004 and 2007 (sub/englacial over 11 days), GPS speed increased up to 160%. This speed increase is evidence for basal sliding induced by subglacial drainage. In general, we find that when the strain increase on the principle extension axis aligns with the crevasse opening direction, IQ are more prolific. We also observe a diurnal signal in both IQ occurrence and surface strain, with peak strain occurring in the mid- to late-afternoon (15:00 - 19:00 local) across the study area in 2006. We interpret this time-shift in strain and spatiotemporal dependence of IQs to be caused by diurnal variations in melt-induced sliding. Our analysis sheds

Moisture sources of the Mono Lake deglacial pluvial events

NASA Astrophysics Data System (ADS)

Wang, X.; Liang, M. C.; Ali, G.; Shen, C. C.; Cai, Y.; Ke, L.; Hemming, S. R.

2016-12-01

Enormously expanded lakes existed in the today's dry western US Great Basin during the last glacial period. The ancient shorelines located well above modern lake levels suggest that precipitation in lake basins must have been substantially higher in the past. It is however under debate whether the subtropical North Pacific or the tropical Pacific is the major moisture source that contributed to the pluvial events, particularly during the deglaciation. Here, we collected a suite of tufa carbonate samples deposited at the 2,080 meter terrace ( 135 meters above today's lake level) in the Mono Basin, California, a closed lake basin for the last 130 thousand years (kyr). At Goat Ranch, we discovered white, shiny, laminated botryoidal carbonate coatings on tufa mounds. Most of these coatings present two generations of formation separated by a hiatus, which indicates lake level fluctuations. Using high-precision U-Th dating techniques, we found that the lower layer was formed 14.1-14.4 kyr BP (corresponding to the North Atlantic Bølling warming period). The upper layer of the coating was formed 11.9-12.3 kyr BP (within the Younger Dryas event). We then obtained d18O, d13C, D47 and 17O-excess values for the two carbonate layers. The upper part is characterized by low d18O values, -8 to -12 ‰ VPDB, whereas the lower one has higher d18O values, -5 to -6 ‰ VPDB. Both share similar d13C values ( 1-2‰ VPDB). D47 analysis on the carbonates suggests that both layers were deposited in a water temperature of 9±2 oC (1s, n = 4 and 8, respectively). The two generations of carbonates present 17O-excess of moisture in values of 50±5 (1s, n=4) and 25±5 (1s, n=8) per meg VSMOW-SLAP, respectively. The large difference in 17O-excess of parent meteoric water points to different origins of moisture for the tufa carbonate formations. The high 17O-excess values during YD suggest a moisture source with a low relative humidity, consistent with the conventional view that the moisture

The lowering of Glacial Lake Hitchcock in the Upper Connecticut Valley (New Hampshire and Vermont) as registered by varved sediments

NASA Astrophysics Data System (ADS)

Bigl, M.; Kelly, M. A.

2012-12-01

Subsequent to the last glacial maximum, the Laurentide Ice Sheet retreated northward through New England and New York and large glacial lakes formed in the Hudson, Connecticut and Merrimack Valleys. Varved sediments in these former lake basins preserve an incredible record of the timing and rates of ice sheet recession as well as regional climatic conditions. Here, we test the hypothesis that these varves also preserve a history of the lowering and drainage of the lakes. We present evidence of sudden increases in varve thicknesses within the former Glacial Lake Hitchcock (GLH) basin in the Connecticut River Valley of New Hampshire and Vermont and test the hypothesis that these result from lake-level lowering events. GLH existed in the Connecticut Valley due to a sediment dam at its southern end near Rocky Hill, CT. At its maximum, it may have extended from Rocky Hill to near Lyndon, VT. A breach of the Rocky Hill dam at ~13.5 ka caused the drainage of the southern basin of GLH, located south of the Holyoke Range in Massachusetts, but the northern basin of GLH (in the Upper Valley region of New Hampshire and Vermont) retained water until ~11.5 ka (Stone, 1999). However, no studies have focused on lake level fluctuation, exact timing of GLH drainage, and whether the lake drained in one episode or as a longer sequence of drainage events. We use sediment cores from modern lake basins to examine the lowering and final drainage of GLH in the Upper Valley region. As GLH lowered, these modern basins emerged (with higher elevation basins emerging first) and deposition in each basin transitioned from glacial varves to non-varved and organic-rich sediments. We hypothesize that during a lowering event a basin submerged by GLH would have received an increase in sediment flux from deposits exposed at the lakeshore and, thus, a sudden thickening of varves would occur. We test this hypothesis by comparing the age of the transition from glacial varves to non-varved and organic

Variety, State and Origin of Drained Thaw Lake Basins in West-Siberian North

NASA Astrophysics Data System (ADS)

Kirpotin, S.; Polishchuk, Y.; Bryksina, N.; Sugaipova, A.; Pokrovsky, O.; Shirokova, L.; Kouraev, A.; Zakharova, E.; Kolmakova, M.; Dupre, B.

2009-04-01

Drained thaw lake basins in Western Siberia have a local name "khasyreis" [1]. Khasyreis as well as lakes, ponds and frozen mounds are invariable element of sub-arctic frozen peat bogs - palsas and tundra landscapes. In some areas of West-Siberian sub-arctic khasyreis occupy up to 40-50% of total lake area. Sometimes their concentration is so high that we call such places ‘khasyrei's fields". Khasyreis are part of the natural cycle of palsa complex development [1], but their origin is not continuous and uniform in time and, according to our opinion, there were periods of more intensive lake drainage and khasyrei development accordingly. These times were corresponding with epochs of climatic warming and today we have faced with one of them. So, last years this process was sufficiently activated in the south part of West-Siberian sub-arctic [2]. It was discovered that in the zone of continuous permafrost thermokarst lakes have expanded their areas by about 10-12%, but in the zone of discontinuous permafrost the process of their drainage prevails. These features are connected with the thickness of peat layers which gradually decreases to the North, and thus have reduced the opportunity for lake drainage in northern areas. The most typical way of khasyrei origin is their drainage to the bigger lakes which are always situated on the lower levels and works as a collecting funnels providing drainage of smaller lakes. The lower level of the big lake appeared when the lake takes a critical mass of water enough for subsidence of the lake bottom due to the melting of underlaying rocks [2]. Another one way of lake drainage is the lake intercept by any river. Lake drainage to the subsurface (underlaying rocks) as some authors think [3, 4] is not possible in Western Siberia, because the thickness of permafrost is at list 500 m here being safe confining bed. We mark out few stages of khasyrei development: freshly drained, young, mature and old. This row reflects stages of

Annually laminated lake sediments as recorders of flood events: evidence from combining monitoring and calibration

NASA Astrophysics Data System (ADS)

Kämpf, Lucas; Brauer, Achim; Mueller, Philip; Güntner, Andreas; Merz, Bruno

2015-04-01

The relation of changing climate and the occurrence of strong flood events has been controversially debated over the last years. One major limitation in this respect is the temporal extension of instrumental flood time series, rarely exceeding 50-100 years, which is too short to reflect the full range of natural climate variability in a region. Therefore, geoarchives are increasingly explored as natural flood recorders far beyond the range of instrumental flood time series. Annually laminated (varved) lake sediments provide particularly valuable archives since (i) lakes form ideal traps in the landscape continuously recording sediment flux from the catchment and (ii) individual flood events are recorded as detrital layers and can be dated with seasonal precision by varve counting. Despite the great potential of varved lake sediments for reconstructing long flood time series, there are still some confinements with respect to their interpretation due to a lack in understanding processes controlling the formation of detrital layers. For this purpose, we investigated the formation of detrital flood layers in Lake Mondsee (Upper Austria) in great detail by monitoring flood-related sediment flux and comparing detrital layers in sub-recent sediments with river runoff data. Sediment flux at the lake bottom was trapped over a three-year period (2011-2013) at two locations in Lake Mondsee, one located 0.9 km off the main inflow (proximal) and one in a more distal position at a distance of 2.8 km. The monitoring data include 26 floods of different amplitude (max. hourly discharge=10-110 cbm/s) which triggered variable fluxes of catchment sediment to the lake floor (4-760 g/(sqm*d)). The comparison of runoff and sediment data revealed empiric runoff thresholds for triggering significant detrital sediment influx to the proximal (20 cbm/s) and distal lake basin (30 cbm/s) and an exponential relation between runoff amplitude and the amount of deposited sediment. A succession of

A long record of extreme wave events in coastal Lake Hamana, Japan

NASA Astrophysics Data System (ADS)

Boes, Evelien; Yokoyama, Yusuke; Schmidt, Sabine; Riedesel, Svenja; Fujiwara, Osamu; Nakamura, Atsunori; Garrett, Ed; Heyvaert, Vanessa; Brückner, Helmut; De Batist, Marc

2017-04-01

Coastal Lake Hamana is located near the convergent tectonic boundary of the Nankai-Suruga Trough, along which the Philippine Sea slab is subducted underneath the Eurasian Plate, giving rise to repeated tsunamigenic megathrust earthquakes (Mw ≥ 8). A good understanding of the earthquake- and tsunami-triggering mechanisms is crucial in order to better estimate the complexity of seismic risks. Thanks to its accommodation space, Lake Hamana may represent a good archive for past events, such as tsunamis and tropical storms (typhoons), also referred to as "extreme wave" events. Characteristic event layers, consisting of sediment entrained by these extreme waves and their backwash, are witnesses of past marine incursions. By applying a broad range of surveying methods (reflection-seismic profiling, gravity coring, piston coring), sedimentological analyses (CT-scanning, XRF-scanning, multi-sensor core logging, grain size, microfossils etc.) and dating techniques (210Pb/137Cs, 14C, OSL, tephrochronology), we attempt to trace extreme wave event deposits in a multiproxy approach. Seismic imagery shows a vertical stacking of stronger reflectors, interpreted to be coarser-grained sheets deposited by highly energetic waves. Systematic sampling of lake bottom sediments along a transect from ocean-proximal to ocean-distal sites enables us to evaluate vertical and lateral changes in stratigraphy. Ocean-proximal, we observe a sequence of eight sandy units separated by silty background sediments, up to a depth of 8 m into the lake bottom. These sand layers quickly thin out and become finer-grained land-inward. Seismic-to-core correlations show a good fit between the occurrence of strong reflectors and sandy deposits, hence confirming presumptions based on acoustic imagery alone. Sand-rich intervals typically display a higher magnetic susceptibility, density and stronger X-ray attenuation. However, based on textural and structural differences, we can make the distinction between

Features of lava lake filling and draining and their implications for eruption dynamics

USGS Publications Warehouse

Stovall, W.K.; Houghton, Bruce F.; Harris, A.J.L.; Swanson, D.A.

2009-01-01

Lava lakes experience filling, circulation, and often drainage depending upon the style of activity and location of the vent. Features formed by these processes have proved difficult to document due to dangerous conditions during the eruption, inaccessibility, and destruction of features during lake drainage. Kilauea Iki lava lake, Kilauea, Hawai'i, preserves many such features, because lava ponded in a pre-existing crater adjacent to the vent and eventually filled to the level of, and interacted with, the vent and lava fountains. During repeated episodes, a cyclic pattern of lake filling to above vent level, followed by draining back to vent level, preserved features associated with both filling and draining. Field investigations permit us to describe the characteristic features associated with lava lakes on length scales ranging from centimeters to hundreds of meters in a fashion analogous to descriptions of lava flows. Multiple vertical rinds of lava coating the lake walls formed during filling as the lake deepened and lava solidified against vertical faces. Drainage of the lake resulted in uneven formation of roughly horizontal lava shelves on the lakeward edge of the vertical rinds; the shelves correlate with stable, staggered lake stands. Shelves either formed as broken relict slabs of lake crust that solidified in contact with the wall or by accumulation, accretion, and widening at the lake surface in a dynamic lateral flow regime. Thin, upper lava shelves reflect an initially dynamic environment, in which rapid lake lowering was replaced by slower and more staggered drainage with the formation of thicker, more laterally continuous shelves. At all lava lakes experiencing stages of filling and draining these processes may occur and result in the formation of similar sets of features. ?? Springer-Verlag 2009.

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.

Using satellite images to monitor glacial-lake outburst floods: Lago Cachet Dos drainage, Chile

USGS Publications Warehouse

Friesen, Beverly A.; Cole, Christopher J.; Nimick, David A.; Wilson, Earl M.; Fahey, Mark J.; McGrath, Daniel J.; Leidich, Jonathan

2015-01-01

During 2008–2013, 14 GLOFs were released from Lago Cachet Dos and created environmental and safety concerns for downstream residents and to infrastructure. If GLOFs and the consequent headward erosion continue, the moraine that creates Lago Cachet Uno could be destabilized and breached, and the two lakes could merge. If the two lakes become connected, the volume of future GLOFs likely would be greater and thus cause longer and (or) more extensive flooding downstream. Additional GLOFs from Lago Cachet Dos are expected in the future, and continued environmental monitoring could provide an early warning system as well as scientific information that could increase our understanding of GLOFs and their consequences. GLOFs occur in glaciated areas around the world and remote sensing technologies can allow researchers to better understand—and potentially predict—future GLOF events.

ERTS: A multispectral image analysis contribution for the geomorphological evaluation of southern Maracaibo Lake Basin. [geological survey and drainage patterns

NASA Technical Reports Server (NTRS)

Salas, F.; Cabello, O.; Alarcon, F.; Ferrer, C.

1974-01-01

Multispectral analysis of ERTS-A images at scales of 1:1,000,000 and 1:500,000 has been conducted with conventional photointerpretation methods. Specific methods have been developed for the geomorphological analysis of southern Maracaibo Lake Basin which comprises part of the Venezuelan Andean Range, Perija Range, the Tachira gap and the Southern part of the Maracaibo Lake depression. A steplike analysis was conducted to separate macroforms, landscapes and relief units as well as drainage patterns and tectonic features, which permitted the delineation of tectonic provinces, stratigraphic units, geomorphologic units and geomorphologic positions. The geomorphologic synthesis obtained compares favorably with conventional analysis made on this area for accuracy of 1:100,000 scale, and in some features with details obtained through conventional analysis for accuracy of 1:15,000 and field work. Geomorphological units in the mountains were identified according to changes in tone, texture, forms orientation of interfluves and tectonic characteristics which control interfluvial disimetrics.

Mid-latitude Ozone Depletion Events Caused by Halogens from the Great Salt Lake in Utah

NASA Astrophysics Data System (ADS)

Fibiger, D. L.; Goldberger, L.; Womack, C.; McDuffie, E. E.; Dube, W. P.; Franchin, A.; Middlebrook, A. M.; Thornton, J. A.; Brown, S. S.

2017-12-01

Halogens are highly reactive chemicals and play an important role in atmospheric chemistry. They can be involved in many cycles which influence the oxidizing capacity of the atmosphere, including through destruction of ozone (O3). While the influence of halogens on O3 is well documented in the arctic, there are very few observations of O3 depletion driven by halogens in the mid-latitudes. To date, the most comprehensive study observed co-occurring plumes of BrO and depleted O3 near the Dead Sea in 1997. During the Utah Wintertime Fine Particulate Study (UWFPS) in winter 2017, simultaneous measurements of a comprehensive suite of halogen measurements by I- chemical ionization mass spectrometry and O3 from cavity ring-down spectroscopy, both at 1-second time resolution, were taken on a NOAA Twin Otter Aircraft over the Great Salt Lake and in the surrounding valleys. Many O3 depletion events were observed over the lake with O3 values sometimes below the instrument detection limit of 0.5 ppbv. Corresponding increases in BrO and/or ClO were observed. Many of these events were caused by extremely high levels of halogens (up to 1 ppmv Cl2) emitted from the U.S. Magnesium plant on the edge of the lake. The O3 depletion caused by U.S. Magnesium was usually isolated to a distinct vertical layer, but in other cases O3 depletion was vertically mixed and the origin of halogen activation was not immediately clear. The most complete O3 depletion was observed over the lake, but there were smaller events of a few ppbv observed in the adjacent valleys, including the highly populated Salt Lake Valley, with corresponding plumes of BrO and ClO, due to transport from the lake. Additionally, meteorology played a role in the observed O3 depletion. The strongest O3 depletion was observed during inversion events, when there is a low boundary layer and little mixing out of the air above the lake. During non-inversion conditions, only small depletions were observed, covering a much smaller

Discontinuities in stream nutrient uptake below lakes in mountain drainage networks

USGS Publications Warehouse

Arp, C.D.; Baker, M.A.

2007-01-01

In many watersheds, lakes and streams are hydrologically linked in spatial patterns that influence material transport and retention. We hypothesized that lakes affect stream nutrient cycling via modifications to stream hydrogeomorphology, source-waters, and biological communities. We tested this hypothesis in a lake district of the Sawtooth Mountains, Idaho. Uptake of NO3- and PO4-3 was compared among 25 reaches representing the following landscape positions: lake inlets and outlets, reaches >1-km downstream from lakes, and reference reaches with no nearby lakes. We quantified landscape-scale hydrographic and reach-scale hydrogeomorphic, source-water, and biological variables to characterize these landscape positions and analyze relationships to nutrient uptake. Nitrate uptake was undetectable at most lake outlets, whereas PO4-3 uptake was higher at outlets as compared to reference and lake inlet reaches. Patterns in nutrient demand farther downstream were similar to lake outlets with a gradual shift toward reference-reach functionality. Nitrate uptake was most correlated to sediment mobility and channel morphology, whereas PO 4-3 uptake was most correlated to source-water characteristics. The best integrated predictor of these patterns in nutrient demand was % contributing area (the proportion of watershed area not routing through a lake). We estimate that NO3- and PO 4-3 demand returned to 50% of pre-lake conditions within 1-4-km downstream of a small headwater lake and resetting of nutrient demand was slower downstream of a larger lake set lower in a watershed. Full resetting of these nutrient cycling processes was not reached within 20-km downstream, indicating that lakes can alter stream ecosystem functioning at large spatial scales throughout mountain watersheds. ?? 2007, by the American Society of Limnology and Oceanography, Inc.

Drainage-basis-scale geomorphic analysis to determine refernce conditions for ecologic restoration-Kissimmee River, Florida

USGS Publications Warehouse

Warne, A.G.; Toth, L.A.; White, W.A.

2000-01-01

Major controls on the retention, distribution, and discharge of surface water in the historic (precanal) Kissimmee drainage basin and river were investigated to determine reference conditions for ecosystem restoration. Precanal Kissimmee drainage-basin hydrology was largely controlled by landforms derived from relict, coastal ridge, lagoon, and shallow-shelf features; widespread carbonate solution depressions; and a poorly developed fluvial drainage network. Prior to channelization for flood control, the Kissimmee River was a very low gradient, moderately meandering river that flowed from Lake Kissimmee to Lake Okeechobee through the lower drainage basin. We infer that during normal wet seasons, river discharge rapidly exceeded Lake Okeechobee outflow capacity, and excess surface water backed up into the low-gradient Kissimmee River. This backwater effect induced bankfull and peak discharge early in the flood cycle and transformed the flood plain into a shallow aquatic system with both lacustrine and riverine characteristics. The large volumes of surface water retained in the lakes and wetlands of the upper basin maintained overbank flow conditions for several months after peak discharge. Analysis indicates that most of the geomorphic work on the channel and flood plain occurred during the frequently recurring extended periods of overbank discharge and that discharge volume may have been significant in determining channel dimensions. Comparison of hydrogeomorphic relationships with other river systems identified links between geomorphology and hydrology of the precanal Kissimmee River. However, drainage-basin and hydraulic geometry models derived solely from general populations of river systems may produce spurious reference conditions for restoration design criteria.

The effect of drainage reorganization on paleoaltimetry studies: An example from the Paleogene Laramide foreland

NASA Astrophysics Data System (ADS)

Davis, Steven J.; Wiegand, Bettina A.; Carroll, Alan R.; Chamberlain, C. Page

2008-11-01

Using multiple isotope systems, we examine the complex effects of drainage reorganization in the Laramide Foreland in the context of stable isotope paleoaltimetry. Strontium, oxygen and carbon isotopic data from lacustrine carbonates formed in the southwestern Uinta Basin, Utah between the Late Cretaceous and late Middle Eocene reveal a two stage expansion in the drainage basin of Lake Uinta beginning at ~ 53 Ma culminating in the Mahogany highstand at 48.6 Ma. A marked increase in 87Sr/ 86Sr ratios of samples from the Main Body of the Green River Formation is interpreted as the result of water overflowing the Greater Green River Basin in Wyoming and entering Lake Uinta from the east via the Piceance Creek Basin of northwestern Colorado. This large new source of water caused a rapid expansion of Lake Uinta and was accompanied by a significant and rapid increase in the O isotope record of carbonate samples by ~ 6‰. The periodic overspilling of Lake Gosiute probably became continuous at ~ 49 Ma, when the lake captured low- δ18O water from the Challis and Absaroka Volcanic Fields to the north. However, evaporation in the Greater Green River and Piceance Creek Basins meant that the waters entering Lake Uinta were still enriched in 18O. By ~ 46 Ma, inflows from the Greater Green River Basin ceased, resulting in a lowstand of Lake Uinta and the deposition of bedded evaporites in the Saline Facies of the Green River Formation. We thus show that basin development and lake hydrology in the Laramide foreland were characterized by large-scale changes in Cordilleran drainage patterns, capable of confounding paleoaltimetry studies premised on too few isotopic systems, samples or localities. In the case of the North American Cordillera of the Paleogene, we further demonstrate the likelihood that (1) topographic evolution of distal source areas strongly influenced the isotopic records of intraforeland basins and (2) a pattern of drainage integration between the hinterland and

Water-quality and lake-stage data for Wisconsin lakes, water year 1996

USGS Publications Warehouse

,

1997-01-01

The purpose of this report is to provide information about the physical and chemical characteristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected includes measurements of lake stage and in-lake water quality. Graphs of Secchi depths, surface totalphosphorus and chlorophyll-a concentrations versus time are included for lakes with two or more years of data. Graphs of vertical profiles of temperature, dissolved oxygen, pH, and specific conductance are included for sites where these parameters were measured. Descriptive information for each lake includes: location of the lake, drainage area of the lake's watershed, period for which data are available, revisions to previously published records, and pertinent remarks. Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes, are published in another volume: "Water Resources Data-Wisconsin, 1996."

Detection and Modeling of a Meteotsunami in Lake Erie During a High Wind Event on May 27, 2012

NASA Astrophysics Data System (ADS)

Anderson, E. J.; Schwab, D. J.; Lombardy, K. A.; LaPlante, R. E.

2012-12-01

On May 27, 2012, a mesoscale convective system moved southeast across the central basin of Lake Erie (the shallowest of the Great Lakes) causing an increase in surface wind speed from 3 to 15 m/s over a few minutes. Although no significant pressure change was observed during this period (+1 mbar), the storm resulted in 3 reported edge waves on the southern shore (5 minutes apart), with wave heights up to 7 feet (2.13 m). Witnesses along the coast reported that the water receded before the waves hit, the only warning of the impending danger. After impact on the southern shore, several individuals were stranded in the water near Cleveland, Ohio. Fortunately, there were no fatalities or serious injury as a result of the edge waves. The storm event yielded two separate but similar squall line events that impacted the southern shore of Lake Erie several hours apart. The first event had little impact on nearshore conditions, however, the second event (moving south-eastward at 21.1 m/s or 41 knots), resulted in 7 ft waves near Cleveland as reported above. The thunderstorms generated three closely packed outflow boundaries that intersected the southern shore of Lake Erie between 1700 and 1730 UTC. The outflow boundaries were followed by a stronger outflow at 1800 UTC. Radial velocities on the WSR-88D in Cleveland, Ohio indicated the winds were stronger in the second outflow boundary. The radar indicated winds between 20.6 and 24.7 m/s (40 and 48 knots) within 240 meters (800 feet) above ground level. In order to better understand the storm event and the cause of the waves that impacted the southern shore, a three-dimensional hydrodynamic model of Lake Erie has been developed using the Finite Volume Coastal Ocean Model (FVCOM). The model is being developed as part of the Great Lakes Coastal Forecasting (GLCFS), a set of experimental real-time pre-operational hydrodynamic models run at the NOAA Great Lakes Research Laboratory that forecast currents, waves, temperature, and

Drainage basin control of acid loadings to two Adirondack lakes

NASA Astrophysics Data System (ADS)

Booty, W. G.; Depinto, J. V.; Scheffe, R. D.

1988-07-01

Two adjacent Adirondack Park (New York) calibrated watersheds (Woods Lake and Cranberry Pond), which receive identical atmospheric inputs, generate significantly different unit area of watershed loading rates of acidity to their respective lakes. A watershed acidification model is used to evaluate the watershed parameters which are responsible for the observed differences in acid loadings to the lakes. The greater overall mean depth of overburden on Woods Lake watershed, which supplies a greater buffer capacity as well as a longer retention time of groundwater, appears to be the major factor responsible for the differences.

Protocol of a prospective cohort study of the effect of different methods of drainage of neuropathic bladder on occurrence of symptomatic urinary infection, and adverse events related to the urinary drainage system in spinal cord injury patients

PubMed Central

Vaidyanathan, Subramanian; Soni, Bhakul M; Gurpreet, Singh; Mansour, Paul; Hughes, Peter L; Oo, Tun; Sett, Pradipkumar; Parsons, Keith F; Davies, John C

2001-01-01

Background To present a protocol of a prospective, cohort study in which four groups of spinal cord injury (SCI) patients will participate. (Patients with indwelling urethral catheter; patients who perform intermittent catheterisation without wearing a penile sheath; patients who perform intermittent catheterisation and wear penile sheath as well; and patients with penile sheath drainage). Objectives (1) What is the incidence of symptomatic urinary infection in men with spinal cord injury who use different types of bladder drainage? (2) Which are predisposing factors for the occurrence of symptomatic urinary infection in men with spinal cord injury who practise different methods of bladder drainage? (3) What is the incidence of catheter and urinary drainage system-related adverse events in the four groups of SCI patients? Patients The criteria for inclusion are as follow: (1) Male patients with neuropathic bladder due to spinal cord injury, who are registered with the Regional Spinal Injuries Centre, Southport, England. (2) Age: 18 years or above. (3) Patients who are willing to give informed consent for participation in the study. (4) Patients willing to be contacted every two weeks by a staff of the spinal unit for 36 months. (5) Patients who are willing to maintain an accurate record of adverse events related to urinary catheter and urinary drainage system and predisposing factors for the occurrence of symptomatic urinary infection. (6) Patients, who are stabilised in a particular method of bladder drainage, and therefore, unlikely to make a permanent change in the method of bladder drainage (e.g. from penile sheath drainage to the use of long-term indwelling catheter) during a foreseeable future. Methods The participants will be observed for a period of 36 months. A staff of the spinal injuries unit will contact the participants by telephone every two weeks on a mutually agreed day and time. The information obtained during this standardised telephonic interview

Dune-dammed lakes of the Nebraska Sand Hills: Geologic setting and paleoclimatic implications

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

Loope, D.B.; Swinehart, J.B.

1992-01-01

Within the western half of this grass-stabilized dunefield, about 1,000 interdune lakes are grouped into two clusters here named the Blue and Birdwood lake basins. In the lake basins, those parts of the valley not filled by dune sand are occupied by modern lakes and Holocene lake sediments. The Blue Creek dam is mounded transverse to flow; spill-over of the lake basin takes place over bedrock on the east side of the dam when lake level is 2 m higher than present. The permeability of dune sand prevents massive overflow, and thereby contributes to the integrity and longevity of themore » dam. Preserved lake sediments in the basin indicate that Blue Creek was obstructed prior to 13,000 yr BP, probably during glacial maximum (18,000 yr BP). Extensive peats dated at 1,500-1,000 yr BP lie directly on fluvial sand and gravel along the Calamus River, a stream that presently discharges a nearly constant 350 cfs. These sediments indicate blockage of streams also took place when linear dunes were active in the eastern Sand Hills in Late Holocene time. With the onset of an arid episode, dunes forming an interfluves curtail the severity of runoff events. As the regional water table drops, drainages go dry and dunes move uncontested into blocking positions. Although drainages of the eastern Sand Hills appear to have repeatedly broken through sand-blocked channels, the Blue and Birdwood lake basins are still blocked by Late Pleistocene dune dams. The repeated episodes of stream blockage and interbedded lake sediments and dune sands behind the extant dams record several strong fluctuations in Holocene climate. Recently proposed climatic models indicate that the northward flow of warm, moist air from the Gulf of Mexico is enhanced when the Gulf's surface temperature is low and the Bermuda high is intensified and in a western position. When the Bermuda high moves eastward, the core of the North American continent becomes desiccated.« less

The rise and fall of Lake Bonneville between 45 and 10.5 ka

USGS Publications Warehouse

Benson, L.V.; Lund, S.P.; Smoot, J.P.; Rhode, D.E.; Spencer, R.J.; Verosub, K.L.; Louderback, L.A.; Johnson, C.A.; Rye, R.O.; Negrini, R.M.

2011-01-01

A sediment core taken from the western edge of the Bonneville Basin has provided high-resolution proxy records of relative lake-size change for the period 45.1-10.5 calendar ka (hereafter ka). Age control was provided by a paleomagnetic secular variation (PSV)-based age model for Blue Lake core BL04-4. Continuous records of ??18O and total inorganic carbon (TIC) generally match an earlier lake-level envelope based on outcrops and geomorphic features, but with differences in the timing of some hydrologic events/states. The Stansbury Oscillation was found to consist of two oscillations centered on 25 and 24 ka. Lake Bonneville appears to have reached its geomorphic highstand and began spilling at 18.5 ka. The fall from the highstand to the Provo level occurred at 17.0 ka and the lake intermittently overflowed at the Provo level until 15.2 ka, at which time the lake fell again, bottoming out at ~14.7 ka. The lake also fell briefly below the Provo level at ~15.9 ka. Carbonate and ??18O data indicate that between 14.7 and 13.1 ka the lake slowly rose to the Gilbert shoreline and remained at about that elevation until 11.6 ka, when it fell again. Chemical and sedimentological data indicate that a marsh formed in the Blue Lake area at 10.5 ka.Relatively dry periods in the BL04-4 records are associated with Heinrich events H1-H4, suggesting that either the warming that closely followed a Heinrich event increased the evaporation rate in the Bonneville Basin and (or) that the core of the polar jet stream (PJS) shifted north of the Bonneville Basin in response to massive losses of ice from the Laurentide Ice Sheet (LIS) during the Heinrich event. The second Stansbury Oscillation occurred during Heinrich event H2, and the Gilbert wet event occurred during the Younger Dryas cold interval. Several relatively wet events in BL04-4 occur during Dansgaard-Oeschger (DO) warm events.The growth of the Bear River glacier between 32 and 17 ka paralleled changes in the values of proxy

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

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.

Extent of Pleistocene lakes in the western Great Basin

USGS Publications Warehouse

Reheis, Marith C.

1999-01-01

During the Pliocene to middle Pleistocene, pluvial lakes in the western Great Basin repeatedly rose to levels much higher than those of the well-documented late Pleistocene pluvial lakes, and some presently isolated basins were connected. Sedimentologic, geomorphic, and chronologic evidence at sites shown on the map indicates that Lakes Lahontan and Columbus-Rennie were as much as 70 m higher in the early-middle Pleistocene than during their late Pleistocene high stands. Lake Lahontan at its 1400-m shoreline level would submerge present-day Reno, Carson City, and Battle Mountain, and would flood other now-dry basins. To the east, Lakes Jonathan (new name), Diamond, Newark, and Hubbs also reached high stands during the early-middle(?) Pleistocene that were 25-40 m above their late Pleistocene shorelines; at these very high levels, the lakes became temporarily or permanently tributary to the Humboldt River and hence to Lake Lahontan. Such a temporary connection could have permitted fish to migrate from the Humboldt River southward into the presently isolated Newark Valley and from Lake Lahontan into Fairview Valley. The timing of drainage integration also provides suggested maximum ages for fish to populate the basins of Lake Diamond and Lake Jonathan. Reconstructing and dating these lake levels also has important implications for paleoclimate, tectonics, and drainage evolution in the western Great Basin. For example, shorelines in several basins form a stair-step sequence downward with time from the highest levels, thought to have formed at about 650 ka, to the lowest, formed during the late Pleistocene. This descending sequence indicates progressive drying of pluvial periods, possibly caused by uplift of the Sierra Nevada and other western ranges relative to the western Great Basin. However, these effects cannot account for the extremely high lake levels during the early middle Pleistocene; rather, these high levels were probably due to a combination of increased

Comparison of Irrigation Water Use Estimates Calculated from Remotely Sensed Irrigated Acres and State Reported Irrigated Acres in the Lake Altus Drainage Basin, Oklahoma and Texas, 2000 Growing Season

USGS Publications Warehouse

Masoner, J.R.; Mladinich, C.S.; Konduris, A.M.; Smith, S. Jerrod

2003-01-01

Increased demand for water in the Lake Altus drainage basin requires more accurate estimates of water use for irrigation. The U.S. Geological Survey, in cooperation with the U.S. Bureau of Reclamation, is investigating new techniques to improve water-use estimates for irrigation purposes in the Lake Altus drainage basin. Empirical estimates of reference evapotranspiration, crop evapotranspiration, and crop irrigation water requirements for nine major crops were calculated from September 1999 to October 2000 using a solar radiation-based evapotranspiration model. Estimates of irrigation water use were calculated using remotely sensed irrigated crop acres derived from Landsat 7 Enhanced Thematic Mapper Plus imagery and were compared with irrigation water-use estimates calculated from irrigated crop acres reported by the Oklahoma Water Resources Board and the Texas Water Development Board for the 2000 growing season. The techniques presented will help manage water resources in the Lake Altus drainage basin and may be transferable to other areas with similar water management needs. Irrigation water use calculated from the remotely sensed irrigated acres was estimated at 154,920 acre-feet; whereas, irrigation water use calculated from state reported irrigated crop acres was 196,026 acre-feet, a 23 percent difference. The greatest difference in irrigation water use was in Carson County, Texas. Irrigation water use for Carson County, Texas, calculated from the remotely sensed irrigated acres was 58,555 acrefeet; whereas, irrigation water use calculated from state reported irrigated acres was 138,180 acre-feet, an 81 percent difference. The second greatest difference in irrigation water use occurred in Beckham County, Oklahoma. Differences between the two irrigation water use estimates are due to the differences of irrigated crop acres derived from the mapping process and those reported by the Oklahoma Water Resources Board and Texas Water Development Board.

77 FR 37807 - Regattas and Marine Parades; Great Lakes Annual Marine Events

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-25

... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 100 [Docket No. USCG-2012-0572] Regattas and Marine Parades; Great Lakes Annual Marine Events AGENCY: Coast Guard, DHS. ACTION: Notice of enforcement of regulation. SUMMARY: The Coast Guard will enforce various special local regulations for annual...

75 FR 26091 - Regattas and Marine Parades; Great Lakes Annual Marine Events

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-11

... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 100 [Docket No. USCG-2010-0312] Regattas and Marine Parades; Great Lakes Annual Marine Events AGENCY: Coast Guard, DHS. ACTION: Notice of enforcement of regulation. SUMMARY: The Coast Guard will enforce the local regulations for annual regattas and...

Characterization of turbidity in Florida's Lake Okeechobee and Caloosahatchee and St. Lucie estuaries using MODIS-Aqua measurements.

PubMed

Wang, Menghua; Nim, Carl J; Son, Seunghyun; Shi, Wei

2012-10-15

This paper describes the use of ocean color remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite to characterize turbidity in Lake Okeechobee and its primary drainage basins, the Caloosahatchee and St. Lucie estuaries from 2002 to 2010. Drainage modification and agricultural development in southern Florida transport sediments and nutrients from watershed agricultural areas to Lake Okeechobee. As a result of development around Lake Okeechobee and the estuaries that are connected to Lake Okeechobee, estuarine conditions have also been adversely impacted, resulting in salinity and nutrient fluctuations. The measurement of water turbidity in lacustrine and estuarine ecosystems allows researchers to understand important factors such as light limitation and the potential release of nutrients from re-suspended sediments. Based on a strong correlation between water turbidity and normalized water-leaving radiance at the near-infrared (NIR) band (nL(w)(869)), a new satellite water turbidity algorithm has been developed for Lake Okeechobee. This study has shown important applications with satellite-measured nL(w)(869) data for water quality monitoring and measurements for turbid inland lakes. MODIS-Aqua-measured water property data are derived using the shortwave infrared (SWIR)-based atmospheric correction algorithm in order to remotely obtain synoptic turbidity data in Lake Okeechobee and normalized water-leaving radiance using the red band (nL(w)(645)) in the Caloosahatchee and St. Lucie estuaries. We found varied, but distinct seasonal, spatial, and event driven turbidity trends in Lake Okeechobee and the Caloosahatchee and St. Lucie estuary regions. Wind waves and hurricanes have the largest influence on turbidity trends in Lake Okeechobee, while tides, currents, wind waves, and hurricanes influence the Caloosahatchee and St. Lucie estuarine areas. Published by Elsevier Ltd.

Insights from analyzing and modelling cascading multi-lake outburst flood events in the Santa Cruz Valley (Cordillera Blanca, Perú)

NASA Astrophysics Data System (ADS)

Emmer, Adam; Mergili, Martin; Juřicová, Anna; Cochachin, Alejo; Huggel, Christian

2016-04-01

Since the end of Little Ice Age, the Cordillera Blanca of Perú has experienced tens of lake outburst floods (LOFs), resulting in the loss of thousands of lives and significant material damages. Most commonly involving glacial lakes, such events are often directly or indirectly related to glacier retreat. Here we analyze an event on 8th February 2012 involving four lakes and affecting two valleys (Santa Cruz and Artizón) in the northern part of the Cordillera Blanca. Using the combination of field data, satellite images, digital elevation model (DEM) and GIS-based modelling approaches, the main objectives are: (i) to better understand complex multi-lake outburst flood and related foregoing and induced geomorphological processes; and (ii) to evaluate and discuss the suitability, potentials and limitations of the r.avaflow model for modelling such complex process chains. Analyzing field geomorphological evidence and remotely-sensed images, we reconstruct the event as follows: a landslide from the recently deglaciated left lateral moraine of Lake Artizón Alto (4 639 m a.s.l.), characterized by steep slopes and a height of more than 200 m produced a displacement wave which overtopped the bedrock dam of the lake. The resulting flood wave breached the dam of the downstream moraine-/landslide-dammed Lake Artizón Bajo (4 477 m a.s.l.), decreasing the lake level by 10 m and releasing 3 x 105 m3 of water. Significant amounts of material were eroded from the steeper parts of the Artizón Valley (mean slope >15°) and deposited further downstream in the flatter part of the Santa Cruz Valley (mean slope <2°; confluence of the two valleys at 3 985 m a.s.l.). The flood affected two debris cone-dammed lakes (Jatuncocha and Ichiccocha) in the Santa Cruz Valley. Some minor damages to the dam of Lake Jatuncocha were documented. Geomprohological evidence of the event was observed more than 20 km downstream from Lake Artizón Alto. The described multi-LOF event was employed as a

An iron-age cultural hiatus enigma: mega-flooding and human settlement abandonment over the last millennium in the Lanyang Drainage System, northeastern Taiwan

NASA Astrophysics Data System (ADS)

Huang, Jyh-Jaan; Wei, Kuo-Yen; Löwemark, Ludvig; Song, Sheng-Rong; Huh, Chih-An; Chuang, Chih-Kai; Yang, Tien-Nan; Lee, Meng-Yang; Chen, Yu-Be; Lee, Teh-Quei

2015-04-01

Active tectonic activities and frequent typhoon landfalls make Taiwan unique in having very high rates of uplift, precipitation, denudation and sedimentation. Particularly, intense rainfall associated with typhoons often causes flooding, large-scale landslides, and debris flows in river systems. Such natural disasters have affected human societies both at present and in the past; the Typhoon Morakot in 2009 may serve as a modern example of such events. Kiwulan is a newly discovered archaeological site from the Iron Age situated on the Lanyang Plain in NE Taiwan. In the deposits from this society, a cultural hiatus centered around 1200-1500 cal. yr AD is found, suggesting that the settlement was abandoned for a period of a few hundred years before being recolonized. Until now it has remained a mystery what caused this cultural hiatus. This study assembles radiocarbon dates of upland river terraces, organic proxies in flood plain lake sediments, and content of wood shreds in nearby marine sediments from the continental slope off NE Taiwan. These records are synthesized to infer the frequency and magnitude of ancient flood events over the past 1250 years in the Lanyang Drainage System in northeastern Taiwan. Alluvial fan terraces distributed along the banks of the upper Lanyang River are considered to be the results of ancient debris flow events, and their radiocarbon dates fall in two time ranges: 850-1100 and 1400-1600 cal. yr AD. Organic proxies which representing terrestrial organic input were measured from bulk sediments of Lake Dahu and Lake Meihua in the Lanyang Plain. Peak values of TOC, C/N ratio and organic indicator (inc/coh) from Itrax-XRF core scanner measurements are conspicuous during 900-950, and 1400-1500 cal. yr AD, implying frequent flood events. Moreover, abundance peaks of wood shreds and peaks in the C/N ratio in marine box core ORI-801-7A from the continental slope SE of the Lanyang Plain are dated to about 950-1050 and 1450-1550 cal. yr AD

Meltwater drainage beneath ice sheets: What can we learn from uniting observations of paleo- and contemporary subglacial hydrology?

NASA Astrophysics Data System (ADS)

Simkins, L. M.; Carter, S. P.; Greenwood, S. L.; Schroeder, D. M.

2017-12-01

Understanding meltwater at the base of ice sheets is critical for predicting ice flow and subglacial sediment deformation. Whereas much progress has been made with observing contemporary systems, these efforts have been limited by the short temporal scales of remote sensing data, the restricted spatial coverage of radar sounding data, and the logistical challenges of direct access. Geophysical and sedimentological data from deglaciated continental shelves reveal broad spatial and temporal perspectives of subglacial hydrology, that complement observations of contemporary systems. Massive bedrock channels, such as those on the sediment-scoured inner continental shelf of the Amundsen Sea and the western Antarctic Peninsula, are up to hundreds of meters deep, which indicate either catastrophic drainage events or slower channel incision over numerous glaciations or sub-bank full drainage events. The presence of these deep channels has implications for further ice loss as they may provide conduits today for warm water incursion into sub-ice shelf cavities. Sediment-based subglacial channels, widespread in the northern hemisphere terrestrial domain and increasingly detected on both Arctic and Antarctic marine margins, help characterize more ephemeral drainage systems active during ice sheet retreat. Importantly, some observed sediment-based channels are connected to upstream subglacial lakes and terminate at paleo-grounding lines. From these records of paleo-subglacial hydrology, we extract the relative timing of meltwater drainage, estimate water fluxes, and contemplate the sources and ultimate fate of basal meltwater, refining predictive models for modern systems. These insights provided by geological data fill a gap in knowledge regarding spatial and temporal dynamics of subglacial hydrology and offer hindsight into meltwater drainage influence/association with ice flow and retreat behavior. The union of information gathered from paleo- and contemporary subglacial

Geochemical evolution of Great Salt Lake, Utah, USA

USGS Publications Warehouse

Jones, B.F.; Naftz, D.L.; Spencer, R.J.; Oviatt, Charles G.

2009-01-01

The Great Salt Lake (GSL) of Utah, USA, is the largest saline lake in North America, and its brines are some of the most concentrated anywhere in the world. The lake occupies a closed basin system whose chemistry reflects solute inputs from the weathering of a diverse suite of rocks in its drainage basin. GSL is the remnant of a much larger lacustrine body, Lake Bonneville, and it has a long history of carbonate deposition. Inflow to the lake is from three major rivers that drain mountain ranges to the east and empty into the southern arm of the lake, from precipitation directly on the lake, and from minor groundwater inflow. Outflow is by evaporation. The greatest solute inputs are from calcium bicarbonate river waters mixed with sodium chloride-type springs and groundwaters. Prior to 1930 the lake concentration inversely tracked lake volume, which reflected climatic variation in the drainage, but since then salt precipitation and re-solution, primarily halite and mirabilite, have periodically modified lake-brine chemistry through density stratification and compositional differentiation. In addition, construction of a railway causeway has restricted circulation, nearly isolating the northern from the southern part of the lake, leading to halite precipitation in the north. These and other conditions have created brine differentiation, mixing, and fractional precipitation of salts as major factors in solute evolution. Pore fluids and diagenetic reactions have been identified as important sources and especially sinks for CaCO3, Mg, and K in the lake, depending on the concentration gradient and clays. ?? U.S. Geological Survey 2008.

Large subglacial lakes in East Antarctica at the onset of fast-flowing ice streams.

PubMed

Bell, Robin E; Studinger, Michael; Shuman, Christopher A; Fahnestock, Mark A; Joughin, Ian

2007-02-22

Water plays a crucial role in ice-sheet stability and the onset of ice streams. Subglacial lake water moves between lakes and rapidly drains, causing catastrophic floods. The exact mechanisms by which subglacial lakes influence ice-sheet dynamics are unknown, however, and large subglacial lakes have not been closely associated with rapidly flowing ice streams. Here we use satellite imagery and ice-surface elevations to identify a region of subglacial lakes, similar in total area to Lake Vostok, at the onset region of the Recovery Glacier ice stream in East Antarctica and predicted by ice-sheet models. We define four lakes through extensive, flat, featureless regions of ice surface bounded by upstream troughs and downstream ridges. Using ice velocities determined using interferometric synthetic aperture radar (InSAR), we find the onset of rapid flow (moving at 20 to 30 m yr(-1)) of the tributaries to the Recovery Glacier ice stream in a 280-km-wide segment at the downslope margins of these four subglacial lakes. We conclude that the subglacial lakes initiate and maintain rapid ice flow through either active modification of the basal thermal regime of the ice sheet by lake accretion or through scouring bedrock channels in periodic drainage events. We suggest that the role of subglacial lakes needs to be considered in ice-sheet mass balance assessments.

78 FR 41299 - Regattas and Marine Parades; Great Lakes Annual Marine Events

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-10

... and Marine Parades; Great Lakes Annual Marine Events AGENCY: Coast Guard, DHS. ACTION: Notice of... regattas and marine parades in the Captain of the Port Detroit zone from 9:00 a.m. on June 21, 2013 through... navigable waters immediately prior to, during, and immediately after regattas or marine parades. Enforcement...

Drainage in Shallow Peatlands of Marginal Upland Landscapes: DOC Losses from High Flow Events

NASA Astrophysics Data System (ADS)

Grand-Clement, E.; Anderson, K.; Luscombe, D.; Gatis, N.; Benaud, P.; Brazier, R.

2013-12-01

Peatlands are widely represented in northern Europe, especially in the UK. In the South West of England (i.e. Exmoor, Dartmoor and Bodmin moors), climate change puts their existence under threat: according to recent modelling work, marginal peatlands are highly vulnerable to future temperature and precipitation change and are likely to be the first to disappear from as early as 2050. Additionally, peat cutting and intensive drainage for agricultural reclamation in the 19th and 20th century, have modified the hydrological behaviour of these shallow peatlands and dried out the upper layers, causing oxidation, erosion and vegetation change. Such anthropogenic interventions directly impact on the storage of carbon, but also the provision of other ecosystem services, such as the supply of drinking water, and the support of specific and rare habitats. Large restoration programs involving the blocking of drainage ditches are currently under way throughout the UK but, to date, little is known about the consequences of such management approaches on overall Carbon stocks, and whether the restoration can revert ecosystems back to a state similar to that of undisturbed peatlands. In this context, Exmoor is particularly vulnerable due to its location at the southernmost margin of the UK peatlands' geographical extent, and its dense network of drainage ditches putting pressure on already very shallow peat resources. We hypothesise that monitoring of these peatlands may provide an ';early warning system' for climatic impacts that could affect more northerly sites in years to come, as climates change more significantly. The aim of this study is to look at the current impact of peatland degradation on water quality on Exmoor during rainfall-runoff events. Our experimental approach employs detailed, high resolution monitoring of selected ditches that are representative of damaged conditions on Exmoor, from small- (30 x 30cm ditches) through medium- (50x50cm), large- (1-2m ditches

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...

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)

A catastrophic meltwater flood event and the formation of the Hudson Shelf Valley

USGS Publications Warehouse

Thieler, E. Robert; Butman, Bradford; Schwab, William C.; Allison, Mead A.; Driscoll, Neal W.; Donnelly, John P.; Uchupi, Elazar

2007-01-01

The Hudson Shelf Valley (HSV) is the largest physiographic feature on the U.S. mid-Atlantic continental shelf. The 150-km long valley is the submerged extension of the ancestral Hudson River Valley that connects to the Hudson Canyon. Unlike other incised valleys on the mid-Atlantic shelf, it has not been infilled with sediment during the Holocene. Analyses of multibeam bathymetry, acoustic backscatter intensity, and high-resolution seismic reflection profiles reveal morphologic and stratigraphic evidence for a catastrophic meltwater flood event that formed the modern HSV. The valley and its distal deposits record a discrete flood event that carved 15-m high banks, formed a 120-km2 field of 3- to 6-m high bedforms, and deposited a subaqueous delta on the outer shelf. The HSV is inferred to have been carved initially by precipitation and meltwater runoff during the advance of the Laurentide Ice Sheet, and later by the drainage of early proglacial lakes through stable spillways. A flood resulting from the failure of the terminal moraine dam at the Narrows between Staten Island and Long Island, New York, allowed glacial lakes in the Hudson and Ontario basins to drain across the continental shelf. Water level changes in the Hudson River basin associated with the catastrophic drainage of glacial lakes Iroquois, Vermont, and Albany around 11,450 14C year BP (∼ 13,350 cal BP) may have precipitated dam failure at the Narrows. This 3200 km3 discharge of freshwater entered the North Atlantic proximal to the Gulf Stream and may have affected thermohaline circulation at the onset of the Intra-Allerød Cold Period. Based on bedform characteristics and fluvial morphology in the HSV, the maximum freshwater flux during the flood event is estimated to be ∼ 0.46 Sv for a duration of ∼ 80 days.

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

NASA Astrophysics Data System (ADS)

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

2015-10-01

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

Estimation of recharge through selected drainage wells and potential effects from well closure, Orange County, Florida

USGS Publications Warehouse

Bradner, L.A.

1996-01-01

Drainage wells have been used in Orange County, Florida, and surrounding areas to alleviate flooding and to control lake levels since 1904. Over 400 drainage wells have been drilled in the county, but many are now redundant because of surface drainage systems that have been installed within the last two or three decades. Most of the drainage wells emplace water into the Upper Floridan aquifer, a zone of high transmissivity within the Floridan aquifer system. In 1992, the Orange County Stormwater Management Department identified 23 wells that were considered noncritical or redundant for current drainage control. These wells were targeted for closure to eliminate maintenance and possible contamination problems. A 3-year study (1992 through 1994) encompassed several drainage basins in the county. Inflow to 18 of the 23 drainage wells on the noncritical list and the effects of closure of these noncritical wells on the potentiometric surface of the Upper Floridan aquifer were estimated. Three sites were chosen for intensive study and were used for further extrapolation to other noncritical sites. The total average annual recharge rate through the 18 selected wells was estimated to be 9 cubic feet per second, or about 6 million gallons per day. The highest rate of long-term recharge, 4.6 cubic feet per second, was to well H-35. Several wells on the noncritical list were already plugged or had blocked intakes. Yields, or the sum of surface-water outflows and drainage-well recharge, from the drainage basins ranged from 20 to 33 inches per year. In some of the basins, all the yield from the basin was recharge through a drainage well. In other basins, most of the yield was surface outflow through canals rather than to drainage wells. The removal of the recharge from closure of the wells was simulated by superposition in a three-dimensional ground-water flow model. As a second step in the model, water was also applied to two sites in western Orange County that could receive

Spatiotemporal trends in fish mercury from a mine-dominated ecosystem: Clear Lake, California.

PubMed

Suchanek, Thomas H; Eagles-Smith, Collin A; Slotton, Darell G; Harner, E James; Colwell, Arthur E; Anderson, Norman L; Mullen, Lauri H; Flanders, John R; Adam, David P; McElroy, Kenneth J

2008-12-01

Clear Lake, California, USA, receives acid mine drainage and mercury (Hg) from the Sulphur Bank Mercury Mine, a U.S. Environmental Protection Agency (U.S. EPA) Superfund Site that was active intermittently from 1873 to 1957 and partially remediated in 1992. Mercury concentrations were analyzed primarily in four species of Clear Lake fishes: inland silversides (Menidia beryllina, planktivore), common carp (Cyprinus carpio, benthic scavenger/omnivore), channel catfish (Ictalurus punctatus, benthic omnivorous predator), and largemouth bass (Micropterus salmoides, piscivorous top predator). These data represent one of the largest fish Hg data sets for a single site, especially in California. Spatially, total Hg (TotHg) in silversides and bass declined with distance from the mine, indicating that the mine site represents a point source for Hg loading to Clear Lake. Temporally, fish Hg has not declined significantly over 12 years since mine site remediation. Mercury concentrations were variable throughout the study period, with no monotonic trends of increase or decrease, except those correlated with boom and bust cycles of an introduced fish, threadfin shad (Dorosoma petenense). However, stochastic events such as storms also influence juvenile largemouth bass Hg as evidenced during an acid mine drainage overflow event in 1995. Compared to other sites regionally and nationally, most fish in Clear Lake exhibit Hg concentrations similar to other Hg-contaminated sites, up to approximately 2.0 mg/kg wet mass (WM) TotHg in largemouth bass. However, even these elevated concentrations are less than would be anticipated from such high inorganic Hg loading to the lake. Mercury in some Clear Lake largemouth bass exceeded all human health fish consumption guidelines established over the past 25 years by the U.S. Food and Drug Administration (1.0 mg/kg WM), the National Academy of Sciences (0.5 mg/kg WM), and the U.S. EPA (0.3 mg/kg WM). Mercury in higher trophic level fishes

Radiocarbon content of lignin-enriched fraction in core sediment from Lake Biwa, central Japan

NASA Astrophysics Data System (ADS)

Kitagawa, Hiroyuki; Lim, Jaesoo; Takemura, Keiji; Hayashida, Akira; Haraguchi, Tsuyoshi

2010-04-01

The transport and deposition of terrestrially derived organic matter (TOM) into lake and ocean is a key but poorly constrained aspect of the modern global carbon cycle. An attempt has been done for estimating a transport time of TOM from the drainage basin of Lake Biwa, the largest lake in Japan. We have determined the 14C contents of the lignin-enriched fraction of the core sediment from the central part of Lake Biwa. The age of lignin-enriched fraction at the deposition time was estimated to be 7.5 × 10 3 years for the last glacial interval. Even in Lake Biwa with more than 100 rivers from the relatively small drainage basin (3850 km 2), TOM was transported at very long time (>10 3 years).

Sources of polychlorinated biphenyls to Devils Swamp Lake near Baton Rouge, Louisiana

USGS Publications Warehouse

Van Metre, Peter C.; Wilson, Jennifer T.; Kimball, Briant A.

2006-01-01

Devils Swamp Lake near Baton Rouge, Louisiana, created in 1973 by dredging in Devils Swamp along the Mississippi River, is contaminated with polychlorinated biphenyls (PCBs) from historical industrial discharges. This study involved the investigation of the occurrence, distribution, and sources of PCBs in the lake, including the possible historical contribution of PCBs from a hazardous-chemical disposal facility by way of a wastewater drainage ditch that was used from 1971 to 1993. Six bed sediment cores from the lake and three bed sediment grab samples from the drainage ditch were collected; 61 subsamples from selected intervals in five of the six cores and the three grab samples from the ditch were analyzed for PCBs using an immunoassay screening method. Sixteen of the core subsamples and one ditch sample were analyzed for organochlorine pesticides, PCBs, polycyclic aromatic hydrocarbons (PAHs) (15 samples), and major and trace elements. PCB congener profiles and a factor analysis of congener composition indicate that PCBs in sediment from the drainage ditch and in lake sediment deposited near the canal since the mid-1980s are similar, which indicates the disposal facility, by way of the wastewater drainage ditch, is the source of the PCBs. Sediment from several hundred meters down the lake to the west, near where Bayou Baton Rouge enters the lake, had a different PCB composition and in a sample deposited in the early 1980s, a much higher concentration, indicating a second source of PCBs in the watershed of Bayou Baton Rouge. Large differences in PAHs and metals between sediment near the ditch and sediment near Bayou Baton Rouge support this conclusion. The identity of the Bayou Baton Rouge source(s) cannot be established using available data. The short duration and relatively high concentrations of PCBs from the bayou source indicate either a spill or a flood-related release-there was a large flood on the Mississippi River in 1983. Older (deeper) samples from

Regional maximum rainfall analysis using L-moments at the Titicaca Lake drainage, Peru

NASA Astrophysics Data System (ADS)

Fernández-Palomino, Carlos Antonio; Lavado-Casimiro, Waldo Sven

2017-08-01

The present study investigates the application of the index flood L-moments-based regional frequency analysis procedure (RFA-LM) to the annual maximum 24-h rainfall (AM) of 33 rainfall gauge stations (RGs) to estimate rainfall quantiles at the Titicaca Lake drainage (TL). The study region was chosen because it is characterised by common floods that affect agricultural production and infrastructure. First, detailed quality analyses and verification of the RFA-LM assumptions were conducted. For this purpose, different tests for outlier verification, homogeneity, stationarity, and serial independence were employed. Then, the application of RFA-LM procedure allowed us to consider the TL as a single, hydrologically homogeneous region, in terms of its maximum rainfall frequency. That is, this region can be modelled by a generalised normal (GNO) distribution, chosen according to the Z test for goodness-of-fit, L-moments (LM) ratio diagram, and an additional evaluation of the precision of the regional growth curve. Due to the low density of RG in the TL, it was important to produce maps of the AM design quantiles estimated using RFA-LM. Therefore, the ordinary Kriging interpolation (OK) technique was used. These maps will be a useful tool for determining the different AM quantiles at any point of interest for hydrologists in the region.

Hydrological network and classification of lakes on the Third Pole

NASA Astrophysics Data System (ADS)

Gao, Yang; Wang, Weicai; Yao, Tandong; Lu, Ning; Lu, Anxin

2018-05-01

The intensity and form of changes in closed lakes, upstream lakes and outflow lakes on the Third Pole (TP) differ based on their drainage mode. Researchers' insufficient understanding of the hydrological networks associated with lakes hampers studies of the relationship between lakes and climate. In this study, we establish a comprehensive hydrological network for each lake (>1 km2) on the TP using 106 Landsat images, 236 Chinese topographic maps, and SRTM DEM. Three-hundred-ninety-seven closed lakes, 488 upstream lakes and 317 outflow lakes totaling 3,5498.49 km2, 7,378.82 km2, and 3,382.29 km2, respectively, were identified on the TP using 2010 data. Two-hundred-thirty-four closed lakes were found to not be linked to upstream lakes. The remaining 163 closed lakes were connected to and fed by the 488 upstream lakes. The object-oriented analyses within this study indicated that more rapid changes occurred in the surface extent of closed lakes than in upstream lakes or outflow lakes on the TP from 1970 s to 2010. Furthermore, the water volume of the examined closed lakes was almost nine times greater than that of the upstream lakes from 2003 to 2009. All the examined closed lakes exhibited an obvious water volume change compared to the corresponding upstream lakes in the same basin. Furthermore, two case studies illustrate that the annual and seasonal dynamics associated with the changes in closed lakes may reflect climate change patterns, while the upstream lake dynamics may be more controlled by the lakeshore terrain and drainage characteristics. The lake inventory and hydrological network catalogued in this study provide a basis for developing a better understanding of lake response to climate change on the TP.

Extreme events in the sedimentary record of maar Lake Pavin: Implications for natural hazards assessment in the French Massif Central

NASA Astrophysics Data System (ADS)

Chassiot, Léo; Chapron, Emmanuel; Di Giovanni, Christian; Albéric, Patrick; Lajeunesse, Patrick; Lehours, Anne-Catherine; Meybeck, Michel

2016-06-01

A set of sedimentary cores, high resolution swath bathymetry and subbottom profiler data provides new insights on sedimentary processes in meromictic maar Lake Pavin, France. Three sedimentary environments (i.e., littoral, plateau and basin) have been identified in the lake from sediment composition using bulk organic geochemistry and the analysis of hydroacoustic images. Various forms of rapidly deposited layers (RDLs) have been identified and radiocarbon dated. An up to date stratigraphy of sedimentary events matching coeval RDLs across the lake is presented and illustrates a wide range of natural hazards linked to Lake Pavin during the last 2000 years. In AD 600, a sudden lake outburst triggered a slump deposit along with a 9 m lake-level drop that drove shifts in sedimentary organic matter composition. Outside the lake, outburst flood deposits have been described downstream and provide sedimentary evidence for this event. The lake-level drop also favored the generation of gravity reworking processes, as shown by (1) a regional earthquake-triggered large slope failure on the plateau connected to a mass-wasting deposit in the basin dated to AD 1300, and (2) a succession of turbidites in AD 1825 and AD 1860 contemporaneous to two historic earthquakes, suggesting that this lake is sensitive to earthquakes with a minimum epicentral intensity of V. Finally, past observations of lake water color changes in AD 1783 and AD 1936, similar to reports in other meromictic lakes, match iron-rich deposits identified in maar lake sediments and suggest that Lake Pavin could have undergone limnic eruptions.

A role for land surface forcing of North Atlantic climate and isotope signals during the 8.2kyr event?

NASA Astrophysics Data System (ADS)

Hopcroft, Peter; Valdes, Paul

2014-05-01

An important example of abrupt climate change occurred 8200 years ago in the North Atlantic and is generally known as the 8.2kyr event. This abrupt ~160 year cooling appears to coincide with the final drainage of the ice-dammed Lakes Agassiz and Ojibway. The resultant influx of meltwater to the North Atlantic is assumed to have perturbed the Atlantic Meridional Overturning circulation, reducing northward heat transport and causing widespread cooling. Numerous lines of evidence support this theory, with reconstructions showing changes in deep water formation, reductions in salinity and evidence of sea-level rise. Coupled general circulation model (GCM) simulations driven with realistic estimates of the meltwater flux show a regional cooling but fail to replicate the duration or the magnitude of this event in comparison with proxy archives. Meltwater injection was not the only rapid climate forcing in operation at this time. Drainage of the pro-glacial lakes would have had a profound effect on the boundary layer heat fluxes over North America, with potential teleconnections further afield. In this work we use an isotope-enabled version of the coupled GCM HadCM3 with boundary conditions appropriate for the time period of 9kyr (including ice sheets, greenhouse gases and orbital parameters). This model tracks oxygen isotopes throughout the hydrological cycle allowing more robust comparison with proxy archives. We analyse the impact of the removal of a lake area corresponding to Lakes Agassiz and Ojibway at this time and present sensitivity tests designed to analyse the contributions from lake removal, orographic change and the assumed isotopic content of the pro-glacial lakes. The results show a distinct pattern of cooling across North America (in the annual mean) with an apparent teleconnection to the Barents Sea, where there is warming associated with sea-ice reduction. The isotopic implications depend on the initial isotopic content of the pro-glacial lake. Assuming

Inorganic Carbon Isotopes and Chemical Characterization of Watershed Drainages, Barrow, Alaska, 2013

DOE Data Explorer

Heikoop, Jeffrey H.; Throckmorton, Heather M.; Wilson, Cathy J.; Newman, Brent D.

2016-02-22

Data include results from geochemical and isotopic analyses for samples collected in Barrow, Alaska during July and September 2013. Samples were soil pore waters from 17 drainages that could be interlake (basins with polygonal terrain), different-aged drain thaw lake basins (young, medium, old, or ancient), or a combination of different aged basins. Samples taken in different drainage flow types at three different depths at each location in and around the Barrow Environmental Observatory.

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

USGS Publications Warehouse

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

1990-01-01

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

Great Lakes

USGS Publications Warehouse

Edsall, Thomas A.; Mac, Michael J.; Opler, Paul A.; Puckett Haecker, Catherine E.; Doran, Peter D.

1998-01-01

The Great Lakes region, as defined here, includes the Great Lakes and their drainage basins in Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, and New York. The region also includes the portions of Minnesota, Wisconsin, and the 21 northernmost counties of Illinois that lie in the Mississippi River drainage basin, outside the floodplain of the river. The region spans about 9º of latitude and 20º of longitude and lies roughly halfway between the equator and the North Pole in a lowland corridor that extends from the Gulf of Mexico to the Arctic Ocean.The Great Lakes are the most prominent natural feature of the region (Fig. 1). They have a combined surface area of about 245,000 square kilometers and are among the largest, deepest lakes in the world. They are the largest single aggregation of fresh water on the planet (excluding the polar ice caps) and are the only glacial feature on Earth visible from the surface of the moon (The Nature Conservancy 1994a).The Great Lakes moderate the region’s climate, which presently ranges from subarctic in the north to humid continental warm in the south (Fig. 2), reflecting the movement of major weather masses from the north and south (U.S. Department of the Interior 1970; Eichenlaub 1979). The lakes act as heat sinks in summer and heat sources in winter and are major reservoirs that help humidify much of the region. They also create local precipitation belts in areas where air masses are pushed across the lakes by prevailing winds, pick up moisture from the lake surface, and then drop that moisture over land on the other side of the lake. The mean annual frost-free period—a general measure of the growing-season length for plants and some cold-blooded animals—varies from 60 days at higher elevations in the north to 160 days in lakeshore areas in the south. The climate influences the general distribution of wild plants and animals in the region and also influences the activities and distribution of the human

Lake acidification in the Adirondack Mountains of New York causes and consequences

Treesearch

Carl L. Schofield

1976-01-01

Current and historic geographic distributions of acidity in Adirondack lakes were examined in relation to regional edaphic, climatic, and physiographic features. Acid conditions are currently predominant in high elevation drainage lakes having small watershed/surface area ratios. Comparable levels of acidity were found only in small seepage lakes and bog ponds during...

Great Salt Lake, Utah

USGS Publications Warehouse

Stephens, Doyle W.; Gardner, Joe F.

1999-01-01

This document is intended as a source of general information and facts about Great Salt Lake, Utah. This U.S. Geological Survey information sheet answers frequently asked questions about Great Salt Lake. Topics include: History, salinity, brine shrimp, brine flies, migratory birds, and recreation. Great Salt Lake, the shrunken remnant of prehistoric Lake Bonneville, has no outlet. Dissolved salts accumulate in the lake by evaporation. Salinity south of the causeway has ranged from 6 percent to 27 percent over a period of 22 years (2 to 7 times saltier than the ocean). The high salinity supports a mineral industry that extracts about 2 million tons of salt from the lake each year. The aquatic ecosystem consists of more than 30 species of organisms. Harvest of its best-known species, the brine shrimp, annually supplies millions of pounds of food for the aquaculture industry worldwide. The lake is used extensively by millions of migratory and nesting birds and is a place of solitude for people. All this occurs in a lake that is located at the bottom of a 35,000-square-mile drainage basin that has a human population of more than 1.5 million.

Identification of nitrosamine precursors from urban drainage during storm events: A case study in southern China.

PubMed

Bei, Er; Liao, Xiaobin; Meng, Xiangting; Li, Shixiang; Wang, Jun; Sheng, Deyang; Chao, Meng; Chen, Zhuohua; Zhang, Xiaojian; Chen, Chao

2016-10-01

The drinking water sources of many cities in southern China are frequently contaminated by upstream urban drainage during storm events, which brings high concentrations of N-nitrosamine (NA) precursors and poses a threat to the safety of drinking water. We conducted two sampling campaigns during the heavy rain season in 2015 in one representative city in southern China. We detected that the concentration of N-nitrosodimethylamine formation potential (NDMA FP) in urban drainage during two storm events was 80-115 ng/L and the total formation potential concentration of nine nitrosamines (TNA9 FP) was 145-165 ng/L. To address the deteriorated water quality, 30 mg/L of powdered activated carbon (PAC) was fed into the water intake. PAC adsorption alone could remove 52% of NDMA FP and 52% of TNA FP, while the subsequent conventional process only removed 8% of TNA FP. We isolated six chemicals (N,N-benzyldimethylamine, 5-[(dimethylamino)methyl]-2-furanmethanol, N,N-dimethyl-3-aminophenol, N,N-dimethylethylamine, Ziram, and N,N-dimethylaniline) and confirmed them to be NA precursors. Among these NA precursors, Ziram was identified for the first time as a NA precursor that is formed via chloramination; its molar yield for NDMA was 6.73 ± 0.40%. Copyright © 2016 Elsevier Ltd. All rights reserved.

Summary of biological investigations relating to water quality in the Western Lake Michigan Drainages, Wisconsin and Michigan

USGS Publications Warehouse

Scudder, B.C.; Rheaume, S.J.; Parsons, S.R.; Lenz, B.N.

1996-01-01

Most biological studies related to waterquality conditions in the Western Lake Michigan Drainages have focused on populations and community structure of aquatic biota. Chemical concentrations in tissues of aquatic biota have been the next most common area of research. Our review suggests a paucity of data related to the health of all types of aquatic biota, especially amphibians, invertebrates, and reptiles; toxicity studies also were relatively uncommon. Overall, organisms primarily studied have been fish and invertebrates, although birds are most frequently examined in studies of organism health. The Fox/ Wolf Subbasin has been the focus of many more studies than the other subbasins, most likely because of the greater extent and severity of known water-quality problems in the Lower Fox River/Green Bay area over the past several decades and because it is the largest subbasin. Studies in the other subbasins are needed to adequately assess the water quality of these areas.

Landsat-based trend analysis of lake dynamics across northern permafrost regions

USGS Publications Warehouse

Nitze, Ingmar; Grosse, Guido; Jones, Benjamin M.; Arp, Christopher D.; Ulrich, Mathias; Federov, Alexander; Veremeeva, Alexandra

2017-01-01

Lakes are a ubiquitous landscape feature in northern permafrost regions. They have a strong impact on carbon, energy and water fluxes and can be quite responsive to climate change. The monitoring of lake change in northern high latitudes, at a sufficiently accurate spatial and temporal resolution, is crucial for understanding the underlying processes driving lake change. To date, lake change studies in permafrost regions were based on a variety of different sources, image acquisition periods and single snapshots, and localized analysis, which hinders the comparison of different regions. Here we present, a methodology based on machine-learning based classification of robust trends of multi-spectral indices of Landsat data (TM,ETM+, OLI) and object-based lake detection, to analyze and compare the individual, local and regional lake dynamics of four different study sites (Alaska North Slope, Western Alaska, Central Yakutia, Kolyma Lowland) in the northern permafrost zone from 1999 to 2014. Regional patterns of lake area change on the Alaska North Slope (-0.69%), Western Alaska (-2.82%), and Kolyma Lowland (-0.51%) largely include increases due to thermokarst lake expansion, but more dominant lake area losses due to catastrophic lake drainage events. In contrast, Central Yakutia showed a remarkable increase in lake area of 48.48%, likely resulting from warmer and wetter climate conditions over the latter half of the study period. Within all study regions, variability in lake dynamics was associated with differences in permafrost characteristics, landscape position (i.e. upland vs. lowland), and surface geology. With the global availability of Landsat data and a consistent methodology for processing the input data derived from robust trends of multi-spectral indices, we demonstrate a transferability, scalability and consistency of lake change analysis within the northern permafrost region.

Sources of seismic events in the cooling lava lake of Kilauea Iki, Hawaii

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

Chouet, B.

1979-05-10

Seismic surveys conducted in recent years revealed a suprisingly high and sustained activity of local seismic events originating in the partially frozen lava lake of Kilauea Iki crater, Hawaii. About 8000 events per day were counted in 1976 at the center of the lake with a seismograph having a peak magnification of 280,000 at 60 Hz. The activity was found to be uniform over the whole area above the inferred magma lens and very weak in the periphery of the lake. The frequency-amplitude relation for these shocks obeys the Ishimoto-Iida or Gutenberg-Richter law very well, with a b value ofmore » 1.19( +- 0.06). Locations of a few selected events indicate that they occur both above and below the layer of melt, although the seismic activity appears to be much higher in the upper crust. Whenever clear, the first motion is always outward from the source, suggesting that a crack opening under tensile stress owing to cooling is the responsible source mechanism. A simple model of a circular tensile crack nucleating at a point and growing at subsonic velocity can match the far-field P wave from these sources fairly well. Typical parameters for a large event inferred from the model are the following: radius, 2.7 m; maximum static tensile displacement between crack faces, 2.9..mu..; cavity volume, 4.4 x 10/sup -5/ m/sup 3/; and a seismic moment tensor with diagonal elements only, having the values 3.8 x 10/sup 2/exclamation2, 4.5 x 10/sup 12/, and 3.8 x 10/sup 12/ dyn cm. The magnitude of the event is about -1, and its stress drop is of the order of 0.01 bar. A Q as low as 10 is required to satisfy the shape of the observed wave forms. The total cavity volume integrated over all cracks which is generated daily in the upper crust of Kilauea Iki is of the order of 1--20 m/sup 3/. An alternate interpretation of the data, the seismic activity as reflecting the extension by up to several tens of centimeters of long existing cracks rather than the formation of new cracks.« less

Constraints on Lake Agassiz discharge through the late-glacial Champlain Sea (St. Lawrence Lowlands, Canada) using salinity proxies and an estuarine circulation model

USGS Publications Warehouse

Katz, B.; Najjar, R.G.; Cronin, T.; Rayburn, J.; Mann, M.E.

2011-01-01

During the last deglaciation, abrupt freshwater discharge events from proglacial lakes in North America, such as glacial Lake Agassiz, are believed to have drained into the North Atlantic Ocean, causing large shifts in climate by weakening the formation of North Atlantic Deep Water and decreasing ocean heat transport to high northern latitudes. These discharges were caused by changes in lake drainage outlets, but the duration, magnitude and routing of discharge events, factors which govern the climatic response to freshwater forcing, are poorly known. Abrupt discharges, called floods, are typically assumed to last months to a year, whereas more gradual discharges, called routing events, occur over centuries. Here we use estuarine modeling to evaluate freshwater discharge from Lake Agassiz and other North American proglacial lakes into the North Atlantic Ocean through the St. Lawrence estuary around 11.5 ka BP, the onset of the Preboreal oscillation (PBO). Faunal and isotopic proxy data from the Champlain Sea, a semi-isolated, marine-brackish water body that occupied the St. Lawrence and Champlain Valleys from 13 to 9 ka, indicate salinity fell about 7-8 (range of 4-11) around 11.5 ka. Model results suggest that minimum (1600 km3) and maximum (9500 km3) estimates of plausible flood volumes determined from Lake Agassiz paleoshorelines would produce the proxy-reconstructed salinity decrease if the floods lasted <1 day to 5 months and 1 month to 2 years, respectively. In addition, Champlain Sea salinity responds very quickly to the initiation (within days) and cessation (within weeks) of flooding events. These results support the hypothesis that a glacial lake flood, rather than a sustained routing event, discharged through the St. Lawrence Estuary during the PBO. ?? 2011 Elsevier Ltd.

Hydrogeologic controls on the groundwater interactions with an acidic lake in karst terrain, Lake Barco, Florida

USGS Publications Warehouse

Lee, T.M.

1996-01-01

Transient groundwater interactions and lake stage were simulated for Lake Barco, an acidic seepage lake in the mantled karst of north central Florida. Karst subsidence features affected groundwater flow patterns in the basin and groundwater fluxes to and from the lake. Subsidence features peripheral to the lake intercepted potential groundwater inflow and increased leakage from the shallow perimeter of the lake bed. Simulated groundwater fluxes were checked against net groundwater flow derived from a detailed lake hydrologic budget with short-term lake evaporation computed by the energy budget method. Discrepancies between modeled and budget-derived net groundwater flows indicated that the model underestimated groundwater inflow, possibly contributed to by transient water table mounding near the lake. Recharge from rainfall reduced lake leakage by 10 to 15 times more than it increased groundwater inflow. As a result of the karst setting, the contributing groundwater basin to the lake was 2.4 ha for simulated average rainfall conditions, compared to the topographically derived drainage basin area of 81 ha. Short groundwater inflow path lines and rapid travel times limit the contribution of acid-neutralizing solutes from the basin, making Lake Barco susceptible to increased acidification by acid rain.

Large Rock-Slope Failures Impacting on Lakes - Event Reconstruction and Interaction Analysis in Two Alpine Regions Using Sedimentology and Geophysics

NASA Astrophysics Data System (ADS)

Knapp, S.; Anselmetti, F.; Gilli, A.; Krautblatter, M.; Hajdas, I.

2016-12-01

Massive rock-slope failures are responsible for more than 60% of all catastrophic landslides disasters. Lateglacial and Holocene rock-slope failures often occur as multistage failures, but we have only limited datasets to reconstruct detailed stages and still aim at improving our knowledge of mobility processes. In this context, studying lakes will become more and more important for two main reasons. On the one hand, the lake background sedimentation acts as a natural chronometer, which enables the stratigraphic positioning of events and helps to reconstruct the event history. This way we will be able to improve our knowledge on multistage massive rock-slope failures. On the other hand, climate warming forces us to face an increase of lakes forming due to glacial melting, leading to new hazardous landscape settings. We will be confronted with complex reaction chains and feedback loops related to rock-slope instability, stress adaptation, multistage rock-slope failures, lake tsunamis, entrainment of water and fines, and finally lubrication. As a result, in future we will have to deal more and more with failed rock material impacting on lakes with much longer runout-paths than expected, and which we have not been able to reconstruct in our models so far. Here we want to present the key findings of two of our studies on lake sediments related to large rock-slope failures: We used reflection seismic profiles and sediment cores for the reconstruction of the rockfall history in the landslide-dammed Lake Oeschinen in the Bernese Oberland, Switzerland, where we detected and dated ten events and correlated them to (pre)historical data. As a second project, we have been working on the mobility processes of the uppermost sediments deposited during the late event stadium of the Eibsee rock avalanche at Mount Zugspitze in the Bavarian Alps, Germany. In the reflection seismic profiles we detected sedimentary structures that show high levels of fluidization and thus would hint at

Mono Lake, California as seen from STS-59

NASA Image and Video Library

1994-04-14

STS059-154-160 (9-20 April 1994) --- Orient with Mono Lake, California at the lower right; then the view is westward across the Sierra Nevada into the San Joaquin River drainage. A tiny network of ski trails can be seen on the Mono Lake side of the Sierras, on a line between Mono Lake and the snow-free San Joaquin headwaters. The ski trails mark Mammoth Mountain, where SRL investigators are studying microwave measurements of the water content of snowpacks. Linhof camera.

Annual maximum and minimum lake levels for Indiana, 1942-85

USGS Publications Warehouse

Fowler, Kathleen K.

1988-01-01

Indiana has many natural and manmade lakes. Lake-level data are available for 217 lakes. These data were collected during water years 1942-85 by use of staff gages and, more recently, continuous recorders. The period of record at each site ranges from 1 to 43 years. Data from the lake stations have been compiled, and maximum and minimum lake levels for each year of record are reported. In addition to annual maximum and minimum lake levels, each lake station is described by gage location, surface area, drainage area, period of record, datum of gage, gage type, established legal level, lake level control, inlets and outlets, and extremes for the period of record. 

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.

The Mungo Mega-Lake Event, Semi-Arid Australia: Non-Linear Descent into the Last Ice Age, Implications for Human Behaviour

PubMed Central

Fitzsimmons, Kathryn E.; Stern, Nicola; Murray-Wallace, Colin V.; Truscott, William; Pop, Cornel

2015-01-01

The Willandra Lakes complex is one of the few locations in semi-arid Australia to preserve both paleoenvironmental and Paleolithic archeological archives at high resolution. The stratigraphy of transverse lunette dunes on the lakes’ downwind margins record a late Quaternary sequence of wetting and drying. Within the Willandra system, the Lake Mungo lunette is best known for its preservation of the world’s oldest known ritual burials, and high densities of archeological traces documenting human adaptation to changing environmental conditions over the last 45 ka. Here we identify evidence at Lake Mungo for a previously unrecognised short-lived, very high lake filling phase at 24 ka, just prior to the Last Glacial Maximum. Mega-lake Mungo was up to 5 m deeper than preceding or subsequent lake full events and represented a lake volume increase of almost 250%. Lake Mungo was linked with neighboring Lake Leaghur at two overflow points, creating an island from the northern part of the Mungo lunette. This event was most likely caused by a pulse of high catchment rainfall and runoff, combined with neotectonic activity which may have warped the lake basin. It indicates a non-linear transition to more arid ice age conditions. The mega-lake restricted mobility for people living in the area, yet archeological traces indicate that humans rapidly adapted to the new conditions. People repeatedly visited the island, transporting stone tools across water and exploiting food resources stranded there. They either swam or used watercraft to facilitate access to the island and across the lake. Since there is no evidence for watercraft use in Australia between initial colonization of the continent prior to 45 ka and the mid-Holocene, repeated visits to the island may represent a resurrection of waterfaring technologies following a hiatus of at least 20 ky. PMID:26083665

75 FR 20920 - Safety Zone; Lake Havasu Grand Prix, Lake Havasu, AZ

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-22

...-AA00 Safety Zone; Lake Havasu Grand Prix, Lake Havasu, AZ AGENCY: Coast Guard, DHS. ACTION: Temporary... of Lake Havasu on the Colorado River in Lake Havasu City, Arizona for the Lake Havasu Grand Prix... established in support of the Lake Havasu Grand Prix, a marine event that includes participating vessels...

The Socio-hydrology of Bangalore's Lake System and implications for Urban Water Security

NASA Astrophysics Data System (ADS)

Srinivasan, V.; Roy, S.

2017-12-01

Bengaluru city has experienced unprecedented growth in recent decades. If the city is to sustain growth and claim its position as a "global" high-tech city, it must be able to secure sufficient water supply and also create a healthy livable environment. With the city's many lakes vanishing due to rapid urbanisation, depletion of groundwater as a result of overuse in the peri-urban areas, and lack of proper underground drainage system and sewage treatment plants, Bangalore is now grappling with issues of imminent water crisis, inequitable access to water supply, and public health hazards. In this context, the restoration of Bangalore's lakes has been promoted as a panacea for its flooding, water stress, and wastewater problems. It has been argued that lakes can store storm water and recycled wastewater and avoid the need for potentially destructive, expensive schemes that may destroy biodiversity rich aquatic ecosystems and forests. Bangalore's lakes are linked by the drainage channels to form a cascade; overflow from each lake flows to the next lake downstream. Yet, most efforts have tended to view the lakes in isolation. This study of the hydrology of Bangalore's lake system in its entirety simulates the lake system as a whole. The study explores approaches to management and theor impact on urban water security.

The changing spatio-temporal dynamics of thaw lake development, Seward Peninsula, Alaska.

NASA Astrophysics Data System (ADS)

Cooper, Michael; Rees, Gareth; Bartsch, Annett

2014-05-01

Contemporary anthropogenic climatic warming is having an accelerated, and more pronounced effect upon Arctic regions than any other environment on Earth. Increased surface temperatures have led to widespread permafrost degradation and a shift in dynamics. One landscape manifestation of localised permafrost decay, seen to be ubiquitous across low-lying tundra regions of Alaska, Canada and Siberia, is the thermokarst lake - or 'thaw' lake. These features are seen to be truly dynamic, with a relatively rapid evolution and decay. The exact impacts of climatic perturbation on thaw lake development are in contention; however, recent studies have suggested an increased vulnerability of these features, owing to the susceptibility of the fundamental processes of initiation, expansion and drainage to climatic variation. It is often hypothesised that with current trends, thaw lakes will see a net increase in expansion rate, and areal extent, with a potential for increased drainage events. Increased permafrost thaw and thermokarst activity has also led to shifts in biogeochemical cycles, leading to an amplified release from large carbon reservoirs currently sequestered within permafrost. An example of carbon release exhibited from thaw lakes is that of methane ebullition (gas bubble formation); this has been theorised to have the potential to initiate a major positive climatic feedback leading to a continued rise in global temperatures. Due to the remote nature and large area over which these landforms occur, remotely sensed data has been widely used in order to both accurately classify features and measure change over spatially large and great temporal extents. As well as studies interpreting data collected in the visible and near-infrared spectra, studies have recently made use of radar or microwave products in order to capture imagery avoiding adverse atmospheric conditions, most notably cloud cover. Data from Envisat ASAR operating in Wide Swath Mode was acquired for this

Is reduced benthic flux related to the Diporeia decline? Analysis of spring blooms and whiting events in Lake Ontario

USGS Publications Warehouse

Watkins, James M.; Rudstam, Lars G.; Crabtree, Darran L.; Walsh, Maureen

2013-01-01

Benthic monitoring by USGS off the southern shore of Lake Ontario from October 1993 to October 1995 provides a detailed view of the early stages of the decline of the native amphipod Diporeia. A loss of the 1994 and 1995 year classes of Diporeia preceded the disappearance of the native amphipod at sites near Oswego and Rochester at depths from 55 to 130 m. In succeeding years, Diporeia populations continued to decline in Lake Ontario and were nearly extirpated by 2008. Explanations for Diporeia 's decline in the Great Lakes include several hypotheses often linked to the introduction and expansion of exotic zebra and quagga mussels (Dreissena sp.). We compare the timeline of the Diporeia decline in Lake Ontario with trends in two sources of organic matter to the sediments — spring diatom blooms and late summer whiting events. The 1994–95 decline of Diporeia coincided with localized dreissenid effects on phytoplankton in the nearshore and a year (April 1994 to May 1995) of decreased flux of organic carbon recorded by sediment traps moored offshore of Oswego. Later declines of profundal (> 90 m) Diporeia populations in 2003 were poorly associated with trends in spring algal blooms and late summer whiting events. Lake Ontario/Diporeia/Dreissena/remote sensing.

Efficient meltwater drainage through supraglacial streams and rivers on the southwest Greenland ice sheet.

PubMed

Smith, Laurence C; Chu, Vena W; Yang, Kang; Gleason, Colin J; Pitcher, Lincoln H; Rennermalm, Asa K; Legleiter, Carl J; Behar, Alberto E; Overstreet, Brandon T; Moustafa, Samiah E; Tedesco, Marco; Forster, Richard R; LeWinter, Adam L; Finnegan, David C; Sheng, Yongwei; Balog, James

2015-01-27

Thermally incised meltwater channels that flow each summer across melt-prone surfaces of the Greenland ice sheet have received little direct study. We use high-resolution WorldView-1/2 satellite mapping and in situ measurements to characterize supraglacial water storage, drainage pattern, and discharge across 6,812 km(2) of southwest Greenland in July 2012, after a record melt event. Efficient surface drainage was routed through 523 high-order stream/river channel networks, all of which terminated in moulins before reaching the ice edge. Low surface water storage (3.6 ± 0.9 cm), negligible impoundment by supraglacial lakes or topographic depressions, and high discharge to moulins (2.54-2.81 cm⋅d(-1)) indicate that the surface drainage system conveyed its own storage volume every <2 d to the bed. Moulin discharges mapped inside ∼52% of the source ice watershed for Isortoq, a major proglacial river, totaled ∼41-98% of observed proglacial discharge, highlighting the importance of supraglacial river drainage to true outflow from the ice edge. However, Isortoq discharges tended lower than runoff simulations from the Modèle Atmosphérique Régional (MAR) regional climate model (0.056-0.112 km(3)⋅d(-1) vs. ∼0.103 km(3)⋅d(-1)), and when integrated over the melt season, totaled just 37-75% of MAR, suggesting nontrivial subglacial water storage even in this melt-prone region of the ice sheet. We conclude that (i) the interior surface of the ice sheet can be efficiently drained under optimal conditions, (ii) that digital elevation models alone cannot fully describe supraglacial drainage and its connection to subglacial systems, and (iii) that predicting outflow from climate models alone, without recognition of subglacial processes, may overestimate true meltwater export from the ice sheet to the ocean.

Efficient meltwater drainage through supraglacial streams and rivers on the southwest Greenland ice sheet

PubMed Central

Smith, Laurence C.; Chu, Vena W.; Yang, Kang; Gleason, Colin J.; Pitcher, Lincoln H.; Rennermalm, Asa K.; Legleiter, Carl J.; Behar, Alberto E.; Overstreet, Brandon T.; Moustafa, Samiah E.; Tedesco, Marco; Forster, Richard R.; LeWinter, Adam L.; Finnegan, David C.; Sheng, Yongwei; Balog, James

2015-01-01

Thermally incised meltwater channels that flow each summer across melt-prone surfaces of the Greenland ice sheet have received little direct study. We use high-resolution WorldView-1/2 satellite mapping and in situ measurements to characterize supraglacial water storage, drainage pattern, and discharge across 6,812 km2 of southwest Greenland in July 2012, after a record melt event. Efficient surface drainage was routed through 523 high-order stream/river channel networks, all of which terminated in moulins before reaching the ice edge. Low surface water storage (3.6 ± 0.9 cm), negligible impoundment by supraglacial lakes or topographic depressions, and high discharge to moulins (2.54–2.81 cm⋅d−1) indicate that the surface drainage system conveyed its own storage volume every <2 d to the bed. Moulin discharges mapped inside ∼52% of the source ice watershed for Isortoq, a major proglacial river, totaled ∼41–98% of observed proglacial discharge, highlighting the importance of supraglacial river drainage to true outflow from the ice edge. However, Isortoq discharges tended lower than runoff simulations from the Modèle Atmosphérique Régional (MAR) regional climate model (0.056–0.112 km3⋅d−1 vs. ∼0.103 km3⋅d−1), and when integrated over the melt season, totaled just 37–75% of MAR, suggesting nontrivial subglacial water storage even in this melt-prone region of the ice sheet. We conclude that (i) the interior surface of the ice sheet can be efficiently drained under optimal conditions, (ii) that digital elevation models alone cannot fully describe supraglacial drainage and its connection to subglacial systems, and (iii) that predicting outflow from climate models alone, without recognition of subglacial processes, may overestimate true meltwater export from the ice sheet to the ocean. PMID:25583477

The evolution of a thermokarst-lake landscape: Late Quaternary permafrost degradation and stabilization in interior Alaska

USGS Publications Warehouse

Edwards, Mary E.; Grosse, Guido; Jones, Benjamin M.; McDowell, Patricia F.

2016-01-01

Thermokarst processes characterize a variety of ice-rich permafrost terrains and often lead to lake formation. The long-term evolution of thermokarst landscapes and the stability and longevity of lakes depend upon climate, vegetation and ground conditions, including the volume of excess ground ice and its distribution. The current lake status of thermokarst-lake landscapes and their future trajectories under climate warming are better understood in the light of their long-term development. We studied the lake-rich southern marginal upland of the Yukon Flats (northern interior Alaska) using dated lake-sediment cores, observations of river-cut exposures, and remotely-sensed data. The region features thick (up to 40 m) Quaternary deposits (mainly loess) that contain massive ground ice. Two of three studied lakes formed ~ 11,000–12,000 cal yr BP through inferred thermokarst processes, and fire may have played a role in initiating thermokarst development. From ~ 9000 cal yr BP, all lakes exhibited steady sedimentation, and pollen stratigraphies are consistent with regional patterns. The current lake expansion rates are low (0 to < 7 cm yr− 1 shoreline retreat) compared with other regions (~ 30 cm yr− 1 or more). This thermokarst lake-rich region does not show evidence of extensive landscape lowering by lake drainage, nor of multiple lake generations within a basin. However, LiDAR images reveal linear “corrugations” (> 5 m amplitude), deep thermo-erosional gullies, and features resembling lake drainage channels, suggesting that highly dynamic surface processes have previously shaped the landscape. Evidently, widespread early Holocene permafrost degradation and thermokarst lake initiation were followed by lake longevity and landscape stabilization, the latter possibly related to establishment of dense forest cover. Partial or complete drainage of three lakes in 2013 reveals that there is some contemporary landscape dynamism. Holocene landscape

Spatiotemporal analysis of microbial community dynamics during seasonal stratification events in a freshwater lake (Grand Lake, OK, USA)

PubMed Central

Morrison, Jessica M.; Baker, Kristina D.; Zamor, Richard M.; Nikolai, Steve; Elshahed, Mostafa S.

2017-01-01

Many freshwater lakes undergo seasonal stratification, where the formation of phototrophic blooms in the epilimnion and subsequent sedimentation induces hypoxia/anoxia in the thermocline and hypolimnion. This autochthonously produced biomass represents a major seasonal organic input that impacts the entire ecosystem. While the limnological aspects of this process are fairly well documented, relatively little is known regarding the microbial community response to such events, especially in the deeper anoxic layers of the water column. Here, we conducted a spatiotemporal survey of the particle-associated and free-living microbial communities in a warm monomictic freshwater reservoir (Grand Lake O’ the Cherokees) in northeastern Oklahoma, USA. Pre-stratification samples (March) harbored a homogeneous community throughout the oxygenated water column dominated by typical oligotrophic aquatic lineages (acl clade within Actinobacteria, and Flavobacterium within the Bacteroidetes). The onset of phototrophic blooming in June induced the progression of this baseline community into two distinct trajectories. Within the oxic epilimnion, samples were characterized by the propagation of phototrophic (Prochlorococcus), and heterotrophic (Planctomycetes, Verrucomicrobia, and Beta-Proteobacteria) lineages. Within the oxygen-deficient thermocline and hypolimnion, the sedimentation of surface biomass induced the development of a highly diverse community, with the enrichment of Chloroflexi, “Latescibacteria”, Armatimonadetes, and Delta-Proteobacteria in the particle-associated fraction, and Gemmatimonadetes and “Omnitrophica” in the free-living fraction. Our work documents the development of multiple spatially and temporally distinct niches during lake stratification, and supports the enrichment of multiple yet-uncultured and poorly characterized lineages in the lake’s deeper oxygen-deficient layers, an ecologically relevant microbial niche that is often overlooked in

Hinterland drainage closure and lake formation in response to middle Eocene Farallon slab removal, Nevada, U.S.A.

NASA Astrophysics Data System (ADS)

Smith, M. Elliot; Cassel, Elizabeth J.; Jicha, Brian R.; Singer, Brad S.; Canada, Andrew S.

2017-12-01

Hinterland basins can accumulate high resolution archives of orogenic processes and continental climate, but are challenging to reconstruct due to tectonic overprinting and the inherent complexity of their lithofacies assemblages. The Cordilleran hinterland of northeast Nevada has been interpreted to have overlain a flattened Farallon slab from the Late Cretaceous to Eocene. Slab removal and advection of asthenospheric mantle beneath Nevada have been invoked to explain a southwestward migrating wave of Eocene to Oligocene volcanism and proposed as a driver for topographic uplift. However, the timing of slab removal and possible subsequent delamination of North American lithospheric mantle can only ambiguously be related to the surface record. Subsequent Neogene extension and basin filling has complicated the correlation and interpretation of strata that record these events. Here we apply single crystal sanidine 40Ar/39Ar geochronology to 26 ash beds in northeast Nevada to reconstruct Paleogene geographic and hydrologic evolution. We use these ages and legacy geochronology to compare lithofacies and isotope proxy records of meteoric waters to regional tectonics and global climate, and assess competing tectonic interpretations for lake basin formation. Lakes formed locally prior to ca. 48.7 Ma in northeast Nevada, coeval with foreland lakes of the Green River Formation. The most expansive phase of lacustrine deposition resulted in onlap onto locally derived fluvial deposits and folded Paleozoic bedrock, and occurred between ca. 43.4 and ca. 40.8 Ma. Elko Formation strata exhibit a basin-wide transition from fluvial-lacustrine to fluctuating profundal lithofacies at ca. 42.7 Ma, suggesting a shift towards regional hydrologic closure. The stromatolitic upper Elko Formation is intercalated with ash fall tuffs and several partially welded to unwelded ignimbrites from increasingly proximal volcanism. Elko Formation deposition ended by ca. 40.4 Ma. 40Ar/39Ar ages for seven

Mladotice Lake, Czechia: The unique genesis and evolution of the lake basin

NASA Astrophysics Data System (ADS)

Janský, Bohumír; Šobr, Miroslav; Kliment, Zdeněk; Chalupová, Dagmar

2016-04-01

The Mladotice Lake is a lake of unique genetic type in Czechia. In May 1872 a landslide as a result an extreme rainfall event occurred in western Czechia, blocking the Mladoticky stream valley and creating the Mladotice Lake. The 1952 and 1975 air images document that collective farming had a great impact on the lake basin evolution when balks and field terraces were removed and fields were made much larger. Because of this change in land use we expected higher soil erosion and a related increase in the sedimentation rate. First bathymetric measurements of the newly created lake were carried out in 1972 and were repeated in 1999, in 2003 and in 2014. Our analysis of the sedimentary record aims to identify the sediment stratigraphy, its basic physical and chemical properties, isotope content and thin sections yield a detailed temporal resolution of the sedimentation chronology. In some areas a sediment thickness of 4 m was detected. Hence, the average sedimentation rate is from 2.2 to 2.7 cm per year. KEY WORDS: Mladotice Lake - extreme rainfall event - landslide - land use changes - flood events - bathymetric measurements - sedimentation dynamics - stratigraphy and geochemistry of lake sediments - analyses of isotopes - sedimentation rates.

Accurate seismic phase identification and arrival time picking of glacial icequakes

NASA Astrophysics Data System (ADS)

Jones, G. A.; Doyle, S. H.; Dow, C.; Kulessa, B.; Hubbard, A.

2010-12-01

A catastrophic lake drainage event was monitored continuously using an array of 6, 4.5 Hz 3 component geophones in the Russell Glacier catchment, Western Greenland. Many thousands of events and arrival time phases (e.g., P- or S-wave) were recorded, often with events occurring simultaneously but at different locations. In addition, different styles of seismic events were identified from 'classical' tectonic earthquakes to tremors usually observed in volcanic regions. The presence of such a diverse and large dataset provides insight into the complex system of lake drainage. One of the most fundamental steps in seismology is the accurate identification of a seismic event and its associated arrival times. However, the collection of such a large and complex dataset makes the manual identification of a seismic event and picking of the arrival time phases time consuming with variable results. To overcome the issues of consistency and manpower, a number of different methods have been developed including short-term and long-term averages, spectrograms, wavelets, polarisation analyses, higher order statistics and auto-regressive techniques. Here we propose an automated procedure which establishes the phase type and accurately determines the arrival times. The procedure combines a number of different automated methods to achieve this, and is applied to the recently acquired lake drainage data. Accurate identification of events and their arrival time phases are the first steps in gaining a greater understanding of the extent of the deformation and the mechanism of such drainage events. A good knowledge of the propagation pathway of lake drainage meltwater through a glacier will have significant consequences for interpretation of glacial and ice sheet dynamics.

Lake Okeechobee seepage monitoring network

USGS Publications Warehouse

McKenzie, Donald J.

1973-01-01

This report summarizes the data collected at the five original monitoring sites along the south shore of Lake Okeechobee from January 29, 1970 to June 28, 1972. In order to use the hydrographs in this report to full advantage, they should be studied in conjunction with Meyer's graphs and text (1971). During steady-state conditions, water seeps from the lake through the filtercake and through the aquifers beneath the dike. At those sites where the filtercake is missing, or has about the same permeability as the aquifers, the seepage from the lake is about equivalent to the flow through the aquifers. Present data are insufficient to determine whether or not filtercake buildup has reduced seepage. No appreciable change in drainage occurred during the observed period.

MERGANSER - A Predictive Model of Mercury in Fish and Loons in New England Lakes

NASA Astrophysics Data System (ADS)

Moore, R. B.; Shanley, J. B.; Smith, R. A.; Miller, E. K.; Simcox, A.; Kamman, N. C.; Nacci, D. E.; Robinson, K. W.; Johnston, J. M.; Hughes, M.; Johnston, C. M.; Williams, K.; Graham, J.; King, S.

2010-12-01

MERGANSER (MERcury Geo-spatial AssessmeNtS for the New England Region) is an empirical least squares multiple regression model using atmospheric deposition of mercury (Hg) and readily obtainable lake and watershed features to predict fish and common loon Hg in New England lakes. We modeled lakes larger than 8 ha and with drainage area completely within the USA (4404 lakes), using 3827 fish (12 species) and loon Hg values from 420 lakes. MERGANSER predictor variables included Hg deposition, watershed alkalinity, percent wetlands, percent forest canopy, percent agriculture, drainage area, population, mean annual temperature and watershed slope. The model returns fish tissue or loon blood Hg for user-entered species and length. MERGANSER explained 63% of the variance in fish fillet and loon Hg concentrations. MERGANSER predicted that 32-cm small mouth bass had a median Hg concentration of 0.53 µg g-1 and exceeded EPA’s maximum contaminant level (MCL) of 0.3 µg/g Hg in 90% of New England lakes. Common loon had a median Hg concentration of 1.07 µg g-1 and was in the moderate or higher risk category of >1 µg/g Hg in 58% of New England lakes.

Repeated drainage from megathrusts during episodic slow slip

NASA Astrophysics Data System (ADS)

Nakajima, Junichi; Uchida, Naoki

2018-05-01

Pore-fluid pressure levels are considered to regulate the frictional strength and slip behaviour at megathrusts, where the largest earthquakes on Earth occur. Some analyses have suggested that the breaking of permeability seals during megathrust earthquakes causes subsequent drainage from the megathrust. However, it is poorly understood whether drainage follows frequent occurrences of episodic slow slip events. Here we analyse seismic waveform data beneath Kanto, Japan, for the period from 2004 to 2015 and show that seismicity rates and seismic attenuation above the megathrust of the Philippine Sea slab change cyclically in response to accelerated slow slip. These observations are interpreted to represent intensive drainage during slow slip events that repeat at intervals of approximately one year and subsequent migration of fluids into the permeable overlying plate. Our observations suggest that if slow slip events occur under an impermeable overlying plate, fluids draining due to slow slip events could be forced to channel within the megathrust, potentially enhancing pore-fluid pressure at an up-dip, locked seismogenic megathrust. This process might increase the potential to trigger large earthquakes near slow slip areas. Although stress transfer is recognized as an important factor for triggering megathrust failure, fluid transfer accompanied by episodic slow slip events will thus play an additional and crucial part in megathrust weakening.

Limnological data from selected lakes in the San Francisco Bay region, California

USGS Publications Warehouse

Britton, Linda J.; Ferreira, Rodger F.; Averett, Robert C.

1974-01-01

The largest reservoir, Lake Berryessa, has a volume of 1,600,000 acre-ft (1,975 hm3), with a drainage. area of 576 mi2 (1,490 km2 ). Pilarcitos Lake is one of the smallest reservoirs, with a volume of 3,100 acre-ft (3. 8 hm3) and a drainage area of 3. 80 mi 2 (9.84km2). Eleven of the 21 reservoirs are open to the public for recreation. The most intensive shoreline development and use is at Lake Berryessa and Lake Merced. All but three of the 21 reservoirs (not including Upper Crystal Springs Reservoir) were thermally stratified during the summer. Eight of the reservoirs showed evidence of dissolvedoxygen depletion during the summer. Lafayette Reservoir and Loch Lomond are mechanically aerated in order to increase the dissolved-oxygen concentration and lower the surface water temperature. The lake waters ranged from the hard (320 mg/1 CaC03) of Calero Reservoir, to the soft (27 mg/1 CaC03) of Upper Crystal Springs Reservoir. Drainage from abandoned mercury mines in Santa Clara County has resulted in mercury concentrations in Calero and Lexington Reservoir fish which exceed U.S. Food and Drug limitations (0.5 μ/g) for acceptability of mercury in fish used for human food. In Loch Lomond, four major production periods of the blue-green algae, Anabaena sp. , occurred from May to October, 1967-69. Blue-green algae were the most numerous algae in Lake Del Valle from March through July 1971, with 5,400 blue-green algal organisms per millilitre collected in April.

Concordance of nuclear and mitochondrial DNA markers in detecting a founder event in Lake Clark sockeye salmon

USGS Publications Warehouse

Ramstad, Kristina M.; Woody, Carol Ann; Habicht, Chris; Sage, G. Kevin; Seeb, James E.; Allendorf, Fred W.

2007-01-01

Genetic bottleneck effects can reduce genetic variation, persistence probability, and evolutionary potential of populations. Previous microsatellite analysis suggested a bottleneck associated with a common founding of sock-eye salmon Oncorhynchus nerka populations of Lake Clark, Alaska, about 100 to 400 generations ago. The common foundingevent occurred after the last glacial recession and resulted in reduced allelic diversity and strong divergence of Lake Clarksockeye salmon relative to neighboring Six Mile Lake and LakeIliamna populations. Here we used two additional genetic marker types (allozymes and mtDNA) to examine these patterns further. Allozyme and mtDNA results were congruent with the microsatellite data in suggesting a common founder event in LakeClark sockeye salmon and confirmed the divergence of Lake Clarkpopulations from neighboring Six Mile Lake and Lake Iliamna populations. The use of multiple marker types provided better understanding of the bottleneck in Lake Clark. For example, the Sucker Bay Lake population had an exceptionally severe reduction in allelic diversity at microsatellite loci, but not at mtDNA. This suggests that the reduced microsatellite variation in Sucker Bay Lake fish is due to consistently smaller effective population size than other Lake Clark populations, rather than a more acute or additional bottleneck since founding. Caution is urged in using reduced heterozygosity as a measure of genetic bottleneck effects because stochastic variance among loci resulted in an overall increase in allozyme heterozygosity within bottlenecked Lake Clark populations. However, heterozygosity excess, which assesses heterozygosity relative to allelic variation, detected genetic bottleneck effects in both allozyme and microsatellite loci. 

Omitting chest tube drainage after thoracoscopic major lung resection.

PubMed

Ueda, Kazuhiro; Hayashi, Masataro; Tanaka, Toshiki; Hamano, Kimikazu

2013-08-01

Absorbable mesh and fibrin glue applied to prevent alveolar air leakage contribute to reducing the length of chest tube drainage, length of hospitalization and the rate of pulmonary complications. This study investigated the feasibility of omitting chest tube drainage in selected patients undergoing thoracoscopic major lung resection. Intraoperative air leakages were sealed with fibrin glue and absorbable mesh in patients undergoing thoracoscopic major lung resection. The chest tube was removed just after tracheal extubation if no air leakages were detected in a suction-induced air leakage test, which is an original technique to confirm pneumostasis. Patients with bleeding tendency or extensive thoracic adhesions were excluded. Chest tube drainage was omitted in 29 (58%) of 50 eligible patients and was used in 21 (42%) on the basis of suction-induced air leakage test results. Male gender and compromised pulmonary function were significantly associated with the failure to omit chest tube drainage (both, P < 0.05). Regardless of omitting the chest tube drainage, there were no adverse events during hospitalization, such as subcutaneous emphysema, pneumothorax, pleural effusion or haemothorax, requiring subsequent drainage. Furthermore, there was no prolonged air leakage in any patients: The mean length of chest tube drainage was only 0.9 days. Omitting the chest tube drainage was associated with reduced pain on the day of the operation (P = 0.046). The refined strategy for pneumostasis allowed the omission of chest tube drainage in the majority of patients undergoing thoracoscopic major lung resection without increasing the risk of adverse events, which may contribute to a fast-track surgery.

Fluctuations of Lake Eyre, South Australia

NASA Technical Reports Server (NTRS)

2002-01-01

Lake Eyre is a large salt lake situated between two deserts in one of Australia's driest regions. However, this low-lying lake attracts run-off from one of the largest inland drainage systems in the world. The drainage basin is very responsive to rainfall variations, and changes dramatically with Australia's inter-annual weather fluctuations. When Lake Eyre fills,as it did in 1989, it is temporarily Australia's largest lake, and becomes dense with birds, frogs and colorful plant life. The Lake responds to extended dry periods (often associated with El Nino events) by drying completely.

These four images from the Multi-angle Imaging SpectroRadiometer contrast the lake area at the start of the austral summers of 2000 and 2002. The top two panels portray the region as it appeared on December 9, 2000. Heavy rains in the first part of 2000 caused both the north and south sections of the lake to fill partially and the northern part of the lake still contained significant standing water by the time these data were acquired. The bottom panels were captured on November 29, 2002. Rainfall during 2002 was significantly below average ( http://www.bom.gov.au/ ), although showers occurring in the week before the image was acquired helped alleviate this condition slightly.

The left-hand panels portray the area as it appeared to MISR's vertical-viewing (nadir) camera, and are false-color views comprised of data from the near-infrared, green and blue channels. Here, wet and/or moist surfaces appear blue-green, since water selectively absorbs longer wavelengths such as near-infrared. The right-hand panels are multi-angle composites created with red band data from MISR's 60-degree forward, nadir and 60-degree backward-viewing cameras, displayed as red, green and blue, respectively. In these multi-angle composites, color variations serve as a proxy for changes in angular reflectance, and indicate textural properties of the surface related to roughness and/or moisture

Planetary Lake Lander - A Robotic Sentinel to Monitor a Remote Lake

NASA Technical Reports Server (NTRS)

Pedersen, Liam; Smith, Trey; Lee, Susan; Cabrol, Nathalie; Rose, Kevin

2012-01-01

The Planetary Lake Lander Project is studying the impact of rapid deglaciation at a high altitude alpine lake in the Andes, where disrupted environmental, physical, chemical, and biological cycles result in newly emerging natural patterns. The solar powered Lake Lander robot is designed to monitor the lake system and characterize both baseline characteristics and impacts of disturbance events such as storms and landslides. Lake Lander must use an onboard adaptive science-on-the-fly approach to return relevant data about these events to mission control without exceeding limited energy and bandwidth resources. Lake Lander carries weather sensors, cameras and a sonde that is winched up and down the water column to monitor temperature, dissolved oxygen, turbidity and other water quality parameters. Data from Lake Lander is returned via satellite and distributed to an international team of scientists via web-based ground data systems. Here, we describe the Lake Lander Project scientific goals, hardware design, ground data systems, and preliminary data from 2011. The adaptive science-on-the-fly system will be described in future papers.

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.

Downeast Drainage - Examining and Communicating the Dynamics of Bacteria Pollution Events in the Gulf of Maine

NASA Astrophysics Data System (ADS)

Smith, S. M.; Brady, D. C.; Cole, K. L.; Jones, S.; McGreavy, B.; Petersen, C.; Rothenheber, D.; Gerard, B.; Roy, S. G.

2015-12-01

The New England Sustainability Consortium is an interdisciplinary NSF EPSCoR funded project organized to strengthen the connections between science and decision-making and to advance the practice of sustainability science. The project uses complementary research capacity at several institutions to examine watershed and estuarine processes linked to bacteria pollution affecting shellfish harvesting and beach water quality in the Gulf of Maine. A fundamental research target is the development of a better approach for the prediction of coastal bacteria pollution events that can cause losses in tourism and shellfishery revenue. Enhanced prediction and communication of the events require a simultaneous examination of watershed pollution sources, drainage systems, estuarine residence times and bacterial survival. Our presentation will summarize initial observations from our investigations and stakeholder engagement activities at two project reference sites located in Wells and Bar Harbor, Maine. These will include field measurements, watershed and estuarine modeling outcomes, and stakeholder engagement results that are framed to quantify and explain land-sea interactions linked to bacterial pollution events in locations with varied relief, hydrodynamics, and stakeholder communities.

Influence of recent climatic events on the surface water storage of the Tonle Sap Lake.

PubMed

Frappart, F; Biancamaria, S; Normandin, C; Blarel, F; Bourrel, L; Aumont, M; Azemar, P; Vu, P-L; Le Toan, T; Lubac, B; Darrozes, J

2018-09-15

Lakes and reservoirs have been identified as sentinels of climate change. Tonle Sap is the largest lake in both the Mekong Basin and Southeast Asia and because of the importance of its ecosystem, it is has been described as the "heart of the lower Mekong". Its seasonal cycle depends on the annual flood pulse governed by the flow of the Mekong River. This study provides an impact analysis of recent climatic events from El Niño 1997/1998 to El Niño 2015/2016 on surface storage variations in the Tonle Sap watershed determined by combining remotely sensed observations, multispectral images and radar altimetry from 1993 to 2017. The Lake's surface water volume variations are highly correlated with rainy season rainfall in the whole Mekong River Basin (R = 0.84) at interannual time-scale. Extreme droughts and floods can be observed when precipitation deficit and excess is recorded in both the Tonle Sap watershed and the Mekong River Basin during moderate to very strong El Niño/La Niña events (R = -0.70) enhanced by the Pacific Decadal Oscillation (R = -0.68). Indian and Western North Pacific Monsoons were identified as having almost equal influence. Below normal vegetation activity was observed during the first semester of 2016 due to the extreme drought in 2015. Copyright © 2018 Elsevier B.V. All rights reserved.

Representing natural and manmade drainage systems in an earth system modeling framework

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

Li, Hongyi; Wu, Huan; Huang, Maoyi

Drainage systems can be categorized into natural or geomorphological drainage systems, agricultural drainage systems and urban drainage systems. They interact closely among themselves and with climate and human society, particularly under extreme climate and hydrological events such as floods. This editorial articulates the need to holistically understand and model drainage systems in the context of climate change and human influence, and discusses the requirements and examples of feasible approaches to representing natural and manmade drainage systems in an earth system modeling framework.

Glaciers, Glacial lakes and Glacial Lake Outburst Floods in the Koshi Basin

NASA Astrophysics Data System (ADS)

Shrestha, F.; Gao, X.; Khanal, N. R.; Maharjan, S. B.; Bajracharya, S. R.; Shrestha, R. B.; Lizong, W.; Mool, P. K.

2016-12-01

Glacier is a vital water resources for mountain communities. Recession in glacier area either increased the glacial lake size or develop a new lake. The consequences of these changes in lake has become one of the major issue in the management of GLOF risk. This paper presents the distribution of, and changes in, glaciers, glacial lakes in the Koshi basin and also looks at past GLOF events that have occurred in the basin and their distance of impact. Data on the number of glaciers and glacial lakes and their areas were generated for the years 1977, 1990, 2000, and 2010 using Landsat images. The study revealed that there were a total of 845 glaciers (Nepal side) and 2,168 glacial lakes (Nepal and China side) with a total area of 1,103 km2 and 127.608 km2 in 2010. The number of glacier increased by 15% (109) and area decreased by 26% (396 km2) over 33 years. In case of glacier lakes, the number and area increased from 1,160 to 2,168 and from 94.444 km2 to 127.608 km2 during 33 years with an overall growth rates of 86.9% and 35.1%. A large number of glacial lakes are small in size (≤ 0.1 km2). End moraine dammed lakes with area ≥ 0.1 km2 were selected to analyse the change characteristics of glacial lakes. The results show that there were 134 lakes ≥ 0.1 km2 in 2010; these lakes had a total area of 43.06 km2 in 1997, increased to 64.35 km2 in 2010. The distribution of lakes on the north side of the Himalayas (in China) was three times higher than on the south side of the Himalayas (in Nepal). Comparing the mean growth rate in area and length for the 33 years, the growth rate on the north side was found to be a little slower than that on the south side. This relationship did not hold true for length change in the different periods. The study identified 42 rapidly growing large lakes that are dangerous in terms of GLOF risk. In the past, 18 GLOF events have been reported. The downstream distance impacted by those events was up to 90 km. Among them, 13 GLOF events

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

Bacterial diversity and composition during rain events with and without Saharan dust influence reaching a high mountain lake in the Alps.

PubMed

Peter, Hannes; Hörtnagl, Paul; Reche, Isabel; Sommaruga, Ruben

2014-12-01

The diversity of airborne microorganisms that potentially reach aquatic ecosystems during rain events is poorly explored. Here, we used a culture-independent approach to characterize bacterial assemblages during rain events with and without Saharan dust influence arriving to a high mountain lake in the Austrian Alps. Bacterial assemblage composition differed significantly between samples with and without Saharan dust influence. Although alpha diversity indices were within the same range in both sample categories, rain events with Atlantic or continental origins were dominated by Betaproteobacteria, whereas those with Saharan dust intrusions were dominated by Gammaproteobacteria. The high diversity and evenness observed in all samples suggests that different sources of bacteria contributed to the airborne assemblage collected at the lake shore. During experiments with bacterial assemblages collected during rain events with Saharan dust influence, cell numbers rapidly increased in sterile lake water from initially ∼3 × 103 cell ml-1 to 3.6-11.1 x105 cells ml-1 within 4-5 days, and initially, rare taxa dominated at the end of the experiment. Our study documents the dispersal of viable bacteria associated to Saharan dust intrusions travelling northwards as far as 47° latitude.

Hydrological Modeling of Storm Water Drainage System due to Frequent and Intense Precipitation of Dhaka city using Storm Water Management Model (SWMM)

NASA Astrophysics Data System (ADS)

Hossain, S., Jr.

2015-12-01

Rainfall induced flooding during rainy season is a regular phenomenon in Dhaka City. Almost every year a significant part of the city suffers badly with drainage congestion. There are some highly dense areas with lower ground elevation which submerge under water even with an intense precipitation of few hours. The higher areas also suffer with the drainage problem due to inadequate maintenance of the system and encroachment or illegal filling up of the drainage canals and lakes. Most part of the city suffered from long term urban flooding during historical extreme rainfall events in September 2004, 2007 and July 2009. The situation is likely to worsen in the future due to Climate Change, which may lead to more frequent and intense precipitation. To assess the major and minor drainage systems and elements of the urban basins using the hydrodynamic modelling and, through this, identifying the flooding events and areas, taking into account the current situation and future flood or drainage scenarios. Stormwater modeling has a major role in preventing issues such as flash floods and urban water-quality problems. Stormwater models of a lowered spatial resolution would thus appear valuable if only their ability to provide realistic results could be proved. The present scenario of urban morphology of Dhaka city and existing drainage system is complex for hydrological and hydrodynamic modeling. Furthermore limitations of background data and uncertain future urban scenarios may confine the potential outputs of a model. Although several studies were carried out including modeling for drainage master planning, a detail model for whole DAP (Detaile Area Plan) of Dhaka city area is not available. The model developed under this study is covering the existing drainage system in the study area as well as natural flows in the fringe area. A good number of models are available for hydrological and hydraulic analysis of urban areas. These are MIKE 11, MOUSE, HEC-RAS, HEC HMS and EPA

Surface runoff and tile drainage transport of phosphorus in the midwestern United States.

PubMed

Smith, Douglas R; King, Kevin W; Johnson, Laura; Francesconi, Wendy; Richards, Pete; Baker, Dave; Sharpley, Andrew N

2015-03-01

The midwestern United States offers some of the most productive agricultural soils in the world. Given the cool humid climate, much of the region would not be able to support agriculture without subsurface (tile) drainage because high water tables may damage crops and prevent machinery usage in fields at critical times. Although drainage is designed to remove excess soil water as quickly as possible, it can also rapidly transport agrochemicals, including phosphorus (P). This paper illustrates the potential importance of tile drainage for P transport throughout the midwestern United States. Surface runoff and tile drainage from fields in the St. Joseph River Watershed in northeastern Indiana have been monitored since 2008. Although the traditional concept of tile drainage has been that it slowly removes soil matrix flow, peak tile discharge occurred at the same time as peak surface runoff, which demonstrates a strong surface connection through macropore flow. On our research fields, 49% of soluble P and 48% of total P losses occurred via tile discharge. Edge-of-field soluble P and total P areal loads often exceeded watershed-scale areal loadings from the Maumee River, the primary source of nutrients to the western basin of Lake Erie, where algal blooms have been a pervasive problem for the last 10 yr. As farmers, researchers, and policymakers search for treatments to reduce P loading to surface waters, the present work demonstrates that treating only surface runoff may not be sufficient to reach the goal of 41% reduction in P loading for the Lake Erie Basin. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Contemporary suspended sediment dynamics within two partly glacierized mountain drainage basins in western Norway (Erdalen and Bødalen, inner Nordfjord)

NASA Astrophysics Data System (ADS)

Beylich, Achim A.; Laute, Katja; Storms, Joep E. A.

2017-06-01

This paper focuses on environmental controls, spatiotemporal variability and rates of contemporary fluvial suspended sediment transport in the neighboring, partly glacierized and steep Erdalen (79.5 km2) and Bødalen (60.1 km2) drainage basins in the fjord landscape of the inner Nordfjord in western Norway. Field work, including extended samplings and measurements, was conducted since 2004 in Erdalen and since 2008 in Bødalen. The distinct intra- and inter-annual temporal variability of suspended sediment transport found is mostly controlled by meteorological events, with most suspended sediment transport occurring during pluvial events in autumn (September-November), followed by mostly thermally determined glacier melt in summer (July-August), and by mostly thermally determined snowmelt in spring (April-June). Extreme rainfall events (> 70 mm d- 1) in autumn can trigger significant debris-flow activity that can cause significant transfers of suspended sediments from ice-free surface areas with sedimentary covers into main stream channels and is particularly important for fluvial suspended sediment transport. In years with occurring relevant debris-flow activity the total annual drainage-basin wide suspended sediment yields are strongly determined by these single extreme events. The proportion of glacier coverage, followed by steepness of slopes, and degree of vegetation cover in ice-free surface areas with sedimentary covers are the main controls for the detected spatial variability of suspended sediment yields. The contemporary sediment supply from glacierized surface areas and the Jostedalsbreen ice cap through different defined outlet glaciers shows a high spatial variability. The fact that the mean annual suspended sediment yield of Bødalen is with 31.3 t km- 2 yr- 1 almost twice as high as the mean annual suspended sediment yield of Erdalen (16.4 t km- 2 yr- 1) is to a large extent explained by the higher proportion of glacier coverage in Bødalen (38% of

Water quality of Fremont Lake and New Fork Lakes, western Wyoming; a progress report

USGS Publications Warehouse

Peterson, D.A.; Averett, R.C.; Mora, K.L.

1987-01-01

Fremont Lake and New Fork Lakes in the New Fork River drainage of western Wyoming were selected for a comprehensive study of hydrologic processes affecting mountain lakes in the Rocky Mountains. Information is needed about lakes in this area to assess their response to existing and planned development. The concerns include regional issues such as acid precipitation from gas-sweetening plants, coal-fired powerplants, and smelters, as well as local issues, such as shoreline development and raising outlet control structures. Onsite measurements indicated strong thermal stratification in the lakes during the summer. Isothermal conditions occurred during December 1983 and May 1984. Mean phytoplankton concentrations were less than 5,000 cells/ml, and chlorophyll a concentrations were weakly correlated with phytoplankton concentrations. Zooplankton concentrations were small, less than 6 organisms/L. The numbers of benthic invertebrates/unit area in Fremont Lake were extremely small. The lake waters and inflow and outflow streams were chemically dilute solutions. Mean dissolved-solids concentrations were 13 mg/L in Fremont Lake and 24 mg/L in New Fork Lakes. Calcium and bicarbonate were the predominant ions. Concentrations of phosphorus and nitrogen usually were less than detection limits. Trace-metals concentrations in the lakes were similar to those in precipitation and generally were small. Dissolved organic-carbon concentrations were about 1 mg/L. Concentrations of fulvic and humic acids were relatively large in the inlet of Fremont Lake during the spring. Pine Creek has deposited 800 metric tons of sediment, on an annual average, to the delta of Fremont Lake. Most sediment is deposited during spring runoff. (USGS)

Hydrology of Lake Butler, Orange County, Florida

USGS Publications Warehouse

Smoot, James L.; Schiffer, Donna M.

1984-01-01

Lake Butler is one of the lakes that collectively make up the Butler chain of lakes in the headwaters of the Kissimmee River, Florida. The bottom configuration of the lake is typical of relict karst features formed during lower stages in sea level. The top of the Floridan aquifer is 50 to 100 feet below the land surface. The drainage area of Lake Butler is approximately 14.5 sq mi and is comprised of sub-basins of other lakes in the vicinity. Surface outflow from Lake Butler is generally southward to Cypress Creek, a tributary of the Kissimmee River. The extremes in lake stage for the period 1933-81 are 94.67 ft on June 23, 1981 and 101.78 ft on September 13, 1960. The median lake stage for this period was 99.28 ft above sea level. The quality of water in Lake Butler is excellent, based on studies of physical, chemical, and biological conditions by the Orange County Pollution Control Department. The lake water is slightly acidic and soft (48 mg/L hardness as calcium carbonate). Pesticides in water were below detection levels at two sites sampled in the lake, but were detected in the bottom sediments. (USGS)

Glacial lake inventory and lake outburst potential in Uzbekistan.

PubMed

Petrov, Maxim A; Sabitov, Timur Y; Tomashevskaya, Irina G; Glazirin, Gleb E; Chernomorets, Sergey S; Savernyuk, Elena A; Tutubalina, Olga V; Petrakov, Dmitriy A; Sokolov, Leonid S; Dokukin, Mikhail D; Mountrakis, Giorgos; Ruiz-Villanueva, Virginia; Stoffel, Markus

2017-08-15

Climate change has been shown to increase the number of mountain lakes across various mountain ranges in the World. In Central Asia, and in particular on the territory of Uzbekistan, a detailed assessment of glacier lakes and their evolution over time is, however lacking. For this reason we created the first detailed inventory of mountain lakes of Uzbekistan based on recent (2002-2014) satellite observations using WorldView-2, SPOT5, and IKONOS imagery with a spatial resolution from 2 to 10m. This record was complemented with data from field studies of the last 50years. The previous data were mostly in the form of inventories of lakes, available in Soviet archives, and primarily included localized in-situ data. The inventory of mountain lakes presented here, by contrast, includes an overview of all lakes of the territory of Uzbekistan. Lakes were considered if they were located at altitudes above 1500m and if lakes had an area exceeding 100m 2 . As in other mountain regions of the World, the ongoing increase of air temperatures has led to an increase in lake number and area. Moreover, the frequency and overall number of lake outburst events have been on the rise as well. Therefore, we also present the first outburst assessment with an updated version of well-known approaches considering local climate features and event histories. As a result, out of the 242 lakes identified on the territory of Uzbekistan, 15% are considered prone to outburst, 10% of these lakes have been assigned low outburst potential and the remainder of the lakes have an average level of outburst potential. We conclude that the distribution of lakes by elevation shows a significant influence on lake area and hazard potential. No significant differences, by contrast, exist between the distribution of lake area, outburst potential, and lake location with respect to glaciers by regions. Copyright © 2017 Elsevier B.V. All rights reserved.

Future volcanic lake research: revealing secrets from poorly studied lakes

NASA Astrophysics Data System (ADS)

Rouwet, D.; Tassi, F.; Mora-Amador, R. A.

2012-04-01

Volcanic lake research boosted after the 1986 Lake Nyos lethal gas burst, a limnic rather than volcanic event. This led to the formation of the IAVCEI-Commission on Volcanic Lakes, which grew out into a multi-disciplinary scientific community since the 1990's. At Lake Nyos, a degassing pipe is functional since 2001, and two additional pipes were added in 2011, aimed to prevent further limnic eruption events. There are between 150 and 200 volcanic lakes on Earth. Some acidic crater lakes topping active magmatic-hydrothermal systems are monitored continuously or discontinuously. Such detailed studies have shown their usefulness in volcanic surveillance (e.g. Ruapehu, Yugama-Kusatsu-Shiran, Poás). Others are "Nyos-type" lakes, with possible gas accumulation in bottom waters and thus potentially hazardous. "Nyos-type" lakes tend to remain stably stratified in tropical and sub-tropical climates (meromictic), leading to long-term gas build-up and thus higher potential risk. In temperate climates, such lakes tend to turn over in winter (monomictic), and thus liberating its gas charge yearly. We line out research strategies for the different types of lakes. We believe a complementary, multi-disciplinary approach (geochemistry, geophysics, limnology, biology, statistics, etc.) will lead to new insights and ideas, which can be the base for future following-up and monitoring. After 25 years of pioneering studies on rather few lakes, the scientific community should be challenged to study the many poorly studied volcanic lakes, in order to better constrain the related hazard, based on probabilistic approaches.

[First flush effects of storm events of Baoxiang River in Lake Dianchi Watershed].

PubMed

Guo, Huai-Cheng; Xiang, Nan; Zhou, Feng; Wang, Yong-Hua; Li, Fa-Rong; Zhu, Xiang; Mao, Guo-Zhu; Yu, Shu-Xia; Li, Na; Sheng, Hu; Yang, Yong-Hui; He, Cheng-Jie; Wang, Cui-Yu

2013-04-01

To understand riverine process of non-point source effectively, first flush effects of storm events were investigated at Baoxiang River of Lake Dianchi Watershed. Three sampling stations were selected along Baoxiang River for observing the flow rate and pollutant concentrations of the first three storm events from June 2009 to August 2009. Net discharged volume, net discharged loading, and net event mean concentration (EMC(n)) were proposed with their calculation methods. According to the analysis of three storm events at three stations, the following results colcd be extracted: (1) the larger the percent of impervious land and population density were, the higher EMC(n) of TSS, TN, TP, permanganate index and their cumulative curves [M(V)] were along the river; (2) TSS, TP loadings as well as their M (V) were positively correlated to the storm intensity, while TN and permanganate index loadings were consistent with the total rainfall of each storm event, where the percent of NO3(-) -N in total nitrogen decreased gradually when the number of storm events increased; (3) compared to tradition EMC, EMC(n) was proven to be a better indicator to accurately uncover and magnify the differences in first flush effects of storm events among different stations or storm events.

Response in the trophic state of stratified lakes to changes in hydrology and water level: potential effects of climate change

USGS Publications Warehouse

Robertson, Dale M.; Rose, William J.

2011-01-01

To determine how climate-induced changes in hydrology and water level may affect the trophic state (productivity) of stratified lakes, two relatively pristine dimictic temperate lakes in Wisconsin, USA, were examined. Both are closed-basin lakes that experience changes in water level and degradation in water quality during periods of high water. One, a seepage lake with no inlets or outlets, has a small drainage basin and hydrology dominated by precipitation and groundwater exchange causing small changes in water and phosphorus (P) loading, which resulted in small changes in water level, P concentrations, and productivity. The other, a terminal lake with inlets but no outlets, has a large drainage basin and hydrology dominated by runoff causing large changes in water and P loading, which resulted in large changes in water level, P concentrations, and productivity. Eutrophication models accurately predicted the effects of changes in hydrology, P loading, and water level on their trophic state. If climate changes, larger changes in hydrology and water levels than previously observed could occur. If this causes increased water and P loading, stratified (dimictic and monomictic) lakes are expected to experience higher water levels and become more eutrophic, especially those with large developed drainage basins.

Total Phosphorus Loads for Selected Tributaries to Sebago Lake, Maine

USGS Publications Warehouse

Hodgkins, Glenn A.

2001-01-01

The streamflow and water-quality datacollection networks of the Portland Water District (PWD) and the U.S. Geological Survey (USGS) as of February 2000 were analyzed in terms of their applicability for estimating total phosphorus loads for selected tributaries to Sebago Lake in southern Maine. The long-term unit-area mean annual flows for the Songo River and for small, ungaged tributaries are similar to the long-term unit-area mean annual flows for the Crooked River and other gaged tributaries to Sebago Lake, based on a regression equation that estimates mean annual streamflows in Maine. Unit-area peak streamflows of Sebago Lake tributaries can be quite different, based on a regression equation that estimates peak streamflows for Maine. Crooked River had a statistically significant positive relation (Kendall's Tau test, p=0.0004) between streamflow and total phosphorus concentration. Panther Run had a statistically significant negative relation (p=0.0015). Significant positive relations may indicate contributions from nonpoint sources or sediment resuspension, whereas significant negative relations may indicate dilution of point sources. Total phosphorus concentrations were significantly larger in the Crooked River than in the Songo River (Wilcoxon rank-sum test, p<0.0001). Evidence was insufficient, however, to indicate that phosphorus concentrations from medium-sized drainage basins, at a significance level of 0.05, were different from each other or that concentrations in small-sized drainage basins were different from each other (Kruskal-Wallis test, p= 0.0980, 0.1265). All large- and medium-sized drainage basins were sampled for total phosphorus approximately monthly. Although not all small drainage basins were sampled, they may be well represented by the small drainage basins that were sampled. If the tributaries gaged by PWD had adequate streamflow data, the current PWD tributary monitoring program would probably produce total phosphorus loading data that

Widespread Lake Highstands in the Southernmost Andean Altiplano during Heinrich Event 1: Implications for the South American Summer Monsoon

NASA Astrophysics Data System (ADS)

Chen, C. Y.; McGee, D.; Quade, J.

2014-12-01

Speleothem-based oxygen isotope records provide strong evidence of anti-phased behavior of the northern and southern hemisphere summer monsoons during Heinrich events, but we lack rigorous constraints on the amount of wetting or drying occurring in monsoon regions. Studies centered on shoreline deposits of closed-basin lakes are well suited for establishing such quantitative controls on water balance changes by providing unequivocal evidence of lake volume variations. Here we present new dating constraints on the highstands of several high-altitude (3800-4350 m) paleolakes in the southern Andean Altiplano, an outlying arid region of the Atacama Desert stretching across the Chilean-Bolivian-Argentinian border east of the Andes (20-25°S). These lakes once occupied the closed basins where only phreatic playas, dry salars, and shallow ponds exist today. Initial U-Th dating of massive shoreline tufas reveals that these deposits are dateable to within ±150 to 300 yrs due to high U concentrations and low initial Th content (as indicated by high 230Th/232Th). Our U-Th and 14C dates show that lake highstands predominantly occur between 18.5 and 14.5 kyrs BP, coinciding with Heinrich Event 1 (HE1) and the expansion of other nearby lakes, such as Lake Titicaca. Because of their (1) location at the modern-day southwestern edge of the summer monsoon, (2) intact shoreline preservation, and (3) precise age control, these lakes may uniquely enable us to reconstruct the evolution of water balance (P-E) changes associated with HE1. Hydrologic modeling constrained by temperature estimates provided by local glacial records is used to provide bounds for past precipitation changes. We also examine North Atlantic cooling as the mechanism for these changes by comparing a compilation of S. American lake level records with various hosing experiments and transient climate simulations at HE1. Our results lend us confidence in expanding our U-Th work to other shoreline tufas in the

Cooper Creek/Lake Yamma Yamma as seen from STS-67 Endeavour

NASA Technical Reports Server (NTRS)

1995-01-01

Cooper Creek is one of the largest drainage's in the Channel Country of the arid interior of Australia (Queensland). Rivers in this region are usually dry but during floods (a few times per century) they occupy very wide flood plains, shown here as the darker areas with hairlike rills. After the great rains which recently fell in many parts of Australia, individual rills contain water and show up in sunglint in this view. Flow is to the south (top) towards Lake Eyre. Lake Yamma Yamma is the medallion-shaped 'flood-out' lake right center. Water can be seen entering the lake.

Effects of dissolved organic matter leaching from macrophyte litter on black water events in shallow lakes.

PubMed

He, Yuhong; Song, Na; Jiang, He-Long

2018-04-01

In recent years, the black water phenomenon has become an environmental event in eutrophic shallow lakes in China, leading to deterioration of lake ecosystems and potable water crises. Decomposition of macrophyte debris has been verified as a key inducement for black water events. In this study, the effects of the decomposition of dissolved organic matter (Kottelat et al., WASP 187:343-351, 2008) derived from macrophyte leachate on the occurrence of black water events are investigated to clarify the detailed mechanisms involved. Results show that dissolved organic matter (DOM) is composed of a trace of chromophoric DOM and mostly non-chromophoric dissolved organic matter (CDOM). DOM decomposition is accompanied by varied concentration of CDOM components, generation of organic particles, and increased microbial concentrations. These processes increase water chroma only during initial 48 h, so the intensified water color cannot be maintained by DOM decomposition alone. During DOM decomposition, microorganisms first consume non-CDOM, increasing the relative CDOM concentration and turning the water color to black (or brown). Simultaneously, tryptophan and aromatic proteins, which are major ingredients of CDOM, enhance UV light absorption, further aggravating the macroscopic phenomenon of black color. Our results show that DOM leached from decayed macrophytes promotes or even triggers the occurrence of black water events and should be taken more seriously in the future.

Multi-Scale Simulations of Past and Future Projections of Hydrology in Lake Tahoe Basin, California-Nevada (Invited)

NASA Astrophysics Data System (ADS)

Niswonger, R. G.; Huntington, J. L.; Dettinger, M. D.; Rajagopal, S.; Gardner, M.; Morton, C. G.; Reeves, D. M.; Pohll, G. M.

2013-12-01

Water resources in the Tahoe basin are susceptible to long-term climate change and extreme events because it is a middle-altitude, snow-dominated basin that experiences large inter-annual climate variations. Lake Tahoe provides critical water supply for its basin and downstream populations, but changes in water supply are obscured by complex climatic and hydrologic gradients across the high relief, geologically complex basin. An integrated surface and groundwater model of the Lake Tahoe basin has been developed using GSFLOW to assess the effects of climate change and extreme events on surface and groundwater resources. Key hydrologic mechanisms are identified with this model that explains recent changes in water resources of the region. Critical vulnerabilities of regional water-supplies and hazards also were explored. Maintaining a balance between (a) accurate representation of spatial features (e.g., geology, streams, and topography) and hydrologic response (i.e., groundwater, stream, lake, and wetland flows and storages), and (b) computational efficiency, is a necessity for the desired model applications. Potential climatic influences on water resources are analyzed here in simulations of long-term water-availability and flood responses to selected 100-year climate-model projections. GSFLOW is also used to simulate a scenario depicting an especially extreme storm event that was constructed from a combination of two historical atmospheric-river storm events as part of the USGS MultiHazards Demonstration Project. Historical simulated groundwater levels, streamflow, wetlands, and lake levels compare well with measured values for a 30-year historical simulation period. Results are consistent for both small and large model grid cell sizes, due to the model's ability to represent water table altitude, streams, and other hydrologic features at the sub-grid scale. Simulated hydrologic responses are affected by climate change, where less groundwater resources will be

Early Holocene change in atmospheric circulation in the Northern great plains: An upstream view of the 8.2 ka cold event

USGS Publications Warehouse

Dean, W.E.; Forester, R.M.; Bradbury, J.P.

2002-01-01

Elk Lake, in northwestern Minnesota, contains numerous proxy records of climatic and environmental change contained in varved sediments with annual resolution for the last 10,000 years. These proxies show that about 8200 calendar years ago (8.2 cal. ka; 7300 radiocarbon years) Elk Lake went from a well-stratified lake that was wind-protected in a boreal forest to a well-mixed lake in open prairie savanna receiving northwesterly wind-blown dust, probably from the dry floor of Lake Agassiz. This change in climate marks the initiation of the widely recognized mid-Holocene "altithermal" in central North America. The coincidence of this change with the so-called 8.2 cal. ka cold event, recognized in ice-core and other records from the circum-North Atlantic, and thought by some to be caused by catastrophic discharge of freshwater from proglacial lakes Agassiz and Ojibway, suggests that the two "events" might be related. Our interpretation of the Elk Lake proxy records, and of other records from less accurately dated sites, suggests that change in climate over North America was the result of a fundamental change in atmospheric circulation in response to marked changes in the relative proportions of land, water, and, especially, glacial ice in North America during the early Holocene. This change in circulation probably post-dates the final drainage of proglacial lakes along the southern margin of the Laurentide ice sheet, and may have produced a minor perturbation in climate over Greenland that resulted in a brief cold pulse detected in ice cores. ?? 2002 Elsevier Science Ltd. All rights reserved.

78 FR 36424 - Special Local Regulations for Summer Events; Captain of the Port Lake Michigan Zone

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-18

... Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing temporary special local regulations for three summer events within the Captain of the Port Lake Michigan Zone. This rule is intended to provide for the safety of life and property on navigable waters immediately prior to...

Lake Sarez, Tajikistan

NASA Technical Reports Server (NTRS)

2002-01-01

Lake Sarez (top), deep in the Pamir mountains of Tajikistan, was created 90 years ago when a strong earthquake triggered a massive landslide that, in turn, became a huge dam along the Murghob River, now called the Usoi Dam. The resulting lake is perched above surrounding drainages at an elevation greater than 3000m, and is part of the watershed that drains the towering Akademi Nauk Range (see the regional image, lower). The lake is 61 km long and as deep as 500 m, and holds an estimated 17 cubic km of water. The area experiences considerable seismic activity, and scientists fear that part of the right bank may slump into the lake, creating a huge wave that will top over and possibly breach the natural dam. Such a wave would create a catastrophic flood downstream along the Bartang, Panj and Amu Darya Rivers, perhaps reaching all the way to the Aral Sea. Currently, central Asian governments, as well as the World Bank and the UN are monitoring the dam closely, and have proposed gradually lowering the lake level as a preventive measure. More information about the lake is available at the following web sites: Lake Sarez Study group, UN Report, Reliefweb Digital photograph numbers ISS002-E-7771 and ISS002-E-7479 were taken in the spring of 2001 from Space Station Alpha and are provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

Priority Scale of Drainage Rehabilitation of Cilacap City

NASA Astrophysics Data System (ADS)

Rudiono, Jatmiko

2018-03-01

Characteristics of physical condition of Cilacap City is relatively flat and low to sea level (approximately 6 m above sea level). In the event of a relatively heavy rainfall resulting in inundation at several locations. The problem of inundation is a serious problem if there is in a dense residential area or occurs in publicly-used infrastructure, such as roads and settlements. These problems require improved management of which include how to plan a sustainable urban drainage system and environmentally friendly. The development of Cilacap City is increasing rapidly, this causes drainage system based on the Drainage Masterplan Cilacap made in 2006 has not been able to accommodate rain water, so, it is necessary to evaluate the drainage masterplan for subsequent rehabilitation. Priority scale rehabilitation of the drainage sections as a guideline is an urgent need of rehabilitation in the next time period.

New SIMS U-Pb age constraints on the largest lake transgression event in the Songliao Basin, NE China.

PubMed

Xi, Dangpeng; He, Huaiyu; Yu, Zhiqiang; Huang, Qinghua; Hu, Jianfang; Xu, Yankang; Shi, Zhongye; Qin, Zuohuan; Wan, Xiaoqiao

2018-01-01

The largest lake transgression event (LTE) associated with lake anoxic events (LAE) and periodic seawater incursion events (SWIE) in the Songliao Basin, northeastern China, occurred during deposition of the Cretaceous Nenjiang Formation. The Yaojia-Nenjiang Formation boundary (YNB) marks the beginning of the LTE, as well as LAE and SWIE. However, there is an absence of direct radioisotopic dating, and therefore the age of the YNB, as well as the beginning of LTE, together with their relationship with other geological events, is strongly debated. Here we present a new SIMS U-Pb zircon age from the lowermost Nenjiang Formation. The bentonite bed located 9.88 m above the YNB of the X1-4 borehole was analyzed. Twenty-five analyses of 25 zircons were conducted, which produced a weighted mean age of 85.5±0.6 Ma (MSWD = 0.87). Based on the average sediment accumulation rate, the age of the YNB is suggested to be 85.7 Ma, indicating that the LTE began in the Early Santonian. The new ages provide a precise chronostratigraphic framework for climatic and geological events. Our new results imply that the beginning of the LTE, LAE and SWIE occurred almost simultaneously with short-term sea level rise, and probably had a close relationship with OAE3.

Water-quality and sediment-chemistry data of drain water and evaporation ponds from Tulare Lake Drainage District, Kings County, California March 1985 to March 1986

USGS Publications Warehouse

Fujii, Roger

1988-01-01

Trace element and major ion concentrations were measured in water samples collected monthly between March 1985 and March 1986 at the MD-1 pumping station at the Tulare Lake Drainage District evaporation ponds, Kings County, California. Samples were analyzed for selected pesticides several times during the year. Salinity, as measured by specific conductance, ranged from 11,500 to 37,600 microsiemens/centimeter; total recoverable boron ranged from 4,000 to 16,000 micrg/L; and total recoverable molybdenum ranged from 630 to 2,600 microg/L. Median concentrations of total arsenic and total selenium were 97 and 2 microg/L. Atrazine, prometone, propazine, and simazine were the only pesticides detected in water samples collected at the MD-1 pumping station. Major ions, trace elements, and selected pesticides also were analyzed in water and bottom-sediment samples from five of the southern evaporation ponds at Tulare Lake Drainage District. Water enters the ponds from the MD-1 pumping station at pond 1 and flows through the system terminating at pond 10. The water samples increased in specific conductance (21,700 to 90,200 microsiemens/centimeter) and concentrations of total arsenic (110 to 420 microg/L), total recoverable boron (12,000 to 80,000 microg/L) and total recoverable molybdenum (1,200 to 5,500 microg/L) going from pond 1 to pond 10, respectively. Pesticides were not detected in water from any of the ponds sampled. Median concentrations of total arsenic and total selenium in the bottom sediments were 4.0 and 0.9 microg/g, respectively. The only pesticides detected in bottom sediment samples from the evaporation ponds were DDD and DDE, with maximum concentration of 0.8 microg/kilogram. (Author 's abstract)

Delineation of a Re-establishing Drainage Network Using SPOT and Landsat Images

NASA Astrophysics Data System (ADS)

Bailey, J. E.; Self, S.; Mouginis-Mark, P. J.

2008-12-01

The 1991 eruption of Mt. Pinatubo, The Philippines, provided a unique opportunity to study the effects on the landscape of a large eruption in part because it took place after the advent of regular satellite-based observations. The eruption formed one large (>100km2) ignimbrite sheet, with over 70% of the total deposit deposited in three primary drainage basins to the west of the volcano. High-resolution (20 m/pixel) satellite images, showing the western drainage basins and surrounding region both before and after the eruption were used to observe the re-establishment and evolution of drainage networks on the newly emplaced ignimbrite sheet. Changes in the drainage networks were delineated from a time series of SPOT (Satellite Pour l'Observation de la Terre) and Landsat multi-spectral satellite images. The analysis of which was supplemented by ground- based observations. The satellite images showed that the blue prints for the new drainage systems were established early (within days of the eruption) and at a large-scale followed the pre-eruption pattern. However, the images also illustrated the ephemeral nature of many channels due to the influence of secondary pyroclastic flows, lahar- dammed lake breakouts, stream piracy and shifts due to erosion. Characteristics of the defined drainage networks were used to infer the relative influence on the lahar hazard within each drainage basin.

Pesticide leaching by agricultural drainage in sloping, mid-textured soil conditions - the role of runoff components.

PubMed

Zajíček, Antonín; Fučík, Petr; Kaplická, Markéta; Liška, Marek; Maxová, Jana; Dobiáš, Jakub

2018-04-01

Dynamics of pesticides and their metabolites in drainage waters during baseflow periods and rainfall-runoff events (RREs) were studied from 2014 to 2016 at three small, tile-drained agricultural catchments in Bohemian-Moravian Highlands, Czech Republic. Drainage systems in this region are typically built in slopes with considerable proportion of drainage runoff originating outside the drained area itself. Continuous monitoring was performed by automated samplers, and the event hydrograph was separated using 18 O and 2 H isotopes and drainage water temperature. Results showed that drainage systems represent a significant source for pesticides leaching from agricultural land. Leaching of pesticide metabolites was mainly associated with baseflow and shallow interflow. Water from causal precipitation diluted their concentrations. The prerequisites for the leaching of parental compounds were a rainfall-runoff event occurring shortly after spraying, and the presence of event water in the runoff. When such situations happened consequently, pesticides concentrations in drainage water were high and the pesticide load reached several grams in a few hours. Presented results introduce new insights into the processes of pesticides movement in small, tile-drained catchments and emphasizes the need to incorporate drainage hydrology and flow-triggered sampling into monitoring programmes in larger catchments as well as in environment-conservation policy.

A Killer Lake

ERIC Educational Resources Information Center

Horvath, Thomas

2005-01-01

In 1986, Lake Nyos, a volcanic lake in Cameroon, released a huge amount of carbon dioxide gas, killing over 1,700 people in the surrounding area. This case study, developed for use in a limnology or aquatic biology course, explores that event, introducing students to concepts relating to lake formation, thermal stratification, and dissolved gases.…

Three-Dimensional Simulation of Avalanche-Generated Impulse Waves and Evaluation of Lake-Lowering Scenarios at Lake Palcacocha, Peru

NASA Astrophysics Data System (ADS)

Chisolm, R. E.; McKinney, D. C.

2014-12-01

Accelerated retreat of Andean glaciers in recent decades due to a warming climate has caused the emergence and growth of glacial lakes. As these lakes continue to grow, they pose an increasing risk of glacial lake outburst floods (GLOFs). GLOFs can be triggered by moraine failures or by avalanches, rockslides, or ice calving into glacial lakes. For many decades Lake Palcacocha in the Cordillera Blanca, Peru has threatened citizens living in the city of Huaraz which was devastated by a GLOF in 1941. A safety system for Lake Palcacocha was put in place in the 1970's to control the lake level, but the lake has since grown to the point where it is once again dangerous. Overhanging ice from the glaciers above and a relatively low freeboard make the lake vulnerable to avalanches and landslides. Lake Palcacocha is used as a case study to investigate the impact of an avalanche event on the lake dynamics. Three-dimensional lake modeling in the context of glacial hazards is not common, but 3D simulations can enhance our understanding of avalanche-generated impulse waves and their downstream impacts. In this work, a 3D hydrodynamic model is used to simulate the generation of an impulse wave from an avalanche falling into the lake, wave propagation, and overtopping of the terminal moraine. These results are used as inputs to a downstream model to predict the impact from a GLOF. As lowering the level of the lake is the most likely mitigation alternative, several scenarios are considered to evaluate the impact from avalanche events with a reduction in the lake level. The results of this work can be used to evaluate the effectiveness of the current lake management system and potential lake-lowering alternatives. Use of a robust 3D lake model enables more accurate predictions of peak flows during GLOF events and the time scales of these events so that mitigation strategies can be developed that reduce the risk to communities living downstream of hazardous lakes.

Abrupt drainage cycles of the Fennoscandian Ice Sheet.

PubMed

Soulet, Guillaume; Ménot, Guillemette; Bayon, Germain; Rostek, Frauke; Ponzevera, Emmanuel; Toucanne, Samuel; Lericolais, Gilles; Bard, Edouard

2013-04-23

Continental ice sheets are a key component of the Earth's climate system, but their internal dynamics need to be further studied. Since the last deglaciation, the northern Eurasian Fennoscandian Ice Sheet (FIS) has been connected to the Black Sea (BS) watershed, making this basin a suitable location to investigate former ice-sheet dynamics. Here, from a core retrieved in the BS, we combine the use of neodymium isotopes, high-resolution elemental analysis, and biomarkers to trace changes in sediment provenance and river runoff. We reveal cyclic releases of meltwater originating from Lake Disna, a proglacial lake linked to the FIS during Heinrich Stadial 1. Regional interactions within the climate-lake-FIS system, linked to changes in the availability of subglacial water, led to abrupt drainage cycles of the FIS into the BS watershed. This phenomenon raised the BS water level by ∼100 m until the sill of the Bosphorus Strait was reached, flooding the vast northwestern BS shelf and deeply affecting the hydrology and circulation of the BS and, probably, of the Marmara and Aegean Seas.

Tonle Sap Lake Water Storage Change Over 24 Years From Satellite Observation and Its Link With Mekong River Discharge and Climate Events

NASA Astrophysics Data System (ADS)

Biancamaria, S.; Frappart, F.; Normandin, C.; Blarel, F.; Bourrel, L.; Aumont, M.; Azema, P.; Vu, P. L.; Lubac, B.; Darrozes, J.

2017-12-01

The Tonle Sap lake is the largest freshwater lake in Southeast Asia and is located within the Mekong basin (mainly in Cambodia). It is one of he most productive ecosystem of the world and provide two thirds of Cambodia fish catch. It also plays a unique role on the Mekong basin hydrological cycle: during the monsoon period, the Mekong river partially flows to the lake, whereas during the dry season, the lake flows to the Mekong delta. It is therefore crucial to monitor and take into account this lake to estimate Mekong discharge to the ocean. However, in situ measurements of lake level and river discharge are very sparse (especially during the last decades) and computing lake storage variation from in situ data only is difficult due to the huge annual variation of lake area. That's why, satellite data (nadir radar altimetry and visible imagery) have been used to study its volume variation and its relationship with climate events and Mekong river discharge. Multi-mission altimetry data have been extracted (Topex, ERS-2, ENVISAT, Jason-1, Jason-2, Saral and Jason-3, using CTOH data extraction tools) to derive a lake water level from1993 to 2016, which varies from 3 m to 12 m. Lake area have been computed from MODIS data from 2000 to 2016 and varies from 3,400 km2 to 11,800 km2. These dataset clearly shows a relationship between lake water level and area, which has been used to estimate lake water volume change from 1995 to 2016, with a minimum in 2015 and a maximum in 2011. Lake's droughts and floods can be observed during moderate and strong El Nino/La Nina events, enhanced by the Pacific Decadal Oscillation. Besides, comparison with in situ discharge at the outlet of the Mekong basin (over 1995/2000 time period) shows that lake water level is 20 days time lagged and increases/decreases after Mekong discharge at its outlet. This time lag results of Mekong river partially flowing to the lake. Finally, high correlation between lake level and outlet discharge allows to

75 FR 34934 - Safety Zone; Fireworks for the Virginia Lake Festival, Buggs Island Lake, Clarksville, VA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-21

...-AA00 Safety Zone; Fireworks for the Virginia Lake Festival, Buggs Island Lake, Clarksville, VA AGENCY... Fireworks for the Virginia Lake Festival event. This action is intended to restrict vessel traffic movement... Virginia Lake Festival, Buggs Island Lake, Clarksville, VA (a) Regulated Area. The following area is a...

Fine-grained sediment gravity flow deposits induced by flood and lake slope failure events: examples of lacustrine varved sediments in Japan

NASA Astrophysics Data System (ADS)

Ishihara, Yoshiro; Sasaki, Yasunori; Sasaki, Hana; Onishi, Yuri

2016-04-01

Fine-grained sediment gravity flow deposits induced by flood and lake slope failure events are frequently intercalated in lacustrine successions. When sediment gravity flow deposits are present in varved sediments, it is suggested that they provide valuable information about sediment gravity flows, because they can easily trace laterally and can give the magnitude of erosion and recurrence interval of events. In addition, because large sedimentary bodies of stacked sediment gravity flow deposits in varved sediments of a calm lake are not suggested, a relatively simple depositional environment is expected. In the present study, we analysed sedimentary facies of sediment gravity flow deposits in varved lacustrine diatomites in the Middle Pleistocene Hiruzenbara and Miyajima formations in Japan, and concluded a depositional model of the lacustrine sediment gravity flow deposits. Varved diatomites: The Hiruzenbara Fm., a dammed lake fill as foots of Hiruzen Volcanos, is deposited during an interglacial period during MIS12 to 15. Varves of ca. 8000 yr were measured in a 20 m intercalating flood and lake slope failure-induced sediment gravity flow deposits. The Miyajima Fm., distributed in a paleo-caldera lake in NE Japan, includes many sediment gravity flow deposits possibly originated from fandeltas around the lake. These formations have differences in their depositional setting; the Hiruzebara Fm. was deposited in a large lake basin, whereas the Miyajima Fm. was deposited in a relatively small basin. Because of the depositional setting, intercalation of volcaniclastics is dominant in the Miyajima Fm. Lacustrine sediment gravity flow deposits: Sediment gravity flow deposits in both formations can be classified into flood- and lake slope failure-induced types based on the sedimentary facies. Composites of the both types are also found. Flood-induced types comprise fine-grained silts dominated by carbonaceous fragments, whereas lake slope failure-induced types are

The most acidified Austrian lake in comparison to a neutralized mining lake

PubMed Central

Moser, Michael; Weisse, Thomas

2011-01-01

This study investigated two mining lakes located in the north of Lower Austria. These lakes arose 45 years ago when open cast lignite mining ceased. The lakes are separated by a 7-m wide dam. Due to the oxidation of pyrite, both lakes have been acidified and exhibit iron, sulphate, and heavy metal concentrations several orders of magnitude higher than in circumneutral lakes. The water column of both lakes is divided into two layers by a pronounced chemocline. The smaller mining lake (AML), with pH close to of 2.6, is the most acidic lake in Austria, whereas flooding with stream water and by drainage from the surrounding fields neutralized the adjacent larger pit lake. The goal of our study was to investigate the effect of flooding on its physical, chemical and biological properties, in comparison to the pristine AML. Even relative to other extremely acidic lakes, the flora and fauna in the AML was reduced and composed of only two flagellate, one ciliate, and one rotifer species. The simplified pelagic food web in the mixolimnion consisted of heterotrophic bacteria, the mixotrophic flagellates Chlamydomonas acidophila and Ochromonas sp., the ciliate Oxytricha sp., and the rotifer Cephalodella sp. The latter two are as yet undescribed new species. The heliozoan Actinophrys sp. that may act as top predator occurred only in low abundance. The euglenid Lepocinclis buetschlii formed a stable deep chlorophyll maximum (DCM) at 7 m depth. Highest cell numbers of L. buetschlii in the DCM exceeded 108 L−1. The neutralized mining lake harboured higher plankton diversity similar to that of natural circumneutral lakes. A peak of at least 16 different phytoplankton taxa was observed during summer. The zooplankton consisted of several copepod species, daphnids and other cladocerans, and at least six different rotifer species. Several fish species occurred in the neutralized lake. Although the effect of non-permanent flooding was largely sustainable, interannual fluctuations of

GEOCHEMICAL FEATURES OF WATER-ROCK INTERACTIONS AT THE SULPHUR BANK MERCURY MINE, LAKE COUNTY, CALIFORNIA

EPA Science Inventory

The Sulphur Bank Mercury Mine on the eastern shore of Clear Lake is the source of poor quality acid mine drainage seeping into Clear Lake. Lateral and vertical geochemical trends in ground water composition point to a number of redox reactions taking place as a function of subsu...

Anthropogenic effects on sedimentary facies in Lake Baldeney, West Germany

NASA Astrophysics Data System (ADS)

Neumann-Mahlkau, Peter; Niehaus, Heinz Theo

1983-12-01

Analysis of well logs of Lake Baldeney, a reservoir of the Ruhr River, yields four facies factors that reflect the effect of anthropogenic processes on the sediment. First, the sedimentation rate is directly related to the subsidence caused by mining. The extent of the subsidence was such that the sediment load of the river could not compensate for the sinking of the lake bottom. Discharged sediment filled about one-fifth of the basin within 40 years. In certain areas of the basin the sedimentation rate reached up to 10 cm per year. Second, the grain-size distribution of the sediment was influenced by long-term and short-term events. During the subsidence, grain-size distribution remained relatively constant. The destruction of the Möhne River dam during World War II resulted in the presence of an extremely large grain size as evidenced by the so-called Möhnelage. The filling of the lake after 1961 was accompanied by a continual increase in medium grain size. Third, until 1975, the mode of the lake sediment reflects the effect of mining in the vicinity of the lake. High coal content can be traced to its origin. The introduction of modern production processes, modernization of coal dressing, and hydraulic hauling is documented in the sediment. Finally, the heavy metal content of the sediment corresponds to the industrial development in the drainage area the Ruhr River. The accumulation of Cd reached an extreme concentration, exceeding the natural content by a thousand times. Variation in concentration reflects an increase in industrial production, as well as measures undertaken to restore water quality.

Selected satellite data on snow and ice in the Great Lakes basin 1972-73 /IFYGL/. [International Field Year for Great Lakes

NASA Technical Reports Server (NTRS)

Wiesnet, D. R.; Mcginnis, D. F.; Forsyth, D. G.

1974-01-01

Three snow-extent maps of the Lake Ontario drainage basin were prepared from NOAA-2 satellite visible band images during the International Field Year for the Great Lakes. These maps are discussed and the satellite data are evaluated for snow-extent mapping. The value of ERTS-1 imagery and digital data is also discussed in relation to the Lake Ontario basin studies. ERTS-1 MSS data are excellent for ice identification and analysis but are not useful for forecasting where timely receipt of data is imperative. NOAA-2 VHRR data are timely but the lower resolution of the VHRR makes identification of certain ice features difficult. NOAA-2 VHRR is well suited for snow-extent maps and thermal maps of large areas such as the 19,000 sq-km Lake Ontario basin.

Contrasting evolution patterns between glacier-fed and non-glacier-fed lakes in the central Tibetan Plateau and driving force analysis

NASA Astrophysics Data System (ADS)

Song, C.; Sheng, Y.

2015-12-01

High-altitude lakes in the Tibetan Plateau (TP) showed strong spatio-temporal variability during past decades. The lake dynamics can be associated with several key factors including lake type, supply of glacial meltwater, local climate variations. It is important to differentiate these factors when analyzing the driving force of lakes dynamics. With a focus on lakes over the Tanggula Mountains of the central TP, this study investigates the temporal evolution patterns of lake area and water level of different types: glacier-fed closed lake, non-glacier-fed closed lake and upstream lake (draining into closed lakes). We collected all available Landsat archive data and quantified the inter-annual variability of lake extents. Results show accelerated expansions of both glacier-fed and non-glacier-fed lakes during 1970s-2013, and different temporal patterns of the two types of lakes: the non-glacier-fed lakes displayed a batch-wise growth pattern, with obvious growth in 2002, 2005 and 2011 and slight changes in other years, while glacier-fed lakes showed steady expanding tendency. The contrasting patterns are confirmed by the distinction of lake level change between the two groups derived from satellite altimetry during 2003-2009. The upstream lakes remained largely stable due to natural drainage regulation. The intermittent expansions for non-glacier-fed lakes were found to be related to excessive precipitation events and positive "precipitation-evaporation". In contrast, glacier-fed lake changes showed weak correlations with precipitation variations, which imply a joint contribution from glacial meltwater to water budgets. A simple estimation reveals that the increased water storage for all of examined lakes contributed from precipitation/evaporation (0.31±0.09 Gt/yr) slightly overweighed the glacial meltwater supply (0.26±0.08 Gt/yr).

A 100-year sedimentary record of natural and anthropogenic impacts on a shallow eutrophic lake, Lake Chaohu, China.

PubMed

Zan, Fengyu; Huo, Shouliang; Xi, Beidou; Zhu, Chaowei; Liao, Haiqing; Zhang, Jingtian; Yeager, Kevin M

2012-03-01

In this study, the sediment profiles of total organic carbon, total nitrogen, C/N ratios, total phosphorus, N/P ratios, C/P ratios, particle sizes, and stable carbon and nitrogen isotopes (δ(13)C and δ(15)N) were used to investigate natural and anthropogenic impacts on Lake Chaohu over the past 100 years. Before 1960, Lake Chaohu experienced low productivity and a relatively steady and low nutrient input. The increasing concentration and fluxes of total organic carbon, total nitrogen, total phosphorus, together with changes in the δ(13)C and δ(15)N of organic material in the sediment cores, suggested that the anthropogenic effects on trophic status first started because of an increase in nutrient input caused by a population increase in the drainage area. With the construction of the Chaohu Dam, an increase in the utilization of fertilizer and the population growth which occurred since 1960, stable depositional conditions and increasing nutrient input resulted in a dominantly algae-derived organic matter source and high productivity. Nutrient input increased most significantly around 1980 following the rapidly growing population, with concomitant urbanization, industrial and agricultural development. This study also revealed that the concentration and distribution of nutrients varied between different areas of sediment within Lake Chaohu because of the influence of different drainage basins and pollution sources. This journal is © The Royal Society of Chemistry 2012

Evaluation of an early warning system for glacial lake outburst flood (GLOF) events in Huaraz, Peru

NASA Astrophysics Data System (ADS)

McKinney, D. C.; Somos-Valenzuela, M. A.

2014-12-01

People in Cordillera Blanca range in Peru have a long history dealing with natural disasters associated to high mountains; particularly Glacier Lakes Outburst Flood (GLOF). Examples in the Cordillera Blanca vary from a GLOF that occurred in 1941 that killed more than 5000 people in the city of Huaraz to recent events from Lake Artison Baja in 2012 and Lake 513 on 2010, which were not devastating thanks to safety systems previously installed in those lakes. However, glaciers continue melting leaving new lakes or changing the characteristics of lakes that were previously controlled making safety systems obsolete that worked successfully in the past protecting communities downstream. Lake Palcacocha has evolved from being safe after the installation of a safety system in 1970 to an imminent source of GLOF risk due to the expansion that has occurred during the last 40 years increasing from a volume of 500,000 to 17 million m3. In response to this risk the community in Huaraz is planning an Early Warning System (EWS) that will allow the population to mobilize to a safe area in case a GLOF occurs. In this work we present an adaptation of the LifeSIM model to calculate the benefits from such an EWS using 2007 census data and a FLO-2D flood simulation model. The outputs are the number of people in Huaraz that could lose their life due to a GLOF. Our results indicate that without an EWS around 19,773 people could lose their life; whereas, if an EWS is installed the number of victims reduces to 7344. Finally, if mobilization of the affected population is improved the value reduces to 2865. The results show the importance of the EWS as well as informing and training the population to how to react if a GLOF occurs.

Local response of a glacier to annual filling and drainage of an ice-marginal lake

USGS Publications Warehouse

Walder, J.S.; Trabant, D.C.; Cunico, M.; Fountain, A.G.; Anderson, S.P.; Anderson, R. Scott; Malm, A.

2006-01-01

Ice-marginal Hidden Creek Lake, Alaska, USA, outbursts annually over the course of 2-3 days. As the lake fills, survey targets on the surface of the 'ice dam' (the glacier adjacent to the lake) move obliquely to the ice margin and rise substantially. As the lake drains, ice motion speeds up, becomes nearly perpendicular to the face of the ice dam, and the ice surface drops. Vertical movement of the ice dam probably reflects growth and decay of a wedge of water beneath the ice dam, in line with established ideas about jo??kulhlaup mechanics. However, the distribution of vertical ice movement, with a narrow (50-100 m wide) zone where the uplift rate decreases by 90%, cannot be explained by invoking flexure of the ice dam in a fashion analogous to tidal flexure of a floating glacier tongue or ice shelf. Rather, the zone of large uplift-rate gradient is a fault zone: ice-dam deformation is dominated by movement along high-angle faults that cut the ice dam through its entire thickness, with the sense of fault slip reversing as the lake drains. Survey targets spanning the zone of steep uplift gradient move relative to one another in a nearly reversible fashion as the lake fills and drains. The horizontal strain rate also undergoes a reversal across this zone, being compressional as the lake fills, but extensional as the lake drains. Frictional resistance to fault-block motion probably accounts for the fact that lake level falls measurably before the onset of accelerated horizontal motion and vertical downdrop. As the overall fault pattern is the same from year to year, even though ice is lost by calving, the faults must be regularly regenerated, probably by linkage of surface and bottom crevasses as ice is advected toward the lake basin.

Genetic differentiation of sockeye salmon subpopulations from a geologically young Alaskan lake system

USGS Publications Warehouse

Burger, C.V.; Spearman, William J.; Cronin, M.A.

1997-01-01

The Tustumena lake drainage in southcentral Alaska is glacially turbid and geologically young (<2,000 years old). Previous field studies identified at least three subpopulations of sockeye salmon Oncorhynchus nerka at Tustumena Lake, based on the distribution and timing of spawners. The subpopulations included early-run salmon that spawned in six clearwater tributaries of the lake (mid August), lake shoreline spawners (late August), and late-run fish that spawned in the lake's outlet, the Kasilof River (late September). Our objective was to determine the degree of genetic differentiation among these subpopulations based on restriction enzyme analyses of the cytochrome b gene of mitochondrial DNA and analyses of four polymorphic allozyme loci. Mitochondrial DNA haplotype frequencies for outlet-spawning sockeye salmon differed significantly from those of all other subpopulations. The most common (36%) haplotype in the outlet subpopulation did not occur elsewhere, thus suggesting little or no gene flow between outlet spawners and other spatially close subpopulations at Tustumena Lake. Allele frequencies at two allozyme loci also indicated a degree of differentiation of the outlet subpopulation from the shoreline and tributary subpopulations. Allele frequencies for three tributary subpopulations were temporally stable over approximately 20 years (based on a comparison to previously published results) despite initiation of a hatchery program in two of the tributaries during the intervening period. Collectively, our results are consistent with the hypothesis that significant genetic differentiation has occurred within the Tustumena Lake drainage since deglaciation approximately 2,000 years ago.

A&M. Grading and drainage plan. Shows natural ground elevation of ...

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

A&M. Grading and drainage plan. Shows natural ground elevation of the (presumed) dry lake-bed shore and berm shielding the administrative area from the hot shop area. Ralph M. Parsons 902-2&3-ANP-U 4. Date: December 1953. Approved by INEEL Classification Office for public release. INEEL code no. 032-0000-00-693-106691 - Idaho National Engineering Laboratory, Test Area North, Scoville, Butte County, ID

Fault-dominated deformation in an ice dam during annual filling and drainage of a marginal lake

USGS Publications Warehouse

Walder, J.S.; Trabant, D.C.; Cunico, M.; Anderson, S.P.; Anderson, R. Scott; Fountain, A.G.; Malm, A.

2005-01-01

Ice-dammed Hidden Creek Lake, Alaska, USA, outbursts annually in about 2-3 days. As the lake fills, a wedge of water penetrates beneath the glacier, and the surface of this 'ice dam' rises; the surface then falls as the lake drains. Detailed optical surveying of the glacier near the lake allows characterization of ice-dam deformation. Surface uplift rate is close to the rate of lake-level rise within about 400 m of the lake, then decreases by 90% over about 100 m. Such a steep gradient in uplift rate cannot be explained in terms of ice-dam flexure. Moreover, survey targets spanning the zone of steep uplift gradient move relative to one another in a nearly reversible fashion as the lake fills and drains. Evidently, the zone of steep uplift gradient is a fault zone, with the faults penetrating the entire thickness of the ice dam. Fault motion is in a reverse sense as the lake fills, but in a normal sense as the lake drains. As the overall fault pattern is the same from year to year, even though ice is lost by calving, the faults must be regularly regenerated, probably by linkage of surface and bottom crevasses as ice is advected toward the lake basin.

Occurrence of and trends in selected sediment-associated contaminants in Caddo Lake, East Texas, 1940-2002

USGS Publications Warehouse

Wilson, Jennifer T.

2003-01-01

Bottom-sediment cores were collected from four sites in Caddo Lake in East Texas during May 2002 for analyses of radionuclides (for age dating), organochlorine pesticides, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and major and trace elements, and to describe the occurrence and trends of these sediment-associated contaminants. The Goose Prairie Creek and Harrison Bayou sites receive drainage from an area that includes parts of the now-closed Longhorn Army Ammunitions Plant. The mid-lake site is relatively close to dense oil and gas operations in the lake. The Carter Lake site receives minimal discharge from developed areas. Sediment age (deposition) dates represented in the cores ranged from 1940 to 2002. The only organochlorine compounds detected in all core samples were the DDT degradation products DDE or DDD, and PCB Aroclors 1242, 1254, and 1260 were detected only at the Goose Prairie Creek site. One or more of the DDE concentrations at all sites exceeded a consensus-based threshold effect concentration (on benthic biota), but none exceeded a consensus-based probable effect concentration. The Goose Prairie Creek site had significant downward trends in concentrations of organochlorine compounds, except for no trend in DDE concentrations. The Ammunitions Plant is a possible historical source of the few organochlorine compounds detected at the Goose Prairie Creek and Harrison Bayou sites. PAH concentrations at all sites were below respective threshold effect concentrations. Highest PAH concentrations at all four sites were of C2- alkylated naphthalenes. Nearly all statistically significant PAH trends in the cores were downward. On the basis of PAH source-indicator ratios, the majority of PAH compounds appear to have originated from uncombusted sources such as leaks or spills from oil and gas operations or vehicles (automobiles, boats, aircraft) in the Caddo Lake area. Concentrations of several of the eight trace elements with

How Might Draining Lake Campotosto Affect Stress and Seismicity on the Monte Gorzano Normal Fault, Central Italy?

NASA Astrophysics Data System (ADS)

Verdecchia, A.; Deng, K.; Harrington, R. M.; Liu, Y.

2017-12-01

It is broadly accepted that large variations of water level in reservoirs may affect the stress state on nearby faults. While most studies consider the relationship between lake impoundment and the occurrence of large earthquakes or seismicity rate increases in the surrounding region, very few examples focus on the effects of lake drainage. The second largest reservoir in Europe, Lake Campotosto, is located on the hanging wall of the Monte Gorzano fault, an active normal fault responsible for at least two M ≥ 6 earthquakes in historical times. The northern part of this fault ruptured during the August 24, 2016, Mw 6.0 Amatrice earthquake, increasing the probability for a future large event on the southern section where an aftershock sequence is still ongoing. The proximity of the Campotosto reservoir to the active fault aroused general concern with respect to the stability of the three dams bounding the reservoir if the southern part of the Monte Gorzano fault produces a moderate earthquake. Local officials have proposed draining the reservoir as hazard mitigation strategy to avoid possible future catastrophes. In efforts to assess how draining the reservoir might affect earthquake nucleation on the fault, we use a finite-element poroelastic model to calculate the evolution of stress and pore pressure in terms of Coulomb stress changes that would be induced on the Monte Gorzano fault by emptying the Lake Campotosto reservoir. Preliminary results show that an instantaneous drainage of the lake will produce positive Coulomb stress changes, mostly on the shallower part of the fault (0 to 2 km), while a stress drop of the order of 0.2 bar is expected on the Monte Gorzano fault between 0 and 8 km depth. Earthquake hypocenters on the southern portion of the fault currently nucleate between 5 and 13 km depth, with activity distributed nearby the reservoir. Upcoming work will model the effects of varying fault geometry and elastic parameters, including geological

Authigenic carbonate precipitation in Lake Acigöl, a hypersaline lake in southwestern Turkey

NASA Astrophysics Data System (ADS)

Balci, Nurgul; Menekse, Meryem; Gül Karagüler, Nevin; Seref Sönmez, M.; Meister, Patrick

2014-05-01

Lake Acigöl (Bitter Lake) is a hypersaline lake in southwestern Turkey at an elevation of 836 m above sea level showing authigenic precipitation of several different carbonate mineral phases. It is a perennial lake and closed drainage basin where a semiarid continental climate dominates. Due to the extreme water chemistry (salinity 8-200 mg/l; SO4 112-15232 mg/l; Cl 290-35320 mg/l; Mg, 82-3425 mg/l; Ca 102-745 mg/l) unique microorganisms flourish in the lake. We studied microbial diversity from enrichment cultures and performed precipitation experiments using similar water chemistry and adding bacterial enrichment cultures from lake sediments in order to elucidate whether the mineral assemblages found in the lake can be reproduced. Experiments using moderately halophilic bacteria obtained from the lake sediments demonstrate the formation of various calcium-/magnesium-carbonates: hydromagnesite, dypingite, huntite, monohydrocalcite and aragonite. The relative amounts of different mineral phases, particularly monohydrocalcite, hydromagnesite and dypingite, could be controlled by varying the sulphate concentration in the media from 0 to 56 mM. The similar mineral assemblages identified in the sediments of Lake Acigöl and in the experiments point to similar thermodynamic conditions and kinetics of crystal growth. In particular, the similar spherical morphology points to a rapid crystal growth under strong kinetic inhibition, possibly by organic polymers that are commonly produced by microbial communities. Our results demonstrate that the authigenic carbonate paragenesis of hypersaline lakes as Lake Acigöl can be reproduced in halophilic bacterial cultures. The exact thermodynamic conditions and precipitation kinetics under seasonally changing water chemistry or in batch experiment, however, still have to be constrained in order to establish a microbial model for carbonate precipitation in such environments.

Response of the St. Joseph River to lake level changes during the last 12,000 years in the Lake Michigan basin

USGS Publications Warehouse

Kincare, K.A.

2007-01-01

The water level of the Lake Michigan basin is currently 177 m above sea level. Around 9,800 14C years B.P., the lake level in the Lake Michigan basin had dropped to its lowest level in prehistory, about 70 m above sea level. This low level (Lake Chippewa) had profound effects on the rivers flowing directly into the basin. Recent studies of the St. Joseph River indicate that the extreme low lake level rejuvenated the river, causing massive incision of up to 43 m in a valley no more than 1.6 km wide. The incision is seen 25 km upstream of the present shoreline. As lake level rose from the Chippewa low, the St. Joseph River lost competence and its estuary migrated back upstream. Floodplain and channel sediments partially refilled the recently excavated valley leaving a distinctly non-classical morphology of steep sides with a broad, flat bottom. The valley walls of the lower St. Joseph River are 12-18 m tall and borings reveal up to 30 m of infill sediment below the modern floodplain. About 3 ?? 108 m3 of sediment was removed from the St. Joseph River valley during the Chippewa phase lowstand, a massive volume, some of which likely resides in a lowstand delta approximately 30 km off-shore in Lake Michigan. The active floodplain below Niles, Michigan, is inset into an upper terrace and delta graded to the Calumet level (189 m) of Lake Chicago. In the lower portion of the terrace stratigraphy a 1.5-2.0 m thick section of clast-supported gravel marks the entry of the main St. Joseph River drainage above South Bend, Indiana, into the Lake Michigan basin. This gravel layer represents the consolidation of drainage that probably occurred during final melting out of ice-marginal kettle chains allowing stream piracy to proceed between Niles and South Bend. It is unlikely that the St. Joseph River is palimpsest upon a bedrock valley. The landform it cuts across is a glaciofluvial-deltaic feature rather than a classic unsorted moraine that would drape over pre-glacial topography

33 CFR 100.35T09-0327 - Special Regulated Areas for summer events; Captain of the Port Lake Michigan Zone.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Special Regulated Areas for summer events; Captain of the Port Lake Michigan Zone. 100.35T09-0327 Section 100.35T09-0327 Navigation... OF LIFE ON NAVIGABLE WATERS § 100.35T09-0327 Special Regulated Areas for summer events; Captain of...

Microplastic pollution in lakes and lake shoreline sediments - A case study on Lake Bolsena and Lake Chiusi (central Italy).

PubMed

Fischer, Elke Kerstin; Paglialonga, Lisa; Czech, Elisa; Tamminga, Matthias

2016-06-01

Rivers and effluents have been identified as major pathways for microplastics of terrestrial sources. Moreover, lakes of different dimensions and even in remote locations contain microplastics in striking abundances. This study investigates concentrations of microplastic particles at two lakes in central Italy (Lake Bolsena, Lake Chiusi). A total number of six Manta Trawls have been carried out, two of them one day after heavy winds occurred on Lake Bolsena showing effects on particle distribution of fragments and fibers of varying size categories. Additionally, 36 sediment samples from lakeshores were analyzed for microplastic content. In the surface waters 2.68 to 3.36 particles/m(3) (Lake Chiusi) and 0.82 to 4.42 particles/m(3) (Lake Bolsena) were detected, respectively. Main differences between the lakes are attributed to lake characteristics such as surface and catchment area, depth and the presence of local wind patterns and tide range at Lake Bolsena. An event of heavy winds and moderate rainfall prior to one sampling led to an increase of concentrations at Lake Bolsena which is most probable related to lateral land-based and sewage effluent inputs. The abundances of microplastic particles in sediments vary from mean values of 112 (Lake Bolsena) to 234 particles/kg dry weight (Lake Chiusi). Lake Chiusi results reveal elevated fiber concentrations compared to those of Lake Bolsena what might be a result of higher organic content and a shift in grain size distribution towards the silt and clay fraction at the shallow and highly eutrophic Lake Chiusi. The distribution of particles along different beach levels revealed no significant differences. Copyright © 2016 Elsevier Ltd. All rights reserved.

Physical modeling of transverse drainage mechanisms

NASA Astrophysics Data System (ADS)

Douglass, J. C.; Schmeeckle, M. W.

2005-12-01

Streams that incise across bedrock highlands such as anticlines, upwarps, cuestas, or horsts are termed transverse drainages. Their relevance today involves such diverse matters as highway and dam construction decisions, location of wildlife corridors, better-informed sediment budgets, and detailed studies into developmental histories of late Cenozoic landscapes. The transient conditions responsible for transverse drainage incision have been extensively studied on a case-by-case basis, and the dominate mechanisms proposed include: antecedence, superimposition, overflow, and piracy. Modeling efforts have been limited to antecedence, and such the specific erosional conditions required for transverse drainage incision, with respect to the individual mechanisms, remains poorly understood. In this study, fifteen experiments attempted to simulate the four mechanisms and constructed on a 9.15 m long, 2.1 m wide, and 0.45 m deep stream table. Experiments lasted between 50 and 220 minutes. The stream table was filled with seven tons of sediment consisting of a silt and clay (30%) and a fine to coarse sand (70%) mixture. The physical models highlighted the importance of downstream aggradation with regard to antecedent incision versus possible defeat and diversion. The overflow experiments indicate that retreating knickpoints across a basin outlet produce a high probability of downstream flooding when associated with a deep lake. Misters used in a couple of experiments illustrate a potential complication with regard to headward erosion driven piracy. Relatively level asymmetrically sloped ridges allow for the drainage divide across the ridge to retreat from headward erosion, but hindered when the ridge's apex undulates or when symmetrically sloped. Although these physical models cannot strictly simulate natural transverse drainages, the observed processes, their development over time, and resultant landforms roughly emulate their natural counterparts. Proposed originally from

Isotopic mixing model for quantifying contributions of soil water and groundwater in subsurface ('tile') drainage

NASA Astrophysics Data System (ADS)

Kennedy, C. D.; Gall, H.; Jafvert, C. T.; Bowen, G. J.

2010-12-01

Subsurface (‘tile’) drainage, consisting of buried grids of perforated pipe, has provided a means of converting millions of acres of poorly drained soils in the Midwestern U.S. into fertile cropland. However, by altering pathways and rates of soil water and groundwater movement through agricultural lands, this practice may accelerate the loss of nitrate and other agrochemicals. To better understand the hydrological controls on nitrogen dynamics in artificially drained agricultural watersheds, a field sampling program has been established at the Animal Science Research and Education Center (ASREC) at Purdue University (West Lafayette, Indiana) to (1) measure precipitation amount, tile flow, and water-table elevation, and (2) collect water samples for analysis of nitrate, major ions, and oxygen isotope ratios in precipitation, tile drainage, shallow (1 m) and deep (3 m) groundwater, and soil water during storm events. Preliminary physical, chemical, and isotopic data collected at the ASREC show a coincident timing of peak storm ‘event water’ and peak nitrate flux in tile drainage, suggesting significant routing of infiltrating event water. In this work, we aim to refine our understanding of tile drainage at the ASREC by developing a mixing model for partitioning contributions of soil water and groundwater in tile drainage during several storm runoff events ranging in precipitation intensity and coinciding with varying antecedent soil moisture conditions. The results of our model will describe tile drainage in terms of its hydrological components, soil water and groundwater, which in turn will provide a means of incorporating the effects of tile drainage in surface/subsurface hydrological transport models.

Levels of Plant Available Phosphorus in Agricultural Soils in the Lake Erie Drainage Basin.

DTIC Science & Technology

1977-12-01

total P tributary load to Lake Erie is in the form of Tsediment-P and most of the sediment -P is of surficial soil origin. Total P load can be related...extremely high ranges can be attributed to 1) and 2) above. Lake Erie counties in Ontario were identified (Figure 3 ) and published reports of the...M-I -28- -tq 𔃾 way.’ .*..... . .. .. ... oi 111 1111; l -29- Table 8 Available-P in Ontario soils in Lake Erie Basin counties Available*-P (ug/g

Tracing Changes in Carbon Chemistry Caused by an Extreme Mid-Summer Rain Event in a Lake-Stream System in the Colorado Rocky Mountains

NASA Astrophysics Data System (ADS)

Miller, M.; McKnight, D.; Alexander, K.

2006-12-01

We studied the impact of a sustained high elevation rain event in mid-summer on the biogeochemistry of dissolved organic material (DOM) in an aquatic ecosystem in the Colorado Front Range. In the Green Lakes Valley, an alpine-subalpine catchment, the hydrology is typically defined by two distinct periods: snowmelt and baseflow. Similarly, characterization of DOM by fluorescence spectroscopy and other methods shows that the source and chemical character of the DOM changes with the hydrology. Surface water samples were collected from the outlet of a small alpine lake as well as a stream site downstream of a larger subalpine lake from the initiation of snowmelt through late summer. Beginning on July 7th and ending on July 9th 2006 a continuous low intensity rain event produced approximately 9 cm of precipitation. The rain event increased discharge at the two sites to flow rates that were 2.5 fold greater than those observed during peak snowmelt. The fluorescence characteristics of the DOM as well as the percent fulvic acid contribution to the sample were reset to values similar to those observed during snowmelt at the alpine site but were relatively unaffected at the subalpine site. These results suggest that alpine ecosystems are more sensitive to hydrologic changes than subalpine ecosystems and residence times of the lakes in these systems may play an important role in regulating stream chemistry.

Planktonic events may cause polymictic-dimictic regime shifts in temperate lakes

PubMed Central

Shatwell, Tom; Adrian, Rita; Kirillin, Georgiy

2016-01-01

Water transparency affects the thermal structure of lakes, and within certain lake depth ranges, it can determine whether a lake mixes regularly (polymictic regime) or stratifies continuously (dimictic regime) from spring through summer. Phytoplankton biomass can influence transparency but the effect of its seasonal pattern on stratification is unknown. Therefore we analysed long term field data from two lakes of similar depth, transparency and climate but one polymictic and one dimictic, and simulated a conceptual lake with a hydrodynamic model. Transparency in the study lakes was typically low during spring and summer blooms and high in between during the clear water phase (CWP), caused when zooplankton graze the spring bloom. The effect of variability of transparency on thermal structure was stronger at intermediate transparency and stronger during a critical window in spring when the rate of lake warming is highest. Whereas the spring bloom strengthened stratification in spring, the CWP weakened it in summer. The presence or absence of the CWP influenced stratification duration and under some conditions determined the mixing regime. Therefore seasonal plankton dynamics, including biotic interactions that suppress the CWP, can influence lake temperatures, stratification duration, and potentially also the mixing regime. PMID:27074883

Planktonic events may cause polymictic-dimictic regime shifts in temperate lakes.

PubMed

Shatwell, Tom; Adrian, Rita; Kirillin, Georgiy

2016-04-14

Water transparency affects the thermal structure of lakes, and within certain lake depth ranges, it can determine whether a lake mixes regularly (polymictic regime) or stratifies continuously (dimictic regime) from spring through summer. Phytoplankton biomass can influence transparency but the effect of its seasonal pattern on stratification is unknown. Therefore we analysed long term field data from two lakes of similar depth, transparency and climate but one polymictic and one dimictic, and simulated a conceptual lake with a hydrodynamic model. Transparency in the study lakes was typically low during spring and summer blooms and high in between during the clear water phase (CWP), caused when zooplankton graze the spring bloom. The effect of variability of transparency on thermal structure was stronger at intermediate transparency and stronger during a critical window in spring when the rate of lake warming is highest. Whereas the spring bloom strengthened stratification in spring, the CWP weakened it in summer. The presence or absence of the CWP influenced stratification duration and under some conditions determined the mixing regime. Therefore seasonal plankton dynamics, including biotic interactions that suppress the CWP, can influence lake temperatures, stratification duration, and potentially also the mixing regime.

Spatial dynamics of thermokarst and thermo-erosion at lakes and ponds in North Siberia and Northwest Alaska using high-resolution remote sensing

NASA Astrophysics Data System (ADS)

Grosse, G.; Tillapaugh, M.; Romanovsky, V. E.; Walter, K. M.; Plug, L. J.

2008-12-01

Formation, growth, and drainage of thermokarst lakes in ice-rich permafrost deposits are important factors of landscape dynamics in extent Arctic lowlands. Monitoring of spatial and temporal dynamics of such lakes will allow an assessment of permafrost stability and enhance the capabilities for modelling and quantifying biogeochemical processes related to permafrost degradation in a warming Arctic. In this study we use high-resolution remote sensing and GIS to analyze the development of thermokarst lakes and ponds in two study regions in North Siberia and Northwest Alaska. The sites are 1) the Cherskii region in the Kolyma lowland (Siberia) and 2) the Kitluk River area on the northern Seward Peninsula (Alaska). Both regions are characterized by continuous permafrost, a highly dissected and dynamic thermokarst landscape, uplands of Late Pleistocene permafrost deposits with high excess ice contents, and a large total volume of permafrost-stored carbon. These ice-rich Yedoma or Yedoma-like deposits are highly vulnerable to permafrost degradation forced by climate warming or other surface disturbance. Time series of high- resolution imagery (aerial, Corona, Ikonos, Alos Prism) covering more than 50 years of lake dynamics allow detailed assessments of processes and spatial patterns of thermokarst lake expansion and drainage in continuous permafrost. Time series of high-resolution imagery (aerial, Corona, Ikonos, Alos Prism) covering more than 50 years of lake dynamics allow detailed assessments of processes and spatial patterns of thermokarst lake expansion and drainage in continuous permafrost. Processes identified include thaw slumping, wave undercutting of frozen sediments or peat blocks and subsequent mass wasting, thaw collapse of near-shore zones, sinkhole formation and ice-wedge tunnelling, and gully formation by thermo-erosion. We use GIS-based tools to relate the remote sensing results to field data (ground ice content, topography, lithology, and relative age

Stratigraphic framework and lake level history of Lake Kivu, East African Rift

NASA Astrophysics Data System (ADS)

Wood, Douglas A.; Scholz, Christopher A.

2017-10-01

Sediment cores and seismic reflection data acquired from the eastern basin of Lake Kivu, Rwanda reveal extensive limnologic variations due to changes in regional climate and basin structure. The eastern basin of the lake contains a sedimentary wedge which is > 1.5 km in thickness on its western side, and basal sediments are estimated to be at least 1.5 million years old. Sediments are likely to be thicker and older than this in the northern, Congolese basin of the lake. Above the ∼300 m iosbath only a thin layer of Holocene sediments are observed indication that this may have been the lake's high stand prior to that time. There are at least three erosional unconformities interpreted as desiccation or near-desiccation events which are estimated to have occurred at ∼475 ka, ∼100 ka, and ∼20 ka; the two most recent of these low stages likely developed during the African Megadrought and Last Glacial Maximum (LGM) periods. Following the LGM, the water levels rose to form a ∼100 m deep lake with its surface ∼370 m below the current lake level. The lake remained near that level for several thousand years and during this time the Virunga Volcanic Province expanded. At ∼12.2 ka a change to wetter climate conditions rapidly filled the lake to spill out of the Bukavu Bay basin southward toward Lake Tanganyika. Tephra sampled from the cores show that there have been at least 24 large local volcanic events since the early Holocene lake transgression.

Neogene Rift Propagation of the East African Rift System (EARS) into Central Africa and its Implications: Tectonic, Topographic and Geomorphic Impacts of the Luangwa and Luapula Rift Valleys on the Upper Congo Drainage Basin, Lake Bangweulu Wetlands and the Development of the Diffuse Southwestern Tip of the EARS.

NASA Astrophysics Data System (ADS)

Daly, M. C.; Watts, A. B.

2017-12-01

Integration of geomorphology, seismic reflection and gravity data, seismicity, DEM analysis and modelling defines a zone of NE/SW trending rifts extending into Central and SW Africa, orthogonal to the conventionally defined East African Rift System (EARS). These large-scale tectonic features have a relatively low level of seismicity and volcanism compared to the EARS, yet they generate significant topography and control the upper Congo drainage basin. They may also represent the beginning of an active but diffuse plate boundary developing to the southwest across Central Africa. The dominant feature of this broad zone is the Luangwa Rift Valley of eastern Zambia. Seismic reflection data show the Luangwa Rift developed as a thick ( 5km) Permo-Triassic basin. Inverted in the Mesozoic, it then experienced major Neogene extensional reactivation. The latter resulted in today's major border faults of varying polarity, with fault plane escarpments of up to 1000m, and associated rift flank uplifts that elevate the Central African plateau surface by 200 m. Late Miocene alluvial fans indicate a minimum age for the initiation of reactivation. Although having similar structural features to the EARS, the Luangwa Rift has a lower level of active seismicity and volcanism. 400 km northwest of the Luangwa, the north/south Luapula rift valley passes into the NE trending Mweru and Mweru Wantipa rift lakes. Pronounced border faults and fault terraces mark the NW and SE margins of these shallow lakes. Between the Luangwa and Luapula rift valleys lies the extensive upper Congo drainage basin of the Chambeshi river and the Lake Bangweulu wetlands. DEM mapping of topography from the Luangwa rift to the Luapula-Mweru Wantipa rift shows a low amplitude, large wavelength flexure of the Central African plateau surface compatible with an effective elastic thickness of 35 km. This regional warping controls the location and shape of the Chambeshi drainage basin and the Lake Bangweulu Wetlands

Preoperative biliary drainage in hilar cholangiocarcinoma: When and how?

PubMed Central

Paik, Woo Hyun; Loganathan, Nerenthran; Hwang, Jin-Hyeok

2014-01-01

Hilar cholangiocarcinoma is a tumor of the extrahepatic bile duct involving the left main hepatic duct, the right main hepatic duct, or their confluence. Biliary drainage in hilar cholangiocarcinoma is sometimes clinically challenging because of complexities associated with the level of biliary obstruction. This may result in some adverse events, especially acute cholangitis. Hence the decision on the indication and methods of biliary drainage in patients with hilar cholangiocarcinoma should be carefully evaluated. This review focuses on the optimal method and duration of preoperative biliary drainage (PBD) in resectable hilar cholangiocarcinoma. Under certain special indications such as right lobectomy for Bismuth type IIIA or IV hilar cholangiocarcinoma, or preoperative portal vein embolization with chemoradiation therapy, PBD should be strongly recommended. Generally, selective biliary drainage is enough before surgery, however, in the cases of development of cholangitis after unilateral drainage or slow resolving hyperbilirubinemia, total biliary drainage may be considered. Although the optimal preoperative bilirubin level is still a matter of debate, the shortest possible duration of PBD is recommended. Endoscopic nasobiliary drainage seems to be the most appropriate method of PBD in terms of minimizing the risks of tract seeding and inflammatory reactions. PMID:24634710

Water budget and estimated suspended-sediment inflow for Reelfoot Lake, Obion and Lake Counties, Northwestern Tennessee, May 1984-April 1985

USGS Publications Warehouse

Robbins, Clarence H.

1985-01-01

Reelfoot Lake in northwestern Tennessee, with a surface area of 15,500 acres at normal pool elevation, is the largest natural lake in Tennessee. Over the years, the lake has become an important economic, environmental, and recreational resource to the people in the area, and to the State of Tennessee. The natural eutrophic succession rate of the lake has apparently been accelerated by land use practices within the Reelfoot Lake drainage basin during the past several decades. The potential loss of Reelfoot Lake has prompted the State to make management and restoration of the lake and its resources a priority objective. The U.S. Geological Survey entered into a cooperative study in May 1984 with the Tennessee Wildlife Resources Agency and the Tennessee Department of Health and Environment, Division of Water Management, to collect and analyze hydrologic data and prepare an annual water budget for Reelfoot Lake. The purpose of the water budget is to provide an analysis of the surface-groundwater-lake-atmospheric water relation at Reelfoot Lake. Results of the analysis can be used by lake managers to evaluate the potential effects of proposed lake management strategies upon the lake and surrounding hydrologic system. The water budget for the 12-month study period (May 1, 1984 through April 30, 1985) is presented in this report. In addition, estimates of suspended-sediment discharge from tributary streams in the Reelfoot Lake basin and an analysis of concentrations of constituents in stream-bottom material at three inflow sites are also presented. (Lantz-PTT)

Abrupt lake-level changes in the Rocky Mountains and surrounding regions since the Last Glacial Maximum

NASA Astrophysics Data System (ADS)

Shuman, B. N.; Serravezza, M.

2016-12-01

The paleohydrologic record of western North America since the last glacial maximum reveals a wide range of hydroclimatic variability and distinctive patterns associated with abrupt climate changes. To evaluate the sequence of abrupt hydroclimatic shifts and centennial-to-millennial hydrologic variability in western North America over the past 17 ka, we reconstruct lake-level histories from two high-elevation lakes in the Beartooth and Bighorn Mountains. The lakes represent the headwaters of the Missouri River drainage in northern Wyoming, but also have the potential to capture regional hydroclimate variability that links the northern Rocky Mountains to the mid-continent, Pacific Northwest, and the Great Basin. We first discuss the stratigraphic record of lake-level changes in small mid-latitude lakes and then use ground-penetrating radar (GPR) and sediment cores to track the elevations of shoreline sediments within the lakes through time. We compare the stratigraphies to the records from four other lakes in Wyoming and Colorado, and find widespread evidence for a Terminal Pleistocene Drought from 15-11 ka, an early Holocene humid period from 11-8 ka, and a period of severe mid-Holocene aridity from 8-5.7 ka. The northern Wyoming lakes also provide evidence of high levels before ca. 15 ka, including rapid hydroclimatic changes at ca. 16.8 ka during Heinrich Event 1. We place the changes in a broad context by summarizing and mapping water-level changes from 107 additional, previously studied lakes. Important patterns include 1) extensive drying across the western U.S. after 15 ka; 2) coherent sub-regional differences during the Younger Dryas and Pleistocene-Holocene transition; 3) a north-south contrast from 9-6 ka consistent with a northward shift in storm tracks as the influence of the Laurentide Ice Sheet diminished; and 4) rapid increases in effective moisture across much of western North America from 6-4 ka.

Possible origin and significance of extension-parallel drainages in Arizona's metamophic core complexes

USGS Publications Warehouse

Spencer, J.E.

2000-01-01

The corrugated form of the Harcuvar, South Mountains, and Catalina metamorphic core complexes in Arizona reflects the shape of the middle Tertiary extensional detachment fault that projects over each complex. Corrugation axes are approximately parallel to the fault-displacement direction and to the footwall mylonitic lineation. The core complexes are locally incised by enigmatic, linear drainages that parallel corrugation axes and the inferred extension direction and are especially conspicuous on the crests of antiformal corrugations. These drainages have been attributed to erosional incision on a freshly denuded, planar, inclined fault ramp followed by folding that elevated and preserved some drainages on the crests of rising antiforms. According to this hypothesis, corrugations were produced by folding after subacrial exposure of detachment-fault foot-walls. An alternative hypothesis, proposed here, is as follows. In a setting where preexisting drainages cross an active normal fault, each fault-slip event will cut each drainage into two segments separated by a freshly denuded fault ramp. The upper and lower drainage segments will remain hydraulically linked after each fault-slip event if the drainage in the hanging-wall block is incised, even if the stream is on the flank of an antiformal corrugation and there is a large component of strike-slip fault movement. Maintenance of hydraulic linkage during sequential fault-slip events will guide the lengthening stream down the fault ramp as the ramp is uncovered, and stream incision will form a progressively lengthening, extension-parallel, linear drainage segment. This mechanism for linear drainage genesis is compatible with corrugations as original irregularities of the detachment fault, and does not require folding after early to middle Miocene footwall exhumations. This is desirable because many drainages are incised into nonmylonitic crystalline footwall rocks that were probably not folded under low

A Digital 3D-Reconstruction of the Younger Dryas Baltic Ice Lake

NASA Astrophysics Data System (ADS)

Jakobsson, M.; Alm, G.; Bjorck, S.; Lindeberg, G.; Svensson, N.

2005-12-01

A digital 3D-reconstruction of the final stage of the ice dammed Baltic Ice Lake (BIL), dated to the very end of the Younger Dryas cold period (ca. 11 600 cal. yr BP) has been compiled using a combined bathymetric-topographic Digital Terrain Model (DTM), Scandinavian ice sheet limits, Baltic Sea Holocene bottom sediment thickness information, and a paleoshoreline database maintained at the Lund University. The combined bathymetric-topographic Digital Terrain Model (DTM) model used to reconstruct the ice dammed lake was compiled specifically for this study from publicly available data sets. The final DTM is in the form of a digital grid on Lamberts Equal Area projection with a resolution of 500 x 500 m, which permits a much more detailed reconstruction of the BIL than previously made. The lake was constructed through a series of experiments where mathematical algorithms were applied to fit the paleolake's surface through the shoreline database. The accumulated Holocene bottom sediments in the Baltic Sea were subsequently subtracted from the present bathymetry in our reconstruction. This allows us to estimate the Baltic Ice Lake's paleobathymetry, area, volume, and hypsometry, which will comprise key input data to lake/climate modeling exercises following this study. The Scandinavian ice sheet margin eventually retreated north of Mount Billingen, which was the high point in terrain of Southern central Sweden bordering to lower terrain further to the North. As a consequence, the BIL was catastrophically drained through this area, resulting in a 25 m drop of the lake level. With our digital BIL model we estimate that approximately 7, 800 km3 of water drained during this event and that the ice dammed lake area was reduced with ca 18 percent. The digital BIL reconstruction is analyzed using 3D-visualization techniques that provide new detailed information on the paleogeography in the area, both before and after the lake drainage, with implications for interpretations of

Geology and geomorphology of Bear Lake Valley and upper Bear River, Utah and Idaho

USGS Publications Warehouse

Reheis, M.C.; Laabs, B.J.C.; Kaufman, D.S.

2009-01-01

Bear Lake, on the Idaho-Utah border, lies in a fault-bounded valley through which the Bear River flows en route to the Great Salt Lake. Surficial deposits in the Bear Lake drainage basin provide a geologic context for interpretation of cores from Bear Lake deposits. In addition to groundwater discharge, Bear Lake received water and sediment from its own small drainage basin and sometimes from the Bear River and its glaciated headwaters. The lake basin interacts with the river in complex ways that are modulated by climatically induced lake-level changes, by the distribution of active Quaternary faults, and by the migration of the river across its fluvial fan north of the present lake. The upper Bear River flows northward for ???150 km from its headwaters in the northwestern Uinta Mountains, generally following the strike of regional Laramide and late Cenozoic structures. These structures likely also control the flow paths of groundwater that feeds Bear Lake, and groundwater-fed streams are the largest source of water when the lake is isolated from the Bear River. The present configuration of the Bear River with respect to Bear Lake Valley may not have been established until the late Pliocene. The absence of Uinta Range-derived quartzites in fluvial gravel on the crest of the Bear Lake Plateau east of Bear Lake suggests that the present headwaters were not part of the drainage basin in the late Tertiary. Newly mapped glacial deposits in the Bear River Range west of Bear Lake indicate several advances of valley glaciers that were probably coeval with glaciations in the Uinta Mountains. Much of the meltwater from these glaciers may have reached Bear Lake via groundwater pathways through infiltration in the karst terrain of the Bear River Range. At times during the Pleistocene, the Bear River flowed into Bear Lake and water level rose to the valley threshold at Nounan narrows. This threshold has been modified by aggradation, downcutting, and tectonics. Maximum lake

Enigmatic mounds in 'Subglacial Meltwater Corridors' on the Canadian Shield: a record of channelised, subglacial meltwater drainage during Laurentide deglaciation

NASA Astrophysics Data System (ADS)

Haiblen, Anna; Ward, Brent; Normandeau, Philippe; Campbell, Janet

2017-04-01

. SMCs likely formed late during deglaciation because the enigmatic mounds and eskers that they contain do not appear to have been significantly affected by ice flow following their deposition. We suggest that transient, sheet-type subglacial meltwater flow events resulted in erosion and transport of basal till. Meltwater was likely sourced from supraglacial lakes that formed and drained catastrophically when the ablation zone of the Laurentide Ice Sheet affected the area. The enigmatic mounds that we have observed near Lac de Gras may have been deposited from a slurry-type flow. Eskers likely formed later, after a channelised drainage system was established. It is possible that SMCs are the Quaternary landscape record of lake-drainage events similar to those that occur in Southwest Greenland today. The hydraulic conditions required to create enigmatic mounds are different to those required for esker formation. Thus, SMCs, not just the eskers that they sometimes contain, should be considered when parameters are developed for numerical models relating to subglacial drainage systems in shield terrains. Determining the genesis of landforms found within SMCs will improve our understanding of hydraulic conditions in the subglacial, channelised drainage system during ice-sheet retreat and decay.

Geothermal activity and hydrothermal mineral deposits at southern Lake Bogoria, Kenya Rift Valley: Impact of lake level changes

NASA Astrophysics Data System (ADS)

Renaut, Robin W.; Owen, R. Bernhart; Ego, John K.

2017-05-01

Lake Bogoria, a saline alkaline closed-lake in a drainage basin of Neogene volcanic rocks in the central Kenya Rift, is fed partly by ∼200 hot alkaline springs located in three groups along its margins. Hot springs along the midwest shoreline (Loburu, Chemurkeu) and their travertine deposits have been studied, but little is known about the geothermal activity at southern Lake Bogoria. Observations, field measurements and analyses (geochemical and mineralogical) of the spring waters and deposits, spanning three decades, show that the southern spring waters are more saline, the hydrothermal alteration there is more intense, and that most hot spring deposits are siliceous. Geothermal activity at southern Lake Bogoria (Ng'wasis, Koibobei, Losaramat) includes littoral boiling springs and geysers, with fumaroles at slightly higher elevations. Modern spring deposits are ephemeral sodium carbonates, opal-A crusts and silica gels. Local fossil spring deposits include diatomaceous silica-cemented conglomerates that formed subaqueously when the lake was then dilute and higher than today, and outlying calcite tufa deposits. In contrast, mineral deposits around neighbouring fumarole vents and sites of hydrothermal alteration include clays (kaolinite), sulfate minerals (jarosite, alunite), and Fe-oxyhydroxides linked to rising acidic fluids. When lake level falls, the zone of acidity moves downwards and may overprint older alkaline spring deposits. In contrast, rising lake level leads to lake water dilution and vents in the lower parts of the acidic zone may become dilute alkaline springs. The new evidence at Lake Bogoria shows the potential for using the mineralogy of geothermal sediments to indicate former changes in lake level.

Phosphorus availability in Western Lake Erie Basin drainage waters: legacy evidence across spatial scales

USDA-ARS?s Scientific Manuscript database

The Western Lake Erie Basin (WLEB) was inundated with precipitation during June and July 2015 (2-3× greater than historical averages), which led to significant nutrient loading and the largest in-lake algal bloom on record. Using discharge and concentration data from three spatial scales (0.09 km2 t...

Impacts of extreme weather events on highly eutrophic marine ecosystem (Rogoznica Lake, Adriatic coast)

NASA Astrophysics Data System (ADS)

Ciglenečki, I.; Janeković, I.; Marguš, M.; Bura-Nakić, E.; Carić, M.; Ljubešić, Z.; Batistić, M.; Hrustić, E.; Dupčić, I.; Garić, R.

2015-10-01

Rogoznica Lake is highly eutrophic marine system located on the Eastern Adriatic coast (43°32‧N, 15°58‧E). Because of the relatively small size (10,276 m2) and depth (15 m) it experiences strong natural and indirect anthropogenic influences. Dynamics within the lake is characterized by the extreme and highly variable environmental conditions (seasonal variations in salinity and temperature, water stratification and mixing, redox and euxinic conditions, concentrations of nutrients) which significantly influence the biology inside the lake. Due to the high phytoplankton activity, the upper part of the water column is well oxygenated, while hypoxia/anoxia usually occurs in the bottom layers. Anoxic part of the water column is characterized with high concentrations of sulfide (up to 5 mM) and nutrients (NH4+ up to 315 μM; PO43- up to 53 μM; SiO44- up to 680 μM) indicating the pronounced remineralization of the allochthonous organic matter, produced in the surface waters. The mixolimnion varies significantly within a season feeling effects of the Adriatic atmospheric and ocean dynamics (temperature, wind, heat fluxes, rainfall) which all affect the vertical stability and possibly induce vertical mixing and/or turnover. Seasonal vertical mixing usually occurs during the autumn/winter upon the breakdown of the stratification, injecting oxygen-rich water from the surface into the deeper layers. Depending on the intensity and duration of the vertical dynamics (slower diffusion and/or faster turnover of the water layers) anoxic conditions could developed within the whole water column. Extreme weather events such as abrupt change in the air temperature accompanied with a strong wind and consequently heat flux are found to be a key triggering mechanism for the fast turnover, introducing a large amount of nutrients and sulfur species from deeper parts to the surface. Increased concentration of nutrients, especially ammonium, phosphate, and silicates persisting for

Flexural-response of the McMurdo Ice Shelf to surface lake filling and drainage

NASA Astrophysics Data System (ADS)

Banwell, A. F.; MacAyeal, D. R.; Willis, I.; Macdonald, G. J.; Goodsell, B.

2017-12-01

Antarctic ice-shelf instability and break-up, as exhibited by the Larsen B ice shelf in 2002, remains one of the most difficult glaciological processes to observe directly. It is, however, vital to do so because ice-shelf breakup has the potential to influence the buttressing controls on inland ice discharge, and thus to affect sea level. Several mechanisms enabling Larsen B style breakup have previously been proposed, including the ability of surface lakes to introduce ice-shelf fractures when they fill and drain. During the austral summer of 2016/2017, we monitored the filling and draining of four surface lakes on the McMurdo Ice Shelf, Antarctica, and the effect of these processes on ice-shelf flexure. Water-depth data from pressure sensors reveal that two lakes filled to >2 m in depth and subsequently drained over multiple week timescales, which had a simultaneous effect on vertical ice deflection in the area. Differential GPS data from 12 receivers over three months show that vertical deflection varies as a function of distance from the maximum load change (i.e. at the lake centre). Using remote sensing techniques applied to both Landsat 8 and Worldview imagery, we also quantify the meltwater volume in these two lakes through the melt season, which, together with the vertical deflection data, are used to constrain key flexural parameter values in numerical models of ice-shelf flexure.

Late migration of a metal stent after EUS-drainage of a pancreatic pseudocyst abscess.

PubMed

Maldonado Pérez, Belén; Guerra Veloz, María Fernanda; Romero Castro, Rafael

2018-04-01

Endoscopic ultrasound (EUS)-guided drainage of pancreatic collections has replaced surgery as the first line of treatment due its accuracy and safety profile. A higher success rate and fewer adverse events has been observed using fully covered metal stent for the drainage. However, complications of EUS-guided drainage can appear. We present a case of late migration of the stent.

Consequences of an unusual flood event: case study of a drainage canal breach on a fluvial plain in NE Slovenia

NASA Astrophysics Data System (ADS)

Vidmar, Ines; Ambrožič, Bojan; Debeljak, Barbara; Dolžan, Erazem; Gregorin, Špela; Grom, Nina; Herman, Polona; Keršmanc, Teja; Mencin, Eva; Mernik, Natalija; Švara, Astrid; Trobec, Ana; Turnšek, Anita; Vodeb, Petra; Torkar, Anja; Brenčič, Mihael

2013-04-01

On November 4-6 2012 heavy precipitation resulted in floods in the middle and lower course of Drava River in NE Slovenia causing damage to many properties in the flooded area. The meteorological situation that led to consequent floods was characterized by high precipitation, fast snowmelt, SW wind and relatively high air temperature. The weather event was part of a cyclone which was spreading over the area of North, West and Central Europe in the direction of Central Europe and carried with it the passing of a cold front through Slovenia on November 4 and 5. The flood wave travelled on the Drava River from Austria to Slovenia past the 11 hydroelectric power plants after eventually moving over the Slovenian-Croatian border. The river discharge increased in the early morning of November 5 reaching 3165 m3/s. This work focuses on a single event in the Ptujsko polje where among other damage caused by the flooding, the river broke through the drainage canal of the Formin hydroelectric power plant and changed its course. The Ptujsko polje contains two fluvial terraces. In the area of Formin HPP, the lower terrace is 1.5 km wide and the surface as well as the groundwater gradient shift from west to east with the groundwater flowing parallel to the river. These characteristics contributed to the flooding and consequential breach in the embankment of the drainage canal. Several aspects of the recent floods are discussed including a critical reflection of data accessibility, possible causes and mechanisms behind it as well as the possibility of its forecasting. Synthesis of accessible data from open domain sources is performed with emphasis on geological conditions. Discharge and precipitation data from the data base of Slovenian Environment Agency are collected, reviewed and analyzed. The flood event itself is analyzed and described in detail. It is determined that the flood wave was different from the ones regulated by natural processes which points to an anthropogenic

Factors of ecologic succession in oligotrophic fish communities of the Laurentian Great Lakes

USGS Publications Warehouse

Smith, Stanford H.

1972-01-01

Oligotrophic fish communities of the Great Lakes have undergone successive disruptions since the mid-1800s. Major contributing factors have been intensive selective fisheries, extreme modification of the drainage, invasion of marine species, and progressive physical–chemical changes of the lake environments. Lake Ontario was the first to be affected as its basin was settled and industrialized earliest, and it was the first to be connected by canals to the mid-Atlantic where the alewife (Alosa pseudoharengus) and sea lamprey (Petromyzon marinus) which ultimately became established in the Great Lakes were abundant. Oligotrophic fish communities were successively disrupted in Lakes Erie, Huron, Michigan, and Superior as the affects of population growth, industrialization, and marine invaders spread upward in the Laurentian drainage.The degree and sequence of response of families offish and species within families differed for each factor, but the sequence of change among families and species has been the same in response to each factor as it affected various lakes at different times. The ultimate result of the disruption of fish communities has been a reduction of productivity of oligotrophic species that ranges from extreme in Lake Ontario to moderate in Lake Superior, and which has reached a state of instability and rapid change in the upper three Great Lakes by the rnid-1900s similar to the situation in Lake Ontario in the mid-1800s. Since oligotrophic species (primarily salmonines, coregonines, and deepwater cottids) are the only kinds of fish that fully occupied the entire volume of the deepwater Great Lakes (Ontario, Huron, Michigan, and Superior), the fish biomass of these lakes has been reduced as various species declined or disappeared. In Lake Erie, which is shallow, and in the shallow bays of the deep lakes, oligotrophic species were replaced by mesotrophic species, primarily percids, which have successively increased and declined. All oligotrophic

Detailed study of selenium in soil, water, bottom sediment, and biota in the Sun River Irrigation Project, Freezout Lake Wildlife Management Area, and Benton Lake National Wildlife Refuge, west-central Montana, 1990-92

USGS Publications Warehouse

Nimick, D.A.; Lambing, J.H.; Palawski, D.U.; Malloy, J.C.

1996-01-01

Selenium and other constituents are adversely affecting water quality and creating a potential hazard to wildlife in several areas of the Sun River Irrigation Project, Freezout Lake Wildlife Management Area, and Benton Lake National Wildlife Refuge in west-central Montana. Selenium derived from Cretaceous shale and Tertiary and Quaternary deposits containing shale detritus is transported in the oxic shallow ground-water systems. At Freezout Lake Wildlife Management Area, drainage from irrigated glacial deposits is the primary source of selenium; drainage from non-irrigated farmland is a significant source locally. Benton Lake generally receives more selenium from natural runoff from its non-irrigated basin than from the trans-basin diversion of irrigation return flow. Selenium has accumulated in aquatic plants and invertebrates, fish, and water birds, particularly in wetlands that receive the largest selenium loads. Although selenium residues in biological tissue from some wetland units exceeded biological risk levels, water-bird reproduction generally has not been impaired. The highest selenium residues in biota commonly occurred in samples from Priest Butte Lakes, which also had the highest selenium concentration in wetland water. Selenium concentrations in all invertebrate samples from Priest Butte Lakes and the south end of Freezeout Lake exceeded the critical dietary threshold for water birds. Selenium delivered to wetlands accumulates in bottom sediment, predominantly in near-shore areas. Potential impacts to water quality, and presumably biota, may be greatest near the mouths of inflows. Most selenium delivered to wetlands will continue to accumulate in bottom sediment and biota.

Water Quality, Hydrology, and Response to Changes in Phosphorus Loading of Nagawicka Lake, a Calcareous Lake in Waukesha County, Wisconsin

USGS Publications Warehouse

Garn, Herbert S.; Robertson, Dale M.; Rose, William J.; Goddard, Gerald L.; Horwatich, Judy A.

2006-01-01

Nagawicka Lake is a 986-acre, usually mesotrophic, calcareous lake in southeastern Wisconsin. Because of concern over potential water-quality degradation of the lake associated with further development in its watershed, a study was conducted by the U.S. Geological Survey from 2002 to 2006 to describe the water quality and hydrology of the lake; quantify sources of phosphorus, including those associated with urban development; and determine the effects of past and future changes in phosphorus loading on the water quality of the lake. All major water and phosphorus sources were measured directly, and minor sources were estimated to construct detailed water and phosphorus budgets for the lake. The Bark River, near-lake surface inflow, precipitation, and ground water contributed 74, 8, 12, and 6 percent of the inflow, respectively. Water leaves the lake primarily through the Bark River outlet (88 percent) or by evaporation (11 percent). The water quality of Nagawicka Lake has improved dramatically since 1980 as a result of decreasing the historical loading of phosphorus to the lake. Total input of phosphorus to the lake was about 3,000 pounds in monitoring year (MY) 2003 and 6,700 pounds in MY 2004. The largest source of phosphorus entering the lake was the Bark River, which delivered about 56 percent of the total phosphorus input, compared with about 74 percent of the total water input. The next largest contributions were from the urbanized near-lake drainage area, which disproportionately accounted for 37 percent of the total phosphorus input but only about 5 percent of the total water input. Simulations with water-quality models within the Wisconsin Lakes Modeling Suite (WiLMS) indicated the response of Nagawicka Lake to 10 phosphorus-loading scenarios. These scenarios included historical (1970s) and current (base) years (MY 2003-04) for which lake water quality and loading were known, six scenarios with percentage increases or decreases in phosphorus loading from

Water-quality characteristics of Michigan's inland lakes, 2001-10

USGS Publications Warehouse

Fuller, L.M.; Taricska, C.K.

2012-01-01

statistically significant difference was found at the 95-percent confidence level among historical nutrients and trophic characteristics when comparing 445 lakes with historical data for 1974–84 with the 2001–10 dataset, though SDT did show statistically significant differences at the 95-percent confidence level. Depending on the primary indicator, 50–66 percent of lakes did not change trophic-status class, 13–23 percent moved towards the oligotrophic end of the TSI scale, and 20–25 percent moved a class towards the eutrophic end of the TSI scale. Increasing percentages of urban-dominant land cover in the drainage areas of lakes had a more positive correlation with chloride concentration than did increased percentages of other land-cover classes; there was also a slight correlation of urban-dominant land cover and calcium concentration. Removing data for lakes in southeastern Lower Michigan, known from previous reports to be higher in chloride, still resulted in a positive relation even though the coefficient of determination (R2 value) decreased from 0.55 to 0.39. Dominant land-cover drainage areas were not strongly related to nutrients with respect to a linear relation, nor were lake drainage-area sizes.

Estimation of Tile Drainage Contribution to Streamflow and Nutrient Export Loads

NASA Astrophysics Data System (ADS)

Schilling, K. E.; Arenas Amado, A.; Jones, C. S.; Weber, L. J.

2015-12-01

Subsurface drainage is a very common practice in the agricultural U.S. Midwest. It is typically installed in poorly drained soils in order to enhance crop yields. The presence of tile drains creates a route for agrichemicals to travel and therefore negatively impacts stream water quality. This study estimated through end-member analyses the contributions of tile drainage, groundwater, and surface runoff to streamflow at the watershed scale based on continuously monitored data. Especial attention was devoted to quantifying tile drainage impact on watershed streamflow and nutrient export loads. Data analyzed includes streamflow, rainfall, soil moisture, shallow groundwater levels, in-stream nitrate+nitrite concentrations and specific conductance. Data were collected at a HUC12 watershed located in Northeast Iowa, USA. Approximately 60% of the total watershed area is devoted to agricultural activities and forest and grassland are the other two predominant land uses. Results show that approximately 20% of total annual streamflow comes from tile drainage and during rainfall events tile drainage contribution can go up to 30%. Furthermore, for most of the analyzed rainfall events groundwater responded faster and in a more dramatic fashion than tile drainage. The State of Iowa is currently carrying out a plan to reduce nutrients in Iowa waters and the Gulf of Mexico (Iowa Nutrient Reduction Strategy). The outcome of this investigation has the potential to assist in Best Management Practice (BMP) scenario selection and therefore help the state achieve water quality goals.

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

USGS Publications Warehouse

Jager, Stefan; Wieczorek, Gerald E.

1994-01-01

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

Climate change and the global pattern of moraine-dammed glacial lake outburst floods

NASA Astrophysics Data System (ADS)

Harrison, Stephan; Kargel, Jeffrey S.; Huggel, Christian; Reynolds, John; Shugar, Dan H.; Betts, Richard A.; Emmer, Adam; Glasser, Neil; Haritashya, Umesh K.; Klimeš, Jan; Reinhardt, Liam; Schaub, Yvonne; Wiltshire, Andy; Regmi, Dhananjay; Vilímek, Vít

2018-04-01

Despite recent research identifying a clear anthropogenic impact on glacier recession, the effect of recent climate change on glacier-related hazards is at present unclear. Here we present the first global spatio-temporal assessment of glacial lake outburst floods (GLOFs) focusing explicitly on lake drainage following moraine dam failure. These floods occur as mountain glaciers recede and downwaste. GLOFs can have an enormous impact on downstream communities and infrastructure. Our assessment of GLOFs associated with the rapid drainage of moraine-dammed lakes provides insights into the historical trends of GLOFs and their distributions under current and future global climate change. We observe a clear global increase in GLOF frequency and their regularity around 1930, which likely represents a lagged response to post-Little Ice Age warming. Notably, we also show that GLOF frequency and regularity - rather unexpectedly - have declined in recent decades even during a time of rapid glacier recession. Although previous studies have suggested that GLOFs will increase in response to climate warming and glacier recession, our global results demonstrate that this has not yet clearly happened. From an assessment of the timing of climate forcing, lag times in glacier recession, lake formation and moraine-dam failure, we predict increased GLOF frequencies during the next decades and into the 22nd century.

Utah: Salt Lake Region

Atmospheric Science Data Center

2014-05-15

... scheduled events are at city (indoor) locations, and five in mountain (outdoor) facilities. All ten can be found within the area contained ... Lake City is surrounded by mountains including the Wasatch Range to the east, and the temperature difference between the Great Salt Lake ...

Lake sediment records as earthquake catalogues: A compilation from Swiss lakes - Limitations and possibilities

NASA Astrophysics Data System (ADS)

Kremer, Katrina; Reusch, Anna; Wirth, Stefanie B.; Anselmetti, Flavio S.; Girardclos, Stéphanie; Strasser, Michael

2016-04-01

Intraplate settings are characterized by low deformation rates and recurrence intervals of strong earthquakes that often exceed the time span covered by instrumental records. Switzerland, as an example for such settings, shows a low instrumentally recorded seismicity, in contrast to strong earthquakes (e.g. 1356 Basel earthquake, Mw=6.6 and 1601 Unterwalden earthquake, Mw=5.9) mentioned in the historical archives. As such long recurrence rates do not allow for instrumental identification of earthquake sources of these strong events, and as intense geomorphologic alterations prevent preservation of surface expressions of faults, the knowledge of active faults is very limited. Lake sediments are sensitive to seismic shaking and thus, can be used to extend the regional earthquake catalogue if the sedimentary deposits or deformation structures can be linked to an earthquake. Single lake records allow estimating local intensities of shaking while multiple lake records can furthermore be used to compare temporal and spatial distribution of earthquakes. In this study, we compile a large dataset of dated sedimentary event deposits recorded in Swiss lakes available from peer-reviewed publications and unpublished master theses. We combine these data in order to detect large prehistoric regional earthquake events or periods of intense shaking that might have affected multiple lake settings. In a second step, using empirical seismic attenuation equations, we test if lake records can be used to reconstruct magnitudes and epicentres of identified earthquakes.

Salinity and hydrology of closed lakes

USGS Publications Warehouse

Langbein, Walter Basil

1961-01-01

Lakes without outlets, called closed lakes, are exclusively features of the arid and semiarid zones where annual evaporation exceeds rainfall. The number of closed lakes increases with aridity, so there are relatively few perennial closed lakes, but "dry" lakes that rarely contain water are numerous.Closed lakes fluctuate in level to a much greater degree than the open lakes of the humid zone, because variations in inflow can be compensated only by changes in surface area. Since the variability of inflow increases with aridity, it is possible to derive an approximate relationship for the coefficient of variation of lake area in terms of data on rates of evaporation, lake area, lake depth, and drainage area.The salinity of closed lakes is highly variable, ranging from less than 1 percent to over 25 percent by weight of salts. Some evidence suggests that the tonnage of salts in a lake solution is substantially less than the total input of salts into the lake over the period of existence of the closed lake. This evidence suggests further that the salts in a lake solution represent a kind of long-term balance between factors of gain and loss of salts from the solution.Possible mechanisms for the loss of salts dissolved in the lake include deposition in marginal bays, entrapment in sediments, and removal by wind. Transport of salt from the lake surface in wind spray is also a contributing, but seemingly not major, factor.The hypothesis of a long-term balance between input to and losses from the lake solution is checked by deriving a formula for the equilibrium concentration and comparing the results with the salinity data. The results indicate that the reported salinities seemingly can be explained in terms of their geometric properties and hydrologic environment.The time for accumulation of salts in the lake solution the ratio between mass of salts in the solution and the annual input may also be estimated from the geometric and hydrologic factors, in the absence of

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

Bacteria and Turbidity Survey for Blue Mountain Lake, Arkansas, Spring and Summer, 1994

USGS Publications Warehouse

Lasker, A. Dwight

1995-01-01

Introduction Blue Mountain Lake darn is located at river mile 74.4 on the Petit Jean River in Logan and Yell Counties in west-central Arkansas (fig. 1). Drainage area above the darn is 488 square miles. Blue Mountain Lake is located between two national forests-the Ozark National Forest and the Ouachita National Forest. The primary purpose for Blue Mountain Lake is flood control, but the lake is used for a variety of recreational purposes. The U.S. Geological Survey (USGS) in cooperation with the U.s. Army Corps of Engineers, Little Rock District, conducted a bacterial and turbidity study of the Blue Mountain Lake Basin during the spring and suri1mer 1994. Samples were collected weekly at 11 locations within the lake basin from May through September 1994. Eight sampling sites were located on tributaries to the lake and three sampling sites were located on the lake with one of the sites located at a swim beach (fig. 2; table 1).

Mass-movement and flood-induced deposits in Lake Ledro, southern Alps, Italy: implications for Holocene palaeohydrology and natural hazards

NASA Astrophysics Data System (ADS)

Simonneau, A.; Chapron, E.; Vannière, B.; Wirth, S. B.; Gilli, A.; Di Giovanni, C.; Anselmetti, F. S.; Desmet, M.; Magny, M.

2013-03-01

flash flood events during the Holocene was, however, not high enough to affect pedogenesis processes and highlight several wet regional periods during the Holocene. The Holocene period is divided into four phases of environmental evolution. Over the first half of the Holocene, a progressive stabilization of the soils present through the catchment of Lake Ledro was associated with a progressive reforestation of the area and only interrupted during the wet 8.2 event when the soil destabilization was particularly important. Lower soil erosion was recorded during the mid-Holocene climatic optimum (8000-4200 cal. yr BP) and associated with higher algal production. Between 4200 and 3100 cal. yr BP, both wetter climate and human activities within the drainage basin drastically increased soil erosion rates. Finally, from 3100 cal. yr BP to the present-day, data suggest increasing and changing human land use.

Crater Lake revealed

USGS Publications Warehouse

Ramsey, David W.; Dartnell, Peter; Bacon, Charles R.; Robinson, Joel E.; Gardner, James V.

2003-01-01

Around 500,000 people each year visit Crater Lake National Park in the Cascade Range of southern Oregon. Volcanic peaks, evergreen forests, and Crater Lake’s incredibly blue water are the park’s main attractions. Crater Lake partially fills the caldera that formed approximately 7,700 years ago by the eruption and subsequent collapse of a 12,000-foot volcano called Mount Mazama. The caldera-forming or climactic eruption of Mount Mazama drastically changed the landscape all around the volcano and spread a blanket of volcanic ash at least as far away as southern Canada.Prior to the climactic event, Mount Mazama had a 400,000 year history of cone building activity like that of other Cascade volcanoes such as Mount Shasta. Since the climactic eruption, there have been several less violent, smaller postcaldera eruptions within the caldera itself. However, relatively little was known about the specifics of these eruptions because their products were obscured beneath Crater Lake’s surface. As the Crater Lake region is still potentially volcanically active, understanding past eruptive events is important to understanding future eruptions, which could threaten facilities and people at Crater Lake National Park and the major transportation corridor east of the Cascades.Recently, the lake bottom was mapped with a high-resolution multibeam echo sounder. The new bathymetric survey provides a 2m/pixel view of the lake floor from its deepest basins virtually to the shoreline. Using Geographic Information Systems (GIS) applications, the bathymetry data can be visualized and analyzed to shed light on the geology, geomorphology, and geologic history of Crater Lake.

Drainage reversals in Mono Basin during the late pliocene and Pleistocene

USGS Publications Warehouse

Reheis, M.C.; Stine, S.; Sarna-Wojcicki, A. M.

2002-01-01

Mono Basin, on the eastern flank of the central Sierra Nevada, is the highest of the large hydrographically closed basins in the Basin and Range province. We use geomorphic features, shoreline deposits, and basalt-filled paleochannels to reconstruct an early to middle Pleistocene record of shorelines and changing spillways of Lake Russell in Mono Basin. During this period of time, Lake Russell repeatedly attained altitudes between 2205 and 2280 m-levels far above the present surface of Mono Lake (~1950 m) and above its last overflow level (2188 m). The spill point of Lake Russell shifted through time owing to late Tertiary and Quaternary faulting and volcanism. During the early Pleistocene, the lake periodically discharged through the Mount Hicks spillway on the northeastern rim of Mono Basin and flowed northward into the Walker Lake drainage basin via the East Walker River. Paleochannels recording such discharge were incised prior to 1.6 Ma, possibly between 1.6 and 1.3 Ma, and again after 1.3 Ma (ages of basaltic flows that plugged the paleochannels). Faulting in the Adobe Hills on the southeastern margin of the basin eventually lowered the rim in this area to below the altitude of the Mount Hicks spillway. Twice after 0.76 Ma, and possibly as late as after 0.1 Ma, Lake Russell discharged southward through the Adobe Hills spillway into the Owens-Death Valley system of lakes. This study supports a pre-Pleistocene aquatic connection through Mono Basin between the hydrologically distinct Lahontan and Owens-Death Valley systems, as long postulated by biologists, and also confirms a probable link during the Pleistocene for species adapted to travel upstream in fast-flowing water.

Surface-water quality in rivers and drainage basins discharging to the southern part of Hood Canal, Mason and Kitsap Counties, Washington, 2004

USGS Publications Warehouse

Frans, L.M.; Paulson, A.J.; Huffman, R.L.; Osbourne, S.N.

2006-01-01

were highest at site S2b (0.49 mg/L), and dissolved organic carbon concentrations (3.3 mg/L) were highest at the outlet of Lake Devereaux. However, the overall impact of these sites on the nutrient loading to Hood Canal probably is negligible because of the low streamflow and small loads. Springtime samples were collected from the Union River, Tahuya River, Mission Creek, and three smaller drainage basins in March 2004. Samples were collected during spring rain events to determine if increased runoff contributes larger amounts of sediment and nutrients from the land into the surface water. There was little difference in nutrient concentrations between samples collected in the spring and base-flow samples collected in the summer. This is likely due to the fact that the springtime samples were collected during a rain event and not necessarily during a peak in the hydrograph.

Glacial Lake Lind, Wisconsin and Minnesota

USGS Publications Warehouse

Johnson, M.D.; Addis, K.L.; Ferber, L.R.; Hemstad, C.B.; Meyer, G.N.; Komai, L.T.

1999-01-01

Glacial Lake Lind developed in the pre-late Wisconsinan St. Croix River valley, Minnesota and Wisconsin, and lasted more than 1000 yr during the retreat of the Superior lobe at the end of the Wisconsinan glaciation. Lake Lind sediment consists primarily of red varved silt and clay, but also includes mud-flow deposits, nearshore silt (penecontemporaneously deformed in places), nearshore rippled sand, and deltaic sand. Lake Lind varved red clay is not part of glacial Lake Grantsburg, as suggested by earlier authors, because the red varves are separated from overlying glacial Lake Grantsburg silt and clay by a unit of deltaic and fluvial sand. Furthermore, varve correlations indicate that the base of the red varves is younger to the north, showing that the basin expanded as the Superior lobe retreated and was not a lake basin dammed to the southwest by the advancing Grantsburg sublobe. Varve correlations indicate that the Superior lobe retreated at a rate of about 200 m/yr. Uniform winter-clay thickness throughout most of the varve couplets suggests thermal stratification in the lake with clay trapped in the epilimnion; some clay would exit the lake at the outlet prior to winter freeze. Zones of thicker winter-clay layers, in places associated with mud-flow layers, indicate outlet incision, lake-level fall, and shoreline erosion and resuspension of lake clay. The most likely outlet for glacial Lake Lind was in the southwest part of the lake near the present site of Minneapolis, Minnesota. Nearshore sediment indicates that the lake level of glacial Lake Lind was around 280 m. The elevation of the base of the Lake Lind sediments indicates water depth was 20 to 55 m. Evidence in the southern part of the lake basin suggests that the Superior lobe readvanced at least once during the early stages of glacial Lake Lind. Lake Lind ended not by drainage but by being filled in by prograding deltas and outwash plains composed of sand derived from the retreating Superior lobe. It

Drainage of malignant ascites: patient selection and perspectives

PubMed Central

Stukan, Maciej

2017-01-01

Malignant ascites (MA) is a sign of advanced cancer and poor prognosis. MA can result in impairment in quality of life (QOL) and significant symptoms. As a supportive treatment, ascites can be drained by paracentesis (PC), percutaneously implanted catheters (tunneled, untunneled, central venous catheters), or peritoneal ports, or peritoneovenous shunts. The aim of this study was to evaluate the effectiveness, safety, and patient-reported outcomes (PRO) of different drainage methods for the management of MA. A systematic review of the literature was performed, and 32 original articles met the inclusion criteria. Patients selected for permanent drain insertion demonstrated symptoms related to MA and had undergone repeated PC. The primary focus of the reviewed articles was procedural safety issues. The rate of technical success of drainage device installation was 100%. Most patients experienced improvements in symptom control after ascites drainage. When analyzed together, 19.7% (255/1297) of patients experienced any complication and 6.2% (81/1297) experienced serious adverse events during MA drainage. Complications were reported for every drainage method; however, the least occurred after PC or central venous catheter, while the most serious occurred after peritoneovenous shunts. Adverse events were as follows: catheter obstruction: 4.4%, infection: 4.1%, leakage: 3.5%, catheter dislodgment: 2.3%, hypotension: 0.6%, injuries during device insertion: 0.6%, renal impairment: 0.5%, electrolyte imbalance: 0.2%, other: 3.6%. PRO and QOL endpoints were available for 12 studies. When PRO were measured using an interview, a significant improvement in symptom control and QOL was reported in almost all patients. Once standardized questionnaires were used, improvements in symptomatic scores and role functioning were observed. Deterioration was observed in cognitive and emotional subscales. MA drainage is a safe and effective method to control symptoms associated with ascites

Lake Erie: Effects of exploitation, environmental changes and new species on the fishery resources

USGS Publications Warehouse

Hartman, Wilbur L.

1972-01-01

In no other lake as large as Lake Erie (surface area, 25,690 km2) have such extensive changes taken place in the drainage basin, the lake environment, and the fish populations over the last 100 years. Deforestation and prairie burning led to erosion and siltation of valuable spawning grounds. Marsh spawning areas were drained. Lake-to-river spawning migrations were blocked by mill dams. Accelerated cultural nutrient loading increased total dissolved solids by nearly 50% (1920-70). Average summer water temperatures increased 1.1 C. Phytoplankton and zooplankton abundance increased severalfold. Severe oxygen depletion developed in the bottom waters of all three basins of the lake. Lake sturgeon were fished out as nuisance fish in the late 1800s. The commercial fisheries for lake trout, lake whitefish, and lake herring collapsed by 1940 and those for blue pike and walleye by 1960. Yellow perch production became unstable in the 1960s. The effects of exploitation, environmental changes, and new species on these fish populations are discussed.

Late Pleistocene outburst flooding from pluvial Lake Alvord into the Owyhee River, Oregon

USGS Publications Warehouse

Carter, D.T.; Ely, L.L.; O'Connor, J. E.; Fenton, C.R.

2006-01-01

At least one large, late Pleistocene flood traveled into the Owyhee River as a result of a rise and subsequent outburst from pluvial Lake Alvord in southeastern Oregon. Lake Alvord breached Big Sand Gap in its eastern rim after reaching an elevation of 1292 m, releasing 11.3 km3 of water into the adjacent Coyote Basin as it eroded the Big Sand Gap outlet channel to an elevation of about 1280 m. The outflow filled and then spilled out of Coyote Basin through two outlets at 1278 m and into Crooked Creek drainage, ultimately flowing into the Owyhee and Snake Rivers. Along Crooked Creek, the resulting flood eroded canyons, stripped bedrock surfaces, and deposited numerous boulder bars containing imbricated clasts up to 4.1 m in diameter, some of which are located over 30 m above the present-day channel. Critical depth calculations at Big Sand Gap show that maximum outflow from a 1292- to 1280-m drop in Lake Alvord was ??? 10,000 m3 s- 1. Flooding became confined to a single channel approximately 40 km downstream of Big Sand Gap, where step-backwater calculations show that a much larger peak discharge of 40,000 m3 s- 1 is required to match the highest geologic evidence of the flood in this channel. This inconsistency can be explained by (1) a single 10,000 m3 s- 1 flood that caused at least 13 m of vertical incision in the channel (hence enlarging the channel cross-section); (2) multiple floods of 10,000 m3 s- 1 or less, each producing some incision of the channel; or (3) an earlier flood of 40,000 m3 s- 1 creating the highest flood deposits and crossed drainage divides observed along Crooked Creek drainage, followed by a later 10,000 m3 s- 1 flood associated with the most recent shorelines in Alvord and Coyote Basins. Well-developed shorelines of Lake Alvord at 1280 m and in Coyote Basin at 1278 m suggest that after the initial flood, postflood overflow persisted for an extended period, connecting Alvord and Coyote Basins with the Owyhee River of the Columbia River

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).

Spatial characterization of acid rain stress in Canadian Shield Lakes

NASA Technical Reports Server (NTRS)

Tanis, Fred J.

1987-01-01

The acidification of lake waters from airborne pollution is of continental proportions both in North America and Europe. A major concern of the acid rain problem is the cumulative ecosystem damage to lakes and forest. The number of lakes affected in northeastern U.S. and on the Canadian Shield is though to be enormous. How seasonal changes in lake transparency are related to annual acidic load was examined. The relationship between variations in lake acidification and ecophysical units was also examined. The utility of Thematic Mapper based observations to measure seasonal changes in the optical transparency in acid lakes was investigated. The potential for this optical response is related to a number of local ecophysical factors with bedrock geology being, perhaps, the most important. Other factors include sulfate deposition, vegetative cover, and terrain drainage/relief. The area of southern Ontario contains a wide variety of geologies from the most acid rain sensitive granite quartzite types to the least sensitive limestone dolomite sediments. Annual sulfate deposition ranges from 1.0 to 4.0 grams/sq m.

Carbon and hydrogen isotope composition of plant biomarkers from lake sediments as proxies for precipitation changes across Heinrich Events in the subtropics

NASA Astrophysics Data System (ADS)

Arnold, T. E.; Diefendorf, A. F.; Brenner, M.; Freeman, K. H.; Curtis, J. H.

2015-12-01

Lake Tulane is a relatively deep (~23 m) solution lake in south-central Florida. Its depth and location on a structural high, the Lake Wales Ridge, enabled continuous lacustrine sediment accumulation over the past >60,000 years. Pollen in the lake sediments indicate repeated major shifts in the vegetation community, with six peaks in Pinus (pine) abundance that coincide with the most intense cold phases of Dansgaard-Oeschger cycles and the Heinrich events that terminate them. Alternating with Pinus peaks are zones with high relative percentages of Quercus (oak), Ambrosia (ragweed), Lyonia (staggerbush) and Ceratiola (rosemary) pollen, genera that today occupy the most xeric sites on the Florida landscape. This suggests the pollen record indicates the Pinus phases, and therefore Heinrich Events, were wetter than the intervening Quercus phases. To test the connection between Heinrich Events and precipitation in Florida, we analyzed the carbon (δ13C) and hydrogen (δD) isotope signatures of plant biomarkers extracted from the Lake Tulane sediment core as proxies of paleohydrology. The δ13C of plant biomarkers, such as n-alkanes and terpenoids, are determined, in part, by changes in water-use efficiency (WUE = Assimilation/Transpiration) in plant communities, which changes in response to shifts in mean annual precipitation. Plant δ13C values can, therefore, provide a rough indication of precipitation changes when other factors, such as plant community, are relatively stable throughout time. Paleohydrology is also recorded in the δD of plant leaf waxes, which are strongly controlled by precipitation δD. In this region, precipitation δD is negatively correlated with rainfall amount (i.e. the "amount" effect) and positively correlated with aridity. Thus, the δ13C and δD signatures of molecular plant biomarkers provide relative indicators of precipitation change, and when combined, provide a test of our hypothesis that vegetation changes in this region are driven

Sediments Exposed by Drainage of a Collapsing Glacier-Dammed Lake Show That Contemporary Summer Temperatures and Glacier Retreat Exceed the Medieval Warm Period in Southern Alaska

NASA Astrophysics Data System (ADS)

Loso, M. G.; Anderson, R. S.; Anderson, S. P.; Reimer, P. J.

2007-12-01

In the mountains of southcentral Alaska, recent and widespread glacier retreat is well-documented, but few instrumental or proxy records of temperature are available to place recent changes in a long-term context. The Medieval Warm Period in particular, is poorly documented because subsequent Little Ice Age glacier advances destroyed much of the existing sedimentary record. In a rare exception, sudden and unexpected catastrophic drainage of a previously stable glacier-dammed lake recently revealed lacustrine stratigraphy that spans over 1500 years. Located near the Bagley Icefield in Wrangell-St. Elias National Park and Preserve, Iceberg Lake first drained in A.D. 1999 and has not regained a stable shoreline since that time. Rapid incision of the exposed lakebed provided subaerial exposure of annual laminations (varves, confirmed by radiogenic evidence) that record continuous sediment deposition from A.D. 442 to A.D. 1998. We present a recalculated master chronology of varve thickness that combines measurements from several sites within the former lake. Varve thickness in this chronology is positively correlated with northern hemisphere temperature trends and also with a local, ~600 year long tree ring width chronology. Varve thickness increases in warm summers because of higher melt, runoff, and sediment transport, and also because shrinkage of the glacier dam allows shoreline regression that concentrates sediment in the smaller lake. Relative to the entire record, varve thicknesses and implied summer temperatures were lowest around A.D. 600, high between A.D. 1000 and A.D. 1300, low between A.D. 1500 and A.D 1850, and highest in the late 20th century. Combined with stratigraphic evidence that contemporary jokulhlaups are unprecedented since at least A.D. 442, this record suggests that late 20th century warming was more intense, and accompanied by more extensive glacier retreat, than the Medieval Warm Period or any other time in the last 1500 years. We emphasize

Potential strategies for recovery of lake whitefish and lake herring stocks in eastern Lake Erie

USGS Publications Warehouse

Oldenburg, K.; Stapanian, M.A.; Ryan, P.A.; Holm, E.

2007-01-01

Lake Erie sustained large populations of ciscoes (Salmonidae: Coregoninae) 120 years ago. By the end of the 19th century, abundance of lake whitefish (Coregonus clupeaformis) had declined drastically. By 1925, the lake herring (a cisco) population (Coregonus artedii) had collapsed, although a limited lake herring fishery persisted in the eastern basin until the 1950s. In the latter part of the 20th century, the composition of the fish community changed as oligotrophication proceeded. Since 1984, a limited recovery of lake whitefish has occurred, however no recovery was evident for lake herring. Current ecological conditions in Lake Erie probably will not inhibit recovery of the coregonine species. Recovery of walleye (Sander vitreus) and efforts to rehabilitate the native lake trout (Salvelinus namaycush) in Lake Erie will probably assist recovery because these piscivores reduce populations of alewife (Alosa psuedoharengus) and rainbow smelt (Osmerus mordax), which inhibit reproductive success of coregonines. Although there are considerable spawning substrates available to coregonine species in eastern Lake Erie, eggs and fry would probably be displaced by storm surge from most shoals. Site selection for stocking or seeding of eggs should consider the reproductive life cycle of the stocked fish and suitable protection from storm events. Two potential sites in the eastern basin have been identified. Recommended management procedures, including commercial fisheries, are suggested to assist in recovery. Stocking in the eastern basin of Lake Erie is recommended for both species, as conditions are adequate and the native spawning population in the eastern basin is low. For lake herring, consideration should be given to match ecophenotypes as much as possible. Egg seeding is recommended. Egg seeding of lake whitefish should be considered initially, with fingerling or yearling stocking suggested if unsuccessful. Spawning stocks of whitefish in the western basin of Lake

Climate Change Adaptation Decision Making for Glacial Lake Outburst Floods From Palcacocha Lake in Peru

NASA Astrophysics Data System (ADS)

Cuellar, A. D.; McKinney, D. C.

2014-12-01

Climate change has accelerated glacial retreat in high altitude glaciated regions of Peru leading to the growth and formation of glacier lakes. Glacial lake outburst floods (GLOF) are sudden events triggered by an earthquake, avalanche into the lake or other shock that causes a sudden outflow of water. These floods are catastrophic because of their sudden onset, the difficulty predicting them, and enormous quantity of water and debris rapidly flooding downstream areas. Palcacocha Lake in the Peruvian Andes has experienced accelerated growth since it burst in 1941 and threatens the major city of Huaraz and surrounding communities. Since the 1941 flood stakeholders have advocated for projects to adapt to the increasing threat posed by Palcacocha Lake. Nonetheless, discussions surrounding projects for Palcacocha have not included a rigorous analysis of the potential consequences of a flood, probability of an event, or costs of mitigation projects. This work presents the first step to rationally analyze the risks posed by Palcacocha Lake and the various adaptation projects proposed. In this work the authors use decision analysis to asses proposed adaptation measures that would mitigate damage in downstream communities from a GLOF. We use an existing hydrodynamic model of the at-risk area to determine how adaptation projects will affect downstream flooding. Flood characteristics are used in the HEC-FIA software to estimate fatalities and injuries from an outburst flood, which we convert to monetary units using the value of a statistical life. We combine the monetary consequences of a GLOF with the cost of the proposed projects and a diffuse probability distribution for the likelihood of an event to estimate the expected cost of the adaptation plans. From this analysis we found that lowering the lake level by 15 meters has the least expected cost of any proposal despite uncertainty in the effect of lake lowering on flooding downstream.

Characteristics of Drainage Divide Migration through Coseismic and Storm-Triggered Landslides

NASA Astrophysics Data System (ADS)

Dahlquist, M. P.; West, A. J.; Li, G.

2016-12-01

Drainage basin reorganization is a fundamental but poorly understood process in landscape evolution. Capture and loss of drainage area by rivers redistributes erosive power and can drive the response of a landscape to tectonic/climatic forcing. Evidence of discrete capture of tributaries is widespread and common, but study of gradual migration of divides by hillslope processes (e.g. landsliding) has been minimal. Much scholarship is devoted to the geometric characteristics of rivers as they respond to tectonic forces, and divide migration has been proposed to result from contrasts in fluvial channel form. However, fluvial processes do not extend to basin divides, so fluvial controls on drainage reorganization should be mediated by hillslope processes such as slope failure. Here we explore whether the mediating role of hillslopes can be observed over the timescale of a single earthquake or major storm. We examine landslides in steep landscapes caused by three major events in the past decade: the 2008 Mw 7.9 Wenchuan earthquake in Sichuan, China, the 2009 Typhoon Morakot in Taiwan, and the 2015 Mw 7.8 Gorkha earthquake in Nepal. These events generated landslides that cut off ridges, causing area gain and loss in the drainage basins outlined by those ridges. We compare the location of these ridge-cutting landslides to values of Χ, an integral value of upstream drainage area over the length of a river. Comparing the Χ values of rivers which share a drainage divide is thought to show which river is likely to gain area at the expense of the other as the divide migrates, defining an "aggressor" (smaller Χ at divide) and a "victim" (greater Χ). We compute Χ for the rivers draining ridge-cutting landslides and consider whether landslides favor drainage area gain in basins with lower X values. Our preliminary results suggest that divide migration in areas with small to moderate disparities in Χ appears to be stochastic, with divides frequently migrating in the opposite

Data Assimilation to Improve CMAQ Model Estimates of Particulate Matter Pollution during Wintertime Persistent Cold Air Pool Events in Salt Lake City, Utah

NASA Astrophysics Data System (ADS)

Ivey, C. E.; Balachandran, S.; Russell, A. G.; Hu, Y.; Holmes, H.

2017-12-01

More than one million people live in Salt Lake Valley, Utah, where wintertime pollution reaches unhealthy levels due to the unique meteorology and orography of the region. Persistent cold air pool (PCAP) events occur when high pressure ridges create stagnant conditions over a valley, which hampers large-scale advection and reduces surface wind speeds. During PCAP periods the fraction of incoming solar radiation that reaches the valley floor is also reduced, leading to temperature inversions that allow pollution to build. Pollution levels continue to climb until a washout event removes the pollutants from the valley. Washout events include high winds or precipitation events with advection or wet deposition related removal processes, respectively. In this work, novel data assimilation and source apportionment techniques are applied for January and February 2007 to analyze CMAQ-modeled source composition and source impacts for the Salt Lake Valley during PCAP events. First, a hybrid source-oriented apportionment model is applied over continental U.S. to determine observation and model-based impacts from 20 sources, including agricultural activities, fossil fuel combustion, dust, and metals processing. Then, a secondary bias correction method is applied to better quantify the source impacts on secondary PM2.5, which constitutes the majority of the PM2.5 mass. Revised concentrations reflect what was previously reported in studies of PCAP pollution in the Salt Lake Valley, where the dominant aerosol was found to be ammonium nitrate. Further, gasoline and natural gas combustion were found to be the greatest contributing sources to aerosol concentrations during the PCAP events. The benefit of the data assimilation methods is the availability of spatially and temporally resolved model estimates of source impacts that better reflect observed concentrations.

Whiting in Lake Michigan

NASA Technical Reports Server (NTRS)

2002-01-01

Satellites provide a view from space of changes on the Earth's surface. This series of images from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) aboard the Orbview-2 satellite shows the dramatic change in the color of Lake Michigan during the summer. The bright color that appears in late summer is probably caused by calcium carbonate-chalk-in the water. Lake Michigan always has a lot of calcium carbonate in it because the floor of the lake is limestone. During most of the year the calcium carbonate remains dissolved in the cold water, but at the end of summer the lake warms up, lowering the solubility of calcium carbonate. As a result, the calcium carbonate precipitates out of the water, forming clouds of very small solid particles that appear as bright swirls from above. The phenomenon is appropriately called a whiting event. A similar event occured in 1999, but appears to have started later and subsided earlier. It is also possible that a bloom of the algae Microcystis is responsible for the color change, but unlikely because of Lake Michigan's depth and size. Microcystis blooms have occured in other lakes in the region, however. On the shore of the lake it is possible to see the cities of Chicago, Illinois, and Milwaukee, Wisconsin. Both appear as clusters of gray-brown pixels. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

Extreme Flood Events Over the Past 300 Years Recorded in the Sediments of a Mountain Lake in the Altay Mountains, Northwestern China

NASA Astrophysics Data System (ADS)

Wu, J.; Zhou, J.; Shen, B.; Zeng, H.

2017-12-01

Global climate change has the potential to accelerate the hydrological cycle, which may further enhance the temporal frequency of regional extreme floods. Climatic models predict that intra-annual rainfall variability will intensify, which will shift current rainfall regimes towards more extreme systems with lower precipitation frequencies, longer dry periods, and larger individual precipitation events worldwide. Understanding the temporal variations of extreme floods that occur in response to climate change is essential to anticipate the trends in flood magnitude and frequency in the context of global warming. However, currently available instrumental data are not long enough for capturing the most extreme events, thus the acquisition of long duration datasets for historical floods that extend beyond available instrumental records is clearly an important step in discerning trends in flood frequency and magnitude with respect to climate change. In this study, a reconstruction of paleofloods over the past 300 years was conducted through an analysis of grain sizes from the sediments of Kanas Lake in the Altay Mountains of northwestern China. Grain parameters and frequency distributions both demonstrate that two abrupt environment changes exist within the lake sedimentary sequence. Based on canonical discriminant analysis (CDA) and C-M pattern analysis, two flood events corresponding to ca. 1760 AD and ca. 1890 AD were identified, both of which occurred during warmer and wetter climate conditions according to tree-ring records. These two flood events are also evidenced by lake sedimentary records in the Altay and Tianshan areas. Furthermore, through a comparison with other records, the flood event in ca. 1760 AD seems to have occurred in both the arid central Asia and the Alps in Europe, and thus may have been associated with changes in the North Atlantic Oscillation (NAO) index.

Effects of recharge from drainage wells on quality of water in the Floridan Aquifer in the Orlando area, central Florida

USGS Publications Warehouse

Schiner, G.R.; German, E.R.

1983-01-01

Approximately 400 drainage wells in the Orlando area inject, by gravity, large quantities of stormwater runoff that may or may not be suitable for most purposes without treatment into the same freshwater zones of the Floridan aquifer tapped for public supply. The wells are used mostly to control lake levels and dispose of urban storm runoff. Recharge from drainage wells compensates for heavy withdrawals from the Floridan aquifer and helps maintain aquifer pressures that retard upward saltwater encroachment. Sixty-five supply wells and 21 drainage wells within a 16-mile radius of Orlando were sampled from September 1977 to June 1979. Most constituent concentrations were slightly higher in water from drainage wells than in water from supply wells. The most notable differences were in bacteria colony count and total nitrogen concentrations. With the exception of bacteria, water from drainage wells would generally meet the maximum contaminant levels established by the National Interim Primary and Proposed Secondary Drinking Water Regulations. (USGS)

Spatial distribution and temporal development of high-mountain lakes in western Austria

NASA Astrophysics Data System (ADS)

Merkl, Sarah; Emmer, Adam; Mergili, Martin

2015-04-01

Glacierized high-mountain environments are characterized by active morphodynamics, favouring the rapid appearance and disappearance of lakes. On the one hand, such lakes indicate high-mountain environmental changes such as the retreat of glaciers. On the other hand, they are sometimes susceptible to sudden drainage, leading to glacial lake outburst floods (GLOFs) putting the downstream population at risk. Whilst high-mountain lakes have been intensively studied in the Himalayas, the Pamir, the Andes or the Western Alps, this is not the case for the Eastern Alps. A particular research gap, which is attacked with the present work, concerns the western part of Austria. We consider a study area of approx. 6,140 km², covering the central Alps over most of the province of Tyrol and part of the province of Salzburg. All lakes ≥250 m² located higher than 2000 m asl are mapped from high-resolution Google Earth imagery and orthophotos. The lakes are organized into seven classes: (i) ice-dammed; near-glacial (ii) moraine-dammed and (iii) bedrock-dammed; (iv) moraine-dammed and (v) bedrock-dammed distant to the recent glaciers; (vi) landslide-dammed; (vii) anthropogenic. The temporal development of selected lakes is investigated in detail, using aerial photographs dating back to the 1950s. 1045 lakes are identified in the study area. Only eight lakes are ice-dammed (i). One third of all lakes is located in the immediate vicinity of recent glacier tongues, half of them impounded by moraine (ii), half of them by bedrock (iii). Two thirds of all lakes are impounded by features (either moraines or bedrock) shaped by LIA or Pleistocenic glaciers at some distance to the present glacier tongues (iv and v). Only one landslide-dammed lake (vi) is identified in the study area, whilst 21 lakes are of anthropogenic origin (vii). 72% of all lakes are found at 2250-2750 m asl whilst less than 2% are found above 3000 m asl. The ratio of rock-dammed lakes increases with increasing

Tile drainage phosphorus loss with long-term consistent cropping systems and fertilization.

PubMed

Zhang, T Q; Tan, C S; Zheng, Z M; Drury, C F

2015-03-01

Phosphorus (P) loss in tile drainage water may vary with agricultural practices, and the impacts are often hard to detect with short-term studies. We evaluated the effects of long-term (≥43 yr) cropping systems (continuous corn [CC], corn-oats-alfalfa-alfalfa rotation [CR], and continuous grass [CS]) and fertilization (fertilization [F] vs. no-fertilization [NF]) on P loss in tile drainage water from a clay loam soil over a 4-yr period. Compared with NF, long-term fertilization increased concentrations and losses of dissolved reactive P (DRP), dissolved unreactive P (DURP), and total P (TP) in tile drainage water, with the increments following the order: CS > CR > CC. Dissolved P (dissolved reactive P [DRP] and dissolved unreactive P [DURP]) was the dominant P form in drainage outflow, accounting for 72% of TP loss under F-CS, whereas particulate P (PP) was the major form of TP loss under F-CC (72%), F-CR (62%), NF-CS (66%), NF-CC (74%), and NF-CR (72%). Dissolved unreactive P played nearly equal roles as DRP in P losses in tile drainage water. Stepwise regression analysis showed that the concentration of P (DRP, DURP, and PP) in tile drainage flow, rather than event flow volume, was the most important factor contributing to P loss in tile drainage water, although event flow volume was more important in PP loss than in dissolved P loss. Continuous grass significantly increased P loss by increasing P concentration and flow volume of tile drainage water, especially under the fertilization treatment. Long-term grasslands may become a significant P source in tile-drained systems when they receive regular P addition. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

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

Water budgets of Italian and Dutch gravel pit lakes: a study using a fen as a natural evaporation pan, stable isotopes and conservative tracer modeling.

NASA Astrophysics Data System (ADS)

Nella Mollema, Pauline; Antonellini, Marco

2015-04-01

Gravel pits are excavated in aquifers to fulfill the need for construction materials. Flow-through lakes form where the gravel pits are below the water table and fill with groundwater. Their presence changes the drainage patterns, water- and hydrochemical budgets of a watershed. We have studied the water budget of two gravel pit lakes systems using stable H and O isotopes of water as well as conservative tracer (Cl) modeling. The Dutch gravel pit lakes are a fluvial fresh water system of 70 lakes along the Meuse River and the Italian gravel pit lakes are a brackish system along the Adriatic coast. Surface water evaporation from the gravel pit lakes is larger than the actual evapotranspiration of the grass land and forests that were replaced. The ratio of evaporation to total flow into the Dutch lakes was determined by using a Fen as a natural evaporation pan: the isotope content of the Tuspeel Fen, filled with rain water and sampled in a dry and warm summer period (August 2012), is representative for the limiting isotopic enrichment under local hydro meteorological conditions. The Local Evaporation line (LEL) was determined δ2 H = 4.20 δ 18O - 14.10 (R² = 0.99) and the ratio of total inflow to evaporation for three gravel pit lakes were calculated to be 22.6 for the De Lange Vlieter lake used for drinking water production, 11.3 for the Boschmolen Lake and 8.9 for the Anna's Beemd lake showing that groundwater flow is much larger than evaporation. The Italian gravel pit lakes are characterized by high salinity (TDS = 4.6-12.3 g L-1). Stable isotope data show that these latter gravel pit lakes are fed by groundwater, which is a mix between fresh Apennine River water and brackish (Holocene) Adriatic Sea water. The local evaporation line is determined: δ2H = 5.02 δ18O - 10.49. The ratio of total inflow to evaporation is 5. Conservative tracer modeling indicates that the chloride concentration in the Italian gravel pit lakes stabilizes after a short period of rapid

[Construct of Yangtze-Huai River rural areas ecological drainage system and its retention effect on pollutants].

PubMed

Shan, Bao-Qing; Li, Nan; Tang, Wen-Zhong

2012-11-01

Ecological drainage system (EDS) including ditches, ponds and wetland was constructed at the Paifangchen village on the north of Chaohu Lake, Anhui, and its retention effect on pollution was investigated. With the comprehensive function of sewage discharge, collecting and process, the system could intercept runoff pollutants effectively. The results acquired from 3 rainfall events showed that the retention rates of EDS to TSS, COD, TP and TN were 78.2%, 57.8%, 55.5% and 64.2% respectively, and the concentrations at outflow of the system to TSS, COD, TP and NH4(+) -N were 23.5, 66.3, 0.49 and 3.03 mg x L(-1) separately, met the first standard of "Integrated Wastewater Discharge Standards". Ponds were the important unit of EDS and the daily water quality concentrations of TSS, COD, TP and TN were 28.0, 31.2, 0.47 and 4.65 mg x L(-1) respectively, met the V standard of "Environment Quality Standards for Surface Water" basically.

Characterizing post-drainage succession in Thermokarst Lake Basins on the Seward Peninsula, Alaska with TerraSAR-X Backscatter and Landsat-based NDVI data

USGS Publications Warehouse

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

2012-01-01

Drained thermokarst lake basins accumulate significant amounts of soil organic carbon in the form of peat, which is of interest to understanding carbon cycling and climate change feedbacks associated with thermokarst in the Arctic. Remote sensing is a tool useful for understanding temporal and spatial dynamics of drained basins. In this study, we tested the application of high-resolution X-band Synthetic Aperture Radar (SAR) data of the German TerraSAR-X satellite from the 2009 growing season (July–September) for characterizing drained thermokarst lake basins of various age in the ice-rich permafrost region of the northern Seward Peninsula, Alaska. To enhance interpretation of patterns identified in X-band SAR for these basins, we also analyzed the Normalized Difference Vegetation Index (NDVI) calculated from a Landsat-5 Thematic Mapper image acquired on July 2009 and compared both X-band SAR and NDVI data with observations of basin age. We found significant logarithmic relationships between (a) TerraSAR-X backscatter and basin age from 0 to 10,000 years, (b) Landat-5 TM NDVI and basin age from 0 to 10,000 years, and (c) TerraSAR-X backscatter and basin age from 50 to 10,000 years. NDVI was a better indicator of basin age over a period of 0–10,000 years. However, TerraSAR-X data performed much better for discriminating radiocarbon-dated basins (50–10,000 years old). No clear relationships were found for either backscatter or NDVI and basin age from 0 to 50 years. We attribute the decreasing trend of backscatter and NDVI with increasing basin age to post-drainage changes in the basin surface. Such changes include succession in vegetation, soils, hydrology, and renewed permafrost aggradation, ground ice accumulation and localized frost heave. Results of this study show the potential application of X-band SAR data in combination with NDVI data to map long-term succession dynamics of drained thermokarst lake basins.

Seismicity on the western Greenland Ice Sheet: Surface fracture in the vicinity of active moulins

DOE PAGES

Carmichael, Joshua D.; Joughin, Ian; Behn, Mark D.; ...

2015-06-25

We analyzed geophone and GPS measurements collected within the ablation zone of the western Greenland Ice Sheet during a ~35 day period of the 2011 melt season to study changes in ice deformation before, during, and after a supraglacial lake drainage event. During rapid lake drainage, ice flow speeds increased to ~400% of winter values, and icequake activity peaked. At times >7 days after drainage, this seismicity developed variability over both diurnal and longer periods (~10 days), while coincident ice speeds fell to ~150% of winter values and showed nightly peaks in spatial variability. Approximately 95% of all detected seismicitymore » in the lake basin and its immediate vicinity was triggered by fracture propagation within near-surface ice (<330 m deep) that generated Rayleigh waves. Icequakes occurring before and during drainage frequently were collocated with the down flow (west) end of the primary hydrofracture through which the lake drained but shifted farther west and outside the lake basin after the drainage. We interpret these results to reveal vertical hydrofracture opening and local uplift during the drainage, followed by enhanced seismicity and ice flow on the downstream side of the lake basin. This region collocates with interferometric synthetic aperture radar-measured speedup in previous years and could reflect the migration path of the meltwater supplied to the bed by the lake. The diurnal seismic signal can be associated with nightly reductions in surface melt input that increase effective basal pressure and traction, thereby promoting elevated strain in the surficial ice.« less

Environmental controls on drainage behavior of an ephemeral stream

USGS Publications Warehouse

Blasch, K.W.; Ferré, T.P.A.; Vrugt, J.A.

2010-01-01

Streambed drainage was measured at the cessation of 26 ephemeral streamflow events in Rillito Creek, Tucson, Arizona from August 2000 to June 2002 using buried time domain reflectometry (TDR) probes. An unusual drainage response was identified, which was characterized by sharp drainage from saturation to near field capacity at each depth with an increased delay between depths. We simulated the drainage response using a variably saturated numerical flow model representing a two-layer system with a high permeability layer overlying a lower permeability layer. Both the observed data and the numerical simulation show a strong correlation between the drainage velocity and the temperature of the stream water. A linear combination of temperature and the no-flow period preceding flow explained about 90% of the measured variations in drainage velocity. Evaluation of this correlative relationship with the one-dimensional numerical flow model showed that the observed temperature fluctuations could not reproduce the magnitude of variation in the observed drainage velocity. Instead, the model results indicated that flow duration exerts the most control on drainage velocity, with the drainage velocity decreasing nonlinearly with increasing flow duration. These findings suggest flow duration is a primary control of water availability for plant uptake in near surface sediments of an ephemeral stream, an important finding for estimating the ecological risk of natural or engineered changes to streamflow patterns. Correlative analyses of soil moisture data, although easy and widely used, can result in erroneous conclusions of hydrologic cause—effect relationships, and demonstrating the need for joint physically-based numerical modeling and data synthesis for hypothesis testing to support quantitative risk analysis.

Trematode fauna of prosobranch snails of the genus Semisulcospira in Lake Biwa and the connected drainage system.

PubMed

Urabe, Misako

2003-03-01

The parasite fauna of prosobranch snails of the genus Semisulcospira was surveyed in Lake Biwa and the adjacent water system. One aspidogastrean and 28 digenetic trematode taxa were detected in 19209 snails consisting of 10 morphological species. There was no trematode species peculiar to members of the subgenus Biwamelania that is endemic to the Lake Biwa water system. However, one species, Notocotylus magniovatus, was found only in the non-endemic subgenus Semisulcospira. Of 23 digenean taxa detected in more than one host, 13 were distributed in both the lake and the tributaries. Seven of these had host taxa, more than 1% of which were infected with the parasite in both the lake and the tributaries, four had such hosts only in the tributaries, and two had no such hosts. Three species detected only in Lake Biwa were previously reported from other rivers in Japan. In the seven species detected only in the tributaries, two species had life cycles that could be maintained only in rivers. These results indicate that the core areas for the distribution of parasites of Semisulcospira are tributaries, and the lake is a sink for these species. These results contradict the expectation that the parasite fauna should be richer in the lake than in tributaries because the lake is a stable habitat over a geological time scale and has more divergent freshwater animals than the adjacent water system. Copyright 2002 Elsevier Science Ireland Ltd.

Benthic foraminiferal assemblages as bio-indicators of metals contamination in sediments, Qarun Lake as a case study, Egypt

NASA Astrophysics Data System (ADS)

Abd El Naby, Ahmed; Al Menoufy, Safia; Gad, Ahmed

2018-03-01

Qarun Lake, in the Fayoum Depression of the Western Desert of Egypt, lies within the deepest area in the River Nile flood plain. The drainage water in the Qarun Lake is derived from the discharge of the natural and artificial drainage systems in the Fayoum. Mixed domestic and agricultural pollutants, including heavy metals, nitrates, phosphates, sulfates and pesticides, are discharged into Qarun Lake. Forty-six samples, collected from the undisturbed layer of sediments were used for benthic foraminiferal analysis. Concentrations of some selected trace metal elements (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V, and Zn) were also determined. Statistical analysis of the abiotic variables (Texture distribution of sediments, Physico-chemical parameters, and metals concentrations) and of the biotic variables (distribution of benthic foraminiferal species) were also performed. The Q-mode cluster analysis of benthic foraminiferal distribution has provided evidence that the Qarun Lake can be subdivided into two cluster groups (A and B), reflecting environmental changes in the lake ecosystem. Cluster B can also be subdivided into two sub-clusters (B1 and B2). The presence of only pollution tolerant taxa with higher faunal density and lower diversity and the absence of the other foraminiferal assemblages in cluster A were attributed to the high concentration of trace metal elements and the strong environmental stress at the eastern and central parts of the Qarun Lake.

Lakes as organic matter upgraders - seasonal variation in biochemical compositions of in- and outflowing particles in pre-alpine Lake Lunz, Austria

NASA Astrophysics Data System (ADS)

Khan, Samiullah; Hollaus, Lisa-Maria; Schelker, Jakob; Ejarque, Elisabet; Battin, Tom; Kainz, Martin

2016-04-01

Lakes are typically recharged by inflowing stream water and discharge into outflowing streams. In this multiannual field study on pre-alpine, oligotrophic Lake Lunz, Lower Austria, we hypothesized that, irrespective of seasons, stream water recharging the lake contains predominantly recalcitrant particular organic matter (POM; >1.2 um particle size), whereas outflowing lake water is mostly composed of more labile, algae-derived POM. We collected POM for 3 years (2013-2015) at a monthly basis from the inflowing and outflowing streams of Lake Lunz, analyzed POM content, its carbon and nitrogen, their stable isotopes, and fatty acids as biochemical indicators of POM sources. Preliminary results show that, independent of seasons, inflowing POM is rich in terrestrial markers, as evidenced by long-chain saturated fatty acids (>C22:0), with little contribution of autochthonous stream POM, such as algae-derived long-chain polyunsaturated fatty acids (LC-PUFA). However, POM in outflowing water contained considerably less terrestrial markers, but clearly higher contents of highly nutritious, algae-derived LC-PUFA. These results suggest that oligotrophic Lake Lunz acts as a biochemical upgrader within the fluvial network of this drainage basin and supplies highly nutritional POM to consumers further downstream. Ongoing research is aimed at identifying how much of the terrestrial and autochthonous POM is retained and processed in the lake (biota, sediments, or respired).

Abrupt drainage cycles of the Fennoscandian Ice Sheet

PubMed Central

Soulet, Guillaume; Ménot, Guillemette; Bayon, Germain; Rostek, Frauke; Ponzevera, Emmanuel; Toucanne, Samuel; Lericolais, Gilles; Bard, Edouard

2013-01-01

Continental ice sheets are a key component of the Earth’s climate system, but their internal dynamics need to be further studied. Since the last deglaciation, the northern Eurasian Fennoscandian Ice Sheet (FIS) has been connected to the Black Sea (BS) watershed, making this basin a suitable location to investigate former ice-sheet dynamics. Here, from a core retrieved in the BS, we combine the use of neodymium isotopes, high-resolution elemental analysis, and biomarkers to trace changes in sediment provenance and river runoff. We reveal cyclic releases of meltwater originating from Lake Disna, a proglacial lake linked to the FIS during Heinrich Stadial 1. Regional interactions within the climate–lake–FIS system, linked to changes in the availability of subglacial water, led to abrupt drainage cycles of the FIS into the BS watershed. This phenomenon raised the BS water level by ∼100 m until the sill of the Bosphorus Strait was reached, flooding the vast northwestern BS shelf and deeply affecting the hydrology and circulation of the BS and, probably, of the Marmara and Aegean Seas. PMID:23569264

Comparative analysis of discharges into Lake Michigan, Phase I - Southern Lake Michigan.

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

Veil, J. A.; Elcock, D.; Gasper, J. R.

2008-06-30

BP Products North America Inc. (BP) owns and operates a petroleum refinery located on approximately 1,700 acres in Whiting, East Chicago, and Hammond, Indiana, near the southern tip of Lake Michigan. BP provided funding to Purdue University-Calumet Water Institute (Purdue) and Argonne National Laboratory (Argonne) to conduct studies related to wastewater treatment and discharges. Purdue and Argonne are working jointly to identify and characterize technologies that BP could use to meet the previous discharge permit limits for total suspended solids (TSS) and ammonia after refinery modernization. In addition to the technology characterization work, Argonne conducted a separate project task, whichmore » is the subject of this report. In Phase I of a two-part study, Argonne estimated the current levels of discharge to southern Lake Michigan from significant point and nonpoint sources in Illinois, Indiana, and portions of Michigan. The study does not consider all of the chemicals that are discharged. Rather, it is narrowly focused on a selected group of pollutants, referred to as the 'target pollutants'. These include: TSS, ammonia, total and hexavalent chromium, mercury, vanadium, and selenium. In Phase II of the study, Argonne will expand the analysis to cover the entire Lake Michigan drainage basin.« less

Groundwater and surface water interaction in flow-through gravel pit lakes.

NASA Astrophysics Data System (ADS)

Nella Mollema, Pauline; Antonellini, Marco

2015-04-01

Gravel pits are excavated in aquifers to fulfill the need for construction materials. Flow-through lakes form when the gravel pits are below the water table and fill with groundwater. In certain areas there are more than 60 of these lakes close together and their presence changes the drainage patterns and water- and hydrochemical budgets of a watershed. In flow-through gravel pit lakes, groundwater mixes with surface water and interacts with the atmosphere; outflow occurs only via groundwater. The lifespan of gravel pit lakes may be up to thousands of years as their depth to surface ratio is typically large and sedimentation rates are low. We have studied two gravel pit lake systems, a fluvial freshwater system in the Netherlands and a coastal brackish lake system in Italy. One Dutch gravel pit lake studied in detail is in part artificially replenished with Meuse River water for drinking water production that occurs downstream of the lake by water pumps. The Italian gravel pit lakes are fed by brackish groundwater that is a mix of freshwater from precipitation, Apennine Rivers and brackish (Holocene) Adriatic Sea water. Here, the drainage system of the low lying land enhances groundwater flow into the lake. Surface water evaporation is larger in temperate and Mediterranean climates than the actual evapotranspiration of pre-existing grassland and forests. The lakes, therefore, cause a loss of freshwater. The creation of water surfaces allows algae and other flora and fauna to develop. In general, water becomes gradually enriched in certain chemical constituents on its way through the hydrological cycle, especially as groundwater due to water-rock interactions. When groundwater ex-filtrates into gravel pit lakes, the natural flow of solutes towards the sea is interrupted. Hydrochemical analysis of ground- and surface waters, as well as chemical analysis of lake bottom sediments and stable H and O isotope data, show that gravel pit lake water is characterized (among

Relative importance of impervious area, drainage density, width function, and subsurface storm drainage on flood runoff from an urbanized catchment

NASA Astrophysics Data System (ADS)

Ogden, Fred L.; Raj Pradhan, Nawa; Downer, Charles W.; Zahner, Jon A.

2011-12-01

The literature contains contradictory conclusions regarding the relative effects of urbanization on peak flood flows due to increases in impervious area, drainage density and width function, and the addition of subsurface storm drains. We used data from an urbanized catchment, the 14.3 km2 Dead Run watershed near Baltimore, Maryland, USA, and the physics-based gridded surface/subsurface hydrologic analysis (GSSHA) model to examine the relative effect of each of these factors on flood peaks, runoff volumes, and runoff production efficiencies. GSSHA was used because the model explicitly includes the spatial variability of land-surface and hydrodynamic parameters, including subsurface storm drains. Results indicate that increases in drainage density, particularly increases in density from low values, produce significant increases in the flood peaks. For a fixed land-use and rainfall input, the flood magnitude approaches an upper limit regardless of the increase in the channel drainage density. Changes in imperviousness can have a significant effect on flood peaks for both moderately extreme and extreme storms. For an extreme rainfall event with a recurrence interval in excess of 100 years, imperviousness is relatively unimportant in terms of runoff efficiency and volume, but can affect the peak flow depending on rainfall rate. Changes to the width function affect flood peaks much more than runoff efficiency, primarily in the case of lower density drainage networks with less impermeable area. Storm drains increase flood peaks, but are overwhelmed during extreme rainfall events when they have a negligible effect. Runoff in urbanized watersheds with considerable impervious area shows a marked sensitivity to rainfall rate. This sensitivity explains some of the contradictory findings in the literature.

Endoscopic ultrasound-guided transluminal drainage for peripancreatic fluid collections: where are we now?

PubMed

Kawakami, Hiroshi; Itoi, Takao; Sakamoto, Naoya

2014-07-01

Endoscopic drainage for pancreatic and peripancreatic fluid collections (PFCs) has been increasingly used as a minimally invasive alternative to surgical or percutaneous drainage. Recently, endoscopic ultrasound-guided transluminal drainage (EUS-TD) has become the standard of care and a safe procedure for nonsurgical PFC treatment. EUS-TD ensures a safe puncture, avoiding intervening blood vessels. Single or multiple plastic stents (combined with a nasocystic catheter) were used for the treatment of PFCs for EUS-TD. More recently, the use of covered self-expandable metallic stents (CSEMSs) has provided a safer and more efficient approach route for internal drainage. We focused our review on the best approach and stent to use in endoscopic drainage for PFCs. We reviewed studies of EUS-TD for PFCs based on the original Atlanta Classification, including case reports, case series, and previous review articles. Data on clinical outcomes and adverse events were collected retrospectively. A total of 93 patients underwent EUS-TD of pancreatic pseudocysts using CSEMSs. The treatment success and adverse event rates were 94.6% and 21.1%, respectively. The majority of complications were of mild severity and resolved with conservative therapy. A total of 56 patients underwent EUS-TD using CSEMSs for pancreatic abscesses or infected walled-off necroses. The treatment success and adverse event rates were 87.8% and 9.5%, respectively. EUS-TD can be performed safely and efficiently for PFC treatment. Larger diameter CSEMSs without additional fistula tract dilation for the passage of a standard scope are needed to access and drain for PFCs with solid debris.

Home destruction examination: Grass Valley Fire, Lake Arrowhead, California

Treesearch

Jack D. Cohen; Richard D. Stratton

2008-01-01

The Grass Valley Fire started October 22, 2007 at approximately 0508, one-mile west of Lake Arrowhead in the San Bernardino Mountains. Fuel and weather conditions were extreme due to drought, dry Santa Ana winds, and chaparral and conifer vegetation on steep terrain. The fire proceeded south through the Grass Valley drainage one-mile before impacting an area of dense...

Hydrology and water quality of lakes and streams in Orange County, Florida

USGS Publications Warehouse

German, Edward R.; Adamski, James C.

2005-01-01

Orange County, Florida, is continuing to experience a large growth in population. In 1920, the population of Orange County was less than 20,000; in 2000, the population was about 896,000. The amount of urban area around Orlando has increased considerably, especially in the northwest part of the County. The eastern one-third of the County, however, had relatively little increase in urbanization from 1977-97. The increase of population, tourism, and industry in Orange County and nearby areas changed land use; land that was once agricultural has become urban, industrial, and major recreation areas. These changes could impact surface-water resources that are important for wildlife habitat, for esthetic reasons, and potentially for public supply. Streamflow characteristics and water quality could be affected in various ways. As a result of changing land use, changes in the hydrology and water quality of Orange County's lakes and streams could occur. Median runoff in 10 selected Orange County streams ranges from about 20 inches per year (in/yr) in the Wekiva River to about 1.1 in/yr in Cypress Creek. The runoff for the Wekiva River is significantly higher than other river basins because of the relatively constant spring discharge that sustains streamflow, even during drought conditions. The low runoff for the Cypress Creek basin results from a lack of sustained inflow from ground water and a relatively large area of lakes within the drainage basin. Streamflow characteristics for 13 stations were computed on an annual basis and examined for temporal trends. Results of the trend testing indicate changes in annual mean streamflow, 1-day high streamflow, or 7-day low streamflow at 8 of the 13 stations. However, changes in 7-day low streamflow are more common than changes in annual mean or 1-day high streamflow. There is probably no single reason for the changes in 7-day low streamflows, and for most streams, it is difficult to determine definite reasons for the flow

Regional patterns and local variability of dry and occult deposition strongly influence sulfate concentrations in Maine lakes

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

Norton, S.A.; Kahl, J.S.; Brakke, D.F.

1988-01-01

There is great uncertainty and large cost in making dry deposition measurements. The authors present evidence based on wet deposition, evapotranspiration, S storage in lake sediments, and sulfate concentrations in lakes and streams in Maine that the dry deposition flux of sulfur to drainage basins of lakes in Maine ranges from nearly 0% to more than 100% of wet deposition, even in small areas. The regional pattern of sulfate concentrations in Maine lakes is due to gradients in both wet and dry deposition and variation in evapotranspiration. Patterns are modified locally by lakes hydrologic type, elevation, vegetation, and terrestrial drainagemore » basin aspect. (Copyright (c) 1988 Elsevier Science Publishers B.V.)« less

Modern lacustrine stromatolites, Walker Lake, Nevada

NASA Astrophysics Data System (ADS)

Osborne, Robert H.; Licari, Gerald R.; Link, Martin H.

1982-05-01

The Walker River drainage basin occupies about 10,000 km 2 in western Nevada and parts of California and is essentially a closed hydrologic system which drains from the crest of the Sierra Nevada in California and terminates in Walker Lake, Nevada. Walker Lake trends north and is about 27.4 km long and 8 km wide with water depths exceeding 30.5 m. The lake is situated in an asymmetric basin with steep alluvial fans flanking the western shoreline (Wassuk Range) and more gentle but areally more extensive alluvial fans flanking the eastern shoreline (Gillis Range). Exposed lake terraces and the present shoreline of Walker Lake record a sequence of Pleistocene and Holocene stromatolitic and tufaceous carbonate deposits. Small generalized and columnar stromatolites, frequently encrusted on exposed coarse-grained clasts or bedrock, are present along parts of the nearshore margin of Walker Lake and at elevated lake stands. Columnar stromatolites as much as 4 cm high are subcylindrical to club shaped discrete, and laterally linked at the base with local branching. These digitate stromatolites start as wavy, generalized stromatolites which are vertically transitional to small, laterally linked cabbage heads with laminae which thicken over the crests. Although algal structures are not well preserved in the older stromatolites, recent precipitation of low magnesium calcite occurs as smooth encrustations and as tiny mounds which are consistently associated with a diverse, seasonally variable, green and blue-green algal community including Cladophora glomerata, Ulothrix (cf. aequalis), Gongrosira, Schizothrix, Amphithrix janthina, Calothrix, Homeothrix, Spirulina, Anabaena, Lyngbya, and Entophysalis. Cladophora glomerata and a species of Ulothrix, which are the two most abundant algae within the Walker Lake stromatolite community, are known to condition semi-alkaline lake water by the removal of CO 2 from bicarbonate during photosynthesis. Such conditioning results in the

Multidisciplinary distinction of mass-movement and flood-induced deposits in lacustrine environments: implications for Holocene palaeohydrology and natural hazards (Lake Ledro, Southern Alps, Italy)

NASA Astrophysics Data System (ADS)

Simonneau, A.; Chapron, E.; Vannière, B.; Wirth, S. B.; Gilli, A.; Di Giovanni, C.; Anselmetti, F. S.; Desmet, M.; Magny, M.

2012-08-01

from the combination of heavy rainfall and snowmelt. The recurrence of flash-flood events during the Holocene was however not high enough to affect pedogenesis processes and highlight several wet regional periods during the Holocene. The Holocene period is divided into four phases of environmental evolution. Over the first half of the Holocene, a progressive stabilization of the soils present through the catchment of Lake Ledro was associated with a progressive reforestation of the area and only interrupted during the wetter 8.2 event when the soil destabilization was particularly important. Lower soil erosion was recorded during the Mid-Holocene climatic optimum (8000-4200 cal. yr BP) and associated with higher algal production. Between 4200 and 3100 cal. yr BP, both wetter climate and human activities within the drainage basin drastically increased soil erosion rates. Finally, from 3100 cal. yr BP to the present-day, results suggest increasing and changing human land-use.

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

A combined CaO/electrochemical treatment of the acid mine drainage from the "Robule" Lake.

PubMed

Orescanin, Visnja; Kollar, Robert

2012-01-01

The purpose of this work was development and application of the purification system suitable for the treatment of the acid mine drainage (AMD) accumulated in the "Robule" Lake, which represents the part of the Bor copper mining and smelting complex, Serbia. The study was undertaken in order to minimize adverse effect on the environment caused by the discharge of untreated AMD, which was characterized with low pH value (2.63) and high concentration of heavy metals (up to 610 mg/L) and sulfates (up to 12,000 mg/L). The treatment of the effluent included pretreatment/pH adjustment with CaO followed by electrocoagulation using iron and aluminum electrode sets. Following the final treatment, the decrease in the concentration of heavy metals ranged from 40 up to 61000 times depending on the metal and its initial concentration. The parameters, color and turbidity were removed completely in the pretreatment step, while the removal efficiencies for other considered parameters were as follows: EC = 55.48%, SO(4) (2-) = 70.83%, Hg = 98.36%, Pb = 97.50%, V = 98.43%, Cr = 99.86%, Mn = 97.96%, Fe = 100.00%, Co = 99.96%, Ni = 99.78%, Cu = 99.99% and Zn = 99.94%. Because the concentrations of heavy metals in the electrochemically treated AMD (ranging from 0.001 to 0.336 mg/L) are very low, the negative impact of this effluent on the aquatic life and humans is not expected. The sludge generated during the treatment of AMD is suitable for reuse for at least two purposes (pretreatment of AMD and covering of the flotation waste heap). From the presented results, it could be concluded that electrochemical treatment is a suitable approach for the treatment of AMD.

Management Practices Used in Agricultural Drainage Ditches to Reduce Gulf of Mexico Hypoxia.

PubMed

Faust, Derek R; Kröger, Robert; Moore, Matthew T; Rush, Scott A

2018-01-01

Agricultural non-point sources of nutrients and sediments have caused eutrophication and other water quality issues in aquatic and marine ecosystems, such as the annual occurrence of hypoxia in the Gulf of Mexico. Management practices have been implemented adjacent to and in agricultural drainage ditches to promote their wetland characteristics and functions, including reduction of nitrogen, phosphorus, and sediment losses downstream. This review: (1) summarized studies examining changes in nutrient and total suspended solid concentrations and loads associated with management practices in drainage ditches (i.e., riser and slotted pipes, two-stage ditches, vegetated ditches, low-grade weirs, and organic carbon amendments) with emphasis on the Lower Mississippi Alluvial Valley, (2) quantified management system effects on nutrient and total suspended solid concentrations and loads and, (3) identified information gaps regarding water quality associated with these management practices and research needs in this area. In general, management practices used in drainage ditches at times reduced losses of total suspended solids, N, and P. However, management practices were often ineffective during storm events that were uncommon and intense in duration and volume, although these types of events could increase in frequency and intensity with climate change. Studies on combined effects of management practices on drainage ditch water quality, along with research towards improved nutrient and sediment reduction efficiency during intense storm events are urgently needed.

Bundle of measures for external cerebral ventricular drainage-associated ventriculitis.

PubMed

Chatzi, Maria; Karvouniaris, Marios; Makris, Demosthenes; Tsimitrea, Eleni; Gatos, Charalampos; Tasiou, Anastasia; Mantzarlis, Kostas; Fountas, Kostas N; Zakynthinos, Epaminondas

2014-01-01

To assess the prevalence and outcome of external cerebral ventricular drainage-associated ventriculitis in neurocritical patients before and after the implementation of a bundle of external cerebral ventricular drainage-associated ventriculitis control measures. Clinical prospective case series. University Hospital of Larissa, Greece. Consecutive patients were recruited from the ICU of the hospital. Patient inclusion criteria included presence of external ventricular drainage and ICU stay more than 48 hours. The bundle of external cerebral ventricular drainage-associated ventriculitis control measures included 1) reeducation of ICU personnel on issues of infection control related to external cerebral ventricular drainage, 2) meticulous intraventricular catheter handling, 3) cerebrospinal fluid sampling only when clinically necessary, and 4) routine replacement of the drainage catheter on the seventh drainage day if the catheter was still necessary. The bundle was applied after an initial period (preintervention) where standard policy for external cerebral ventricular drainage-associated ventriculitis was established. External cerebral ventricular drainage-associated ventriculitis prevalence, external cerebral ventricular drainage-associated ventriculitis events per 1,000 drainage days (drain-associated infection rate), length of ICU stay, Glasgow Outcome Scale at 6 months, and risk factors for external cerebral ventricular drainage-associated ventriculitis. Eighty-two patients entered the study in the preintervention period and 57 patients during the intervention period. During the preintervention and intervention period, external cerebral ventricular drainage-associated ventriculitis prevalence was 28% and 10.5% (p = 0.02) and drain-associated infection rate was 18 and 7.1, respectively (p = 0.0001); mean (95% CI) length of ICU stay in patients who presented external cerebral ventricular drainage-associated ventriculitis was 44.4 days (36.4-52.4 d), whereas mean

Meetings and Events about Western Lake Erie Basin

EPA Pesticide Factsheets

Western Lake Erie Basin, near Toledo (Ohio), 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

Estimation of sediment inflows to Lake Tuscaloosa, Alabama, 2009-11

USGS Publications Warehouse

Lee, K.G.

2013-01-01

The U.S. Geological Survey, in cooperation with the City of Tuscaloosa, evaluated the concentrations, loads, and yields of suspended sediment in the tributaries to Lake Tuscaloosa in west-central Alabama, from October 1, 2008, to January 31, 2012. The collection and analysis of these data will facilitate the comparison with historical data, serve as a baseline for future sediment-collection efforts, and help to identify areas of concern. Lake Tuscaloosa, at the reservoir dam, receives runoff from a drainage area of 423 square miles (mi2). Basinwide in 2006, forested land was the primary land cover (68 percent). Comparison of historical imagery with the National Land Cover Database (2001 and 2006) indicated that the greatest temporal land-use change was timber harvest. The land cover in 2006 was indicative of this change, with shrub/scrub land (12 percent) being the secondary land use in the basin. Agricultural land use (10 percent) was represented predominantly by hay and pasture or grasslands. Urban land use was minimal, accounting for 4 percent of the entire basin. The remaining 6 percent of the basin has a land use of open water or wetlands. Storm and monthly suspended-sediment samples were collected from seven tributaries to Lake Tuscaloosa: North River, Turkey Creek, Binion Creek, Pole Bridge Creek, Tierce Creek, Carroll Creek, and Brush Creek. Suspended-sediment concentrations and streamflow measurements were statistically analyzed to estimate annual suspended-sediment loads and yields from each of these contributing watersheds. Estimated annual suspended-sediment yields in 2009 were 360, 540, and 840 tons per square mile (tons/mi2) at the North River, Turkey Creek, and Carroll Creek streamflow-gaging stations, respectively. Estimated annual suspended-sediment yields in 2010 were 120 and 86 tons/mi2 at the Binion Creek and Pole Bridge Creek streamflow-gaging stations, respectively. Estimated annual suspended-sediment yields in 2011 were 190 and 300 tons/mi2

Fishes of the Blackwater River Drainage, Tucker County, West Virginia

USGS Publications Warehouse

Cincotta, Daniel A.; Welsh, Stuart A.; Wegman, Douglas P.; Oldham, Thomas E.; Hedrick, Lara B.

2015-01-01

The Blackwater River, a tributary of the upper Cheat River of the Monongahela River, hosts a modest fish fauna. This relatively low diversity of fish species is partly explained by its drainage history. The Blackwater was once part of the prehistoric, northeasterly flowing St. Lawrence River. During the Pleistocene Epoch, the fauna was significantly affected by glacial advance and by proglacial lakes and their associated overflows. After the last glacial retreat, overflow channels, deposits, and scouring altered drainage courses and connected some of the tributaries of the ancient Teays and Pittsburgh drainages. These major alterations allowed the invasion of fishes from North America's more species-rich southern waters. Here we review fish distributions based on 67 surveys at 34 sites within the Blackwater River drainage, and discuss the origin and status of 37 species. Within the Blackwater River watershed, 30 species (20 native, 10 introduced) have been reported from upstream of Blackwater Falls, whereas 29 (26 native, 3 introduced) have been documented below the Falls. Acid mine drainage, historic lumbering, and human encroachment have impacted the Blackwater's ichthyofauna. The fishes that have been most affected are Salvelinus fontinalis (Brook Trout), Clinostomus elongatus (Redside Dace), Nocomis micropogon (River Chub), Hypentelium nigricans (Northern Hog Sucker), Etheostoma flabellare (Fantail Darter), and Percina maculata(Blackside Darter). The first two species incurred range reductions, whereas the latter four were probably extirpated. In the 1990s, acid remediation dramatically improved the water quality of the river below Davis. Recent surveys in the lower drainage revealed 15 fishes where none had been observed since at least the 1940s; seven of these (Cyprinella spiloptera [Spotfin Shiner], Luxilus chrysocephalus [Striped Shiner], Notropis photogenis [Silver Shiner], N. rubellus [Rosyface Shiner];Micropterus dolomieu

Ratosa playa lake in southern Spain. Karst pan or compound sink?

PubMed

Rodríguez-Rodríguez, Miguel; Martos-Rosillo, Sergio; Pedrera, Antonio; Benavente-Herrera, José

2015-04-01

In Andalusia (Spain), there are more than 45 semiarid playa lakes protected as natural reserves and related to karstic outcrops. Some of them are located over regional karstic aquifers and have internal drainage networks with sporadic surface outlets, such as sinkholes (compound sinks), but the majority of such playas have no internal drainage systems, so the only water output is evaporation (karst pans). Karst pans are perched and disconnected from the groundwater system. The fact that the Ratosa playa lake is partially located over a karstic Sierra, as well as other hydromorphological observations, it is suggested that the system could be of a compound type, but a detailed hydrogeological analysis showed that the playa is disconnected from the aquifer, so it is in fact a karst pan. Once the hydrological functioning had been established, a monthly water balance for a 10-year period (1998-2008), enabled us to reproduce the evolution of the water level of the playa lake. Estimations of runoff were carried out by a soil water estimate for a water holding capacity in the soil of 191 mm. Results show a good correlation (>90%) after calibration with the time series of water level in the lake for the same period confirming geological observations. Our results highlight that this water body is extremely vulnerable to hydrological alterations of its watershed caused by human activities, particularly those related to land-use change for agriculture. For this reason, we propose a new protection zone, based on hydrological knowledge, instead of the present Peripheral Area of Protection.

Comparison between autologous blood transfusion drainage and closed-suction drainage/no drainage in total knee arthroplasty: a meta-analysis.

PubMed

Hong, Kun-Hao; Pan, Jian-Ke; Yang, Wei-Yi; Luo, Ming-Hui; Xu, Shu-Chai; Liu, Jun

2016-08-01

Autologous blood transfusion (ABT) drainage system is a new unwashed salvaged blood retransfusion system for total knee replacement (TKA). However, whether to use ABT drainage, closed-suction (CS) drainage or no drainage in TKA surgery remains controversial. This is the first meta-analysis to assess the clinical efficiency, safety and potential advantages regarding the use of ABT drains compared with closed-suction/no drainage. PubMed, Embase, and the Cochrane Library were comprehensively searched in March 2015. Fifteen randomized controlled trials (RCTs) were identified and pooled for statistical analysis. The primary outcome evaluated was homologous blood transfusion rate. The secondary outcomes were post-operative haemoglobin on days 3-5, length of hospital stay and wound infections after TKA surgery. The pooled data included 1,721 patients and showed that patients in the ABT drainage group might benefit from lower blood transfusion rates (16.59 % and 37.47 %, OR: 0.28 [0.14, 0.55]; 13.05 % and 16.91 %, OR: 0.73 [0.47,1.13], respectively). Autologous blood transfusion drainage and closed-suction drainage/no drainage have similar clinical efficacy and safety with regard to post-operative haemoglobin on days 3-5, length of hospital stay and wound infections. Autologous blood transfusion drainage offers a safe and efficient alternative to CS/no drainage with a lower blood transfusion rate. Future large-volume high-quality RCTs with extensive follow-up will affirm and update this system review.

Pre-operative biliary drainage for obstructive jaundice

PubMed Central

Fang, Yuan; Gurusamy, Kurinchi Selvan; Wang, Qin; Davidson, Brian R; Lin, He; Xie, Xiaodong; Wang, Chaohua

2014-01-01

% and 100%. There was no significant difference in mortality (40/265, weighted proportion 14.9%) in the pre-operative biliary drainage group versus the direct surgery group (34/255, 13.3%) (RR 1.12; 95% CI 0.73 to 1.71; P = 0.60). The overall serious morbidity was higher in the pre-operative biliary drainage group (60 per 100 patients in the pre-operative biliary drainage group versus 26 per 100 patients in the direct surgery group) (RaR 1.66; 95% CI 1.28 to 2.16; P = 0.0002). The proportion of patients who developed serious morbidity was significantly higher in the pre-operative biliary drainage group (75/102, 73.5%) in the pre-operative biliary drainage group versus the direct surgery group (37/94, 37.4%) (P < 0.001). Quality of life was not reported in any of the trials. There was no significant difference in the length of hospital stay (2 trials, 271 patients; MD 4.87 days; 95% CI −1.28 to 11.02; P = 0.12) between the two groups. Trial sequential analysis showed that for mortality only a small proportion of the required information size had been obtained. There seemed to be no significant differences in the subgroup of trials assessing percutaneous compared to endoscopic drainage. Authors’ conclusions There is currently not sufficient evidence to support or refute routine pre-operative biliary drainage for patients with obstructive jaundice. Pre-operative biliary drainage may increase the rate of serious adverse events. So, the safety of routine pre-operative biliary drainage has not been established. Pre-operative biliary drainage should not be used in patients undergoing surgery for obstructive jaundice outside randomised clinical trials. PMID:22972086

Boundary Layer Temporal Evolution Observed by Doppler LiDAR Upwind of a Lake-Effect Snow Event

NASA Astrophysics Data System (ADS)

King, D.; Kristovich, D.

2017-12-01

Lake-effect snow (LES) annually affects the Great Lakes region. It can impact communities economically, recreationally and perhaps result in fatalities. Previous studies have shown that the upwind shore of a LES system tends to be a region for mesoscale downdrafts. This study intends to show how the depth of the boundary (BL) on the upwind shore and how it could influence a LES event downstream. From December 7-10, 2016, we deployed a Halo-Photonics Streamline pulsed Doppler LiDAR at Illinois Beach State Park in Zion, Illinois, to observe the evolving BL wind structure and depth upwind of the growing LES over eastern Lake Michigan. The LiDAR scans included vertical stare, velocity-azimuth display (VAD), and range height indicator (RHI) modes to display the BL depth as well as LES cloud band structure. The BL depth was observed by turbulent velocities and backscatter profiles from the LiDAR. The BL was found to be approximately one kilometer during the day, and reduced to near surface at night. The BL depth, overall, increased from the 8th to the 9th, while snowfall rate decreased on the downwind shore. This suggests that local BL dynamics have less influence on downwind convection and snow production than originally anticipated. The larger scale environment appears to play a larger role in the multi-day BL evolution.

Movement of road salt to a small New Hampshire lake

USGS Publications Warehouse

Rosenberry, D.O.; Bukaveckas, P.A.; Buso, D.C.; Likens, G.E.; Shapiro, A.M.; Winter, T.C.

1999-01-01

Runoff of road salt from an interstate highway in New Hampshire has led to contamination of a lake and a stream that flows into the lake, in spite of the construction of a diversion berm to divert road salt runoff out of the lake drainage basin. Chloride concentration in the stream has increased by over an order of magnitude during the 23 yr since the highway was opened, and chloride concentration in the lake has tripled. Road salt moves to the lake primarily via the contaminated stream, which provides 53% of all the chloride to the lake and only 3% of the total streamflow to the lake. The stream receives discharge of salty water froth leakage through the diversion berm. Uncontaminated ground water dilutes the stream downstream of the berm. However, reversals of gradient during summer months, likely caused by transpiration from deciduous trees, result in flow of contaminated stream water into the adjacent ground water along the lowest 40-m reach of the stream. This contaminated ground water then discharges into the lake along a 70-m-wide segment of lake shore. Road salt is pervasive in the bedrock between the highway and the lake, but was not detected at all of the wells in the glacial overburden. Of the 500 m of shoreline that could receive discharge of saly ground water directly from the highway, only a 50-m-long segment appears to be contaminated.

A mass balance mercury budget for a mine-dominated lake: Clear Lake, California

USGS Publications Warehouse

Suchanek, T.H.; Cooke, J.; Keller, K.; Jorgensen, S.; Richerson, P.J.; Eagles-Smith, Collin A.; Harner, E.J.; Adam, D.P.

2009-01-01

The Sulphur Bank Mercury Mine (SBMM), active intermittently from 1873–1957 and now a USEPA Superfund site, was previously estimated to have contributed at least 100 metric tons (105 kg) of mercury (Hg) into the Clear Lake aquatic ecosystem. We have confirmed this minimum estimate. To better quantify the contribution of the mine in relation to other sources of Hg loading into Clear Lake and provide data that might help reduce that loading, we analyzed Inputs and Outputs of Hg to Clear Lake and Storage of Hg in lakebed sediments using a mass balance approach. We evaluated Inputs from (1) wet and dry atmospheric deposition from both global/regional and local sources, (2) watershed tributaries, (3) groundwater inflows, (4) lakebed springs and (5) the mine. Outputs were quantified from (1) efflux (volatilization) of Hg from the lake surface to the atmosphere, (2) municipal and agricultural water diversions, (3) losses from out-flowing drainage of Cache Creek that feeds into the California Central Valley and (4) biotic Hg removal by humans and wildlife. Storage estimates include (1) sediment burial from historic and prehistoric periods (over the past 150–3,000 years) from sediment cores to ca. 2.5m depth dated using dichloro diphenyl dichloroethane (DDD), 210Pb and 14C and (2) recent Hg deposition in surficial sediments. Surficial sediments collected in October 2003 (11 years after mine site remediation) indicate no reduction (but a possible increase) in sediment Hg concentrations over that time and suggest that remediation has not significantly reduced overall Hg loading to the lake. Currently, the mine is believed to contribute ca. 322–331 kg of Hg annually to Clear Lake, which represents ca. 86–99% of the total Hg loading to the lake. We estimate that natural sedimentation would cover the existing contaminated sediments within ca. 150–300 years.

Assessment of the Great Lakes Marine Renewable Energy Resources: Characterizing Lake Erie Surge, Seiche and Waves

NASA Astrophysics Data System (ADS)

Farhadzadeh, A.; Hashemi, M. R.

2016-02-01

Lake Erie, the fourth largest in surface area, smallest in volume and shallowest among the Great Lakes is approximately 400 km long and 90 km wide. Short term lake level variations are due to storm surge generated by high winds and moving pressure systems over the lake mainly in the southwest-northeast direction, along the lakes longitudinal axis. The historical wave data from three active offshore buoys shows that significant wave height can exceed 5 m in the eastern and central basins. The long-term lake level data show that storm surge can reach up to 3 m in eastern Lake Erie. Owing its shallow depth, Lake Erie frequently experiences seiching motions, the low frequency oscillations that are initiated by storm surge. The seiches whose first mode of oscillations has a period of nearly 14.2 hours can last from several hours to days. In this study, the Lake Erie potential for power generation, primarily using storm surge and seiche and also waves are assessed. Given the cyclic lake level variations due to storm-induced seiching, a concept similar to that of tidal range development is utilized to assess the potential of storm surge and seiche energy harvesting mechanisms for power generation. In addition, wave energy resources of the Lake is characterized -. To achieve these objectives, the following steps are taken : (1) Frequency of occurrence for extreme storm surge and wave events is determined using extreme value analysis such as Peak-Over-Threshold method for the long-term water level and wave data; (2) Spatial and temporal variations of wave height, storm surge and seiche are characterized. The characterization is carried out using the wave and storm surge outputs from numerical simulation of a number of historical extreme events. The coupled ADCIRC and SWAN model is utilized for the modeling; (3) Assessment of the potentials for marine renewable power generation in Lake Erie is made. The approach can be extended to the other lakes in the Great Lakes region.

Assessment of the service performance of drainage system and transformation of pipeline network based on urban combined sewer system model.

PubMed

Peng, Hai-Qin; Liu, Yan; Wang, Hong-Wu; Ma, Lu-Ming

2015-10-01

In recent years, due to global climate change and rapid urbanization, extreme weather events occur to the city at an increasing frequency. Waterlogging is common because of heavy rains. In this case, the urban drainage system can no longer meet the original design requirements, resulting in traffic jams and even paralysis and post a threat to urban safety. Therefore, it provides a necessary foundation for urban drainage planning and design to accurately assess the capacity of the drainage system and correctly simulate the transport effect of drainage network and the carrying capacity of drainage facilities. This study adopts InfoWorks Integrated Catchment Management (ICM) to present the two combined sewer drainage systems in Yangpu District, Shanghai (China). The model can assist the design of the drainage system. Model calibration is performed based on the historical rainfall events. The calibrated model is used for the assessment of the outlet drainage and pipe loads for the storm scenario currently existing or possibly occurring in the future. The study found that the simulation and analysis results of the drainage system model were reliable. They could fully reflect the service performance of the drainage system in the study area and provide decision-making support for regional flood control and transformation of pipeline network.

Surge dynamics and lake outbursts of Kyagar Glacier, Karakoram

NASA Astrophysics Data System (ADS)

Round, Vanessa; Leinss, Silvan; Huss, Matthias; Haemmig, Christoph; Hajnsek, Irena

2017-03-01

The recent surge cycle of Kyagar Glacier, in the Chinese Karakoram, caused formation of an ice-dammed lake and subsequent glacial lake outburst floods (GLOFs) exceeding 40 million m3 in 2015 and 2016. GLOFs from Kyagar Glacier reached double this size in 2002 and earlier, but the role of glacier surging in GLOF formation was previously unrecognised. We present an integrative analysis of the glacier surge dynamics from 2011 to 2016, assessing surge mechanisms and evaluating the surge cycle impact on GLOFs. Over 80 glacier surface velocity fields were created from TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement), Sentinel-1A, and Landsat satellite data. Changes in ice thickness distribution were revealed by a time series of TanDEM-X elevation models. The analysis shows that, during a quiescence phase lasting at least 14 years, ice mass built up in a reservoir area at the top of the glacier tongue, and the terminus thinned by up to 100 m, but in the 2 years preceding the surge onset this pattern reversed. The surge initiated with the onset of the 2014 melt season, and in the following 15 months velocity evolved in a manner consistent with a hydrologically controlled surge mechanism. Dramatic accelerations coincided with melt seasons, winter deceleration was accompanied by subglacial drainage, and rapid surge termination occurred following the 2015 GLOF. Rapid basal motion during the surge is seemingly controlled by high water pressure, caused by input of surface water into either an inefficient subglacial drainage system or unstable subglacial till. The potential lake volume increased to more than 70 million m3 by late 2016, as a result of over 60 m of thickening at the terminus. Lake formation and the evolution of the ice dam height should be carefully monitored through remote sensing to anticipate large GLOFs in the near future.

Bathymetry of Lake Manatee, Manatee County, Florida, 2009

USGS Publications Warehouse

Bellino, Jason C.; Pfeiffer, William R.

2010-01-01

Lake Manatee, located in central Manatee County, Florida, is the principal drinking-water source for Manatee and Sarasota Counties. The drainage basin of Lake Manatee encompasses about 120 square miles, and the reservoir covers a surface area of about 1,450 acres at an elevation of 38.8 feet above NAVD 88 or 39.7 feet above NGVD 29. The full pool water-surface elevation is 39.1 feet above NAVD 88 (40.0 feet above NGVD 29), and the estimated minimum usable elevation is 25.1 feet above NAVD 88 (26.0 feet above NGVD 29). The minimum usable elevation is based on the elevation of water intake structures. Manatee County has used the stage/volume relation that was developed from the original survey in the 1960s to estimate the volume of water available for consumption. Concerns about potential changes in storage capacity of the Lake Manatee reservoir, coupled with a recent drought, led to this bathymetry mapping effort.

Spatial and historical distribution of organic phosphorus driven by environment conditions in lake sediments.

PubMed

Lü, Changwei; He, Jiang; Wang, Bing

2018-02-01

The chemistry of sedimentary organic phosphorus (OP) and its fraction distribution in sediments are greatly influenced by environmental conditions such as terrestrial inputs and runoffs. The linkage of OP with environmental conditions was analyzed on the basis of OP spatial and historical distributions in lake sediments. The redundancy analysis and OP spatial distribution results suggested that both NaOH-OP (OP extracted by NaOH) and Re-OP (residual OP) in surface sediments from the selected 13 lakes reflected the gradient effects of environmental conditions and the autochthonous and/or allochthonous inputs driven by latitude zonality in China. The lake level and salinity of Lake Hulun and the runoff and precipitation of its drainage basin were reconstructed on the basis of the geochemistry index. This work showed that a gradient in weather conditions presented by the latitude zonality in China impacts the OP accumulation through multiple drivers and in many ways. The drivers are mainly precipitation and temperature, governing organic matter (OM) production, degradation rate and transportation in the watershed. Over a long temporal dimension (4000years), the vertical distributions of Re-OP and NaOH-OP based on a dated sediment profile from HLH were largely regulated by the autochthonous and/or allochthonous inputs, which depended on the environmental and climate conditions and anthropogenic activities in the drainage basin. This work provides useful environmental geochemistry information to understand the inherent linkage of OP fractionation with environmental conditions and lake evolution. Copyright © 2017. Published by Elsevier B.V.

Streamflow and water-quality data for three major tributaries to Reelfoot Lake, west Tennessee, October 1987-March 1988

USGS Publications Warehouse

Yurewicz, M.C.; Carey, W.P.; Garrett, J.W.

1988-01-01

Streamflow and water quality data were collected for three major tributaries to Reelfoot Lake, in West Tennessee, for the period October 1987 through March 1988. The data are presented in graphs and tables. Mean daily discharge data were collected at one site each in the drainage basins of North Reelfoot Creek, South Reelfoot Creek, and Running Slough. Daily mean suspended-sediment concentration data were collected at a site in the North Reelfoot Creek basin. Water quality samples were collected during storm events at the same locations that daily mean streamflow data were collected. Water quality samples were analyzed for concentrations of nutrients and triazine herbicides. Water temperature and specific conductance were measured at the time that samples were collected. (USGS)

Estimation of nonpoint source loadings of phosphorus for lakes in the Puget Sound region, Washington

USGS Publications Warehouse

Gilliom, Robert J.

1983-01-01

Control of eutrophication of lakes in watersheds undergoing development is facilitated by estimates of the amounts of phosphorus (P) that reach the lakes from areas under various types of land use. Using a mass-balance model, the author calculated P loadings from present-day P concentrations measured in lake water and from other easily measured physical characteristics in a total of 28 lakes in drainage basins that contain only forest and residential land. The loadings from background sources (forest-land drainage and bulk precipitation) to each of the lakes were estimated by methods developed in a previous study. Differences between estimated present-day P loadings and loadings from background sources were attributed to changes in land use. The mean increase in annual P yield resulting from conversion of forest to residential land use was 7 kilograms per square kilometer, not including septic tank system contributions. Calculated loadings from septic systems were found to correlate best with the number of near-shore dwellings around each lake in 1940. The regression equation expressing this relationship explained 36 percent of the sample variance. There was no significant correlation between estimated septic tank system P loadings and number of dwellings present in 1960 or 1970. The evidence indicates that older systems might contribute more phosphorus to lakes than newer systems, and that there may be substantial time lags between septic system installation and significant impacts on lake-water P concentrations. For lakes in basins that contain agricultural land, the P loading attributable to agriculture can be calculated as the difference between the estimated total loading and the sum of estimated loadings from nonagricultural sources. A comprehensive system for evaluating errors in all loading estimates is presented. The empirical relationships developed allow preliminary approximations of the cumulative impact development has had on P loading and the amounts

Nitrogen limitation, toxin synthesis potential, and toxicity of cyanobacterial populations in Lake Okeechobee and the St. Lucie River Estuary, Florida, during the 2016 state of emergency event.

PubMed

Kramer, Benjamin J; Davis, Timothy W; Meyer, Kevin A; Rosen, Barry H; Goleski, Jennifer A; Dick, Gregory J; Oh, Genesok; Gobler, Christopher J

2018-01-01

Lake Okeechobee, FL, USA, has been subjected to intensifying cyanobacterial blooms that can spread to the adjacent St. Lucie River and Estuary via natural and anthropogenically-induced flooding events. In July 2016, a large, toxic cyanobacterial bloom occurred in Lake Okeechobee and throughout the St. Lucie River and Estuary, leading Florida to declare a state of emergency. This study reports on measurements and nutrient amendment experiments performed in this freshwater-estuarine ecosystem (salinity 0-25 PSU) during and after the bloom. In July, all sites along the bloom exhibited dissolved inorganic nitrogen-to-phosphorus ratios < 6, while Microcystis dominated (> 95%) phytoplankton inventories from the lake to the central part of the estuary. Chlorophyll a and microcystin concentrations peaked (100 and 34 μg L-1, respectively) within Lake Okeechobee and decreased eastwards. Metagenomic analyses indicated that genes associated with the production of microcystin (mcyE) and the algal neurotoxin saxitoxin (sxtA) originated from Microcystis and multiple diazotrophic genera, respectively. There were highly significant correlations between levels of total nitrogen, microcystin, and microcystin synthesis gene abundance across all surveyed sites (p < 0.001), suggesting high levels of nitrogen supported the production of microcystin during this event. Consistent with this, experiments performed with low salinity water from the St. Lucie River during the event indicated that algal biomass was nitrogen-limited. In the fall, densities of Microcystis and concentrations of microcystin were significantly lower, green algae co-dominated with cyanobacteria, and multiple algal groups displayed nitrogen-limitation. These results indicate that monitoring and regulatory strategies in Lake Okeechobee and the St. Lucie River and Estuary should consider managing loads of nitrogen to control future algal and microcystin-producing cyanobacterial blooms.

An Abrupt Centennial-Scale Drought Event and Mid-Holocene Climate Change Patterns in Monsoon Marginal Zones of East Asia

PubMed Central

Li, Yu; Wang, Nai'ang; Zhang, Chengqi

2014-01-01

The mid-latitudes of East Asia are characterized by the interaction between the Asian summer monsoon and the westerly winds. Understanding long-term climate change in the marginal regions of the Asian monsoon is critical for understanding the millennial-scale interactions between the Asian monsoon and the westerly winds. Abrupt climate events are always associated with changes in large-scale circulation patterns; therefore, investigations into abrupt climate changes provide clues for responses of circulation patterns to extreme climate events. In this paper, we examined the time scale and mid-Holocene climatic background of an abrupt dry mid-Holocene event in the Shiyang River drainage basin in the northwest margin of the Asian monsoon. Mid-Holocene lacustrine records were collected from the middle reaches and the terminal lake of the basin. Using radiocarbon and OSL ages, a centennial-scale drought event, which is characterized by a sand layer in lacustrine sediments both from the middle and lower reaches of the basin, was absolutely dated between 8.0–7.0 cal kyr BP. Grain size data suggest an abrupt decline in lake level and a dry environment in the middle reaches of the basin during the dry interval. Previous studies have shown mid-Holocene drought events in other places of monsoon marginal zones; however, their chronologies are not strong enough to study the mechanism. According to the absolutely dated records, we proposed a new hypothesis that the mid-Holocene dry interval can be related to the weakening Asian summer monsoon and the relatively arid environment in arid Central Asia. Furthermore, abrupt dry climatic events are directly linked to the basin-wide effective moisture change in semi-arid and arid regions. Effective moisture is affected by basin-wide precipitation, evapotranspiration, lake surface evaporation and other geographical settings. As a result, the time scales of the dry interval could vary according to locations due to different

An abrupt centennial-scale drought event and mid-holocene climate change patterns in monsoon marginal zones of East Asia.

PubMed

Li, Yu; Wang, Nai'ang; Zhang, Chengqi

2014-01-01

The mid-latitudes of East Asia are characterized by the interaction between the Asian summer monsoon and the westerly winds. Understanding long-term climate change in the marginal regions of the Asian monsoon is critical for understanding the millennial-scale interactions between the Asian monsoon and the westerly winds. Abrupt climate events are always associated with changes in large-scale circulation patterns; therefore, investigations into abrupt climate changes provide clues for responses of circulation patterns to extreme climate events. In this paper, we examined the time scale and mid-Holocene climatic background of an abrupt dry mid-Holocene event in the Shiyang River drainage basin in the northwest margin of the Asian monsoon. Mid-Holocene lacustrine records were collected from the middle reaches and the terminal lake of the basin. Using radiocarbon and OSL ages, a centennial-scale drought event, which is characterized by a sand layer in lacustrine sediments both from the middle and lower reaches of the basin, was absolutely dated between 8.0-7.0 cal kyr BP. Grain size data suggest an abrupt decline in lake level and a dry environment in the middle reaches of the basin during the dry interval. Previous studies have shown mid-Holocene drought events in other places of monsoon marginal zones; however, their chronologies are not strong enough to study the mechanism. According to the absolutely dated records, we proposed a new hypothesis that the mid-Holocene dry interval can be related to the weakening Asian summer monsoon and the relatively arid environment in arid Central Asia. Furthermore, abrupt dry climatic events are directly linked to the basin-wide effective moisture change in semi-arid and arid regions. Effective moisture is affected by basin-wide precipitation, evapotranspiration, lake surface evaporation and other geographical settings. As a result, the time scales of the dry interval could vary according to locations due to different geographical

Empirical estimation of recreational exploitation of burbot, Lota lota, in the Wind River drainage of Wyoming using a multistate capture–recapture model

USGS Publications Warehouse

Lewandoski, S. A.; Guy, Christopher S.; Zale, Alexander V.; Gerrity, Paul C.; Deromedi, J. W.; Johnson, K.M.; Skates, D. L.

2017-01-01

Burbot, Lota lota (Linnaeus), is a regionally popular sportfish in the Wind River drainage of Wyoming, USA, at the southern boundary of the range of the species. Recent declines in burbot abundances were hypothesised to be caused by overexploitation, entrainment in irrigation canals and habitat loss. This study addressed the overexploitation hypothesis using tagging data to generate reliable exploitation, abundance and density estimates from a multistate capture–recapture model that accounted for incomplete angler reporting and tag loss. Exploitation rate μ was variable among the study lakes and inversely correlated with density. Exploitation thresholds μ40 associated with population densities remaining above 40% of carrying capacity were generated to characterise risk of overharvest using exploitation and density estimates from tagging data and a logistic surplus-production model parameterised with data from other burbot populations. Bull Lake (μ = 0.06, 95% CI: 0.03–0.11; μ40 = 0.18) and Torrey Lake (μ = 0.02, 95% CI: 0.00–0.11; μ40 = 0.18) had a low risk of overfishing, Upper Dinwoody Lake had intermediate risk (μ = 0.08, 95% CI: 0.02–0.32; μ40 = 0.18) and Lower Dinwoody Lake had high risk (μ = 0.32, 95% CI: 0.10–0.67; μ40 = 0.08). These exploitation and density estimates can be used to guide sustainable management of the Wind River drainage recreational burbot fishery and inform management of other burbot fisheries elsewhere.

Peritoneal Drainage Versus Pleural Drainage After Pediatric Cardiac Surgery.

PubMed

Gowda, Keshava Murty Narayana; Zidan, Marwan; Walters, Henry L; Delius, Ralph E; Mastropietro, Christopher W

2014-07-01

We aimed to determine whether infants undergoing cardiac surgery would more efficiently attain negative fluid balance postoperatively with passive peritoneal drainage as compared to traditional pleural drainage. A prospective, randomized study including children undergoing repair of tetralogy of Fallot (TOF) or atrioventricular septal defect (AVSD) was completed between September 2011 and June 2013. Patients were randomized to intraoperative placement of peritoneal catheter or right pleural tube in addition to the requisite mediastinal tube. The primary outcome measure was fluid balance at 48 hours postoperatively. Variables were compared using t tests or Fisher exact tests as appropriate. A total of 24 patients were enrolled (14 TOF and 10 AVSD), with 12 patients in each study group. Mean fluid balance at 48 hours was not significantly different between study groups, -41 ± 53 mL/kg in patients with periteonal drainage and -9 ± 40 mL/kg in patients with pleural drainage (P = .10). At 72 hours however, postoperative fluid balance was significantly more negative with peritoneal drainage, -52.4 ± 71.6 versus +2.0 ± 50.6 (P = .04). On subset analysis, fluid balance at 48 hours in patients with AVSD was more negative with peritoneal drainage as compared to pleural, -82 ± 51 versus -1 ± 38 mL/kg, respectively (P = .02). Fluid balance at 48 hours in patients with TOF was not significantly different between study groups. Passive peritoneal drainage may more effectively facilitate negative fluid balance when compared to pleural drainage after pediatric cardiac surgery, although this benefit is not likely universal but rather dependent on the patient's underlying physiology. © The Author(s) 2014.

Landscape influences on climate-related lake shrinkage at high latitudes

USGS Publications Warehouse

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

2013-01-01

Climate-related declines in lake area have been identified across circumpolar regions and have been characterized by substantial spatial heterogeneity. An improved understanding of the mechanisms underlying lake area trends is necessary to predict where change is most likely to occur and to identify implications for high latitude reservoirs of carbon. Here, using a population of ca. 2300 lakes with statistically significant increasing and decreasing lake area trends spanning longitudinal and latitudinal gradients of ca. 1000 km in Alaska, we present evidence for a mechanism of lake area decline that involves the loss of surface water to groundwater systems. We show that lakes with significant declines in lake area were more likely to be located: (1) in burned areas; (2) on coarser, well-drained soils; and (3) farther from rivers compared to lakes that were increasing. These results indicate that postfire processes such as permafrost degradation, which also results from a warming climate, may promote lake drainage, particularly in coarse-textured soils and farther from rivers where overland flooding is less likely and downslope flow paths and negative hydraulic gradients between surface water and groundwater systems are more common. Movement of surface water to groundwater systems may lead to a deepening of subsurface flow paths and longer hydraulic residence time which has been linked to increased soil respiration and CO2 release to the atmosphere. By quantifying relationships between statewide coarse resolution maps of landscape characteristics and spatially heterogeneous responses of lakes to environmental change, we provide a means to identify at-risk lakes and landscapes and plan for a changing climate.

Large basal crevasses as a proxy for historic subglacial flooding events on Byrd Glacier

NASA Astrophysics Data System (ADS)

Child, S. F.; Stearns, L. A.; van der Veen, C. J.; Hamilton, G. S.

2016-12-01

Active networks of subglacial lakes have recently been found beneath the Antarctic Ice Sheet. On Byrd Glacier, East Antarctica, a subglacial lake outburst event in 2005/07 led to a short-lived glacier acceleration. Due to the sparse record of historical observations, it is unclear how frequently these outburst events occur, and the role they play in the dynamics of Antarctic outlet glaciers. Crevasses form when the tensile stress is greater than the fracture strength of ice. High extensional strain rates often exist at the grounding line where grounded ice begins to float. We hypothesize that the formation of anomalously large basal crevasses coincides with the higher strain rates observed during flooding events. In this study, we use the location of large basal crevasses ( 330 m tall), located along the floating portion of the Byrd Glacier flowline, to create a timeline of past flooding events. We first model crevasse formation to demonstrate that basal crevasses likely form at the grounding line. To do this, we use linear elastic fracture mechanics (LEFM) to estimate crevasse heights based on strain rates during known flood (300-350 m) and non-flood (100-150 m) time periods at Byrd Glacier's grounding line. Basal crevasse locations and heights are determined directly from radar echograms (2011/12 CReSIS radar data and 1974/75 SPRI NSF TUD radar data) along the Byrd Glacier flowline. We also use the locations of large surface depressions to infer the presence of basal crevasses. When crevasses penetrate a threshold proportion of the ice column, the overlying ice is no longer supported and a surface depression forms. We identify 22 large basal crevasses through these combined methods; the oldest crevasse likely formed 600 years ago. This research provides a framework of Antarctic subglacial flooding frequency and the effects that subglacial water drainage events have on outlet glacier dynamics.

Modeling a Glacial Lake Outburst Flood Process Chain: The Case of Lake Palcacocha and Huaraz, Peru

NASA Astrophysics Data System (ADS)

Chisolm, Rachel; Somos-Valenzuela, Marcelo; Rivas Gomez, Denny; McKinney, Daene C.; Portocarrero Rodriguez, Cesar

2016-04-01

One of the consequences of recent glacier recession in the Cordillera Blanca, Peru, is the risk of Glacial Lake Outburst Floods (GLOFs) from lakes that have formed at the base of retreating glaciers. GLOFs are often triggered by avalanches falling into glacial lakes, initiating a chain of processes that may culminate in significant inundation and destruction downstream. This paper presents simulations of all of the processes involved in a potential GLOF originating from Lake Palcacocha, the source of a previously catastrophic GLOF on December 13, 1941, 1800 people in the city of Huaraz, Peru. The chain of processes simulated here includes: (1) avalanches above the lake; (2) lake dynamics resulting from the avalanche impact, including wave generation, propagation, and run-up across lakes; (3) terminal moraine overtopping and dynamic moraine erosion simulations to determine the possibility of breaching; (4) flood propagation along downstream valleys; and (5) inundation of populated areas. The results of each process feed into simulations of subsequent processes in the chain, finally resulting in estimates of inundation in the city of Huaraz. The results of the inundation simulations were converted into flood intensity and hazard maps (based on an intensity-likelihood matrix) that may be useful for city planning and regulation. Three avalanche events with volumes ranging from 0.5-3 x 106 m3 were simulated, and two scenarios of 15 m and 30 m lake lowering were simulated to assess the potential of mitigating the hazard level in Huaraz. For all three avalanche events, three-dimensional hydrodynamic models show large waves generated in the lake from the impact resulting in overtopping of the damming-moraine. Despite very high discharge rates (up to 63.4 x 103 m3/s), the erosion from the overtopping wave did not result in failure of the damming-moraine when simulated with a hydro-morphodynamic model using excessively conservative soil characteristics that provide very

Modeling a glacial lake outburst flood process chain: the case of Lake Palcacocha and Huaraz, Peru

NASA Astrophysics Data System (ADS)

Somos-Valenzuela, Marcelo A.; Chisolm, Rachel E.; Rivas, Denny S.; Portocarrero, Cesar; McKinney, Daene C.

2016-07-01

One of the consequences of recent glacier recession in the Cordillera Blanca, Peru, is the risk of glacial lake outburst floods (GLOFs) from lakes that have formed at the base of retreating glaciers. GLOFs are often triggered by avalanches falling into glacial lakes, initiating a chain of processes that may culminate in significant inundation and destruction downstream. This paper presents simulations of all of the processes involved in a potential GLOF originating from Lake Palcacocha, the source of a previously catastrophic GLOF on 13 December 1941, killing about 1800 people in the city of Huaraz, Peru. The chain of processes simulated here includes (1) avalanches above the lake; (2) lake dynamics resulting from the avalanche impact, including wave generation, propagation, and run-up across lakes; (3) terminal moraine overtopping and dynamic moraine erosion simulations to determine the possibility of breaching; (4) flood propagation along downstream valleys; and (5) inundation of populated areas. The results of each process feed into simulations of subsequent processes in the chain, finally resulting in estimates of inundation in the city of Huaraz. The results of the inundation simulations were converted into flood intensity and preliminary hazard maps (based on an intensity-likelihood matrix) that may be useful for city planning and regulation. Three avalanche events with volumes ranging from 0.5 to 3 × 106 m3 were simulated, and two scenarios of 15 and 30 m lake lowering were simulated to assess the potential of mitigating the hazard level in Huaraz. For all three avalanche events, three-dimensional hydrodynamic models show large waves generated in the lake from the impact resulting in overtopping of the damming moraine. Despite very high discharge rates (up to 63.4 × 103 m3 s-1), the erosion from the overtopping wave did not result in failure of the damming moraine when simulated with a hydro-morphodynamic model using excessively conservative soil

Pleistocene lake outburst floods and fan formation along the eastern Sierra Nevada, California: implications for the interpretation of intermontane lacustrine records

NASA Astrophysics Data System (ADS)

Benn, Douglas I.; Owen, Lewis A.; Finkel, Robert C.; Clemmens, Samuel

2006-11-01

Variations in the rock flour fraction in intermontane lacustrine sediments have the potential to provide more complete records of glacier fluctuations than moraine sequences, which are subject to erosional censoring. Construction of glacial chronologies from such records relies on the assumption that rock flour concentration is a simple function of glacier extent. However, other factors may influence the delivery of glacigenic sediments to intermontane lakes, including paraglacial adjustment of slope and fluvial systems to deglaciation, variations in precipitation and snowmelt, and lake outburst floods. We have investigated the processes and chronology of sediment transport on the Tuttle and Lone Pine alluvial fans in the eastern Sierra Nevada, California, USA, to elucidate the links between former glacier systems located upstream and the long sedimentary record from Owens Lake located downstream. Aggradation of both fans reflects sedimentation by three contrasting process regimes: (1) high magnitude, catastrophic floods, (2) fluvial or glacifluvial river systems, and (3) debris flows and other slope processes. Flood deposits are represented by multiple boulder beds exposed in section, and extensive networks of large palaeochannels and boulder deposits on both fan surfaces. Palaeohydrological analysis implies peak discharges in the order of 10 3-10 4 m 3 s -1, most probably as the result of catastrophic drainage of ice-, moraine-, and landslide-dammed lakes. Cosmogenic radionuclide surface exposure dating shows that at least three flood events are represented on each fan, at 9-13, 16-18 and 32-44 ka (Tuttle Fan); and at ˜23-32, ˜80-86 ka, and a poorly constrained older event (Lone Pine Fan). Gravels and sands exposed in both fans represent fluvial and/or glacifluvial sediment transport from the Sierra Nevada into Owens Valley, and show that river systems incised and reworked older sediment stored in the fans. We argue that millennial-scale peaks in rock flour

[Microeukaryotic biodiversity in the waste ore samples surrounding an acid mine drainage lake].

PubMed

Li, Si-Yuan; Hao, Chun-Bo; Wang, Li-Hua; Lü, Zheng; Zhang, Li-Na; Liu, Ying; Feng, Chuan-Ping

2013-10-01

The abandoned mineral samples were collected in an acid mine drainage area in Anhui Province. Molecular ecological methods were used to construct 18S rDNA clone libraries after analyzing the main physicochemical parameters, and then the microeukaryotic diversity and community structure in the acid mine drainage area were studied. The results showed that the region was strongly acidic (pH <3), and the concentrations of Fe, SO2-(4), P, NO-(3) -N showed the same trend, all higher in the bare waste ore samples PD and 1 M than in the vegetation covered samples LW and XC. Four eukaryotic phyla were detected in the abandoned mineral samples: Ascomycota, Basidiomycota, Glomeromycota and Arthropoda. Glomeromycota can form an absolute symbiotic relationship with the plant, and it was a key factor for early plant to adapt the terrestrial environment. The biodiversity of the vegetation covered samples LW and XC, which contained Glomeromycota, was much higher than that of the bare abandoned rock samples PD and 1 M. Moreover, many sequences in the libraries were closely related to some isolated strains, which are tolerant to low pH and heavy metals, such as Penicillium purpurogenum, Chaetothyriales sp. and Staninwardia suttonii.

Volcano and earthquake hazards in the Crater Lake region, Oregon

USGS Publications Warehouse

Bacon, Charles R.; Mastin, Larry G.; Scott, Kevin M.; Nathenson, Manuel

1997-01-01

Crater Lake lies in a basin, or caldera, formed by collapse of the Cascade volcano known as Mount Mazama during a violent, climactic eruption about 7,700 years ago. This event dramatically changed the character of the volcano so that many potential types of future events have no precedent there. This potentially active volcanic center is contained within Crater Lake National Park, visited by 500,000 people per year, and is adjacent to the main transportation corridor east of the Cascade Range. Because a lake is now present within the most likely site of future volcanic activity, many of the hazards at Crater Lake are different from those at most other Cascade volcanoes. Also significant are many faults near Crater Lake that clearly have been active in the recent past. These faults, and historic seismicity, indicate that damaging earthquakes can occur there in the future. This report describes the various types of volcano and earthquake hazards in the Crater Lake area, estimates of the likelihood of future events, recommendations for mitigation, and a map of hazard zones. The main conclusions are summarized below.

Simulation of climate-change effects on streamflow, lake water budgets, and stream temperature using GSFLOW and SNTEMP, Trout Lake Watershed, Wisconsin

USGS Publications Warehouse

Hunt, Randall J.; Walker, John F.; Selbig, William R.; Westenbroek, Stephen M.; Regan, R. Steve

2013-01-01

-fed systems. Seepage lakes showed larger forecast stage declines related to climate change than did drainage lakes (lakes with outlet streams). Seepage lakes higher in the watershed (nearer to groundwater divides) had less groundwater inflow and thus had larger forecast declines in lake stage; however, ground-water inflow to seepage lakes in general tended to increase as a fraction of the lake budgets with lake-stage decline because inward hydraulic gradients increased. Drainage lakes were characterized by less simulated stage decline as reductions in outlet streamflow of set losses to other water flows. Net groundwater inflow tended to decrease in drainage lakes over the scenario period. Simulated stream temperatures increased appreciably with climate change. The estimated increase in annual average temperature ranged from approximately 1 to 2 degrees Celsius by 2100 in the stream characterized by a high groundwater inflow rate and 2 to 3 degrees Celsius in the stream with a lower rate. The climate drivers used for the climate-change scenarios had appreciable variation between the General Circulation Model and emission scenario selected; this uncertainty was reflected in hydrologic flow and temperature model results. Thus, as with all forecasts of this type, the results are best considered to approximate potential outcomes of climate change.

The potential for catastrophic dam failure at Lake Nyos maar, Cameroon

USGS Publications Warehouse

Lockwood, J.P.; Costa, J.E.; Tuttle, M.L.; Nni, J.; Tebor, S.G.

1988-01-01

The upper 40 m of Lake Nyos is bounded on the north by a narrow dam of poorly consolidated pyroclastic rocks, emplaced during the eruptive formation of the Lake Nyos maar a few hundred years ago. This 50-m-wide natural dam is structurally weak and is being eroded at an uncertain, but geologically alarming, rate. The eventual failure of the dam could cause a major flood (estimated peak discharge, 17000 m3/s) that would have a tragic impact on downstream areas as far as Nigeria, 108 km away. This serious hazard could be eliminated by lowering the lake level, either by controlled removal of the dam or by construction of a 680-m-long drainage tunnel about 65 m below the present lake surface. Either strategy would also lessen the lethal effects of future massive CO2 gas releases, such as the one that occurred in August 1986. ?? 1988 Springer-Verlag.

Anthropogenic modifications to drainage conditions on streamflow variability in the Wabash River basin, Indiana

NASA Astrophysics Data System (ADS)

Chiu, C.; Bowling, L. C.

2011-12-01

The Wabash River watershed is the largest watershed in Indiana and includes the longest undammed river reach east of the Mississippi River. The land use of the Wabash River basin began to significantly change from mixed woodland dominated by small lakes and wetlands to agriculture in the mid-1800s and agriculture is now the predominant land use. Over 80% of natural wetland areas were drained to facilitate better crop production through both surface and subsurface drainage applications. Quantifying the change in hydrologic response in this intensively managed landscape requires a hydrologic model that can represent wetlands, crop growth, and impervious area as well as subsurface and surface drainage enhancements, coupled with high resolution soil and topographic inputs. The Variable Infiltration Capacity (VIC) model wetland algorithm has been previously modified to incorporate spatially-varying estimates of water table distribution using a topographic index approach, as well as a simple urban representation. Now, the soil water characteristics curve and a derived drained to equilibrium moisture profile are used to improve the model's estimation of the water table. In order to represent subsurface (tile) drainage, the tile drainage component of subsurface flow is calculated when the simulated water table rises above a specified drain depth. A map of the current estimated extent of subsurface tile drainage for the Wabash River based on a decision tree classifier of soil drainage class, soil slope and agricultural land use is used to activate the new tile drainage feature in the VIC model, while wetland depressional storage capacity is extracted from digital elevation and soil information. This modified VIC model is used to evaluate the performance of model physical variations in the intensively managed hydrologic regime of the Wabash River system and to understand the role of surface and subsurface storage, and land use and land cover change on hydrologic change.

Founding events influence genetic population structure of sockeye salmon (Oncorhynchus nerka) in Lake Clark, Alaska

USGS Publications Warehouse

Ramstad, K.M.; Woody, C.A.; Sage, G.K.; Allendorf, F.W.

2004-01-01

Bottlenecks can have lasting effects on genetic population structure that obscure patterns of contemporary gene flow and drift. Sockeye salmon are vulnerable to bottleneck effects because they are a highly structured species with excellent colonizing abilities and often occupy geologically young habitats. We describe genetic divergence among and genetic variation within spawning populations of sockeye salmon throughout the Lake Clark area of Alaska. Fin tissue was collected from sockeye salmon representing 15 spawning populations of Lake Clark, Six-mile Lake, and Lake Iliamna. Allele frequencies differed significantly at 11 microsatellite loci in 96 of 105 pairwise population comparisons. Pairwise estimates of FST ranged from zero to 0.089. Six-mile Lake and Lake Clark populations have historically been grouped together for management purposes and are geographically proximate. However, Six-mile Lake populations are genetically similar to Lake Iliamna populations and are divergent from Lake Clark populations. The reduced allelic diversity and strong divergence of Lake Clark populations relative to Six-mile Lake and Lake Iliamna populations suggest a bottleneck associated with the colonization of Lake Clark by sockeye salmon. Geographic distance and spawning habitat differences apparently do not contribute to isolation and divergence among populations. However, temporal isolation based on spawning time and founder effects associated with ongoing glacial retreat and colonization of new spawning habitats contribute to the genetic population structure of Lake Clark sock-eye salmon. Nonequilibrium conditions and the strong influence of genetic drift caution against using estimates of divergence to estimate gene flow among populations of Lake Clark sockeye salmon.

Peak-flow frequency and extreme flood potential for streams in the vicinity of the Highland Lakes, central Texas

USGS Publications Warehouse

Asquith, William H.; Slade, R.M.; Lanning-Rush, Jennifer

1996-01-01

The Highland Lakes on the Colorado River are in an area periodically threatened by large storms and floods. Many storms exceeding 10 inches (in.) in depth have been documented in the area, including some with depths approaching 40 in. These storms typically produce large peak discharges that often threaten lives and property. The storms sometimes occur with little warning. Steep stream slopes and thin soils characteristic of the area often cause large peak discharges and rapid movement of floods through watersheds. A procedure to predict the discharge associated with large floods is needed for the area so that appropriate peak discharges can be used in the design of flood plains, bridges, and other structures.The U.S. Geological Survey (USGS), in cooperation with the Lower Colorado River Authority (LCRA), studied flood peaks for streams in the vicinity of the Highland Lakes of central Texas. The Highland Lakes are a series of reservoirs constructed on the Colorado River. The chain of lakes (and year each was completed) comprises Lake Buchanan (1937), Inks Lake (1938), Lake Lyndon B. Johnson (1950), Lake Marble Falls (1951), Lake Travis (1942), and lake Austin (1890). The study area (fig. 1), which includes all or parts of 21 counties in the vicinity of the Highland Lakes, was selected because most streams in the area have flood characteristics similar to streams entering the Highland Lakes. The entire study area is in a region subject to large storms.The purpose of this report is to present (1) peak-flow frequency data for stations and equations to estimate peak-flow frequency for large streams with natural drainage basins in the vicinity of the Highland Lakes, and (2) a technique to estimate the extreme flood peak discharges for the large streams in the vicinity of the Highland Lakes. Peak-flow frequency in this report refers to the peak discharges for recurrence intervals of 2,5, 10,25,50, and 100 years. A large stream is defined as having a contributing drainage

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

Wisconsin's Lake Superior Basin Water Quality Study. Supplement. Technical Report No. 2.

ERIC Educational Resources Information Center

Whisnant, David M., Ed.

During the period extending from May 1972 through April 1973, an investigation of the overall water quality conditions of streams flowing into Lake Superior from the entire state of Wisconsin was conducted. The goal of this publication was to provide much needed regional information on water quality, drainage basins, pollution sources and loads,…

A generic hydrological model for a green roof drainage layer.

PubMed

Vesuviano, Gianni; Stovin, Virginia

2013-01-01

A rainfall simulator of length 5 m and width 1 m was used to supply constant intensity and largely spatially uniform water inflow events to 100 different configurations of commercially available green roof drainage layer and protection mat. The runoff from each inflow event was collected and sampled at one-second intervals. Time-series runoff responses were subsequently produced for each of the tested configurations, using the average response of three repeat tests. Runoff models, based on storage routing (dS/dt = I-Q) and a power-law relationship between storage and runoff (Q = kS(n)), and incorporating a delay parameter, were created. The parameters k, n and delay were optimized to best fit each of the runoff responses individually. The range and pattern of optimized parameter values was analysed with respect to roof and event configuration. An analysis was performed to determine the sensitivity of the shape of the runoff profile to changes in parameter values. There appears to be potential to consolidate values of n by roof slope and drainage component material.

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.

Mechanisms influencing changes in lake area in Alaskan boreal forest

USGS Publications Warehouse

Roach, Jennifer K.; Griffith, Brad; Verbyla, David; Jones, Jeremy B.

2011-01-01

During the past ∼50 years, the number and area of lakes have declined in several regions in boreal forests. However, there has been substantial finer-scale heterogeneity; some lakes decreased in area, some showed no trend, and others increased. The objective of this study was to identify the primary mechanisms underlying heterogeneous trends in closed-basin lake area. Eight lake characteristics (δ18O, electrical conductivity, surface : volume index, bank slope, floating mat width, peat depth, thaw depth at shoreline, and thaw depth at the forest boundary) were compared for 15 lake pairs in Alaskan boreal forest where one lake had decreased in area since ∼1950, and the other had not. Mean differences in characteristics between paired lakes were used to identify the most likely of nine mechanistic scenarios that combined three potential mechanisms for decreasing lake area (talik drainage, surface water evaporation, and terrestrialization) with three potential mechanisms for nondecreasing lake area (subpermafrost groundwater recharge through an open talik, stable permafrost, and thermokarst). A priori expectations of the direction of mean differences between decreasing and nondecreasing paired lakes were generated for each scenario. Decreasing lakes had significantly greater electrical conductivity, greater surface : volume indices, shallower bank slopes, wider floating mats, greater peat depths, and shallower thaw depths at the forest boundary. These results indicated that the most likely scenario was terrestrialization as the mechanism for lake area reduction combined with thermokarst as the mechanism for nondecreasing lake area. Terrestrialization and thermokarst may have been enhanced by recent warming which has both accelerated permafrost thawing and lengthened the growing season, thereby increasing plant growth, floating mat encroachment, transpiration rates, and the accumulation of organic matter in lake basins. The transition to peatlands associated

Preservation of labile organic matter in soils of drained thaw lakes in Northern Alaska

NASA Astrophysics Data System (ADS)

Mueller, Carsten W.; Rethemeyer, Janet; Kao-Kniffin, Jenny; Löppmann, Sebastian; Hinkel, Kenneth; Bockheim, James

2014-05-01

A large number of studies predict changing organic matter (OM) dynamics in arctic soils due to global warming. In contrast to rather slowly altering bulk soil properties, single soil organic matter (SOM) fractions can provide a more detailed picture of the dynamics of differently preserved SOM pools in climate sensitive arctic regions. By the study of the chemical composition of such distinctive SOM fractions using nuclear magnetic resonance spectroscopy (NMR) together with radiocarbon analyses it is possible to evaluate the stability of the major OM pools. Approximately 50-75% of Alaska's Arctic Coastal Plain is covered with thaw lakes and drained thaw lakes that follow a 5,000 yr cycle of development (between creation and final drainage), thus forming a natural soil chronosequence. The drained thaw lakes offer the possibility to study SOM dynamics affected by permafrost processes over millennial timescales. In April 2010 we sampled 16 soil cores (including the active and permanent layer) reaching from young drained lakes (0-50 years since drainage) to ancient drained lakes (3000-5500 years since drainage). Air dried soil samples from soil horizons of the active and permanent layer were subjected to density fractionation in order to differentiate particulate OM and mineral associated OM. The chemical composition of the SOM fractions was analyzed by 13C CPMAS NMR spectroscopy. For a soil core of a young and an ancient drained thaw lake basin we also analyzed the 14C content. For the studied soils we can show that up to over 25 kg OC per square meter are stored mostly as labile, easily degradable organic matter rich in carbohydrates. In contrast only 10 kg OC per square meter were sequestered as presumably more stable mineral associated OC dominated by aliphatic compounds. Comparable to soils of temperate regions, we found small POM (< 20 µm) occluded in aggregated soil structures which differed in the chemical composition from larger organic particles. This was

Benthic invertebrates of fixed sites in the western Lake Michigan drainages, Wisconsin and Michigan, 1993-95

USGS Publications Warehouse

Lenz, Bernard N.; Rheaume, S.J.

2000-01-01

This report describes the variability in family-level benthic-invertebrate population data and the reliability of the data as a water-quality indicator for 11 fixed surface-water sites in the Western Lake Michigan Drainages study area of the National Water-Quality Assessment Program. Benthic-invertebrate-community measures were computed for the following: number of individuals, Hilsenhoff’s Family-Level Biotic Index, number and percent EPT (Ephemeroptera, Plecoptera, and Tricoptera), Margalef’s Diversity Index, and mean tolerance value. Relations between these measures and environmental setting, habitat, and of chemical water quality are examined. Benthic-invertebrate communities varied greatly among fixed sites and within individual streams among multiple-reach and multiple-year sampling. The variations between multiple reaches and years were sometimes larger than those found between different fixed sites. Factors affecting benthic invertebrates included both habitat and chemical quality. Generally, fixed-site streams with the highest diversity, greatest number of benthic invertebrates, and those at which community measures indicated the best water quality also had the best habitat and chemical quality. Variations among reaches are most likely related to differences in habitat. Variations among years are most likely related to climatic changes, which create variations in flow and/or chemical quality. The variability in the data analyzed in this study shows how benthic invertebrates are affected by differences in both habitat and water quality, making them useful indicators of stream health; however, a single benthic-invertebrate sample alone cannot be relied upon to accurately describe water quality of the streams in this study. Benthic-invertebrate data contributed valuable information on the biological health of the 11 fixed sites when used as one of several data sources for assessing water quality.

Paleolimnology of Lake Ontario: AN Assessment of Glacial Meltwater Influx

NASA Astrophysics Data System (ADS)

Hladyniuk, R.; Longstaffe, F. J.

2010-12-01

The timing and extent of glacial meltwater outbursts from the Laurentide Ice Sheet (LIS) may provide insight into their potential role in initiating and/or sustaining the Younger Dryas (YD) cooling event. It has been previously proposed that meltwater from the LIS suppressed thermohaline circulation in the Atlantic Ocean, leading to an abrupt change in climate (Broecker et al. 1989). Several pathways for transport of glacial meltwater to the Atlantic Ocean have been suggested in the past, including eastern flow through the St. Lawrence River system and discharge into the Arctic Ocean via a northwestern outlet (Murton et al. 2010). Glacial meltwater contributions to Lake Ontario and its ancient equivalents during the last ~14,000 cal BP have been evaluated using the oxygen-isotope compositions of ostracode shells from three sediment cores in Lake Ontario. Glacial Lake Iroquois (~12,500 cal BP) δ18O values as low as -18‰ suggest significant contribution of glacial meltwater runoff from the LIS. This glacial sediment is characterized by occasional grains of sand and gravel. These ice-rafted particles indicate how far icebergs floated and suggest close proximity to the LIS. Early Lake Ontario sediment (~12,000 cal BP) exhibits thicker laminations, suggestive of increased winter ice cover and perhaps a colder climate, and is characterized by slightly lower δ18O values (-19.5‰). The end of glacial-dominated sedimentation at ~11,800 cal BP is demarcated by a significant increase in lakewater δ18O values (-12.0‰), reflecting mixing between regional precipitation in the watershed and upstream inflow into Lake Ontario. At ~10,800 cal BP, the δ18O value of Lake Ontario decreased to ~-15‰. This change reflects the main Algonquin highstand in Lake Huron, which flooded into Lake Ontario from both the Fenelon Falls and Port Huron outlets at this time. Shortly thereafter, the opening of the North Bay outlet and isostatic rebound at the Port Huron outlet limited

Using Kettle Lake Records to Date and Interpret Holocene Ash Deposition in Upper Cook Inlet, Anchorage, AK

NASA Astrophysics Data System (ADS)

Werner, A.; Kathan, K. M.; Kaufman, D. S.; Hancock, J. R.; Waythomas, C. F.; Wallace, K. L.

2004-12-01

Fourteen sediment cores recovered from three kettle lakes (Goose, Little Campbell and Lorraine) near Anchorage, AK were used to document and date Holocene volcanic ash deposition in the upper Cook Inlet area. Small lakes (<0.5 km2) with small (<1.5 km2), low relief (<50 m), and well-vegetated drainage areas were selected in order to minimize ash remobilization by mass wasting and fluvial processes. The resulting stratigraphic records are interpreted as primary terpha-fall stratigraphies. Relative to the surrounding lacustrine sediments, the ash layers exhibit low organic-matter content (as determined by loss-on-ignition, LOI), high magnetic susceptibility (MS), increased density (X-radiographs), and bubble-wall glass shards. Some ash layers are up to 1 cm thick (macrotephra) consisting of pure glass, some occur as light bands, while others (microtephra) can only be located using non-visual techniques (MS, LOI and X-radiography). The thinnest microtephras observed occur either as discrete (1 mm) layers or diffuse laminations composed of tephra mixed with ambient lake sediment. Forty-five AMS C-14 dates on terrestrial macro fossils were used to constrain sedimentation-rate models for the cores, and to assign absolute ages to ash units. Comparison of inferred tephra ages corroborates our intra and inter basin stratigraphic correlations (+/- 200 yrs) based on physical and MS stratigraphy. Ten out of 12 macrotephras can be confidently correlated among all three lakes, whereas, two of the prominent tephras occur in one basin but not in the others. This suggests subtle differences in ash plume extents or differences in tephra preservation between lakes. A total of 24 Holocene ash units (12 macro and 12 micro) have been recognized and dated in the Anchorage area, suggesting an ash-fall frequency of about 2.4/1000 yrs. By comparison, historical records suggest more frequent ash-fall events (120/1000 yrs). Our data indicate that, either the ash layers are not consistently

Extremely acid Permian lakes and ground waters in North America

USGS Publications Warehouse

Benison, K.C.; Goldstein, R.H.; Wopenka, B.; Burruss, R.C.; Pasteris, J.D.

1998-01-01

Evaporites hosted by red beds (red shales and sandstones), some 275-265 million years old, extend over a large area of the North American mid- continent. They were deposited in non-marine saline lakes, pans and mud- flats, settings that are typically assumed to have been alkaline. Here we use laser Raman microprobe analyses of fluid inclusions trapped in halites from these Permian deposits to argue for the existence of highly acidic (pH < 1) lakes and ground waters. These extremely acidic systems may have extended over an area of 200,000 km2. Modern analogues of such systems may be natural acid lake and groundwater systems (pH ~2-4) in southern Australia. Both the ancient and modern acid systems are characterized by closed drainage, arid climate, low acid-neutralizing capacity, and the oxidation of minerals such as pyrite to generate acidity. The discovery of widespread ancient acid lake and groundwater systems demands a re-evaluation of reconstructions of surface conditions of the past, and further investigations of the geochemistry and ecology of acid systems in general.

Numerical simulation of steady state three-dimensional groundwater flow near lakes

USGS Publications Warehouse

Winter, Thomas C.

1978-01-01

Numerical simulation of three-dimensional groundwater flow near lakes shows that the continuity of the boundary encompassing the local groundwater flow system associated with a lake is the key to understanding the interaction of a lake with the groundwater system. The continuity of the boundary can be determined by the presence of a stagnation zone coinciding with the side of the lake nearest the downgradient side of the groundwater system. For most settings modeled in this study the stagnation zone underlies the lakeshore, and it generally follows its curvature. The length of the stagnation zone is controlled by the geometry of the lake's drainage basin divide on the side of the lake nearest the downgradient side of the groundwater system. In the case of lakes that lose water to the groundwater system, three-dimensional modeling also allows for estimating the area of lake bed through which outseepage takes place. Analysis of the effects of size and lateral and vertical distribution of aquifers within the groundwater system on the outseepage from lakes shows that the position of the center point of the aquifer relative to the littoral zone on the side of the lake nearest the downgradient side of the groundwater system is a critical factor. If the center point is downslope from this part of the littoral zone, the local flow system boundary tends to be weak or outseepage occurs. If the center point is upslope from this littoral zone, the stagnation zone tends to be stronger (to have a higher head in relation to lake level), and outseepage is unlikely to occur.

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

Climate simulation and flood risk analysis for 2008-40 for Devils Lake, North Dakota

USGS Publications Warehouse

Vecchia, Aldo V.

2008-01-01

Devils Lake and Stump Lake in northeastern North Dakota receive surface runoff from a 3,810-square-mile drainage basin, and evaporation provides the only major water loss unless the lakes are above their natural spill elevation to the Sheyenne River. In September 2007, flow from Devils Lake to Stump Lake had filled Stump Lake and the two lakes consisted of essentially one water body with an elevation of 1,447.1 feet, about 3 feet below the existing base flood elevation (1,450 feet) and about 12 feet below the natural outlet elevation to the Sheyenne River (1,459 feet).Devils Lake could continue to rise, causing extensive additional flood damages in the basin and, in the event of an uncontrolled natural spill, downstream in the Red River of the North Basin. This report describes the results of a study conducted by the U.S. Geological Survey, in cooperation with the Federal Emergency Management Agency, to evaluate future flood risk for Devils Lake and provide information for developing updated flood-insurance rate maps and planning flood-mitigation activities such as raising levees or roads.In about 1980, a large, abrupt, and highly significant increase in precipitation occurred in the Devils Lake Basin and elsewhere in the Northern Great Plains, and wetter-than-normal conditions have persisted through the present (2007). Although future precipitation is impossible to predict, paleoclimatic evidence and recent research on climate dynamics indicate the current wet conditions are not likely to end anytime soon. For example, there is about a 72-percent chance wet conditions will last at least 10 more years and about a 37-percent chance wet conditions will last at least 30 more years.A stochastic simulation model for Devils Lake and Stump Lake developed in a previous study was updated and used to generate 10,000 potential future realizations, or traces, of precipitation, evaporation, inflow, and lake levels given existing conditions on September 30, 2007, and randomly

Water-Balance Model to Simulate Historical Lake Levels for Lake Merced, California

NASA Astrophysics Data System (ADS)

Maley, M. P.; Onsoy, S.; Debroux, J.; Eagon, B.

2009-12-01

Lake Merced is a freshwater lake located in southwestern San Francisco, California. In the late 1980s and early 1990s, an extended, severe drought impacted the area that resulted in significant declines in Lake Merced lake levels that raised concerns about the long-term health of the lake. In response to these concerns, the Lake Merced Water Level Restoration Project was developed to evaluate an engineered solution to increase and maintain Lake Merced lake levels. The Lake Merced Lake-Level Model was developed to support the conceptual engineering design to restore lake levels. It is a spreadsheet-based water-balance model that performs monthly water-balance calculations based on the hydrological conceptual model. The model independently calculates each water-balance component based on available climate and hydrological data. The model objective was to develop a practical, rule-based approach for the water balance and to calibrate the model results to measured lake levels. The advantage of a rule-based approach is that once the rules are defined, they enhance the ability to then adapt the model for use in future-case simulations. The model was calibrated to historical lake levels over a 70-year period from 1939 to 2009. Calibrating the model over this long historical range tested the model over a variety of hydrological conditions including wet, normal and dry precipitation years, flood events, and periods of high and low lake levels. The historical lake level range was over 16 feet. The model calibration of historical to simulated lake levels had a residual mean of 0.02 feet and an absolute residual mean of 0.42 feet. More importantly, the model demonstrated the ability to simulate both long-term and short-term trends with a strong correlation of the magnitude for both annual and seasonal fluctuations in lake levels. The calibration results demonstrate an improved conceptual understanding of the key hydrological factors that control lake levels, reduce uncertainty

Late Quaternary megafloods from Glacial Lake Atna, Southcentral Alaska, U.S.A.

NASA Astrophysics Data System (ADS)

Wiedmer, Michael; Montgomery, David R.; Gillespie, Alan R.; Greenberg, Harvey

2010-05-01

Geomorphic, stratigraphic, geotechnical, and biogeographic evidence indicate that failure of a Pleistocene ice dam between 15.5 and 26 ka generated a megaflood from Glacial Lake Atna down the Matanuska Valley. While it has long been recognized that Lake Atna occupied ≥ 9000 km 2 of south-central Alaska's Copper River Basin, little attention has focused on the lake's discharge locations and behaviors. Digital elevation model and geomorphic analyses suggest that progressive lowering of the lake level by decanting over spillways exposed during glacial retreat led to sequential discharges down the Matanuska, Susitna, Tok, and Copper river valleys. Lake Atna's size, ˜ 50 ka duration, and sequential connection to four major drainages likely made it a regionally important late Pleistocene freshwater refugium. We estimate a catastrophic Matanuska megaflood would have released 500-1400 km 3 at a maximum rate of ≥ 3 × 10 6 m 3 s - 1 . Volumes for the other outlets ranged from 200 to 2600 km 3 and estimated maximum discharges ranged from 0.8 to 11.3 × 10 6 m 3 s - 1 , making Lake Atna a serial generator of some of the largest known freshwater megafloods.

Genetic structure of Columbia River redband trout populations in the Kootenai River drainage, Montana, revealed by microsatellite and allozyme loci

USGS Publications Warehouse

Knudsen, K.-L.; Muhlfeld, C.C.; Sage, G.K.; Leary, R.F.

2002-01-01

We describe the genetic divergence among 10 populations of redband trout Oncorhynchus mykiss gairdneri from the upper Columbia River drainage. Resident redband trout from two watersheds in the Kootenai River drainage and hatchery stocks of migratory Kamloops redband trout from Kootenay Lake, British Columbia, were analyzed using allele frequency data from microsatellite and allozyme loci. The Kamloops populations have significantly different allele frequencies from those of the Kootenai River drainage. Of the total genetic variation detected in the resident redband trout, 40.7% (microsatellites) and 15.5% (allozymes) were due to differences between populations from the two Kootenai River watersheds. The divergence among populations within each watershed, however, was less than 3.5% with both techniques. Our data indicate that watershed-specific broodstocks of redband trout are needed by fisheries managers for reintroduction or the supplementation of populations at risk of extinction.

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.

Reducing nitrate loss in tile drainage water with cover crops and water-table management systems.

PubMed

Drury, C F; Tan, C S; Welacky, T W; Reynolds, W D; Zhang, T Q; Oloya, T O; McLaughlin, N B; Gaynor, J D

2014-03-01

Nitrate lost from agricultural soils is an economic cost to producers, an environmental concern when it enters rivers and lakes, and a health risk when it enters wells and aquifers used for drinking water. Planting a winter wheat cover crop (CC) and/or use of controlled tile drainage-subirrigation (CDS) may reduce losses of nitrate (NO) relative to no cover crop (NCC) and/or traditional unrestricted tile drainage (UTD). A 6-yr (1999-2005) corn-soybean study was conducted to determine the effectiveness of CC+CDS, CC+UTD, NCC+CDS, and NCC+UTD treatments for reducing NO loss. Flow volume and NO concentration in surface runoff and tile drainage were measured continuously, and CC reduced the 5-yr flow-weighted mean (FWM) NO concentration in tile drainage water by 21 to 38% and cumulative NO loss by 14 to 16% relative to NCC. Controlled tile drainage-subirrigation reduced FWM NO concentration by 15 to 33% and cumulative NO loss by 38 to 39% relative to UTD. When CC and CDS were combined, 5-yr cumulative FWM NO concentrations and loss in tile drainage were decreased by 47% (from 9.45 to 4.99 mg N L and from 102 to 53.6 kg N ha) relative to NCC+UTD. The reductions in runoff and concomitant increases in tile drainage under CC occurred primarily because of increases in near-surface soil hydraulic conductivity. Cover crops increased corn grain yields by 4 to 7% in 2004 increased 3-yr average soybean yields by 8 to 15%, whereas CDS did not affect corn or soybean yields over the 6 yr. The combined use of a cover crop and water-table management system was highly effective for reducing NO loss from cool, humid agricultural soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Nitrate concentration-drainage flow (C-Q) relationship for a drained agricultural field in Eastern North Carolina Plain

NASA Astrophysics Data System (ADS)

Liu, W.; Youssef, M.; Birgand, F.; Chescheir, G. M.; Maxwell, B.; Tian, S.

2017-12-01

Agricultural drainage is a practice used to artificially enhance drainage characteristics of naturally poorly drained soils via subsurface drain tubing or open-ditch systems. Approximately 25% of the U.S. agricultural land requires improved drainage for economic crop production. However, drainage increases the transport of dissolved agricultural chemicals, particularly nitrates to downstream surface waters. Nutrient export from artificially drained agricultural landscapes has been identified as the leading source of elevated nutrient levels in major surface water bodies in the U.S. Controlled drainage has long been practiced to reduce nitrogen export from agricultural fields to downstream receiving waters. It has been hypothesized that controlled drainage reduces nitrogen losses by promoting denitrification, reducing drainage outflow from the field, and increasing plant uptake. The documented performance of the practice was widely variable as it depends on several site-specific factors. The goal of this research was to utilize high frequency measurements to investigate the effect of agricultural drainage and related management practices on nitrate fate and transport for an artificially drained agricultural field in eastern North Carolina. We deployed a field spectrophotometer to measure nitrate concentration every 45 minutes and measured drainage flow rate using a V-notch weir every 15 minutes. Furthermore, we measured groundwater level, precipitation, irrigation amount, temperature to characterize antecedent conditions for each event. Nitrate concentration-drainage flow (C-Q) relationships generated from the high frequency measurements illustrated anti-clockwise hysteresis loops and nitrate flushing mechanism in response to most precipitation and irrigation events. Statistical evaluation will be carried out for the C-Q relationships. The results of our analysis, combined with numerical modeling, will provide a better understanding of hydrological and

Application of digital image processing techniques and information systems to water quality monitoring of Lake Tahoe

NASA Technical Reports Server (NTRS)

Smith, A. Y.; Blackwell, R. J.

1981-01-01

The Tahoe basin occupies over 500 square miles of territory located in a graben straddling the boundary between California and Nevada. Lake Tahoe contains 126 million acre-feet of water. Since the 1950's the basin has experienced an ever increasing demand for land development at the expense of the natural watershed. Discharge of sediment to the lake has greatly increased owing to accelerated human interference, and alterations to the natural drainage patterns are evident in some areas. In connection with an investigation of the utility of a comprehensive system that takes into account the causes as well as the effects of lake eutrophication, it has been attempted to construct an integrated and workable data base, comprised of currently available data sources for the Lake Tahoe region. Attention is given to the image based information system (IBIS), the construction of the Lake Tahoe basin data base, and the application of the IBIS concept to the Lake Tahoe basin.

Glacier Instability, Rapid Glacier Lake Growth and Related Hazards at Belvedere Glacier, Macugnaga, Italy

NASA Astrophysics Data System (ADS)

Huggel, C.; Kaeaeb, A.; Haeberli, W.; Mortara, G.; Chiarle, M.; Epifani, F.

2002-12-01

Starting in summer 2000, Belvedere Glacier, near Macugnaga, Italian Alps, developed an extraordinary change in flow, geometry and surface appearance. A surge-type flow acceleration started in the lower parts of the Monte-Rosa east face, leading to strong crevassing and deformation of Belvedere Glacier, accompanied by bulging of its orographic right margin. In September 2001, a small supraglacial lake developed on the glacier. High water pressure and accelerated movement lasted into winter 2001/2002. The ice, in places, started to override moraines from the Little Ice Age. In late spring and early summer 2002, the supraglacial lake grew at extraordinary rates reaching a maximum area of more than 150'000 m2 by end of June. The evolution of such a large supraglacial lake, a rather unique feature in the Alps, was probably enabled by changes in the subglacial drainage system in the course of the surge-like developments with high water pressure in the glacier. At the end of June, an enhanced growth of the lake level with a rise of about 1 m per day was observed such that the supraglacial lake became a urgent hazard problem for the community of Macugnaga. Emergency measures had to be taken by the Italian Civil Protection. The authors thereby acted as the official expert advisers. Temporal evacuations were ordered and a permanent monitoring and alarm system was installed. Pumps with a maximum output of 1 m3/s were brought to the lake. Bathymetric studies yielded a maximum lake depth of 55 m and a volume of 3.3 millions of cubic meters of water. Aerial photography of 1995, 1999, September 2001 and October 2001 was used to calculate ice flow velocities and changes in surface altitude. Compared to the period of 1995 to 1999, the flow accelerated by about five times in 2001 (max. speeds up to 200 m/yr). Surface uplift measured was about 10-15 m/yr. The results of the photogrammetric studies were used to evaluate different possible lake-outburst scenarios, in particular

Hydrograph Predictions of Glacial Lake Outburst Floods From an Ice-Dammed Lake

NASA Astrophysics Data System (ADS)

McCoy, S. W.; Jacquet, J.; McGrath, D.; Koschitzki, R.; Okuinghttons, J.

2017-12-01

Understanding the time evolution of glacial lake outburst floods (GLOFs), and ultimately predicting peak discharge, is crucial to mitigating the impacts of GLOFs on downstream communities and understanding concomitant surface change. The dearth of in situ measurements taken during GLOFs has left many GLOF models currently in use untested. Here we present a dataset of 13 GLOFs from Lago Cachet Dos, Aysen Region, Chile in which we detail measurements of key environmental variables (total volume drained, lake temperature, and lake inflow rate) and high temporal resolution discharge measurements at the source lake, in addition to well-constrained ice thickness and bedrock topography. Using this dataset we test two common empirical equations as well as the physically-based model of Spring-Hutter-Clarke. We find that the commonly used empirical relationships based solely on a dataset of lake volume drained fail to predict the large variability in observed peak discharges from Lago Cachet Dos. This disagreement is likely because these equations do not consider additional environmental variables that we show also control peak discharge, primarily, lake water temperature and the rate of meltwater inflow to the source lake. We find that the Spring-Hutter-Clarke model can accurately simulate the exponentially rising hydrographs that are characteristic of ice-dammed GLOFs, as well as the order of magnitude variation in peak discharge between events if the hydraulic roughness parameter is allowed to be a free fitting parameter. However, the Spring-Hutter-Clarke model over predicts peak discharge in all cases by 10 to 35%. The systematic over prediction of peak discharge by the model is related to its abrupt flood termination that misses the observed steep falling limb of the flood hydrograph. Although satisfactory model fits are produced, the range in hydraulic roughness required to obtain these fits across all events was large, which suggests that current models do not

Composite fibrous glaucoma drainage implant

NASA Astrophysics Data System (ADS)

Klapstova, A.; Horakova, J.; Shynkarenko, A.; Lukas, D.

2017-10-01

Glaucoma is a frequent reason of loss vision. It is usually caused by increased intraocular pressure leading to damage of optic nerve head. This work deals with the development of fibrous structure suitable for glaucoma drainage implants (GDI). Commercially produced metallic glaucoma implants are very effective in lowering intraocular pressure. However, these implants may cause adverse events such as damage to adjacent tissue, fibrosis, hypotony or many others [1]. The aim of this study is to reduce undesirable properties of currently produced drains and improve their properties by creating of the composite fibrous drain for achieve a normal intraocular pressure. Two types of electrospinning technologies were used for the production of very small tubular implants. First type was focused for production of outer part of tubular drain and the second type of electrospinning method made the inner part of shape follows the connections of both parts. Complete implant had a special properties suitable for drainage of fluid. Morphological parameters, liquid transport tests and in-vitro cell adhesion tests were detected.