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Sample records for lake baikal

  1. Upwellings in Lake Baikal

    NASA Astrophysics Data System (ADS)

    Shimaraev, M. N.; Troitskaya, E. S.; Blinov, V. V.; Ivanov, V. G.; Gnatovskii, R. Yu.

    2012-02-01

    Based on shipboard and satellite observations, the characteristics of upwelling in Lake Baikal in the period of direct temperature stratification have been determined for the first time. Coastal upwellings appear annually under the effect of run-down and alongshore winds and are traced along the coast to a distance of up to 60-100 km and up to 250 km in North Baikal. Analogous to the way it occurs in seas, water rises from the depths of 100-200 m (350 m as a maximum) at the velocity of 0.1 × 10-2-6.5 × 10-2 cm/s. Divergence in the field of intràbasin cyclonic macrovortices produces upwelling in the Baikal pelagic zone and downwelling in the vicinity of shores; this lasts from 7 to 88 days and covers the depth interval of 80-300 m in August and up to 400-800 m in early-mid November. The area of upwellings occupies up to 20-60% of the separate basins of the lake. Vertical circulation of water in the field of pelagic upwellings leads to intensification of coastal currents and to formation of the thermobar with a heat inert zone in the central part of the lake in November, and this thermobar is not observed in other lakes, at that.

  2. Thermal springs in Lake Baikal

    SciTech Connect

    Shanks, W.C. III; Callender, E. )

    1992-06-01

    Pore waters extracted from sediment cores were analyzed for their oxygen and hydrogen isotopic compositions and major ion chemistry to determine the source of water from a vent area for diffuse lake-bottom thermal springs or seeps in Frolikha Bay, northeastern Lake Baikal. The {delta}{sup 18}O values of pore waters range from {minus}15.2{per thousand} to {minus}16.7{per thousand}, and {delta}D values range from {minus}119{per thousand} to {minus}126{per thousand} (both isotopes determined relative to standard mean ocean water (SMOW)). Bottom water in Lake Baikal has a {delta}{sup 18}O value of {minus}5.6{per thousand} and a {delta}D values of {minus}120{per thousand}. Pore waters in the vent area are significantly enriched in Mg, K, Ca, and especially Na and have the lowest {delta}D and {delta}{sup 18}O values; these pore waters are isotopically and chemically distinct from pore waters in other, more typical parts of the lake. The pore-water isotopic data fall on a local meteoric water line, and covariations in water isotopes and chemistry are not consistent with evaporation or hydrothermal water-rock interaction. The thermal springs represent discharging meteoric waters that have been gently heated during subsurface circulation and are largely unaltered isotopically. Chemical variations are most likely due to dissolution of subsurface evaporites.

  3. Search for ancient microorganisms in Lake Baikal

    SciTech Connect

    Hunter-Cevera, Jennie C.; Repin, Vladimir E.; Torok, Tamas

    2000-06-14

    Lake Baikal in Russia, the world's oldest and deepest continental lake lies in south central Siberia, near the border to Mongolia. The lake is 1,643 m deep and has an area of about 46,000 km2. It holds one-fifth of all the terrestrial fresh water on Earth. Lake Baikal occupies the deepest portion of the Baikal Rift Zone. It was formed some 30-45 million years ago. The isolated Lake Baikal ecosystem represents a unique niche in nature based on its historical formation. The microbial diversity present in this environment has not yet been fully harvested or examined for products and processes of commercial interest and value. Thus, the collection of water, soil, and sub-bottom sediment samples was decided to characterize the microbial diversity of the isolated strains and to screen the isolates for their biotechnological value.

  4. Biogeochemical phosphorus mass balance for Lake Baikal, southeastern Siberia, Russia

    USGS Publications Warehouse

    Callender, E.; Granina, L.

    1997-01-01

    Extensive data for Lake Baikal have been synthesized into a geochemical mass balance for phosphorus (P). Some of the P budget and internal cycling terms for Baikal have been compared to similar terms for oligotrophic Lake Superior, mesotrophic Lake Michigan and the Baltic Sea, and the Ocean. Lake Baikal has a large external source of fluvial P compared to the Laurentian upper Great Lakes and the Ocean. The major tributary to Lake Baikal has experienced substantial increases in organic P loading during the past 25 years. This, coupled with potential P inputs from possible phosphorite mining, may threaten Baikal's oligotrophic status in the future. Water-column remineralization of particulate organic P is substantially greater in Lake Baikal than in the Laurentian Great Lakes. This is probably due to the great water depths of Lake Baikal. There is a gradient in P burial efficiency, with very high values (80%) for Lake Baikal and Lake Superior, lower values (50%) for Lake Michigan and the Baltic Sea, and a low value (13%) for the Ocean. The accumulation rate of P in Lake Baikal sediments is somewhat greater than that in the Laurentian upper Great Lakes and the Baltic Sea, and much greater than in the Ocean. Benthic regeneration rates are surprisingly similar for large lacustrine and marine environments and supply less than 10% of the P utilized for primary production in these aquatic environments.

  5. Lake Baikal deepwater renewal mystery solved

    NASA Astrophysics Data System (ADS)

    Schmid, Martin; Budnev, Nikolay M.; Granin, Nick G.; Sturm, Michael; Schurter, Michael; Wüest, Alfred

    2008-05-01

    Deepwater renewal by intrusions and turbulent diffusion in Lake Baikal is very effective despite the enormous depth of up to 1642 m and the permanently stable stratification below ~300 m depth. Temperature time series recorded at the bottom of a mooring installed since March 2000 in the South Basin of the lake indicate recurrent freshwater intrusions with volumes of 50 to 100 km3, about one order of magnitude larger than previously observed intrusions. Numerous mechanisms have been proposed to explain the advective deep water renewal. Here we present for the first time direct observations which prove that they are caused by coastal downwelling and subsequent thermobaric instability along the steep lake shores. Understanding these mechanisms is an important prerequisite for studying biogeochemical cycles, for predicting the effects of climate change on this unique ecosystem and for evaluating the local climate history from the extraordinary sedimentary record of Lake Baikal.

  6. Controlling Deep Water Renewal in Lake Baikal

    NASA Astrophysics Data System (ADS)

    Tsimitri, C.; Schmid, M.; Wuest, A.

    2012-12-01

    Lake Baikal is the most voluminous and deepest fresh water body on earth. Despite its great depth, about 1.6 Km and its permanent stratification below ~300 m, the lake supports a remarkable biodiversity with a major deep-water fauna composed almost entirely of endemic species. A key element contributing to this unique ecosystem is the high oxygen concentration observed throughout the water column. This extraordinary feature is sustained by regular deep water renewal. The South Basin of the lake has been monitored with moored thermistors for more than a decade. By analyzing the obtained data series we investigate the importance of coastal downwelling and of the subsequent thermobaric instability to the renewal. We study how the local wind field, the ice coverage and the stratification of the upper water layers can control the deep water state. Understanding the deep water renewal mechanism is an important prerequisite for studying biochemical cycles, for predicting the effects of climate change on this unique ecosystem and for evaluating the local climate history from the extraordinary sedimentary record of Lake Baikal.

  7. Active seepage and water infiltration in Lake Baikal sediments: new thermal data from TTR-Baikal 2014 (Class@Baikal)

    NASA Astrophysics Data System (ADS)

    Poort, Jeffrey; Khlystov, Oleg M.; Akhmanov, Grigorii G.; Khabuev, Andrei V.; Belousov, Oleg V.

    2015-04-01

    New thermal data from the sediments of Lake Baikal were collected in July 2014 during the first Training-Through-Research cruise on Lake Baikal (Class@Baikal) organized by MGU and LIN. TTR-Baikal is a comprehensive multidisciplinary program to train students on the field on pertinent scientific topics. The cruise program focused on seafloor sampling, acoustic investigations and heat flow measurements of gas seeps, flares, mud volcanoes, slumps and debris flows, canyons and channels in the coastal proximity. The thermal data were acquired using autonomous temperature sensors on a 3 meter long gravity corer that allowed analysis at the same spot of sediments, pore fluids, hydrates and microbiology. A total of eight thermal measurements were performed in five structures located on the lake floor of the Central Baikal Basin at 333-1530 meter water depths: 3 mud volcanoes (Novosibirsk, Unshuy and Krest), 1 seep site (Seep 13), and one fault outcrop in the Selenga transfer zone. All studied structures show signals of active seepage, water infiltration and/or hydrate dynamics. The strongest thermal gradient has been measured in Seep 13, suggesting a strong upflow of warm fluids similar to the Gorevoy Utes seep. At the three mud volcanoes, hydrate presence have been evidenced and both enhanced and reduced thermal gradients have been observed. This is similar to the hydrate-bearing K-2 mud volcano in Baikal (Poort et al., 2012). A strongly reduced thermal gradient was observed in the Krest mud volcano where the presence of oxidized channels at 30-40 cm under the sediment surface indicate an infiltration of cold lake water. The water infiltration process at hydrate bearing seep sites will be discussed and compared with other seep areas in the world.

  8. Authigenic Molybdenum Isotopes Record Lake Baikal in the Past

    NASA Astrophysics Data System (ADS)

    Yu, E.; Liu, H.; Lee, D.

    2013-12-01

    Authigenic molybdenum isotope signatures in marine sediments reflect the mechanisms of deposits under both oxic and reducing conditions. The studies are mainly focusing on marine environment, and the application on lake record is rare. A three-meters long gravity core (GC-99; 52°05'23'N, 105°50'24'E; water depth 201m) from Lake Baikal is studied for Mo isotopes and concentration. The result is using to examine the sources of material or/and the changes in conditions of Lake Baikal with climate changes. To approach on extracting Mo isotope signal directly related to lake water, a sequential leaching technique to extract the Mo isotopes coating on the Fe-Mn oxides and a robust chromatography technique to purify molybdenum isotopes is modified and used for all lake sediment samples. Then, Mo isotope composition is measured by applying double spike method with Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS). According to the Mo concentration and its isotope composition δ98/95Mo relative to NIST-SRM-3134, the results imply Lake Baikal stayed oxic condition over the last 24 ka. Moreover, the sediment core GC-99 from Lake Baikal imply two stages fluctuations of the lake environment separated at core depth of 100cm (around 12ka); and the shifting of δ98/95Mo isotope composition shows that the lake during interglacial period was more oxic than the last glacial period due to absence of ice cover.

  9. Chlorinated hydrocarbon residues in Baikal seal (Phoca sibirica) from Lake Baikal: Levels, patterns, and metabolism

    SciTech Connect

    Nakata, H.; Tanabe, S.; Tatsukawa, R.; Amano, M.; Miyazaki, N.; Petrov, A.

    1995-12-31

    Contamination of chlorinated hydrocarbons such as DDTs (DDT and its metabolites), PCBs (polychlorinated biphenyls), CHLs (chlordane compounds) and HCHs (hexachlorocyclohexanes) was assessed in the blubber of Baikal seal (Phoca sibirica) and their fish diet collected from Lake Baikal in 1992. Higher concentrations of DDTs and PCBs were detected, ranging from 4.9 to 160 {micro}g/g and 3.5 to 64 {micro}g/g on a lipid weight basis, respectively, whereas levels of CHLs and HCHs were approximately one or three orders of magnitude lower than those of DDTs and PCBs. The average of DDTs concentrations in adult male Baikal seals were about an order of magnitude higher than those reported for seals in the North Sea around UK and comparable to grey seal in the Baltic Sea, indicating that Baikal seals are categorized in a highly contaminated group. A positive age dependent accumulation of DDTs, PCBs and CHLs was found in male, while a steady-state was observed in female which attributes to the reproductive transfer, mainly lactation, of these chemicals. On the basis of contaminant burdens in adult seals, it was estimated that adult females transfer about 19% and 14% of their DDT and PCB body burdens to their pups during a reproductive process. Based on the data from isomer specific analysis of PCBs, it can be suggested that Baikal seals have higher capacity to metabolize congeners with vicinal H-atoms in meta, para positions than those of marine mammals.

  10. Elements of the iron and manganese cycles in Lake Baikal

    USGS Publications Warehouse

    Granina, L.Z.; Callender, E.

    2007-01-01

    Using data obtained in recent years, we considered the external mass balance and characteristics of internal iron and manganese cycles in Lake Baikal (biological uptake, remineralization, sedimentary and diffusive fluxes, accumulation in sediments, time of renewal, etc.). Some previous results and common concepts were critically reevaluated. ?? Pleiades Publishing, Ltd. 2007.

  11. Functional convergence among pelagic sculpins of Lake Baikal and deepwater ciscoes of the Great Lakes

    USGS Publications Warehouse

    Eshenroder, Randy L.; Sideleva, Valentina G.; Todd, Thomas N.

    1999-01-01

    The vast, well-oxygenated hypolimnia of Lake Baikal and the Great Lakes were both dominated by endemic planktivorous fishes. These dominants, two species of sculpins (Comephorus, Comephoridae) in Lake Baikal and six species of deepwater ciscoes (Coregonus, Salmonidae) in the Great Lakes, although distant taxonomically, have morphologies suggesting a surprising degree of functional convergence. Here it is proposed that the same two buoyancy-regulation strategies observed in Baikal sculpins also arose in the deepwater ciscoes of the Great Lakes. One strategy favors hydrostatic lift (generated by low specific gravity) and is characterized by fatter, larger-bodied fish with smaller paired fins; the second strategy favors hydrodynamic lift (generated by swimming) and is characterized by leaner, smaller-bodied fish with larger paired fins. Both types likely evolved to feed on a single species of ecologically analogous, vertically migrating macrozooplankter: Macrohectopus branickii in Lake Baikal and Mysis relicta in the Great Lakes. It is suggested that Coregonus did not diversify and proliferate in Lake Baikal as they did in the Great Lakes because by the time Coregonus colonized Lake Baikal, pelagic sculpins were already dominant.

  12. The Class@Baikal project: studying recent tectonics, sedimentology and geochemistry on Lake Baikal

    NASA Astrophysics Data System (ADS)

    Akhmanov, Grigorii; Khlystov, Oleg; Mazzini, Adriano; Poort, Jeffrey; Giliazetdinova, Dina

    2016-04-01

    The Class@Baikal project - onboard training of the marine science students on the Baikal Lake - is successfully running for the second year following and carrying further the traditions laid out by the legendary UNESCO Training-through-Research (Floating University) Programme. Main areas studied during two Class@Baikal cruises are: "Bolshoy Mud Volcano" is located at the southern deep of the lake. Dense profiler lines grid has been acquired during the Class@Baikal-2015 expedition. A sedimentary core with mud breccia and massive gas hydrates was collected from the southern crater confirming its active status. "Krasny Yar seeps" are located within outer delta of the Selenga River. Side-scan sonar, profiler and multibeam data show that there is a well-expressed amphitheatre-shaped slump scour nearby. Slumped sediments and associated amphitheater scour were mapped. Data indicated that the seabed scour has steep walls. Propagation of the slumped sediments had been stopped by a seabed ridge of unknown origin. At the north the ridge is breached and the slumped material funnels out through a narrow opening spreading down the slope by gravity flows. "Novosibirsk" and "St.Petersburg mud volcanoes" are located along a fault. The mud volcanoes are located partially along its hanging wall and partially along its foot wall. Side-scan sonar and profiler data acquired during Class@Baikal-2015 expedition show that both mud volcanoes demonstrate evidence of a vertical material transport within feeder channels, which developed on both sides of the fault. The fault seems to be separating the mud volcano area into clusters. It is proposed that initially the fault did not have vertical offset but nevertheless initiated mud volcanic activity. The early mud volcanoes had usual symmetric morphology. The vertical offset of the fault took place later and this resulted in formation of the blocky asymmetry of the structures. "Khuray deep-water depositional system" study has begun in 2014 when

  13. Space Radar Image of Baikal Lake, Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This is an X-band black-and-white image of the forests east of the Baikal Forest in the Jablonowy Mountains of Russia. The image is centered at 52.5 degrees north latitude and 116 degrees east longitude near the mining town of Bukatschatscha. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar aboard the space shuttle Endeavour on October 4, 1994, during the second flight of the spaceborne radar. This area is part of an international research project known as the Taiga Aerospace Investigation using Geographic Information System Applications.

  14. Pleistocene sediments of Lake Baikal: Lithology and stratigraphic correlation

    NASA Astrophysics Data System (ADS)

    Akulov, N. I.; Mashchuk, I. M.; Akulova, V. V.

    2015-01-01

    The Cenozoic sediments of Lake Baikal penetrated by boreholes and investigated by the manned submersible Pisces, as well as coeval deposits cropping out in beach scarps, recovered by mine workings, and drilled in the coastal zone were the object of this investigation. The main attention was paid to Pleistocene bottom sediments penetrated by Borehole BDP-99-2. The investigations included the detailed analysis of the lithology (grain-size composition, immersion mineralogy of light and heavy fractions, X-ray structural analysis of clayey fraction) and palynological assemblages to specify facies features of Cenozoic sediments, correlate all their known stratigraphic units constituting the sedimentary section of the lake with their analogs in the onshore part of the Baikal rift zone, and compile the composite Cenozoic section. The following features of these sediments are noted: (1) as a whole, Pleistocene sediments are characterized by the hydromica-smectite composition of their clayey fraction with an insignificant share of kaoline; (2) the heavy fraction is dominated by the terrigenous epidote-amphibole association poorly resistant to weathering; (3) Pleistocene sediments of the lake contain siderite, vivianite, pyrite, and goethite concretions and micrometeorites, in addition to well-known ferromanganese nodules; (4) the presence of relict palynomorphs in Pleistocene sediments of Baikal is determined by their erosion from Miocene and Pliocene cavernous clays cropping out on underwater slopes of the Posol'skaya Bank and subsequent reburial along with Pleistocene palynological assemblages.

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

    USGS Publications Warehouse

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

    1998-01-01

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

  16. An interesting natural phenomenon - giant rings on Lake Baikal ice

    NASA Astrophysics Data System (ADS)

    Kouraev, Alexei; Shimaraev, Michail; Remy, Frederique; Ivanov, Andrei; Golubov, Boris

    2010-05-01

    Starting from May 2009 scientific community and large public have been puzzled by the formation of giant rings on Baikal ice. These rings (diameter 5-7 km, thickness of dark layer - 1 - 1.8 km) have almost perfect circular shape what makes them so interesting and attractive not only to scientists, but also for large public. . The rings have been observed since 1999 by various satellites and sensors (AVHRR, MODIS, Landsat, SPOT) as early as 1999 but probably also in 1984 and 1994 (Shuttle missions). These rings are usually well observed in April, when snow cover is thin or absent. Rings have been observed in the southern tip of the lake (2009), and in three places in the central part: near Krestovskiy cape (1999, 2003, 2005 and 2008), near Turka (2008), and near Cape Nizhnee Izgolovye (2009). All these places are located in the region of steep bottom topography, over depths of more than 500 m. According to in situ measurements done by the Limnological Institute in Irkutsk in 2009, ice thickness is about 70 cm in the center and on the outside of the ring, and 40 cm in the ring itself. It is known that the Baikal lake has important hydrothermal activity, and there are numerous observations of gas (methane etc) seepage from its 7 km-thick layer of bottom sediments. Local-scale absence of ice cover (steamthroughs or "propariny") is typical for some places in Lake Baikal. They result from gas emissions (associated with rise of warm water), near capes and straits (due to better vertical mixing), thermal sources, outlets of large rivers. Often they are observed near Capes Big and Small Kadil'niy, and in the Olkhonskiye vorota strait. However they size ranges from just a half a meter to several hundreds of meters (but not several kilometers) and this could not be an explanation for the formation of giant rings. We present several existing hypotheses of the origin of these rings including gas emission, heat flux, cyclonic subsurface currents and mega-bubble formation due to

  17. Geochemical mass balances of major elements in Lake Baikal

    USGS Publications Warehouse

    Callender, E.; Granina, L.

    1997-01-01

    Major element mass balances for Lake Baikal are calculated with mostly previously published data for soluble fluxes and new, unpublished data for riverine suspended particulate matter chemistry. Physical transport seems to be the most important riverine process. The elements Ca, Mg, and Na seem to be very mobile in the weathering mantle and K and Si seem to be relatively mobile. A comparison of elemental input-output budgets and mass accumulation rates (MAR) in bottom sediments shows that most major elements, except Ca, Si, and Mn, have comparable riverine particulate matter fluxes and MARs. The addition of wet atmospheric deposition fluxes results in an excess of Ca, Mg, and Na entering the lake. The additive effect of these excess inputs during a 40-year period amounts to undetectable concentration increases in the water column. If erosion of weathered bedrock is the source of most dissolved and all particulate matter transported to the lake, theoretical elemental fluxes can be calculated with Al as the conservative element. Flux ratios (observed/theoretical) range from 0.7 to 2.2, but most fall within the acceptable range of 0.7-1.5. Major rock-forming elements are carried by rivers as weathering products and there are minimal biogeochemical processes that modify these inputs as suspended particulate matter accumulates in the bottom sediments of the lake.

  18. Composition of Humic Acids of the Lake Baikal Sediments

    NASA Astrophysics Data System (ADS)

    Vishnyakova, O.; Chimitdorzhieva, G.; Andreeva, D.

    2012-04-01

    Humic substances are the final stage of the biogeochemical transformation of organic matter in the biosphere. Its natural compounds are found not only in soil, peat, coal, and sediments of basins. Chemical composition and properties of humic substances are determined by the functioning of the ecosystem as a whole. Therefore the study of the unique Lake Baikal sediments can provide information about their genesis, as well as the processes of organic matter transformation. For this purpose, preparations of humic acids (HA) were isolated by alkaline extraction method. The composition of HA was investigated by the elemental analyzer CHNS/O PerkinElmer Series II. Various located sediments of the Lake Baikal were the objects of the study: 1 - Chivyrkuisky Bay, 2 - Kotovo Bay, 3 - Selenga river delta near Dubinino village, 4 - Selenga river delta near Murzino village. Data on the elemental composition of HA in terms of ash-free portion show that the carbon content (CC) is of 50-53% with a maximum value in a sample 3, and minimum - in a sample 2. Such values are characteristic also for the soils with low biochemical activity. The hydrogen content is of 4,2-5,3%, a maximum value is in a sample 1. Data recalculation to the atomic percentages identified following regularities. The CC of HA is of 35-39 at. %. Hydrogen content is of 37-43 at. %. According to the content of these elements investigated substances are clearly divided into two groups: HA of the sediments of the Lake Baikal and river Selenga delta. The magnitude of the atomic ratio H/C can be seen varying degrees of condensation of the molecules of humic acids. The high atomic ratio H/C in HA of the former group indicates the predominance of aliphatic structures in the molecules. Humic acids of the later group are characterized by a low value H/C (<1), suggesting a large proportion of aromatic components in HA composition. In sediments of the Selenga river delta there is an addition of organic matter of terrigenous

  19. Results of vertical electric field monitoring in Lake Baikal

    NASA Astrophysics Data System (ADS)

    Korotaev, S. M.; Budnev, N. M.; Serdyuk, V. O.; Zurbanov, V. L.; Mirgazov, R. R.; Machinin, V. A.; Kiktenko, E. O.; Buzin, V. B.; Novysh, A. V.; Portyanskaya, I. A.

    2015-07-01

    The electric field of the hydrosphere can be used for monitoring various geophysical processes. Practical implementation of such monitoring requires sufficiently reliable measurements of the field and separation of the contributions from different sources. The present work endeavors to successively solve these tasks in the scope of the experiment on monitoring the vertical voltage in Lake Baikal. Similar monitoring has been conducted previously; however, insufficient reliability of the measurements limited the progress in data interpretation. Since then, we have designed a new instrumental complex, capable of highly accurate measurements and controlling the potential noise sources. For the first time, the flow-induced field is compared with the direct flow velocity measurements. The first results show the flow-induced field is predominant at periods of up to ten days. However, this analysis leaves unclear the origin of variations with a period of about 100 days.

  20. Amplitude blanking in seismic profiles from Lake Baikal

    USGS Publications Warehouse

    Lee, M.W.; Agena, W.F.; Hutchinson, D.R.

    1996-01-01

    Imaging of the deepest sedimentary section in Lake Baikal using multichannel seismic profiling was hampered by amplitude blanking that is regionally extensive, is associated with water depths greater than about 900 m and occurs at sub-bottom depths of 1-2 km in association with the first water-bottom multiple. Application of a powerful multiple suppression technique improved the quality of occasional discontinuous, dipping primary reflections, but failed to substantially alter the non-reflective character of the blanking zone. Detailed analysis of amplitudes from original data and synthetic models show that the threshold for detecting primary energy in deep water of Lake Baikal occurs when the primary is about 14-20 dB less than the multiple energy. The blanking occurs because of anomalously low reflectivities of the deep sediments coupled with this 20 dB limitation in real data processing. The blanking cuts across seismic stratal boundaries, and is therefore probably unrelated to depositional lithologies. The deepest, early rift deposits, inferred to come from a mixed fluvial and lacustrine setting, do not easily explain the widespread and uniform character of the blanked deposits. More likely, blanking occurs because of processes or phenomena that physically alter the deposits, causing them to be non-reflective and/or highly attenuating. No single process explains all the observations, but a combination of diagenesis, overpressure, and the presence of dispersed free gas at sub-bottom depths of 1-2 km, offer plausible and possible conditions that contribute to blanking. Copyright ?? 1996 Published by Elsevier Science Ltd.

  1. Tracing the sources of PCDD/Fs and PCBs in Lake Baikal

    SciTech Connect

    Mamontov, A.A.; Mamontova, E.A.; Tarasova, E.N.; McLachlan, M.S.

    2000-03-01

    Lake Baikal is a unique freshwater ecosystem that has been declared a UNESCO World Heritage Site. It contains high levels of PCBs, and Baikal seal were recently found to have PCDD/F concentrations comparable to those in the Baltic Sea. In this work fish and soil were analyzed to trace the sources of these compounds to the lake. The fish samples indicated that the PCDD/F and PCB contamination of Lake Baikal does not originate from background inputs and that the contamination increases from north to south. The soil inventory was determined at 34 sites around Lake Baikal and in the Angara River valley. For the PCDD/Fs and most PCBs, the soil inventory is a good approximation of the cumulative atmospheric deposition. It varied over a factor of 1,000, with the highest levels in Usol'ye Sibirskoe, a city 110 km north of the southwestern tip of the lake in the highly industrialized Angara River valley, and the lowest values in the pristine areas to the northeast of the lake. A continuous decrease in the soil inventory was observed moving from Usol'ye S. up the Angara River valley to Lake Baikal and from there northeastward along the lake.

  2. [Nitrogen-fixing cyanobacterium Trichormus variabilis of the lake Baikal phytoplankton].

    PubMed

    Gladkikh, A S; Belykh, O I; Klimenkov, I V; Tikhonova, I V

    2008-01-01

    A new filamentous cyanobacterial strain BAC 9610 was isolated from the lake Baikal pelagial. Data obtained by light, scanning, and transmission electron microscopy, along with 16S rRNA gene sequence analysis, allowed the bacterium identification as Trichormus variabilis, previously known as Anabaena variabilis. Trichormus is a cyanobacterial genus not presented in the list of Baikal plankton algae; A. variabilis also has not been previously detected in Baikal phytoplankton. T. variabilis nitrogen fixation ability was demonstrated. The gene responsible for nitrogen fixation, nifH, was identified by PCR and was partially sequenced. No hepatotoxin synthesis genes were revealed in the strain. PMID:19137721

  3. Tectonics of the baikal rift deduced from volcanism and sedimentation: a review oriented to the Baikal and Hovsgol lake systems.

    PubMed

    Ivanov, Alexei V; Demonterova, Elena I

    2009-01-01

    As known from inland sedimentary records, boreholes, and geophysical data, the initiation of the Baikal rift basins began as early as the Eocene. Dating of volcanic rocks on the rift shoulders indicates that volcanism started later, in the Early Miocene or probably in the Late Oligocene. Prominent tectonic uplift took place at about 20 Ma, but information (from both sediments and volcanics) on the initial stage of the rifting is scarce and incomplete. A comprehensive record of sedimentation derived from two stacked boreholes drilled at the submerged Akademichesky ridge indicates that the deep freshwater Lake Baikal existed for at least 8.4 Ma, while the exact formation of the lake in its roughly present-day shape and volume is unknown. Four important events of tectonic/environmental changes at about approximately 7, approximately 5, approximately 2.5, and approximately 0.1 Ma are seen in that record. The first event probably corresponds to a stage of rift propagation from the historical center towards the wings of the rift system. Rifting in the Hovsgol area was initiated at about this time. The event of ~5 Ma is a likely candidate for the boundary between slow and fast stages of rifting. It is reflected in a drastic change of sedimentation rate due to isolation of the Akademichesky ridge from the central and northern Lake Baikal basins. The youngest event of 0.1 Ma is reflected by the (87)0Sr/ (86)Sr ratio increase in Lake Baikal waters and probably related to an increasing rate of mountain growth (and hence erosion) resulting from glacial rebounding. The latter is responsible for the reorganization of the outflow pattern with the termination of the paleo-Manzurka outlet and the formation of the Angara outlet. The event of approximately 2.5 Ma is reflected in the decrease of the (87)Sr/(86)Sr and Na/Al ratios in Lake Baikal waters. We suggest that it is associated with a decrease of the dust load due to a reorganization of the atmospheric circulations in Mainland

  4. Typology of Fan Delta Morphologies at Lake Baikal, Siberia

    NASA Astrophysics Data System (ADS)

    Leuschner, Annette C.; Mattern, Frank; van Gasselt, Stephan

    2014-05-01

    The morphology and shape of river fans are a product of fluvial deposition and environmental conditions which are both subject to various controlling factors. Therefore, studies of fan delta morphologies not only aim at characterizing depositional environments but also at reconstructing the evolution of morphologies in order to describe past and present climate boundary conditions. By using remotely-sensed satellite imagery and digital elevation models, quantitative morphologic characteristics such as sizes of drainage basins, transport areas and areas of deposition can be derived from spatial analysis for large areas by semi-automatized procedures. In this work we conducted a comprehensive study of 33 fan deltas at Lake Baikal. Differentiation of individual typologies is based on previous work by [1] and [2]. Lake Baikal has been selected as study area because of its size, location and variable shore physiography and is considered well-suited for the study of the genesis of fan deltas and their controlling morphologic factors. For mapping of individual fan delta bodies multispectral images of the Landsat Enhanced Thematic Mapper (ETM) were used. For the determination of morphometric parameters as input data for subsequent hydrological studies, photogrammetrically derived digital terrain model data of the ASTER instrument as well as direct measurements obtained through the Shuttle Radar Topography Mission (SRTM) were utilized. Typical hydrodynamic factors are sizes of catchment areas, the morphometry of associated rivers and slope angles as well as sizes of fan deltas as summarized by [1] and [2] as so-called `influencing factors'. In contrast to earlier studies we separated different types of fans and analyzed them individually in order to relate shape and morphometry to environmental factors. Our analyses generally confirm that there is a positive correlation between e.g., fan areas and sizes of catchment areas as well as between fan areas and lengths of valley

  5. Mitochondrial DNA variability among Lake Baikal omul Coregonus autumnalis migratorius (Georgi)

    USGS Publications Warehouse

    Burnham-Curtis, M. K.; Ramme, T.M.; Todd, T.N.; Bronte, C.R.; Fleischer, G.W.; Pronin, N.M.; Maistrenko, S.G.

    2002-01-01

    Omul, Coregonus autumnalis, are a commercially important coregonine fish from Lake Baikal, Siberia, Russia. In Lake Baikal, three morphotypes recognized by fishery experts occupy different zones in the lake: they are referred to as "littoral," "pelagic," and "benthic". Expressed character divergence was supported by whole-body morphometric analysis, but it is not known whether discrete genetic differences accompany the observed morphological variation. This study was designed to assess the genetic variation of three different omul morphotypes sampled from different locations in Lake Baikal that were segregated by morphotype in multivariate analysis. We surveyed genetic variation with restriction fragment length polymorphism analysis of specific gene loci amplified with the polymerase chain reaction. Sequence variation was localized in the mitochondrial control region. Though no discrete genetic markers were found, there is evidence of reproductive segregation by geographic location that corroborates geographic variation in morphological characters.

  6. Mitochondrial DNA variability among Lake Baikal omul Coregonus autumnalis migratorius (Georgi)

    USGS Publications Warehouse

    Burnham-Curtis, Mary K.; Ramme, Tina M.; Todd, Thomas N.; Bronte, Charles R.; Fleischer, Guy W.; Pronin, Nikolai M.; Maistrenko, Sergei G.

    2002-01-01

    Omul, Coregonus autumnalis, are a commercially important coregonine fish from Lake Baikal, Siberia, Russia. In Lake Baikal, three morphotypes recognized by fishery experts occupy different zones in the lake; they are referred to as "littoral, " "pelagic, " and "benthic." Expressed character divergence was supported by whole-body morphometric analysis, but it is not known whether discrete genetic differences accompany the observed morphological variation. This study was designed to assess the genetic variation of three different omul morphotypes sampled from different locations in Lake Baikal that were segregated by morphotype in multivariate analysis. We surveyed genetic variation with restriction fragment length polymorphism analysis of specific gene loci amplified with the polymerase chain reaction. Sequence variation was localized in the mitochondrial control region. Though no discrete genetic markers were found, there is evidence of reproductive segregation by geographic location that corroborates geographic variation in morphological characters.

  7. An 84-kyr paleomagnetic record from the sediments of Lake Baikal, Siberia

    USGS Publications Warehouse

    Peck, J.A.; King, J.W.; Colman, Steven M.; Kravchinsky, V.A.

    1996-01-01

    We have conducted a paleomagnetic study of sediment cores obtained from the Selenga prodelta region of Lake Baikal, Russia. This record, which spans approximately the last 84 kyr, contributes to a better understanding of the nature of geomagnetic field behavior in Siberia and is a useful correlation and dating tool. We demonstrate that the Lake Baikal sediments are recording variations in the geomagnetic field. The directional record displays secular variation behavior with a geomagnetic excursion at 20 ka and additional excursions appearing as large-amplitude secular variation at 41, 61, and 67 ka. Smoothing of the geomagnetic excursion behavior occurs in Lake Baikal sediments owing to the intermediate sedimentation rate (13 cm kyr-1). The Lake Baikal relative paleointensity record correlates to absolute paleointensity data for the last 10 kyr and to relative paleointensity records from the Mediterranean Sea and Indian Ocean for the last 84 kyr. This correlation suggests a strong global (i.e., dipole) component to these records and further supports the reliability of sediments as recorders of relative geomagnetic paleointensity. We show that a relative geomagnetic intensity stratigraphy has a potential resolution of 7 kyr by correlating continental and marine records. The geomagnetic intensity stratigraphy helps constrain the age of the difficult to date Lake Baikal sediments.

  8. Differential bioaccumulation of potentially toxic elements in benthic and pelagic food chains in Lake Baikal.

    PubMed

    Ciesielski, Tomasz M; Pastukhov, Mikhail V; Leeves, Sara A; Farkas, Julia; Lierhagen, Syverin; Poletaeva, Vera I; Jenssen, Bjørn M

    2016-08-01

    Lake Baikal is located in eastern Siberia in the center of a vast mountain region. Even though the lake is regarded as a unique and pristine ecosystem, there are existing sources of anthropogenic pollution to the lake. In this study, the concentrations of the potentially toxic trace elements As, Cd, Pb, Hg, and Se were analyzed in water, plankton, invertebrates, and fish from riverine and pelagic influenced sites in Lake Baikal. Concentrations of Cd, Hg, Pb and Se in Lake Baikal water and biota were low, while concentrations of As were similar or slightly higher compared to in other freshwater ecosystems. The bioaccumulation potential of the trace elements in both the pelagic and the benthic ecosystems differed between the Selenga Shallows (riverine influence) and the Listvenichnyĭ Bay (pelagic influence). Despite the one order of magnitude higher water concentrations of Pb in the Selenga Shallows, Pb concentrations were significantly higher in both pelagic and benthic fish from the Listvenichnyĭ Bay. A similar trend was observed for Cd, Hg, and Se. The identified enhanced bioavailability of contaminants in the pelagic influenced Listvenichnyĭ Bay may be attributed to a lower abundance of natural ligands for contaminant complexation. Hg was found to biomagnify in both benthic and pelagic Baikal food chains, while As, Cd, and Pb were biodiluted. At both locations, Hg concentrations were around seven times higher in benthic than in pelagic fish, while pelagic fish had two times higher As concentrations compared to benthic fish. The calculated Se/Hg molar ratios revealed that, even though Lake Baikal is located in a Se-deficient region, Se is still present in excess over Hg and therefore the probability of Hg induced toxicity in the endemic fish species of Lake Baikal is assumed to be low. PMID:27130338

  9. AMS radiocarbon analyses from Lake Baikal, Siberia: Challenges of dating sediments from a large, oligotrophic lake

    USGS Publications Warehouse

    Colman, Steven M.; Jones, Glenn A.; Rubin, M.; King, J.W.; Peck, J.A.; Orem, W.H.

    1996-01-01

    A suite of 146 new accelerator-mass spectrometer (AMS) radiocarbon ages provides the first reliable chronology for late Quaternary sediments in Lake Baikal. In this large, highly oligotrophic lake, biogenic and authigenic carbonate are absent, and plant macrofossils are extremely rare. Total organic carbon is therefore the primary material available for dating. Several problems are associated with the TOC ages. One is the mixture of carbon sources in TOC, not all of which are syndepositional in age. This problem manifests itself in apparent ages for the sediment surface that are greater than zero. However, because most of the organic carbon in Lake Baikal sediments is algal (autochthonous) in origin, this effect is limited to about 1000+500 years, which can be corrected, at least for young deposits. The other major problem with dating Lake Baikal sediments is the very low carbon contents of glacial-age deposits, which makes them extremely susceptible to contamination with modern carbon. This problem can be minimized by careful sampling and handling procedures. The ages show almost an order of magnitude difference in sediment-accumulation rates among different sedimentary environments in Lake Baikal, from about 0.04 mm/year on isolated banks such as Academician Ridge, to nearly 0.3 mm/year in the turbidite depositional areas beneath the deep basin floors, such as the Central Basin. The new AMS ages clearly indicate that the dramatic increase in diatom productivity in the lake, as evidenced by increases in biogenic silica and organic carbon, began about 13 ka, in contrast to previous estimates of 7 ka for the age of this transition. Holocene net sedimentation rates may be less than, equal to, or greater than those in the late Pleistocene, depending on the site. This variability reflects the balance between variable terrigenous sedimentation and increased biogenic sedimentation during interglaciations. The ages reported here, and the temporal and spatial variation in

  10. Depositional and tectonic framework of the rift basins of Lake Baikal from multichannel seismic data

    USGS Publications Warehouse

    Hutchinson, D.R.; Golmshtok, A.J.; Zonenshain, L.P.; Moore, T.C.; Scholz, C.A.; Klitgord, Kim D.

    1992-01-01

    Recent multichannel seismic reflection data from Lake Baikal, located in a large, active, continental rift in central Asia, image three major stratigraphic units totalling 3.5 to 7.5 km thick in four subbasins. A major change in rift deposition and faulting between the oldest and middle-rift units probably corresponds to the change from slow to fast rifting. A brief comparison of the basins of Lake Baikal with those of the East African rift system highlights differences in structural style that can be explained by differences in age and evolution of the surrounding basement rocks. -from Authors

  11. Current ecosystem processes in steppe near Lake Baikal

    NASA Astrophysics Data System (ADS)

    Vanteeva, Julia

    2015-04-01

    The steppes and forest steppes complexes of Priol'khonie at the Lake Baikal (southern Siberia, Russia) were studied in this research. Recreational activity has a significant impact on the Priol'khonie region. During soviet time this area was actively used for agriculture. Nowadays, this territory is the part of Pribaikalskyi National Park and special protection is needed. As the landscapes satisfy different human demands there are many land-management conflicts. The specific climate and soil conditions and human activity lead to erosion processes on study area. Sediment loads are transferred into the Lake Baikal and cause water pollution. Consequently, vegetation cover and phytomass play an important role for regulating hydrological processes in the ecosystems. The process of phytomass formation and its proactive role playing on sedimentation and mitigate silt detaching by rill and inter-rill erosion are considered in the research as important indicators of the ecosystem functions for steppe landscapes. These indicators were studied for the different land cover types identified on the area because the study area has a large variety of steppe and forest steppe complexes, differing in the form of relief, soil types, vegetation species composition and degree of land degradation. The fieldwork was conducted in the study area in the July and August of 2013. Thirty-two experimental sites (10 x 10 m) which characterized different types of ecosystem were established. The level of landscape degradation was estimated. The method of clipping was used for the valuation of above-ground herbaceous phytomass. The phytomass of tree stands was calculated using the volume-conversion rates for forest-steppe complexes. For the quantification of transferred silt by inter-rill erosion in different conditions (vegetation, slope, soil type, anthropogenic load) a portable rainfall simulator was created with taking into account the characteristics of the study area. The aboveground

  12. The isolation and characterization of actinobacteria from dominant benthic macroinvertebrates endemic to Lake Baikal.

    PubMed

    Axenov-Gribanov, Denis; Rebets, Yuriy; Tokovenko, Bogdan; Voytsekhovskaya, Irina; Timofeyev, Maxim; Luzhetskyy, Andriy

    2016-03-01

    The high demand for new antibacterials fosters the isolation of new biologically active compounds producing actinobacteria. Here, we report the isolation and initial characterization of cultured actinobacteria from dominant benthic organisms' communities of Lake Baikal. Twenty-five distinct strains were obtained from 5 species of Baikal endemic macroinvertebrates of amphipods, freshwater sponges, turbellaria worms, and insects (caddisfly larvae). The 16S ribosomal RNA (rRNA)-based phylogenic analysis of obtained strains showed their affiliation to Streptomyces, Nocardia, Pseudonocardia, Micromonospora, Aeromicrobium, and Agromyces genera, revealing the diversity of actinobacteria associated with the benthic organisms of Lake Baikal. The biological activity assays showed that 24 out of 25 strains are producing compounds active against at least one of the test cultures used, including Gram-negative bacteria and Candida albicans. Complete dereplication of secondary metabolite profiles of two isolated strains led to identification of only few known compounds, while the majority of detected metabolites are not listed in existing antibiotic databases. PMID:26347255

  13. Water chemistry and plankton composition in the mixing zone of the Selenga River with Lake Baikal

    NASA Astrophysics Data System (ADS)

    Tomberg, Irina; Sorokovikova, larisa; Popovskaya, Galina; Belykh, Olga; Bashenkhaeva, Nadya; Parfenova, Valentina

    2014-05-01

    Seasonal and inter-annual variations of chemical components, bacterio- and phytoplankton and autotrophic picoplankton (APP) were studied in the distributaries of the Selenga River, Selenga shallow waters (Selenga shoal) and Lake Baikal for 2003-2013. Major variations in the chemical composition of river waters were recorded at a distance of 1-3 km off the mouths of the Selenga River distributaries (mixing zone). The total quantity of major ions and plankton composition and abundance served as indicators to distinguish between river and lake waters. Phytoplankton concentration was high in the mixing zone and caused the reduction of nutrients in this area. Changes in species composition of phytoplankton, APP, dominant groups of bacterioplankton were observed in the Selenga shoal. River phytoplankton prevailed near the mouths of distributaries, in the mixing zone these were replaced by lake species, and at a distance of 7 km offshore phytoplankton composition was typical of Lake Baikal. Organotrophic microorganisms dominated in the Selenga River water. In the mixing zone, all bacterial groups were represented in equal proportions. Oligotrophic and psychrotolerant bacteria prevailed in Lake Baikal. As the distance from the river delta increased, phycocyanin-rich picocyanobacteria were replaced by phycoerythrin-rich picocyanobacteria and the contribution of picoplankton biomass to total phytoplankton biomass was raised. Near the mouth of distributaries, APP biomass was 5 times lower than the phytoplankton biomass whilst at a distance of 7 km it was 2 times higher than typical values for Baikal phytoplankton.

  14. Conquest of the deep, old and cold: an exceptional limpet radiation in Lake Baikal.

    PubMed

    Stelbrink, Björn; Shirokaya, Alena A; Clewing, Catharina; Sitnikova, Tatiana Y; Prozorova, Larisa A; Albrecht, Christian

    2015-07-01

    Lake Baikal is the deepest, oldest and most speciose ancient lake in the world. The lake is characterized by high levels of molluscan species richness and endemicity, including the limpet family Acroloxidae with 25 endemic species. Members of this group generally inhabit the littoral zone, but have been recently found in the abyssal zone at hydrothermal vents and oil-seeps. Here, we use mitochondrial and nuclear data to provide a first molecular phylogeny of the Lake Baikal limpet radiation, and to date the beginning of intra-lacustrine diversification. Divergence time estimates suggest a considerably younger age for the species flock compared with lake age estimates, and the beginning of extensive diversification is possibly related to rapid deepening and cooling during rifting. Phylogenetic relationships and divergence time estimates do not clearly indicate when exactly the abyssal was colonized but suggest a timeframe coincident with the formation of the abyssal in the northern basin (Middle to Late Pleistocene). PMID:26202427

  15. Conquest of the deep, old and cold: an exceptional limpet radiation in Lake Baikal

    PubMed Central

    Stelbrink, Björn; Shirokaya, Alena A.; Clewing, Catharina; Sitnikova, Tatiana Y.; Prozorova, Larisa A.; Albrecht, Christian

    2015-01-01

    Lake Baikal is the deepest, oldest and most speciose ancient lake in the world. The lake is characterized by high levels of molluscan species richness and endemicity, including the limpet family Acroloxidae with 25 endemic species. Members of this group generally inhabit the littoral zone, but have been recently found in the abyssal zone at hydrothermal vents and oil-seeps. Here, we use mitochondrial and nuclear data to provide a first molecular phylogeny of the Lake Baikal limpet radiation, and to date the beginning of intra-lacustrine diversification. Divergence time estimates suggest a considerably younger age for the species flock compared with lake age estimates, and the beginning of extensive diversification is possibly related to rapid deepening and cooling during rifting. Phylogenetic relationships and divergence time estimates do not clearly indicate when exactly the abyssal was colonized but suggest a timeframe coincident with the formation of the abyssal in the northern basin (Middle to Late Pleistocene). PMID:26202427

  16. Ice patterns and hydrothermal plumes, Lake Baikal, Russia - Insights from Space Shuttle hand-held photography

    NASA Technical Reports Server (NTRS)

    Evans, Cynthia A.; Helfert, Michael R.; Helms, David R.

    1992-01-01

    Earth photography from the Space Shuttle is used to examine the ice cover on Lake Baikal and correlate the patterns of weakened and melting ice with known hydrothermal areas in the Siberian lake. Particular zones of melted and broken ice may be surface expressions of elevated heat flow in Lake Baikal. The possibility is explored that hydrothermal vents can introduce local convective upwelling and disrupt a stable water column to the extent that the melt zones which are observed in the lake's ice cover are produced. A heat flow map and photographs of the lake are overlaid to compare specific areas of thinned or broken ice with the hot spots. The regions of known hydrothermal activity and high heat flow correlate extremely well with circular regions of thinned ice, and zones of broken and recrystallized ice. Local and regional climate data and other sources of warm water, such as river inlets, are considered.

  17. Can silicon isotopes be used to assess anthropogenic impacts and nutrient utilisation in Lake Baikal, Siberia?

    NASA Astrophysics Data System (ADS)

    Swann, G. E. A.; Panizzo, V. N.; Mackay, A. W.; Roberts, S.; Vologina, E.; Horstwood, M. S.

    2014-12-01

    Silicon isotope geochemistry (28Si, 29Si, 30Si) represents a growing field in Earth Sciences providing information to constrain and understand biogeochemical cycling on land and in oceans. Here we present records of δ30Si (30Si/28Si) from the Lake Baikal drainage basin in central Siberia to understand silicon cycling through the dominant river tributaries and into Lake Baikal itself, the world's deepest and most voluminous lake containing one fifth of all freshwater not stored in glaciers and ice caps.Waters were collected along an upstream transect for the five dominant Lake Baikal inflows as well as from the Selenga Delta which account for >50% of the annual riverine flow to the lake. Samples for dissolved silicon (DSi) concentrations and silicon isotopic signatures (δ30SiDSi) were filtered and acidified in the field with isotopic analyses conducted on a Neptune + Multi-Collector ICP-MS using wet plasma mode with Mg doping of samples and standard-sample-standard bracketing. Analytical reproducibility is 0.11‰ (2σ) and blanks are <1% of signal intensity. The DSi concentration of all river inflow samples varies from c. 2.5-6.3 ppm, which contrasts with concentrations of < 1ppm from the Angara River, the lake's only outflow. Combined with river δ30SiDSi values of c. + 0.94 to +1.52‰ and lake water and outflow values of c. +2.50‰, the results show significant (up to 60%) biological utilisation of silicon entering the lake.With the Lake Baikal having been designated a World Heritage Site since 1996, due to its high level of biological endemicity, the work in combination with sediment cores from the lake provides an insight into the transportation and fate of silicon in the basin and an assessment of how climate change and expanding anthropogenic activities in the region including urbanisation, deforestation, agriculture and mining have impacted biogeochemical cycling.

  18. Influence of Long-Distance Climate Teleconnection on Seasonality of Water Temperature in the World's Largest Lake - Lake Baikal, Siberia

    PubMed Central

    Katz, Stephen L.; Hampton, Stephanie E.; Izmest'eva, Lyubov R.; Moore, Marianne V.

    2011-01-01

    Large-scale climate change is superimposed on interacting patterns of climate variability that fluctuate on numerous temporal and spatial scales—elements of which, such as seasonal timing, may have important impacts on local and regional ecosystem forcing. Lake Baikal in Siberia is not only the world's largest and most biologically diverse lake, but it has exceptionally strong seasonal structure in ecosystem dynamics that may be dramatically affected by fluctuations in seasonal timing. We applied time-frequency analysis to a near-continuous, 58-year record of water temperature from Lake Baikal to examine how seasonality in the lake has fluctuated over the past half century and to infer underlying mechanisms. On decadal scales, the timing of seasonal onset strongly corresponds with deviation in the zonal wind intensity as described by length of day (LOD); on shorter scales, these temperature patterns shift in concert with the El Nino-Southern Oscillation (ENSO). Importantly, the connection between ENSO and Lake Baikal is gated by the cool and warm periods of the Pacific Decadal Oscillation (PDO). Large-scale climatic phenomena affecting Siberia are apparent in Lake Baikal surface water temperature data, dynamics resulting from jet stream and storm track variability in central Asia and across the Northern Hemisphere. PMID:21359207

  19. Relationships and origin of endemic Lake Baikal gastropods (Caenogastropoda: Rissooidea) based on mitochondrial DNA sequences.

    PubMed

    Hausdorf, Bernhard; Röpstorf, Peter; Riedel, Frank

    2003-03-01

    The phylogenetic relationships and the origin of two groups of rissooid freshwater snails endemic to Lake Baikal were investigated using partial mitochondrial COI, 12S rDNA, and 16S rDNA sequences. The Baikalian Benedictiinae proved to be closely related to the Lithoglyphinae. According to a molecular clock estimate the two groups diverged in the Paleogene. The Benedictiinae might have evolved autochthonously in precursors of Lake Baikal. The Baikalian Baicaliidae are probably most closely related to the Amnicolidae and the Bithyniidae. These groups diverged at the latest during the Cretaceous. Thus the origin of the Baicaliidae predates the origin of the Baikal rift zone. The Baicaliidae evolved probably in other Central Asian freshwater reservoirs. However, the radiation of the extant Baicaliidae only started in the Neogene and might have occurred autochthonously in Lake Baikal. The conchological similarity of the Baicaliidae and the Pyrgulidae is due to convergence. The Pyrgulidae diverged from the common stem lineage of the other hydrobiid families at the latest in the Jurassic. The Bithyniidae is derived from hydrobiids and is related to the Amnicolidae. PMID:12644402

  20. A rock-magnetic record from Lake Baikal, Siberia: Evidence for Late Quaternary climate change

    USGS Publications Warehouse

    Peck, J.A.; King, J.W.; Colman, Steven M.; Kravchinsky, V.A.

    1994-01-01

    Rock-magnetic measurements of sediment cores from the Academician Ridge region of Lake Baikal, Siberia show variations related to Late Quaternary climate change. Based upon the well-dated last glacial-interglacial transition, variations in magnetic concentration and mineralogy are related to glacial-interglacial cycles using a conceptual model. Interglacial intervals are characterized by low magnetic concentrations and a composition that is dominated by low coercivity minerals. Glacial intervals are characterized by high magnetic concentrations and increased amounts of high coercivity minerals. The variation in magnetic concentration is consistent with dilution by diatom opal during the more productive interglacial periods. We also infer an increased contribution of eolian sediment during the colder, windier, and more arid glacial conditions when extensive loess deposits were formed throughout Europe and Asia. Eolian transport is inferred to deliver increased amounts of high coercivity minerals as staining on eolian grains during the glacial intervals. Variations in magnetic concentration and mineralogy of Lake Baikal sediment correlate to the SPECMAP marine oxygen-isotope record. The high degree of correlation between Baikal magnetic concentration/mineralogy and the SPECMAP oxygen-isotope record indicates that Lake Baikal sediment preserves a history of climate change in central Asia for the last 250 ka. This correlation provides a method of estimating the age of sediment beyond the range of the radiocarbon method. Future work must include providing better age control and additional climate proxy data, thereby strengthening the correlation of continental and marine climate records. ?? 1994.

  1. Bottom sediments and pore waters near a hydrothermal vent in Lake Baikal (Frolikha Bay)

    USGS Publications Warehouse

    Granina, L.Z.; Klerkx, J.; Callender, E.; Leermakers, M.; Golobokova, L.P.

    2007-01-01

    We discuss the redox environments and the compositions of bottom sediments and sedimentary pore waters in the region of a hydrothermal vent in Frolikha Bay, Lake Baikal. According to our results, the submarine vent and its companion nearby spring on land originate from a common source. The most convincing evidence for their relation comes from the proximity of stable oxygen and hydrogen isotope compositions in pore waters and in the spring water. The isotope composition indicates a meteoric origin of pore waters, but their major- and minor-element chemistry bears imprint of deep water which may seep through permeable faulted crust. Although pore waters near the submarine vent have a specific enrichment in major and minor constituents, hydrothermal discharge at the Baikal bottom causes a minor impact on the lake water chemistry, unlike the case of freshwater geothermal lakes in the East-African Rift and North America. ?? 2007.

  2. Crustal structure of central Lake Baikal: Insights into intracontinental rifting

    USGS Publications Warehouse

    ten Brink, U.S.; Taylor, M.H.

    2002-01-01

    The Cenozoic rift system of Baikal, located in the interior of the largest continental mass on Earth, is thought to represent a potential analog of the early stage of breakup of supercontinents. We present a detailed P wave velocity structure of the crust and sediments beneath the Central Basin, the deepest basin in the Baikal rift system. The structure is characterized by a Moho depth of 39-42.5 km; an 8-km-thick, laterally continuous high-velocity (7.05-7.4 km/s) lower crust, normal upper mantle velocity (8 km/s), a sedimentary section reaching maximum depths of 9 km, and a gradual increase of sediment velocity with depth. We interpret the high-velocity lower crust to be part of the Siberian Platform that was not thinned or altered significantly during rifting. In comparison to published results from the Siberian Platform, Moho under the basin is elevated by <3 km. On the basis of these results we propose that the basin was formed by upper crustal extension, possibly reactivating structures in an ancient fold-and-thrust belt. The extent and location of upper mantle extension are not revealed by our data, and it may be offset from the rift. We believe that the Baikal rift structure is similar in many respects to the Mesozoic Atlantic rift system, the precursor to the formation of the North Atlantic Ocean. We also propose that the Central Baikal rift evolved by episodic fault propagation and basin enlargement, rather than by two-stage rift evolution as is commonly assumed.

  3. Reexamining the long-term astronomical periodicities in the Lake Baikal deep drilling sediments

    NASA Astrophysics Data System (ADS)

    Kravchinsky, V. A.

    2009-05-01

    Records of climatic change, such as lacustrine and eolian sediments agree well with the marine records for the last couple million years. Continuous terrestrial records for longer time intervals were unavailable until last decade when deep drilling Lake Baikal cores were recovered. Lake Baikal's middle-high latitude position within the Asian interior ensures highest sensitivity of the climate to the Earth orbital parameter variations. Our earlier publications examined Milankovitch cyclicity in a number of the lake cores with ages spanning from the present day to 6.7 Ma. It was possible to demonstrate the high signal power in the narrow obliquity band confirming the strong orbital forcing on the climate. However, a 100 kyr period found in these records did not align with the orbital eccentricity in a way predicted by theory. Available Be10 chronology enabled me to adjust the magnetostratigraphy age model for certain time intervals and to revise the magnetic susceptibility and biogenic silica datasets. I compare both untuned and tuned datasets with the theoretical insolation and oceanic oxygen isotope records and discuss the findings of the precession, obliquity, and eccentricity cycles as well as "non-Milankovitch" cycles of ~29 kyr and ~70 kyr. A notable absence of considerable eccentricity amplitude at 400 kyr in the oceanic records during the last few million years is well known in spite of this being one of the largest component of eccentricity forcing. At the same time, reported earlier 400 kyr and larger periodicities for the Lake Baikal sedimentary records were derived from the erroneous age model. I reexamine the long-term periodicities (400 kyr and longer) which are confidently represented in the Lake Baikal records.

  4. Late Cretaceous-Cenozoic history of the Lake Baikal depression and formation of its unique biodiversity

    NASA Astrophysics Data System (ADS)

    Mats, V. D.; Shcherbakov, D. Yu.; Efimova, I. M.

    2011-08-01

    Independent methods of geological and molecular-biological chronologies have made it possible to define generally corresponding stages in the geological and biological evolution of the environments and communities of Lake Baikal since the Late Cretaceous, i.e., during the last 70 myr. All the abiotic elements drastically changed during geological evolution, with destruction of existing and formation of new natural complexes. Nevertheless, some specific zones retained relicts of former settings. The resulting present-day natural complex includes elements of different ages and geneses. Similar to different natural zones of the present-day Earth, which are populated by different biocoenoses, stages in the development of abiotic elements are also characterized by different faunal and floral assemblages. Some taxa were replaced by others, and the resulting aqueous biota of Lake Baikal includes different-age and ecologically different elements. The oldest groups of Baikal organisms appeared approximately 70 Ma ago, although the largest proportion of the lake biota started forming 4-3 Ma ago in response to the most drastic changes in the abiotic elements of the environment. The youngest taxa appeared 1.8 to 0.15 Ma ago, i.e., during the period when superdeep lake environments and mountainous glaciations were developing. The chronological coincidence of main stages in development of abiotic and biotic elements of the nature indicates their relationships. Particular transformations of abiotic elements and the probable mechanism of their influence on the evolution of living communities are also considered.

  5. Age and growth of pike (Esox lucius) in Chivyrkui Bay, Lake Baikal

    USGS Publications Warehouse

    Owens, Randall W.; Pronin, Nikolai M.

    2000-01-01

    The purpose of this study was to describe age and growth of pike (Esox lucius) in Lake Baikal. Pike were collected with gill nets and by angling in Chivyrkui Bay in late July-early August 1993 and by gill nets in June 1995. Total length (mm), weight (g), and sex were recorded and scales and cleithra were collected for aging. In 1993, pike, ages 1 to 3, ranged in length from 331 to 810 mm and in 1995 , pike, ages 2 to 10, ranged in length from 365 to 1,111 mm but only three percent were age 7 or older. Most growth in length occurred during the first two years of life. The length-weight relation for pike from Chivyrkui Bay was similar to that of pike from the St. Lawrence River. Calculated total length of pike from Lake Baikal equalled or exceeded the lengths of pike from lakes Erie or Ontario. Good agreement was found between ages from cleithra and from scales. Lengths at age in June 1995 (N=108) varied widely among pike. Females were generally larger than males at a given age among fish age-3 and older. When compared with the circumpolar growth standard, based on the von Bertalanffy growth curve, growth of Lake Baikal pike exceeded all other Asian populations, and equalled or exceeded many other northern hemisphere populations.

  6. Molecular evidence reveals a polyphyletic origin and chromosomal speciation of Lake Baikal's endemic asellid isopods.

    PubMed

    Hidding, B; Michel, E; Natyaganova, A V; Sherbakov, D Yu

    2003-06-01

    The six endemic isopod species of Lake Baikal have been regarded as a small species flock with uncertain affinities to related asellids. We provide evidence from 16S rRNA sequences for polyphyletic origins of Baikalian Asellidae. One clade of two species is related to the Eurasian genus Asellus. The other clade, Baicalasellus, shows affinities to North American asellids and may have a long evolutionary history within the lake basin. Some speciation events within Baicalasellus clearly have a chromosomal basis. In contrast with numerous taxa exhibiting monophyletic radiations in ancient lakes, the endemic Baikalian isopods arose by multiple invasions and chromosomal mechanisms. PMID:12755879

  7. Stratified distribution of nutrients and extremophile biota within freshwater ice covering the surface of Lake Baikal.

    PubMed

    Bondarenko, Nina A; Belykh, Olga I; Golobokova, Ludmila P; Artemyeva, Olga V; Logacheva, Natalia F; Tikhonova, Irina V; Lipko, Irina A; Kostornova, Tatyana Ya; Parfenova, Valentina V; Khodzher, Tamara V; Ahn, Tae-Seok; Zo, Young-Gun

    2012-02-01

    Biological entities and gradients of selected chemicals within the seemingly barren ice layers covering Lake Baikal were investigated. Ice cores 40-68 cm long were obtained from in shore and offshore sites of Southern Lake Baikal during the cold period of a year (March-April) in 2007 and 2008. In microscopic observations of the melted ice, both algae and bacteria were found in considerable numbers (>10(3) cells/L and >10(4) cells/ml, respectively). Among all organisms found, diatom was generally the most predominant taxon in the ice. Interestingly, both planktonic and benthic algae were present in considerable numbers (2-4×10(4) cells/L). Dominant phototrophic picoplankton were comprised of small green algae of various taxa and cyanobacteria of Synechococcus and Cyanobium. The bacterial community consisted mostly of short rod and cocci cells, either free-living or aggregated. Large numbers of yeast-like cells and actinomycete mycelium were also observed. Concentrations of silica, phosphorus, and nitrate were low by an order of magnitude where biota was abundant. The profile of the ice could be interpreted as vertical stratification of nutrients and biomass due to biological activities. Therefore, the organisms in the ice were regarded to maintain high activity while thriving under freezing conditions. Based on the results, it was concluded that the freshwater ice covering the surface of Lake Baikal is considerably populated by extremophilic microorganisms that actively metabolize and form a detritus food chain in the unique large freshwater ecosystem of Lake Baikal. PMID:22367932

  8. The Selenga River delta - a geochemical barrier for the waters of Lake Baikal

    NASA Astrophysics Data System (ADS)

    Chalov, Sergey; Thorslund, Josefin; Pietron, Jan; Jarsjö, Jerker

    2016-04-01

    Delta systems play an important role in retention of sediments and contaminants to downstream recipients, through processes such as gravitational sedimentation, flocculation and biofiltration. The Selenga river delta is one of the world's largest inland deltas, providing a huge buffer zone between Lake Baikal and upstream waters of the Selenga river basin. Understanding the delta functioning is critical for the planning of water management measures in the Selenga River Basin and for protection of the waters of Lake Baikal. We here study the current state and functioning of the delta's ecosystem and hydrogeochemical processes. More specifically, we considered spatio-temporal changes in water flow, morphology and transport of sediments and metals within the delta and what potential impacts these changes may have on the delta functions. Results show that the delta network has a large influence on the mass of metals reaching the Lake Baikal at the delta outlet. Regions with high density of wetlands and small channels, in contrast to main channel regions, show a consistent pattern of considerable contaminant filtering and removal (between 77-99% for key metals), during both high and low flow conditions, following with a significant increase (2-3 times) of bottom sediment pollution. Geomorphological processes also governs the barrier function of the delta, due to partitioning of flow between different channel systems. These results are particularly relevant in the light of recent and expected future changes involving both the hydrology and water quality in the Lake Baikal basin. Taken together, this emphasizes the importance of understanding the interface between flow partitioning, delta morphology, and sediment and metal patterns and storage rates for fully capturing and quantifying the variety in delta functions. This is particularly relevant coupled to hydroclimatic changes in the region, which could lead to significant decline in barrier functions of the delta due to

  9. Contemporary limnological and sedimentary analyses to investigate anthropogenic changes in nutrient fluxes at Lake Baikal, Siberia

    NASA Astrophysics Data System (ADS)

    Roberts, S.; McGowan, S.; Swann, G. E. A.; Mackay, A. W.; Panizzo, V.; Vologina, E.

    2014-12-01

    Large tectonic freshwater lakes face serious threats to their water quality, biological diversity and endemism through pollution and global warming. Lake Baikal is an important example as anthropogenic stressors (industrial pollution and cultural eutrophication) along with climate change could greatly affect the lake's unique ecosystem and pristine water conditions. Phosphorus, nitrogen and silica are thought to control phytoplankton development, however recent changes in nutrient impacts on Lake Baikal's phytoplankton remains unproven. This research aims to investigate the effect of anthropogenic and environmentally-driven changes on this large and biodiverse lake through seasonal sampling of the phytoplankton community (determined by chlorophyll and carotenoid pigments), chemical parameters (total phosphorus, dissolved organic carbon, silicate, nitrate and other major ions) and vertical profiles of pH, temperature and photosynethetically active radiation. Results show seasonal, vertical and spatial variability in the lake's phytoplankton biomass and composition with higher summer mixed-layer pigment concentrations in the south basin resulting in higher light attenuation coefficients and lower photic zone depths (R2=0.86, p < 0.05). Redundancy analysis shows that this distribution is primarily influenced by average dissolved organic carbon concentrations within the mixing layer, with the strongest negative correlation between picoplankton biomarkers and dissolved organic carbon concentrations (R2=-0.60, p < 0.05). Geochemical biomarkers (pigments and organic carbon [δ13Corganic]) from several sediment cores place these modern day observations within an historical context and allow the impact of past environmental changes on Lake Baikal's primary productivity over the last 60 years and natural climate-driven trends in past centuries to be assessed. These results show clear spatial and temporal changes between sites over this interval with greater increases in

  10. Raman spectroscopic and calorimetric observations on natural gas hydrates with cubic structures I and II obtained from Lake Baikal

    NASA Astrophysics Data System (ADS)

    Hachikubo, Akihiro; Khlystov, Oleg; Kida, Masato; Sakagami, Hirotoshi; Minami, Hirotsugu; Yamashita, Satoshi; Takahashi, Nobuo; Shoji, Hitoshi; Kalmychkov, Gennadiy; Poort, Jeffrey

    2012-12-01

    This study reports measurements of the Raman spectra of Lake Baikal gas hydrates and estimations of the hydration number of methane-rich samples. The hydration number of gas hydrates retrieved from the southern Baikal Basin (crystallographic structure I) was approx. 6.1. Consistent with previous results, the Raman spectra of gas hydrates retrieved from the Kukuy K-2 mud volcano in the central Baikal Basin indicated the existence of crystallographic structures I and II. Measurements of the dissociation heat of Lake Baikal gas hydrates by calorimetry (from the decomposition of gas hydrates to gas and water), employing the hydration number, revealed values of 53.7-55.5 kJ mol-1 for the southern basin samples (structure I), and of 54.3-55.5 kJ mol-1 for the structure I hydrates and 62.8-64.2 kJ mol-1 for the structure II hydrates from the Kukuy K-2 mud volcano.

  11. Molecular phylogenetic studies on the origin of biodiversity in Lake Baikal.

    PubMed

    Yu Sherbakov D

    1999-03-01

    Lake Baikal is host to some 2500 metazoan species, maybe more, the majority of which are endemic. When studies of the lake shifted from purely descriptive work to a more analytical approach in the second half of this century, the question of the origin of its fauna became central and is still one of the main challenges to researchers of Baikalian biodiversity. Current research is investigating whether biodiversity can be explained by a few adaptive radiations since the Miocene, whether it results from the accumulation of diversity throughout the whole history of the Baikalian rift zone (about 70 million years) or whether it stems from even older events. PMID:10322507

  12. Annotated checklist of the leech species diversity in the Maloe More Strait of Lake Baikal, Russia

    PubMed Central

    Kaygorodova, Irina A.

    2015-01-01

    Abstract In this paper, the very first checklist of the freshwater leeches of Maloe More Strait, a special part of Lake Baikal, is presented. It includes 14 free-living and parasitic species, of which four species belong to endemic Baikal genera – two species from Baicalobdella and one species each from Baicaloclepsis and Codonobdella. The checklist highlights six potentially new morphological species recorded for the first time in the area. The exact systematic position is stated for all leech species. Each species from the list is provided with information on taxonomic synonymy, data on its geographic distribution, and ecological characteristics. New species records are additionally provided with brief morphological characteristics and photos of their external morphology. PMID:26798292

  13. An Inventory of Underwater Landslides in Lake Baikal Suggests a Strong Link with Gas Hydrates

    NASA Astrophysics Data System (ADS)

    De Batist, M. A. O.; Naudts, L.; Casier, R.; Khlystov, O.; Khabuev, A.; Minami, H.; Grachev, M.; Shoji, H.

    2014-12-01

    Multibeam bathymetry data from Lake Baikal were analyzed for the identification of morphologies that could indicate the presence of underwater landslides. The data were collected in 2009 by a Belgian-Russian-Japanese consortium, using a 50 kHz Seabeam 1050 echosounder, operated from RV Titov. The data cover the entire lake floor -in water depths between 200 m and 1637 m- of the Southern and Central Basins, i.e. a total surface of 15,000 km2. Our analysis revealed the presence of 26 possible underwater landslides. At least 11 of these are characterized by distinctive headwalls, scars and overall morphology, and were confirmed to be mass-wasting features by high-resolution reflection seismic data. Most of the identified underwater landslides scar the slopes of the Selenga river delta, and the sediment-charged slopes of the shoaling eastern margin of the half-graben basins. Most of the underwater landslides have a headwall occurring at water depths between 300 and 450 m; only a few occur at larger water depths. All underwater landslides occur in areas in which gas hydrates have been inferred (i.e. based on the observation of bottom-simulating reflections on seismic data) or confirmed (i.e. by deep drilling or shallow coring). The clustering of many headwalls at a water depth that is not characterized by any distinct change in slope gradient or stratigraphy, but that is close to the stability limit of gas hydrates (i.e. ca. 380 m, for pure methane hydrates, under Lake Baikal conditions), suggests that the presence of the hydrates may be one of the most important controlling factors in conditioning the underwater slopes of Lake Baikal and rendering them unstable and prone to failure. The exact conditioning process remains, however, unclear as the hydrate reservoir in Lake Baikal is considered to have remained stable, even over relatively long time scales, in the absence of any important fluctuations in lake-level and in bottom-water temperature.

  14. Assessment of climate and land use changes impacts on the rivers inflow to the Lake Baikal

    NASA Astrophysics Data System (ADS)

    Kurovskaia, Victoriia; Semenova, Olga; Vinogradova, Tatyana

    2016-04-01

    Baikal is the deepest lake in the world and one of the biggest reservoirs of fresh water. The aim of this research was to analyze the long-term variability of characteristics of river inflow to the Lake using the historical data and project possible changes in the face of non-stationary climate and land use based on hydrological modelling. The basin of the Lake Baikal has area about 545 000 km2, half of which is situated in Russia. It is characterized by different climate and landscape conditions with annual flow depth varying from 30 to more than 600 mm. Nowadays active development and use of natural resources as well as climate changes have a strong impact on the regime of rivers inflow to the Lake. The watersheds response caused by environmental non-stationarity can be variable and unpredictable. Therefore adequate hydrological models with robust parametrization are required for future projections. This study consisted of two parts. Initially we compiled the database of daily runoff data for about 50 gauges in the basin of the Baikal Lake with continuous period of observations 30-50 years. The data was used to assess the characteristics of river inflow to the Lake for the historical period and estimate observed changes due to current climate change. For the development of future projections we have chosen several small and middle-size representative watersheds in different parts of the Lake basin with area from 151 to 7800 km2 and various types of hydrological regime. The data base for modelling was developed which included the information about landscapes, soils, dominating hydrological processes. The hydrological model parameters for different dominant landscapes were estimated based on that information. We applied distributed process-based hydrological model Hydrograph developed in State Hydrological Institute, Russia (Vinogradov et al., 2011; Semenova et al., 2013). It describes all essential processes of land hydrological cycle including detailed algorithm

  15. Molecular and isotopic characteristics of gas hydrate-bound hydrocarbons in southern and central Lake Baikal

    NASA Astrophysics Data System (ADS)

    Hachikubo, Akihiro; Khlystov, Oleg; Krylov, Alexey; Sakagami, Hirotoshi; Minami, Hirotsugu; Nunokawa, Yutaka; Yamashita, Satoshi; Takahashi, Nobuo; Shoji, Hitoshi; Nishio, Shin'ya; Kida, Masato; Ebinuma, Takao; Kalmychkov, Gennadiy; Poort, Jeffrey

    2010-06-01

    We investigated the molecular composition (methane, ethane, and propane) and stable isotope composition (methane and ethane) of hydrate-bound gas in sediments of Lake Baikal. Hydrate-bearing sediment cores were retrieved from eight gas seep sites, located in the southern and central Baikal basins. Empirical classification of the methane stable isotopes (δ13C and δD) for all the seep sites indicated the dominant microbial origin of methane via methyl-type fermentation; however, a mixture of thermogenic and microbial gases resulted in relatively high methane δ13C signatures at two sites where ethane δ13C indicated a typical thermogenic origin. At one of the sites in the southern Baikal basin, we found gas hydrates of enclathrated microbial ethane in which 13C and deuterium were both highly depleted (mean δ13C and δD of -61.6‰ V-PDB and -285.4‰ V-SMOW, respectively). To the best of our knowledge, this is the first report of C2 δ13C-δD classification for hydrate-bound gas in either freshwater or marine environments.

  16. [Vertical distribution of acanthocephalans of the order Echinorhynchida in Lake Baikal].

    PubMed

    Baldanova, D R

    2008-01-01

    Vertical distribution of acanthocephalans of the order Echinorhynchida is studied in Lake Baikal. Four species and subspecies from cottid fishes (Perciformes: Cottoidei) were examined, namely Pseudoechinorhynchus borealis (Linstow, 1901), Metechinorhynchus salmonis salmonis (Muller, 1780), M.s. baicalensis Bogolepova, 1957, M. truttae (Schrank, 1788). In the littoral (0-5 m) and sublittoral (5-100 m) areas all these species and subspecies were occurred, white in the profundal (100-300 m) and abyssal (900-1600 m) areas only Metechinorhynchus salmonis baisalensis has been found. PMID:18727364

  17. Diatom succession trends in recent sediments from Lake Baikal and their relation to atmospheric pollution and to climate change

    PubMed Central

    Mackay, A. W.

    1998-01-01

    Recent environmental change in Lake Baikal has been attributed to anthropogenic influences on the ecosystem, especially through pollution and cultural eutrophication. These hypotheses are tested in this paper principally by diatom analyses in 20 short sediment cores. Most of the cores were collected with a new type of box corer specifically designed for use on Lake Baikal. Most cores contain a good sediment record but turbidites occur in some sediment profiles which may be best recognized using a combination of techniques, such as radiometric dating and percentage dry weight analyses. The most recent sediments, especially those in the southern basin and in the very north of Baikal, contain a record of anthropogenic contamination in the form of lead and spheroidal carbonaceous particles, which confirms that the southern basin of Baikal is most affected by atmospheric sources of pollution. However, there is no sedimentary diatom evidence indicating offshore water quality deterioration in Baikal owing to air pollution or eutrophication. Small increases in diatoms which indicate nutrient enrichment (e.g. Stephanodiscus minutulus, Synedra acus v. radians and Synedra acus v. acus) may reflect local eutrophication of the shallow waters close to the Selenga Delta and certain coastal sites in the southern basin near to the Baikalsk paper and pulp mill. By using numerical techniques, Lake Baikal can be split into at least four regions on the basis of its surface sediment flora: the south, middle and north basins, and the shallow waters surrounding the Selenga Delta region. Diatom analyses reveal that the endemic flora of Lake Baikal has been constantly changing over at least the last 2000 years and that these fluctuations are probably responses to natural climatic variability. Recent sediments of Baikal may be affected by taphanomic processes (e.g. dissolution) and turbidite deposition, and these must be taken into account when interpreting the sedimentary diatom record. The

  18. Evolution of the hydro-climate system in the Lake Baikal basin

    NASA Astrophysics Data System (ADS)

    Törnqvist, Rebecka; Jarsjö, Jerker; Pietroń, Jan; Bring, Arvid; Rogberg, Peter; Asokan, Shilpa M.; Destouni, Georgia

    2014-11-01

    Climatic changes can profoundly alter hydrological conditions in river basins. Lake Baikal is the deepest and largest freshwater reservoir on Earth, and has a unique ecosystem with numerous endemic animal and plant species. We here identify long-term historical (1938-2009) and projected future hydro-climatic trends in the Selenga River Basin, which is the largest sub-basin (>60% inflow) of Lake Baikal. Our analysis is based on long-term river monitoring and historical hydro-climatic observation data, as well as ensemble mean and 22 individual model results of the Coupled Model Intercomparison Project, Phase 5 (CMIP5). Study of the latter considers a historical period (from 1961) and projections for 2010-2039 and 2070-2099. Observations show almost twice as fast warming as the global average during the period 1938-2009. Decreased intra-annual variability of river discharge over this period indicates basin-scale permafrost degradation. CMIP5 ensemble projections show further future warming, implying continued permafrost thaw. Modelling of runoff change, however, is highly uncertain, with many models (64%) and their ensemble mean failing to reproduce historical behaviour, and with indicated future increase being small relative to the large differences among individual model results.

  19. Evidence from Lake Baikal for Siberian glaciation during oxygen-isotope substage 5d

    USGS Publications Warehouse

    Karabanov, E.B.; Prokopenko, A.A.; Williams, D.F.; Colman, Steven M.

    1998-01-01

    The paleoclimatic record from bottom sediments of Lake Baikal (eastern Siberia) reveals new evidence for an abrupt and intense glaciation during the initial part of the last interglacial period (isotope substage 5d). This glaciation lasted about 12 000 yr from 117 000 to 105 000 yr BP according to correlation with the SPEC-MAP isotope chronology. Lithological and biogeochemical evidence of glaciation from Lake Baikal agrees with evidence for the advance of ice sheet in northwestern Siberia during this time period and also with cryogenic features within the strata of Kazantzevo soils in Southern Siberia. The severe 5d glaciation in Siberia was caused by dramatic cooling due to the decrease in solar insolation (as predicted by the model of insulation changes for northern Asia according to Milankovich theory) coupled with western atmospheric transport of moisture from the opea areas of Northern Atlantic and Arctic seas (which became ice-free due to the intense warming during preceeding isotope substage 5e). Other marine and continental records show evidence for cooling during 5d, but not for intense glaciation. Late Pleistocene glaciations in the Northern Hemisphere may have begun in northwestern Siberia.

  20. Impact of Placer Mining on Sediment Transport in Headwaters of the Lake Baikal Basin.

    NASA Astrophysics Data System (ADS)

    Pietron, J.; Jarsjo, J.; Chalov, S.

    2015-12-01

    Adverse practices in alluvial surface mining (placer mining) can lead to shifts in sediment transport regimes of rivers. However, some placer mines are located in remote parts of river basins, which constrain data availability in mining impact assessments. One such mining area is the Zaamar Goldfield (Northern Mongolia) which stretches 60 km along the Tuul River. The area is located in the headwaters of the Lake Baikal Basin, and may impact the UNESCO World Heritage Site of Lake Baikal. Previous studies indicate that the mining industry in the Zaamar Goldfield loads the river system with considerable amount of contaminated sediments (heavy metals). Still, transport processes and possible changes in local to regional sediment transport need to be better understood. In this work, we use snapshot field measurements and various flow and transport modelling techniques to analyze (1) the impact of placer mining in the sediment delivery to the river system and (2) the dynamics of further sediment transport to downstream Tuul River. Our results indicate that surface mining operations and waste management have considerable impact on the sediment input from the landscape. Furthermore, dynamic in-channel storage of sediments can act as intermittent sources of mining sediments. These effects occur in addition to impacts of on-going changes in hydro-climatic conditions of the area. We hope that our methodology and results will aid in studying similar unmonitored and mining-affected river basins.

  1. A qualitative assessment of the influence of bioturbation in Lake Baikal sediments

    NASA Astrophysics Data System (ADS)

    Martin, Patrick; Boes, Xavier; Goddeeris, Boudewijn; Fagel, Nathalie

    2005-04-01

    The impact of bioturbation in Lake Baikal sediments, particularly on rhythmic layering and mixing, was assessed by studying the actual vertical distribution of benthic animals in continuous accumulation zones selected by seismic survey (Vydrino Shoulder, Posolskoe Bank, Continent Ridge). To assess the influence of the bioturbation, animals were extracted from short cores and identified at the relevant taxonomic level. The faunal distribution is examined in parallel with the bioturbation tracks observed in thin section. Oligochaeta, Nematoda, Ostracoda, Copepoda, Gammaridae, Chironomidae and Hydrachnidia were found inhabiting the sediment. Among them, only oligochaete worms were assumed to have a significant impact on sediment mixing because of their "conveyor belt" feeding. The other two most abundantly sampled groups, nematods and copepods, belong to the interstitial fauna that has no significant impact on the vertical displacement of sediment particles and do not ingest the sediment. The presence of a benthic fauna as deep as 15 cm in the sediment indicates that the possibility of sediment disturbance by invertebrate activity cannot be dismissed in Lake Baikal. The effect of biological mixing is more limited in the deepest stations because the number of potential bioturbators is reduced, qualitatively as well as quantitatively. Located in the abyssal zone, Continent and Vydrino (but outside turbidites) deep stations appear to be most promising sediment records for tracking climate signal at high resolution.

  2. A preliminary investigation of siliceous microfossil succession in late quaternary sediments from Lake Baikal, Siberia

    USGS Publications Warehouse

    Julius, M. L.; Stoermer, E. F.; Colman, S. M.; Moore, T. C.

    1997-01-01

    Siliceous microfossil assemblage succession was analyzed in a 100 m sediment core from Lake Baikal, Siberia. The core was recovered from the lake's central basin at a water depth of 365 m. Microfossil abundance varied greatly within the intervals sampled, ranging from samples devoid of siliceous microfossils to samples with up to 3.49 x 1011 microfossils g-1 sediment. Fluctuations in abundance appear to reflect trends in the marine δ18O record, with peak microfossil levels generally representing climate optima. Microfossil taxa present in sampled intervals changed considerably with core depth. Within each sample a small number of endemic diatom species dominated the assemblage. Changes in dominant endemic taxa between sampled intervals ranged from extirpation of some taxa, to shifts in quantitative abundance. Differences in microfossil composition and the association of variations in abundance with climate fluctuations suggest rapid speciation in response to major climatic excursions.

  3. Faunal communities at sites of gas- and oil-bearing fluids in Lake Baikal

    NASA Astrophysics Data System (ADS)

    Zemskaya, Tamara I.; Sitnikova, Tatiana Y.; Kiyashko, Sergei I.; Kalmychkov, Gennady V.; Pogodaeva, Tatiana V.; Mekhanikova, Irina V.; Naumova, Tatiana V.; Shubenkova, Olga V.; Chernitsina, Svetlana M.; Kotsar, Oleg V.; Chernyaev, Evgeny S.; Khlystov, Oleg M.

    2012-12-01

    Macro- and meiofaunal communities were examined at four geomorphologically distinct sites with different gas- and oil-bearing fluid characteristics in the northern, central and southern basins of Lake Baikal. All sites had elevated concentrations of bicarbonate, nitrate, sulphate and chloride ions in pore fluids, with highest values at the Frolikha vent. Elevated levels of iron ions were found in pore waters of the St. Petersburg methane seep and the Gorevoy Utes oil seep. The chemical composition of pore waters at the Malenky mud volcano was similar to that reported in earlier work. Consistent with published data, the Frolikha vent (northern basin) and the St. Petersburg methane seep (central basin) were characterised by methane of mixed genesis (thermogenic + biogenic), whereas the methane source was mainly thermogenic at the Gorevoy Utes oil seep (central basin) and biogenic at the Malenky mud volcano (southern basin). In contrast to marine seep ecosystems, the macrofauna was dominated only by amphipods, giant planarians and oligochaetes, whereas bivalves were absent; the meiofauna was similar to its marine counterpart, being dominated by nematodes, cyclops, harpacticoids and ostracods. A statistically significant positive relationship was revealed between faunal abundance and the availability of bacterial mats on seep sediments. Moreover, ANOVA tests showed significant increases in both meiozoobenthic and macrozoobenthic densities at "hot spot" vent/seep sites relative to discharge-free reference sites. The isotopic composition of carbon and nitrogen at various trophic levels of these benthic vent/seep communities was found to differ markedly from that reported by earlier studies for the pelagic and other benthic food webs in Lake Baikal. As in marine seeps, the macrofauna had variable isotopic signatures. Light δ13C and δ15N values suggest the utilization of chemosynthetically fixed and/or methane-derived organic matter. By contrast, the heavy δ13C

  4. Ecology of Siberian Taimen Hucho taimen in the Lake Baikal Basin

    USGS Publications Warehouse

    Matveyev, Arcadi N.; Pronin, Nikolai M.; Samusenok, Vitali P.; Bronte, Charles R.

    1998-01-01

    Taimen Hucho taimen historically inhabited most tributaries and littoral areas of Lake Baikal, in south central Siberia, where they supported subsistence and commercial fisheries. Logging, pollution, and overfishing have caused dramatic population declines or local extinction of most stocks. Most of what is known about this species has been published in eastern journals and therefore is not readily available to western scientists. New data collected during the 1980s and 1990s have been combined with other reports to provide an overview of the biology and life history of this species. Taimen are long-lived fish and can reach ages of 29 years and sizes up to 60 kg. Populations can either be strictly riverine or anadromous. Adults from both life histories ascend rivers in spring to spawn and feed, and less extensive migrations occur in fall to prey on spawning omul (Coregonus autumnalis migratorius). Principal food items for age 1 and 2 taimen are macroinvertebrates, but young taimen quickly become piscivorous at age 2 when they consume mainly black Baikal grayling (Thymallus arcticus baicalensis), and sculpins (Taracottus kneri, Cottus kesslerij). Males reach sexual maturity at ages 7 to 8 and later for females at ages 8 to 9. Average egg production per female was about 22,000 eggs. Parasite burdens are heavy but composed of few species and mediated by prey items consumed. This fish is a highly-specialized predator and plays an indispensable role in the structure of fish communities in mountains and foothills. Taimen conservation in the Baikal region is impossible without adoption and implementation of a dedicated rehabilitation program that includes the protection of remaining populations and habitat, and possibly introduction of hatchery-reared fish in selected areas where habitat remains, but parental stocks are low.

  5. Climate Induced Birch Mortality in Trans-Baikal Lake Region, Siberia

    NASA Technical Reports Server (NTRS)

    Kharuk, V. I.; Ranson, K. J.; Oskorbin, P. A.; Im, S. T.; Dvinskaya, M. L.

    2013-01-01

    The Trans-Baikal (or Zabailkal'e) region includes the forest-steppe ecotones south and east of Lake Baikal in Russia and has experienced drought for several years. The decline and mortality of birch (Betula pendula) stands within the forest-steppe ecotone Trans-Baikal region was studied based on a temporal series of satellite data, ground measurements, and tree ring analysis. During the first decade of the 21st century birch stands decline and mortality were observed on )about 5% of the total area of stands within our 1250 km(exp 2 study area. Birch forest decline and mortality occurs mainly at the margins of stands, within the forest-steppe ecotone on slopes with direct insolation. During the first decade of the 21st century summer (June-August) precipitation was about 25% below normal. Soil water content measurements were lowest within dead stands and highest within healthy stands and intermediate within damaged stands. Drought impact on stands was amplified by an increase in summer air temperatures (+0.9 C) in comparison with the previous decade. Tree ring data of ''surviving'' and ''dead'' tree groups showed a positive correlation with summer/annual precipitation and negative correlation with summer air temperatures. Temperature and precipitation extreme anomalies tend to occur in the region with a period of about 27 years. The observed anomaly was the most severe since the beginning of meteorological observations in the year 1900. Data for the other sites showed a positive climate impact on the growth and expansion of Siberian forests. That is, the same species (B. pendula) showed considerable increase (1.4 times both in height and stem volume) during 20th-21st centuries as temperature increased but precipitation remained at adequate levels.

  6. A cellular and metabolic assessment of the thermal stress responses in the endemic gastropod Benedictia limnaeoides ongurensis from Lake Baikal.

    PubMed

    Axenov-Gribanov, Denis V; Bedulina, Daria S; Shatilina, Zhanna M; Lubyaga, Yulia A; Vereshchagina, Kseniya P; Timofeyev, Maxim A

    2014-01-01

    Our objective was to determine if the Lake Baikal endemic gastropod Benedictia limnaeoides ongurensis, which inhabits in stable cold waters expresses a thermal stress response. We hypothesized that the evolution of this species in the stable cold waters of Lake Baikal resulted in a reduction of its thermal stress-response mechanisms at the biochemical and cellular levels. Contrary to our hypothesis, our results show that exposure to a thermal challenge activates the cellular and biochemical mechanisms of thermal resistance, such as heat shock proteins and antioxidative enzymes, and alters energetic metabolism in B. limnaeoides ongurensis. Thermal stress caused the elevation of heat shock protein 70 and the products of anaerobic glycolysis together with the depletion of glucose and phosphagens in the studied species. Thus, a temperature increase activates the complex biochemical system of stress response and alters the energetic metabolism in this endemic Baikal gastropod. It is concluded that the deepwater Lake Baikal endemic gastropod B. limnaeoides ongurensis retains the ability to activate well-developed biochemical stress-response mechanisms when exposed to a thermal challenge. PMID:24076104

  7. Estimate of the vertical plankton biomass profile on the basis of measurements of fluorescent characteristics in pelagial of Lake Baikal

    NASA Astrophysics Data System (ADS)

    Panchenko, Mikhail V.; Sakirko, Maria V.; Usoltseva, Marina V.; Popovskaya, Galina I.; Domysheva, Valentina M.; Shimaraev, Mikhail N.; Zavoruev, Valerii V.; Pestunov, Dmitrii A.

    2014-11-01

    We study the effect of physical, chemical and biological processes on gas exchange of CO2 in the air-water system in Lake Baikal. Photosynthesis of aquatic biota is known to play a crucial role in changing the concentration of carbon dioxide in the water. Fluorescent methods are considered to be of high performance in problems of determining quantitative characteristics of biomass, however they require preliminary calibration directly for a specific type of plankton. In the pelagic zone of Lake Baikal the species composition, quantitative and spatial distribution of phytoplankton are characterized by strong spatial and temporal variability. Therefore, the fluorescent devices calibration on a single reference does not provide acceptable accuracy of quantitative assessment of the biomass. The results discussed in the paper were obtained by shipboard measurements during the Baikal campaign of 2010-2011. Correlation between the biomass in 25-meter water layer and the integral value of the fluorescent signal in this layer was obtained for calibration. The report discusses the advantages and disadvantages of the chosen methods and the results of retrieval of the vertical profiles of the biomass for stations in the pelagic zone of Lake Baikal in spring for the 2010-2011 biennium.

  8. Continental climate response to orbital forcing from biogenic silica records in Lake Baikal

    USGS Publications Warehouse

    Colman, Steven M.; Peck, J.A.; Karabanov, E.B.; Carter, Susan J.; Bradbury, J.P.; King, J.W.; Williams, D.F.

    1995-01-01

    CHANGES in insolation caused by periodic changes in the Earth's orbital parameters provide the primary forcing for global ice ages1-6. But it is not clear to what extent the climates in continental interiors are controlled directly by regional variations in insolation and to what extent they are driven instead by the highly nonlinear response of the oceans and ice sheets. Here we investigate this question using the record of biogenic silica in Lake Baikal as a proxy for climate change in this high-latitude mid-continental region. We find a good correlation between this record and that of marine oxygen isotopes4. Over the past 250 kyr the Baikal record exhibits both a strongly nonlinear component (manifested in a 100-kyr periodicity) and weaker direct-insolation components (manifested in the 41-kyr (obliquity) and 23- and 19-kyr (precession) orbital cycles). These results show that even though extreme continental climates such as this are influenced directly by insolation variations, they are dominated by the nonlinear rhythm of the oceans and ice sheets.

  9. Identification of a putatively multixenobiotic resistance related Abcb1 transporter in amphipod species endemic to the highly pristine Lake Baikal.

    PubMed

    Pavlichenko, Vasiliy V; Protopopova, Marina V; Timofeyev, Maxim; Luckenbach, Till

    2015-04-01

    The fauna of Lake Baikal in Eastern Siberia, the largest freshwater body on Earth, is characterized by high degrees of biodiversity and endemism. Amphipods, a prominent taxon within the indigenous fauna, occur in an exceptionally high number of endemic species. Considering the specific water chemistry of Lake Baikal with extremely low levels of potentially toxic natural organic compounds, it seems conceivable that certain adaptions to adverse environmental factors are missing in endemic species, such as cellular defense mechanisms mitigating toxic effects of chemicals. The degree to which the endemic fauna is affected by the recently occurring anthropogenic water pollution of Lake Baikal may depend on the existence of such cellular defense mechanisms in those species. We here show that endemic amphipods express transcripts for Abcb1, a major component of the cellular multixenobiotic resistance (MXR) defense against toxic chemicals. Based on a partial abcb1 cDNA sequence from Gammarus lacustris, an amphipod species common across Northern Eurasia but only rarely found in Lake Baikal, respective homologous sequences were cloned from five amphipods endemic to Lake Baikal, Eulimnogammarus verrucosus, E. vittatus, E. cyaneus, E. marituji, and Gmelinoides fasciatus, confirming that abcb1 is transcribed in those species. The effects of thermal (25 °C) and chemical stress (1-2 mg L(-1) phenanthrene) in short-term exposures (up to 24 h) on transcript levels of abcb1 and heat shock protein 70 (hsp70), used as a proxy for cellular stress in the experiments, were exemplarily examined in E. verrucosus, E. cyaneus, and Gammarus lacustris. Whereas increases of abcb1 transcripts upon treatments occurred only in the Baikalian species E. verrucosus and E. cyaneus but not in Gammarus lacustris, changes of hsp70 transcript levels were seen in all three species. At least for species endemic to Lake Baikal, the data thus indicate that regulation of the identified amphipod abcb1 is

  10. Lidar profiling of aerosol optical properties from Paris to Lake Baikal (Siberia)

    NASA Astrophysics Data System (ADS)

    Dieudonné, E.; Chazette, P.; Marnas, F.; Totems, J.; Shang, X.

    2014-11-01

    In June 2013, a ground-based mobile lidar performed the 10 000 km ride from Paris to Ulan-Ude, near Lake Baikal, profiling for the first time aerosol optical properties all the way from Western Europe to central Siberia. The instrument was equipped with N2-Raman and depolarization channels that enabled an optical speciation of aerosols in the low and middle troposphere. The backscatter-to-extinction ratio (BER) and particle depolarization ratio (PDR) at 355 nm have been retrieved. The BER in the lower boundary layer (300-700 m) was found to be 0.017 ± 0.009 sr-1 in average during the campaign, with slightly higher values in background conditions near Lake Baikal (0.021 ± 0.010 sr-1 in average) corresponding to dust-like particles. PDR values observed in Russian cities (>1.7%) are higher than the ones measured in European cities (<1.3%) due to the lifting of terrigenous aerosols by traffic on roads with a bad tarmac. Biomass burning layers from grassland or/and forest fires in southern Russia exhibit BER values ranging from 0.010 to 0.015 sr-1 and from 2 to 3% for the PDR. Desert dust aerosols originating from the Caspian and Aral seas regions were characterized for the first time, with a BER (PDR) of 0.022 sr-1 (21%) for pure dust, and 0.011 sr-1 (15%) for a mix between dust and biomass burning. The lidar observations also showed that this dust event extended over 2300 km and lasted for ~6 days. Measurements from the Moderate Resolution Imaging Spectrometer (MODIS) show that our results are comparable in terms of aerosol optical thickness (between 0.05 and 0.40 at 355 nm) with the mean aerosol load encountered throughout our route.

  11. A 9,000 Year History of Seal Hunting on Lake Baikal, Siberia: The Zooarchaeology of Sagan-Zaba II.

    PubMed

    Nomokonova, Tatiana; Losey, Robert J; Goriunova, Ol'ga I; Novikov, Alexei G; Weber, Andrzej W

    2015-01-01

    Sagan-Zaba II, a habitation site on the shore of Siberia's Lake Baikal, contains a record of seal hunting that spans much of the Holocene, making it one of the longest histories of seal use in North Asia. Zooarchaeological analyses of the 16,000 Baikal seal remains from this well-dated site clearly show that sealing began here at least 9000 calendar years ago. The use of these animals at Sagan-Zaba appears to have peaked in the Middle Holocene, when foragers used the site as a spring hunting and processing location for yearling and juvenile seals taken on the lake ice. After 4800 years ago, seal use declined at the site, while the relative importance of ungulate hunting and fishing increased. Pastoralists began occupying Sagan-Zaba at some point during the Late Holocene, and these groups too utilized the lake's seals. Domesticated animals are increasingly common after about 2000 years ago, a pattern seen elsewhere in the region, but spring and some summer hunting of seals was still occurring. This use of seals by prehistoric herders mirrors patterns of seal use among the region's historic and modern groups. Overall, the data presented in the paper demonstrate that Lake Baikal witnessed thousands of years of human use of aquatic resources. PMID:26009890

  12. Mass transport on the slope of Kukuy Griva of Lake Baikal: results of the TTR-Class@Baikal expeditions in 2014 and 2015

    NASA Astrophysics Data System (ADS)

    Solovyeva, Marina; Akhmanov, Grigorii; Starovoitov, Anatoly; Khlystov, Oleg; Khabuev, Andrey; Chensky, Aleksandr; Mazzini, Adriano; Tokarev, Mikhail; Giliazetdinova, Dina

    2016-04-01

    A large submarine landslide area of Lake Baikal was studied in 2014 and 2015 during two recent expeditions of the Training-Through-Research Class@Baikal project onboard RV "G.Yu. Vereshchagin". The sliding, discovered in 2009, affects the north-western slope of the so-called Kukuy Griva, an elevation situated within the underwater delta front of the Selenga river. Selenga is the largest river flowing to the Baikal Lake and the very high sedimentation rates occurring in this area result in broad mass transport processes along the slope. In 2014 a number of sparker seismic lines were acquired and several gravity cores were collected in order to map the distribution of the individual slump bodies. Seismic imaging revealed the presence of two main sedimentary units within the uppermost 200 meters. These units are characterized by differently expressed bedding and by different degree of inner deformation. Three seismic-facies within the upper unit and two seismic-facies within the lower unit were described and interpreted in terms of genesis. This interpretation outlined two periods in the Quaternary history of mass transport processes on the Kukuy Griva slope. Recent sliding events were observed particularly in the upper part of the slope. Typically these displaced bodies do not extend over large surfaces and are not characterized by significant inner deformations. In addition, to the north of Kukuy Griva a large well-expressed landslide head scarp was mapped. The buried landslides in the lower units are characterized by relatively large individual bodies comprising highly deformed sediments and covered with well-stratified non-deformed sediments. The different characteristics of the slide bodies that are confined in the upper and in the lower sedimentary units, likely result from variations in sedimentation rate and in the composition of the supplied sediment during the glacial periods. Eventual fluctuations in the lake water level can also explain these differences

  13. A Holocene molluscan succession from floodplain sediments of the upper Lena River (Lake Baikal region), Siberia

    NASA Astrophysics Data System (ADS)

    White, Dustin; Preece, Richard C.; Shchetnikov, Alexander A.; Parfitt, Simon A.; Dlussky, Konstantin G.

    2008-05-01

    Floodplain sediments of the upper Lena River near Basovo in south-central Siberia have yielded the most detailed Holocene molluscan succession yet reported from the entire eastern Palaearctic. Over 72,500 shells from at least 28 species of terrestrial and 23 species of freshwater mollusc have been recovered, an abundance and diversity far higher than previously reported from the region. The molluscan assemblages are dominated by land snails, especially members of the genus Vallonia, represented by five species including Vallonia tenuilabris and two poorly known species Vallonia kamtschatica and Vallonia cf. chinensis. Other noteworthy species recovered include Gastrocopta theeli, Carychium pessimum, Vertigo extima (southernmost record), Vertigo microsphaera and the first Asian records of three other taxa ( Vertigo geyeri, Vertigo genesii and Vertigo parcedentata). Illustrations are provided for the critical species, since opinions differ about the status of various taxa and the correct names that should be used. The molluscan assemblages show clear successional trends during the early to mid-Holocene, reflecting episodes of dryness/wetness on the floodplain. Drier conditions at ca 6350 14C yr BP coincide with major changes in the archaeological record seen at other sites in the region but it remains unclear whether the two are linked. A prominent charcoal-rich horizon dated to ca 2800 14C yr BP marks a burning event in the catchment, which resulted in a two-fold increase in sediment accumulation rate. Remains of small mammals occurred throughout the sequence including a tooth of Microtus cf. maximowiczii, possibly the first occurrence of Ungar vole west of Lake Baikal. The faunal analyses have been integrated with a detailed pedological study of the sedimentary profile and a chronology was obtained by means of 12 AMS radiocarbon dates. This study provides the first detailed palaeoecological information relating to Holocene molluscan assemblages from the Cis-Baikal

  14. Endemic Lake Baikal sponges from deep water. 1: Potential cryptic speciation and discovery of living species known only from fossils.

    PubMed

    Itskovich, Valeria B; Kaluzhnaya, Oxana V; Veynberg, Elena; Erpenbeck, Dirk

    2015-01-01

    We revealed new deep-water species and cryptic speciation within freshwater sponges of the endemic family Lubomirskiidae (Porifera; Demospongiae; Spongillina) based on molecular and spicule morphology analyses of ITS and CO1 mtDNA. Lubomirskiidae contains a group of closely related species which are a dominant component of the benthos in Lake Baikal, the world's deepest and most ancient lake. Spicule morphology was similar between two Recent samples and species only known previously from fossils in Late Pliocene (3.2-2.8 mya) sediments. Despite the morphological similarity with the cosmopolitan family Spongillidae, molecular analysis of ITS sequences has reliably assigned these species to Lubomirskiidae. This not only indicates that species identification of freshwater fossil sponge spicules should be made with caution, but also suggests that the structure of megascleres may not be a reliable character for interpretations of paleoclimatic reconstructions for the Baikal region. Our results do not support the current classification of Lubomirskiidae into its morphologically defined genera and species, suggesting a strong discrepancy between molecular and morphological variation in Baikalian sponges. This present contribution is the first part of a study on the phylogenetic relationships of the Lake Baikal deep water sponge fauna. PMID:26250223

  15. A 9,000 Year History of Seal Hunting on Lake Baikal, Siberia: The Zooarchaeology of Sagan-Zaba II

    PubMed Central

    Goriunova, Ol’ga I.; Novikov, Alexei G.; Weber, Andrzej W.

    2015-01-01

    Sagan-Zaba II, a habitation site on the shore of Siberia’s Lake Baikal, contains a record of seal hunting that spans much of the Holocene, making it one of the longest histories of seal use in North Asia. Zooarchaeological analyses of the 16,000 Baikal seal remains from this well-dated site clearly show that sealing began here at least 9000 calendar years ago. The use of these animals at Sagan-Zaba appears to have peaked in the Middle Holocene, when foragers used the site as a spring hunting and processing location for yearling and juvenile seals taken on the lake ice. After 4800 years ago, seal use declined at the site, while the relative importance of ungulate hunting and fishing increased. Pastoralists began occupying Sagan-Zaba at some point during the Late Holocene, and these groups too utilized the lake’s seals. Domesticated animals are increasingly common after about 2000 years ago, a pattern seen elsewhere in the region, but spring and some summer hunting of seals was still occurring. This use of seals by prehistoric herders mirrors patterns of seal use among the region’s historic and modern groups. Overall, the data presented in the paper demonstrate that Lake Baikal witnessed thousands of years of human use of aquatic resources. PMID:26009890

  16. Sediment transport dynamics linked to morphological evolution of the Selenga River delta, Lake Baikal, Russia

    NASA Astrophysics Data System (ADS)

    Dong, T. Y.; Nittrouer, J.; McElroy, B. J.; Czapiga, M. J.; Il'icheva, E.; Pavolv, M.; Parker, G.

    2014-12-01

    The Selenga River delta, Lake Baikal, Russia, is approximately 700 km2 in size and contains three active lobes that receive varying amounts of water and sediment discharge. This delta represents a unique end-member in so far that the system is positioned along the deep-water (~1500 m) margin of Lake Baikal and therefore exists as a shelf-edge delta. In order to evaluate the morphological dynamics of the Selenga delta, field expeditions were undertaken during July 2013 and 2014, to investigate the morphologic, sedimentologic, and hydraulic nature of this delta system. Single-beam bathymetry data, sidescan sonar data, sediment samples, and aerial survey data were collected and analyzed to constrain: 1) channel geometries within the delta, 2) bedform sizes and spatial distributions, 3) grain size composition of channel bed sediment as well as bank sediment, collected from both major and minor distributary channels, and 4) elevation range of the subaerial portion of the delta. Our data indicate that the delta possesses downstream sediment fining, ranging from predominantly gravel and sand near the delta apex to silt and sand at the delta-lake interface. Field surveys also indicate that the Selenga delta has both eroding and aggrading banks, and that the delta is actively incising into some banks that consist of terraces, which are defined as regions that are not inundated by typical 2- to 4-year flood discharge events. Therefore the terraces are distinct from the actively accreting regions of the delta that receive sedimentation via water inundation during regular river floods. We spatially constrain the regions of the Selenga delta that are inundated during floods versus terraced using a 1-D water-surface hydrodynamic model that produces estimates of stage for flood water discharges, whereby local water surface elevations produced with the model are compared to the measured terrestrial elevations. Our analyses show that terrace elevations steadily decrease downstream

  17. Biogenic silica in Lake Baikal sediments: results from 1990-1992 American cores

    USGS Publications Warehouse

    Carter, Susan J.; Colman, Steven M.

    1994-01-01

    The Lake Baikal Paleoclimate Project is a joint Russian-American program established to study the paleoclimate of Central Asia. During three summer field seasons, duplicate Russian and American cores were taken at a number of sites in different sedimentary environments in the lake. Eight cores returned to the U.S. were quantitatively analyzed for biogenic silica using a single-step 5-hour alkaline leach, followed by dissolved silicon analysis by inductively-coupled-plasma atomic-emission spectroscopy. Sediments of Holocene age in these cores have biogenic silica maxima that range from about 15 to 80 percent. An underlying zone in each core with low biogenic-silica concentrations (0 to 5 percent) dates from the last glacial maximum. The transition from the last glaciation to the present interglaciation, recorded by biogenic silica, began about 13,000 years ago. Biogenic silica profiles from these cores appear to be a good measure of past diatom productivity and a useful basis for paleoclimatic interpretations.

  18. Stock structure of Lake Baikal omul as determined by whole-body morphology

    USGS Publications Warehouse

    Bronte, Charles R.; Fleischer, G.W.; Maistrenko, S.G.; Pronin, N.M.

    1999-01-01

    In Lake Baikal, three morphotypes of omul Coregonus autumnalis migratorius are recognized; the littoral, pelagic, and deep-water forms. Morphotype assignment is difficult, and similar to that encountered in pelagic and deep-water coregonines in the Laurentian Great Lakes. Principal component analysis revealed separation of all three morphotypes based on caudal peduncle length and depth, length and depth of the body between the dorsal and anal fin, and distance between the pectoral and the pelvic fins. Strong negative loadings were associated with head measurements. Omul of the same morphotype captured at different locations were classified to location of capture using step-wise discriminant function analysis. Jackknife correct classifications ranged from 43 to 78% for littoral omul from five locations, and 45–86% for pelagic omul from four locations. Patterns of location misclassification of littoral omul suggested that the sub-population structure, hence stock affinity, may be influenced by movements and intermixing of individuals among areas that are joined bathymetrically. Pelagic omul were more distinguishable by site and may support a previous hypothesis of a spawning-based rather than a foraging-based sub-population structure. Omul morphotypes may reflect adaptations to both ecological and local environmental conditions, and may have a genetic basis.

  19. Atmospheric methanethiol emitted from a pulp and paper plant on the shore of Lake Baikal

    NASA Astrophysics Data System (ADS)

    Toda, Kei; Obata, Tomoaki; Obolkin, Vladimir A.; Potemkin, Vladimir L.; Hirota, Kazutoshi; Takeuchi, Masaki; Arita, Shou; Khodzher, Tamara V.; Grachev, Michael A.

    2010-07-01

    On-site measurement of methanethiol (CH 3SH) was performed for three years on ships and cars near a pulp and paper plant standing on the shore of Lake Baikal in Siberia, Russia, to investigate the behavior and impact of atmospheric CH 3SH emitted from a point source. Despite its strong odor, there are few reports on atmospheric CH 3SH, while many investigations have been carried out on dimethyl sulfide (DMS). In this work, CH 3SH and DMS were measured every 15 min by a recently developed automated instrument based on single column trapping/separation and chemiluminescence measurement. Hydrogen sulfide, sulfur dioxide and ozone were also measured simultaneously by individual instruments. Of these sulfur compounds, CH 3SH was dominant and its concentration sometimes reached several tens of ppbv. The concentration of CH 3SH was high at night, because of the lack of photodecomposition and local winds from the mountain to the lake. Such time variation was marked in the summer. The CH 3SH level decreased significantly downwind, while decreases in concentrations of other compounds such as DMS and SO 2 were relatively small. From these temporal and spatial variations, the behavior of CH 3SH is described in this paper. The impact of CH 3SH near the Siberian big sources is discussed with the presented data.

  20. Diurnal behavior of the carbon dioxide flux and change in the isotopic ratio δ13C in surface and near-bottom water in littoral of Lake Baikal

    NASA Astrophysics Data System (ADS)

    Panchenko, Mikhail V.; Domysheva, Valentina M.; Padalko, Natalia L.; Chernikov, Eugenii V.; Prazdnichnykh, Maxim I.; Tumakov, Alexander G.; Pestunov, Dmitrii A.

    2014-11-01

    Lake Baikal is one of the unique natural environments in Siberia which, to a large extent, affects the state of the nature in this region. The processes of gas exchange in the "water-atmosphere" system have been studied in Lake Baikal since 2002. The main purpose of the integrated investigations of exchange of carbon-containing gases in the water-atmosphere system in Lake Baikal is to study the contribution of physical, chemical, and biological components of the process and their interrelation with the intensity and rhythms of the fluxes. In 2013, the integrated measurements in the littoral area of Baikal were complemented with studies of the diurnal dynamics of isotopic ratio δ 13C in the surface and near-bottom water, which were not yet performed in Baikal before. In this work, we analyze first results of the joint analysis of RO2 fluxes in the "atmosphere - water surface" system and δ 13C, obtained in August 2013 in the littoral area of South Baikal. It is shown that d13C markedly increases in the surface waters at daylight time. In nighttime period, there takes place a reverse process, when δ 13C of the surface water approaches δ 13C, which is recorded for near-bottom water.

  1. Uranium-series disequilibrium, sedimentation, diatom frustules, and paleoclimate change in Lake Baikal.

    SciTech Connect

    Edgington, D. N.; Robbins, J. A.; Colman, S. M.; Orlandini, K. A.; Gustin, M.-P.; Environmental Research; Univ. of Wisconsin; NOAA; US Geological Survey

    1996-09-01

    The large volume of water, approximately one-fifth of the total surface fresh water on the planet, contained in Lake Baikal in southeastern Siberia is distinguished by having a relatively high concentration of uranium (ca. 2 nM), and, together with the surface sediments, an unusually high {sup 234}U{sup 238}U alpha activity ratio of 1.95. About 80% of the input of uranium to the lake, with a {sup 234}U{sup 238}U ratio of 2.0, comes from the Selenga River. Profiles of uranium, as well as the extent of isotopic disequilibrium in a 9 m sediment core collected on Academic Ridge, generally show high values during interglacial periods corresponding to high diatom frustule numbers (DiFr) and biogenic silica (BSi) data that have been reported elsewhere. During glacial periods (low DiFr and BSi), uranium progeny ({sup 234}U and {sup 230}Th) were in secular equilibrium with low concentrations of their parent {sup 238}U. Radionuclide distributions were interpreted in terms of a quantitative model allowing for adsorption of riverine inputs of uranium onto two classes of sedimenting particles with differing {sup 238}U{sup 232}Th ratios and uranium progeny in secular equilibrium. If the {sup 234}U{sup 238}U activity ratio of adsorbed uranium has remained constant, mean sedimentation rates can be independently estimated as 3.6 {+-} 0.6 and 3.7 {+-} 0.9 cm x kyr{sup -1} for the decay of {sup 234}U and in-growth of {sup 230}Th, respectively. These rates are consistent with a mean rate of 3.76 cm x kyr{sup -1}, calculated by optimization of the correspondence between adsorbed {sup 238}U and {delta}{sup 18}O in dated oceanic sediments. The adsorbed uranium apparently tracks variable river flow during interglacials and is drastically reduced during periods of glaciation. Evidently, uranium has not been significantly redistributed within Baikal sediments over at least the past 250 kyr and is a unique, biologically non-essential, tracer for climate-sensitive processes, which provide

  2. Uranium-series disequilibrium, sedimentation, diatom frustules, and paleoclimate change in Lake Baikal

    USGS Publications Warehouse

    Edgington, D.N.; Robbins, J.A.; Colman, Steven M.; Orlandini, K.A.; Gustin, M.-P.

    1996-01-01

    The large volume of water, approximately one-fifth of the total surface fresh water on the planet, contained in Lake Baikal in southeastern Siberia is distinguished by having a relatively high concentration of uranium (ca. 2 nM), and, together with the surface sediments, an unusually high 234U/238U alpha activity ratio of 1.95. About 80% of the input of uranium to the lake, with a 234U/238U ratio of 2.0, comes from the Selenga River. Profiles of uranium, as well as the extent of isotopic disequilibrium in a 9 m sediment core collected on Academic Ridge, generally show high values during interglacial periods corresponding to high diatom frustule numbers (DiFr) and biogenic silica (BSi) data that have been reported elsewhere. During glacial periods (low DiFr and BSi), uranium progeny (234U and 230Th) were in secular equilibrium with low concentrations of their parent 238U. Radionuclide distributions were interpreted in terms of a quantitative model allowing for adsorption of riverine inputs of uranium onto two classes of sedimenting particles with differing 238U/232Th ratios and uranium progeny in secular equilibrium. If the 234U/238U activity ratio of adsorbed uranium has remained constant, mean sedimentation rates can be independently estimated as 3.6 ?? 0.6 and 3.7 ?? 0.9 cm ?? kyr-1 for the decay of 234U and in-growth of 230Th, respectively. These rates are consistent with a mean rate of 3.76 cm ?? kyr-1, calculated by optimization of the correspondence between adsorbed 238U and ??18O in dated oceanic sediments. The adsorbed uranium apparently tracks variable river flow during interglacials and is drastically reduced during periods of glaciation. Evidently, uranium has not been significantly redistributed within Baikal sediments over at least the past 250 kyr and is a unique, biologically non-essential, tracer for climate-sensitive processes, which provide their own internal geochronometers, potentially useful for ages up to 1 Myr BP.

  3. Deep water renewal in Lake Baikal: A model for long-term analyses

    NASA Astrophysics Data System (ADS)

    Piccolroaz, Sebastiano; Toffolon, Marco

    2013-12-01

    The phenomenon of deep water renewal in the South Basin of Lake Baikal is investigated by means of a simplified one-dimensional model. The downwelling process, whereby large volumes of superficial, cold, and oxygenated water periodically sink to the lake bottom (>1400m) due to thermobaric instability, is simulated by means of three main submodules: a reaction-diffusion equation for temperature and other tracers, and two Lagrangian algorithms, the first for the vertical stabilization of unstable density regions (including thermobaric effects) and the second handling the downwelling mechanism. A self-consistent procedure for the dynamical reconstruction of the diapycnal diffusivity profile is included to account for the effect of the variability of external conditions. The model has been developed aimed at providing a detailed description of deep-ventilation and a quantification of its consequences at the basin scale; the core algorithms have been designed suitably to perform long-term simulations (hundreds of years) and to deal with a limited amount of information about boundary conditions, which are expressed in terms of wind forcing and surface water temperature. The main parameters have been calibrated using measured profiles of temperature and chlorofluorocarbons (CFC-12) concentration over a 40 year historical period. A long-term simulation (one millennium), in which the current meteorological conditions have been kept statistically unchanged, has been used to determine the asymptotic dynamics. The results are consistent with previous measurements and estimates, suggesting that the model is suitable to qualitatively and quantitatively simulate deep water renewal in deep, temperate lakes, capturing the relative contribution and interaction of the different processes involved.

  4. Information support of territorial wildlife management of Lake Baikal and the surrounding areas (Russia)

    NASA Astrophysics Data System (ADS)

    Lesnykh, Svetlana

    2013-04-01

    The UNESCO World Heritage Committee inscribed Lake Baikal in the World Heritage List under all four natural criteria as the most outstanding example of a freshwater ecosystem. It is the oldest and deepest lake in the world, which is the main freshwater reserve surrounded by a system of protected areas that have high scientific and natural values. However, there is a conflict between three main interests within the territory: the preservation of the unique ecosystem of the lake and its surrounding areas, the need for regional economic development, and protection of interests of the population, living on the shores of Lake Baikal. Solutions to the current challenges are seen in the development of control mechanisms for the wildlife management to ensure sustainable development and conservation of lake and the surrounding regions. For development mechanisms of territorial management of the complex and valuable area it is necessary to analyze features of its functioning and self-control (adaptable possibilities), allowing ecosystems to maintain their unique properties under influence of various external factors: anthropogenic (emissions, waste water, streams of tourists) and natural (climate change) load. While determining the direction and usage intensity of the territory these possibilities and their limits should be considered. Also for development of management strategy it is necessary to consider the relation of people to land and water, types of wildlife management, ownership, rent, protection from the negative effects, and etc. The relation of people to the natural area gives a chance to prioritize the direction in the resource use and their protection. Results of the scientific researches (reaction of an ecosystem on influence of various factors and system of relations to wildlife management objects) are the basis for the nature protection laws in the field of wildlife management and environmental protection. The methodology of legal zoning of the territory was

  5. Ethmolaimus riparius sp. n. and Paramononchus major sp. n. (Nematoda) from Lake Baikal, Russia.

    PubMed

    Gagarin, Vladimir G; Naumova, Tatyana V

    2016-01-01

    Two new nematode species found in Lake Baikal (Russia) are described and illustrated. Ethmolaimus riparius sp. n. is morphologically close to E. pilosus Shoshin, 1998 and E. lanatus Shoshin, 1998. The new species differs from E. pilosus by the longer and thinner body (L = 1228-1501 µm, a = 26-34 vs L = 720-1070 µm, a = 19-23), larger stoma (26-32 µm long vs 19-24 µm long), longer spicules and gubernaculum (45-50 µm long and 21-25 µm long vs accordingly 32-37 µm long and 8 µm long). E. riparius sp. n. differs from E. lanatus by the longer body (L = 1228-1501 µm vs L = 680-1180), shorter cephalic setae (its length is equal 1.1-1.4 labial region diameter vs 1.6-2.1 labial region diameter) and longer spicules and gubernaculum (45-50 µm long and 21-25 µm long vs accordingly 25-30 µm long and 7-8 µm long). Paramononchus major sp. n is close to P. orientalis Gagarin & Naumova, 2012, but differs from it by the longer body (L = 5926-7820 µm vs L = 3081-3778 µm), longer spicules (410-475 µm long vs 208-238 µm long) and larger number of precloacal supplements (52-61 vs 21-24). Keys for the identification of valid species of the genera Ethmolaimus and Paramononchus are given. PMID:27394603

  6. Reinvestigation of age model for relative paleointensity stack and application to Lake Baikal record

    NASA Astrophysics Data System (ADS)

    Oda, H.

    2014-12-01

    The age model for relative paleointensity stack PISO-1500 (Channell et al., 2009) is based on IODP U1308 from North Atlantic. Channell et al. (2008) developed the age model for U1308 by correlating the benthic oxygen isotope curve with LR04 oxygen isotope stack (Lisiecki&Raymo, 2005). LR04 stack is known as oxygen isotope stack for benthic foraminifarra, whose age model is dependent on ice volume model with a certain time lag. On the other hand, Caballero-Gill et al. (2012) developed an absolute age model based on U-Th dating for stalagmites from China and correlated the oxygen isotope curve with that on planctonic foraminiferra for a deep-sea core from South China Sea. The age model based on absolute dating for stalagmite was then transfered to oxygen isotope curve of benthic forraminiferra for the same core. This enables to provide absolute age model on PISO-1500 for the past 350 kyrs. The resulting modified PISO-1500 was applied on paleomagnetic records from Lake Baikal to provide an age model based on relative paleointensity. Finally, this age model was compared with alternative age model based on correlation of biogenic silica record with insolation at the site (Prokopenko et al., 2006) and the reason for the discrepancy will be discussed.

  7. Land use changing and land use optimization of Lake Baikal basin on the example of two key areas

    NASA Astrophysics Data System (ADS)

    Solodyankina, S.

    2012-04-01

    Lake Baikal contains roughly 20% of the world's unfrozen surface fresh water. It was declared a UNESCO World Heritage Site in 1996. Today levels of urbanization and economic stress on environmental resources is increasing on the shorts of the lake Baikal. The potential of economic development (industry, local tourism, and mining) of the Severobaykalsky and Sludyansky districts is rather high although they are characterized not only by beneficial features for local economy but also by considerable disadvantages for nature of this world valuable territory. This investigation show human-caused landscape changes during economic development of the two key areas in Baikal water catchment basin during 10 years (point of reference is 2000 year). Key areas are 1) the Baikalo-Patomskoe highland in the north of the Baikal catchment basin (Severobaykalsky district, Republic of Buryatia); 2) Khamar-Daban mountain system in the south of the Baikal catchment basin (Sludyansky districy, Irkutsk region). Since 2000 year land use of the territory has changed. Areas of agriculture were reduced but recreation activity on the bank of the lake was increased. Methods of GIS analysis and local statistic analysis of landscape characteristic were used. Nature, rural and urban areas ratio are estimated. Vegetation and soil condition assessment were made. The essence of this research is in helping to make decisions linked to upcoming problems: situation identification, evaluation and forecasting of the potential landscape condition, optimization of land use, mitigation of impact and mapping of territories and nature resources which have a high ecological value or endangered by industrial impact. For this purpose landscape maps of the territories on the base of the remote sensing information and field investigations were created. They used to calculate potential landscape functions of the territory without taking into account present impact of anthropogenic actions. Land use maps for years

  8. Morphology and Sediment Transport Dynamics of the Selenga River Delta, Lake Baikal, Russia

    NASA Astrophysics Data System (ADS)

    Dong, T. Y.; Il'icheva, L.; Nittrouer, J. A.; Pavolv, M.

    2013-12-01

    The Selenga River fan delta is a lacustrine system located in southeastern Siberia, Russia, where Selenga River flows into Lake Baikal. The Selenga River is the largest source of sediment and water entering Lake Baikal. Covering ~550 km2, the Selenga delta is one of the largest freshwater deltas in the world. Evaluating the Selenga delta and its morphology is very important for local residents who rely upon the delta for both ecological and agricultural welfare. However, a sediment budget remains poorly constrained, as do estimates for the partitioning of water and sediment amongst the numerous bifurcating delta channels. This information is critical for addressing how the delta morphology evolves and influences the stratigraphic composition of the delta. To investigate the morphological characteristics of the delta, a field expedition was undertaken during July 2013 in collaboration with Russian scientists. The overall goal of the field work was to constrain delta dynamics through data collection. Field measurements included single-beam bathymetry data and sidescan sonar data to characterize: 1) channel geometries of the delta; 2) bedform sizes and distribution; and 3) grain-size composition of the channel bed. Flow velocity measurements were collected within the bifurcating channels to measure water discharge. Bedload samples were obtained within the active distributary channels to measure downstream sediment fining. Additionally, channel island cores were collected in order to analyze the internal architecture of the delta. The data reveal a systematic downstream sediment fining, from a predominantly gravel bed near the delta apex, to a fine-sand bed at the delta-lake interface (~40 km total distance). Bathymetry data document how width-to-depth ratios systematically decrease downstream in association with increasing channel bifurcations and decreasing channel-bed grain size. Furthermore, the investigations reveal that the delta is actively terraced, with the

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  10. Gold mining impact on riverine heavy metal transport in a sparsely monitored region: the upper Lake Baikal Basin case.

    PubMed

    Thorslund, Josefin; Jarsjö, Jerker; Chalov, Sergey R; Belozerova, Ekaterina V

    2012-10-26

    Mining and ore excavation can cause the acidification and heavy metal pollution of downstream water systems. It can be difficult to assess the load contributions from individual mining areas, which is commonly required for environmental impact assessments. In the current study, we quantified the net impact of the unmonitored mining activities in the Zaamar Goldfield (Mongolia) on heavy metal transport in the downstream Tuul River-Selenga River-Lake Baikal water systems. We also noted that the Zaamar site shares the conditions of limited monitoring with many rapidly developing regions of the world. The heavy metal concentrations and flow data were obtained from historical measurement campaigns, long-term monitoring, and a novel field campaign. The results indicate that natural mass flows of heavy metals in dissolved form increased by an order of magnitude because of mining. Prevailing alkaline conditions in the vicinity of Zaamar can limit the dissolution, maintaining the on-site concentrations below health-risk based guideline values. However, suspended river concentrations are much higher than the dissolved concentrations. The placer gold mining at the Zaamar site has increased the total riverine mass flows of Al, As, Cu, Fe, Mn, Pb and Zn by 44.300, 30.1, 65.7, 47.800, 1.480, 76.0 and 65.0 tonnes per year respectively. We suggest that local to regional transformation and enrichment processes in combination with suspended sediment transport from numerous existing upstream mining areas contribute to high concentrations of dissolved heavy metals in downstream parts of the Selenga River, including its delta area at Lake Baikal. Furthermore, single hydrological events can increase the suspended load concentrations by at least one order of magnitude. Overall, the Selenga River Basin, which drains into Lake Baikal, should be recognised as one of the world's most impacted areas with regard to heavy metal loads, and it contributes to 1% and 3% of the world flux of

  11. Orbital forcing of continental climate during the Pleistocene: a complete astronomically-tuned climatic record from Lake Baikal, SE Siberia

    NASA Astrophysics Data System (ADS)

    Prokopenko, A. A.; Hinnov, L. A.; Williams, D. F.; Kuzmin, M. I.

    2007-12-01

    Baikal was the first ancient rift lake where an ODP-style coring technology was used to recover a spectacular continuous paleoclimate record . Glacial/interglacial diatom productivity cycles recorded as biogenic silica content variations in sediments reveals strong power in Milankovitch frequency bands. By splicing BDP-96-1 and BDP- 96-2 drill cores, we generated a composite BDP-96 BioSi record over the entire Pleistocene. During the present interglacial, Lake Baikal biogenic silica (BioSi) proxy response is anti-phased with the early Holocene regional humidity indices. Instead, BioSi closely follows a significant rise in regional annual temperature reflected in palynological records and predicted by GCM simulations around 6 ka. In terms of orbital configuration, this time corresponds to September perihelion (SP), 4-5 ka past June insolation maximum. The Holocene-like BioSi timing is confirmed by observations during the last interglacial and around two paleomagnetic reversals constrained by independent dating methods. September perihelia timing during the Pleistocene were used as a tuning target for the BDP-96 composite record. Tuning results in a robust timescale which passes spectral analysis and magnetic reversal tests with a high degree of confidence. Power spectral analysis shows a major improvement compared with previously reported Lake Baikal timescales. Significant power is now aligned into the precession index frequencies (1/(19 kyr), 1/(22 kyr), and 1/(24kyr), testifying to the success of the tuning, as well as to the presence of consistent BioSi signal in the precession band. More importantly, the SP-tuning (which manipulates the record at precession index frequencies only) confines high signal power to a narrow band at the obliquity frequency, at 1/(41 kyr). Two major spectral peaks also occur at 1/(94 kyr) and 1/(75 kyr), which only partly coincide with the predicted orbital eccentricity band (1/(128 kyr) to 1/(95 kyr)). Cross-spectral analysis further

  12. Lignin phenols in sediments of Lake Baikal, Siberia: Application to paleoenvironmental studies

    USGS Publications Warehouse

    Orem, W.H.; Colman, Steven M.; Lerch, H.E.

    1997-01-01

    Sediments from three cores obtained from distinct depositional environments in Lake Baikal, Siberia were analyzed for organic carbon, total nitrogen and lignin phenol concentration and composition. Results were used to examine changes in paleoenvironmental conditions during climatic cycles of the late Quaternary (< 125 ka). Average organic carbon, and total nitrogen concentrations, atomic C/N ratios and organic carbon accumulation rates were significantly higher in the Holocene compared with the late Pleistocene, reflecting overall warmer temperatures and increased runoff during the Holocene. A Holocene maximum in organic carbon was observed at about 6 ka, and may represent the warmest wettest period of the Holocene. At one site (Academician Ridge) pronounced late Pleistocene maxima in organic carbon and biogenic silica were observed at about 80-85 ka, probably indicative of an interstadial period with enhanced aquatic productivity. Total sedimentary lignin phenol contents were generally lower in the late Pleistocene compared to the Holocene, but with several peaks in concentration during the late Pleistocene. These late Pleistocene peaks in total sedimentary lignin content (dated at about 80, 50 and 30 ka) directly precede or occur during peaks in sedimentary biogenic silica contents. These periods likely represent relatively warm interstadial times, with increased precipitation producing the observed increase in terrestrial runoff and aquatic productivity. Lignin phenol ratios (S/V, C/V and P/V) were used to examine changes in terrestrial vegetation type resulting from changes in paleoenvironmental conditions during the late Pleistocene. A degree of caution must be used in the interpretation of these ratios with regard to vegetation sources and paleoenvironmental conditions, because of potential compositional changes in lignin resulting from biodegradation. Nevertheless, results show that long glacial periods were characterized by terrestrial vegetation composed

  13. Grey Scale Record in Lake Baikal Sediments: Climate Significance for the Last 20 ka.

    NASA Astrophysics Data System (ADS)

    Fagel, N.; Boes, X.; Piotrovska, N.

    2004-12-01

    Three sediment cores from Lake Baïkal (52°N) are investigated to evidence Northern Eurasian regional climate and environmental changes. The last 20 ka are analyzed from Kasten cores (3-4 m) and short cores (60 cm) taken in turbidite free key-sites: Vydrino Shoulder, Posolsky Bank, and Continent Ridge (EU-CONTINENT project). The age-models of the cores are based on 14C AMS datings and magnetic susceptibility correlations. From the Late Glacial Maximum (LGM) to Present, sedimentation rates range around 0,05 to 0,14 mm/yr. Thus, the standard 5 mm sampling step represent a temporal resolution of no more than 100 to 30 years. The cores material was impregnated by a new polymer technique to analyze the sediments at higher resolution from continuous thin-section cover. We present continuous grey-scale record at 20 µm resolution, measured in the undisturbed part of the sediment, i.e. outside punctual burrows. The grey-scale is visually controlled by optical microscopy, and compared with magnetic susceptibility. Due to sediment properties, the grey-scale provides a high resolution record of diatom/clay ratio. For the Holocene, the grey density record shows that the biogenic productivity (diatoms) is related to the highest values (120-150 units), whereas the lowest values (80-100 units) are related to clays mixed with iron oxides and phosphates. The grey densities show an opposite trend compared to magnetic susceptibility. Our Baikal results are compared with Siberian chronozones and with global ice core record from Greenland (GISP 2).

  14. Lidar profiling of aerosol optical properties from Paris to Lake Baikal (Siberia)

    NASA Astrophysics Data System (ADS)

    Dieudonné, E.; Chazette, P.; Marnas, F.; Totems, J.; Shang, X.

    2015-05-01

    In June 2013, a ground-based mobile lidar performed the ~10 000 km ride from Paris to Ulan-Ude, near Lake Baikal, profiling for the first time aerosol optical properties all the way from western Europe to central Siberia. The instrument was equipped with N2-Raman and depolarization channels that enabled an optical speciation of aerosols in the low and middle troposphere. The extinction-to-backscatter ratio (also called lidar ratio or LR) and particle depolarization ratio (PDR) at 355 nm have been retrieved. The LR in the lower boundary layer (300-700 m) was found to be 63 ± 17 sr on average during the campaign with a distribution slightly skewed toward higher values that peaks between 50 and 55 sr. Although the difference is small, PDR values observed in Russian cities (>2%, except after rain) are systematically higher than the ones measured in Europe (<1%), which is probably an effect of the lifting of terrigenous aerosols by traffic on roads. Biomass burning layers from grassland or/and forest fires in southern Russia exhibit LR values ranging from 65 to 107 sr and from 3 to 4% for the PDR. During the route, desert dust aerosols originating from the Caspian and Aral seas regions were characterized for the first time, with a LR (PDR) of 43 ± 14 sr (23 ± 2%) for pure dust. The lidar observations also showed that this dust event extended over 2300 km and lasted for ~6 days. Measurements from the Moderate Resolution Imaging Spectrometer (MODIS) show that our results are comparable in terms of aerosol optical thickness (between 0.05 and 0.40 at 355 nm) with the mean aerosol load encountered throughout our route.

  15. Baikal-GVD: Results, status and plans

    NASA Astrophysics Data System (ADS)

    Avrorin, A. D.; Avrorin, A. V.; Aynutdinov, V. M.; Bannash, R.; Belolaptikov, I. A.; Bogorodsky, D. Yu.; Brudanin, V. B.; Budnev, N. M.; Danilchenko, I. A.; Domogatsky, G. V.; Doroshenko, A. A.; Dyachok, A. N.; Dzhilkibaev, Zh.-A. M.; Fialkovsky, S. V.; Gafarov, A. R.; Gaponenko, O. N.; Golubkov, K. V.; Gress, T. I.; Honz, Z.; Kebkal, K. G.; Kebkal, O. G.; Konischev, K. V.; Korobchenko, A. V.; Koshechkin, A. P.; Koshel, F. K.; Kozhin, A. V.; Kulepov, V. F.; Kuleshov, D. A.; Ljashuk, V. I.; Milenin, M. B.; Mirgazov, R. A.; Osipova, E. R.; Panfilov, A. I.; Pan'kov, L. V.; Pliskovsky, E. N.; Rozanov, M. I.; Rjabov, E. V.; Shaybonov, B. A.; Sheifler, A. A.; Shelepov, M. D.; Skurihin, A. V.; Smagina, A. A.; Suvorova, O. V.; Tabolenko, V. A.; Tarashansky, B. A.; Yakovlev, S. A.; Zagorodnikov, A. V.; Zurbanov, V. L.

    2016-04-01

    The future next-generation neutrino telescope Baikal-GVD will be a km3-scale array aimed at the detection of astrophysical neutrino fluxes. It will have modular structure and consist of functionally independent sub-arrays - clusters of strings of optical modules. The prototyping phase of the project has been concluded in 2015 with the deployment of the first cluster of Baikal-GVD in Lake Baikal. We discuss the current status and perspectives of the Baikal-GVD project.

  16. Evaluation of biochemical responses in Palearctic and Lake Baikal endemic amphipod species exposed to CdCl2.

    PubMed

    Timofeyev, M A; Shatilina, Z M; Bedulina, D S; Protopopova, M V; Pavlichenko, V V; Grabelnych, O I; Kolesnichenko, A V

    2008-05-01

    This study evaluated small heat shock proteins (sHSP) (related to alpha-crystallin) and antioxidant enzymes (POD, peroxidase and CAT, catalase) as possible biomarkers for use in toxicological studies. Biochemical responses to cadmium chloride in two Lake Baikal endemic amphipods (Eulimnogammarus verrucosus, Eulimnogammarus cyaneus) and Palearctic species (Gammarus lacustris) were compared. Our findings showed that cadmium chloride toxicity directly influenced POD activity and sHSP synthesis in all amphipod species. The Baikalean endemic and the Palearctic amphipod species responded by decreasing activity of POD and they exhibited a dose-dependent activation of sHSP synthesis. All measured parameters differed among species and depended on the species' ability to resist cadmium chloride toxicity. CAT activity in the Palearctic species responded significantly to cadmium chloride exposure; however, responses were negligible for both Baikalean species. We suggest that synthesis of sHSP, together with changes in POD activity, could be used as biomarkers for further studies of amphipod species including endemics from Lake Baikal. PMID:17920682

  17. Bacterial community composition in the water column of the deepest freshwater Lake Baikal as determined by next-generation sequencing.

    PubMed

    Kurilkina, Maria I; Zakharova, Yulia R; Galachyants, Yuri P; Petrova, Darya P; Bukin, Yuri S; Domysheva, Valentina M; Blinov, Vadim V; Likhoshway, Yelena V

    2016-07-01

    The composition of bacterial communities in Lake Baikal in different hydrological periods and at different depths (down to 1515 m) has been analyzed using pyrosequencing of the 16S rRNA gene V3 variable region. Most of the resulting 34 562 reads of the Bacteria domain have clustered into 1693 operational taxonomic units (OTUs) classified with the phyla Proteobacteria, Actinobacteria, Chloroflexi, Bacteroidetes, Firmicutes, Acidobacteria and Cyanobacteria. It has been found that their composition at the family level and relative contributions to bacterial communities distributed over the water column vary depending on hydrological period. The number of OTUs and the parameters of taxonomic richness (ACE, Chao1 indices) and diversity (Shannon and inverse Simpson index) reach the highest values in water layers. The composition of bacterial communities in these layers remains relatively constant, whereas that in surface layers differs between hydrological seasons. The dynamics of physicochemical conditions over the water column and their relative constancy in deep layers are decisive factors in shaping the pattern of bacterial communities in Lake Baikal. PMID:27162182

  18. [Detection of methane in the water column at gas and oil seep sites in central and southern Lake Baikal].

    PubMed

    Zakharenko, A S; Pimenov, N V; Ivanov, V G; Zemskaia, T I

    2015-01-01

    Microbiological and biogeochemical investigation of the water column of oligotrophic Lake Baikal at the sites of the K2 and Bolshoy mud volcanoes and the Gorevoy Utes oil seep was carried out in July 2013. Total microbial numbers (TMN), cell numbers of type I and type II methanotrophs, and methane concentrations were measured; the rate of methane oxidation was determined. Methane concentrations in Lake Baikal water column varied from 0.09 to 1 μL/L, while methane oxidation rates varied from 0.007 to 0.9 nL/(L day). The highest rates of methane oxidation were revealed in the near-bottom water horizons at the sites of the Bolshoy mud volcano and the Gorevoy Utes oil seep. These were the sites where the most pronounced anomalies in methane concentration were also detected. TMN varied from 0.123 x 10(6) to 1.64 x 10(6) cells/mL. Methanotrophic bacteria were revealed in the water column at all sites, their abundance did not always correlate with methane concentrationsand the rates of methane oxidation. Methanotrophs constituted not more than 1.63% of the total microbial number, with their highest abundance in the upper 200 m of the water column. PMID:25916152

  19. Spectral tuning and molecular evolution of rod visual pigments in the species flock of cottoid fish in Lake Baikal.

    PubMed

    Hunt, D M; Fitzgibbon, J; Slobodyanyuk, S J; Bowmaker, J K

    1996-05-01

    Lake Baikal in Eastern Siberia is the deepest and one of the largest and most ancient lakes in the world. However, even in the deepest regions, oxygenation levels do not fall below 75-80% of the surface levels. This has enabled a remarkable flock of largely endemic teleost fish of the sub-order Cottoidei to colonize all depth habitats. We have previously shown that species that occupy progressively deeper habitats show a blue shift in the peak wavelength of absorbance (lambda max) of both their rod and cone visual pigments; for the rod pigments, a number of stepwise shifts occur from about 516 nm in littoral species to about 484 nm in abyssal species. By sequencing the rod opsin gene from 11 species of Baikal cottoids that include representatives from all depth habitats, we have been able to identify four amino acid substitutions that would account for these shifts. The effect of each substitution on lambda max is approximately additive and each corresponds to a particular lineage of evolution. PMID:8711901

  20. Falling phytoplankton: altered access to the photic zone over 60 years of warming in Lake Baikal, Siberia

    NASA Astrophysics Data System (ADS)

    Hampton, S. E.; Izmest'eva, L. R.; Moore, M.; Katz, S. L.

    2011-12-01

    Vertical stratification of aquatic ecosystems can be strongly reinforced by long-term warming, altering access to suitable habitat differentially across plankton taxa. Surface waters in the world's most voluminous freshwater lake - Lake Baikal in Siberia - are warming at an average rate of 2.01°C century-1, with more dramatic warming in the summer (3.78°C century-1). This long-term warming trend occurs within seasonal cycles of freezing and thawing, and against the larger backdrop of shorter-term climate dynamics, such as those associated with the Pacific Decadal Oscillation and Arctic Oscillation, with which shifting Siberian weather patterns affect the timing of seasonal changes (e.g., stratification) at the lake. While the increasing temperature difference between surface and deeper waters implies stronger stratification in the summer in general, the available long-term temperature data are not sufficiently fine-scaled across depth to further resolve stratification patterns. However, analysis of long-term vertical phytoplankton distributions may give perspectives on the dynamics of the physical environment that plankton experience. For example, many of Lake Baikal's endemic, cold-adapted phytoplankton species are large and heavy diatoms that require strong mixing to remain suspended, a process that is suppressed by stronger summer stratification. Observed vertical patterns of algal distribution are consistent with the predictions of increased warming and intensified stratification with diatoms present in summer increasingly sinking far beyond the photic zone. Specifically, the average depth of diatoms in August, the most reliably stratified month at Lake Baikal, has increased from depths roughly aligned with photic zone (0.1% light penetration) limits (ca. 40 m) in the 1970s to average depths approximately 48 m below the photic zone by the end of the century. Concurrently, smaller motile algae such as cryptomonads have maintained or increased their presence in

  1. Vertical stability and the Brunt-Väisäla frequency of deep natural waters by the example of Lake Baikal, Lake Tanganyika, and the World Ocean

    NASA Astrophysics Data System (ADS)

    Sherstyankin, P. P.; Kuimova, L. N.

    2009-12-01

    Theoretical analysis, calculations, and comparison with the results of observations in Lake Baikal, Lake Tanganyika, and the World Ocean are performed for the vertical stability E and the Brunt-Väisäla frequency N in the form of N 2 with regard to all components (at the constant temperature T and the salinity S, the common adiabatic form at T, S Const). The adiabatic stability E ad and the Väisäla frequency N in the form of N {/ad 2} are always positive; at a change from the inverse to the direct temperature stratification, they have deep minimums reaching 10-16 m-1 and 10-15 s-2 and less; the minimums have the form of a special point, a reversal point of the first kind called a “cusp.” The reality of these reversal points is confirmed by the analysis of the investigation procedure, comparison with the results of previous theoretical (Sherstyankin, et al., 2007), and experimental (observations in Baikal, Shimaraev et al., 1994) works. The features of vertical profiles of E ad , E and N {/ad 2}, N 2, as well as the layers where the Brunt-Väisäla frequency is less than the inertial frequency, are studied. The analysis with regard to all components of the stability E ad and the Brunt-Väisäla frequency N makes a great contribution to understanding of mixing processes in theoretical and experimental investigations; it is valid in all reservoirs of the Earth with inverse and direct temperature stratification, including Lake Baikal, Lake Tanganyika, and the World Ocean.

  2. The effect of bloom of filamentous green algae on the reproduction of yellowfin sculpin Cottocomephorus grewingkii (Dybowski, 1874) (Cottoidae) during ecological crisis in Lake Baikal.

    PubMed

    Khanaev, I V; Dzyuba, E V; Kravtsova, L S; Grachev, M A

    2016-03-01

    In shallow water areas of open Lake Baikal, filamentous green alga of the genus Spirogyra grows abundantly. Together with alga of the genus Ulothrix, it forms algal mats. According to our observations from 2010 to 2013, the spawning habitat conditions for the yellowfin sculpin Cottocomephorus grewingkii (Dybowski, 1874) (Cottidae) proved to be significantly disturbed in the littoral zone of Listvennichnyi Bay (southern Baikal), which, in turn, reduced the number of egg layings. With a 100% projective cover of the floor and a high density of green filamentous algae, the shallow-water stony substrate becomes completely inaccessible for spawning of the August population. PMID:27193877

  3. ESR signals in a core from the lake Baikal: implications for climate change

    NASA Astrophysics Data System (ADS)

    Toyoda, S.; Hidaka, K.; Takamatsu, N.

    2002-12-01

    Electron spin resonance dating method has been used for obtaining ages of Quaternary events using speleothem, corals, shells, hydroxyapatite in tooth enamel, gypsum, and quartz (Ikeya, 1993). Recently, it was also found that an ESR signal in quartz of loess is useful to discuss the variation of its origin (e. g. Ono et al., 1998). The method is based on the signal intensity of the heat treated (gamma ray irradiation and heating, Toyoda and Ikeya, 1991) E 1_f center (an unpaired electron at an oxygen vacancy) correlates the original (crystallization) age of quartz (e.g. Toyoda and Hattori, 2000). If there is variation in ages of basement rocks (origin of loess), ESR signal intensity may differentiate the origins. We applied the present method to sediments taken from the core of the lake Baikal with the length of 600m. The ESR intensity of the heat treated E1_f center was determined by an ESR measurement at room temperature for about 100 mg of the bulk samples, with a microwave power of 0.01 mW, field modulation amplitude of 0.1 mT, and with a scan range of 5 mT around g=2.001 after gamma ray irradiation to 1 kGy and subsequent heating at 300C. The ESR signal of the E1_f center was clearly observed although other minerals are also included in the bulk sample. The peak to peak height was taken as the signal intensity after normalizing the height with the gain (the instrumental setting at the time of measurement), mass, and the intensity of the standard simultaneously measured with the sample. The concentrations of the quartz in the bulk samples were obtained by the X ray diffraction study, normalizing the peak intensity with a standard CeO sample. The variation of the ESR signal intensity with depth of the core will be presented together with the possible climate change which may have caused the variation. References M. Ikeya (1993) New applications of electron spin resonance, dating, dosimetry and imaging, World Scientific. Y. Ono, T. Naruse, M. Ikeya, H. Kohno, and

  4. Formation of ferric iron crusts in Quaternary sediments of Lake Baikal, Russia, and implications for paleoclimate

    USGS Publications Warehouse

    Deike, R.G.; Granina, L.; Callender, E.; McGee, J.J.

    1997-01-01

    Phosphate-bearing, ferric iron and siliceous crusts ranging in age from Recent to approximately 65,000 yr B.P. are observed in sediments of Lake Baikal. In younger sediments the crusts are at the base of a spectrum of secondary iron and manganese oxides that accumulate near the sediment/water interface in the zone of positive oxidation potential beneath an oxygenated water column. In areas where the average Quaternary sedimentation rates have been slow (e.g. 0.026 mm/yr), the crusts are more common, and span a wider range of ages. No crusts have been found where the Quaternary sedimentation mode has been deltaic and rapid (0.15 mm/yr). Independent core correlation based on magnetic properties of the sediment suggests that crusts can be correlated over most of Academician Ridge, an area that is particularly sensitive to climatic events affecting the concentration of suspended sediment. These crusts may be indicative of periods of low suspended sediment concentration, which occur during sustained transitions from glacial periods of high detrital input, to interglacial periods of high diatom sedimentation. The crusts are dominated by iron-rich and siliceous amorphous mineral phases, with an FeO:SiO2 by weight of 3:1. Regardless of age or location in the lake the Fe phase always includes Ca, P and Mn. Extensive microprobe data for these four elements recast as normalized elemental weight percent reveal linear trends of Ca:P and Fe:P. With increasing P, Ca also increases such that the two elements maintain a linear relationship passing very close to the origin and with a mean molar Ca:P=0.3 (too low for well-characterized apatite). Conversely, with increasing P, Fe decreases (mean molar Fe:P=3.4). There is no correlation between Mn and P. Molar Fe:P ratios for vivianite (an Fe(II) phosphate mineral observed in sediments closely below some crusts) are clustered around a stoichiometric composition. The covariant increase in Ca:P and the corresponding decrease in Fe:P may

  5. Biogenic silica records from the BDP93 drill site and adjacent areas of the Selenga Delta, Lake Baikal, Siberia

    USGS Publications Warehouse

    Colman, Steven M.; Peck, J.A.; Hatton, J.; Karabanov, E.B.; King, J.W.

    1999-01-01

    Biogenic silica contents of sediments on the lower Selenga Delta and Buguldeika saddle in Lake Baikal show distinct fluctuations that reflect changes in diatom productivity, and ultimately, climate. The pattern of the upper 50 m of the section, dating from about 334 ka, is similar to that of the marine oxygen-isotope record, increasingly so as the younger sediments become progressively finer grained and less locally derived with time. The last two interglaciations are marked by biogenic silica abundances similar to those of the Holocene. The equivalent of marine oxygen-isotope stage 3 is distinctly intermediate in character between full glacial and full interglacial biogenic silica values. Following near-zero values during the last glacial maximum, biogenic silica began to increase at about 13 ka. The rise in biogenic silica to Holocene values was interrupted by an abrupt decrease during Younger Dryas time, about 11 to 10 14C ka.

  6. The centuries-old and thousand- year oscillations of uranium distribution in the Lake Baikal sediments, according to the neutron-fission (n,f)-autoradiography

    NASA Astrophysics Data System (ADS)

    Kirichenko, Ivan; Zhmodik, Sergey; Belyanin, Dmitriy; Khlistov, Oleg

    2016-04-01

    The trace elements local distribution data, particularly (U, P, Br, Mo, BiSi et. all) in a lake and oceans bottom sediments reflects the conditions of those sediments formation, and correlates with changes in paleoclimatic conditions. In papers [Colman et all, 1995; Goldberg et all, 2000, etc.] established that the concentrations of some elements contained in the bottom sediments of Lake Baikal, in particular BiSi, Sr / Ba, Sr / Rb, Ti, U et al., reflect changes in insolation caused by periodic oscillations parameters Earth's orbit (Milankovitch cycles). At the same time, a bottom sediments of the largest continental lake (Lake Baikal), can keep a record of changes less periodicity. Our research focuses on the study of the spatial distribution of uranium with high resolution in the bottom sediments of Lake Baikal. The purpose of this research is determination the centure-old and thousand- old year oscillations in the concentration of uranium in the sediments of Lake Baikal. Fragments of the lake sediment columns taken from the axial part of the Akademicheskiy Ridge in Lake Baikal (stations coordinates St -8 (53 32'15"N 107 56'25"E); - and St11 - (53 33'51"N 108 00'05"E) were studied using complex of local analysis methods, such as: n, f - and n, β-autoradiography, SEM. The distributions of uranium and phosphorus in the authigenic component of sediments along the whole columns length (with the resolution of 10 micron which corresponds to the time resolution of about six months) have been studied by the autoradiography method. Statistical data analysis (Fourier and wavelet analysis) were used for detection oscillations in the uranium concentration Three main different factors of concentrators were established for uranium and phosphorus in the sediments of the Academic mountain range:1) sedimentation, 2) nutrient,3) diagenetic. The periodicity (range from 100 to 1,000 years), in the distribution of authigenic uranium in the sediment column were identified by

  7. The optical module of Baikal-GVD

    NASA Astrophysics Data System (ADS)

    Avrorin, A. D.; Avrorin, A. V.; Aynutdinov, V. M.; Bannash, R.; Belolaptikov, I. A.; Bogorodsky, D. Yu.; Brudanin, V. B.; Budnev, N. M.; Danilchenko, I. A.; Domogatsky, G. V.; Doroshenko, A. A.; Dyachok, A. N.; Dzhilkibaev, Zh.-A. M.; Fialkovsky, S. V.; Gafarov, A. R.; Gaponenko, O. N.; Golubkov, K. V.; Gress, T. I.; Honz, Z.; Kebkal, K. G.; Kebkal, O. G.; Konischev, K. V.; Korobchenko, A. V.; Koshechkin, A. P.; Koshel, F. K.; Kozhin, A. V.; Kulepov, V. F.; Kuleshov, D. A.; Ljashuk, V. I.; Milenin, M. B.; Mirgazov, R. A.; Osipova, E. R.; Panfilov, A. I.; Pan'kov, L. V.; Pliskovsky, E. N.; Rozanov, M. I.; Rjabov, E. V.; Shaybonov, B. A.; Sheifler, A. A.; Shelepov, M. D.; Skurihin, A. V.; Smagina, A. A.; Suvorova, O. V.; Tabolenko, V. A.; Tarashansky, B. A.; Yakovlev, S. A.; Zagorodnikov, A. V.; Zhukov, V. A.; Zurbanov, V. L.

    2016-04-01

    The Baikal-GVD neutrino telescope in Lake Baikal is intended for studying astrophysical neutrino fluxes by recording the Cherenkov radiation of the secondary muons and showers generated in neutrino interactions. The first stage of Baikal-GVD will be equipped with about 2300 optical modules. We describe the design of the optical module, the front-end electronics and the laboratory characterization and calibration before deployment.

  8. Assessment of diffuse heavy metal pollution, mass transfer and flows at a gold mining site within the Lake Baikal Basin

    NASA Astrophysics Data System (ADS)

    Thorslund, Josefin; Jarsjö, Jerker; Chalov, Sergey; Belozerova, Ekaterina

    2013-04-01

    The flux, transfer and accumulation of heavy metals in aquatic systems pose a potential danger to the ecosystem at various scales, due to their toxicity and non-destroyable nature. Mining and ore excavation can cause heavy metal pollution of both local and downstream water systems, including groundwater sources. The Zaamar Goldfield, located in the upper Lake Baikal Basin (Mongolia), is an example of an extensive gold mining site, which significantly contributes to downstream increases in riverine concentrations of heavy metals, both in dissolved and suspended phases. However, the placer mining area is large and the pollution is diffuse by nature. Due to lack of detailed monitoring, it is unclear how the pollution is transported from the mine tailings to the river. There are several potentially important pathways, such as mobilization of bank sediments, in-stream dissolution from metal-rich suspended/bottom sediments, and through polluted groundwater. We here aim at estimating diffuse mass flows from the source zone to the river, in addition to riverine mass flows. Additionally, the behaviour of heavy metals under varying geochemical conditions (such as pH) is investigated, to be able to understand the solubility of various heavy metals and their partitioning between particulate and dissolved phase. We base our analysis on on-site hydrogeochemical field campaigns. These include concentration measurements in different media (groundwater, waste ponds, ditches, river water, suspended sediments, and bottom sediments). Runoff estimations from the site as well as solubility calculations are also main analytical methods. Results show a net increase in both dissolved and suspended riverine mass flows over the Zaamar site. Concentrations in the deep groundwater system are generally in the same order of magnitude as river concentrations, which suggest important inputs of dissolved heavy metals to the river through groundwater flows. The input of dissolved concentrations are

  9. Different magnetostratigraphic approaches: Lake Baikal sediments and the J/K boundary strata in the Tethyan realm

    NASA Astrophysics Data System (ADS)

    Pruner, P.; Housa, V.; Kadlec, J.; Chadima, M.; Schnabl, P.; Slechta, S.

    2004-12-01

    Rock magnetic and paleomagnetic parameters were studied on two cores drilled in the Academician Ridge, Lake Baikal, Russia. The rock magnetic parameters were used to identify variations in the concentration, grain size and mineralogy of the magnetic material. Three intervals of deviating declinations and inclinations with steep totally reversed inclinations are clearly present in the cores. The ChRM directions were clearly dominated by normal polarity indicating the Brunhes Chron age of the sediments. The observed excursions were interpreted as the Blake excursion, the Iceland Basin excursion and the Biwa II excursion. The reversal excursions fall within the intensity minima. On the basis of the identification of excursions we correlated the magnetostratigraphic results (relative paleointensity and polarity) from the Lake Baikal sediments to comparable data sets from ODP site 984. Data obtained from the cores indicate the age of deposits up to 300 ka. Comparing the variations of the paleointensity records the mean sedimentation rate in the range of 3 - 4 cm/ka can be estimated. The result of magnetostratigraphic and micropalaeontological investigations of the Jurassic/Cretaceous boundary strata in the Tethyan realm (Brodno - Slovakia, the Bosso Valley - Italy, and Puerto Escano - Spain) can be reasonably intercorrelated. Reverse subzones proposed to be named "Kysuca Subzone" in M20n and "Brodno Subzone" in M19n were precisely localized in all studied profiles. All the magnetozones and subzones can be related to the M-sequence of marine magnetic anomalies. At the locality of Brodno, the interpreted duration of the transition between N - R (R - N) polarity falls into the range of 5 - 10 ka. Stratigraphically significant calpionellid events occupy an identical position in relation to magnetozones and subzones derived in all the three sections. The base of the calpionellid zone Crassicolaria coincides with the base of the "Kysuca Subzone". Appearance of the species

  10. Specific antioxidant reactions to oxidative stress promoted by natural organic matter in two amphipod species from Lake Baikal.

    PubMed

    Timofeyev, Maxim A; Shatilina, Zhanna M; Kolesnichenko, Aleksey V; Kolesnichenko, Viktoria V; Steinberg, Christian E W

    2006-04-01

    Aquatic organisms are exposed to a variety of natural chemical stressors such as humic substances. The aim of this study was to investigate the mode of action of natural organic matter (NOM, roughly 80% of which is humic substances) on two freshwater amphipods from Lake Baikal, Eulimnogammarus verrucosus (Gerstf.) and Eulimnogammarus cyaneus (Dyb.), in order to assess the potential oxidative stress of NOM impact. Chosen as oxidative stress markers were lipid peroxidation and cell internal hydrogen peroxide level as well as peroxidase, catalase, and glutathione S-transferase activities. Exposure of amphipods to NOM caused a significant increase in lipid peroxidation but a concomitant decrease in hydrogen peroxide concentration, and peroxidase and (to a lesser degree) glutathione S-transferase activities. An interim increase of catalase activity was observed. A possible reason for the decrease in major antioxidant enzyme activity is exhaustion of the reservoir of reduced substrates in the first stage of the antioxidant defense reaction. Despite the inhibition of major antioxidant enzymes, the studied amphipods were able to successfully resist the NOM oxidative impact and, at low NOM concentrations, to combat lipid peroxidation processes. PMID:16528684

  11. Unified Scaling Law for Earthquakes: Seismic hazard and risk assessment for Himalayas, Lake Baikal, and Central China regions

    NASA Astrophysics Data System (ADS)

    Nekrasova, Anastasia; Kossobokov, Vladimir; Parvez, Imtiyaz; Tao, Xiaxin

    2015-04-01

    The Unified Scaling Law for Earthquakes (USLE), that generalizes the Gutenberg-Richter recurrence relation, has evident implications since any estimate of seismic hazard depends on the size of the territory that is used for investigation, averaging, and extrapolation into the future. Therefore, the hazard may differ dramatically when scaled down to the proportion of the area of interest (e.g. territory occupied by a city) from the enveloping area of investigation. In fact, given the observed patterns of distributed seismic activity the results of multi-scale analysis embedded in USLE approach demonstrate that traditional estimations of seismic hazard and risks for cities and urban agglomerations are usually underestimated. Moreover, the USLE approach provides a significant improvement when compared to the results of probabilistic seismic hazard analysis, e.g. the maps resulted from the Global Seismic Hazard Assessment Project (GSHAP). We apply the USLE approach to evaluating seismic hazard and risks to population of the three territories of different size representing a sub-continental and two different regional scales of analysis, i.e. the Himalayas and surroundings, Lake Baikal, and Central China regions.

  12. Rift flank segmentation, basin initiation and propagation: a neotectonic example from Lake Baikal

    USGS Publications Warehouse

    Agar, S.M.; Klitgord, Kim D.

    1995-01-01

    New surficial data (field, Landsat TM and topography) define morpho-tectonic domains and rift flank segmentation in the Ol'khon region of the Central Baikal rift. Deformation, drainage and depositional patterns indicate a change in the locus of active extension that may relate to a recent (

  13. Analysis of Lake Baikal's phytoplankton and fluvial input dynamics using SeaWiFS satellite data within the Scope of the Paleoclimate Project CONTINENT

    NASA Astrophysics Data System (ADS)

    Heim, B.; Oberhaensli, H.; Kaufmann, H.

    2003-04-01

    Multispectral ocean colour satellite data provide a new tool for spatial and temporal limnological data overview. The Ulaan Baatar (Mongolia) HRPT (high resolution picture transmission) station provides the paleoclimate EC-Project CONTINENT "High Resolution CONTINENTal Paleoclimate Record in Lake Baikal (Siberia, Russia)" with daily SeaWiFS data covering the area of south-eastern Siberia. After a SeaWiFS data processing chain with radiometric and atmospheric correction, we use the water leaving reflectances to gain information on phytoplankton and suspended sediment whose dynamics are a response to the present climate forcing. During the CONTINENT Summer cruises in 2001 and 2002, we were able to verify the spectral analysis of SeaWiFS satellite data with a high quality calibration/validation ground truth data set (field spectrometer and fluorometer measurement activities simultaneously to water sampling activities for pigment and suspended matter SPM and DOC analysis and algae counting). The fluviatil input into Lake Baikal is visible in the SeaWiFS data due to its higher loads of suspended matter, further particularly due to the presence of coloured dissolved organic matter (cDOM). These coloured fraction of DOM (mainly humic acids) originate from the bog areas and swampy basins within the Lake Baikal watershed. The so called yellow substances react optically with a strong absorption in the blue spectral bands of SeaWiFS and are therefore ideal tracers for the river input even over long distances from the river inflow. The phytoplankton main pigment chlorophyll-a is made visible by its absorption band in the blue which results in a green reflectance peak. Additional pigment groups (carotinoids, phycobilins) differentiate the spectral shape of the water leaving reflectance depending on the respective main phytoplankton composition. On satellite images obtained in late Summer, we can differentiate between diatom and cyanobacteria-picoplankton dominated surface water

  14. Heat and mass transfer effects during displacement of deepwater methane hydrate to the surface of Lake Baikal

    NASA Astrophysics Data System (ADS)

    Egorov, Alexander V.; Nigmatulin, Robert I.; Rozhkov, Aleksey N.

    2016-06-01

    The present paper focuses on heat and mass exchange processes in methane hydrate fragments during in situ displacement from the gas hydrate stability zone (GHSZ) to the water surface of Lake Baikal. After being extracted from the methane hydrate deposit at the lakebed, hydrate fragments were placed into a container with transparent walls and a bottom grid. There were no changes in the hydrate fragments during ascent within the GHSZ. The water temperature in the container remained the same as that of the ambient water (~3.5 °C). However, as soon as the container crossed the upper border of the GHSZ, first signs of hydrate decomposition and transformation into free methane gas were observed. The gas filled the container and displaced water from it. At 300 m depth, the upper and lower thermometers in the container simultaneously recorded noticeable decreases of temperature. The temperature in the upper part of the container decreased to -0.25 °C at about 200 m depth, after which the temperature remained constant until the water surface was reached. The temperature at the bottom of the container reached -0.25 °C at about 100 m depth, after which it did not vary during further ascent. These observed effects could be explained by the formation of a gas phase in the container and an ice layer on the hydrate surface caused by heat consumption during hydrate decomposition (self-preservation effect). However, steady-state simulations suggest that the forming ice layer is too thin to sustain the hydrate internal pressure required to protect the hydrate from decomposition. Thus, the mechanism of self-preservation remains unclear.

  15. The Structure of Microbial Community and Degradation of Diatoms in the Deep Near-Bottom Layer of Lake Baikal

    PubMed Central

    Zakharova, Yulia R.; Galachyants, Yuri P.; Kurilkina, Maria I.; Likhoshvay, Alexander V.; Petrova, Darya P.; Shishlyannikov, Sergey M.; Ravin, Nikolai V.; Mardanov, Andrey V.; Beletsky, Alexey V.; Likhoshway, Yelena V.

    2013-01-01

    Insight into the role of bacteria in degradation of diatoms is important for understanding the factors and components of silica turnover in aquatic ecosystems. Using microscopic methods, it has been shown that the degree of diatom preservation and the numbers of diatom-associated bacteria in the surface layer of bottom sediments decrease with depth; in the near-bottom water layer, the majority of bacteria are associated with diatom cells, being located either on the cell surface or within the cell. The structure of microbial community in the near-bottom water layer has been characterized by pyrosequencing of the 16S rRNA gene, which has revealed 149 208 unique sequences. According to the results of metagenomic analysis, the community is dominated by representatives of Proteobacteria (41.9%), Actinobacteria (16%); then follow Acidobacteria (6.9%), Cyanobacteria (5%), Bacteroidetes (4.7%), Firmicutes (2.8%), Nitrospira (1.6%), and Verrucomicrobia (1%); other phylotypes account for less than 1% each. For 18.7% of the sequences, taxonomic identification has been possible only to the Bacteria domain level. Many bacteria identified to the genus level have close relatives occurring in other aquatic ecosystems and soils. The metagenome of the bacterial community from the near-bottom water layer also contains 16S rRNA gene sequences found in previously isolated bacterial strains possessing hydrolytic enzyme activity. These data show that potential degraders of diatoms occur among the vast variety of microorganisms in the near-bottom water of Lake Baikal. PMID:23560063

  16. Molecular and isotopic composition of hydrate-bound and dissolved gases in the southern basin of Lake Baikal, based on an improved headspace gas method

    NASA Astrophysics Data System (ADS)

    Sakagami, Hirotoshi; Takahashi, Nobuo; Hachikubo, Akihiro; Minami, Hirotsugu; Yamashita, Satoshi; Shoji, Hitoshi; Khlystov, Oleg; Kalmychkov, Gennadiy; Grachev, Mikhail; De Batist, Marc

    2012-12-01

    Assessments of the molecular and isotopic composition of hydrate-bound and dissolved gases in pore water were conducted during the multi-phase gas hydrate project (MHP-09) cruise VER09-03 to the southern basin of Lake Baikal in September 2009. To avoid changes in gas composition during core sampling and transport, various headspace methods were investigated aimed at preserving the dissolved gases in pore water. When distilled water was added to the sediment samples, the concentrations of carbon dioxide and oxygen decreased because of dissolution into the water and/or microbial consumption. When the headspace was not flushed with inert gases, trace levels of hydrogen and ethylene were detected. The findings suggest that best preparation is achieved by flushing the headspace with helium, and adding a saturated aqueous solution of sodium chloride. This improved headspace method served to examine the molecular and isotopic compositions of gas samples retrieved at several new sites in the southern basin. Methane was the major component, and the proportion of ethane ranged widely from 0.0009 to 1.67 mol% of the total hydrocarbon gases. The proportions of propane and higher hydrocarbons were small or less than their detection limits. The carbon isotope signatures suggest that microbial-sourced methane and ethane were dominant in the Peschanka study area, whereas ethane was of thermogenic origin at all other study sites in the southern basin of Lake Baikal.

  17. Active faults of the Baikal depression

    USGS Publications Warehouse

    Levi, K.G.; Miroshnichenko, A.I.; San'kov, V. A.; Babushkin, S.M.; Larkin, G.V.; Badardinov, A.A.; Wong, H.K.; Colman, S.; Delvaux, D.

    1997-01-01

    The Baikal depression occupies a central position in the system of the basins of the Baikal Rift Zone and corresponds to the nucleus from which the continental lithosphere began to open. For different reasons, the internal structure of the Lake Baikal basin remained unknown for a long time. In this article, we present for the first time a synthesis of the data concerning the structure of the sedimentary section beneath Lake Baikal, which were obtained by complex seismic and structural investigations, conducted mainly from 1989 to 1992. We make a brief description of the most interesting seismic profiles which provide a rough idea of a sedimentary unit structure, present a detailed structural interpretation and show the relationship between active faults in the lake, heat flow anomalies and recent hydrothermalism.

  18. Quantitative reconstruction of the last interglacial vegetation and climate based on the pollen record from Lake Baikal, Russia

    NASA Astrophysics Data System (ADS)

    Tarasov, P.; Granoszewski, W.; Bezrukova, E.; Brewer, S.; Nita, M.; Abzaeva, A.; Oberhänsli, H.

    2005-11-01

    Changes in mean temperature of the coldest ( T c) and warmest month ( T w), annual precipitation ( P ann) and moisture index (α) were reconstructed from a continuous pollen record from Lake Baikal, Russia. The pollen sequence CON01-603-2 (53°57'N, 108°54'E) was recovered from a 386 m water depth in the Continent Ridge and dated to ca. 130 114.8 ky BP. This time interval covers the complete last interglacial (LI), corresponding to MIS 5e. Results of pollen analysis and pollen-based quantitative biome reconstruction show pronounced changes in the regional vegetation throughout the record. Shrubby tundra covered the area at the beginning of MIS 5e (ca. 130 128 ky), consistent with the end of the Middle Pleistocene glaciation. The late glacial climate was characterised by low winter and summer temperatures ( T c ~ -38 to -35°C and T w~11 13°C) and low annual precipitation ( P ann~300 mm). However, the wide spread of tundra vegetation suggests rather moist environments associated with low temperatures and evaporation (reconstructed α~1). Tundra was replaced by boreal conifer forest (taiga) by ca. 128 ky BP, suggesting a transition to the interglacial. Taiga-dominant phase lasted until ca. 117.4 ky BP, e.g. about 10 ky. The most favourable climate conditions occurred during the first half of the LI. P ann reached 500 mm soon after 128 ky BP. However, temperature changed more gradually. Maximum values of T c ~ -20°C and T w~16 17°C are reconstructed from about 126 ky BP. Conditions became gradually colder after ca. 121 ky BP. T c dropped to ~ -27°C and T w to ~15°C by 119.5 ky BP. The reconstructed increase in continentality was accompanied by a decrease in P ann to ~400 420 mm. However, the climate was still humid enough (α~0.9) to support growth of boreal evergreen conifers. A sharp turn towards a dry climate is reconstructed after ca. 118 ky BP, causing retreat of forest and spread of cool grass-shrub communities. Cool steppe dominated the vegetation in the

  19. Linking the10Be continental record of Lake Baikal to marine and ice archives of the last 50 ka: Implication for the global dust-aerosol input

    USGS Publications Warehouse

    Aldahan, A.; Possnert, G.; Peck, J.; King, J.; Colman, S.

    1999-01-01

    We present here a 10Be profile from the continental sediments of Lake Baikal (the world's largest fresh water lake), which, for the first time, shows the ??? 40 ka 10Be enhancement and a pattern that strongly matches those from the marine and ice records for the last 50 ka. This finding provides a new horizon for global and regional correlation of continental archives. Additionally, our VADM-predicted 10Be production confirms and further strengthens a common global cause (geomagnetic field intensity) for the change in atmospheric 10Be over the last 50 ka. We also show that most of the 10Be inventory to the lake has been provided by riverine input, but with a significant addition from direct precipitation and dust-aerosol fallout. We estimate a higher dust-aerosol contribution of 10Be during the Holocene and interstadial stage 3 (22-50 ka) as compared with the glacial period (12-22 ka). Copyright 1999 by the American Geophysical Union.

  20. The Ability of Microbial Community of Lake Baikal Bottom Sediments Associated with Gas Discharge to Carry Out the Transformation of Organic Matter under Thermobaric Conditions

    PubMed Central

    Bukin, Sergei V.; Pavlova, Olga N.; Manakov, Andrei Y.; Kostyreva, Elena A.; Chernitsyna, Svetlana M.; Mamaeva, Elena V.; Pogodaeva, Tatyana V.; Zemskaya, Tamara I.

    2016-01-01

    The ability to compare the composition and metabolic potential of microbial communities inhabiting the subsurface sediment in geographically distinct locations is one of the keys to understanding the evolution and function of the subsurface biosphere. Prospective areas for study of the subsurface biosphere are the sites of hydrocarbon discharges on the bottom of the Lake Baikal rift, where ascending fluxes of gas-saturated fluids and oil from deep layers of bottom sediments seep into near-surface sediment. The samples of surface sediments collected in the area of the Posolskaya Bank methane seep were cultured for 17 months under thermobaric conditions (80°C, 5 MPa) with the addition of complementary organic substrate, and a different composition for the gas phase. After incubation, the presence of intact cells of microorganisms, organic matter transformation and the formation of oil biomarkers was confirmed in the samples, with the addition of Baikal diatom alga Synedra acus detritus, and gas mixture CH4:H2:CO2. Taxonomic assignment of the 16S rRNA sequence data indicates that the predominant sequences in the enrichment were Sphingomonas (55.3%), Solirubrobacter (27.5%) and Arthrobacter (16.6%). At the same time, in heat-killed sediment and in sediment without any additional substrates, which were cultivated in a CH4 atmosphere, no geochemical changes were detected, nor the presence of intact cells and 16S rRNA sequences of Bacteria and Archaea. This data may suggest that the decomposition of organic matter under culturing conditions could be performed by microorganisms from low-temperature sediment layers. One possible explanation of this phenomenon is migration of the representatives of the deep thermophilic community through fault zones in the near surface sediment layers, together with gas-bearing fluids. PMID:27242716

  1. The Ability of Microbial Community of Lake Baikal Bottom Sediments Associated with Gas Discharge to Carry Out the Transformation of Organic Matter under Thermobaric Conditions.

    PubMed

    Bukin, Sergei V; Pavlova, Olga N; Manakov, Andrei Y; Kostyreva, Elena A; Chernitsyna, Svetlana M; Mamaeva, Elena V; Pogodaeva, Tatyana V; Zemskaya, Tamara I

    2016-01-01

    The ability to compare the composition and metabolic potential of microbial communities inhabiting the subsurface sediment in geographically distinct locations is one of the keys to understanding the evolution and function of the subsurface biosphere. Prospective areas for study of the subsurface biosphere are the sites of hydrocarbon discharges on the bottom of the Lake Baikal rift, where ascending fluxes of gas-saturated fluids and oil from deep layers of bottom sediments seep into near-surface sediment. The samples of surface sediments collected in the area of the Posolskaya Bank methane seep were cultured for 17 months under thermobaric conditions (80°C, 5 MPa) with the addition of complementary organic substrate, and a different composition for the gas phase. After incubation, the presence of intact cells of microorganisms, organic matter transformation and the formation of oil biomarkers was confirmed in the samples, with the addition of Baikal diatom alga Synedra acus detritus, and gas mixture CH4:H2:CO2. Taxonomic assignment of the 16S rRNA sequence data indicates that the predominant sequences in the enrichment were Sphingomonas (55.3%), Solirubrobacter (27.5%) and Arthrobacter (16.6%). At the same time, in heat-killed sediment and in sediment without any additional substrates, which were cultivated in a CH4 atmosphere, no geochemical changes were detected, nor the presence of intact cells and 16S rRNA sequences of Bacteria and Archaea. This data may suggest that the decomposition of organic matter under culturing conditions could be performed by microorganisms from low-temperature sediment layers. One possible explanation of this phenomenon is migration of the representatives of the deep thermophilic community through fault zones in the near surface sediment layers, together with gas-bearing fluids. PMID:27242716

  2. Isotopic composition of dissolved inorganic carbon in subsurface sediments of gas hydrate-bearing mud volcanoes, Lake Baikal: implications for methane and carbonate origin

    NASA Astrophysics Data System (ADS)

    Krylov, Alexey A.; Khlystov, Oleg M.; Hachikubo, Akihiro; Minami, Hirotsugu; Nunokawa, Yutaka; Shoji, Hitoshi; Zemskaya, Tamara I.; Naudts, Lieven; Pogodaeva, Tatyana V.; Kida, Masato; Kalmychkov, Gennady V.; Poort, Jeffrey

    2010-06-01

    We report on the isotopic composition of dissolved inorganic carbon (DIC) in pore-water samples recovered by gravity coring from near-bottom sediments at gas hydrate-bearing mud volcanoes/gas flares (Malenky, Peschanka, Peschanka 2, Goloustnoe, and Irkutsk) in the Southern Basin of Lake Baikal. The δ13C values of DIC become heavier with increasing subbottom depth, and vary between -9.5 and +21.4‰ PDB. Enrichment of DIC in 13C indicates active methane generation in anaerobic environments near the lake bottom. These data confirm our previous assumption that crystallization of carbonates (siderites) in subsurface sediments is a result of methane generation. Types of methanogenesis (microbial methyl-type fermentation versus CO2-reduction) were revealed by determining the offset of δ13C between dissolved CH4 and CO2, and also by using δ13C and δD values of dissolved methane present in the pore waters. Results show that both mechanisms are most likely responsible for methane generation at the investigated locations.

  3. 1000 years of climate variability in central Asia: assessing the evidence using Lake Baikal (Russia) diatom assemblages and the application of a diatom-inferred model of snow cover on the lake

    NASA Astrophysics Data System (ADS)

    Mackay, Anson W.; Ryves, D. B.; Battarbee, R. W.; Flower, R. J.; Jewson, D.; Rioual, P.; Sturm, M.

    2005-04-01

    The mainly endemic phytoplankton record of Lake Baikal has been used in this study to help interpret climate variability during the last 1000 years in central Asia. The diatom record was derived from a short core taken from the south basin and has been shown to be free from any sedimentary heterogeneities. We employ here a diatom-based inference model of snow accumulation on the frozen lake for the first time ( r2boot=0.709; RMSEP=0.120 log cm). However, palaeoenvironmental reconstructions have been improved by the use of correction factors, specifically developed for the dominant phytoplankton ( Aulacoseira baicalensis, Aulacoseira skvortzowii, Cyclotella minuta, Stephanodiscus meyerii and Synedra acus) in the south basin of Lake Baikal. Cluster analysis identifies three significant zones in the core, zone 1 (c. 880 AD-c. 1180 AD), zone 2 (c. 1180-1840 AD) and zone 3 (c. 1840-1994 AD), coincident with the Medieval Warm Period (MWP), the Little Ice Age (LIA) and the period of recent warming, respectively. Our results indicate that S. acus dominated the diatom phytoplankton within zone 1 coincident with the MWP. S. acus is an opportunistic species that is able to increase its net growth when A. baicalensis does not. During this period, conditions are likely to have been unfavourable for the net increases in A. baicalensis growth due to the persistence of warm water in the lake, together with an increased length of summer stratification and delay in timing of the autumnal overturn. In zone 2, spring diatom crops blooming under the ice declined in abundances due in part to increased winter severity and snow cover on the lake. Accumulating snow on the lake is likely to have arisen from increased anticyclonic activity, resulting in prolonged winters expressed during the LIA. Thick, accumulating snow cover inhibits light penetration through the ice, thereby having negative effects on cell division rate and extent of turbulence underneath the ice. Consequently, only taxa

  4. Geochemical and microbiological characteristics of sediments near the Malenky mud volcano (Lake Baikal, Russia), with evidence of Archaea intermediate between the marine anaerobic methanotrophs ANME-2 and ANME-3

    NASA Astrophysics Data System (ADS)

    Zemskaya, Tamara I.; Pogodaeva, Tatiayna V.; Shubenkova, Olga V.; Сhernitsina, Svetlana M.; Dagurova, Olga P.; Buryukhaev, Savelii P.; Namsaraev, Bair B.; Khlystov, Oleg M.; Egorov, Aleksandr V.; Krylov, Aleksei A.; Kalmychkov, Gennadii V.

    2010-06-01

    Detailed lithological, biogeochemical and molecular biological analyses of core sediments collected in 2002-2006 from the vicinity of the Malenky mud volcano, Lake Baikal, reveal considerable spatial variations in pore water chemical composition, with total concentrations of dissolved salts varying from 0.1 to 1.8‰. Values of methane δ13С in the sediments suggest a biogenic origin (δ13Сmin. -61.3‰, δ13Сmax. -72.9‰). Rates of sulphate reduction varied from 0.001 to 0.7 nmol cm-3 day-1, of autotrophic methanogenesis from 0.01 to 2.98 nmol CH4 cm-3 day-1, and of anaerobic oxidation of methane from 0 to 12.3 nmol cm-3 day-1. These results indicate that methanogenic processes dominate in gas hydrate-bearing sediments of Lake Baikal. Based on clone libraries of 16S rRNA genes amplified with Bacteria- and Archaea-specific primers, investigation of microbial diversity in gas hydrate-bearing sediments revealed bacterial 16S rRNA clones classified as Deltaproteobacteria, Gammaproteobacteria, Chloroflexi and OP11. Archaeal clone sequences are related to the Crenarchaeota and Euryarchaeota. Baikal sequences of Archaea form a distinct cluster occupying an intermediate position between the marine groups ANME-2 and ANME-3 of anaerobic methanotrophs.

  5. Status and perspectives of the BAIKAL-GVD project

    NASA Astrophysics Data System (ADS)

    Avrorin, A. D.; Avrorin, A. V.; Aynutdinov, V. M.; Bannash, R.; Belolaptikov, I. A.; Bogorodsky, D. Yu.; Brudanin, V. B.; Budnev, N. M.; Danilchenko, I. A.; Domogatsky, G. V.; Doroshenko, A. A.; Dyachok, A. N.; Dzhilkibaev, Zh.-A. M.; Fialkovsky, S. V.; Gafarov, A. R.; Gaponenko, O. N.; Golubkov, K. V.; Gress, T. I.; Honz, Z.; Kebkal, K. G.; Kebkal, O. G.; Konischev, K. V.; Konstantinov, E. N.; Korobchenko, A. V.; Koshechkin, A. P.; Koshel, F. K.; Kozhin, A. V.; Kulepov, V. F.; Kuleshov, D. A.; Ljashuk, V. I.; Milenin, M. B.; Mirgazov, R. A.; Osipova, E. R.; Panfilov, A. I.; Pan'kov, L. V.; Perevalov, A. A.; Pliskovsky, E. N.; Rozanov, M. I.; Rubtzov, V. Yu.; Rjabov, E. V.; Shaybonov, B. A.; Sheifler, A. A.; Skurihin, A. V.; Smagina, A. A.; Suvorova, O. V.; Tabolenko, V. A.; Tarashansky, B. A.; Yakovlev, S. A.; Zagorodnikov, A. V.; Zhukov, V. A.; Zurbanov, V. L.

    2016-07-01

    The neutrino telescope Baikal-GVD in Lake Baikal will be a research infrastructure aimed mainly at studying astrophysical neutrino fluxes. The telescope will consist of clusters of strings - functionally independent sub-arrays. The deployment of the first demonstration cluster has been started in April 2013. In 2014 the deployment of the second stage of the demonstration cluster has been performed. We describe the configuration and design of the first GVD cluster and review the current status of cluster deployment in Lake Baikal.

  6. A computer-assisted thin-section study of Lake Baikal sediments: a tool for understanding sedimentary processes and deciphering their climatic signal

    NASA Astrophysics Data System (ADS)

    Francus, Pierre; Karabanov, Eugene

    A freeze-drying technique for cutting thin-sections of soft sediments without disturbance is used to study several Lake Baikal sedimentary microstructures. Image analysis methodology is applied to selected thin-sections. This new technique provides quantification of the size, shape, orientation and packing of the objects forming the sedimentary structures. Sedimentary processes, which were previously poorly documented, have been identified, and others are better understood. Spheroidal lens-like pure aggregates of the diatom genus Synedra are found in hemipelagic sediments, providing a new insight into their traditional paleoecological interpretation. They are possibly related to a transportation mechanism from the littoral zone or to lacustrine snow. Laminae of Aulacoseira have also been recorded. Evidence of rapid sedimentation suggests they are due to massive algal blooms. The depositional mechanism that was suggested by other studies for explaining the laminations at the Buguldeika uplift is confirmed: the hemipelagic sedimentation is interrupted by terrigenous pulses due to discharge events. The sedimentation rate appears to be increasing during these pulses. Preliminary results from the Academician Ridge show stronger microbioturbation during cold periods. This observation strengthens the hypothesis of intense water circulation during colder times. Thin-section image analysis provides crucial information for deciphering lacustrine records and their regional and palaeoclimatic significance.

  7. High-resolution diatom analyses of holocene deposits from lake baikal: preliminary results for the records from continent ridge, posolsky bank and vydrino shoulder

    NASA Astrophysics Data System (ADS)

    Rioual, P.; Morley, D.; Mackay, A. W.

    2003-04-01

    Most studies on the sedimentary diatom assemblages of Lake Baikal have either focused on the very recent past or have been carried out at low sampling resolution on sequences that encompass several glacial/interglacial cycles. Here we present the progress made so far on the high-resolution diatoms analysis of the Holocene records found in three sites, one located in the North basin (Continent Ridge), and two located in the South basin (Posolsky Bank and Vydrino Shoulder). Samples are being analysed at a 5 mm resolution throughout the Holocene record for Vydrino Shoulder and every 1 cm for Posolsky Bank. At Continent Ridge, diatom analysis was carried out every 2 mm on the uppermost 20 cm of the core, while samples for the rest of the Holocene record were analysed every 1 cm only. We expect these to reflect a decadal to centennial resolution. From these three sequences, a very large number of diatom taxa (about 500) have been identified. In all three sequences, endemic planktonic diatoms dominate the assemblages. Species shifts common to all three sequences can be identified such as the rising percentages of Aulacoseira baicalensis and A. skvortzowii (species blooming under the ice in Spring) and the relative decline of Cyclotella minuta (that blooms during the Autumn overturn) at the top of the sequences, perhaps associated with the end of the Little Ice Age. Further down core, a peak of Stephanodiscus parvus, the rise in percentages of Cyclostephanos dubius and the decline of the endemic Stephanodiscus flabellatus also represent distinct species shifts. The cosmopolitan S. parvus and C. dubius are thought to indicate higher nutrient status. These features appear to be lake-wide and can maybe be used to correlate the sequences. Differences in species succession, however, are also apparent between the three records. Large peaks of Hannaea arcus, a periphytic diatom, and Asterionella formosa, a cosmopolitan planktonic species, for example are only found at Vydrino

  8. The optical detection unit for Baikal-GVD neutrino telescope

    NASA Astrophysics Data System (ADS)

    Avrorin, A. D.; Avrorin, A. V.; Aynutdinov, V. M.; Bannash, R.; Belolaptikov, I. A.; Bogorodsky, D. Yu.; Brudanin, V. B.; Budnev, N. M.; Danilchenko, I. A.; Domogatsky, G. V.; Doroshenko, A. A.; Dyachok, A. N.; Dzhilkibaev, Zh.-A. M.; Fialkovsky, S. V.; Gafarov, A. R.; Gaponenko, O. N.; Golubkov, K. V.; Gress, T. I.; Honz, Z.; Kebkal, K. G.; Kebkal, O. G.; Konischev, K. V.; Konstantinov, E. N.; Korobchenko, A. V.; Koshechkin, A. P.; Koshel, F. K.; Kozhin, A. V.; Kulepov, V. F.; Kuleshov, D. A.; Ljashuk, V. I.; Milenin, M. B.; Mirgazov, R. A.; Osipova, E. R.; Panfilov, A. I.; Pan'kov, L. V.; Perevalov, A. A.; Pliskovsky, E. N.; Rozanov, M. I.; Rubtzov, V. Yu.; Rjabov, E. V.; Shaybonov, B. A.; Sheifler, A. A.; Skurihin, A. V.; Smagina, A. A.; Suvorova, O. V.; Tabolenko, V. A.; Tarashansky, B. A.; Yakovlev, S. A.; Zagorodnikov, A. V.; Zhukov, V. A.; Zurbanov, V. L.

    2016-07-01

    The first stage of the GVD-cluster composed of five strings was deployed in April 2014. Each string consists of two sections with 12 optical modules per section. A section is the basic detection unit of the Baikal neutrino telescope. We will describe the section design, review its basic elements - optical modules, FADC readout units, slow control and calibration systems, and present selected results for section in-situ tests in Lake Baikal.

  9. The behavior of uranium and manganese under the diagenesis of carbonate sediments in small lakes of the Baikal region

    NASA Astrophysics Data System (ADS)

    Vosel, Yu. S.; Strakhovenko, V. D.; Makarova, I. V.; Vosel, S. V.

    2015-05-01

    This report considers the experimental studies of diagenetic processes involving uranium and manganese in lacustrine sediments, especially to prove the possibility of formation of UO2 + x reduced phases. Comparative research was performed for two lakes of different depths, hydrological conditions, mineralization, and chemical composition of waters. The layerwise successive leaching of sediments was carried out, with subsequent measurement of the contents of the uranium-238 and -234 isotopes in chemogenic fractions of the sediment. By means of ESR and successive leaching, the profiles of the manganese oxide and hydroxide content over the section were obtained. The performed studies confirmed the hypothesis of the formation of UO2 + x reduced phases in sediments. The sediments of the deeper freshwater Alyaty Lake are characterized by an increase in the content of the UO2 + x reduced phases and a decrease of manganese oxides and hydroxides downwards and upwards through the section, respectively. This conforms quite well to the behavior of these elements in oceanic sediments. The shallow saline Tsagan-Tyrm Lake is characterized by the reverse situation: the bulk of the UO2 + x reduced phase occurs in upper layers where, in turn, the oxide phases of manganese are simply absent. This is caused by different reductive conditions in the sediments.

  10. [Genetic Differentiation of Populations of Baikal Endemic Sergentia baicalensis Tshern. (Diptera, Chironomidae)].

    PubMed

    Kravtsova, L S; Bukin, Yu S; Peretolchina, T E; Shcherbakov, D Yu

    2015-07-01

    The population structure of endemic species Sergentia baicalensis (Diptera, Chironomidae) from Lake Baikal was studied using the first subunit of the cytochrome C oxidase mitochondrial gene (Col). Two populations inhabiting different basins of this lake, the southern-central and northern, were detected. It was confirmed that the divergence time of this species was dated to Late Miocene (9.53 ± 3.9 Mya), during the period when geographically separated basins existed in the Baikal rift zone. PMID:26410937

  11. Recent results of monitoring of the vertical component of the electrical field in Lake Baikal on the surface-bed baseline

    NASA Astrophysics Data System (ADS)

    Korotaev, S. M.; Budnev, N. M.; Serdyuk, V. O.; Zurbanov, V. L.; Mirgazov, R. R.; Shneer, V. S.; Machinin, V. A.; Kiktenko, E. O.; Buzin, V. B.; Panfilov, A. I.

    2015-05-01

    The vertical component of the electrical field was monitored on the surface-bed baseline in the region of the Baikal Deep Underwater Neutrino Observatory from 2003 to 2010. This monitoring allowed us to obtain data on internal and external field sources. However, the insufficient accuracy and reliability of the measurement setup slowed the progress in interpreting the measurements. A novel setup, which was the first to provide the means to control the base potentials of electrodes, was designed in order to overcome these constraints. The setup in its final configuration started taking measurements in 2013. Analysis of the measurement results obtained in 2013 and 2014 does, on the one hand, confirm the conclusions drawn previously on the nature of variations of the vertical component of the electrical field, but, on the other hand, it raises new questions. The field induced by flows was compared to direct velocity measurements. The conclusion regarding the correlation between long-period current variations in the hydrosphere region of the global electric circuit and the solar activity variations was confirmed, but the considerable lag observed in this correlation stands in need of explanation. A nonlocal response of the electrode base potentials that preceded an impending earthquake by up to 12 days was revealed.

  12. Timing of Early Proterozoic collisional and extensional events in the granulite-gneiss-charnockite-granite complex, Lake Baikal, USSR: A U-Pb, Rb-Sr, and Sm-Nd isotopic study

    SciTech Connect

    Aftalion, M. ); Bibikova, E.V. ); Bowes, D.R. ); Hopwood, A.M. ); Perchuk, L.L. )

    1991-11-01

    In the Sharyzhalgay Complex of the Lake Baikal region in eastern Siberia Early Proterozoic collisional and extensional events were separated by ca. 100 m.yr. The earlier collisional event, associated with the development of granulites and gneisses as the result of high-grade dynamothermal metamorphism, took place close to 1965 {plus minus} 4 Ma. A {sup 207}Pb/{sup 204}Pb vs. {sup 206}Pb/{sup 204}Pb isochron for zircon from five size fractions and a six point Rb-Sr whole-rock errorchron give generally corresponding ages of 1956 {plus minus} 8 and 1963 {plus minus} 163 Ma, respectively. The later extensional event, associated with charnockitization due to the uprise of fluids and heat in a regime corresponding to the middle to upper crustal levels of a Basin and Range-type province, was initiated in the 1880-1860 Ma period. The event was continued with magmatic emplacement of granitic masses into the deep levels of caldera-like structures, possibly during the upper time range of lower concordia intercept ages of 1817 +30/{minus}32 and 1797 +40/{minus}44 Ma for two distinctly different zircon populations in a pyroxene-bearing granodiorite interpreted as an evolved (and contaminated) product of the mantle-derived magma that was the source of CO{sub 2} involved in the charnockitization. Upper intercept ages of 2784 +48/{minus}45 and 2775 +61/{minus}55 Ma indicate late Archean crust at depth as the source region of the incorporated zircon. T{sub DM} ages from Sm-Nd isotopic data show that the protolith of the lithologically layered supracrustal assemblage, subsequently polyphase deformed and polymetamorphosed in Early Proterozoic times, was also formed in Early Proterozoic (not Archean) times.

  13. Hydrocarbon gases in Baikal bottom sediments: preliminary results of the Second international Class@Baikal cruise

    NASA Astrophysics Data System (ADS)

    Vidischeva, Olesya; Akhmanov, Grigorii; Khlystov, Oleg; Giliazetdinova, Dina

    2016-04-01

    In July 2015 the research cruise in the waters of Lake Baikal was carried out onboard RV "G.Yu. Vereshchagin". The expedition was organized by Lomonosov Moscow State University and Limnological Institute of Russian Academy of Sciences. The main purpose of the expedition was to study the modern sedimentation and natural geological processes on the bottom of Lake Baikal. One of the tasks of the cruise was to conduct gas-geochemical survey of bottom sediments. The samples of hydrocarbon gases were collected during the cruise. Subsequent study of the composition and origin of the sampled gas was carried out in the laboratories of Moscow State University. 708 samples from 61 bottom sampling stations were studied. Analyzed samples are from seven different areas located in the southern and central depressions of the lake: (1) "Goloustnoe" seepage area; (2) Bolshoy mud volcano; (3) Elovskiy Area; (4) "Krasny Yar" Seep; (5) "St. Petersburg" Seep; (6) Khuray deep-water depositional system; and (7) Kukuy Griva (Ridge) area. The results of molecular composition analysis indicate that hydrocarbon gases in bottom sediments from almost all sampling stations are represented mostly by pure methane. Ethane was detected only in some places within "Krasny Yar", "Goloustnoe" and "St. Petersburg" seepage areas. The highest concentrations of methane were registered in the sediments from the "Krasny Yar" area - 14 457 μl/l (station TTR-BL15-146G) - and from the "St. Petersburg" area - 13 684 μl/l (station TTR-BL15-125G). The sediments with high concentrations of gases were sampled from active fluid discharge areas, which also can be well distinguished on the seismic profiles. Gas hydrates were obtained in the areas of "Krasny Yar", "Goloustnoe", and "St. Petersburg" seeps and in the area of the Bolshoy mud volcano. Isotopic composition δ13C(CH4) was studied for 100 samples of hydrocarbon gases collected in areas with high methane concentration in bottom sediments. The average value is

  14. Overview of geology and tectonic evolution of the Baikal-Tuva area.

    PubMed

    Gladkochub, Dmitry; Donskaya, Tatiana

    2009-01-01

    This chapter provides the results of geological investigations of the main tectonic units of the Baikal-Tuva region (southwestern part of Siberia) during the last decades: the ancient Siberian craton and adjacent areas of the Central Asian Orogenic belt. In the framework of these main units we describe small-scale blocks (terranes) with focus on details of their inner structure and evolution through time. As well as describing the geology and tectonics of the area studied, we give an overview of underwater sediments, neotectonics, and some phenomena of history and development of the Baikal, Khubsugul, Chargytai, and Tore-Chol Lakes basins of the Baikal-Tuva region. It is suggested that these lakes' evolution was controlled by neotectonic processes, modern seismic activity, and global climate changes. PMID:19198771

  15. Determination of microelements in uncontaminated natural water from the Baikal region by atomic emission spectrometry

    SciTech Connect

    Kuznetsova, A.I.; Chumakova, N.L.

    1995-10-01

    In this study, concentration by evaporation was used to determine 17 microelements (B, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Mo, Ag, Sn, Ba, and Pb) in water from Lake Baikal and its tributaries by atomic-emission spectrometry with the arc excitation of spectra.

  16. P Wave Velocity Structure Beneath the Baikal Rift Axis

    NASA Astrophysics Data System (ADS)

    Brazier, R. A.; Nyblade, A. A.; Boman, E. C.

    2001-12-01

    Over 100 p wave travel times from the 1500 km en echelon Baikal Rift system are used in this study.The events range 3 to 13 degrees from Talaya, Russia (TLY) along the axis of southwest northeast trending rift in East Siberia. A Herglotz Wiechert inversion of these events resolved a crust of 6.4 km/s and a gradient in the mantle starting at 35 km depth and 7.7 km/s down to 200 km depth and 8.2 km/s. This is compatible with Gao et al,1994 cross sectional structure which cuts the rift at about 400km from TLY. The Baikal Rift hosts the deepest lake and is the most seismically active rift in the world. It is one of the few continental rifts, it separates the Siberian craton and the Syan-Baikal mobile fold belt. Two events, the March 21 1999 magnitude 5.7 earthquake 638 km from TLY and the November 13th 1995 magnitude 5.9 earthquake 863 km from TLY were modeled for there PnL wave structure using the discrete wavenumber method and the Harvard CMT solutions with adjusted depths from p-pP times. The PnL signals match well. A genetic algorithm will used to perturb the velocity structure and compare to a selection of the events between 3 and 13 degrees many will require moment tensor solutions.

  17. Sequentially sampled gas hydrate water, coupled with pore water and bottom water isotopic and ionic signatures at the Kukuy mud volcano, Lake Baikal: ambiguous deep-rooted source of hydrate-forming water

    NASA Astrophysics Data System (ADS)

    Minami, Hirotsugu; Hachikubo, Akihiro; Sakagami, Hirotoshi; Yamashita, Satoshi; Soramoto, Yusuke; Kotake, Tsuyoshi; Takahashi, Nobuo; Shoji, Hitoshi; Pogodaeva, Tatyana; Khlystov, Oleg; Khabuev, Andrey; Naudts, Lieven; De Batist, Marc

    2014-06-01

    The isotopic and ionic composition of pure gas hydrate (GH) water was examined for GHs recovered in three gravity cores (165-193 cm length) from the Kukuy K-9 mud volcano (MV) in Lake Baikal. A massive GH sample from core St6GC4 (143-165 cm core depth interval) was dissociated progressively over 6 h in a closed glass chamber, and 11 sequentially collected fractions of dissociated GH water analyzed. Their hydrogen and oxygen isotopic compositions, and the concentrations of Cl- and HCO3 - remained essentially constant over time, except that the fraction collected during the first 50 minutes deviated partly from this pattern. Fraction #1 had a substantially higher Cl- concentration, similar to that of pore water sampled immediately above (135-142 cm core depth) the main GH-bearing interval in that core. Like the subsequent fractions, however, the HCO3 - concentration was markedly lower than that of pore water. For the GH water fractions #2 to #11, an essentially constant HCO3 -/Cl- ratio of 305 differed markedly from downcore pore water HCO3 -/Cl- ratios of 63-99. Evidently, contamination of the extracted GH water by ambient pore water probably adhered to the massive GH sample was satisfactorily restricted to the initial phase of GH dissociation. The hydrogen and oxygen isotopic composition of hydrate-forming water was estimated using the measured isotopic composition of extracted GH water combined with known isotopic fractionation factors between GH and GH-forming water. Estimated δD of -126 to -133‰ and δ18O of -15.7 to -16.7‰ differed partly from the corresponding signatures of ambient pore water (δD of -123‰, δ18O of -15.6‰) and of lake bottom water (δD of -121‰, δ18O of -15.8‰) at the St6GC4 coring site, suggesting that the GH was not formed from those waters. Observations of breccias in that core point to a possible deep-rooted water source, consistent with published thermal measurements for the neighboring Kukuy K-2 MV. By contrast, the pore

  18. Comparative sequence stratigraphy of low-latitude versus high-latitude lacustrine rift basins: Seismic data examples from the East African and Baikal rifts

    USGS Publications Warehouse

    Scholz, C.A.; Moore, T.C., Jr.; Hutchinson, D.R.; Golmshtok, A. Ja; Klitgord, Kim D.; Kurotchkin, A.G.

    1998-01-01

    Lakes Baikal, Malawi and Tanganyika are the world's three largest rift valley lakes and are the classic modem examples of lacustrine rift basins. All the rift lakes are segmented into half-graben basins, and seismic reflection datasets reveal how this segmentation controls the filling of the rift basins through time. In the early stages of rifting, basins are fed primarily by flexural margin and axial margin drainage systems. At the climax of syn-rift sedimentation, however, when the basins are deeply subsided, almost all the margins are walled off by rift shoulder uplifts, and sediment flux into the basins is concentrated at accommodation zone and axial margin river deltas. Flexural margin unconformities are commonplace in the tropical lakes but less so in high-latitude Lake Baikal. Lake levels are extremely dynamic in the tropical lakes and in low-latitude systems in general because of the predominance of evaporation in the hydrologic cycle in those systems. Evaporation is minimized in relation to inflow in the high-latitude Lake Baikal and in most high-latitude systems, and consequently, major sequence boundaries tend to be tectonically controlled in that type of system. The acoustic stratigraphies of the tropical lakes are dominated by high-frequency and high-amplitude lake level shifts, whereas in high-latitude Lake Baikal, stratigraphic cycles are dominated by tectonism and sediment-supply variations.

  19. Geochronology of Holocene Soil Forming Processes in the Baikal Region

    NASA Astrophysics Data System (ADS)

    Danko, L.

    2012-04-01

    The chronology of soil formation in the Baikal Region is worked out poorly, and the issues concerning the soil cover development during the Holocene, still remain not fully understood. In this connection, the study of paleosols sequences which located on western Lake Baikal coast is interesting in all aspects. Features of pedogenic allow us to trace soil evolution in response to climatic and landscape changes, using morphological (color, texture, etc.) and analytical data (total organic carbon and nitrogen, humus content and composition, carbonate content, particle-size distribution, major and minor elemental compositions). Paleosols features suggest that the soils which were spread on the Primorsky Range piedmont about 7200±140 year BP coincide to Luvisols (WRB). The paleosols which were spread along the coast of the Lake Baikal between 7000-3200 calendar years ago are comparable to Chernozems (WRB). The principal attributes of the buried soil horizons with the age 4120±95 BP show maximum humus accumulation. This soil is distinguished by darker (black) color and high (up to 6%) humus content, and by the predominance of humic acids in humus composition. The Subatlantic pedogenesis is shown in the buried soil horizon with age of 2400, 1900 and 400 years. These soils are similar to the typical contemporaneous soils of this territory - Leptosols (WRB), except lower content of humus and exchange calcium for the Subatlantic soils. On the whole, the soils evolution of the studied area consists of three stages. First and foremost, it is the stage of Early Holocene shaping of the soil cover with pedogenic intermittence and weakness as a result of erosion and permafrost influence, with formation of skeletal soils of the organic-accumulation type. The next soil formation stage (Middle Holocene) characterized by a more stable state of soil cover, and by shaping of the Luvisols and Chernozems. Humus accumulation, carbonization and lessivage process dominated during this

  20. Crustal extension in the Baikal rift zone

    USGS Publications Warehouse

    Zorin, Yu; Cordell, L.

    1991-01-01

    Analysis of the gravity field along four profiles crossing the Baikal rift zone permits an estimate of the amount of anomalous mass produced by 1. (1) graben-fill sediments, 2. (2) Moho uplift and intrusion of mantle sills and dikes, 3. (3) an asthenospheric bulge. Crustal extension is evaluated based on the idea of mass and volume balance of material introduced into and removed from the initial volume of the crust. Extension in the Baikal rift increases southwestward from 0.9 km in the Chara depression to 19.3 km in the South Baikal depression. These values generally agree with the position of the Euler pole determined from seismic data (fault plane solutions). Average rotation velocity for the lithospheric plates separated by the rift zone is estimated to be 5.93 ?? 10-4 rad/m.y. over about 30 m.y. ?? 1991.

  1. Upper mantle P velocity structure beneath the Baikal Rift from modeling regional seismic data

    NASA Astrophysics Data System (ADS)

    Brazier, Richard A.; Nyblade, Andrew A.

    2003-02-01

    Uppermost mantle P wave velocity structure beneath the Baikal rift and southern margin of the Siberian Platform has been investigated by using a grid search method to model Pnl waveforms from two moderate earthquakes recorded by station TLY at the southwestern end of Lake Baikal. The results yielded a limited number of successful models which indicate the presence of upper mantle P wave velocities beneath the rift axis and the margin of the platform that are 2-5% lower than expected. The magnitude of the velocity anomalies and their location support the presence of a thermal anomaly that extends laterally beyond the rift proper, possibly created by small-scale convection or a plume-like, thermal upwelling.

  2. Velocity structure around the Baikal rift zone from teleseismic and local earthquake traveltimes and geodynamic implications

    NASA Astrophysics Data System (ADS)

    Petit, Carole; Koulakov, Ivan; Deverchère, Jacques

    1998-10-01

    We present new results on the velocity structure of the Baikal rift zone, Asia, deduced from a comparative teleseismic and local tomography analysis. The aim of this paper is to better identify the role of deep mantle processes versus that of far-field tectonic effects on the occurrence of extensional tectonics within a continental plate. We use 36000 traveltimes of P-refracted waves from the ISC catalogues and Pg and Pn traveltimes of 578 earthquakes recorded by the Russian regional network to determine a velocity model by the use of local and teleseismic inversion procedures. The models show that some velocity patterns are continuous from the surface down to at least 400 km. Among them, a narrow negative anomaly goes through Mongolia and follows the southern and eastern margins of the Siberian craton: this structure is interpreted as a thin mantle plume rising beneath the rift axis. However, our results do not evidence any wide asthenospheric upwarp at this place. Other velocity anomalies observed near the surface are not deeply rooted. In particular, a negative anomaly is observed at shallow levels (48 km) beneath the northern third of Lake Baikal, which is disconnected from deeper structures. It may be explained by the existence of underplated magmatic material at the bottom of the crust. By comparing the geometry of deep-rooted anomalies to the present-day stress field patterns, we conclude that the sub-lithospheric mantle dynamics is not the main factor controlling extensional processes in the Baikal rift. However, it does contribute to a thermal weakening of the lithosphere along a mechanical discontinuity bounding the Siberian shield. We finally conclude that three favourable conditions are gathered in the Baikal area to generate extension: far-field extensional stress field, mechanical inherited lithospheric weakness and heat supply. Further studies should help to precise the genetic link between these three factors.

  3. Class@Baikal: the Endurance of the UNESCO Training-Through-Research Programme

    NASA Astrophysics Data System (ADS)

    Mazzini, A.; Akhmanov, G.; Khlystov, O.; Tokarev, M.; Korost, D. V.; Poort, J.; Fokina, A.; Giliazetdinova, D. R.; Yurchenko, A.; Vodopyanov, S.

    2014-12-01

    In July 2014, by the initiative of the Moscow State University and Limnological Institute of Russian Academy of Sciences, the first Training-through-Research Class@Baikal was launched in Lake Baikal, Russia. The cruise program focused on seafloor sampling and acoustic investigations of gas seeps, flares, mud volcanoes, slumps and debris flows, canyons and channels in the coastal proximity. A comprehensive multidisciplinary program to train students has been developed to cover sedimentology, fluid geochemistry, biology, geophysics and marine geology in general. Daily lectures were conducted on board by academics presenting pertinent research projects, and cruise planning and preliminary results were discussed with all the scientific crew. A daily blog with updates on the expedition activities, images, and ongoing cruise results, was also completed (i.e. visit the cruise blog: http://baikal.festivalnauki.ru/) and gave the opportunity to interact with experts as well as attract the interest also of a broader audience. This project is a follow up to the well-established UNESCO Training-through-Research (TTR) Floating University Programme (http://floatinguniversity.ru/) that covered large areas on the European and arctic margins since 1991 with 18 research cruises attended by about 1000 BSc, MSc and PhD students from Europe, Asia, Africa and America. The crucial goal of both programmes is the training of new generations of scientists through active research directly on the field. Students can access the collected data and samples for their Master and PhD projects. Typically an extensive set of analyses and data processing is completed in-house and the results and interpretations are presented at post cruise meetings and international conferences. The Baikal lake is 25 million years old rift zone and provides a large variety of active geological features that can be easily reached at daily sailing distance. This represents an extraordinary opportunity to switch and focus

  4. Lake

    ERIC Educational Resources Information Center

    Wien, Carol Anne

    2008-01-01

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

  5. Geodynamics of the Baikal-Stanovoy seismic belt

    NASA Technical Reports Server (NTRS)

    Liu, H.-S.

    1983-01-01

    The convection generated tensional stress field in the earth, as inferred from satellite gravity data, reveals an anomalous lens of upwelling mantle rocks under the Baikal rift zone. The point of no strain at 56 deg N 116 deg E forms a seismic gap along the Baikal-Stanovoy seismic belt. East of this point, the stress field changes from extension to compression. Therefore, the position of no strain at the eastern termination of the rift accounts for the dying-out of the rift zone and for the appearance of a compressive structure in the Stanovoy Range.

  6. ANTARES and Baikal: Recent results from underwater neutrino telescopes

    NASA Astrophysics Data System (ADS)

    Schüssler, Fabian

    2016-07-01

    Two Northern hemisphere neutrino telescopes are currently searching for astrophysical neutrinos in the TeV/PeV range: ANTARES and Baikal. Both observatories utilize various signatures like a high energy excess over the atmospheric neutrino flux, searches for localized neutrino sources of various extensions and multi-messenger analyses based on time and/or space coincidences with other cosmic probes. We here review the status of both experiments and discuss a selection of recent results.

  7. Localization of the high-resolution area in the ganglion cell layer of the Baikal seal Pusa sibirica Gm.1788.

    PubMed

    Mass, A M

    2016-03-01

    The morphological and functional density of the retinal ganglion cells of the Baikal Lake endemic seal Pusa sibirica was studied using cresyl-violet-stained whole-mounts. An area of the highest concentration of ganglion cells has been identified by drawing up a density map. This was an ellipsoid spot in the upper temporal part of the retina 6-7 mm from the visual nerve output. The maximum cell density in this area was 3800 cells/mm(2). The retinal resolution estimated from the maximum density of ganglion cells and the posterior nodal distance (24 mm) was 2.4' in the water and 3' in the air, and this can be used as an estimation of the retina resolving power. PMID:27193874

  8. A search for neutrino signal from dark matter annihilation in the center of the Milky Way with Baikal NT200

    NASA Astrophysics Data System (ADS)

    Avrorin, A. D.; Avrorin, A. V.; Aynutdinov, V. M.; Bannasch, R.; Belolaptikov, I. A.; Bogorodsky, D. Yu.; Brudanin, V. B.; Budnev, N. M.; Danilchenko, I. A.; Demidov, S. V.; Domogatsky, G. V.; Doroshenko, A. A.; Dyachok, A. N.; Dzhilkibaev, Zh.-A. M.; Fialkovsky, S. V.; Gafarov, A. R.; Gaponenko, O. N.; Golubkov, K. V.; Gress, T. I.; Honz, Z.; Kebkal, K. G.; Kebkal, O. G.; Konischev, K. V.; Korobchenko, A. V.; Koshechkin, A. P.; Koshel, F. K.; Kozhin, A. V.; Kulepov, V. F.; Kuleshov, D. A.; Ljashuk, V. I.; Milenin, M. B.; Mirgazov, R. A.; Osipova, E. R.; Panfilov, A. I.; Pan'kov, L. V.; Pliskovsky, E. N.; Rozanov, M. I.; Rjabov, E. V.; Shaybonov, B. A.; Sheifler, A. A.; Shelepov, M. D.; Skurihin, A. V.; Smagina, A. A.; Suvorova, O. V.; Tabolenko, V. A.; Tarashansky, B. A.; Yakovlev, S. A.; Zagorodnikov, A. V.; Zhukov, V. A.; Zurbanov, V. L.

    2016-08-01

    We reanalyze the dataset collected during the years 1998-2003 by the deep underwater neutrino telescope NT200 in the lake Baikal with the low energy threshold (10 GeV) in searches for neutrino signal from dark matter annihilations near the center of the Milky Way. Two different approaches are used in the present analysis: counting events in the cones around the direction towards the Galactic Center and the maximum likelihood method. We assume that the dark matter particles annihilate dominantly over one of the annihilation channels bbbar , W+W- , τ+τ- , μ+μ- or ννbar . No significant excess of events towards the Galactic Center over expected neutrino background of atmospheric origin is found and we derive 90% CL upper limits on the annihilation cross section of dark matter.

  9. Burying Dogs in Ancient Cis-Baikal, Siberia: Temporal Trends and Relationships with Human Diet and Subsistence Practices

    PubMed Central

    Losey, Robert J.; Garvie-Lok, Sandra; Leonard, Jennifer A.; Katzenberg, M. Anne; Germonpré, Mietje; Nomokonova, Tatiana; Sablin, Mikhail V.; Goriunova, Olga I.; Berdnikova, Natalia E.; Savel’ev, Nikolai A.

    2013-01-01

    The first objective of this study is to examine temporal patterns in ancient dog burials in the Lake Baikal region of Eastern Siberia. The second objective is to determine if the practice of dog burial here can be correlated with patterns in human subsistence practices, in particular a reliance on terrestrial mammals. Direct radiocarbon dating of a suite of the region’s dog remains indicates that these animals were given burial only during periods in which human burials were common. Dog burials of any kind were most common during the Early Neolithic (∼7–8000 B.P.), and rare during all other time periods. Further, only foraging groups seem to have buried canids in this region, as pastoralist habitation sites and cemeteries generally lack dog interments, with the exception of sacrificed animals. Stable carbon and nitrogen isotope data indicate that dogs were only buried where and when human diets were relatively rich in aquatic foods, which here most likely included river and lake fish and Baikal seal (Phoca sibirica). Generally, human and dog diets appear to have been similar across the study subregions, and this is important for interpreting their radiocarbon dates, and comparing them to those obtained on the region’s human remains, both of which likely carry a freshwater old carbon bias. Slight offsets were observed in the isotope values of dogs and humans in our samples, particularly where both have diets rich in aquatic fauna. This may result from dietary differences between people and their dogs, perhaps due to consuming fish of different sizes, or even different tissues from the same aquatic fauna. This paper also provides a first glimpse of the DNA of ancient canids in Northeast Asia. PMID:23696851

  10. Coastal upwellings in 1941-2005 at Listvyanka settlement (Southern Baikal)

    NASA Astrophysics Data System (ADS)

    Troitskaya, Elena; Shimaraev, Mikhail; Zhdanov, Andrey; Zhdanova, Rita; Salva, Elena

    2010-05-01

    The first results of studies of coastal upwelling are presented in this paper based on long-term (1941-2005) measurements of surface water temperature in May-December at the pier of Limnological Institute (Listvyanka settlement, Southern Baikal). Listvyanka settlement is situated in Listvenichnoye Bay not far from the outlet of the Angara River. The flow of the Angara River is formed from the surface waters and ascending deep waters of Lake Baikal. Therefore, when the wind is of northwest direction, either surface waters are driven away along the northern shore or upwelling is formed if the wind blows for 2-3 days. Analyzing a temperature set, upwelling was considered in those cases when temperature dropped sharply by 2 or more degrees and it stayed for more than 3 days. Coastal upwelling developed more often in July and August in the area studied (it was recorded in 41 and 46 cases from 65 years analyzed), more rarely in September (in 36 cases from 65), seldom in October (in 16 from 65), 3 times in June (in 1948, 1972 and 1994), and once in November (1969). One-two upwellings were usually formed during a month. However, three-four upwellings were recorded in some years (July: 1949, 1974, 1976, 1994, 1996, 2003; August: 1942, 1955, 1972, 1973, 1975, 1976, 1978, 1982, 1990; and September: 1951, 2002). The duration of upwelling varied from 3 days to 3 weeks. The most long-lasting upwellings were recorded in August-September due to the intensification of wind activity above Lake Baikal in late summer. The temperature drop in the upwelling zone was 2.3-3.5°C in June, in July - 2.1-10.8 °C, in August - 2.2-11.9°C, in September - 2.5-11.2°C, in October - 2.1-7.5°C, and in November - 1.9°C. There were recorded some cases when the temperature decreased by more than 10°C (July 1949, August 1953, 1963, 1979, 1986, 1993, 2002, 2004, and September 1943, 1964, 1974). In some years, upwelling occurred every month in July-October or July-September (1974, 1984, 1987, 1988

  11. Postcambrian stratified rocks of the northern part of the Baikal-Vitim fold area

    NASA Astrophysics Data System (ADS)

    Buldygerov, V. V.; Krainov, M. A.

    2012-09-01

    The Ordovician stratified rocks previously referred to Riphean or Vendian are widespread in the northern part of the Baikal-Vitim fold area. They include volcanosedimentary rocks which accumulated in continental riftlike troughs after Vendian-Cambrian platform regime and were accompanied by subvolcanic bodies. The coarse-clastic facies, frequently olistostromes with olistoplaques, are abundant in the marginal parts of the troughs. The sandy-silty-clay rocks dominate in the centre. The volcanic rocks represent the contrast rhyolite-basaltic series and compose paleovolcanoes of the central type, locally, complicated by calderas. Tuffaceous material is nearly almost present in synchronous sedimentary rocks. In the Ordovician, the northern part of the Baikal-Vitim fold area was an uplift of island arc type complicated by the riftlike troughs. It occupied the central part of the Baikal-Vitim arc. The location of the troughs was subjected to its structural plan. They were formed successively after the Riphean-Vendian Baikal-Muya volcano-plutonic belt. The uplift existed within a shallow basin occupying nearly the entire Siberian Platform and Baikal-Vitim fold area. The data obtained confirm that marine sedimentary basin with islands sometimes existed within the Baikal-Vitim fold area and was a part of the basin occupying the adjacent part of the Siberian Platform. The effect of pulsating plume in the northern part of the Baikal-Vitim fold area periodically, including Ordovician, led to the origination of the uplift and to renewal of tectonic and volcano-plutonic activity.

  12. Basaltic Martian analogues from the Baikal Rift Zone and Mongolian terranes

    NASA Astrophysics Data System (ADS)

    Gurgurewicz, J.; Kostylew, J.

    2007-08-01

    In order to compare the results of studies of the western part of the Valles Marineris canyon on Mars there have been done field works on terrestrial surface areas similar with regard to geological setting and environmental conditions. One of the possible terrestrial analogues of the Valles Marineris canyon is the Baikal Rift Zone [1]. Field investigations have been done on the south end of the Baikal Lake, in the Khamar-Daban massif, where the outcrops of volcanic rocks occur. The second part of the field works has been done in the Mongolian terranes: Mandalovoo, Gobi Altay and Bayanhongor, because of environmental conditions being similar to those on Mars. The Mandalovoo terrane comprises a nearly continuous Paleozoic islandarc sequence [2]. In the Gobi Altay terrane an older sequence is capped by younger Devonian-Triassic volcanic-sedimentary deposits [2]. The Bayanhongor terrane forms a northwest-trending, discontinuous, narrow belt that consists of a large ophiolite allochton [3]. The collected samples of basalts derive from various geologic environments. The CORONA satellite-images have been used for the imaging of the Khamar-Daban massif and the Mandalovoo terrane. These images have the same spatial resolution and range as the Mars Orbiter Camera images of the Mars Global Surveyor mission. In the Mandalovoo terrane these images allowed to find an area with large amounts of tectonic structures, mainly faults (part of the Ongi massif), similar to the studied area on Mars. Microscopic observations in thin sections show diversification of composition and structures of basalts. These rocks have mostly a porphyric structure, rarely aphyric. The main components are plagioclases, pyroxenes and olivines phenocrysts, in different proportions. The groundmass usually consist of plagioclases, pyroxenes and opaques. The most diversified are basalts from the Mandalovoo terrane. Infrared spectroscopy has been used to analyse the composition of the rock material and compare

  13. Chemical and isotope compositions of nitric thermal water of Baikal rift zone

    NASA Astrophysics Data System (ADS)

    Plyusnin, A. M.; Chernyavsky, M. K.; Peryazeva, E. G.

    2010-05-01

    Three types of hydrotherms (nitric, carbonaceous and methane) are distinguished within the Baikal Rift Zone. The unloading sites of nitric therms are mostly located in the central and north-eastern parts of the Rift. Several chemical types are found among nitric therms (Pinneker, Pisarsky, Lomonosov, 1968; Lomonosov, 1974, etc.). The formation of terms being various in chemical compositions is associated with effect of several factors, i.e. various chemical, mineralogical compositions of rocks, various temperatures, extent of interaction in water-rock system, etc. The ratio data of water oxygen and hydrogen isotopes of the studied thermal springs indicate that water is largely of meteoric origin. All established ratios of oxygen (δ18OSMOW = -19.5‰ - -17.5‰) and hydrogen (δDSMOW = -155‰ - - 130‰) isotopes are along the line of meteoric waters. Oxygen values from -20‰ to -5‰ are characteristic of the current meteoric and surface waters in the region. The average value equals -16.5‰ in Lake Baikal. By our data, a large group with oxygen lighter isotope composition that corresponds to isotope ratio being specific for glaciers is revealed in fissure-vein waters. Significant shift toward the oxygen getting heavier is observed in some springs. It is mostly observed in the springs that form chemical composition within the area of the intrusive and metamorphic rock distribution. As a result of hydrolysis reaction of alumosilicates, heavy isotope passes from rocks into water molecule, whereas oxygen heavy isotope passes from rocks into solutes during decomposition of carbonates. High contents of fluoride and sulfate-ions are specific feature of the Baikal Rift Zone most nitric therms. Water is tapped in one of the drill holes, where fluoride-ion dominates in its anion composition (46.7 mg/dm3) and pH reaches 10, 12. The sulphate sulphur isotope composition studies carried out allow to conclude that its heavy isotope (δ34SCDT = +25‰ - +30‰) prevails in

  14. Intracontinental rift comparisons: Baikal and Rio Grande Rift Systems

    NASA Astrophysics Data System (ADS)

    Lipman, P. W.; Logatchev, N. A.; Zorin, Y. A.; Chapman, C. E.; Kovalenko, V.; Morgan, P.

    Both the Baikal rift in Siberia and the Rio Grande rift in New Mexico, Colorado and Texas are major intracontinental extensional structures of Cenozoic age that affect regions about 1500 km long and several hundred km wide (Figures 1, 2). In the summer of 1988 these rifts were visited by study groups of U.S. and Soviet geoscientists during cooperative field workshops sponsored by the Soviet Academy of Sciences, U.S. National Academy of Sciences, and U.S. Geological Survey.In the Rio Grande region, we spent 2 weeks examining rift features between El Paso, Tex., and Denver, Colo. Particular emphasis was on the sedimentary record of rift evolution, widespread volcanic activity from inception of rifting to the present, geophysical expression of rift features, and relations between rifting and the larger-scale evolution of the North American Cordillera. In the Baikal region, which presents formidable logistic problems for a workshop, we travelled by bus, truck, helicopter, and ship to examine young seismotectonic features, rift-related basalt, and bounding structures of the Siberian craton that influenced rift development (Figure 3).

  15. Microelements in solonchaks of the western Trans-Baikal region

    NASA Astrophysics Data System (ADS)

    Sosorova, S. B.; Merkusheva, M. G.; Boloneva, L. N.; Baldanova, A. L.; Ubugunov, L. L.

    2016-04-01

    Distribution patterns of microelements (Mn, Zn, Ni, Cu, Cr, Co, Pb, and Cd) in solonchaks of the western Trans-Baikal region were studied. It was found that their concentrations in typical solonchaks of haloxerophytic steppe differed from those in solonchaks of moistened habitats (playa, gleyed, and dark solonchaks) because of the differences in their landscape positions and ecological conditions. A general rise in the contents of the microelements was observed from the northeast to the southwest in agreement with changes in the parent materials. Different degrees of correlation of the contents of the microelements and their exchangeable forms with the contents of soluble salts, humus, and physical clay in the soils and the soil reaction were found. The average and extreme concentrations of the microelements were determined. The studied typical solonchaks differed from the zonal chestnut soils in the higher contents of Co, Cr, and Cd; whereas solonchaks of moistened habitats were enriched in Mn, Co, and Cd.

  16. Search for acoustic effects from extensive atmospheric showers in Baikal

    SciTech Connect

    Lyashuk, V.I. Novikov, E.G.

    2006-11-15

    The search for acoustic effects from showers by means of hydrophones was realized in a trigger scheme of recording sound files when atmospheric showers were detected by the scintillation installation. A method of peaks and noncoincidences was proposed to search for weak sound sources. The algorithm of the method is amplitude independent. Processing of a great body of data (obtained for different geometries, different noise background during three expeditions to Baikal) allows one to indicate the closely analogous phenomena at the instant of time of expected sound signals from showers. In spite of their low power, the effects appear in the different hydrophones and have similar time distributions, which points to the detection of the acoustic effects.

  17. [Anoxygenic phototrophic bacteria from microbial communities of Goryachinsk Thermal Spring (Baikal Area, Russia)].

    PubMed

    Kalashnikov, A M; Gaĭsin, V A; Sukhacheva, M V; Namsaraeva, B B; Panteleeva, A N; Nuianzina-Boldareva, E N; Kuznetsov, B B; Gorlenko, V M

    2014-01-01

    Species composition of anoxygenic phototrophic bacteria in microbial mats of the Goryachinsk thermal spring was investigated along the temperature gradient. The spring belonging to nitrogenous alkaline hydrotherms is located at the shore of Lake Baikal 188 km north-east from Ulan-Ude. The water is of the sulfate-sodium type, contains trace amounts of sulfide, salinity does not exceed 0.64 g/L, pH 9.5. The temperature at the outlet of the spring may reach 54 degrees C. The cultures of filamentous anoxygenic phototrophic bacteria, nonsulfur and sulfur purple bacteria, and aerobic anoxygenic phototrophic bacteria were identified using the pufLM molecular marker. The fmoA marker was used for identification of green sulfur bacteria. Filamentous cyanobacteria predominated in the mats, with anoxygenic phototrophs comprising a minor component of the phototrophic communities. Thermophilic bacteria Chloroflexus aurantiacus were detected irn the samples from both the thermophilic and mesophilic mats. Cultures ofnonsulfur purple bacteria similar to Blastochloris sulfoviridis and Rhodomicrobium vannielii were isolatd from the mats developing at high (50.6-49.4 degrees C) and low temperatures (45-20 degrees C). Purple sulfur bacteria Allochromatium sp. and Thiocapsa sp., as well as green sulfur bacteria Chlorobium sp., were revealedin low-temperature mats. Truly thermophilic purple and gree sulfur bacteria were not found in the spring. Anoxygenic phototrophic bacteria found in the spring were typical of the sulfuret communities, for which the sulfur cycle is mandatory. The presence of aerobic bacteriochlorophylla-containing bacteria identified as Agrobacterium (Rhizobium) tumifaciens in the mesophilic (20 degrees C) mat is of interest. PMID:25844460

  18. Contemporary surface ruptures in the zone of the Baikal-Mondy fault (Baikal rift system): dynamics of formation and origin

    NASA Astrophysics Data System (ADS)

    Sankov, Vladimir; Sankov, Aleksei; Lebedeva, Marina; Ashurkov, Sergey; Parfeevets, Anna

    2014-05-01

    Sublatitudinal Baikal-Mondy (Tunka) left-lateral strike-slip fault accommodates North Mongolia submeridional rift basins opening (Darkhad and Khubsugul). It is the connecting link between the central and south-western parts of the Baikal rift system. We investigated the present-day activity of faulting on southern border of Mondy basin, which is due to their position at the junction of east-west trending active faults of the Baikal-Mondy fault system with submeridional structures of Khubsugul basin. The investigated area is characterized by high seismic activity. The epicenter of one of the strongest Mondy earthquake 1950 (Mw = 7.0) is located within the Mondy basin. Reconstruction of Late Cenozoic tectonic stress field shows a predominance of strike-slip deformation regime with NW-SE direction of the minimum compression axis and NE-SW direction of the maximum compression axis, which correlates with the present-day stress field derived from the data on earthquake focal mechanisms. On the top of the southern shoulder of Mondy basin a series of extended NE trending surface ruptures that cut the crust of weathering and bedrock across the local watershed were discovered. The rupture length reaches 180 m, width ruptures bedrock reaches 0.6 m. In the bedrock tectonic microfractures of NW and NE directions are dominated, but the NW trending surface ruptures are not observed. In the area of contemporary ruptures the geodetic measurements were carried out in the period 2009-2013. The results of processing the measurement data on the local testing ground showed that most divergent baselines undergoes extension with maximum values reaching 30 mm/year. The block experienced elongation in all directions, but the morphology of ruptures suggests that the main direction of stretching is NW-SE. The intensity of cracks opening decreases markedly with time. According to eyewitnesses known that active crack opening at about 100 mm/year started 4 years before Kultuk earthquake (27

  19. Chromospheric telescope of Baikal Astrophysical Observatory. New light

    NASA Astrophysics Data System (ADS)

    Skomorovsky, Valeriy; Kushtal, Galina; Lopteva, Lyubov; Proshin, Vladimir; Trifonov, Viktor; Chuprakov, Sergey; Khimich, Valeriy

    2016-06-01

    A chromospheric telescope is an important instrument for synoptic observations and solar research. After several decades of observations with the chromospheric telescope at Baikal Astrophysical Observatory, a need arose to improve the characteristics of this telescope and filter. A new reimaging lens to produce full-disk solar images 18 mm in diameter at the CCD camera Hamamatsu C-124 with a detector 36×24 mm (4000×2672 pixels) was designed and manufactured to replace the out-of-operation 50×50 mm Princeton Instruments camera. A contrast interference blocking filter and a new Iceland spar and quartz crystal plates instead of damaged ones were made and installed in the Hα birefringent filter (BF), manufactured by Bernhard Halle Nachfl. The optical immersion in the filter was changed. All telescope optics was cleaned and adjusted. We describe for the first time the design features and their related BF passband tuning. The wavefront interferograms of optical elements and telescope as a whole show that the wavefront distortion of the optical path is within 0.25 λ. The BF and pre-filter spectral parameters provide high-contrast monochromatic images. Besides, we give examples of solar chromospheric images in the Hα line core and wing.

  20. Chromospheric telescope of Baikal Astrophysical Observatory. New light

    NASA Astrophysics Data System (ADS)

    Skomorovsky, Valeriy; Kushtal, Galina; Lopteva, Lyubov; Proshin, Vladimir; Trifonov, Viktor; Chuprakov, Sergey; Khimich, Valeriy

    2016-06-01

    A chromospheric telescope is an important instrument for synoptic observations and solar research. After several decades of observations with the chromospheric telescope at Baikal Astrophysical Observatory, a need arose to improve the characteristics of this telescope and filter. A new reimaging lens to produce full-disk solar images 18 mm in diameter at the CCD camera Hamamatsu C-124 with a detector 36×24 mm (4000×2672 pixels) was designed and manufactured to replace the out-of-operation 50×50 mm Princeton Instruments camera. A contrast interference blocking filter and a new Iceland spar and quartz crystal plates instead of damaged ones were made and installed in the Hα birefringent filter (BF), manufactured by Bernhard Halle Nachfl. The optical immersion in the filter was changed. All telescope optics was cleaned and adjusted. We describe for the first time the design features and their related BF passband tuning. The wavefront interferograms of optical elements and telescope as a whole show that the wavefront distortion of the optical path is within 0.25 λ. The BF and pre-filter spectral parameters provide high-contrast monochromatic images. Besides, we give examples of solar chromospheric images in the H&apha; line core and wing.

  1. Concentration of nutrients in the water of Southern Baikal in summer

    NASA Astrophysics Data System (ADS)

    Sakirko, M. V.; Domysheva, V. M.; Pestunov, D. A.; Netsvetaeva, O. G.; Panchenko, M. V.

    2015-11-01

    Optical characteristics of Baikal water and their inter-annual, seasonal and diurnal variability depend on plankton composition, suspended particles of organic and inorganic substances, and dissolved chemical compounds. This work analyses the results of comprehensive studies on spatial distribution of nutrients (nitrogen, phosphorus, carbon, and silicon) in the water area of Southern Baikal performed in August 2014. The authors also compare the results of spatial measurements with the data of long-term observations in the littoral zone for summer conditions carried out at the Scientific Research Station of Limnological Institute of the Siberian Branch of the Russian Academy of Sciences.

  2. Stable isotope composition of Earth's large lakes

    NASA Astrophysics Data System (ADS)

    Jasechko, S.; Gibson, J. J.; YI, Y.; Birks, S. J.; Sharp, Z. D.

    2011-12-01

    Lakes cover about three percent of Earth's continental area. Large lakes can significantly influence lake shore and regional climates by increasing specific humidity during evaporation and by moderating air temperatures. Stable isotopes of oxygen and hydrogen can be used to quantify lake evaporation, providing a supplementary and often cost-advantageous alternative to conventional hydrologic approaches that require over lake monitoring. Further, stable isotopes in lake sediments are an established tool in paleolimnology; however, interpreting changes to a lake's past isotope composition requires a comprehensive understanding of contemporary controls. Here, δ18O and δ2H values of water in modern lakes exceeding roughly five hundred square kilometres are compiled (n > 35). Voluminous and seasonally mixed lakes - such as the North American Great Lakes - have the most homogenous stable isotope compositions, while perennially-stratified and shallow lakes show greater variability. A rudimentary stable isotope mass balance is used to assess evaporation fluxes from large lakes on Earth. The approach taken simultaneously constrains evaporation outputs for both oxygen and hydrogen stable isotopes by accounting for lake effects on the overlying atmosphere. Model development highlights important considerations such as isotopic stratification (Tanganyika), disequilibrium isotopic mass balances (Baikal), and non-steady hydrologic balances. Further, the isotope composition of Earth's continental surface water reservoir is calculated. This value - weighted to volume - is δ18O = -7.5±1.7 per mille relative to standard mean ocean water. The compiled data may be a useful tracer of continental evaporate in global atmospheric water cycle studies and could be coupled to climate models capable of incorporating oxygen-18 and deuterium tracers to improve or validate calculations of lake effects on regional water cycling.

  3. Quality Assessment and Yield of Baikal Skullcap (Scutellaria baicalensis) Grown at Multiple Locations Across Mississippi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Baikal skullcap (Scutellaria baicalensis) is an important medicinal plant with proven bioactivity. In the US and other countries, commercially available products containing extracts or derivatives from this plant species have been shown to have issues with consistency of chemical composition and bi...

  4. a system approach to the long term forecasting of the climat data in baikal region

    NASA Astrophysics Data System (ADS)

    Abasov, N.; Berezhnykh, T.

    2003-04-01

    The Angara river running from Baikal with a cascade of hydropower plants built on it plays a peculiar role in economy of the region. With view of high variability of water inflow into the rivers and lakes (long-term low water periods and catastrophic floods) that is due to climatic peculiarities of the water resource formation, a long-term forecasting is developed and applied for risk decreasing at hydropower plants. Methodology and methods of long-term forecasting of natural-climatic processes employs some ideas of the research schools by Academician I.P.Druzhinin and Prof. A.P.Reznikhov and consists in detailed investigation of cause-effect relations, finding out physical analogs and their application to formalized methods of long-term forecasting. They are divided into qualitative (background method; method of analogs based on solar activity), probabilistic and approximative methods (analog-similarity relations; discrete-continuous model). These forecasting methods have been implemented in the form of analytical aids of the information-forecasting software "GIPSAR" that provides for some elements of artificial intelligence. Background forecasts of the runoff of the Ob, the Yenisei, the Angara Rivers in the south of Siberia are based on space-time regularities that were revealed on taking account of the phase shifts in occurrence of secular maxima and minima on integral-difference curves of many-year hydrological processes in objects compared. Solar activity plays an essential role in investigations of global variations of climatic processes. Its consideration in the method of superimposed epochs has allowed a conclusion to be made on the higher probability of the low-water period in the actual inflow to Lake Baikal that takes place on the increasing branch of solar activity of its 11-year cycle. The higher probability of a high-water period is observed on the decreasing branch of solar activity from the 2nd to the 5th year after its maximum. Probabilistic method

  5. Petrology and Geochemistry of mantle xenoliths from Margasan, Baikal Lake region (Russia) Preliminary results

    NASA Astrophysics Data System (ADS)

    Dippenaar, Elijah; Ntaflos, Theodoros; Ashchepkov, Igor

    2014-05-01

    Off-cratonic mantle xenoliths collected from the Margasan volcanic field in eastern Siberia (Russia) were analysed to characterize their mineralogical composition, their petrological and geochemical properties. The xenoliths are spinel bearing lherzolithe and have been transported to the surface by alkali basalts. The studied samples are fertile lherzolithes with modal compositions as follows: Forsterite 56% - 78%, orthopyroxene 35% - 16%, clinopyroxene 6% - 20% and spinel 0% - 4.5%. The majority of the samples have textures ranging from protogranular to equigranular. Some of the samples with equigranular texture show characteristic foliation suggesting deformation in the depths. Frequently, olivine grains show kink-bands. The clinopyroxenes show characteristic spongy rims with variable width as a consequence of interaction with interganulate circulating melts/fluids. Alternatively they could be formed en route to the surface due to pressure decrease. Microprobe analyses have shown that Forstertite (Fo) contents in olivine vary from 89 to 90. The mg#*100 in orthopyroxene and clinopyroxene ranges from 90 to 90.5 and 89 to 91 respectively. Spinels are Al2O3-rich with 100*cr# ranging from 9 to 17. The TiO2, Cr2O3 and Na2O contents in clinopyroxene vary from 0.4% to 0.7%, 0.6% to 1.1% and 0.6 to 2.1 respectively. The clinopyroxene spongy rims consist of glass and second generation clinopyroxene, which differs from the primary clinopyroxenes in that the TiO2, Al2O3 and Na2O contents are lower than in the primary clinopyroxenes. According to the model of batch melting the studied xenoliths indicate that they are the residues after 1.5% to 7% partial melting. The calculated equilibrium temperature at a pressure of 15kbar ranges from 940°C to 1120°C, indicating that xenoliths have been sampled from different depths.

  6. Comparative ecology of exotic invaders and ecologically equivalent species of hydrobionths in the Great Lakes of the world: Results of Russia-USA cooperation

    USGS Publications Warehouse

    Pronin, N.M.; Fleischer, G.W.; Kohl, S. G.; Korsunov, V. M.; Baldanova, D.R.; Bronte, C.R.; Garmayeva, C. H.; Hatcher, C. H.; Hoff, M.H.; Maistrenko, S.G.; Nester, R.; O'Gorman, Robert; Owens, R.W.; Pronina, S.V.; Selgeby, J.H.; Sokolnikov, Yury; Todd, N. T.

    1999-01-01

    This paper presents brief fragments of the results of joint Russia-US research conducted through the cooperative project entitled, 'Comparative ecology of exotic invaders and ecologically equivalent species of hydrobionths in the Great Lakes of the world: Lake Baikal and the Laurentian Great Lakes.' The project was executed under the Agreement on Scientific Cooperation between the Institute of General and Experimental Biology (formerly Buryat Institute of Biology) of the Siberian Branch of the Russian Academy of Sciences and the Great Lakes Science Center of the U.S. Geological Survey.

  7. Attractor structures of riftogenesis in the lithosphere of Baikal Rift System

    NASA Astrophysics Data System (ADS)

    Klyuchevskii, A. V.

    2011-03-01

    The study results of modern geodynamics and tectonophysics of the lithosphere of Baikal Rift System (BRS) are generalized. By the data on radii of dislocations, three areas of maximal strain-strength anisotropy of the medium are distinguished, while analysis of seismic moments of earthquakes has showed that in these parts of the lithosphere mostly dip-slip fault-causing quakes of various energy classes take place; i.e., riftogenesis processes dominate. Within the framework of the theory of nonlinear dissipative dynamical systems, these areas are classified as attractor structures of riftogenesis (ASR). ASRs are located in the central part and in the flanks of the BRS, and they form nonlinearity and instability of modern geodynamical and tectonophysical processes in the lithosphere, which are manifested in seismicity of the Baikal Region and Mongolia.

  8. Results of the Baikal Experiment on Observations of oscopic Nonlocal Correlations in Reverse Time

    NASA Astrophysics Data System (ADS)

    Korotaev, S. M.; Serdyuk, V. O.; Kiktenko, E. O.; Budnev, N. M.; Gorohov, J. V.

    Although the general theory oscopic quantum entanglement of is still in its infancy, consideration of the matter in the framework of action-at-a distance electrodynamics predicts for the random dissipative processes observability of the advanced nonlocal correlations (time reversal causality). These correlations were really revealed in our previous experiments with some large-scale heliogeophysical processes as the source ones and the lab detectors as the probe ones. Recently a new experiment has been performing on the base of Baikal Deep Water Neutrino Observatory. The thick water layer is an excellent shield against any local impacts on the detectors. The first annual series 2012/2013 has demonstrated that detector signals respond to the heliogeophysical (external) processes and causal connection of the signals directed downwards: from the Earth surface to the Baikal floor. But this nonlocal connection proved to be in reverse time. In addition advanced nonlocal correlation of the detector signal with the regional source-process: the random component of hydrological activity in the upper layer was revealed and the possibility of its forecast on nonlocal correlations was demonstrated. But the strongest oscopic nonlocal correlations are observed at extremely low frequencies, that is at periods of several months. Therefore the above results should be verified in a longer experiment. We verify them by data of the second annual series 2013/2014 of the Baikal experiment. All the results have been confirmed, although some quantitative parameters of correlations and time reversal causal links turned out different due to nonstationarity of the source-processes. A new result is displaying of the advanced response of nonlocal correlation detector to the earthquake. This opens up the prospect of the earthquake forecast on the new physical principle, although further confirmation in the next events is certainly needed. The continuation of the Baikal experiment with expanded

  9. Results of the Baikal Experiment on Observations of Macroscopic Nonlocal Correlations in Reverse Time

    NASA Astrophysics Data System (ADS)

    Korotaev, S. M.; Serdyuk, V. O.; Kiktenko, E. O.; Budnev, N. M.; Gorohov, J. V.

    Although the general theory macroscopic quantum entanglement of is still in its infancy, consideration of the matter in the framework of action-at-a distance electrodynamics predicts for the random dissipative processes observability of the advanced nonlocal correlations (time reversal causality). These correlations were really revealed in our previous experiments with some large-scale heliogeophysical processes as the source ones and the lab detectors as the probe ones. Recently a new experiment has been performing on the base of Baikal Deep Water Neutrino Observatory. The thick water layer is an excellent shield against any local impacts on the detectors. The first annual series 2012/2013 has demonstrated that detector signals respond to the heliogeophysical (external) processes and causal connection of the signals directed downwards: from the Earth surface to the Baikal floor. But this nonlocal connection proved to be in reverse time. In addition advanced nonlocal correlation of the detector signal with the regional source-process: the random component of hydrological activity in the upper layer was revealed and the possibility of its forecast on nonlocal correlations was demonstrated. But the strongest macroscopic nonlocal correlations are observed at extremely low frequencies, that is at periods of several months. Therefore the above results should be verified in a longer experiment. We verify them by data of the second annual series 2013/2014 of the Baikal experiment. All the results have been confirmed, although some quantitative parameters of correlations and time reversal causal links turned out different due to nonstationarity of the source-processes. A new result is displaying of the advanced response of nonlocal correlation detector to the earthquake. This opens up the prospect of the earthquake forecast on the new physical principle, although further confirmation in the next events is certainly needed. The continuation of the Baikal experiment with

  10. Biological diversity and population history of Middle Holocene hunter-gatherers from the Cis-Baikal region of Siberia.

    PubMed

    Movsesian, Alla A; Bakholdina, Varvara Yu; Pezhemsky, Denis V

    2014-12-01

    In the past decades, prehistoric hunter-gatherers of the Cis-Baikal region has been a subject of multidisciplinary research. In this study, we used nonmetric cranial traits to assess the genetic relationships between various spatial and temporal groups of Cis-Baikal Middle Holocene hunter-gatherers and to reveal genetic continuity between the Cis-Baikal Neolithic-Bronze Age population and modern native Siberians. Cranial series belonging to the bearers of the Early Neolithic Kitoi (n = 72), Late Neolithic Serovo (n = 54), and Early Bronze Glazkovo (n = 98) cultures were examined. Phenotypic differentiation was analyzed by the mean measure of divergence and Nei's genetic distances. Our results revealed several patterns of spatiotemporal biodiversity among the Cis-Baikal Middle Holocene populations, including biological similarity between the Early and Late Neolithic-Bronze Age groups, which suggests that the temporal hiatus between the Early and Late Neolithic does not necessarily imply genetic discontinuity in the region. The following possible scenarios of population history in the Cis-Baikal region are proposed: 1) continuous occupation with outside invasion of new migrant groups in the Late Neolithic and Bronze Age and 2) migration of the Early Neolithic groups to the nearby regions and subsequent return of their descendants to the ancestral territory. A comparison of Cis-Baikal Neolithic populations with modern Siberian natives suggests that the Сis-Baikal region could have been a source area for population expansions into different parts of Siberia in the Neolithic and Bronze Age times. PMID:25176172

  11. Late neoproterozoic igneous complexes of the western Baikal-Muya Belt: Formation stages

    NASA Astrophysics Data System (ADS)

    Fedotova, A. A.; Razumovskiy, A. A.; Khain, E. V.; Anosova, M. O.; Orlova, A. V.

    2014-07-01

    The paper presents new geological, geochemical, and isotopic data on igneous rocks from a thoroughly studied area in the western Baikal-Muya Belt, which is a representative segment of the Neoproterozoic framework of the Siberian Craton. Three rock associations are distinguished in the studied area: granulite-enderbite-charnockite and ultramafic-mafic complexes followed by the latest tonalite-plagiogranitegranite series corresponding to adakite in geochemical characteristics. Tonalites and granites intrude the metamorphic and gabbroic rocks of the Tonky Mys Point, as well as Slyudyanka and Kurlinka intrusions. The tonalites yielded a U-Pb zircon age of 595 ± 5 Ma. The geochronological and geological information indicate that no later than a few tens of Ma after granulite formation they were transferred to the upper lithosphere level. The Sm-Nd isotopic data show that juvenile material occurs in rocks of granitoid series (ɛNd(t) = 3.2-7.1). Ophiolites, island-arc series, eclogites, and molasse sequences have been reviewed as indicators of Neoproterozoic geodynamic settings that existed in the Baikal-Muya Belt. The implications of spatially associated granulites and ultramafic-mafic intrusions, as well as granitoids with adakitic geochemical characteristics for paleogeodynamic reconstructions of the western Baikal-Muya Belt, are discussed together with other structural elements of the Central Asian Belt adjoining the Siberian Platform in the south.

  12. Toxicological assessment of polychlorinated biphenyls and their metabolites in the liver of Baikal seal (Pusa sibirica).

    PubMed

    Nomiyama, Kei; Hirakawa, Shusaku; Eguchi, Akifumi; Kanbara, Chika; Imaeda, Daisuke; Yoo, Jean; Kunisue, Tatsuya; Kim, Eun-Young; Iwata, Hisato; Tanabe, Shinsuke

    2014-11-18

    We have previously reported that high accumulation of dioxins and related compounds induced cytochrome P450 (CYP 1s) isozymes in the liver of wild Baikal seals, implying the enhanced hydroxylation of polychlorinated biphenyls (PCBs). The present study attempted to elucidate the residue concentrations and patterns of PCBs and hydroxylated PCBs (OH-PCBs) in the livers of Baikal seals. The hepatic residue concentrations were used to assess the potential effects of PCBs and OH-PCBs in combination with the analyses of serum thyroid hormones, hepatic mRNA levels, and biochemical markers. The hepatic expression levels of CYP1 genes were positively correlated with the concentration of each OH-PCB congener. This suggests chronic induction of these CYP1 isozymes by exposure to PCBs and hydroxylation of PCBs induced by CYP 1s. Hepatic mRNA expression monitoring using a custom microarray showed that chronic exposure to PCBs and their metabolites alters the gene expression levels related to oxidative stress, iron ion homeostasis, and inflammatory responses. In addition, the concentrations of OH-PCBs were negatively correlated with L-thyroxine (T4) levels and the ratios of 3,3',5-triiodo-L-thyronine (T3)/reverse 3,3',5'-triiodo-L-thyroninee (rT3). These observations imply that Baikal seals contaminated with high levels of OH-PCBs may undergo the disruption of mechanisms related to the formation (or metabolism) of T3 and T4 in the liver. PMID:25343573

  13. Early Proterozoic syn-and postcollision granites in the northern part of the Baikal fold area

    NASA Astrophysics Data System (ADS)

    Larin, A. M.; Sal'Nikova, E. B.; Kotov, A. B.; Makar'ev, L. B.; Yakovleva, S. Z.; Kovach, V. P.

    2006-10-01

    Early Proterozoic granitoids are of a limited occurrence in the Baikal fold area being confined here exclusively to an arcuate belt delineating the outer contour of Baikalides, where rocks of the Early Precambrian basement are exposed. Geochronological and geochemical study of the Kevakta granite massif and Nichatka complex showed that their origin was related with different stages of geological evolution of the Baikal fold area that progressed in diverse geodynamic environments. The Nichatka complex of syncollision granites was emplaced 1908 ± 5 Ma ago, when the Aldan-Olekma microplate collided with the Nechera terrane. Granites of the Kevakta massif (1846 ± 8 Ma) belong to the South Siberian postcollision magmatic belt that developed since ˜1.9 Ga during successive accretion of microplates, continental blocks and island arcs to the Siberian craton. In age and other characteristics, these granites sharply differ from granitoids of the Chuya complex they have been formerly attributed to. Accordingly, it is suggested to divide the former association of granitoids into the Chuya complex proper of diorite-granodiorite association ˜2.02 Ga old (Neymark et al., 1998) with geochemical characteristics of island-arc granitoids and the Chuya-Kodar complex of postcollision S-type granitoids 1.85 Ga old. The Early Proterozoic evolution of the Baikal fold area and junction zone with Aldan shield lasted about 170 m.y. that is comparable with development periods of analogous structures in other regions of the world.

  14. Large mammals from the Upper Neopleistocene reference sections in the Tunka rift valley, southwestern Baikal Region

    NASA Astrophysics Data System (ADS)

    Shchetnikov, A. A.; Klementiev, A. M.; Filinov, I. A.; Semeney, E. Yu.

    2015-03-01

    This work presents the data on new finds of fossil macrotheriofauna in the reference sections of the Upper Neopleistocene sediments in the Tunka rift valley (southwestern Baikal Region). The osteological material of a number of Late Neopleistocene mammals including extinct species rare for the Baikal region such as Crocuta spelaea, Panthera spelaea, and Spirocerus kiakhtensis (?) was directly dated with a radiocarbon (AMS) method. The obtained 14C data (18000-35000 years) allow one to rejuvenate significantly the upper limit of the common age interval of habitat of these animals in southern part of Eastern Siberia. Cave hyena and spiral-horned antelope lived in the Tunka rift valley in the Baikal region in Late Kargino time (37-24 ka), and cave lion survived the maximum in the Sartan cryochron in the region (21-20 ka). The study of collected paleontological collections provides a basis for selection of independent Kargino (MIS 3) faunal assemblages to use them for regional biostratigraphic analysis of Pleistocene deposits. Radiocarbon age dating of samples allows one to attribute confidently all paleofaunal remains available to the second half of the Late Pleistocene.

  15. Osteoarthritis in Siberia's Cis-Baikal: Skeletal indicators of hunter-gatherer adaptation and cultural change.

    PubMed

    Lieverse, Angela R; Weber, Andrzej W; Bazaliiskiy, Vladimir Ivanovich; Goriunova, Olga Ivanovna; Savel'ev, Nikolai Aleksandrovich

    2007-01-01

    This examination of osteoarthritis in Siberia's Cis-Baikal region focuses on the reconstruction of mid-Holocene mobility and activity patterns with particular interest in an alleged fifth millennium BC biocultural hiatus. Five cemetery populations--two representing the pre-hiatus Kitoi culture (6800-4900 BC) and three the post-hiatus Serovo-Glaskovo (4200-1000 BC)-are considered. The objective is to investigate osteoarthritic prevalence and distribution (patterning) within and among these populations in order to reconstruct mobility and activity patterns among the Cis-Baikal foragers, and to test for possible disparities that may reflect differing adaptive strategies. The data reveal that levels of activity remained relatively constant throughout the mid-Holocene but that mobility and specific activity patterns did not. Although results are consistent with the current understanding of distinct Kitoi and Serovo-Glaskovo subsistence regimes, specifically the lower residential mobility and narrower resource base of the former, they also draw attention to adaptive characteristics shared by all occupants of the Cis-Baikal. PMID:17063463

  16. Numerical modeling of the spring thermal bar and pollutant transport in a large lake

    NASA Astrophysics Data System (ADS)

    Tsydenov, Bair O.; Kay, Anthony; Starchenko, Alexander V.

    2016-08-01

    The spring riverine thermal bar phenomenon is investigated numerically on an example of Lake Baikal, and the spread of pollutants coming from the Selenga River is forecast using the 2.5 D non-hydrostatic model in the Boussinesq approximation. This hydrodynamic model takes into account the diurnal variability of the heat fluxes on the lake surface and the effects of wind and the Earth's rotation. The results of numerical modeling show that the variability of the total heat flux over 24 h plays a significant role in the variation of the thermal bar movement rate that contributes to the rapid mixing of impurities entering with river water.

  17. Lake Life.

    ERIC Educational Resources Information Center

    Ohrn, Deborah Gore, Ed.

    1993-01-01

    This quarterly publication of the State Historical Society of Iowa features articles and activities for elementary school students. This summer issue focuses on the topic of lake life. The issue includes the following features: (1) "Where the Lakes Are Map"; (2) "Letter from the Lake"; (3) "Lake People"; (4) "Spirit Lake"; (5) "Lake Manawa"; (6)…

  18. Gas-oil fluids in the formation of travertines in the Baikal rift zone

    NASA Astrophysics Data System (ADS)

    Tatarinov, A. A.; Yalovik, L. I.; Shumilova, T. G.; Kanakin, S. V.

    2016-07-01

    Active participation of gas-oil fluids in the processes of mineral formation and petrogenesis in travertines of the Arshan and Garga hot springs is substantiated. The parageneses of the products of pyrolytic decomposition and oxidation of the gas-oil components of hydrothermal fluids (amorphous bitumen, graphite-like CM, and graphite) with different genetic groups of minerals crystallized in a wide range of P-T conditions were established. Travertines of the Baikal rift zone were formed from multicomponent hydrous-gas-oil fluids by the following basic mechanisms of mineral formation: chemogenic, biogenic, cavitation, fluid pyrometamorphism, and pyrolysis.

  19. A critical review of the development, current hotspots, and future directions of Lake Taihu research from the bibliometrics perspective.

    PubMed

    Zhang, Yunlin; Yao, Xiaolong; Qin, Boqiang

    2016-07-01

    Lake Taihu, as the important drinking water source of the Yangtze River Delta urban agglomeration and the third largest freshwater lake in China, has experienced serious lake eutrophication and water quality deterioration in the past three decades. Growing scientific, political, and public attention has been given to the water quality of Lake Taihu. This study aimed to conduct a comparative quantitative and qualitative analysis of the development, current hotspots, and future directions of Lake Taihu research using a bibliometric analysis of eight well-studied lakes (Lake Taihu, Lake Baikal, Lake Biwa, Lake Erie, Lake Michigan, Lake Ontario, Lake Superior and Lake Victoria) around the world based on the Science Citation Index (SCI) database. A total of 1582 papers discussing Lake Taihu research were published in 322 journals in the past three decades. However, the first paper about Lake Taihu research was not found in the SCI database until 1989, and there were only zero, one, or two papers each year from 1989 to 1995. There had been rapid development in Lake Taihu research since 1996 and a sharp increase in papers since 2005. A keyword analysis showed that "sediment," "eutrophication", "Microcystis aeruginosa", "cyanobacterial blooms", and "remote sensing" were the most frequently used keywords of the study subject. Owing to its significant impact on aquatic ecosystems, a crucial emphasis has been placed on climate change recently. In addition, the future focuses of research directions, including (1) environmental effects of physical processes; (2) nutrient cycles and control and ecosystem responses; (3) cyanobacteria bloom monitoring, causes, forecast and management; (4) eutrophication and climate change interactions; and (5) ecosystem degradation mechanism and ecological practice of lake restoration, are presented based on the keyword analysis. Through multidisciplinary fields (physics, chemistry, and biology) cross and synthesis study of Lake Taihu, the

  20. Genetic features of soils in the basin of Lake Kotokel, the Transbaikal region

    NASA Astrophysics Data System (ADS)

    Balsanova, L. D.; Gyninova, V. B.; Tsybikdorzhiev, Ts. Ts.; Gonchikov, B.-M. N.; Shakhmatova, E. Yu.

    2014-07-01

    The diversity of the soils and the specific features of the pedogenesis in the basin of Lake Kotokel have been studied. The specificity of the pedogenesis and soil cover patterns in the lake basin are controlled by the altitudinal zonation, the diversity of parent materials, and the influence of air masses from Lake Baikal. Gray metamorphic soils and raw-humus burozems developed under taiga vegetation in the mountains predominate in the basin of Lake Kotokel. The coastal landscapes and river valleys are occupied by swampy and meadow alluvial soils. The genetic features of the major soils have been characterized on the basis of field descriptions, laboratory data, and special macro- and micromorphological studies.

  1. An exposed slab window margin: the eastern part of the Neoproterozoic Baikal-Muya belt, Russia

    NASA Astrophysics Data System (ADS)

    Fedotova, A.; Khain, E.; Razumovskiy, A.; Anosova, M.; Orlova, A.

    2012-04-01

    A series of dykes and small laccolith-type magmatic bodies of tonalite, trondhjemite, granodiorite and granites marks the final stage in the geological history of the Baikal-Muya belt in an adjacent area of the Siberian craton. These bodies intrude granulite-enderbite-charnokite complex, as well as troctolite Tonkiy Mys massif. These high-silica (SiO2N56%), high alumina (Al2O3>15%), pyroxene or and amphibole bearing granitoids, with Na2O>4%, high Sr (>400 ppm), low Y (<7 ppm), high Sr/Y(>35), low Yb (<1), and are geochemically similar to adakites. The same structural position was defined for granites showing K2O=4.5% and K2O/Na2O=1,4. The tonalites of this complex collected f yielded the U-Pb zircon age of 591±3 Ma (LA ICP-MS data). Previously obtained age estimate for the enderbites is 617±5 Ma [Amelin et al., 2000]. Three samples of enderbites and gneisse provided U-Pb zircon ages fallen into the time span between 603-620 Ma. The Slyudinskii massif of high-Ti gabbronorites spatially related to the enderbite-granulite complex was crystallized 618±61 Ma ago [Makrygina et al., 1993]. The published data obtained for the massif (585±22 Ma [Makrygina et al., 1993]) show that troctolite-gabbro massifs crystallized simultaneously or insignificantly later than granulite-enderbite complex at upper levels of the lithosphere. Rocks of these massifs and the gabbro-granulite-enderbite series formed at lower levels have been joined during a stage of tectonic activity and intruded by adakites 591±3 Ma ago. High tectonic activity also reflected in deposition of the coarse clastics occurred in a lower part of Kholodnenskaya suite and contemporary formations. The following events can be reconstructed for the eastern part of the Baikal-Muya belt. Formation of the heterogeneous accretional orogenic structure (tectonic collage), with ophiolites and remnants of earlier formed Neoproterozoic island arcs and related complexes [Izokh, 1998; Rytsk, 2001; Shatskii et al., 1996], was

  2. Seismic and electrical work at rivers and lakes of Siberia

    NASA Astrophysics Data System (ADS)

    Seleznev, V. S.; Soloviev, V. M.; Liseikin, A. V.; Sigonin, P.

    2013-05-01

    In West and East Siberia a great deal of rivers and big lakes are situated. For oil and gas exploration these places hold much promise. It is very difficult to carry out seismic work in these regions, when temperature is fall down below 40 degrees centigrade. It is necessary to pave ways for technical equipment, to organize shooting operations in some cases, that harming ecology of investigated regions. It is well-known, that at seas and big reservoirs seismic works are carried out with use of air guns as sources and floating or ground cables as receivers. There is a special interest to carry out jointly processing and interpretation of seismic survey and electrical data. We should learn how to carry out such researches at rivers, developed a special combined technology on river seismic and electrical works carrying out. Geophysical Survey SB RAS has been carried out seismic and electrical works at rivers and reservoirs of Siberia for more then 20 years. We had to work in conditions, when depth of a reservoir was more then 10 meters or less then 1 meter. It was necessary to work out or adapt some floating equipment, to create air-guns working on light depths ("Malysh", "Sibiryak"), to create new recording equipment (seismic and electrical variants of "Baikal" equipment) for carrying out work in such conditions. There are presented the results of seismic researches, carried out in the Lake Baikal, Lake Teletskoe. For the first time it was determined, that the depth of sedimentary cover under Lake Baikal exceeds 14 km. On demands of government and private companies we carried out river works in Common-depth-point method at such rivers as: Ob, Volga, Enisey, Vakh, Lena, Kirenga, Nizhnya Tunguska. Comparison of results got at river profiles with surface ones, crossing the river, showed in difficult surface conditions (central part of the River Lena, the Nizhnya Tunguska) river seismic sections are better then surface sections. It is connected with the fact, that

  3. The debris flows risk in south Baikal region of Russia - high losses or low risk

    NASA Astrophysics Data System (ADS)

    Shnyparkov, Aleksandr; Baburin, Vyacheslav; Sokratov, Sergey; Khismatullin, Timur

    2016-04-01

    Debris flows were previously not considered as frequent and disastrous natural hazards in the south Baikal region of Russia. The historical records list only two events resulting in reported serious economical losses in here (1903 and 1962). However, an event of June 2014 (Arshan settlement destruction) raised discussion on the debris flow danger and necessity of expensive mitigation measures in the regions. That is why debris flow risk was estimated for the region as a whole with the purpose to calculate the necessary investments into the debris flows protection. The presented results suggests that the degree of debris flows danger is still at least twice lower than is such regions as the North Caucasus in Russia and single events should not be considered as a main basis for regional land use planning.

  4. Arshan palaeoseismic feature of the Tunka fault (Baikal rift zone, Russia)

    NASA Astrophysics Data System (ADS)

    Smekalin, Oleg P.; Shchetnikov, Alexander A.; White, Dustin

    2013-01-01

    The traditional concept of the rift development of flank depressions in the Baikal rift zone is now doubted in view of some indicators for compression deformations identified by the seismogeological and geodetic methods. Besides, the paleoseismological investigations revealed seismogenic strike-slips and reverse faults in the Tunka fault zone that is a major structure-controlling element of the Tunka rift depression. However, a detailed study of the upslope-facing scarp in the Arshan paleoseismogenic structure zone has shown that its formation might be due to rift mechanism of basin formation. Age estimation has been made for the previously unknown pre-historic earthquake whose epicentral area coincides with the western flank of the Arshan paleoseismogenic structure. Judging from previously determined ages of paleoearthquakes, the mean recurrence period for faulting events on the central Tunka fault is 2780-3440 years.

  5. Morphotectonic evolution of two depressions at the southern border of the Baikal rift system

    NASA Astrophysics Data System (ADS)

    Vogt, Henri; Vogt, Thea

    2007-05-01

    Detailed study of two dry depressions in the Baikal rift system: the E-W Khoito Ghol-Tunka-Bistraya depression and the SW-NE Gusinoje-Ivolga depression, aims to provide a better understanding of tectonic control on the intershoulder relief evolution after the rift opened. Both depressions are grabens and both feature a suite of 10-20 km-wide basins alternating with more or less massive highs. Field and laboratory analysis shows that this pattern is of recent tectonic origin and that local breaking-up and subsidence followed the general sinking which originally formed the grabens. The subsidence belts seem to have gradually shifted north and northeastwards. Geomorphological analysis reveals that in both depressions the highs are remnants of a former pediment which was broken up. The young basins display numerous relevant hydrographic anomalies of the secondary channels and a general water-logging. They also suggest that the subsidence belts have gradually shifted north-and northeastwards. In the Gusinoje-Ivolga depression evidence was found of a Plio-Pleistocene river course, parallel to the Selenga river, which was later dismantled by the breaking-up. This depression, parallel to the Baikal rift and belonging to the Mesozoic system of grabens in the Caledonian fold belt, seems to have been included into the general system of rifts during the Pliocene tectonic phase. As for the main hydrographic axes, the Selenga river was set on a Palaeogene-age planation surface before the first tectonic phase and kept its original course. The Irkut river flowed in the Khoito Gol-Tunka-Bistraya depression after the first tectonic phase and was not affected by the later breaking-up. In contrast, the secondary drainage network is largely discordant. Despite their different geotectonic contexts, the two depressions show a similar development of relief pattern ,which poses the question of the style of rift dynamics after the main Pliocene tectonic phase.

  6. Integrated perspectives on geological and biological dynamics in ancient Lake Ohrid

    NASA Astrophysics Data System (ADS)

    Wagner, B.; Wilke, T.; Francke, A.; Leicher, N.; Krastel, S.; Zanchetta, G.; Sulpizio, R.; Sadori, L.; Just, J.; Levkov, Z.; Wonik, T.; Vogel, H.; Wagner-Cremer, F.

    2015-12-01

    Lake Ohrid on the Balkan Peninsula is, along with lakes Baikal and Elgygytgyn in Russia and Lake Bosumtwi in Ghana, one of the very few lakes in the world that provides a continuous and high resolution record of environmental change of >1 Ma. With >300 endemic taxa, Lake Ohrid has the fourth highest degree of endemism in the world, being exceeded only by lakes Baikal, Tanganyika and Malawi. The combination of its long existence and high endemism makes Lake Ohrid a unique target to study the drivers of speciation and endemism. For this purpose, a 569 m long sediment sequence was recovered from the central part of the lake in spring 2013 within the scope of the International Continental Scientific Drilling Program (ICDP) and the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) project. Here, we present the results to date of analysis of the upper 248 m of this sequence, which covers the last ca. 640 ka according to an age model based on tephrostratigraphy as well as tuning of in situ physical and biogeochemical proxy data to orbital parameters and to the global benthic isotope stack. The sedimentological, physical, and geochemical data from the sediment sequence indicate changes in primary productivity, water column stratification, and water depth of the lake, and in weathering and erosion processes in the catchment. These changes can be clearly correlated with the intensity of glacial and interglacial periods as well as stadials and interstadials. However, paleontological and molecular clock analyses indicate that these changes and also the tephra deposition from eruptions of Italian volcanoes apparently did not lead to significant extinction events in the endemic species community. The lack of such catastrophic extinction events is probably due to the buffering capacity of the deep lake, possibly enhanced by the continuous existence of subaquatic karst springs with relatively stable habitats in the surroundings. This would enable the

  7. Mapping of the concentration of carbonaceous gases and fluorescent characteristics in the surface water of Southern Baikal

    NASA Astrophysics Data System (ADS)

    Pestunov, Dmitrii A.; Shamrin, Artem M.; Shmargunov, Vladimir P.; Domysheva, Valentina M.; Sakirko, Maria V.; Panchenko, Mikhail V.

    2015-11-01

    All our many-year studies of the gas-exchange processes were carried out at one observation site (BALO) in the littoral of Southern Baikal. Thus, the question about applicability of conclusions and estimates based on these data to the entire littoral zone inevitably arises. In 2014, we succeeded for the first time in organizing the combined research campaign for detailed mapping of the spatial variability of water characteristics in general for the littoral of southern Baikal. The spatial partial distribution of biogenic elements and the pressure of carbon dioxide and methane in the atmospheric surface layer and the surface water layer were studied in August 5-11 of 2014 from onboard of I.D. Papanin Research Vessel (RV). These studies covered, in section, the entire water area of the southern Baikal. The fluorescent characteristics, concentration of biogenic elements, partial pressure of carbon dioxide and methane in the surface water layer and the atmospheric surface layer were determined there. The continuous measurements of carbon dioxide and methane in the surface water and in the atmosphere in the course of the vessel were conducted by a mobile shipborne system, which was complemented with the flow-through fluorimeter. It has been found that the main features of fluxes and the value of dPg, as well as fluorescent characteristics are in a good agreement with the results of many-year measurements obtained in the BALO Observatory for the summer period.

  8. The changes of glaciers on northern Baikal ridges over 50 years using in-situ and remotely sensed observations

    NASA Astrophysics Data System (ADS)

    Ivanov, Egor; Alexander, Kitov

    2013-04-01

    All the glaciers lying over the Baikalsky and Barguzinsky ridges of Northern Baikal are small. They are located in hard-to-reach regions both for In-situ such and for remotely sensed observations. A researcher can reach glaciers only by using special alpine equipment. The deep ruggedness of hollows and the being of glaciers in the shade over a period of significant time prevent from remotely sensed observations. The Glaciers of Baikalsky ridge are not registered in the catalogue of the Eurasia glaciers since there are no data about the glaciers in the catalogue of the glaciers of USSR. In result of our expedition works and the analyzing of satellite photograph it was determined that the largest cirque glacier- Cherskogo sufficiently stable. Its retreat has been insignificantly in over 50 years - from 0.446 to 0.407 sq. km, id est on 8,7 %. The glaciers of Barguzinsky ridge are very poorly explored. IG SB RAS in 2011 year for the first time completed the expedition with the object of inventory of these ridge glaciers. This region is extremely difficult to approach. The space survey of ultrahigh resolution for the study area (0.5 m) was ordered before the start of the expedition. Also the accessible archive data of Landsat resolution by 15-30 meters have been received. The comparison of cartographical, distance and expedition data show essential retreat of most of glaciers and its degradation from cirque to slope glaciers. Discovered snow-glacial formations can be divided on 3 main groups: 1 -real glaciers; 2 - slope pendent glacier remains; 3 - permanent snow patches. The region is interesting because there practically are all the forms of little glaciations. In addition it can be observed not only glacier's degradation but their origins too. In the favorable year conditions the snow patches are increased with occupying of the basic of cirque bed and form the ice core and continue the formation of the cirque. The second group of glaciers has actually been reserved

  9. Spatial changes of seismic attenuation and multiscale geological heterogeneity in the Baikal rift and surroundings from analysis of coda waves

    NASA Astrophysics Data System (ADS)

    Dobrynina, Anna A.; Sankov, Vladimir A.; Chechelnitsky, Vladimir V.; Déverchère, Jacques

    2016-04-01

    The Baikal rift system is undergoing an active tectonic deformation expressed by a high level of seismic activity. This deformation leads to physical and mechanical changes of crustal properties which can be investigated by the seismic quality factor and its frequency dependence. Using a single backscattering model, a seismic quality-factor (QC), a frequency parameter (n) and an attenuation coefficient (δ) have been estimated by analyzing coda waves of 274 local earthquakes of the Baikal rift system for nineteen lapse time windows (W) from 10 to 100 s every 5 s and for six central frequencies (0.3, 0.75, 1.5, 3, 6 and 12 Hz). The average QC value increases with the frequency and lapse time window from 46 ± 52 (at 0.75 Hz) to 502 ± 109 (at 12 Hz) for W = 10 s and from 114 ± 49 (at 0.3 Hz) to 1865 ± 679 (at 12 Hz) for W = 100 s. The values of QC(f) and δ were estimated for the whole Baikal rift system and for separate tectonic blocks: the stable Siberian Platform, main rift basins, spurs and uplifts. Along the rift system, the Q0-value (QC-factor at the frequency f = 1 Hz) varies within 72-109 and the frequency parameter n ranges from 0.87 to 1.22, whereas Q0 is 134 and n is 0.48 for the stable Siberian Platform. Vertical variations of attenuation reveal that sharp changes of δ and n are confined to the velocity discontinuities. The comparison of lateral variations of seismic wave attenuation and geological and geophysical characteristics of the Baikal rift system shows that attenuation is correlated with both seismic activity and heat flow and in a lesser degree with the surface fault density and the age of the crust. Seismic wave attenuation found across the main shear zones of the south-western Baikal rift (Main Sayan strike-slip fault zone and Tunka, Obruchev and Primorsky normal faults) is increased by more than 25-60% compared to the neighboring areas.

  10. Granitoids of different geodynamic settings of Baikal region (Russia) their geochemical evolution and origin

    NASA Astrophysics Data System (ADS)

    Antipin, Viktor; Sheptyakova, Natalia

    2016-04-01

    In the southern folded framing of the Siberian craton the granitoid magmatism of different ages involves batholiths, small low-depth intrusions and intrusion-dyke belts with diverse mineral and geochemical characteristics of rocks. Granitoid formation could be related to the Early Paleozoic collision stage and intra-plate magmatism of the Late Paleozoic age of the geologic development of Baikal area. The Early Paleozoic granitoids of Khamar-Daban Ridge and Olkhon region revealed their closeness in age and composition. They were referred to syncollision S-type formations derived from gneiss-schistose substratum of metamorphic sequences. The magmatic rocks were classified into various geochemical types comprising formations of normal Na-alkalinity (migmatites and plagiogranites), calc-alkaline and subalkaline (K-Na granitoids, granosyenites and quartz syenites) series. It is significant, that plagiomigmatites and plagiogranites in all elements repeat the shape of the chart of normalized contents marked for trend of K-Na granitoids, but at considerably lower level of concentrations of all elements. This general pattern of element distribution might indicate similar anatectic origin of both granitoid types, but from crustal substrata distinguished by composition and geochemical features. Comparative geochemical analysis pointed out that the source of melts of the Early Paleozoic granitoids of the Olkhon (505-477 Ma) and Khamar-Daban (516-490 Ma) complexes of the Baikal region could be the crustal substratum, which is obviously the criterion for their formation in the collisional geodynamic setting. Using the Late Paleozoic subalkaline magmatism proceeding at the Khamar-Daban Range (Khonzurtay pluton, 331 Ma) as an example, it was found that the formation of monzodiorite-syenite-leucogranite series was considerably contributed by the processes of hybridism and assimilation through mixing of the upper mantle basaltoid magma derived melts of granitic composition. The

  11. Lake Powell

    Atmospheric Science Data Center

    2014-05-15

    article title:  Lake Powell     View Larger Image ... (14.42 mb)   This true-color image over Lake Powell was acquired by Multi-angle Imaging SpectroRadiometer (MISR) in late March 2000. Lake Powell was formed with the construction of the Glen Canyon Dam in 1963, on the ...

  12. CONNECTICUT LAKES

    EPA Science Inventory

    This is a 1:24,000-scale datalayer of named lakes in Connecticut. It is a polygon Shapefile that includes all lakes that are named on the U.S. Geologicial Survey (USGS) 7½ minute topographic quadrangle maps that cover the State of Connecticut, plus other officially named lakes i...

  13. Lake Eyre

    Atmospheric Science Data Center

    2013-04-16

    ...   View Larger Image Lake Eyre is a large salt lake situated between two deserts in one of Australia's driest regions. ... the effect of sunglint at the nadir camera view angle. Dry, salt encrusted parts of the lake appear bright white or gray. Purple areas have ...

  14. Semiarid landscapes response to Aeolian processes during Holocene in Baikal Region

    NASA Astrophysics Data System (ADS)

    Dan'ko, Lidia; Opekunova, Marina

    2010-05-01

    Arid and semiarid landscapes play a significant role in global climate, biogeochemical, and hydrological processes. Regional analysis of the past aeolian processes is essential for improve our understanding of how various landscape and ecosystems responded to climate change in the past. Our investigation presents details on sand dunes and on loess-like sediments. The study areas are situated in the northern part of Baikal Region (Eastern Siberia). In its depressions, the so-called Barguzinskaya and Tunkinskaya Valley surrounded mountain ranges local dunefieds and loess-like sediments have developed. Present climate in the study areas is continental, characterized by low precipitation(mean annual 250-450 mm) and wide annual range of temperature. Field investigations indicate that the Holocene deposits of the Barguzinskaya and Tunkinskaya Valley are sealed the pedo-sedimentary interface. The analytical results suggest that one's represents a changeover from intensified soil formation to accelerated aeolian dust accumulation. The original content of calcium carbonate and gypsum at the base of some sections of loess-like sediments indicates the aeolian origin of these sediments. In whole, the soil horizons are a proof for humid phases. The change was forced by climatic aridity. Absolute dating of the organogenic components of soils (14C) indicate the age positions of the arid and humid climate phases. Our results indicate not only 1-4 long-time episodes of aeolian dust accumulation during the Holocene, but shot-time aeolian accumulation episodes, that were specific for Late Holocene. For example, in the Tunkinskaya Valley the Late Holocene soil formation replaced by aeolian deposit at 1700 - 1900, 800 and 200-250 years ago, in the Barguzinskaya Valley - about 3100 - 2900, 2300 and 600 years ago. It can be concluded that a periodical formation of the aeolian deposits in the semiarid landscapes during Holocene can be postulated. Aeolian and loess-like sediments of the

  15. Early Hercynides of the Baikal-Vitim Fold System, western Transbaikal region

    NASA Astrophysics Data System (ADS)

    Minina, O. R.; Doronina, N. A.; Nekrasov, G. E.; Vetluzhskikh, L. I.; Lantseva, V. S.; Aristov, V. A.; Naugol'nykh, S. V.; Kurilenko, A. V.; Khodyreva, E. V.

    2016-05-01

    New data on the composition, age, structure, and geodynamic settings of the Upper Silurian-lower Middle Carboniferous rocks in the Baikal-Vitim Fold System (BVFS) are reported. These rocks make up the Early Hercynian structural stage of the BVFS, within which the Uda-Vitim, Vitimkan-Tsipa, and Turka-Kurba lithotectonic zones are recognized. The Early Hercynian stage combines rocks of two stratigraphic levels: Upper Silurian-Upper Devonian (S2-D3) and Upper-Devonian-Middle Carboniferous (D3-C2 1). On the basis of lithostratigraphic and spatiotemporal relationships between sedimentary and volcanic-sedimentary complexes of the Early Hercynian stage three formations are identified, which characterize the main tectonic regimes of the early half of the Late Paleozoic. It has been established that a common paleobasin that evolved through consecutively changing geodynamic settings at the passive and active continental margins existed in the Silurian (?)-early Middle Carboniferous in the northeastern part (in present-day coordinates) of the western Transbaikal region.

  16. Coexistence of structure I and II gas hydrates in Lake Baikal suggesting gas sources from microbial and thermogenic origin

    NASA Astrophysics Data System (ADS)

    Kida, Masato; Khlystov, Oleg; Zemskaya, Tamara; Takahashi, Nobuo; Minami, Hirotsugu; Sakagami, Hirotoshi; Krylov, Alexey; Hachikubo, Akihiro; Yamashita, Satoshi; Shoji, Hitoshi; Poort, Jeffrey; Naudts, Lieven

    2006-12-01

    We report the field observation of hydrate deposits of different crystal structures in the same cores of a mud volcano in the Kukuy Canyon. We link those deposits to chemical fractionation during gas hydrate crystallization. Gas composition and crystallographic analyses of hydrate samples reveal involvement of two distinct gas source types in gas hydrate formation at present or in the past: microbial (methane) and thermogenic (methane and ethane) gas types. The clathrate structure II, observed for the first time in fresh water sediments, is believed to be formed by higher mixing of thermogenic gas.

  17. Neoproterozoic ophiolite and related high-grade rocks of the Baikal-Muya belt, Siberia: Geochronology and geodynamic implications

    NASA Astrophysics Data System (ADS)

    Kröner, A.; Fedotova, A. A.; Khain, E. V.; Razumovskiy, A. A.; Orlova, A. V.; Anosova, M. O.; Perelyaev, V. I.; Nekrasov, G. E.; Liu, D. Y.

    2015-11-01

    We report zircon for from ophiolitic and high-grade rocks of the Neoproterozoic Baikal-Muya belt of Siberia that occupies an arc-shaped area on the southeastern margin of the Siberian craton. It consists of arc-related plutonic, metavolcanic and metasedimentary rocks as well as fragmented ophiolites and high-grade metamorphic assemblages. Magmatic zircons from two plagiogranite dyke samples of the Mamakan ophiolite complex in the Sredne-Mamakan massif of the eastern Baikal-Muya belt yielded similar and concordant SHRIMP mean 206Pb/238U ages of 640.0 ± 4.1 and 650 ± 6 Ma, respectively, that reflect the time of dyke emplacement and from which we suggest an age of ca. 645 Ma as the most likely time of ophiolite formation. Enderbitic gneisses of the North Baikal area, in the western part of the Baikal-Muya belt, contain complex zircon populations that reflect variable recrystallization, Pb-loss and metamorphic overgrowth during granulite-facies metamorphism. LA-ICP-MS dating of these zircons yielded inconclusive results that led us to undertake a detailed study of cathodoluminescence images combined with U-Pb SHRIMP dating. Well-preserved magmatic domains in zircons from enderbite sample 2821 yielded concordant results with a mean 206Pb/238U age of 640 ± 5 Ma, slightly higher but broadly comparable with the data obtained by LA-ICP-MS. The zircon populations of two more enderbitic gneiss samples are more complex, and their LA-ICP-MS data constitute broad swaths along concordia between ca. 840 and 600 Ma, reflecting two end-member isotopic components, namely an igneous crystallization event at ca. 800 Ma and a Pb-loss and recrystallization event at ca. 600 Ma. SHRIMP analyses of magmatic zircon domains of these samples yielded concordant data with identical mean 206Pb/238U ages of 826 ± 7.5 Ma and 826 ± 8 Ma, respectively, whereas low-U metamorphic rims crystallized at 640 ± 7 Ma. Newly crystallized ball-round metamorphic zircons in one sample produced a mean 206Pb

  18. Drift dives and prolonged surfacing periods in Baikal seals: resting strategies in open waters?

    PubMed

    Watanabe, Yuuki Y; Baranov, Eugene A; Miyazaki, Nobuyuki

    2015-09-01

    Many pinnipeds frequently rest on land or ice, but some species remain in open waters for weeks or months, raising the question of how they rest. A unique type of dive, called drift dives, has been reported for several pinnipeds with suggested functions of rest, food processing and predator avoidance. Prolonged surfacing periods have also been observed in captive seals and are thought to aid food processing. However, information from other species in a different environment would be required to better understand the nature and function of this behavior. In this study, we attached multi-sensor tags to Baikal seals Pusa sibirica, a rare, freshwater species that has no aquatic predators and few resting grounds during the ice-free season. The seals exhibited repeated drift dives (mean depth, 116 m; duration, 10.1 min) in the daytime and prolonged periods at the surface (mean duration, 1.3 h) mainly around dawn. Drift dives and prolonged surfacing periods were temporally associated and observed between a series of foraging dives, suggesting a similar function, i.e. a combination of resting and food processing. The maximum durations of both drift and foraging dives were 15.4 min, close to the aerobic dive limit of this species; therefore, metabolic rates might not be significantly depressed during drift dives, further supporting the function of food processing rather than purely resting. Our results also show that drift diving can occur in a predator-free environment, and thus predator avoidance is not a general explanation of drift dives in pinnipeds. PMID:26139663

  19. Evidence for small-scale mantle convection in the upper mantle beneath the Baikal rift zone

    NASA Astrophysics Data System (ADS)

    Gao, Stephen S.; Liu, Kelly H.; Davis, Paul M.; Slack, Phillip D.; Zorin, Yuliy A.; Mordvinova, Valentina V.; Kozhevnikov, Vladimir M.

    2003-04-01

    Inversion of teleseismic P wave travel time residuals collected along a 1280-km-long profile traversing the Baikal rift zone (BRZ) reveals the existence of an upwarped lithosphere/asthenosphere interface, which causes a travel time delay of about 1 s at the rift axis ("central high"). An area with early arrivals relative to the stable Siberian platform of up to 0.5 s is observed on each side of the rift, about 200 km from the rift axis ("flank lows"). While the location of the central high is approximately fixed in the vicinity of the rift axis, those of the flank lows vary as much as 200 km with the azimuth of the arriving rays. We use three techniques to invert the travel time residuals for velocity anomalies beneath the profile. Two of the techniques assume an isotropic velocity structure, and one of them considers a transversely isotropic velocity model with a vertical axis of symmetry. We use independent geophysical observations such as gravity, active source seismic exploration, and crustal thickness measurements to compare the applicability of the models. Other types of geophysical measurements suggest that the model involving transverse isotropy is a plausible one, which suggests that the central high and flank lows are caused by the combined effects of an upwarped asthenosphere with a 2.5% lateral velocity reduction, and a velocity increase due to transverse isotropy with a vertical axis of symmetry. We consider the anisotropy to be the result of the vertical component of a lithosphere/asthenosphere small-scale mantle convection system that is associated with the rifting.

  20. Numerical reconstruction of Late-Cenosoic evolution of normal-fault scarps in Baikal Rift Zone

    NASA Astrophysics Data System (ADS)

    Byzov, Leonid; San'kov, Vladimir

    2014-05-01

    Numerical landscape development modeling has recently become a popular tool in geo-logic and geomorphic investigations. We employed this technique to reconstruct Late-Cenosoic evolution of Baikal Rift Zone mountains. The objects of research were Barguzin Range and Svyatoy Nos Upland. These structures are formed under conditions of crustal extension and bounded by active normal faults. In our experiments we used instruments, engineered by Greg Tucker (University of Colo-rado) - CHILD (Channel-Hillslope Integrated Landscape Development) and 'Bedrock Fault Scarp'. First program allowed constructing the complex landscape model considering tectonic uplift, fluvial and hillslope processes; second program is used for more accurate simulating of triangular facet evolution. In general, our experiments consisted in testing of tectonic parameters, and climatic char-acteristic, erosion and diffusion properties, hydraulic geometry were practically constant except for some special runs. Numerous experiments, with various scenarios of development, showed that Barguzin range and Svyatoy Nos Upland has many common features. These structures characterized by internal differentiation, which appear in height and shape of slopes. At the same time, individual segments of these objects are very similar - this conclusion refers to most developing parts, with pronounced facets and V-shaped valleys. Accordingly modelling, these landscapes are in a steady state and are undergoing a uplift with rate 0,4 mm/yr since Early Pliocene (this solution accords with AFT-dating). Lower segments of Barguzin Range and Svyatoy Nos Upland also have some general fea-tures, but the reasons of such similarity probably are different. In particular, southern segment of Svyatoy Nos Upland, which characterized by relative high slope with very weak incision, may be formed as result very rapid fault movement or catastrophic landslide. On the other hand, a lower segment of Barguzin Range (Ulun segment, for example

  1. Lake Constance

    Atmospheric Science Data Center

    2013-04-17

    ... Swiss shores of Lake Constance at the town of Rorschach. Eutrophication, or the process of nutrient enrichment, is rapidly accelerated ... of the value of Lake Constance, efforts to mitigate eutrophication were initiated in the 1970's. MISR was built and is managed ...

  2. LAKE FORK

    EPA Science Inventory

    The Lake Fork of the Arkansas River Watershed has been adversely affected through mining, water diversion and storage projects, grazing, logging, and other human influences over the past 120 years. It is the goals of the LFWWG to improve the health of Lake fork by addressing th...

  3. Blood levels of polychlorinated biphenyls and their hydroxylated metabolites in Baikal seals (Pusa sibirica): emphasis on interspecies comparison, gender difference and association with blood thyroid hormone levels.

    PubMed

    Imaeda, Daisuke; Nomiyama, Kei; Kunisue, Tatsuya; Iwata, Hisato; Tsydenova, Oyuna; Amano, Masao; Petrov, Evgeny A; Batoev, Valeriy B; Tanabe, Shinsuke

    2014-11-01

    We have previously demonstrated that Baikal seals (Pusa sibirica) are still being exposed to polychlorinated biphenyls (PCBs), and the population is at risk. In the present study, we measured the residue levels of PCBs and their hydroxylated metabolites (OH-PCBs) in the blood of Baikal seals and assessed the impact of OH-PCBs on the thyroid function. Blood concentrations of PCBs and OH-PCBs were in the range of 2.8-130 ng g(-1)wet wt. and 0.71-4.6 ng g(-1)wetwt., respectively. Concentrations of higher-chlorinated OH-PCBs (hexa- to octa-PCBs) were more than 70% to total OH-PCB concentrations, indicating Baikal seals are mostly risked by higher-chlorinated OH-PCBs. High levels of 4OH-CB146 and 4OH-CB187 and low levels of 4OH-CB107/4'OH-CB108 found in Baikal seals were different from those in other phocidae species, suggesting the unique drug-metabolizing enzyme activities and/or contamination sources in this species. Concentrations of some OH-PCBs in males were significantly higher than those in females. These results suggest that these isomers may be preferentially transferred from mother to pup via cord blood. However, concentrations of almost all the isomers were not significantly correlated with the levels of blood total T3 and T4, implying less impact of PCB-related compounds on the thyroid hormone circulation. PMID:25113177

  4. Tectonic Features of the Barguzin Depression of the Baikal Rift Zone Using Computer Interpretation of Electrical Soundings Data

    NASA Astrophysics Data System (ADS)

    Nevedrova, N.; Epov, M.; Sanchaa, A.

    2003-12-01

    In 1950s of the twentieth century, extensive geophysical prospecting was carried out in the region of Baikal Rift Zone with the aim to investigate the deep depression structure. The basic method of geophysical exploration was vertical electrical sounding (VES). At that time, the sufficiently complicated structure of the section gave no way of determining the main parameters of separate depositional sequences. With the development of computer techniques it has become the possibility to interpret these complicated data of electrical exploration at the new qualitative level by using programs of mathematical modelling and inversion. At the first stage, interpretation of electrical prospecting data was executed based on solution of the inverse problem within the limit of the horizontally-layered model using the SONET program complex. Moreover, by using both 2D modelling and inversion, it is possible to refine geoelectrical parameters and to conclude that entirely acceptable results can be obtained using 1D inversion. The final results reflect the detailed deep depression structure and it tectonic features. Tectonically active zone with multiple ruptures, which form complicated block structures as in the sedimentary cover so in the base, are under investigation.The sedimentary cover is as thick as 2.5 km according to results of computer interpretation. Fractured zones exhibit the areas with decreased rock resistivity. Reconstruction of a detailed tectonic structure of Barguzin depressions allow better understanding peculiarities of geodynamic processes for the Baikal rift zone in general and for depression in particular.

  5. Variability of the atmospheric turbulence in the region lake of Baykal

    NASA Astrophysics Data System (ADS)

    Botygina, N. N.; Kopylov, E. A.; Lukin, V. P.; Kovadlo, P. G.; Shihovcev, A. Yu.

    2015-11-01

    The estimations of the fried parameter according to micrometeorological and optical measurements in the atmospheric surface layer in the area of lake Baikal, Baikal astrophysical Observatory. According to the archive of NCEP/NCAR Reanalysis data obtained vertical distribution of temperature pulsations, and revealed the most pronounced atmospheric layers with high turbulence. A comparison of astronomical conditions vision in winter and in summer. By the registration of optical radiation of the Sun with telescopes, ground-based there is a need to compensate for the effects of atmospheric turbulence. Atmospheric turbulence reduces the angular resolution of the observed objects and distorts the structure of the obtained images. To improve image quality, and ideally closer to angular resolution, limited only by diffraction, it is necessary to implement and use adaptive optics system. The specificity of image correction using adaptive optics is that it is necessary not only to compensate for the random jitter of the image as a whole, but also adjust the geometry of the individual parts of the image. Evaluation of atmospheric radius of coherence (Fried parameter) are of interest not only for site-testing research space, but also are the basis for the efficient operation of adaptive optical systems 1 .

  6. Search for neutrino emission from relic dark matter in the sun with the Baikal NT200 detector

    NASA Astrophysics Data System (ADS)

    Avrorin, A. D.; Avrorin, A. V.; Aynutdinov, V. M.; Bannasch, R.; Belolaptikov, I. A.; Bogorodsky, D. Yu.; Brudanin, V. B.; Budnev, N. M.; Danilchenko, I. A.; Demidov, S. V.; Domogatsky, G. V.; Doroshenko, A. A.; Dyachok, A. N.; Dzhilkibaev, Zh.-A. M.; Fialkovsky, S. V.; Gafarov, A. R.; Gaponenko, O. N.; Golubkov, K. V.; Gress, T. I.; Honz, Z.; Kebkal, K. G.; Kebkal, O. G.; Konischev, K. V.; Konstantinov, E. N.; Korobchenko, A. V.; Koshechkin, A. P.; Koshel, F. K.; Kozhin, A. V.; Kulepov, V. F.; Kuleshov, D. A.; Ljashuk, V. I.; Milenin, M. B.; Mirgazov, R. A.; Osipova, E. R.; Panfilov, A. I.; Pan'kov, L. V.; Perevalov, A. A.; Pliskovsky, E. N.; Poleschuk, V. A.; Rozanov, M. I.; Rubtzov, V. F.; Rjabov, E. V.; Shaybonov, B. A.; Sheifler, A. A.; Shkurihin, A. V.; Smagina, A. A.; Suvorova, O. V.; Tarashansky, B. A.; Yakovlev, S. A.; Zagorodnikov, A. V.; Zhukov, V. A.; Zurbanov, V. L.

    2015-03-01

    We have analyzed a data set taken over 2.76 years live time with the Baikal neutrino telescope NT200. The goal of the analysis is to search for neutrinos from dark matter annihilation in the center of the Sun. Apart from the conventional annihilation channels b b bar , W+W- and τ+τ- we consider also the annihilation of dark matter particles into monochromatic neutrinos. From the absence of any excess of events from the direction of the Sun over the expected background, we derive 90% upper limits on the fluxes of muons and muon neutrinos from the Sun, as well as on the elastic cross sections of dark matter scattering on protons.

  7. Lake Powell

    NASA Technical Reports Server (NTRS)

    2007-01-01

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

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

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

  8. New data on seismic wave attenuation in the lithosphere and upper mantle of the northeastern flank of the Baikal rift system

    NASA Astrophysics Data System (ADS)

    Dobrynina, A. A.; Sankov, V. A.; Chechelnitsky, V. V.

    2016-05-01

    The investigation data on seismic wave attenuation in the lithosphere and upper mantle of the northeastern flank of the Baikal rift system obtained with a seismic coda envelope and sliding window are considered. Eleven local districts were described by one-dimensional attenuation models characterized by alternation of high and low attenuation layers, which are consistent with the results obtained previously by Yu.F. Kopnichev for the southwestern flank of the Baikal rift system [9]. The subcrust of the lithosphere contains a thin layer with high attenuation of seismic waves likely related to higher heterogeneity (fragmentation) and occurrence of fluids. The lithosphere basement depth varies from 100-120 km in the west within the Baikal folded area to 120-140 km in the east within the Siberian Platform. It is concluded that there are two asthenosphere layers. Based on specific features of the lithosphere and upper mantle structure, it can be assumed that they were subject to gradual modification involving fluidization processes and partial melting in the Late Cenozoic extension under the influence of distant tectogenesis sources.

  9. Implications of optical properties of ocean, lake, and ice for ultrahigh-energy neutrino detection

    SciTech Connect

    Price, P.B.

    1997-03-01

    The collecting power and imaging ability of planned ultrahigh-energy neutrino observatories depend on wavelength-dependent absorption and scattering coefficients for the detector medium. Published data are compiled for deep ice at the South Pole, for deep fresh water at Lake Baikal, and for deep seawater. The effective scattering coefficient is smallest for the clearest deep ocean sites, whereas the absorption coefficient is an order of magnitude smaller for deep ice than for the ocean and lake sites. The effective volume per detector element as a function of energy is calculated for electromagnetic cascades produced by electron neutrinos interacting at the various sites. It is largest for deep bubble-free ice, smallest for shallow bubbly ice, and intermediate for lake and seawater. The effective volume per element is calculated for detection of positrons resulting from the capture of a few megaelectron volt supernova neutrinos by protons in the medium. This volume is proportional to the absorption length and independent of the scattering length; it is larger for ice than for seawater or lake water. {copyright} 1997 Optical Society of America

  10. Redistribution of radionuclides between a microbial mat and a carbonate body at the Garga hot spring (Baikal Rift Zone)

    NASA Astrophysics Data System (ADS)

    Lazareva, E. V.; Zhmodik, S. M.; Melgunov, M. S.; Petrova, I. V.; Bryanskaya, A. V.

    2011-08-01

    The features of present deposits that form in the vicinity of hot springs can provide clues to the parameters of paleowaters in places of past hydrothermal activity marked by remnant carbonate and/or siliceous sinter. We investigated a large carbonate body at the Garga hot spring developing in the Baikal zone of nitric hydrotherms in the Barguzin Rift Zone valley. The main focus was on the structure of the carbonate mound, as well as on the partitioning of radioactive elements between the cyanobacterial mat and the inorganic component of the body (the issue that has never been explored before). The cyanobacterial community of the Garga spring is an active biosorbent of 226Ra, 228Ra, 210Pb. The radionuclides accumulated by biosorption become preserved in minerals that form within the bacterial community. The reported data of mineral formation in the cyanobacterial mat along with the mineralogy and structure of the carbonate mound of the Garga spring have implications for the complex history of the Garga body. It has been produced jointly by precipitation from the venting thermal water (opal-calcite-fluorite-barite-celestine assemblage) and microbial metabolic activity (coarse calcite and thin black encrustation rich in Mn minerals).

  11. Carbonate and silicate-carbonate injection complexes in collision systems: The West Baikal region as an example

    NASA Astrophysics Data System (ADS)

    Sklyarov, E. V.; Fedorovsky, V. S.; Kotov, A. B.; Lavrenchuk, A. V.; Mazukabzov, A. M.; Starikova, A. E.

    2013-05-01

    Two types of carbonate and carbonate-silicate rocks: synmetamorphic marble melange and veined bodies in amphibolites, gabbroic rocks, and syenites are recognized in the Early Paleozoic Ol'khon collision system in the West Baikal region. The marble melange is characterized by the various size of the fragments of the mafic granulite, gneisses, metagabbros, and granites. It is suggested that the melange was injected into the silicate matrix as a result of a ductile flow. The calcite, dolomite, and carbonate-silicate rocks are characterized by their massive and fine-grained texture. They are often associated with coeval granite and dolerite dikes and occasionally reveal indications of carbonate-silicate mingling. It is suggested that carbonate and carbonate-silicate rocks were injected at late stages of the synmetamorphic tectogenesis. In isotopic composition, geochemistry, and mineralogy, these carbonate rocks differ from mantle carbonatites, and their origin is most likely related to the melting of carbonate rocks in the lower crust in the presence of aqueous fluid according to the model proposed by Lentz [29]. The shearing facilitated drainage of the lower crust and the upper mantle and made it possible to inject carbonate material to the upper level as a melt and a ductile mixture along with crustal granitic and mantle-derived basic melts. The injection carbonate rocks have been described from other metamorphic complexes, e.g., in the Caledonides of Norway and in the Himalayan collision system.

  12. Mineralogical-geochemical features of travertines of the modern continental hydrotherms: A G-1 well, Tunka depression, Baikal rift zone

    NASA Astrophysics Data System (ADS)

    Soktoev, B. R.; Rikhvanov, L. P.; Ilenok, S. S.; Baranovskaya, N. V.; Taisaev, T. T.

    2015-07-01

    The mineral and chemical composition of travertines is studied in the modern discharge zone of the hydrothermal fluids of the Tunka depression, Baikal rift zone. The matrix of travertines is mostly made up of aragonite and calcite, which host about 20 mineral phases of Ag, Au, Pb, Cu, Sb, Sn, Fe, and other chemical elements. Similar rocks have previously been found in areas of modern submarine ore formation and tectonically active structures of the crust (New Zealand, the Cheleken Peninsula and others). Our materials confirm the opinion of some researchers who study modern hydrothermal ore formation in spreading zones that the formation of hydrothermal deposits requires favorable geochemical barriers rather than significant contents of metals in thermal waters. It is shown that microbial communities, concentrating chemical elements playing an important role in formation of ore mineralization in the discharge zones of thermal waters may be these barriers. According to our data, at the territory of the Tunka depression, thermal carbonic waters with endogenic components are delivered to the upper crustal horizons, involved in the existing hydrogeological systems, mixed with waters of active water exchange, and contribute to their chemical composition. This is manifested in the specific elemental and micromineral (Au, Ag, etc.) composition of the limescale of drinking water. In this local discharge zone, an effect of radioactive orphans has been found, which is similar to that established in barite chimneys from the Juan-de-Fuca Ridge.

  13. Molecular archives of climatic history: exploring patterns of genomic differentiation in endemic species radiations of ancient lakes (MOLARCH)

    NASA Astrophysics Data System (ADS)

    Martens, K.

    2009-04-01

    Little is known about the evolutionary response of species to global climate change because time scales are too long to be directly studied. Recent phylogenetic studies on taxa inhabiting ancient lakes suggested that climate-induced environmental changes can be reconstructed by analyzing genetic patterns within and among species. In fact such evolutionary responses seem to coincide with climate driven lake level-fluctuations and to be concentrated within narrow periods of time. Yet, it remains unclear to what extent such changes occur simultaneously across taxonomic groups and ecological guilds. Our study combines phylogenetic and paleoclimate data to test how patterns of evolutionary diversification agree with predictions of three groups of hypotheses (i) the ‘turnover pulse' and ‘paleo-ecological incumbency' hypotheses, predicting that speciation pulses across major taxa coincide with times of major lake level changes; (ii) the ‘ecological locking' hypothesis, also predicts simultaneous speciation pulses but not necessarily at times of major lake level changes; (iii) the ‘individual response' hypothesis, predicts no correlation of speciation pulses across taxa. These hypotheses will be tested using mtDNA sequences from selected endemic taxa (fish, crustaceans) of Lakes Baikal and Tanganyika, the two oldest lakes on Earth. Patterns of intraspecific diversity (reflecting dynamics of population size changes) and of the synchrony of interspecific divergences across taxa are used to investigate the evolutionary effects of lake level changes on different time scales, in taxa occurring in different habitats, within lakes and across continents. Combined with paleoclimatic information this will elucidate the effects of global climatic induced changes on the more general dynamics of diversification, loss of variation, adaptive radiations and speciation events. Computer simulations of sequence evolution generated in various ecological scenarios will be used to

  14. Anorogenic nature of magmatism in the Northern Baikal volcanic belt: Evidence from geochemical, geochronological (U-Pb), and isotopic (Pb, Nd) data

    USGS Publications Warehouse

    Neymark, L.A.; Larin, A.M.; Nemchin, A.A.; Ovchinnikova, G.V.; Rytsk, E. Yu

    1998-01-01

    The Northern Baikal volcanic belt has an age of 1.82-1.87 Ga and extends along the boundary between the Siberian Platform and the Baikal foldbelt. The volcanic belt is composed of volcanics of the Akitkan Group and granitic rocks of the Irel and Primorsk complexes. The geochemistry of the rocks points to the intraplate anorogenic nature of the belt. U-Pb zircon dating of the Chuya granitoids revealed that they are older (2020-2060 Ma) than the Northern Baikal volcanic belt and, thus, cannot be regarded as its component. Data on the Pb isotopic system of feldspars from the granitoids confirm the contemporaneity of all volcanic rocks of the belt except the volcanics of the upper portion of the Akitkan Group (Chaya Formation). Our data suggest its possibly younger (???1.3 Ga) age. The isotopic Nd and Pb compositions of the acid volcanic rocks provide evidence of the heterogeneity of their crustal protoliths. The volcanics of the Malaya Kosa Formation have ??Nd(T) = -6.1, ??2 = 9.36, and were most probably produced with the participation of the U-depleted lower continental crust of Archean age. Other rocks of the complex show ??Nd(T) from -0.1 to -2.4, ??2 = 9.78, and could have been formed by the recycling of the juvenile crust. The depletion of the Malaya Kosa volcanics in most LILEs and HFSEs compared with other acid igneous rocks of the belt possibly reflects compositional differences between the Late Archean and Early Proterozoic crustal sources. The basaltic rocks of the Malaya Kosa Formation (??Nd varies from -4.6 to -5.4) were produced by either the melting of the enriched lithospheric mantle or the contamination of derivatives of the depleted mantle by Early Archean lower crustal rocks, which are not exposed within the area. Copyright ?? 1998 by MAEe Cyrillic signK Hay??a/Interperiodica Publishing.

  15. The large Bystrinskoe Cu-Au-Fe deposit (Eastern Trans-Baikal Region): Russia's first example of a skarn-porphyry ore-forming system related to adakite

    NASA Astrophysics Data System (ADS)

    Kovalenker, V. A.; Abramov, S. S.; Kiseleva, G. D.; Krylova, T. L.; Yazykova, Yu. I.; Bortnikov, N. S.

    2016-06-01

    The Bystrinskoe skarn-porphyry Cu-Au-Fe deposit (Eastern Trans-Baikal Region) is confined to skarn zones, which were formed along the contact of granitoids referred to the Shakhtama intrusive complex (J2-3), with terrigenous-carbonate sedimentary rocks. Commercial (Cu-Au-Fe ± W, Mo) mineralization was formed due to the regional postcollision development involving the intrusion of porphyritic granitoids, the derivatives of oxidized adakite highly magnesian magmas enriched in water, sulfur, and metals, which could develop under melting of garnet-bearing amphibolite in the mafic lower crustal arc.

  16. Longevity of Lake Superior lake trout

    USGS Publications Warehouse

    Schram, Stephen T.; Fabrizio, Mary C.

    1998-01-01

    The age structure of mature lake trout Salvelinus namaycush from the Wisconsin waters of Lake Superior increased following a population recovery that has taken place since the 1960s. As the population aged, it became apparent that scales were unreliable aging structures. Beginning in 1986, we examined both scale and sagittal otolith ages from tagged fish with a known period at liberty. We found large discrepancies in scale and sagittal otolith ages of mature fish, such that scale ages were biased low. We estimated lake trout living up to 42 years, which is greater than previously reported from Lake Superior. Investigators studying lake trout population dynamics in the Great Lakes should be aware that lake trout can live longer than previously thought.

  17. Lake Volta, Ghana

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image of Lake Volta in Ghana was acquired March 31, 2002 by the Moderate Resolution Imaging Spectroradiometer (MODIS). Lake Volta is one of the world's largest artificially created lakes. Lake Volta is actually a reservoir formed from the damming of the Volta River, and extends 250 miles north of the Akosombo Dam. The lake covers an area of 8,482 square km. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  18. Specific features of electric field in the atmosphere and Radon emanations in Tunkin Basin of Baikal rift zone

    NASA Astrophysics Data System (ADS)

    Soloviev, S.; Loktev, D.

    2013-05-01

    Development of methods for diagnosing local crust encourages finding new ways for preventing hazardous geologic phenomena. Using measurements of several geophysical fields in addition to seismic methods enables to improve the existing methods and increase their reliability. In summer of 2009 and 2010, complex geophysical acquisition company was organized in the Tunkin Basin of the Baikal rift zone in South-Eastern Siberia, that runs 200 km to East-West from the southern tip of Baikal. Stationary observations were carried out in the central part of the Tunkin Basin, at the Geophysical observatory "I" of Institute of Solar-Terrestrial Physics of Siberian Branch of RAS and "II" near the Arshan settlement. Along with observations of microseismic noise and electric field variations in soil, there were performed measurements of electric field strength (Ez) in lowest atmosphere and volumetric activity of natural Radon in subsoil. Meteorological parameters were monitored with the use of DavisVantagePro meteorological stations. The analysis of observations showed that characteristic features of electric field in near-surface atmosphere are majorly defined by complex orography of the place and, consequently, by quickly changing meteorological conditions: thunderstorm activity and other mesometeorological events (with characteristic scale of tens of km and few hours long) in nearby rocks. The results of Ez(t) measurements performed under "good" weather conditions showed that the character of field variations depended on the local time with their maximum in daylight hours and minimum in the night. The analysis of Radon volumetric activity evidenced that its variations are influenced by atmospheric pressure and tides, and such influence is different at points "I" and "II". In particular, the tidal and atmospheric influence on Radon variations is more pronounced at "II" if compared to "I", which can be explained by locations of the registration points. Registration Point "II" is

  19. The mineralogy and geochemistry of quartz-tourmaline schlieren in the granites of the Primorsky Complex, Western Baikal Region

    NASA Astrophysics Data System (ADS)

    Savel'eva, V. B.; Bazarova, E. P.; Kanakin, S. V.

    2014-12-01

    Quartz-tourmaline schlieren have been found within rapakivi-like granites of the Early Proterozoic Primorsky Complex in the Western Baikal Region. These rocks are biotite leucogranites with normal alkalinity (A/CNK = 1.00-1.04); a high iron mole fraction (92-95%); a K2O/Na2O value of about 2.0; relatively high F, Li, Rb, Cs, Sn, Pb, Th, and U contents; and low Ba, Sr, Eu, Zn, Sc, and V contents. The schlieren composed of quartz and tourmaline with relics of feldspar also contain fluorite, rare muscovite, chlorite, and accessory rutile, ilmenite, zircon, monazite, xenotime, and bastnäsite. B2O3 and F contents in the schlieren are 2.29-2.63 and 0.30-0.47 wt %, respectively. Fe2O3 (4.8-5.4 wt %), F, and H2O contents are higher in these schlieren than in the host granite, while SiO2, CaO, Na2O, K2O, and P2O5 contents are lower than in host rocks. K2O/Na2O values decrease in the schlieren down to 0.4. Enrichment of the schlieren in Fe and other ore elements (Zn, Co, Cu, Sn, etc.), together with B, F, H2O, and Na, suggests that they crystallized from fluid-saturated melt segregated from aluminosilicate melt in the apical part of a shallow-seated intrusion. The formation of tourmaline may be related to the interaction of the fluid with feldspars in the crystallizing granites; it was accompanied by a separation of fluid F-CO2. Quartz precipitated at the next stage, due to the acidic character of the aqueous fluid. In general, the relationships of minerals in the schlieren indicate distinct fractionation of LREE, HREE, and Y in the fluid-saturated melt.

  20. A simplified physically-based model to calculate surface water temperature of lakes from air temperature in climate change scenarios

    NASA Astrophysics Data System (ADS)

    Piccolroaz, S.; Toffolon, M.

    2012-12-01

    conditions. As a general result, the model allows one to obtain long-term series of estimated water temperatures, which can be valuably considered in climate change studies. The model has been applied to different lakes (Lake Baikal, Siberia; Lake Garda, Italy; Great Lakes, Canada and USA; Lake Mara, Canada) showing a noticeable agreement with the validation datasets and allowing for predictions of future trends of lake surface water temperature. Finally, it is worth noting that if the model is calibrated using air temperature series from climate models (global scale) and measured records of water temperature (lake scale), air temperatures are contemporaneously converted and downscaled. In conclusion, the model can be used as a downscaling tool, both for historical conditions and projected scenarios.

  1. Lake Nasser and Toshka Lakes, Egypt

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Lake Nasser (center) and the Toshka Lakes (center left) glow emerald green and black in this MODIS true-color image acquired March 8, 2002. Located on and near the border of Egypt and Norther Sudan, these lakes are an oasis of water in between the Nubian (lower right) and Libyan Deserts (upper left). Also visible are the Red Sea (in the upper right) and the Nile River (running north from Lake Nasser). Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  2. Lakes Ecosystem Services Online

    EPA Science Inventory

    Northeastern lakes provide valuable ecosystem services that benefit residents and visitors and are increasingly important for provisioning of recreational opportunities and amenities. Concurrently, however, population growth threatens lakes by, for instance, increasing nutrient ...

  3. Utah: Salt Lake Region

    Atmospheric Science Data Center

    2014-05-15

    article title:  Winter and Summer Views of the Salt Lake Region     View Larger Image Magnificent views of the region surrounding Salt Lake City, Utah are captured in these winter and summer images from the ...

  4. Lake trout rehabilitation in Lake Ontario

    USGS Publications Warehouse

    Elrod, Joseph H.; O'Gorman, Robert; Schneider, Clifford P.; Eckert, Thomas H.; Schaner, Ted; Bowlby, James N.; Schleen, Larry P.

    1995-01-01

    Attempts to maintain the native lake trout (Salvelinus namaycush) population in Lake Ontario by stocking fry failed and the species was extirpated by the 1950s. Hatchery fish stocked in the 1960s did not live to maturity because of sea lamprey (Petromyzon marinus) predation and incidental commercial harvest. Suppression of sea lampreys began with larvicide treatments of Lake Ontario tributaries in 1971 and was enhanced when the tributaries of Oneida Lake and Lake Erie were treated in the 1980s. Annual stocking of hatchery fish was resumed with the 1972 year class and peaked at about 1.8 million yearlings and 0.3 million fingerlings from the 1985–1990 year classes. Survival of stocked yearlings declined over 50% in the 1980 s and was negatively correlated with the abundance of lake trout > 550 mm long (r = −0.91, P < 0.01, n = 12). A slot length limit imposed by the State of New York for the 1988 fishing season reduced angler harvest. Angler harvest in Canadian waters was 3 times higher in eastern Lake Ontario than in western Lake Ontario. For the 1977–1984 year classes, mean annual survival rate of lake trout age 6 and older was 0.45 (range: 0.35–0.56). In U.S. waters during 1985–1992, the total number of lake trout harvested by anglers was about 2.4 times greater than that killed by sea lampreys. The number of unmarked lake trout < 250 mm long in trawl catches in 1978–1992 was not different from that expected due to loss of marks and failure to apply marks at the hatchery, and suggested that recruitment of naturally-produced fish was nil. However, many of the obstacles which may have impeded lake trout rehabilitation in Lake Ontario during the 1980s are slowly being removed, and there are signs of a general ecosystem recovery. Significant recruitment of naturally produced lake trout by the year 2000, one interim objective of the rehabilitation plan for the Lake, may be achieved.

  5. Comparison of ALOS PALSAR interferometry and field geodetic leveling for marshy soil thaw/freeze monitoring, case study from the Baikal lake region, Russia

    NASA Astrophysics Data System (ADS)

    Chimitdorzhiev, Tumen N.; Dagurov, Pavel N.; Bykov, Michael E.; Dmitriev, Aleksey V.; Kirbizhekova, Irina I.

    2016-01-01

    Estimation of vertical ground displacements due to seasonal periods of freezing and thawing was carried out on the Selenga river mouth using differential radar interferometry. The results of seasonal radar interferometry measurements from 2008 to 2010 have been compared with the survey data for 2011, under the assumption that the seasonal deformation is comparable for different years and lies within the limits of geodetic leveling error. The difference between the interferometric and geodetic measurements is <1 cm in winter months, whereas in summer, as the upper soil moisture content varies, the difference reaches 2 to 2.7 cm. It has been concluded that the moisture content and its profile should be taken into consideration in summer or when choosing the radar interferometry in winter.

  6. SARAL/AltiKa observations for the studies of ice cover on lakes and oceans

    NASA Astrophysics Data System (ADS)

    Kouraev, Alexei; Zakharova, Elena; Remy, Frederique; Fleury, Sara; Guerreiro, Kevin; Willmes, Sascha; Suknev, Andrei

    2015-04-01

    With the launch of SARAL/AltiKa satellite mission scientific community has now a new source of information to study ice cover on water bodies and oceans. AltiKa observations provide a continuity with the previous satellite radar altimetry observations from ERS-1, -2 and ENVISAT mission that have the same orbit. Moreover, with the new Ka-band altimeter it gives new insights into the ice cover structure and properties. We present studies of ice cover on lakes (Lake Baikal) and Arctic ocean (for leads and polynyas detection). For Lake Baikal we use the synergy of simultaneous active (radar altimeter) and passive (radiometer) observations from radar altimetric satellites - SARAL/Altika and also TOPEX/Poseidon, Jason-1, ENVISAT and Geosat Follow-On. We present ice discrimination methodology from different satellite missions and discuss specificity of AltiKa observations. We analyse temporal variability of altimetric waveform parameters over ice-covered and ice-free surface for AltiKa and complement this analysis by satellite imagery (MODIS, Landsat), as well as our dedicated field observations of ice cover properties along the AltiKa tracks in spring 2013 and 2014. For the Arctic ocean we investigate the performance of SARAL/AltiKa to detect the leads and the coastal polynyas as well as its ability to represent spatial and temporal dynamic of water openings. The method consists first in analysis of along-track radar waveforms with collocated high-resolution Landsat images in order to localise ice/water transitions. We discuss the potential of several techniques that could be used for leads and polynya studies and for freeboard estimation. This research has been done in the framework of the Russian-French cooperation GDRI "CAR-WET-SIB", CNES TOSCA AO, ANR "CLASSIQUE", IDEX Transversalité InHERA, CNRS-Russia "Franco-Siberian Center for Research and Education" and PICS BaLaLaICA, ESA Proposal C1P.13132, Russian FZP 1.5 and EU FP7 "MONARCH-A" projects.

  7. Lake Layers: Stratification.

    ERIC Educational Resources Information Center

    Brothers, Chris; And Others

    This teacher guide and student workbook set contains two learning activities, designed for fifth through ninth grade students, that concentrate on lake stratification and water quality. In the activities students model the seasonal temperature changes that occur in temperate lakes and observe the resulting stratification of lake waters. Students…

  8. Great Lakes: Chemical Monitoring

    ERIC Educational Resources Information Center

    Delfino, Joseph J.

    1976-01-01

    The Tenth Great Lakes Regional Meeting of the American Chemical Society met to assess current Chemical Research activity in the Great Lakes Basin, and addressed to the various aspects of the theme, Chemistry of the Great Lakes. Research areas reviewed included watershed studies, atmospheric and aquatic studies, and sediment studies. (BT)

  9. Great Minds? Great Lakes!

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Chicago, IL. Great Lakes National Program Office.

    This book contains lesson plans that provide an integrated approach to incorporating Great Lakes environmental issues into elementary subjects. The book is divided into three subject areas: (1) History, which includes the origins of the Great Lakes, Great Lakes people, and shipwrecks; (2) Social Studies, which covers government, acid rain as a…

  10. 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.…

  11. Lake Effects: The Lake Superior Curriculum Guide.

    ERIC Educational Resources Information Center

    Beery, Tom; And Others

    This curriculum guide was launched in response to a need for Lake Superior-specific educational materials and contains lessons and activities that can be used to teach about Lake Superior. The lessons in this book are divided into four sections. Each of the first three sections has a background section that provides basic information about Lake…

  12. Food of lake trout in Lake Superior

    USGS Publications Warehouse

    Dryer, William R.; Erkkila, Leo F.; Tetzloff, Clifford L.

    1965-01-01

    Stomachs were examined from 1,492 lake trout and 83 siscowets collected from Lake Superior. Data are given on the food of lake trout of legal size (17 inches or longer) by year, season, and depth of water, and on the relation between food and size among smaller lake trout. Fish contributed 96.7 to 99.9 per cent of the total volume of food in the annual samples. Ciscoes (Coregonus spp.) were most common (52.2 to 87.5 per cent of the volume) in 1950 to 1953 and American smelt ranked first (65.6 per cent of the volume) in 1963. Cottids were in 8.9 to 12.3 per cent of the stomachs in 1950 to 1953 but in only 4.3 per cent in 1963. Insects ranked second to fish in occurrence (9.6 per cent for the combined samples) and crustaceans followed at 3.9 per cent. The greatest seasonal changes in the food of lake trout were among fish caught at 35 fathoms and shallower. The occurrence of Coregonus increased from 34.6 per cent in February-March to 71.1 per cent in October-December. Smelt were in 76.9 per cent of the stomachs in February-March but in only 2.2 per cent in October-December. Cottids, Mysis relicta, and insects were most common in the July-September collections. Lake trout taken at depths greater than 35 fathoms had eaten a higher percentage of Cottidae and Coregonus than had those captured in shallower water. Smelt, ninespine sticklebacks, Mysis, and insects were more frequent in stomachs of lake trout from less than 35 fathoms. Crustaceans comprised more than 70 per cent of the total volume of food for 4.0- to 7.9-inch lake trout but their importance decreased as the lake trout grew larger. Pontoporeia affinis was the most common in the stomachs of 4.0- to 6.9-inch lake trout and Mysis held first rank at 7.0 to 12.9 inches. Ostracods were important only to 4.0- to 4.9-inch lake trout. As the lake trout became larger, the importance of fish grew from 4.4-per cent occurrence at 5.0 to 5.9 inches to 93.9 per cent at 16.0 to 16.9 inches. Smelt were most commonly eaten by

  13. Diatoms from Lake Kushu: A pilot study to test the potential of a Late Quaternary palaeoenvironmental archive from Rebun Island (Hokkaido Region, Japan)

    NASA Astrophysics Data System (ADS)

    Schmidt, Mareike; Tarasov, Pavel E.; Hoelzmann, Philipp; Meyer, Hanno; Leipe, Christian

    2016-05-01

    Rebun Island is a key research area for the Baikal-Hokkaido Archaeology Project to better understand the dynamics of the Neolithic hunter-gatherers in the NW Pacific region. Hence, the ca. 19.5 m sediment core RK12 spanning the last ca. 16.6 cal. kyr BP was obtained from Lake Kushu. Our aim is to test its potential as a high-resolution multi-proxy archive. Here, we used diatoms to investigate the modern ecosystem of Lake Kushu and its surrounding area on Rebun Island and of Hime-numa Pond on Rishiri Island and selected core samples for comparison. Modern diatom and stable isotope analyses show well-mixed freshwater bodies with eutrophic, alkaline conditions. The fossil diatom and geochemical sediment analyses display three phases that represent major changes in the lake development: (i) a marshy phase (ca. 16.6-10 cal. kyr BP); (ii) a brackish water lagoon phase (ca. 10-6.6 cal. kyr BP); and (iii) a freshwater lake phase (since ca. 6.6 cal. kyr BP). This shows the major role of the post-glacial climate amelioration, global sea-level rise and marine transgression in the development of this landscape. Further analyses will provide a palaeolimnological record at (sub-)decadal resolution that will facilitate the interpretation of the hunter-gatherer dynamics.

  14. Water quality of Lake Austin and Town Lake, Austin, Texas

    SciTech Connect

    Andrews, F.L.; Wells, F.C.; Shelby, W.J.; McPherson, E.M.

    1988-01-01

    Lake Austin and Town Lake are impoundments on the Colorado River in Travis County, central Texas, and are a source of water for municipal industrial water supplies, electrical-power generation, and recreation for more than 500,000 people in the Austin metropolitan area. Small vertical temperature variations in both lakes were attributed to shallow depths in the lakes and short retention times of water in the lakes during the summer months. The largest areal variations in dissolved oxygen generally occur in Lake Austin during the summer as a result of releases of water from below the thermocline in Lake Travis. Except for iron, manganese, and mercury, dissolved concentrations of trace elements in water collected from Lake Austin and Town Lake did not exceed the primary or secondary drinking water standards set by the US Environmental Protection Agency. Little or no effect of stormwater runoff on temperature, dissolved oxygen, or minor elements could be detected in either Lake Austin or Town Lake. Little seasonal or areal variation was noted in nitrogen concentrations in Lake Austin or Town lake. Total phosphorus concentrations generally were small in both lakes. Increased concentrations of nitrogen and phosphorus were detected after storm runoff inflow in Town Lake, but not in Lake Austin; densities of fecal-coliform bacteria increased in Lake Austin and Town Lake, but were substantially greater in Town Lake than in Lake Austin. 18 refs., 38 figs., 59 tabs.

  15. Lake trout rehabilitation in Lake Huron

    USGS Publications Warehouse

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

    1995-01-01

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

  16. Changes of clay mineral assemblages in Lake Hovsgol (Mongolia) in the course of their transportation and sedimentation

    NASA Astrophysics Data System (ADS)

    Zhdanova, A.; Solotchina, E.; Krivonogov, S.

    2009-04-01

    As known, clay minerals of lake sediments sensitively indicate climatic and environmental changes. Composition of clay mineral assemblages depends on petrography and weathering pattern of parental rocks in lake catchments. Lake Hovsgol, the second large basin in the Baikal Rift Zone, differs from the first one by extremely small drainage area: its ratio to the lake surface is 1.8 (compare with 17 of Lake Baikal). This peculiarity of lake Hovsgol defines the amount of clay minerals deposited in bottom sediments and the value of their transformation in the course of transportation We studied a number of short sediment cores (up to 1.75 m long) obtained from different parts of the lake in the framework of the Hovsgol Drilling Project, 2001-2007. Regularities of modern clay minerals transportation were studied in 80 samples from river mouths and piedmont slopes around the lake. Their mineral composition was determined by X-ray powder diffraction and IR-spectroscopy. For X-ray, we prepared the oriented mounts by transferring the suspension of bulk sample in distilled water onto a glass slide. Slides, dried at room temperature, then were solvated for about 24 hours with ethylene-glycol vapor in an evacuated desiccator. Measurements were conducted on an automated powder diffractometer with CuKα radiation, graphite monochromator. The comparative analysis of clay minerals and their crystallochemical parameters were performed by the original method of modeling X-ray diffraction profiles, based on the calculation of the interference function of the one-dimensional disordered crystals with finite thickness and using a specially developed optimization procedure. Quantitative estimations of the composition of minerals such as quartz, plagioclase, carbonate were made by IR-spectroscopy. Samples were prepared using the KBr pellet method. It was established that the mineral association in bottom sediments includes illite, smectite, chlorite, chlorite-smectite, muscovite, kaolinite

  17. Height of faceted spurs, a proxy for determining long-term throw rates on normal faults: Evidence from the North Baikal Rift System, Siberia

    NASA Astrophysics Data System (ADS)

    Petit, Carole; Meyer, Bertrand; Gunnell, Yanni; Jolivet, Marc; San'kov, Vladimir; Strak, Vincent; Gonga-Saholiariliva, Nahossio

    2010-05-01

    We present new results on the long-term throw rates of active normal faults in the North Baikal Rift (NBR), eastern Siberia, based on a statistical analysis of triangular faceted scarps. Faceted spurs or triangular facets are morphologic features frequently observed along normal fault scarps, and result from the progressive denudation and incision of the footwall during fault activity. Fault-bounded ridges in the NBR display such typical morphologies with several contiguous facets separated by fault-perpendicular catchments. Over a range of 20 fault segments analyzed, triangular facet heights vary from ~200 to >900 m. As fault scarps have been developing under similar long-term climatic conditions, we infer that the scatter in mean facet height arises from long-term differences in fault throw rate. We compare the morphology of NBR facets with results obtained in a previously published numerical model of facet growth, which predicts that the mean height of triangular facets is proportional to the fault throw rate. Using facet height as an input, model results provide estimates of the long-term fault throw rates in the NBR. These vary between 0.2 and 1.2 mm/yr. The throw rates are then compared with the cumulated throw, which has been constrained by geophysical and stratigraphic data in the basins. This provides an estimate of the age of fault and basin initiation. We show that the modern stage of basin development started circa 3 Myr ago, except for the North Baikal basin (~ 8 Ma). Our results also suggest that a proportion of the observed throw is inherited from an earlier tectonic stage.

  18. View of Lake Sabrina Dam and Lake Sabrina from east ...

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

    View of Lake Sabrina Dam and Lake Sabrina from east ridge showing spillway at photo center, view southwest - Bishop Creek Hydroelectric System, Plant 2, Lake Sabrina Dam, Bishop Creek, Bishop, Inyo County, CA

  19. Genesis of rare-metal pegmatites and alkaline apatite-fluorite rocks of Burpala massi, Northern Baikal folded zone

    NASA Astrophysics Data System (ADS)

    Sotnikova, Irina; Vladykin, Nikolai

    2015-04-01

    Burpalinsky rare metal alkaline massif in the Northern Baikal folded zone in southern margin of Siberian Platform, is a of intrusion central type, created 287 Ma covering area of about 250 km2. It is composed of nepheline syenites and pulaskites grading to quartz syenites in the contacts. Veines and dykes are represented by shonkinites, sodalite syenite, leucocratic granophyres, alkali granites and numerous rare metal alkaline syenite pegmatites and two dykes of carbonatites. All rocks except for granites are cut by a large apatite-fluorite dyke rocks with mica and magnetite, which in turn is cut by alaskite granites dyke. The massif has been studied by A.M. Portnov, A.A. Ganzeev et al. (1992) Burpalinsky massif is highly enriched with trace elements, which are concentrated in pegmatite dykes. About 70 rare-metal minerals we found in massif. Zr-silicates: zircon, eudialyte, lovenite, Ti-lovenite, velerite, burpalite, seidozerite, Ca- seidozerite, Rosenbuschite, vlasovite, katapleite, Ca-katapleite, elpidite. Ti- minerals:- sphene, astrophyllite, ramsaite, Mn-neptunite bafertisite, chevkinite, Mn-ilmenite, pirofanite, Sr-perrerit, landauite, rutile, anatase, brookite; TR- minerals - loparite, metaloparite, britolite, rinkolite, melanocerite, bastnesite, parisite, ankilite, monazite, fluocerite, TR-apatite; Nb- minerals - pyrochlore, loparite. Other rare minerals leucophanite, hambergite, pyrochlore, betafite, torite, thorianite, tayniolite, brewsterite, cryolite and others. We have proposed a new scheme massif: shonkinites - nepheline syenites - alkaline syenite - quartz syenites - veined rocks: mariupolites, rare-metal pegmatites, apatite, fluorite rock alyaskite and alkaline granites and carbonatites (Sotnikova, 2009). Apatite-fluorite rocks are found in the central part of massif. This is a large vein body of 2 km length and a 20 m width cutting prevailing pulaskites. Previously, these rocks were regarded as hydrothermal low-temperature phase. New geological and

  20. Origins of rainbow smelt in Lake Ontario

    USGS Publications Warehouse

    Bergstedt, Roger A.

    1983-01-01

    The first rainbow smelt (Osmerus mordax) to enter Lake Ontario were probably migrants from an anadromous strain introduced into New York's Finger Lakes. Since the upper Great Lakes were originally stocked with a landlocked strain from Green Lake, Maine, subsequent migration to Lake Ontario from Lake Erie makes Lake Ontario unique among the Great Lakes in probably having received introductions from two distinct populations.

  1. David Morrison on Lake Vostok

    NASA Video Gallery

    Dr. David Morrison discusses the implications of research possibilities at Lake Vostok, one of the largest subglacial lakes located over two miles beneath the ice in Antarctica. The lake has been c...

  2. Lake Mead, NV

    NASA Technical Reports Server (NTRS)

    1982-01-01

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

  3. Great Lakes Literacy Principles

    NASA Astrophysics Data System (ADS)

    Fortner, Rosanne W.; Manzo, Lyndsey

    2011-03-01

    Lakes Superior, Huron, Michigan, Ontario, and Erie together form North America's Great Lakes, a region that contains 20% of the world's fresh surface water and is home to roughly one quarter of the U.S. population (Figure 1). Supporting a $4 billion sport fishing industry, plus $16 billion annually in boating, 1.5 million U.S. jobs, and $62 billion in annual wages directly, the Great Lakes form the backbone of a regional economy that is vital to the United States as a whole (see http://www.miseagrant.umich.edu/downloads/economy/11-708-Great-Lakes-Jobs.pdf). Yet the grandeur and importance of this freshwater resource are little understood, not only by people in the rest of the country but also by many in the region itself. To help address this lack of knowledge, the Centers for Ocean Sciences Education Excellence (COSEE) Great Lakes, supported by the U.S. National Science Foundation and the National Oceanic and Atmospheric Administration, developed literacy principles for the Great Lakes to serve as a guide for education of students and the public. These “Great Lakes Literacy Principles” represent an understanding of the Great Lakes' influences on society and society's influences on the Great Lakes.

  4. Lakes, Lagerstaetten, and Evolution

    NASA Astrophysics Data System (ADS)

    Kordesch, E. G.; Park, L. E.

    2001-12-01

    The diversity of terrestrial systems is estimated to be greater than in the marine realm. However no hard data yet exists to substantiate this claim. Ancient lacustrine deposits may preserve an exceptionally diverse fossil fauna and aid in determining continental faunal diversities. Fossils preserved in lake deposits, especially those with exceptional preservation (i.e. Konservat Lagerstaetten), may represent a dependable method for determining species diversity changes in the terrestrial environment because of their faunal completeness. Important Konservat Lagerstaetten, such as the Green River Formation (US) and Messel (Germany), both Eocene in age, are found in lake sediments and show a remarkable faunal diversity for both vertebrates and invertebrates. To date information from nearly 25 lake lagerstaetten derived from different types of lake basins from the Carboniferous to the Miocene have been collected and described. Carboniferous sites derive from the cyclothems of Midcontinent of the US while many Cenozoic sites have been described from North and South America as well as Europe and Australia. Asian sites contain fossils from the Mesozoic and Cenozoic. With this data, insight into the evolutionary processes associated with lake systems can be examined. Do lakes act as unique evolutionary crucibles in contrast to marine systems? The speciation of cichlid fishes in present-day African lakes appears to be very high and is attributed to the diversity of environments found in large rift lakes. Is this true of all ancient lakes or just large rift lakes? The longevity of a lake system may be an important factor in allowing speciation and evolutionary processes to occur; marine systems are limited only in the existence of environments as controlled by tectonics and sea level changes, on the order of tens of millions of years. Rift lakes are normally the longest lived in the millions of years. Perhaps there are only certain types of lakes in which speciation of

  5. Lessons from a Lake.

    ERIC Educational Resources Information Center

    Goethals, Susan

    1997-01-01

    Describes a study that included classroom lessons on hydroelectric power, the history and construction of a nearby lake, data recording, the use of field guides, and methods of counting natural populations. The study culminated in a field trip to the lake. (JRH)

  6. Great Lakes: Great Gardening.

    ERIC Educational Resources Information Center

    New York Sea Grant Inst., Albany, NY.

    This folder contains 12 fact sheets designed to improve the quality of gardens near the Great Lakes. The titles are: (1) "Your Garden and the Great Lakes"; (2) "Organic Gardening"; (3) "Fruit and Vegetable Gardening"; (4) "Composting Yard Wastes"; (5) "Herbicides and Water Quality"; (6) "Watering"; (7) "Soil Erosion by Water"; (8) "Soil…

  7. Venezuela: Lake Maracaibo

    Atmospheric Science Data Center

    2013-04-18

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

  8. Lake Effect Clouds

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The lake effect is particularly clear in this Sea-viewing Wide field-of-view Sensor (SeaWiFS) true-color image of the North American Great Lakes region, acquired December 5, 2000. Lakes Nipigon, Superior, and Michigan show striking contrasts between clear and cloudy air as the wind blows from the northwest across the lakes. As it flows across the relatively warm lakes, the cold dry air gathers heat and moisture from the surface. The warm moist air rises into the atmosphere and mixes vigorously with the cold dry air above. The layer of warm moist air deepens as it travels across the lake. Some of the evaporated water from the lake condenses into streamers of fog rising from the surface, while much of the moisture condenses to form a stratocumulus cloud in the upper half of the mixed layer. The cloud-forming water droplets may freeze into ice crystals and, due to accumulated water deposition over time, grow into snowflakes. This process can generate snowstorms that produce significant amounts of snowfall downwind. It is not uncommon for lake effect snowstorms to produce as much as two feet of snow within a 24-hour period in northwestern parts of New York and Pennsylvania. Image provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  9. GREAT LAKES LIMNOLOGY MONITORING

    EPA Science Inventory

    The Great Lakes National Program Office (GLNPO) of the United States Environmental Protection Agency (USEPA) has primary responsibility within the U.S. for conducting surveillance monitoring of the offshore waters of the Great Lakes. This monitoring is intended to fulfill provis...

  10. The Great Lakes.

    ERIC Educational Resources Information Center

    Seasons, 1987

    1987-01-01

    The Great Lakes are one of the world's greatest reserviors of fresh water, the foundation of Ontario's economic development, a primary force in ecological systems, and a base for pleasure and recreation. These lakes and their relationship with people of Canada and the United States can be useful as a subject for teaching the impact of human…

  11. The lakes of Titan

    USGS Publications Warehouse

    Stofan, E.R.; Elachi, C.; Lunine, J.I.; Lorenz, R.D.; Stiles, B.; Mitchell, K.L.; Ostro, S.; Soderblom, L.; Wood, C.; Zebker, H.; Wall, S.; Janssen, M.; Kirk, R.; Lopes, R.; Paganelli, F.; Radebaugh, J.; Wye, L.; Anderson, Y.; Allison, M.; Boehmer, R.; Callahan, P.; Encrenaz, P.; Flamini, E.; Francescetti, G.; Gim, Y.; Hamilton, G.; Hensley, S.; Johnson, W.T.K.; Kelleher, K.; Muhleman, D.; Paillou, P.; Picardi, G.; Posa, F.; Roth, L.; Seu, R.; Shaffer, S.; Vetrella, S.; West, R.

    2007-01-01

    The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface. Initial visible and radar imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface. Here we provide definitive evidence for the presence of lakes on the surface of Titan, obtained during the Cassini Radar flyby of Titan on 22 July 2006 (T16). The radar imaging polewards of 70?? north shows more than 75 circular to irregular radar-dark patches, in a region where liquid methane and ethane are expected to be abundant and stable on the surface. The radar-dark patches are interpreted as lakes on the basis of their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. Some of the lakes do not completely fill the depressions in which they lie, and apparently dry depressions are present. We interpret this to indicate that lakes are present in a number of states, including partly dry and liquid-filled. These northern-hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface 'liquid methane' table. ??2007 Nature Publishing Group.

  12. Great Lakes Teacher's Guide.

    ERIC Educational Resources Information Center

    Reid, Ron

    The Great Lakes are one of the world's greatest reservoirs of fresh water, the foundation of Ontario's economic development, a primary force in ecological systems, and a base for pleasure and recreation. They are also a magnificent resource for the teachers of Ontario. Study of the Great Lakes can bring to life the factors that shape the ecology…

  13. Lake trophic applications: Wisconsin

    NASA Technical Reports Server (NTRS)

    Scarpace, F.

    1981-01-01

    Efforts to classify the water quality characteristics of lakes using LANDSAT imagery are reported. Image processing and registration techniques are described. A lake classification scheme which involves the assignment of a trophic class number was used in the data analysis. The resulting values were compared to the corresponding rank assignment derived from field measurements.

  14. Lake Wobegon Dice

    ERIC Educational Resources Information Center

    Moraleda, Jorge; Stork, David G.

    2012-01-01

    We introduce Lake Wobegon dice, where each die is "better than the set average." Specifically, these dice have the paradoxical property that on every roll, each die is more likely to roll greater than the set average on the roll, than less than this set average. We also show how to construct minimal optimal Lake Wobegon sets for all "n" [greater…

  15. Lakes and reservoirs

    SciTech Connect

    Taub, F.B.

    1984-01-01

    This volume in the Ecosystems of the World series studies lakes and reservoirs. The book opens with a discussion of the ecosystem processes that are common to all lakes and reservoirs and then proceeds to a description of mathematical models of these processes. The chapters concentrate on lakes and reservoirs in different parts of the world, ranging from polar to tropical lakes, and in many of the chapters the effects of human activities such as dam construction, increased nutrient inputs, toxic contaminants and fish introduction, are also considered. The book concludes with a summary of the efforts at lake restoration that are being undertaken in many communities in an attempt to undo the damage that has resulted from some of these activities.

  16. Lake trout in northern Lake Huron spawn on submerged drumlins

    USGS Publications Warehouse

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

    2014-01-01

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

  17. Spatial patterns in PCB concentrations of Lake Michigan lake trout

    USGS Publications Warehouse

    Madenjian, Charles P.; DeSorcie, Timothy J.; Stedman, Ralph M.; Brown, Edward H., Jr.; Eck, Gary W.; Schmidt, Larry J.; Hesselberg, Robert J.; Chernyak, Sergei M.; Passino-Reader, Dora R.

    1999-01-01

    Most of the PCB body burden in lake trout (Salvelinus namaycush) of the Great Lakes is from their food. PCB concentrations were determined in lake trout from three different locations in Lake Michigan during 1994–1995, and lake trout diets were analyzed at all three locations. The PCB concentrations were also determined in alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), bloater (Coregonus hoyi), slimy sculpin (Cottus cognatus), and deepwater sculpin (Myoxocephalus thompsoni), five species of prey fish eaten by lake trout in Lake Michigan, at three nearshore sites in the lake. Despite the lack of significant differences in the PCB concentrations of alewife, rainbow smelt, bloater, slimy sculpin, and deepwater sculpin from the southeastern nearshore site near Saugatuck (Michigan) compared with the corresponding PCB concentrations from the northwestern nearshore site near Sturgeon Bay (Wisconsin), PCB concentrations in lake trout at Saugatuck were significantly higher than those at Sturgeon Bay. The difference in the lake trout PCB concentrations between Saugatuck and Sturgeon Bay could be explained by diet differences. The diet of lake trout at Saugatuck was more concentrated in PCBs than the diet of Sturgeon Bay lake trout, and therefore lake trout at Saugatuck were more contaminated in PCBs than Sturgeon Bay lake trout. These findings were useful in interpreting the long-term monitoring series for contaminants in lake trout at both Saugatuck and the Wisconsin side of the lake.

  18. Evidence of offshore lake trout reproduction in Lake Huron

    USGS Publications Warehouse

    DeSorcie, Timothy J.; Bowen, Charles A., II

    2003-01-01

    Six Fathom Bank-Yankee Reef, an offshore reef complex, was an historically important spawning area believed to represent some of the best habitat for the rehabilitation of lake trout Salvelinus namaycush in Lake Huron. Since 1986, lake trout have been stocked on these offshore reefs to reestablish self-sustaining populations. We sampled with beam trawls to determine the abundance of naturally reproduced age-0 lake trout on these offshore reefs during May-July in 1994-1998 and 2000-2002. In total, 123 naturally reproduced lake trout fry were caught at Six Fathom Bank, and 2 naturally reproduced lake trout fry were caught at nearby Yankee Reef. Our findings suggest that this region of Lake Huron contains suitable habitat for lake trout spawning and offers hope that lake trout rehabilitation can be achieved in the main basin of Lake Huron.

  19. Lake whitefish and lake herring population structure and niche in ten south-central Ontario lakes

    USGS Publications Warehouse

    Carl, Leon M.; McGuiness, Fiona

    2006-01-01

    This study compares simple fish communities of ten oligotrophic lakes in south-central Ontario. Species densities and population size structure vary significantly among these lake communities depending on fish species present beyond the littoral zone. Lake whitefish are fewer and larger in the presence of lake herring than in their absence. Diet analysis indicates that lake whitefish shift from feeding on both plankton and benthic prey when lake herring are absent to a primarily benthic feeding niche in the presence of lake herring. When benthic round whitefish are present, lake whitefish size and density decline and they move lower in the lake compared to round whitefish. Burbot are also fewer and larger in lakes with lake herring than in lakes without herring. Burbot, in turn, appear to influence the population structure of benthic coregonine species. Lower densities of benthic lake whitefish and round whitefish are found in lakes containing large benthic burbot than in lakes with either small burbot or where burbot are absent. Predation on the pelagic larvae of burbot and lake whitefish by planktivorous lake herring alters the size and age structure of these populations. As life history theory predicts, those species with poor larval survival appear to adopt a bet-hedging life history strategy of long-lived individuals as a reproductive reserve.

  20. Lake sturgeon population characteristics in Rainy Lake, Minnesota and Ontario

    USGS Publications Warehouse

    Adams, W.E., Jr.; Kallemeyn, L.W.; Willis, D.W.

    2006-01-01

    Rainy Lake contains a native population of lake sturgeon Acipenser fulvescens that has been largely unstudied. The aims of this study were to document the population characteristics of lake sturgeon in Rainy Lake and to relate environmental factors to year-class strength for this population. Gill-netting efforts throughout the study resulted in the capture of 322 lake sturgeon, including 50 recaptures. Lake sturgeon in Rainy Lake was relatively plump and fast growing compared with a 32-population summary. Population samples were dominated by lake sturgeon between 110 and 150 cm total length. Age–structure analysis of the samples indicated few younger (<10 years) lake sturgeon, but the smallest gill net mesh size used for sampling was 102 mm (bar measure) and would not retain small sturgeon. Few lake sturgeon older than age 50 years were captured, and maximum age of sampled fish was 59 years. Few correlations existed between lake sturgeon year-class indices and both annual and monthly climate variables, except that mean June air temperature was positively correlated with year-class strength. Analysis of Rainy Lake water elevation and resulting lake sturgeon year-class strength indices across years yielded consistent but weak negative correlations between late April and early June, when spawning of lake sturgeon occurs. The baseline data collected in this study should allow Rainy Lake biologists to establish more specific research questions in the future.

  1. 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

  2. Yellowstone Lake Nanoarchaeota

    PubMed Central

    Clingenpeel, Scott; Kan, Jinjun; Macur, Richard E.; Woyke, Tanja; Lovalvo, Dave; Varley, John; Inskeep, William P.; Nealson, Kenneth; McDermott, Timothy R.

    2013-01-01

    Considerable Nanoarchaeota novelty and diversity were encountered in Yellowstone Lake, Yellowstone National Park (YNP), where sampling targeted lake floor hydrothermal vent fluids, streamers and sediments associated with these vents, and in planktonic photic zones in three different regions of the lake. Significant homonucleotide repeats (HR) were observed in pyrosequence reads and in near full-length Sanger sequences, averaging 112 HR per 1349 bp clone and could confound diversity estimates derived from pyrosequencing, resulting in false nucleotide insertions or deletions (indels). However, Sanger sequencing of two different sets of PCR clones (110 bp, 1349 bp) demonstrated that at least some of these indels are real. The majority of the Nanoarchaeota PCR amplicons were vent associated; however, curiously, one relatively small Nanoarchaeota OTU (71 pyrosequencing reads) was only found in photic zone water samples obtained from a region of the lake furthest removed from the hydrothermal regions of the lake. Extensive pyrosequencing failed to demonstrate the presence of an Ignicoccus lineage in this lake, suggesting the Nanoarchaeota in this environment are associated with novel Archaea hosts. Defined phylogroups based on near full-length PCR clones document the significant Nanoarchaeota 16S rRNA gene diversity in this lake and firmly establish a terrestrial clade distinct from the marine Nanoarcheota as well as from other geographical locations. PMID:24062731

  3. LAKE RESTORATION BY DILUTION: MOSES LAKE, WASHINGTON

    EPA Science Inventory

    Dilution water, low in macronutrients, was added to Moses Lake on three occasions in 1977 and once in 1978 during the spring-summer period. The addition resulted in reducing the annual average inflow concentration of phosphorus from about 130-140 micrograms/l to 100 micrograms/l....

  4. Lake Mead, NV

    NASA Technical Reports Server (NTRS)

    1973-01-01

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

  5. Can lake sensitivity to desiccation be predicted from lake geometry?

    NASA Astrophysics Data System (ADS)

    Torabi Haghighi, Ali; Menberu, Meseret Walle; Aminnezhad, Mousa; Marttila, Hannu; Kløve, Bjørn

    2016-08-01

    Declining lake levels (Aral Sea syndrome) can be caused by changes in climate, increased water use or changed regulation patterns. This paper introduces a novel lake geometry index (LGI) to quantify lake hydrological characteristics. The index was developed using a large representative dataset of lake hypsographic characteristics from 152 lakes and man-made reservoirs. Using the LGI index, lakes can be classified into five groups: groups 1-4 when LGI is 0.5-2.5, 2.5-4.5, 4.5-6.5 and 6.5-8.5, respectively, and group 5 when LGI is >8.5. Naturally shallow and vast lakes and wetlands fall into the first group and deep man-made reservoirs in narrow valleys are in group 5. The response of three different lake systems (LGI 0.75, 2.75 and 6.5) to different water flow scenarios was then simulated using the water balance equation. From this, the index 'potential lake area' (Apot) was developed to show lake responses to changed hydro-climatological conditions. Apot and LGI can be used to classify lakes into open or closed systems. Simulations showed that lakes with low LGI have a shorter response time to flow and climate changes. As a result, the impact of water balance restoration is faster for lakes with low LGI than for lakes with high LGI. The latter are also more vulnerable to climate variation and change.

  6. The pool of organic carbon and its isotopic composition in cryomorphic quasi-gley chernozems of the Trans-Baikal region

    NASA Astrophysics Data System (ADS)

    Tsybenov, Yu. B.; Chimitdorzhieva, G. D.; Egorova, R. A.; Gongal'skii, K. B.

    2016-01-01

    Quasi-gley chernozems of the Trans-Baikal region are characterized by the clearly pronounced anisotropy of their properties related to carbon sequestration processes. The main carbon pool is concentrated in the humus horizon; the organic carbon content sharply decreases down the soil profile. The pool of organic carbon in the cryogenic fissures is two to three times higher than its pool in the enclosing soil horizons. The analysis of stable carbon isotopes in the plants and soils attests to the predominance of C3 plants. The composition of stable carbon isotopes is clearly differentiated in the soil profile with an increase in the portion of heavy isotopes in the deep horizons. In the humus pockets and cryogenic fissures, the increase in the portion of heavy carbon isotopes with the depth is weaker, which attests to a lower degree of the organic matter transformation. It is probable that the organic matter in the fissures is younger than the organic matter in the enclosing soil mass and derives from the upper humus horizon. The organic matter in the cryogenic fissures preserves the evolutionary properties of humus from the upper horizons.

  7. Paleopathological Description and Diagnosis of Metastatic Carcinoma in an Early Bronze Age (4588+34 Cal. BP) Forager from the Cis-Baikal Region of Eastern Siberia

    PubMed Central

    Lieverse, Angela R.; Temple, Daniel H.; Bazaliiskii, Vladimir I.

    2014-01-01

    Extensive osteolytic and osteoblastic lesions were observed on the skeletal remains of an adult male excavated from an Early Bronze Age cemetery dated to 4556+32 years BP, located in the Cis-Baikal region of Siberia (Russian Federation). Lytic lesions ranged in size from several mm to over 60 mm in diameter and had irregular, moth-eaten borders. Many of these lesions destroyed trabecular bone, though a hollowed shell of cortical bone often remained observable. Radiographic analysis revealed numerous lytic lesions within trabecular bone that had not yet affected the cortex. Blastic lesions were identified as spiculated lines, bands, or nodules of mostly immature (woven) bone formed at irregular intervals. Anatomical elements with the greatest involvement included those of the axial skeleton (skull, vertebrae, sacrum, ribs, and sternum) as well as proximal appendicular elements (ossa coxae, proximal femora, clavicles, scapulae, and proximal humeri). Osteocoalescence of destructive foci was observed on the ilium and frontal bone, with the largest lesion found on the right ilium. Differential diagnoses include metastatic carcinoma, mycotic infections, tuberculosis, Langerhan's cell histiocytosis, and multiple myeloma. Based on lesion appearance and distribution, age and sex of the individual, as well as pathogen endemism, the most likely diagnostic option for this set of lesions is metastatic carcinoma. The age and sex of this individual and appearance of the lesions may reflect carcinoma of the lung or, possibly, prostate. This represents one of the earliest cases of metastatic carcinoma worldwide and the oldest case documented thus far from Northeast Asia. PMID:25470373

  8. [Distinctive Features of the Microbial Diversity and the Polyketide Synthase GenesSpectrum in the Community of the Endemic Baikal Sponge Swartschewskia papyracea].

    PubMed

    Kaluzhnaya, O V; Itskovich, V B

    2016-01-01

    The diversity of the symbiotic community of the endemic Baikal sponge Swartschewskia papyracea was studied, and an analysis of the polyketide synthases genes spectrum in sponge-associated microorganisms was carried out. Six bacterial phyla were detected in the S. papyracea microbiome, namely, Verrucomicrobia, Cyanobacteria, Actinobacteria, Bacteroidetes, Proteobacteria, and Planctomycetes. Unlike the microbial associations of other freshwater sponges, the community under study was dominated by the Verrucomicrobia (42.1%) and Cyanobacteria (17.5%) phyla, while the proportion of the Proteobacteria was unusually low (9.7%). In the S. papyracea community metagenome, there were identified 18 polyketide synthases genes fragments, the closest homologs of which included the polyketide synthases of the microorganisms belonging to the bacterial phyla Cyanobacteria, Proteobacteria (Betaproteobacteria, Deltaproteobacteria, and Gammaproteobacteria classes), and Acidobacteria and to the eukaryotic algae of the Heterokonta phylum (Eustigmatophyceae class). Polyketide synthase sequences from S. papyracea formed three groups on the phylogenetic tree: a group of hybrid NRPS/PKS complexes, a group of cyanobacterial polyketide synthases, and a group of homologs of the eukaryotic alga Nannochloropsis galiana. Notably, the identified polyketide synthase genes fragments showed only a 57-88% similarity to the sequences in the databases, which implies the presence of genes controlling the synthesis of the novel, still unstudied, polyketide compounds in the S. papyracea community. It was proposed that the habitation conditions of S. papyracea affect the taxonomic composition of the microorganisms associated with the sponge, including the diversity of the producers of secondary metabolites. PMID:27183792

  9. Paleopathological description and diagnosis of metastatic carcinoma in an Early Bronze Age (4588+34 Cal. BP) forager from the Cis-Baikal region of Eastern Siberia.

    PubMed

    Lieverse, Angela R; Temple, Daniel H; Bazaliiskii, Vladimir I

    2014-01-01

    Extensive osteolytic and osteoblastic lesions were observed on the skeletal remains of an adult male excavated from an Early Bronze Age cemetery dated to 4556+32 years BP, located in the Cis-Baikal region of Siberia (Russian Federation). Lytic lesions ranged in size from several mm to over 60 mm in diameter and had irregular, moth-eaten borders. Many of these lesions destroyed trabecular bone, though a hollowed shell of cortical bone often remained observable. Radiographic analysis revealed numerous lytic lesions within trabecular bone that had not yet affected the cortex. Blastic lesions were identified as spiculated lines, bands, or nodules of mostly immature (woven) bone formed at irregular intervals. Anatomical elements with the greatest involvement included those of the axial skeleton (skull, vertebrae, sacrum, ribs, and sternum) as well as proximal appendicular elements (ossa coxae, proximal femora, clavicles, scapulae, and proximal humeri). Osteocoalescence of destructive foci was observed on the ilium and frontal bone, with the largest lesion found on the right ilium. Differential diagnoses include metastatic carcinoma, mycotic infections, tuberculosis, Langerhan's cell histiocytosis, and multiple myeloma. Based on lesion appearance and distribution, age and sex of the individual, as well as pathogen endemism, the most likely diagnostic option for this set of lesions is metastatic carcinoma. The age and sex of this individual and appearance of the lesions may reflect carcinoma of the lung or, possibly, prostate. This represents one of the earliest cases of metastatic carcinoma worldwide and the oldest case documented thus far from Northeast Asia. PMID:25470373

  10. Platinum group elements in gold-sulfide and base-metal ores of the Sayan-Baikal Fold Region and possible platinum and palladium speciation in sulfides

    NASA Astrophysics Data System (ADS)

    Mironov, A. G.; Zhmodik, S. M.; Kolesov, G. M.; Mit'kin, V. N.; Damdinov, B. B.; Zayakina, S. B.

    2008-02-01

    The concentration levels and distribution features of the platinum group elements (PGE) in quartz-sulfide and base-metal ores in deposits of the Sayan-Baikal Fold Region (SBFR) are discussed. Microfire assay neutron activation analysis (MF-NAA), which enables one to work on a nondestructive basis and allows one to avoid inaccuracies related to chemical sample preparation, was used as the main analytical technique. Three types of hydrothermal mineralization with elevated grades of PGE (especially Pt, Pd, and Ru) have been identified: (1) pyrite-pyrrhotite (massive sulfide) mineralization hosted in black shales of the Il’chir Sequence; (2) gold-sulfide ores of the Zun-Kholba, Tainsky, Kamenny, and some other gold deposits; and (3) silver-basemetal ores of the Dzhida-Vitim Zone. The PGE contents significantly vary, from global average values to tens of grams per ton. An absence of PGE minerals implies that these elements are finely dispersed in sulfide minerals and native gold. Taking into account difficulties in conversion of PGE into analytical forms, their nonuniform distribution in sulfide minerals, their high affinity to coordination compounds, and experimental results, cluster species of Pt and Pd in major minerals are suggested for the gold-sulfide and silver-base-metal ores in deposits, which are related to suprasubduction ophiolites and island-arc and intraplate settings in the SBFR.

  11. [FEATURES OF CONSTITUTIONAL CHARACTERISTICS OF YOUNG MALES AGED OF 17-20 YEARS, NATIVES OF THE BAIKAL REGION WITH REGARD TO THEIR FUNCTIONAL GROUPS OF HEALTH].

    PubMed

    Kolokoltsev, M M

    2016-01-01

    The study of somatotypes of the constitution is an important point in planning of the improvements of measures among the population in various regions of Russia. The purpose of the work was to reveal features of age dynamics of somatotypes of the constitution in students of youthful age of the Baikal Region by means of somatotyping according to scheme by Nikityuk B. A. and Kozlova A.I (1990) with taking into account their functional group of health. There were examined 1286 Slavic young males, natives of the Irkutsk region, aged of 17-20 years, from them, according to data of the medical examination 996 were referred to the 1st (main) and 290--to the 2nd (preparatory) functional group of health for physical exercises. There were established significant differences in somatotypes of the constitution in young men of the 1st and 2nd functional groups of health. In both functional groups there is noted a significant amount of young males with transitional somatotypes that testifies to incompleteness of growth processes of their organism. The obtained results of a somatotyping are used in the educational process for a training individualization on physical culture of students of IRGTU, and also in construction of independent physical--improving programs. PMID:27430074

  12. GREAT LAKES PLANKTON PROGRAM

    EPA Science Inventory

    Phytoplankton, which have short carbon turnover rates, are sensitive to water quality conditions and grazing by zooplankton, and thus respond rapidly to perturbations of the lake ecosystem. The determination of phytoplankton abundance and species composition is one method to tra...

  13. Is Lake Tahoe Terminal?

    NASA Astrophysics Data System (ADS)

    Coats, R. N.; Reuter, J.; Heyvaert, A.; Lewis, J.; Sahoo, G. B.; Schladow, G.; Thorne, J. H.

    2014-12-01

    Lake Tahoe, an iconic ultra-oligotrophic lake in the central Sierra Nevada, has been studied intensively since 1968, with the goal of understanding and ultimately controlling its eutrophication and loss of clarity. Research on the lake has included a) periodic profiles of primary productivity, nutrients, temperature, and plankton; b) Secchi depth; c) nutrient limitation experiments; d) analysis of sediment cores; e) radiocarbon dating of underwater in-place tree stumps; g) analysis of long-term temperature trends. Work in its watershed has included a) monitoring of stream discharge, sediment and nutrients at up to 20 stream gaging stations; b) monitoring of urban runoff water quality at selected sites; c) development of a GIS data base, including soils, vegetation, and land use. Based on these studies, we know that a) primary productivity in the lake is limited by phosphorus, and continues to increase; b) the loss of clarity continues, but at a declining rate; c) the lake has been warming since 1970, and its resistance to deep mixing is increasing; d) historically the lake level drops below the outlet elevation about one year in seven; e) 6300 to 4300 yrs BP lake level was below the present outlet elevation long enough for large trees to grow; f) the date of the peak snowmelt runoff is shifting toward earlier dates; g) after accounting for annual runoff, loads of nutrients and suspended sediment have declined significantly in some basin streams since 1980. Downscaled outputs from GCM climatic models have recently been used to drive hydrologic models and a lake clarity model, projecting future trends in the lake and watersheds. Results show a) the temperature and thermal stability will likely continue to increase, with deep mixing shutting down in the latter half of this century; b) the lake may drop below the outlet for an extended period beginning about 2085; c) the annual snowpack will continue to decline, with earlier snowmelt and shift from snowfall to rain; d

  14. Lake Superior, Duluth, MN

    NASA Technical Reports Server (NTRS)

    1973-01-01

    This view shows the west end of Lake Superior and Duluth, MN (47.0N, 91.0W). Portions of Minnesota, Michigan and Ontario, Canada are in the scene. The Duluth metropolitan area is at the west end of the lake. The discoloration plume in the water at Duluth is the result of tailings from the iron ore smelters that process the iron ore from the nearby open pit mines seen near the upper left corner of the photo.

  15. Lake Chad, Chad, Africa

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The fluctuating water levels of Lake Chad, (13.0N, 15.0E) at the intersection of the borders of Chad, Niger and Cameroon in the Sahara Desert, is an index of the drought in Africa. The lake level continues to decrease as indicated by the growing number and extent of emerging islands as previously submerged ancient sand dunes become visible. The water impounded between the dunes is probably because of local rainfall rather than a reversal of desertification.

  16. WHISKER LAKE WILDERNESS, WISCONSIN.

    USGS Publications Warehouse

    Schulz, Klaus J.

    1984-01-01

    The mineral-resource potential of the Whisker Lake Wilderness in northeastern Wisconsin was evaluated. Only a strip along the southwest corner of the wilderness is assessed as having probable mineral-resource potential. If mineral deposits exist, they probably are of the massive sulfide type. The geologic terrain precludes the presence of fossil fuel resources. Sand and gravel and peat in swampy lowlands are the only resources of the Whisker lake Wilderness.

  17. Dragon Lake, Siberia

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Nicknamed 'Dragon Lake,' this body of water is formed by the Bratskove Reservoir, built along the Angara river in southern Siberia, near the city of Bratsk. This image was acquired in winter, when the lake is frozen. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on December 19, 1999. This is a natural color composite image made using blue, green, and red wavelengths. Image provided by the USGS EROS Data Center Satellite Systems Branch

  18. Salt Lake City, Utah

    NASA Technical Reports Server (NTRS)

    2002-01-01

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

  19. Is Lake Chabot Eutrophic?

    NASA Astrophysics Data System (ADS)

    Pellegrini, K.; Logan, J.; Esterlis, P.; Lew, A.; Nguyen, M.

    2013-12-01

    Introduction/Abstract: Lake Chabot is an integral part of the East Bay watershed that provides habitats for animals and recreation for humans year-round. Lake Chabot has been in danger of eutrophication due to excessive dumping of phosphorous and nitrogen into the water from the fertilizers of nearby golf courses and neighboring houses. If the lake turned out to be eutrophified, it could seriously impact what is currently the standby emergency water supply for many Castro Valley residents. Eutrophication is the excessive richness of nutrients such as nitrogen and phosphorus in a lake, usually as a result of runoff. This buildup of nutrients causes algal blooms. The algae uses up most of the oxygen in the water, and when it dies, it causes the lake to hypoxify. The fish in the lake can't breathe, and consequently suffocate. Other oxygen-dependant aquatic creatures die off as well. Needless to say, the eutrophication of a lake is bad news for the wildlife that lives in or around it. The level of eutrophication in our area in Northern California tends to increase during the late spring/early summer months, so our crew went out and took samples of Lake Chabot on June 2. We focused on the area of the lake where the water enters, known on the map as Honker Bay. We also took readings a ways down in deeper water for comparison's sake. Visually, the lake looked in bad shape. The water was a murky green that glimmered with particulate matter that swirled around the boat as we went by. In the Honker Bay region where we focused our testing, there were reeds bathed in algae that coated the surface of the lake in thick, swirling patterns. Surprisingly enough, however, our test results didn't reveal any extreme levels of phosphorous or nitrogen. They were slightly higher than usual, but not by any significant amount. The levels we found were high enough to stimulate plant and algae growth and promote eutrophication, but not enough to do any severe damage. After a briefing with a

  20. Availability of lake trout reproductive habitat in the Great Lakes

    USGS Publications Warehouse

    Edsall, Thomas A.; Kennedy, Gregory W.

    1995-01-01

    A decades-long program to reestablish self-sustaining stocks of lake trout (Salvelinus namaycush) in the four lower Great Lakes produced excellent fisheries supported by stocked fish. These fish spawned widely and small numbers of their offspring were collected intermittently from Lakes Michigan, Huron, and Ontario, but no self-sustaining stocks were established. Irt this paper we address habitat sufficiency as a factor in the failure of stocked lake trout to established self-sustaining populations in the four lower Great Lakes. We present the previously unpublished results of lake trout spawning habitat surveys conducted at seven sites in the Great Lakes since 1987 and we compare them with the published results of similar surveys conducted at 24 other sites in the four lower lakes since 1981. Our evaluation indicates all but two of these sites can support the production of viable fry from spawnings by the shallow-water strains of lake trout that are stocked in the Great Lakes. However, some of the best spawning, egg, and fry habitat in the lower Great Lakes seems to be at deeper offshore sites that may be unattractive to these shallow-water strains. Thus, we suggest also stocking the lower four lakes with strains from Lake Superior that might more fully exploit the best spawning habitat at these deeper, offshore sites.

  1. Contaminants in American alligator eggs from Lake Apopka, Lake Griffin, and Lake Okeechobee, Florida

    USGS Publications Warehouse

    Heinz, G.H.; Percival, H.F.; Jennings, Michael L.

    1991-01-01

    Residues of organochlorine pesticides, polychlorinated biphenyls (PCBs), and 16 elements were measured in American alligator (Alligator mississippiensis) eggs collected in 1984 from Lakes Apopka, Griffin, and Okeechobee in central and south Florida. Organochlorine pesticides were highest in eggs from Lake Apopka. None of the elements appeared to be present at harmful concentrations in eggs from any of the lakes. A larger sample of eggs was collected in 1985, but only from Lakes Griffin, a lake where eggs were relatively clean, and Apopka, where eggs were most contaminated. In 1985, hatching success of artificially incubated eggs was lower for Lake Apopka, and several organochlorine pesticides were higher than in eggs from Lake Griffin. However, within Lake Apopka, higher levels of pesticides in chemically analyzed eggs were not associated with reduced hatching success of the remaining eggs in the clutch. Therefore, it did not appear that any of the pesticides we measured were responsible for the reduced hatching of Lake Apopka eggs.

  2. Big lake records preserved in a little lake's sediment: An example from Silver Lake, Michigan, USA

    USGS Publications Warehouse

    Fisher, T.G.; Loope, W.L.; Pierce, W.; Jol, H.M.

    2007-01-01

    We reconstruct postglacial lake-level history within the Lake Michigan basin using soil stratigraphy, ground-penetrating radar (GPR), sedimentology and 14C data from the Silver Lake basin, which lies adjacent to Lake Michigan. Stratigraphy in nine vibracores recovered from the floor of Silver Lake appears to reflect fluctuation of water levels in the Lake Michigan basin. Aeolian activity within the study area from 3,000 years (cal yr. B.P.) to the present was inferred from analysis of buried soils, an aerial photograph sequence, and GPR. Sediments in and around Silver Lake appear to contain a paleoenvironmental record that spans the entire post-glacial history of the Lake Michigan basin. We suggest that (1) a pre-Nipissing rather than a Nipissing barrier separated Silver Lake basin from the Lake Michigan basin, (2) that the Nipissing transgression elevated the water table in the Silver Lake basin about 6,500 cal yr. B.P., resulting in reestablishment of a lake within the basin, and (3) that recent dune migration into Silver Lake is associated with levels of Lake Michigan.

  3. Evidence of Lake Trout reproduction at Lake Michigan's mid-lake reef complex

    USGS Publications Warehouse

    Janssen, J.; Jude, D.J.; Edsall, T.A.; Paddock, R.W.; Wattrus, N.; Toneys, M.; McKee, P.

    2006-01-01

    The Mid-Lake Reef Complex (MLRC), a large area of deep (> 40 m) reefs, was a major site where indigenous lake trout (Salvelinus namaycush) in Lake Michigan aggregated during spawning. As part of an effort to restore Lake Michigan's lake trout, which were extirpated in the 1950s, yearling lake trout have been released over the MLRC since the mid-1980s and fall gill net censuses began to show large numbers of lake trout in spawning condition beginning about 1999. We report the first evidence of viable egg deposition and successful lake trout fry production at these deep reefs. Because the area's existing bathymetry and habitat were too poorly known for a priori selection of sampling sites, we used hydroacoustics to locate concentrations of large fish in the fall; fish were congregating around slopes and ridges. Subsequent observations via unmanned submersible confirmed the large fish to be lake trout. Our technological objectives were driven by biological objectives of locating where lake trout spawn, where lake trout fry were produced, and what fishes ate lake trout eggs and fry. The unmanned submersibles were equipped with a suction sampler and electroshocker to sample eggs deposited on the reef, draw out and occasionally catch emergent fry, and collect egg predators (slimy sculpin Cottus cognatus). We observed slimy sculpin to eat unusually high numbers of lake trout eggs. Our qualitative approaches are a first step toward quantitative assessments of the importance of lake trout spawning on the MLRC.

  4. Winter Lake Breezes near the Great Salt Lake

    NASA Astrophysics Data System (ADS)

    Crosman, Erik T.; Horel, John D.

    2016-05-01

    Case studies of lake breezes during wintertime cold air pools in Utah's Salt Lake Valley are examined. While summer breezes originating from the Great Salt Lake are typically deeper, of longer duration, and have higher wind speeds than winter breezes, the rate of inland penetration and cross-frontal temperature differences can be higher during the winter. The characteristics of winter breezes and the forcing mechanisms controlling them (e.g., snow cover, background flow, vertical stability profile, clouds, lake temperature, lake sheltering, and drainage pooling) are more complex and variable than those evident in summer. During the afternoon in the Salt Lake Valley, these lake breezes can lead to elevated pollution levels due to the transport of fine particle pollutants from over the Great Salt Lake, decreased vertical mixing depth, and increased vertical stability.

  5. Inorganic data from El'gygytgyn Lake sediments: stages 6-11

    NASA Astrophysics Data System (ADS)

    Minyuk, P. S.; Borkhodoev, V. Ya.; Wennrich, V.

    2013-01-01

    Geochemical study was performed on sediment of deep drilling core from El'gygytgyn Lake, located in central Chukotka, northeastern Russia (67°30' N; 172°05' E). Major and rare elements were determined by X-ray fluorescence spectroscopy (XRF) on 600 samples covering the timeframe between ca. 450 and 125 ka corresponding to Marine Isotope Stages (MIS) 11 to 6. Inorganic geochemistry data indicates significant variations in the elemental compositions corresponding to the glacials and interglacials periods. Interglacial sediments are characterized by high contents of SiO2, Na2O, CaO, K2O, Sr and are depleted in Al2O3, Fe2O3, TiO2, MgO. Extreme enrichments in SiO2 during MIS 11.3 and 9.3 are caused by an enhanced flux of biogenic silica (BSi). Geochemical structure of stage 11 shows very similar peculiarities to features of stage 11 from records of Lake Baikal/SE Siberia and Antarctic ice cores. High contents of TiO2, Fe2O3, MgO, Al2O3, LOI, Ni, Cr and Zr are typical for sediments of glacial stages, among those MIS 7.4 and 6.6 are the most marked. Peaks in the Fe2O3 content and coinciding low Fe2O3/MnO ratios during glacials indicate reducing condition in the sediments. This is also supported by enrichments in P2O5 and MnO, indicating an increased abundance of authigenic fine grained vivianite. Some elemental ratios indicate an enhanced alteration of glacial sediments accompanied by a loss of mobile elements, like Na, Ca, K and Sr. The higher alteration of sediments can presumably be traced back to changes in the sedimentation regime and diagenetic processes, and thus, reflects environmental changes.

  6. Inorganic geochemistry data from Lake El'gygytgyn sediments: marine isotope stages 6-11

    NASA Astrophysics Data System (ADS)

    Minyuk, P. S.; Borkhodoev, V. Y.; Wennrich, V.

    2014-03-01

    Geochemical analyses were performed on sediments recovered by deep drilling at Lake El'gygytgyn in central Chukotka, northeastern Russia (67°30' N; 172°05' E). Major and rare element concentrations were determined using X-ray fluorescence spectroscopy (XRF) on the < 250 μm fraction from 617 samples dated to ca. 440 and 125 ka, which approximates marine isotope stages (MIS) 11 to 6. The inorganic geochemistry indicates significant variations in elemental composition between glaciations and interglaciations. Interglacial sediments are characterized by high contents of SiO2, Na2O, CaO, K2O, and Sr and are depleted in Al2O3, Fe2O3, TiO2, and MgO. An extreme SiO2 enrichment during MIS 11.3 and 9.3 was caused by an enhanced flux of biogenic silica (BSi). The geochemical structure of MIS 11 shows similar characteristics as seen in MIS 11 records from Lake Baikal (southeastern Siberia) and Antarctic ice cores, thereby arguing for the influence of global forcings on these records. High sediment content of TiO2, Fe2O3, MgO, Al2O3, LOI, Ni, Cr, and Zr typifies glacial stages, with the most marked increases during MIS 7.4 and 6.6. Reducing conditions during glacial times are indicated by peaks in the Fe2O3 content and coinciding low Fe2O3/MnO ratios. This conclusion also is supported by P2O5 and MnO enrichment, indicating an increased abundance of authigenic, fine-grained vivianite. Elemental ratios (CIA, CIW, PIA, and Rb/Sr) indicate that glacial sediments are depleted in mobile elements, like Na, Ca, K and Sr. This depletion was caused by changes in the sedimentation regime and thus reflects environmental changes.

  7. 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.

  8. The Wandering Lake

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In the area at the very far eastern corner of China's Taklimakan Desert, Lop Nor Lake was located up until some years ago. Lop Nor, also called the 'the heart of the heart' of Asia, was the place where the waters of the largest inner basin (i.e., not flowing into the sea) of the world-including the Tarim and Kum-daria Rivers-were collected. Depending on the balance between rainfall water yield and evaporation, both position and size of the lake were strongly variable, thus giving rise to the legend of the Wandering Lake. 'Lop City' was the place where Marco Polo took his last rest before facing the one-year long crossing of the Gobi Desert. Starting from the end of the 19th century, several explorers tried to find the legendary place. One such explorer was Sven Hedin, who was commissioned by the Governor of Nanjing to lead an expedition to find the lake. In 1937, the Swedish explorer published his book entitled The Wandering Lake. Comparing this very precise map from Sven Hedin's book with the above Moderate-resolution Imaging Spectroradiometer (MODIS) false-color image (acquired on October 28, 2001), one can find a faint sign on the soil where the Lop Nor was located. This image, derived using a combination of MODIS' near-infrared and red channels (vegetation in red), shows where the Tarim River waters currently end their flow. The Wandering Lake does not exist anymore. The combination of climate change and human exploitation of water resources for agriculture caused the disappearance of the lake. This image was processed by Telespazio, Earth Observation division, new products development facility in Rome, Italy. The MODIS sensor flies aboard NASA's Terra spacecraft, launched in December 1999. Caption and image courtesy Luca Pietranera, Telespazio, Rome, Italy, based on data from the MODIS Science Team

  9. 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.

  10. Examining indirect effects of lake trout recovery

    EPA Science Inventory

    With the recovery of lake trout populations in Lake Superior, there are indications of decreased forage fish abundance and density-dependence in lake trout. In Lake Superior, lean lake trout historically occupied depths < 60 m, and siscowet lake trout occupied depths > 60 m...

  11. View of Lake Sabrina Dam and dry Lake Sabrina Basin ...

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

    View of Lake Sabrina Dam and dry Lake Sabrina Basin with the upstream side of the outlet structure visible at photo center, view to north-northwest - Bishop Creek Hydroelectric System, Plant 2, Lake Sabrina Dam, Bishop Creek, Bishop, Inyo County, CA

  12. 42. Peaks of Otter, Abbott Lake. View across lake to ...

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

    42. Peaks of Otter, Abbott Lake. View across lake to peaks of Outter Lodge, completed in 1964. Construction of the lake got underway in 1964. Looking east-northeast. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  13. Lake Michigan lake trout PCB model forecast post audit

    EPA Science Inventory

    Scenario forecasts for total PCBs in Lake Michigan (LM) lake trout were conducted using the linked LM2-Toxics and LM Food Chain models, supported by a suite of additional LM models. Efforts were conducted under the Lake Michigan Mass Balance Study and the post audit represents th...

  14. Mono Lake Excursion Reviewed

    NASA Astrophysics Data System (ADS)

    Liddicoat, J. C.; Coe, R. S.

    2007-05-01

    The Mono Lake Excursion as recorded in the Mono Basin, CA, has an older part that is about negative 30 degrees inclination and about 300 degrees declination during low relative field intensity. Those paleomagnetic directions are closely followed by greater than 80 degrees positive inclination and east declination of about 100 degrees during higher relative field intensity. A path of the Virtual Geomagnetic Poles (VGPs) for the older part followed from old to young forms a large clockwise loop that reaches 35 degrees N latitude and is centered at about 35 degrees E longitude. That loop is followed by a smaller one that is counterclockwise and centered at about 70 degrees N latitude and 270 degrees E longitude (Denham & Cox, 1971; Denham, 1974; Liddicoat & Coe, 1979). The Mono Lake Excursion outside the Mono Basin in western North America is recorded as nearly the full excursion at Summer Lake, OR (Negrini et al., 1984), and as the younger portion of steep positive inclination/east declination in the Lahontan Basin, NV. The overall relative field intensity during the Mono Lake Excursion in the Lahontan Basin mirrors very closely the relative field intensity in the Mono Basin (Liddicoat, 1992, 1996; Coe & Liddicoat, 1994). Using 14C and 40Ar/39Ar dates (Kent et al., 2002) and paleoclimate and relative paleointensity records (Zimmerman et al., 2006) for the Mono Lake Excursion in the Mono Basin, it has been proposed that the Mono Lake Excursion might be older than originally believed and instead be the Laschamp Excursion at about 40,000 yrs B.P. (Guillou et al., 2004). On the contrary, we favor a younger age for the Mono Lake Excursion, about 32,000 yrs B.P., using the relative paleointensity in the Mono Basin and Lahontan Basin and 14C dates from the Lahontan Basin (Benson et al., 2002). The age of about 32,000 yrs B.P. is also in accord with the age (32,000- 34,000 yrs B.P.) reported by Channell (2006) for the Mono Lake Excursion at ODP Site 919 in the Irminger Basin

  15. 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. PMID:27104923

  16. Michigan: The Great Lakes State

    ERIC Educational Resources Information Center

    McKay, Sandra Lee; La Luzerne-Oi, Sally

    2009-01-01

    Although Michigan is often called the "Wolverine State," its more common nickname is the "Great Lakes State." This name comes from the fact that Michigan is the only state in the United States that borders four of the five Great Lakes. Also referred to as the "Water Wonderland," Michigan has 11,000 additional lakes, 36,000 miles of streams, and…

  17. Viruses in Antarctic lakes

    NASA Technical Reports Server (NTRS)

    Kepner, R. L. Jr; Wharton, R. A. Jr; Suttle, C. A.; Wharton RA, J. r. (Principal Investigator)

    1998-01-01

    Water samples collected from four perennially ice-covered Antarctic lakes during the austral summer of 1996-1997 contained high densities of extracellular viruses. Many of these viruses were found to be morphologically similar to double-stranded DNA viruses that are known to infect algae and protozoa. These constitute the first observations of viruses in perennially ice-covered polar lakes. The abundance of planktonic viruses and data suggesting substantial production potential (relative to bacteria] secondary and photosynthetic primary production) indicate that viral lysis may be a major factor in the regulation of microbial populations in these extreme environments. Furthermore, we suggest that Antarctic lakes may be a reservoir of previously undescribed viruses that possess novel biological and biochemical characteristics.

  18. The Ancestral Carnivore Karyotype As Substantiated by Comparative Chromosome Painting of Three Pinnipeds, the Walrus, the Steller Sea Lion and the Baikal Seal (Pinnipedia, Carnivora)

    PubMed Central

    Beklemisheva, Violetta R.; Perelman, Polina L.; Lemskaya, Natalya A.; Kulemzina, Anastasia I.; Proskuryakova, Anastasia A.; Burkanov, Vladimir N.; Graphodatsky, Alexander S.

    2016-01-01

    Karyotype evolution in Carnivora is thoroughly studied by classical and molecular cytogenetics and supplemented by reconstructions of Ancestral Carnivora Karyotype (ACK). However chromosome painting information from two pinniped families (Odobenidae and Otariidae) is noticeably missing. We report on the construction of the comparative chromosome map for species from each of the three pinniped families: the walrus (Odobenus rosmarus, Odobenidae–monotypic family), near threatened Steller sea lion (Eumetopias jubatus, Otariidae) and the endemic Baikal seal (Pusa sibirica, Phocidae) using combination of human, domestic dog and stone marten whole-chromosome painting probes. The earliest karyological studies of Pinnipedia showed that pinnipeds were characterized by a pronounced karyological conservatism that is confirmed here with species from Phocidae, Otariidae and Odobenidae sharing same low number of conserved human autosomal segments (32). Chromosome painting in Pinnipedia and comparison with non-pinniped carnivore karyotypes provide strong support for refined structure of ACK with 2n = 38. Constructed comparative chromosome maps show that pinniped karyotype evolution was characterized by few tandem fusions, seemingly absent inversions and slow rate of genome rearrangements (less then one rearrangement per 10 million years). Integrative comparative analyses with published chromosome painting of Phoca vitulina revealed common cytogenetic signature for Phoca/Pusa branch and supports Phocidae and Otaroidea (Otariidae/Odobenidae) as sister groups. We revealed rearrangements specific for walrus karyotype and found the chromosomal signature linking together families Otariidae and Odobenidae. The Steller sea lion karyotype is the most conserved among three studied species and differs from the ACK by single fusion. The study underlined the strikingly slow karyotype evolution of the Pinnipedia in general and the Otariidae in particular. PMID:26821159

  19. The Ancestral Carnivore Karyotype As Substantiated by Comparative Chromosome Painting of Three Pinnipeds, the Walrus, the Steller Sea Lion and the Baikal Seal (Pinnipedia, Carnivora).

    PubMed

    Beklemisheva, Violetta R; Perelman, Polina L; Lemskaya, Natalya A; Kulemzina, Anastasia I; Proskuryakova, Anastasia A; Burkanov, Vladimir N; Graphodatsky, Alexander S

    2016-01-01

    Karyotype evolution in Carnivora is thoroughly studied by classical and molecular cytogenetics and supplemented by reconstructions of Ancestral Carnivora Karyotype (ACK). However chromosome painting information from two pinniped families (Odobenidae and Otariidae) is noticeably missing. We report on the construction of the comparative chromosome map for species from each of the three pinniped families: the walrus (Odobenus rosmarus, Odobenidae-monotypic family), near threatened Steller sea lion (Eumetopias jubatus, Otariidae) and the endemic Baikal seal (Pusa sibirica, Phocidae) using combination of human, domestic dog and stone marten whole-chromosome painting probes. The earliest karyological studies of Pinnipedia showed that pinnipeds were characterized by a pronounced karyological conservatism that is confirmed here with species from Phocidae, Otariidae and Odobenidae sharing same low number of conserved human autosomal segments (32). Chromosome painting in Pinnipedia and comparison with non-pinniped carnivore karyotypes provide strong support for refined structure of ACK with 2n = 38. Constructed comparative chromosome maps show that pinniped karyotype evolution was characterized by few tandem fusions, seemingly absent inversions and slow rate of genome rearrangements (less then one rearrangement per 10 million years). Integrative comparative analyses with published chromosome painting of Phoca vitulina revealed common cytogenetic signature for Phoca/Pusa branch and supports Phocidae and Otaroidea (Otariidae/Odobenidae) as sister groups. We revealed rearrangements specific for walrus karyotype and found the chromosomal signature linking together families Otariidae and Odobenidae. The Steller sea lion karyotype is the most conserved among three studied species and differs from the ACK by single fusion. The study underlined the strikingly slow karyotype evolution of the Pinnipedia in general and the Otariidae in particular. PMID:26821159

  20. Transient Tsunamis in Lakes

    NASA Astrophysics Data System (ADS)

    Couston, L.; Mei, C.; Alam, M.

    2013-12-01

    A large number of lakes are surrounded by steep and unstable mountains with slopes prone to failure. As a result, landslides are likely to occur and impact water sitting in closed reservoirs. These rare geological phenomena pose serious threats to dam reservoirs and nearshore facilities because they can generate unexpectedly large tsunami waves. In fact, the tallest wave experienced by contemporary humans occurred because of a landslide in the narrow bay of Lituya in 1958, and five years later, a deadly landslide tsunami overtopped Lake Vajont's dam, flooding and damaging villages along the lakefront and in the Piave valley. If unstable slopes and potential slides are detected ahead of time, inundation maps can be drawn to help people know the risks, and mitigate the destructive power of the ensuing waves. These maps give the maximum wave runup height along the lake's vertical and sloping boundaries, and can be obtained by numerical simulations. Keeping track of the moving shorelines along beaches is challenging in classical Eulerian formulations because the horizontal extent of the fluid domain can change over time. As a result, assuming a solid slide and nonbreaking waves, here we develop a nonlinear shallow-water model equation in the Lagrangian framework to address the problem of transient landslide-tsunamis. In this manner, the shorelines' three-dimensional motion is part of the solution. The model equation is hyperbolic and can be solved numerically by finite differences. Here, a 4th order Runge-Kutta method and a compact finite-difference scheme are implemented to integrate in time and spatially discretize the forced shallow-water equation in Lagrangian coordinates. The formulation is applied to different lake and slide geometries to better understand the effects of the lake's finite lengths and slide's forcing mechanism on the generated wavefield. Specifically, for a slide moving down a plane beach, we show that edge-waves trapped by the shoreline and free

  1. Reevaluation of lake trout and lake whitefish bioenergetics models

    USGS Publications Warehouse

    Madenjian, Charles P.; Pothoven, Steve A.; Kao, Yu-Chun

    2013-01-01

    Using a corrected algorithm for balancing the energy budget, we reevaluated the Wisconsin bioenergetics model for lake trout (Salvelinus namaycush) in the laboratory and for lake whitefish (Coregonus clupeaformis) in the laboratory and in the field. For lake trout, results showed that the bioenergetics model slightly overestimated food consumption by the lake trout when they were fed low and intermediate rations, whereas the model predicted food consumption by lake trout fed ad libitum without any detectable bias. The slight bias in model predictions for lake trout on restricted rations may have been an artifact of the feeding schedule for these fish, and we would therefore recommend application of the Wisconsin lake trout bioenergetics model to lake trout populations in the field without any revisions to the model. Use of the Wisconsin bioenergetics model for coregonids resulted in overestimation of food consumption by lake whitefish both in the laboratory and in the field by between 20 and 30%, on average. This overestimation of food consumption was most likely due to overestimation of respiration rate. We therefore adjusted the respiration component of the bioenergetics model to obtain a good fit to the observed consumption in our laboratory tanks. The adjusted model predicted the consumption in the laboratory and the field without any detectable bias. Until a detailed lake whitefish respiration study can be conducted, we recommend application of our adjusted version of the Wisconsin generalized coregonid bioenergetics model to lake whitefish populations in the field.

  2. Maturity schedules of lake trout in Lake Michigan

    USGS Publications Warehouse

    Madenjian, Charles P.; DeSorcie, Timothy J.; Stedman, Ralph M.

    1998-01-01

    We determined maturity schedules of male and female lake trout (Salvelinus namaycush) in Lake Michigan from nearshore populations and from an offshore population on Sheboygan Reef, which is located in midlake. Gill nets and bottom trawls were used to catch lake trout in fall 1994 and 1995 from two nearshore sites and Sheboygan Reef. Each lake trout was judged immature or mature, based on visual examination of gonads. Probit analysis, coupled with relative potency testing, revealed that age-at-maturity and length-at-maturity were similar at the two nearshore sites, but that lake trout from the nearshore sites matured at a significantly earlier age than lake trout from Sheboygan Reef. However, length at maturity for the nearshore populations was nearly identical to that for the offshore population, suggesting that rate of lake trout maturation in Lake Michigan was governed by growth rather than age. Half of the lake trout males reached maturity at a total length of 580 mm, whereas half of the females were mature at a length of 640 mm. Over half of nearshore males were mature by age 5, and over half the nearshore females matured by age 6. Due to a slower growth rate, maturity was delayed by 2 years on Sheboygan Reef compared with the nearshore populations. Documentation of this delay in maturation may be useful in deciding stocking allocations for lake trout rehabilitation in Lake Michigan.

  3. Gas exchange on Mono Lake and Crowley Lake, California

    NASA Technical Reports Server (NTRS)

    Wanninkhof, Rik; Ledwell, James R.; Broecker, Wallace S.

    1987-01-01

    Gas exchange coefficients (k) have been determined for freshwater Crowley Lake and saline Mono Lake through the use of a man-made purposefully injected gas, SF6. The concentration decreased from an initial value of 40 to 4 pmol/L for Mono Lake and from 20 to 1 pmol/L for Crowley lake over a period of 6 wks. Wind-speed (u) records from anemometers on the shore of each lake made it possible to determine the relationship between k and u. The average u and k values for the experiment were identical for the two lakes, despite the large chemical differences. It is estimated that, for the u values observed over Mono Lake from July to December 1984, the exchange of CO2 occurred 2.5 times faster than without chemical enhancement. This is a factor of 4 lower than needed to explain the high invasion rate of C-14 produced by nuclear bomb tests.

  4. Lake whitefish diet, condition, and energy density in Lake Champlain and the lower four Great Lakes following dreissenid invasions

    USGS Publications Warehouse

    Herbst, Seth J.; Marsden, J. Ellen; Lantry, Brian F.

    2013-01-01

    Lake Whitefish Coregonus clupeaformis support some of the most valuable commercial freshwater fisheries in North America. Recent growth and condition decreases in Lake Whitefish populations in the Great Lakes have been attributed to the invasion of the dreissenid mussels, zebra mussels Dreissena polymorpha and quagga mussels D. bugensis, and the subsequent collapse of the amphipod, Diporeia, a once-abundant high energy prey source. Since 1993, Lake Champlain has also experienced the invasion and proliferation of zebra mussels, but in contrast to the Great Lakes, Diporeia were not historically abundant. We compared the diet, condition, and energy density of Lake Whitefish from Lake Champlain after the dreissenid mussel invasion to values for those of Lake Whitefish from Lakes Michigan, Huron, Erie, and Ontario. Lake Whitefish were collected using gill nets and bottom trawls, and their diets were quantified seasonally. Condition was estimated using Fulton's condition factor (K) and by determining energy density. In contrast to Lake Whitefish from some of the Great Lakes, those from Lake Champlain Lake Whitefish did not show a dietary shift towards dreissenid mussels, but instead fed primarily on fish eggs in spring, Mysis diluviana in summer, and gastropods and sphaeriids in fall and winter. Along with these dietary differences, the condition and energy density of Lake Whitefish from Lake Champlain were high compared with those of Lake Whitefish from Lakes Michigan, Huron, and Ontario after the dreissenid invasion, and were similar to Lake Whitefish from Lake Erie; fish from Lakes Michigan, Huron, and Ontario consumed dreissenids, whereas fish from Lake Erie did not. Our comparisons of Lake Whitefish populations in Lake Champlain to those in the Great Lakes indicate that diet and condition of Lake Champlain Lake Whitefish were not negatively affected by the dreissenid mussel invasion.

  5. Temperature Trends in Montane Lakes

    NASA Astrophysics Data System (ADS)

    Melack, J. M.; Sadro, S.; Jellison, R.

    2014-12-01

    Long-term temperature trends in lakes integrate hydrological and meteorological factors. We examine temperature trends in a small montane lake with prolonged ice-cover and large seasonal snowfall and in a large saline lake. Emerald Lake, located in the Sierra Nevada (California), is representative of high-elevation lakes throughout the region. No significant trend in outflow temperature was apparent from 1991to 2012. Snowfall in the watershed accounted for 93% of the variability in average summer lake temperatures. Mono Lake (California) lies in a closed, montane basin and is hypersaline and monomictic or meromictic. Temperature profiles have been collected from 1982 to 2010. In the upper water column, the July-August-September water temperatures increased 0.8-1.0°C over the 29 years. This rate of warming is less than published estimates based on satellite-derived skin temperatures and will discussed in the context of general limnological interpretation of temperature trends.

  6. Institutional aspects of lake management

    NASA Astrophysics Data System (ADS)

    Born, Stephen M.; Rumery, Carolyn

    1989-01-01

    The major barriers to successful lake management are institutional. However, in contrast to the technical and limnological dimensions of lake management, the institutional aspects of managing lakes have received little attention. The institutional factors that are important for successful lake management outcomes are: overlapping areal jurisdiction among governmental units, fragmented functional program responsibilities, ineffective coordination, limited authority, financial constraints, private sector roles, and inadequate public awareness and consensus. The range of typical institutional problems confronting lake management are well illustrated through experiences from the state of Wisconsin, USA. Because lake management programs with institutional shortcomings rarely realize their goals, it is critical to assimilate, evaluate, and apply our experience to date with the institutional arrangements necessary to effectively manage lake resources.

  7. CONTOURITES IN LAKE SUPERIOR

    EPA Science Inventory

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

  8. Utah: Salt Lake City

    Atmospheric Science Data Center

    2014-05-15

    ... mountains surrounding Salt Lake City are renowned for the dry, powdery snow that results from the arid climate and location at the ... should be used with the red filter placed over your left eye. The canyons and peaks of the Uinta and Wasatch Mountains are ...

  9. Quebec: Lake Manicouagan

    Atmospheric Science Data Center

    2013-04-17

    ... and other erosional processes have reduced the extent of the crater, with the original diameter estimated at about 100 kilometers. This ... metamorphic effects are abundant in the target rocks of the crater floor. Today Lake Manicouagan serves as a reservoir and is one of ...

  10. The People's Lake

    ERIC Educational Resources Information Center

    Carlson, Karen Townsend

    1975-01-01

    Citizen action to stop the disposal of taconite tailings into Lake Superior was unsuccessful when the courts settled in the favor of industry. Although citizen research revealed a form of asbestos, as well as other toxic chemicals in the discharged wastes, company representatives stated that there were no health hazards. (MA)

  11. Great Minds? Great Lakes!

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Chicago, IL. Great Lakes National Program Office.

    This booklet introduces an environmental curriculum for use in a variety of elementary subjects. The lesson plans provide an integrated approach to incorporating Great Lakes environmental issues into the subjects of history, social studies, and environmental sciences. Each of these sections contains background information, discussion points, and a…

  12. Echoes of Bark Lake.

    ERIC Educational Resources Information Center

    Duenkel, Nicky; Hemstreet, Jeff

    1997-01-01

    Two former staff members reflect on their feelings about the August 1995 closing of Bark Lake Leadership Centre (Ontario, Canada), which for 49 years had offered outdoor adventure and environmental education courses to youth and adults. They discuss their experiences as both students and teachers at the center, which helped shape their careers in…

  13. LAKE TAHOE VISIBILITY STUDY

    EPA Science Inventory

    Visibility monitoring and airborne particulate sampling in the Lake Tahoe Basin were used to document visual air quality levels and to assess the relative impacts of major contributing emission source categories. Visibility data were obtained by long path contrast and particle sc...

  14. Lake Ontario: Nearshore Variability

    EPA Science Inventory

    We conducted a high-resolution survey with towed electronic instrumentation along the Lake Ontario nearshore (720 km) at a 20 meter contour. The survey was conducted September 6-10, 2008 with a shorter 300 km survey conducted August 14-15 for comparing of temporal variability. ...

  15. Lake Michigan: Nearshore Variability

    EPA Science Inventory

    We conducted a high-resolution survey in the nearshore of Lake Michigan at a 20 meter contour using towed electronic instrumentation. The nearly 1200 km survey was conducted Sep 8-15, 2010. We also conducted six cross-contour tows. Along the survey tracks we sampled fixed stat...

  16. Lake level variability in Silver Lake, Michigan: a response to fluctuations in lake levels of Lake Michigan

    USGS Publications Warehouse

    Fisher, Timothy G.; Loope, Walter L.

    2004-01-01

    Sediment from Silver Lake, Michigan, can be used to constrain the timing and elevation of Lake Michigan during the Nipissing transgression. Silver Lake is separated from Lake Michigan by a barrier/dune complex and the Nipissing, Calumet, and Glenwood shorelines of Lake Michigan are expressed landward of this barrier. Two Vibracores were taken from the lake in February 2000 and contain pebbly sand, sand, buried soils, marl, peat, and sandy muck. It is suggested here that fluctuations in the level of Lake Michigan are reflected in Silver Lake since the Chippewa low phase, and possibly at the end of the Algonquin phase. An age of 12,490 B.P. (10,460±50 14C yrs B.P.) on wood from a buried Entisol may record the falling Algonquin phase as the North Bay outlet opened. A local perched water table is indicated by marl deposited before 7,800 B.P. and peat between 7,760-7,000 B.P. when Lake Michigan was at the low elevation Chippewa phase. Continued deepening of the lake is recorded by the transition from peat to sandy muck at 7,000 B.P. in the deeper core, and with the drowning of an Inceptisol nearly 3 m higher at 6,410 B.P. in the shallower core. A rising groundwater table responding to a rising Lake Michigan base level during the Nipissing transgression, rather than a response to mid-Holocene climate change, explains deepening of Silver Lake. Sandy muck was deposited continually in Silver Lake between Nipissing and modern time. Sand lenses within the muck are presumed to be eolian in origin, derived from sand dunes advancing into the lake on the western side of the basin.

  17. Temperate Lakes Discovered on Titan

    NASA Astrophysics Data System (ADS)

    Vixie, Graham; Barnes, Jason W.; Jackson, Brian; Wilson, Paul

    2012-04-01

    We have discovered two temperate lakes on Titan using Cassini's Visual and Infrared Mapping Spectrometer (VIMS). Three key features help to identify these surface features as lakes: morphology, albedo, and specular reflection. The presence of lakes at the mid-latitudes mean liquid can accumulate and remain stable outside of the poles. We first identify a lake surface by looking for possible shorelines with a lacustrine morphology. Then, we apply a simple atmospheric correction that produces an approximate surface albedo. Next, we prepare cylindrical projection maps of the brightness of the sky as seen from any points on the surface to identify specular reflections. Our techniques can then be applied to other areas, such as Arrakis Planitia, to test for liquid. Currently, all the known lakes on Titan are concentrated at the poles. Lakes have been suggested in the tropic zone by Griffith et al. Our discovery of non-transient, temperate lakes has important implications for Titan's hydrologic cycle. Clouds have been recorded accumulating in the mid-latitudes and areas have been darkened by rainfall but later brightened after evaporation (Turtle et al. 2011). Stable temperate lakes would affect total rainfall, liquid accumulation, evaporation rates, and infiltration. Polaznik Macula (Figure 1) is a great candidate for lake filling, evaporation rates, and stability. References: Griffith, C., et al.: "Evidence for Lakes on Titan's Tropical Surface". AAS/Division for Planetary Sciences Meeting Abstracts #42, Vol. 42, pp. 1077, 2010. Turtle, E. P., et al.: "Rapid and Extensive Surface Changes Near Titan's Equator: Evidence of April Showers". Science, Vol. 331, pp. 1414-, 2011. Figure 1: Polaznik Macula is the large, dark area central to the figure. The encircled dark blue areas represent positively identified lake regions in the T66 flyby. The light blue areas represent lake candidates still under analysis. The green circle marks a non-lake surface feature enclosed by a

  18. Microbiology of Lonar Lake and other soda lakes

    PubMed Central

    Paul Antony, Chakkiath; Kumaresan, Deepak; Hunger, Sindy; Drake, Harold L; Murrell, J Colin; Shouche, Yogesh S

    2013-01-01

    Soda lakes are saline and alkaline ecosystems that are believed to have existed throughout the geological record of Earth. They are widely distributed across the globe, but are highly abundant in terrestrial biomes such as deserts and steppes and in geologically interesting regions such as the East African Rift valley. The unusual geochemistry of these lakes supports the growth of an impressive array of microorganisms that are of ecological and economic importance. Haloalkaliphilic Bacteria and Archaea belonging to all major trophic groups have been described from many soda lakes, including lakes with exceptionally high levels of heavy metals. Lonar Lake is a soda lake that is centered at an unusual meteorite impact structure in the Deccan basalts in India and its key physicochemical and microbiological characteristics are highlighted in this article. The occurrence of diverse functional groups of microbes, such as methanogens, methanotrophs, phototrophs, denitrifiers, sulfur oxidizers, sulfate reducers and syntrophs in soda lakes, suggests that these habitats harbor complex microbial food webs that (a) interconnect various biological cycles via redox coupling and (b) impact on the production and consumption of greenhouse gases. Soda lake microorganisms harbor several biotechnologically relevant enzymes and biomolecules (for example, cellulases, amylases, ectoine) and there is the need to augment bioprospecting efforts in soda lake environments with new integrated approaches. Importantly, some saline and alkaline lake ecosystems around the world need to be protected from anthropogenic pressures that threaten their long-term existence. PMID:23178675

  19. Lake trout rehabilitation in Lake Erie: a case history

    USGS Publications Warehouse

    Cornelius, Floyd C.; Muth, Kenneth M.; Kenyon, Roger

    1995-01-01

    Native lake trout (Salvelinus namaycush) once thrived in the deep waters of eastern Lake Erie. The impact of nearly 70 years of unregulated exploitation and over 100 years of progressively severe cultural eutrophication resulted in the elimination of lake trout stocks by 1950. Early attempts to restore lake trout by stocking were unsuccessful in establishing a self-sustaining population. In the early 1980s, New York's Department of Environmental Conservation, Pennsylvania's Fish and Boat Commission, and the U.S. Fish and Wildlife Service entered into a cooperative program to rehabilitate lake trout in the eastern basin of Lake Erie. After 11 years of stocking selected strains of lake trout in U.S. waters, followed by effective sea lamprey control, lake trout appear to be successfully recolonizing their native habitat. Adult stocks have built up significantly and are expanding their range in the lake. Preliminary investigations suggest that lake trout reproductive habitat is still adequate for natural reproduction, but natural recruitment has not been documented. Future assessments will be directed toward evaluation of spawning success and tracking age-class cohorts as they move through the fishery.

  20. 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

  1. Predicting Maximum Lake Depth from Surrounding Topography

    EPA Science Inventory

    Lake volume aids understanding of the physical and ecological dynamics of lakes, yet is often not readily available. The data needed to calculate lake volume (i.e. bathymetry) are usually only collected on a lake by lake basis and are difficult to obtain across broad regions. ...

  2. Lake Mead--clear and vital

    USGS Publications Warehouse

    Wessells, Stephen M.; Rosen, Michael

    2013-01-01

    Lake Mead – Clear and Vital” is a 13 minute documentary relating the crucial role of science in maintaining high water quality in Lake Mead. The program was produced coincident with release of the Lakes Mead and Mohave Circular a USGS publication covering past and on-going research in the lakes and tributaries of the Lake Mead National Recreation Area.

  3. Lake Erie...Take a Bow.

    ERIC Educational Resources Information Center

    Canning, Maureen; Dunlevy, Margie

    This elementary school teaching unit was developed as a part of a series of teaching units that deal with Lake Erie. This unit was developed to enable children to: (1) identify the Great Lakes and pick out Lake Erie on a map; (2) demonstrate knowledge of Lake Erie's origin and geography; (3) list some uses of Lake Erie; and (4) give examples of…

  4. Fecundity of hatchery lake trout in Lake Ontario

    USGS Publications Warehouse

    Fitzsimons, John D.; O'Gorman, Robert

    1996-01-01

    Fecundity (egg number) was determined from 26 stocked (617-800 mm, total length) lake trout (Salvelinus namaycush) collected in western Lake Ontario during September 1992. Previous to this study, fecundity was evaluated only once in Lake Ontario using native stocks in 1927. The following relationships between fecundity and total length (TL) and weight (W) were obtained. Fecundity = -12,492 + 25.87 TL(mm) and Fecundity = -1,010 + 1,307 W(kg). Relative fecundity (number of eggs per kg of body weight) was unrelated to body weight and averaged 1,592 eggs kg-1. Fecundity of contemporary lake trout based on length was significantly lower than that of historic native stocks, but was similar to contemporary stocked lake trout in Lake Superior.

  5. Lake Garda, Italy

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

    The image is centered at 45.6 degrees north latitude, 10.6 degrees east longitude.

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, Calif., is the U.S. Science team leader; Moshe Pniel of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The primary goal of the ASTER mission is to obtain high-resolution image data in 14 channels over the entire land surface, as well as black and white stereo images. With revisit time of between 4 and 16 days, ASTER will provide the capability for repeat coverage of changing areas on Earth's surface.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for

  6. 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.

  7. Genetic diversity of Diporeia in the Great Lakes: comparison of Lake Superior to the other Great Lakes

    EPA Science Inventory

    Abundances of Diporeia have dropped drastically in the Great Lakes, except in Lake Superior, where data suggest that population counts actually have risen. Various ecological, environmental, or geographic hypotheses have been proposed to explain the greater abundance of Lake Supe...

  8. Aeolian sand preserved in Silver Lake: a new signal of Holocene high stands of Lake Michigan

    USGS Publications Warehouse

    Fisher, Timothy G.; Loope, Walter L.

    2005-01-01

    Aeolian sand within lake sediment from Silver Lake, Michigan can be used as a proxy for the timing of high lake levels of Lake Michigan.We demonstrate that the sand record from Silver Lake plotted as percent weight is in-phase with the elevation curve of Lake Michigan since the mid-Holocene Nipissing Phase. Because fluctuations in Lake Michigan's lake level are recorded in beach ridges, and are a response to climate change, the aeolian sand record within Silver Lake is also a proxy for climate change. It appears that increases in dune activity and lake sand are controlled by similar climatic shifts that drive fluctuations in lake level of Lake Michigan. High lake levels destabilize coastal bluffs that drive dune sand instability, and along with greater wintertime storminess, increase niveo-aeolian transport of sand across lake ice. The sand is introduced into the lake each spring as the ice cover melts.

  9. Life history of lake herring in Lake Superior

    USGS Publications Warehouse

    Dryer, William R.; Beil, Joseph

    1964-01-01

    The average annual commercial catch of lake herring (Coregonus artedi) in U.S. waters of Lake Superior was nearly 12 million pounds in 1929-61. This production contributed 62.4 percent of the total U.S. take of lake herring for the Great Lakes. About 90 percent of the annual catch is taken from small-mesh gill nets during the November-December spawning season. The life-history studies were based on 12,187 fish collected in 1950-62; past growth was computed for 3,779 specimens collected from commercial landings at: Duluth, Minn.; Bayfield, Wis.; and Portage Entry and Marquette, Mich.

  10. Carbon fluxes and the carbon budget in agroecosystems on agro-gray soils of the forest-steppe in the Baikal region

    NASA Astrophysics Data System (ADS)

    Pomazkina, L. V.; Sokolova, L. G.; Zvyagintseva, E. N.

    2013-06-01

    Field studies devoted to the transformation of the carbon cycle in agroecosystems on agro-gray soils (including soils contaminated with fluorides from aluminum smelters) in dependence on the changes in the hydrothermic conditions were performed for the first time within the framework of the long-term (1996-2010) soil monitoring in the forest-steppe zone of the Baikal region. The major attention was paid to the impact of the environmental factors on the synthesis and microbial destruction of organic carbon compounds. Certain differences in the fluxes and budget of carbon were found for the plots with cereal and row crops and for the permanent and annual fallow plots. The adverse effect of fluorides manifested itself in the enhanced C-CO2 emission under unfavorable water and temperature conditions. The long-term average C-CO2 emission from the soils contaminated with fluorides in agroecosystems with wheat after fallow was higher than that from the uncontaminated soil (179 and 198 g of C/m2, respectively) and higher than that in the agroecosystems with a potato monoculture (129 and 141 g of C/m2, respectively). At the same time, no significant variations in the content of the carbon of the microbial biomass (Cmicr) in dependence on the environmental factors were found. The utilization of carbon for respiration and for growth of the soil microorganisms on the contaminated soil were unbalanced in particular years and for the entire period of the observations. The ratio between the fluxes of the net mineralized and re-immobilized carbon was used for the integral assessment of the functioning regime of the agroecosystems and the loads on them. Independently from the soil contamination with fluorides, the loads on the agroecosystems with wheat were close to the maximum permissible value, and the loads on the agroecosystems with potatoes were permissible. It was shown that the carbon deficit in the uncontaminated soils was similar under the wheat and potatoes (-30 and -28 g

  11. Effects of interaction between ultramafic tectonite and mafic magma on Nd-Pb-Sr isotopic systems in the Neoproterozoic Chaya Massif, Baikal-Muya ophiolite belt

    USGS Publications Warehouse

    Amelin, Y.V.; Ritsk, E. Yu; Neymark, L.A.

    1997-01-01

    Sm-Nd, Rb-Sr and U-Pb isotopic systems have been studied in minerals and whole rocks of harzburgites and mafic cumulates from the Chaya Massif, Baikal-Muya ophiolite belt, eastern Siberia, in order to determine the relationship between mantle ultramafic and crustal mafic sections. Geological relations in the Chaya Massif indicate that the mafic magmas were emplaced into, and interacted with older solid peridotite. Hand picked, acid-leached, primary rock-forming and accessory minerals (olivine, orthopyroxene, clinopyroxene and plagioclase) from the two harzburgite samples show coherent behavior and yield 147Sm/144Nd- 143Nd/144Nd and 238U/204Pb-206Pb/204Pb mineral isochrons, corresponding to ages of 640 ?? 58 Ma (95% confidence level) and 620 ?? 71 Ma, respectively. These values are indistinguishable from the crystallization age of the Chaya mafic units of 627 ?? 25 Ma (a weighted average of internal isochron Sm-Nd ages of four mafic cumulates). The Rb-Sr and Sm-Nd isotopic systems in the harzburgite whole-rock samples were disturbed by hydrothermal alteration. These alteration-related isotopic shifts mimic the trend of variations in primary isotopic compositions in the mafic sequence, thus emphasizing that isotopic data for ultramafic rocks should be interpreted with great caution. On the basis of initial Sr and Nd values, ultramafic and mafic rocks of the Chaya Massif can be divided into two groups: (1) harzburgites and the lower mafic unit gabbronorites with ??Nd = +6.6 to +7.1 and ??Sr = -11 to -16; and (2) websterite of the lower unit and gabbronorites of the upper mafic unit: ??Nd = + 4.6 to + 6.1 and ??Sr = - 8 to -9. Initial Pb isotopic ratios are identical in all rocks studied, with mean values of 206Pb/204Pb = 16.994 ?? 0.023 and 207Pb/204Pb = 15.363 ?? 0.015. The similarity of ages and initial isotopic ratios within the first group indicates that the isotopic systems in the pre-existing depleted peridotite were reset by extensive interaction with basaltic

  12. Hydrology of Lake County, Florida

    USGS Publications Warehouse

    Knochenmus, Darwin D.; Hughes, G.H.

    1976-01-01

    Lake County includes a 1,150 square-mile area consisting of ridges, uplands, and valleys in central-peninsular Florida. About 32 percent of the county is covered by lakes, swamps, and marshes. Water requirements in 1970 averaged about 54 million gallons per day. About 85 percent of the water was obtained from wells; about 15 percent from lakes. The Floridan aquifer supplies almost all the ground water used in Lake County. Annual recharge to the Floridan aquifer averages about 7 inches over the county; runoff average 8.5 inches. The quality of ground and surface water in Lake County is in general good enough for most uses; however, the poor quality of Floridan-aquifer water in the St. John River Valley probably results from the upward movement of saline water along a fault zone. Surface water in Lake County is usually less mineralized than ground water but is more turbid and colored. (Woodard-USGS)

  13. Not so Great Lakes?

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    In 1965, Frank Sinatra won the Grammy Award for his album, "September of My Years;" "Early Bird," the first commercial communications satellite, was launched; and Dr. Martin Luther King, Jr. was arrested in Selma, Alabama, during demonstrations against voter-registration rules.The year 1965 was also the last time water levels in the U.S. Great Lakes were as low as they are now.

  14. Not so Great Lakes?

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    In 1965, Frank Sinatra won the Grammy Award for his album, “September of My Years” “Early Bird,” the first commercial communications satellite, was launched; and Dr. Martin Luther King, Jr. was arrested in Selma, Alabama, during demonstrations against voter-registration rules.The year 1965 was also the last time water levels in the U.S. Great Lakes were as low as they are now.

  15. Archaea in Yellowstone Lake

    PubMed Central

    Kan, Jinjun; Clingenpeel, Scott; Macur, Richard E; Inskeep, William P; Lovalvo, Dave; Varley, John; Gorby, Yuri; McDermott, Timothy R; Nealson, Kenneth

    2011-01-01

    The Yellowstone geothermal complex has yielded foundational discoveries that have significantly enhanced our understanding of the Archaea. This study continues on this theme, examining Yellowstone Lake and its lake floor hydrothermal vents. Significant Archaea novelty and diversity were found associated with two near-surface photic zone environments and two vents that varied in their depth, temperature and geochemical profile. Phylogenetic diversity was assessed using 454-FLX sequencing (∼51 000 pyrosequencing reads; V1 and V2 regions) and Sanger sequencing of 200 near-full-length polymerase chain reaction (PCR) clones. Automated classifiers (Ribosomal Database Project (RDP) and Greengenes) were problematic for the 454-FLX reads (wrong domain or phylum), although BLAST analysis of the 454-FLX reads against the phylogenetically placed full-length Sanger sequenced PCR clones proved reliable. Most of the archaeal diversity was associated with vents, and as expected there were differences between the vents and the near-surface photic zone samples. Thaumarchaeota dominated all samples: vent-associated organisms corresponded to the largely uncharacterized Marine Group I, and in surface waters, ∼69–84% of the 454-FLX reads matched archaeal clones representing organisms that are Nitrosopumilus maritimus-like (96–97% identity). Importance of the lake nitrogen cycling was also suggested by >5% of the alkaline vent phylotypes being closely related to the nitrifier Candidatus Nitrosocaldus yellowstonii. The Euryarchaeota were primarily related to the uncharacterized environmental clones that make up the Deep Sea Euryarchaeal Group or Deep Sea Hydrothermal Vent Group-6. The phylogenetic parallels of Yellowstone Lake archaea to marine microorganisms provide opportunities to examine interesting evolutionary tracks between freshwater and marine lineages. PMID:21544103

  16. Great Lakes Energy Institute

    SciTech Connect

    Alexander, J. Iwan

    2012-11-18

    The vision of the Great Lakes Energy Institute is to enable the transition to advanced, sustainable energy generation, storage, distribution and utilization through coordinated research, development, and education. The Institute will place emphasis on translating leading edge research into next generation energy technology. The Institute’s research thrusts focus on coordinated research in decentralized power generation devices (e.g. fuel cells, wind turbines, solar photovoltaic devices), management of electrical power transmission and distribution, energy storage, and energy efficiency.

  17. Angora Fire, Lake Tahoe

    NASA Technical Reports Server (NTRS)

    2007-01-01

    On the weekend of June 23, 2007, a wildfire broke out south of Lake Tahoe, which stretches across the California-Nevada border. By June 28, the Angora Fire had burned more than 200 homes and forced some 2,000 residents to evacuate, according to The Seattle Times and the Central Valley Business Times. On June 27, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of the burn scar left by the Angora fire. The burn scar is dark gray, or charcoal. Water bodies, including the southern tip of Lake Tahoe and Fallen Leaf Lake, are pale silvery blue, the silver color a result of sunlight reflecting off the surface of the water. Vegetation ranges in color from dark to bright green. Streets are light gray, and the customary pattern of meandering residential streets and cul-de-sacs appears throughout the image, including the area that burned. The burn scar shows where the fire obliterated some of the residential areas just east of Fallen Leaf Lake. According to news reports, the U.S. Forest Service had expressed optimism about containing the fire within a week of the outbreak, but a few days after the fire started, it jumped a defense, forcing the evacuation of hundreds more residents. Strong winds that had been forecast for June 27, however, did not materialize, allowing firefighters to regain ground in controlling the blaze. On June 27, authorities hoped that the fire would be completely contained by July 3. According to estimates provided in the daily report from the National Interagency Fire Center, the fire had burned 3,100 acres (about 12.5 square kilometers) and was about 55 percent contained as of June 28. Some mandatory evacuations remained in effect. NASA image by Jesse Allen, using data provided courtesy of the NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

  18. Method for lake restoration

    DOEpatents

    Dawson, Gaynor W.; Mercer, Basil W.

    1979-01-01

    A process for removing pollutants or minerals from lake, river or ocean sediments or from mine tailings is disclosed. Magnetically attractable collection units containing an ion exchange or sorbent media with an affinity for a chosen target substance are distributed in the sediments or tailings. After a period of time has passed sufficient for the particles to bind up the target substances, a magnet drawn through the sediments or across the tailings retrieves the units along with the target substance.

  19. 27 CFR 9.184 - Trinity Lakes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... Provisional Edition 1982. (c) Boundary. The Trinity Lakes viticultural area is located in Trinity County in northern California. The boundary encompasses Trinity Lake and Lewiston Lake, both within the Trinity...

  20. 27 CFR 9.184 - Trinity Lakes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... Provisional Edition 1982. (c) Boundary. The Trinity Lakes viticultural area is located in Trinity County in northern California. The boundary encompasses Trinity Lake and Lewiston Lake, both within the Trinity...

  1. 27 CFR 9.184 - Trinity Lakes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... Provisional Edition 1982. (c) Boundary. The Trinity Lakes viticultural area is located in Trinity County in northern California. The boundary encompasses Trinity Lake and Lewiston Lake, both within the Trinity...

  2. 27 CFR 9.184 - Trinity Lakes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... Provisional Edition 1982. (c) Boundary. The Trinity Lakes viticultural area is located in Trinity County in northern California. The boundary encompasses Trinity Lake and Lewiston Lake, both within the Trinity...

  3. 27 CFR 9.184 - Trinity Lakes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... Provisional Edition 1982. (c) Boundary. The Trinity Lakes viticultural area is located in Trinity County in northern California. The boundary encompasses Trinity Lake and Lewiston Lake, both within the Trinity...

  4. Landsat analysis of lake quality

    NASA Technical Reports Server (NTRS)

    Scarpace, F. L.; Fisher, L. T.; Holmquist, K. W.

    1979-01-01

    The trophic status of a number of inland lakes in Wisconsin has been assessed. The feasibility of using both photographic and digital representations of Landsat imagery was investigated during the lake classification project. The result of the investigation has been a semi-automatic data acquisition and handling system which, in conjunction with an analytical categorization scheme, can be used to classify all the significant lakes in the state.

  5. Crater Lake: blue through time

    USGS Publications Warehouse

    Larson, Gary L.; Buktenica, Mark; Collier, Robert

    2003-01-01

    Blue is the color of constancy, hence the term true blue. The unearthly blueness of Crater Lake reflects its pristine character and gives scientists a focal point for studying human impacts on aquatic environments over long periods of time. Scientists with the U.S. Geological Survey (USGS), National Park Service, and Oregon State University have systematically studied the lake for the last two decades. Long-term monitoring of this lake is a priority of Crater Lake National Park and will continue far into the future.

  6. Progress toward lake trout restoration in Lake Michigan

    USGS Publications Warehouse

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

    1995-01-01

    Progress toward lake trout restoration in Lake Michigan is described through 1993. Extinction of the native lake trout fishery by sea lamprey predation, augmented by exploitation and habitat destruction, resulted in an extensive stocking program of hatchery-reared lake trout that began in 1965. Sea lamprey abundance was effectively controlled using selective chemical toxicants. The initial stocking produced a measurable wild year class of lake trout by 1976 in Grand Traverse Bay, but failed to continue probably due to excessive exploitation. The overall lack of successful reproduction lakewide by the late 1970s led to the development and implementation in 1985 of a focused inter-agency lakewide restoration plan by a technical committee created through the Lake Committee structure of the Great Lakes Fishery Commission. Strategies implemented in 1985 by the plan included setting a 40% total mortality goal lakewide, creating two large refuges designed to encompass historically the most productive spawning habitat and protect trout stocked over their home range, evaluating several lake trout strains, and setting stocking priorities throughout the lake. Target levels for stocking in the 1985 Plan have never been reached, and are much less than the estimated lakewide recruitment of yearlings by the native lake trout stocks. Since 1985, over 90% of the available lake trout have been stocked over the best spawning habitat, and colonization of the historically productive offshore reefs has occurred. Concentrations of spawning lake trout large enough for successful reproduction, based on observations of successful hatchery and wild stocks, have developed at specific reefs. Continued lack of recruitment at these specific sites suggests that something other than stotk abundance has limited success. Poor survival of lake trout eggs, assumed to be related to contaminant burden, occurred in the late 1970s and early 1980s, but survival has since increased to equal survival in the

  7. Glacioisostasy and Lake-Level Change at Moosehead Lake, Maine

    USGS Publications Warehouse

    Balco, G.; Belknap, D.F.; Kelley, J.T.

    1998-01-01

    Reconstructions of glacioisostatic rebound based on relative sea level in Maine and adjacent Canada do not agree well with existing geophysical models. In order to understand these discrepancies better, we investigated the lake-level history of 40-km-long Moosehead Lake in northwestern Maine. Glacioisostasy has affected the level of Moosehead Lake since deglaciation ca. 12,500 14C yr B.P. Lowstand features at the southeastern end and an abandoned outlet at the northwestern end of the lake indicate that the lake basin was tilted down to the northwest, toward the retreating ice sheet, by 0.7 m/km at 10,000 14C yr B.P. Water level then rose rapidly in the southeastern end of the lake, and the northwestern outlet was abandoned, indicating rapid relaxation of landscape tilt. Lowstand features at the northwestern end of the lake suggest that the lake basin was tilted to the southeast at ca. 8750 14C yr B.P., possibly as the result of a migrating isostatic forebulge. After 8000 14C yr B.P., water level at the southeastern end was again below present lake level and rose gradually thereafter. We found no evidence suggesting that postglacial climate change significantly affected lake level. The rebound history inferred from lake-level data is consistent with previous interpretations of nearby relative sealevel data, which indicate a significantly steeper and faster-moving ice-proximal depression and ice-distal forebulge than geophysical models predict. ?? 1998 University of Washington.

  8. Lake Charles CCS Project

    SciTech Connect

    Leib, Thomas; Cole, Dan

    2015-06-30

    In late September 2014 development of the Lake Charles Clean Energy (LCCE) Plant was abandoned resulting in termination of Lake Charles Carbon Capture and Sequestration (CCS) Project which was a subset the LCCE Plant. As a result, the project was only funded through Phase 2A (Design) and did not enter Phase 2B (Construction) or Phase 2C (Operations). This report was prepared relying on information prepared and provided by engineering companies which were engaged by Leucadia Energy, LLC to prepare or review Front End Engineering and Design (FEED) for the Lake Charles Clean Energy Project, which includes the Carbon Capture and Sequestration (CCS) Project in Lake Charles, Louisiana. The Lake Charles Carbon Capture and Sequestration (CCS) Project was to be a large-scale industrial CCS project intended to demonstrate advanced technologies that capture and sequester carbon dioxide (CO2) emissions from industrial sources into underground formations. The Scope of work was divided into two discrete sections; 1) Capture and Compression prepared by the Recipient Leucadia Energy, LLC, and 2) Transport and Sequestration prepared by sub-Recipient Denbury Onshore, LLC. Capture and Compression-The Lake Charles CCS Project Final Technical Report describes the systems and equipment that would be necessary to capture CO2 generated in a large industrial gasification process and sequester the CO2 into underground formations. The purpose of each system is defined along with a description of its equipment and operation. Criteria for selection of major equipment are provided and ancillary utilities necessary for safe and reliable operation in compliance with environmental regulations are described. Construction considerations are described including a general arrangement of the CCS process units within the overall gasification project. A cost estimate is provided, delineated by system area with cost breakdown showing equipment, piping and materials

  9. Grand Canyon, Lake Powell, and Lake Mead

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A snowfall in the American West provides contrast to the landscape's muted earth tones and indicates changes in topography and elevation across (clockwise from top left) Nevada, Utah, Colorado, New Mexico, Arizona, and California. In Utah, the southern ranges of the Wasatch Mountains are covered in snow, and the Colorado River etches a dark ribbon across the red rock of the Colorado Plateau. In the center of the image is the reservoir created by the Glen Canyon Dam. To the east are the gray-colored slopes of Navaho Mountain, and to the southeast, dusted with snow is the region called Black Mesa. Southwest of Glen Canyon, the Colorado enters the Grand Canyon, which cuts westward through Arizona. At a deep bend in the river, the higher elevations of the Keibab Plateau have held onto snow. At the end of the Grand Canyon lies another large reservoir, Lake Mead, which is formed by the Hoover Dam. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  10. Holocene lake-level fluctuations of Lake Aricota, Southern Peru

    USGS Publications Warehouse

    Placzek, C.; Quade, Jay; Betancourt, J.L.

    2001-01-01

    Lacustrine deposits exposed around Lake Aricota, Peru (17?? 22???S), a 7.5-km2 lake dammed by debris flows, provide a middle to late Holocene record of lake-level fluctuations. Chronological context for shoreline deposits was obtained from radiocarbon dating of vascular plant remains and other datable material with minimal 14C reservoir effects (<350 yr). Diatomites associated with highstands several meters above the modern lake level indicate wet episodes. Maximum Holocene lake level was attained before 6100 14C yr B.P. and ended ???2700 14C yr B.P. Moderately high lake levels occurred at 1700 and 1300 14C yr B.P. The highstand at Lake Aricota during the middle Holocene is coeval with a major lowstand at Lake Titicaca (16?? S), which is only 130 km to the northeast and shares a similar climatology. Comparisons with other marine and terrestrial records highlight emerging contradictions over the nature of mid-Holocene climate in the central Andes. ?? 2001 University of Washington.

  11. The near extinction of lake trout in Lake Michigan

    USGS Publications Warehouse

    Eschmeyer, Paul H.

    1957-01-01

    Comparisons in 1949 and 1950 of numbers of legal-sized lake trout caught in large-mesh nets with numbers of small fish taken in chub nets showed that both large and small lake trout declined over the same period, and that by these years the decline may have been greater among small than among legal-sized fish.

  12. ARE LAKES GETTING WARMER? REMOTE SENSING OF LARGE LAKE TEMPERATURES

    EPA Science Inventory

    Recent studies (Levitus et al., 2000) suggest a warning of the world ocean over the past 50 years. Freshwater lakes could also be getting warmer but thermal measurements to determine this are lacking. Large lake temperatures are vertically and horizontally heterogeneous and vary ...

  13. Geographical distributions of lake trout strains stocked in Lake Ontario

    USGS Publications Warehouse

    Elrod, Joseph H.; O'Gorman, Robert; Schneider, Clifford P.; Schaner, Ted

    1996-01-01

    Geographical distributions of lake trout (Salvelinus namaycush) stocked at seven locations in U.S. waters and at four locations in Canadian waters of Lake Ontario were determined from fish caught with gill nets in September in 17 areas of U.S. waters and at 10 fixed locations in Canadian waters in 1986-95. For fish of a given strain stocked at a given location, geographical distributions were not different for immature males and immature females or for mature males and mature females. The proportion of total catch at the three locations nearest the stocking location was higher for mature fish than for immature fish in all 24 available comparisons (sexes combined) and was greater for fish stocked as yearlings than for those stocked as fingerlings in all eight comparisons. Mature fish were relatively widely dispersed from stocking locations indicating that their tendency to return to stocking locations for spawning was weak, and there was no appreciable difference in this tendency among strains. Mature lake trout were uniformly distributed among sampling locations, and the strain composition at stocking locations generally reflected the stocking history 5 to 6 years earlier. Few lake trout moved across Lake Ontario between the north and south shores or between the eastern outlet basin and the main lake basin. Limited dispersal from stocking sites supports the concept of stocking different genetic strains in various parts of the lake with the attributes of each strain selected to match environmental conditions in the portion of the lake where it is stocked.

  14. Biology of young lake trout (Salvelinus namaycush) in Lake Michigan

    USGS Publications Warehouse

    Van Oosten, John; Eschmeyer, Paul H.

    1956-01-01

    Experimental fishing with gill nets of 5 mesh sizes (2 3/8 to 3 inches) in Lake Michigan in 1930-32 yielded more than 16,000 young lake trout. Data are presented here on age, growth, length-weight relationship, abundance, geographical and bathymetric distribution, and other details of their biology.

  15. The Lake Ohrid SCOPSCO project

    NASA Astrophysics Data System (ADS)

    Wagner, Bernd; Wilke, Thomas; Krastel, Sebastian; Zanchetta, Giovanni; Sulpizio, Roberto; Leng, Melanie J.; Francke, Alexander; Baumgarten, Henrike; Cvetkoska, Aleksandra; Giacco, Biagio; Lacey, Jack H.; Leicher, Niklas; Levkov, Zlatko; Lindhorst, Katja; Reed, Jane M.; Zhang, Xiaosen; Sadori, Laura; Vogel, Hendrik; Wagner-Cremer, Friederike; Wonik, Thomas

    2015-04-01

    The ICDP SCOPSCO project at Lake Ohrid in Macedonia and Albania was one of the most successful lake drilling campaigns worldwide. Drilling took place from April to June 2013 and yielded more than 2000 m of sediments from four different sites in the lake. The maximum penetration was 569 m below lake floor and the overall recovery at all drill sites was > 95 %. Almost two years after the drilling operation, core opening and processing as well as biological and geological analyses are still ongoing. However, most of the cores from the main drill site, the so-called DEEP site in the centre of the lake, are meanwhile opened and reveal a unique record of lake history. The extraordinary quality of seismic, borehole logging and core data allows us to achieve the major goals of the SCOPSCO project. Seismic data, diatoms and coarse-grained sediments in the basal cores indicate that Lake Ohrid had no marine origin, as it was speculated in the past. The data show that Lake Ohrid established in a highly dynamic pull-apart basin with varying fluvial and shallow water conditions. On top of these basal sediments, borehole logging data, XRF scanning data, carbonate, and the amount of organic matter indicate a complete and high resolution succession of glacial / interglacial cycles and interspersed stadials and interstadials. This allows us to determine the establishment of Lake Ohrid by means of chronostratigraphic tuning to about 1.3 to 1.5 Ma ago. Additional, independent age control is given by paleomagnetic data and by numerous tephra layers, which can be correlated with well-dated proximal tephra deposits in Italy. The uppermost 350 m of the sediment record contain more than 30 tephras, which makes the Lake Ohrid record to the rosetta stone of distal Italian tephra deposits in the Balkan region. The unique sediment record of Lake Ohrid is fundamental to obtain crucial information on the overall goal of the SCOPSCO project, i.e. to clarify why Lake Ohrid has one of highest

  16. Feeding competition between larval lake whitefish and lake herring

    USGS Publications Warehouse

    Savino, Jacqueline F.; Hudson, Patrick L.

    1995-01-01

    The potential for competition for food between larval lake whitefish (Coregonus clupeaformis) and lake herring (C. artedi) 1- to 8-wk of age was explored in a series of 1-h laboratory feeding studies. Feeding started at 2-wk post-hatch. Learning and fish size appear to be more important than prey density at the onset of feeding. Species differed in their feeding behavior and consumption noticeably by 5-wk and substantially by 8-wk. Lake whitefish generally were more aggressive foragers than lake herring, attacking and capturing more prey. At high plankton density at 8-wk, lake herring feeding was depressed in mixed-fish treatments. This difference in competitive food consumption between the two coregonids occurs at a critical life stage, and when combined with other biotic and abiotic factors, may have a significant impact on recruitment.

  17. Forecasting Lake-Effect Snow in the Great Lakes Using NASA Satllite Data

    NASA Technical Reports Server (NTRS)

    Cipullo, Michelle; Molthan, Andrew; Shafer, Jackie; Case, Jonathan; Jedlovec, Gary

    2011-01-01

    This slide presentation reviews the forecast of the lake effect snow in the Great Lakes region using models and infrared estimates of Great Lake Surface Temperatures (GLSTs) from the MModerate Resolution Imaging Spectroradiometer (MODIS) instrument on Terra and Aqua satellites, and other satellite data. This study analyzes Lake Erie and Lake Ontario which produce storm total snowfall ranged from 8-18 inches off of Lake Ontario and 10-12 inches off of Lake Erie for the areas downwind.

  18. The main features of the interaction of mantle magmas with granulite complexes of the lower crust and their relationship with granitic melts (exemplified by the Early Caledonides of the West Baikal Region, Russia)

    NASA Astrophysics Data System (ADS)

    Vladimirov, Alexandr; Khromykh, Sergei; Mekhonoshin, Alexei; Volkova, Nina; Travin, Alexei; Mikheev, Evgeny; Vladimirova, Anna

    2016-04-01

    Granulite complexes occurring in the Early Caledonian southern folded framing of the Siberian Craton are deeply eroded fragments of the Vendian-Early Paleozoic accretionary prism, which is an indicator of the early stages of the Paleo-Asian Ocean (Gladkochub et al., 2010). The main feature of the granulite complexes is a wide development of gabbro-pyroxenites composing tectonic plates, synmetamorphic intrusive bodies, and numerous disintegrated fragments (boudins and enclaves), immersed in a metamorphic matrix. The volume of basites reaches 5-10 %, which allows us to consider mantle magmatism as a heat source for the granulite metamorphism. The most studied polygon is Chernorud granulite zone, which is a part of the Olkhon metamorphic terrane, West Baikal Region. Just this polygon was used for considering the problems of interaction of mantle magmas with lower crust granulite complexes and their relationship with granitic melts. The Chernorud Zone is a typical example of the accretionary prism with a predominance of metabasalts (70-80 %), subordinate amounts of marbles, quartzites and metapelites that have been subjected to granulite facies metamorphism and viscoelastic flow of rock masses. Study of two-pyroxene granulites (metabasalts) and garnet-sillimanite gneisses (metapelites) allows us to estimate P-T metamorphic conditions (P = 7.7-8.6 kbar, T = 770-820°C) and their U-Pb metamorphic age (530-500 Ma). Metabasalts correspond in their geochemistry to the island-arc tholeiitic series (Volkova et al., 2010; Gladkochub et al., 2010). Sin-metamorphic gabbro-pyroxenites formed in two stages: 1) Chernorud complex - tectonic slices and body's exhumed from deep earth crust levels (10-12 kb) and composed of arc tholeiitic series rocks (age T ≥ 500 Ma); 2) Ulan-Khargana complex - supply magmatic canals and fragmented tabular intrusions. This rocks composition corresponds to subalkaline petrochemical series (OIB) and U/Pb age is equal to 485±10 Ma (Travin et al., 2009

  19. An urban lake remediation experiment

    SciTech Connect

    Castelli, S.E.; Gardner, K.H.; Jennings, A.A.

    1998-07-01

    Circumstances provided the opportunity to study a small urban lake as the surrounding municipalities attempted to improve its aesthetic quality by dredging. This manuscript focuses primarily on the sediments in the system: accumulation rates, the expected dynamics of the lake bed drying process, and the influence of the sediments on water quality.

  20. The Great Lakes Food Web.

    ERIC Educational Resources Information Center

    Baker, Marjane L.

    1997-01-01

    Presents a play for students in grades four to nine that incorporates the scientific names, physical characteristics, feeding habits, interactions, and interdependence of the plants and animals that make up the Great Lakes food web to facilitate the learning of this complex system. Includes a Great Lakes food web chart. (AIM)

  1. NATIONAL LAKE ASSESSMENT MONITORING DESIGN

    EPA Science Inventory

    The USEPA designed the National Lake Assessment in 2005-6 with field sampling being completed in 2007. The objective of the assessment is to estimate the ecological condition of lakes and reservoirs nationally. The objective of this paper is to describe the national survey desi...

  2. New England Lakes & Ponds Project

    EPA Science Inventory

    The New England Lakes and Ponds Project provides a consistent and first time comprehensive assessment of the ecological and water quality condition of lakes and ponds across the New England region. The project is being conducted by EPA along with the New England Interstate Water...

  3. PYRAMID LAKE RENEWEABLE ENERGY PLAN

    SciTech Connect

    HIGH DESERT GEOCULTURE, LLC

    2009-06-06

    The Pyramid Lake Renewable Energy Plan covers these areas: energy potential (primarily focusing on geothermal resource potential, but also more generally addressing wind energy potential); renewable energy market potential; transmission system development; geothermal direct use potential; and business structures to accomplish the development objectives of the Pyramid Lake Paiute Tribe.

  4. Planktonic diatoms of Lake Ontario

    USGS Publications Warehouse

    Reinwand, Jerry F.

    1969-01-01

    The major species of diatoms in surface collections from Lake Ontario in September 1964 were Asterionella formosa, Fragilaria crotonensis, and Tabellaris fenestrata. Dominant species in the deep-water samples were Stephanodiscus astraea, S. astraea var. mintula, and F. crotonensis. The diatom flora in surface collections varied among several stations in the eastern end of the lake.

  5. GREAT LAKES CONTAMINATED SEDIMENTS PROGRAM

    EPA Science Inventory

    Contaminated sediments are a significant problem in the Great Lakes basin. Although discharges of toxic substances to the Great Lakes have been reduced in the last 20 years, persistent high concentrations of contaminants in the bottom sediments of rivers and harbors have raised...

  6. Venous lakes of the hands

    SciTech Connect

    Levy, J.M.; Hessel, S.J.; Joseph, R.B.; Bodell, L.S.

    1985-09-01

    Following pharmacologic vasodilation, multiple vascular lakes were observed on angiograms of the hand in 55 patients. Most had no history of vascular anomalies or disease. The authors believe that these lakes are venous structures and that their filling is a physiologic phenomenon.

  7. Stream, Lake, and Reservoir Management.

    PubMed

    Mei, Ying; Chang, Chein-Chi; Dong, Zhanfeng; Wei, Li

    2016-10-01

    This review on stream, lake, and reservoir management covers selected 2015 publications on the focus of the following sections: • Biota • Climate effect • Models • Remediation and restoration • Reservoir operations • Stream, Lake, and Reservoir Management • Water quality. PMID:27620102

  8. Pyramid Lake Renewable Energy Project

    SciTech Connect

    John Jackson

    2008-03-14

    The Pyramid Lake Paiute Tribe is a federally recognized Tribe residing on the Pyramid Lake Reservation in western Nevada. The funding for this project was used to identify blind geothermal systems disconnected from geothermal sacred sites and develop a Tribal energy corporation for evaluating potential economic development for profit.

  9. "Lake Woebegone," Twenty Years Later

    ERIC Educational Resources Information Center

    Cannell, John Jacob

    2006-01-01

    Almost 20 years ago, the author wrote--and then privately published--the two "Lake Woebegone" reports, named after Garrison Keillor's mythical Minnesota town where "all the women are strong, all the men are good-looking, and all the children are above average." The first "Lake Woebegone" report documented that all 50 states were testing above the…

  10. Europa's Great Lakes

    NASA Astrophysics Data System (ADS)

    Schmidt, B. E.; Blankenship, D. D.; Patterson, G. W.; Schenk, P. M.

    2012-04-01

    Unique to the surface of Europa, chaos terrain is diagnostic of the properties and dynamics of its icy shell. While models have suggested that partial melt within a thick shell or melt-through of a thin shell may form chaos, neither model has been able to definitively explain all observations of chaos terrain. However, we present a new model that suggests large melt lenses form within the shell and that water-ice interactions above and within these lenses drive the production of chaos. Our analysis of the geomorphology of Conamara Chaos and Thera Macula, was used to infer and test a four-stage lens-collapse chaos formation model: 1) Thermal plumes of warm, pure ice ascend through the shell melting the impure brittle ice above, producing a lake of briny water and surface down draw due to volume reduction. 2) Surface deflection and driving force from the plume below hydraulically seals the water in place. 3) Extension of the brittle ice lid generates fractures from below, allowing brines to enter and fluidize the ice matrix. 4) As the lens and now brash matrix refreeze, thermal expansion creates domes and raises the chaos feature above the background terrain. This new "lense-collapse" model indicates that chaos features form in the presence of a great deal of liquid water, and that large liquid water bodies exist within 3km of Europa's surface comparable in volume to the North American Great Lakes. The detection of shallow subsurface "lakes" implies that the ice shell is recycling rapidly and that Europa may be currently active. In this presentation, we will explore environments on Europa and their analogs on Earth, from collapsing Antarctic ice shelves to to subglacial volcanos in Iceland. I will present these new analyses, and describe how this new perspective informs the debate about Europa's habitability and future exploration.

  11. Lava Lakes on Io?

    NASA Astrophysics Data System (ADS)

    Lopes, R. M. C.; Kamp, L. W.; Smythe, W. D.; Howell, R.; Mouginis-Mark, P.; Kargel, J. S.; Radebaugh, J.; Turtle, E. P.; Perry, J.; Williams, D. A.; Carlson, R. W.; Doute, S.; Galileo NIMS Team

    2003-05-01

    At least 152 active volcanic centers have been identified on Jupiter's moon Io [Lopes et al., 2003, submitted to Icarus]. Eruptions at these centers include lava flows (``Promethean" type eruptions), explosive ``Pillanian" eruptions [Keszthelyi et al., 2001, JGR 106, 33,025-52] and volcanism confined within patera walls (``Lokian", Lopes et al., 2003). Understanding the Lokian eruption mechanism is particularly important because paterae are the most ubiquitous volcanic constructs on Io's surface [Radebaugh et al. 2001, JGR, 106, 33,005-33,020] and patera volcanism is the most common eruption type on Io. We use observations from Galileo's Near-Infrared Mapping Spectrometer (NIMS) and compare them with images from Galileo's Solid State Imaging system (SSI) to map the distribution of thermal emission at several Ionian paterae. This allows us to examine how thermal emission correlates with visible features, and to investigate how thermal emission varies with time. Galileo's close fly-bys of Io from 1999 to 2001 allowed NIMS to observe the volcanoes at relatively high spatial resolution (1-30 km pixel). At these scales, observations of the several paterae reveal that the greatest thermal emission occurs at the edges. This can be explained as the crust of a lava lake breaking up against the base of the patera (caldera) walls, similar to what has been observed at lava lakes on Earth. Comparison with terrestrial analogs shows that several Ionian active paterae, such as Loki, Tupan, and Emakong, have thermal properties consistent with relatively inactive lava lakes on Earth. We discuss these results and their implications for eruption styles and resurfacing on Io. This work was supported in part by NASA's Planetary Geology and Geophysics Program.

  12. Lake-floor sediment texture and composition of a hydrothermally-active, volcanic lake, Lake Rotomahana

    NASA Astrophysics Data System (ADS)

    Pittari, A.; Muir, S. L.; Hendy, C. H.

    2016-03-01

    Young volcanic lakes undergo a transition from rapid, post-eruptive accumulation of volcaniclastic sediment to slower pelagic settling under stable lake conditions, and may also be influenced by sublacustrine hydrothermal systems. Lake Rotomahana is a young (129 year-old), hydrothermally-active, volcanic lake formed after the 1886 Tarawera eruption, and provides a unique insight into the early evolution of volcanic lake systems. Lake-bottom sediment cores, 20-46 cm in length, were taken along a transect across the lake and characterised with respect to stratigraphy, facies characteristics (i.e., grain size, componentry) and pore water silica concentrations. The sediments generally comprise two widespread facies: (i) a lower facies of light grey to grey, very fine lacustrine silt derived from the unconsolidated pyroclastic deposits that mantled the catchment area immediately after the eruption, which were rapidly reworked and redeposited into the lake basin; and (ii) an upper facies of dark, fine-sandy diatomaceous silt, that settled from the pelagic zone of the physically stable lake. Adjacent to sublacustrine hydrothermal vents, the upper dark facies is absent, and the upper part of the light grey to grey silt is replaced by a third localised facies comprised of hydrothermally altered pale yellow to yellowish brown, laminated silt with surface iron-rich encrustations. Microspheres, which are thought to be composed of amorphous silica, although some may be halloysite, have precipitated from pore water onto sediment grains, and are associated with a decrease in pore water silicon concentration. Lake Rotomahana is an example of a recently-stabilised volcanic lake, with respect to sedimentation, that shows signs of early sediment silicification in the presence of hydrothermal activity.

  13. Choking Lake Winnipeg

    NASA Astrophysics Data System (ADS)

    Byrne, J. M.; Little, L. J.; Dodgson, K. A.; MacDonald, R. J.; Graham, J.

    2009-12-01

    The problems of waterway eutrophication and coastal zone hypoxia are reaching epidemic proportions. Fresh water and coastal marine environments around the world are suffering unprecedented pollution loadings. We are developing an education program to address the dramatic need for public, community and K-12 education about the harsh impacts of elevated nutrient loads on fresh and marine water environments. The Lake Winnipeg watershed is adopted as the poster child of fresh water eutrophication in western North America. The watershed, one of the largest on the continent, is in rapid decline due to pollution, population pressures and water diversion. A concerted education program is needed to change personal and society actions that negatively impact the Winnipeg watershed; and the confluence of the watershed - Lake Winnipeg. But the education program goes beyond Lake Winnipeg. Negative impacts of nutrient loads are adversely affecting environments right to the oceans. Major dead zones that are expanding on our continental shelves due to nutrient overloading threaten to coalesce into extensive regions of marine life die-off. This presentation outlines the documentary education production process under development. We are building a series of Public Service Announcements (PSAs) for national television networks. The PSAs will direct educators, stakeholders and citizens to an associated website with educational video clips detailing the issues of eutrophication and hypoxia. The video clips or webisodes, present interviews with leading scientists. The discussions address the causes of the problems, and presents workable solutions to nutrient overloads from a variety of sources. The webisodes are accompanied by notes and advice to teachers on ways and means to use the webisodes in classrooms. The project is fully funed by a group of Canadian Community Foundations, with the understanding the work wil be available free to educators anywhere in the world. Our education

  14. L-Lake macroinvertebrate community

    SciTech Connect

    Specht, W.L.

    1996-06-01

    To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake`s macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of many other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors.

  15. PLAT X41601 EAST (SALT LAKE CITY CEMETERY LOCATER), SALT LAKE ...

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

    PLAT X-4-160-1 EAST (SALT LAKE CITY CEMETERY LOCATER), SALT LAKE CITY, UT. VIEW LOOKING SOUTH AT CEMETERY BETWEEN OLIVE STREET (1020 EAST) AND 1000 EAST STREET, REPHOTOGRAPH OF HISTORIC SHIPLER PHOTO # 12049, UTAH STATE HISTORICAL SOCIETY COLLECTION. - Salt Lake City Cemetery, 200 N Street, Salt Lake City, Salt Lake County, UT

  16. 33 CFR 110.127 - Lake Mohave and Lake Mead, Nevada and Arizona.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lake Mohave and Lake Mead, Nevada... HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.127 Lake Mohave and Lake Mead, Nevada and Arizona. (a) Willow Beach, Ariz. That portion of Lake Mohave enclosed by the shore...

  17. 33 CFR 110.127 - Lake Mohave and Lake Mead, Nevada and Arizona.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Lake Mohave and Lake Mead, Nevada... HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.127 Lake Mohave and Lake Mead, Nevada and Arizona. (a) Willow Beach, Ariz. That portion of Lake Mohave enclosed by the shore...

  18. 78 FR 17097 - Safety Zone; Lake Havasu Triathlon; Lake Havasu City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Lake Havasu Triathlon; Lake Havasu City, AZ... temporary safety zone within the navigable waters of Lake Havasu and the London Bridge Channel for the Lake... Triathlon will consist of 600 participants. The waterside swim course consists of 1500 meters in Lake...

  19. 77 FR 33309 - Safety Zone; Race on the Lake, Onondaga Lake, Syracuse, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-06

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Race on the Lake, Onondaga Lake, Syracuse... temporary safety zone on Onondaga Lake, Syracuse, NY. This safety zone is intended to restrict vessels from a portion of Onondaga Lake during the Race on the Lake powerboat races. This temporary safety...

  20. 76 FR 2579 - Safety Zone; Lake Mead Intake Construction, Lake Mead, Boulder City, NV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-14

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Lake Mead Intake Construction, Lake Mead... establishing a safety zone on the navigable waters of Lake Mead in support of the construction project for Lake... blasting operations for the placement of a water intake pipe in Lake Mead during the first 6 months of...

  1. 75 FR 20920 - Safety Zone; Lake Havasu Grand Prix, Lake Havasu, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-22

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Lake Havasu Grand Prix, Lake Havasu, AZ... temporary safety zone upon the navigable waters of Lake Havasu on the Colorado River in Lake Havasu City, Arizona for the Lake Havasu Grand Prix. This temporary safety zone is necessary to provide for the...

  2. 77 FR 9652 - Proposed CERCLA Administrative Cost Recovery Settlement; Lake Linden Superfund Site in Lake...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-17

    ... AGENCY Proposed CERCLA Administrative Cost Recovery Settlement; Lake Linden Superfund Site in Lake Linden... administrative settlement for recovery of past response costs concerning the Lake Linden Superfund Site in Lake..., Chicago, Illinois, C-14J, 60604, (312) 886-6609. Comments should reference the Lake Linden Superfund...

  3. 75 FR 13232 - Safety Zone; Lake Mead Intake Construction, Lake Mead, Boulder City, NV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-19

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Lake Mead Intake Construction, Lake Mead... establishing a safety zone on the navigable waters of Lake Mead in support of the construction project for Lake... Pipe from Lake Mead throughout 2010. This safety zone is necessary to ensure non-authorized...

  4. LAKE MICHIGAN MASS BALANCE ATRAZINE DATA

    EPA Science Inventory

    The Lake Michigan Mass Balance Study measured PCBs, mercury, trans-nonachlor, and atrazine in rivers, the atmosphere, sediments, lake water, and the food chain. A mathematical model will predict what effect reducing pollution will have on the lake, and its large fish (lake trout ...

  5. LAKE MICHIGAN MASS BALANCE: MODELING PROCESS

    EPA Science Inventory

    The Lake Michigan Mass Balance Study measured PCBs, mercury, trans-nonachlor, and atrazine in rivers, the atmosphere, sediments, lake water, and the food chain. A mathematical model will predict what effect reducing pollution will have on the lake, and its large fish (lake trout ...

  6. LAKE MICHIGAN MASS BALANCE PCB DATA

    EPA Science Inventory

    The Lake Michigan Mass Balance Study measured PCBs, mercury, trans-nonachlor, and atrazine in rivers, the atmosphere, sediments, lake water, and the food chain. A mathematical model will predict what effect reducing pollution will have on the lake, and its large fish (lake trout ...

  7. 27 CFR 9.127 - Cayuga Lake.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Cayuga Lake. 9.127 Section... Lake. (a) Name. The name of the viticultural area described in this section is “Cayuga Lake.” (b) Approved maps. The appropriate map for determining the boundaries of the Cayuga Lake viticultural area...

  8. 27 CFR 9.99 - Clear Lake.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) Boundaries. The Clear Lake viticultural area is located in southwestern Lake County, California. The... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Clear Lake. 9.99 Section 9... TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.99 Clear Lake....

  9. 27 CFR 9.127 - Cayuga Lake.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Cayuga Lake. 9.127 Section... Lake. (a) Name. The name of the viticultural area described in this section is “Cayuga Lake.” (b) Approved maps. The appropriate map for determining the boundaries of the Cayuga Lake viticultural area...

  10. 27 CFR 9.99 - Clear Lake.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Boundaries. The Clear Lake viticultural area is located in southwestern Lake County, California. The... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Clear Lake. 9.99 Section 9... TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.99 Clear Lake....

  11. 27 CFR 9.127 - Cayuga Lake.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Cayuga Lake. 9.127 Section... Lake. (a) Name. The name of the viticultural area described in this section is “Cayuga Lake.” (b) Approved maps. The appropriate map for determining the boundaries of the Cayuga Lake viticultural area...

  12. 27 CFR 9.127 - Cayuga Lake.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Cayuga Lake. 9.127 Section... Lake. (a) Name. The name of the viticultural area described in this section is “Cayuga Lake.” (b) Approved maps. The appropriate map for determining the boundaries of the Cayuga Lake viticultural area...

  13. 27 CFR 9.99 - Clear Lake.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Boundaries. The Clear Lake viticultural area is located in southwestern Lake County, California. The... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Clear Lake. 9.99 Section 9... TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.99 Clear Lake....

  14. 27 CFR 9.127 - Cayuga Lake.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Cayuga Lake. 9.127 Section... Lake. (a) Name. The name of the viticultural area described in this section is “Cayuga Lake.” (b) Approved maps. The appropriate map for determining the boundaries of the Cayuga Lake viticultural area...

  15. 27 CFR 9.99 - Clear Lake.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Boundaries. The Clear Lake viticultural area is located in southwestern Lake County, California. The... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Clear Lake. 9.99 Section 9... TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.99 Clear Lake....

  16. 27 CFR 9.99 - Clear Lake.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Boundaries. The Clear Lake viticultural area is located in southwestern Lake County, California. The... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Clear Lake. 9.99 Section 9... TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.99 Clear Lake....

  17. Estimating the volume of Alpine glacial lakes

    NASA Astrophysics Data System (ADS)

    Cook, S. J.; Quincey, D. J.

    2015-09-01

    Supraglacial, moraine-dammed and ice-dammed lakes represent a potential glacial lake outburst flood (GLOF) threat to downstream communities in many mountain regions. This has motivated the development of empirical relationships to predict lake volume given a measurement of lake surface area obtained from satellite imagery. Such relationships are based on the notion that lake depth, area and volume scale predictably. We critically evaluate the performance of these existing empirical relationships by examining a global database of measured glacial lake depths, areas and volumes. Results show that lake area and depth are not always well correlated (r2 = 0.38), and that although lake volume and area are well correlated (r2 = 0.91), there are distinct outliers in the dataset. These outliers represent situations where it may not be appropriate to apply existing empirical relationships to predict lake volume, and include growing supraglacial lakes, glaciers that recede into basins with complex overdeepened morphologies or that have been deepened by intense erosion, and lakes formed where glaciers advance across and block a main trunk valley. We use the compiled dataset to develop a conceptual model of how the volumes of supraglacial ponds and lakes, moraine-dammed lakes and ice-dammed lakes should be expected to evolve with increasing area. Although a large amount of bathymetric data exist for moraine-dammed and ice-dammed lakes, we suggest that further measurements of growing supraglacial ponds and lakes are needed to better understand their development.

  18. 33 CFR 125.08 - Great Lakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Great Lakes. 125.08 Section 125... VESSELS § 125.08 Great Lakes. The term Great Lakes as used in the regulations in this subchapter shall include the Great Lakes and their connecting and tributary waters....

  19. EPA Research Strengthens Great Lakes Restoration Initiative

    EPA Science Inventory

    As the largest group of freshwater lakes on Earth, the Great Lakes (Lakes Erie, Huron, Michigan, Ontario and Superior) are a source of economic prosperity, recreation and raw materials. Human activity, however, has resulted in pollution and other stressors. The Great Lakes curren...

  20. 33 CFR 125.08 - Great Lakes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Great Lakes. 125.08 Section 125... VESSELS § 125.08 Great Lakes. The term Great Lakes as used in the regulations in this subchapter shall include the Great Lakes and their connecting and tributary waters....

  1. TOXAPHENE IN THE GREAT LAKES. (R825246)

    EPA Science Inventory

    This paper presents the most current data for toxaphene in the water, sediments, and biota of the Laurentian Great Lakes of North America. Concentrations in water range from 1.1 ng/L in Lake Superior to 0.17 ng/L in Lake Ontario. Lake Superior has the highest water concentrati...

  2. The Great Lakes' regional climate regimes

    NASA Astrophysics Data System (ADS)

    Sugiyama, Noriyuki

    For the last couple of decades, the Great Lakes have undergone rapid surface warming. In particular, the magnitude of the summer surface-warming trends of the Great Lakes have been much greater than those of surrounding land (Austin and Colman, 2007). Among the Great Lakes, the deepest Lake Superior exhibited the strongest warming trend in its annual, as well as summer surface water temperature. We find that many aspects of this behavior can be explained in terms of the tendency of deep lakes to exhibit multiple regimes characterized, under the same seasonally varying forcing, by the warmer and colder seasonal cycles exhibiting different amounts of wintertime lake-ice cover and corresponding changes in the summertime lake-surface temperatures. In this thesis, we address the problem of the Great Lakes' warming using one-dimensional lake modeling to interpret diverse observations of the recent lake behavior. (Abstract shortened by ProQuest.).

  3. Possible temperate lakes on Titan

    NASA Astrophysics Data System (ADS)

    Vixie, Graham; Barnes, Jason W.; Jackson, Brian; Rodriguez, Sébastien; Le Mouélic, Stéphane; Sotin, Christophe; MacKenzie, Shannon; Wilson, Paul

    2015-09-01

    We analyze southern mid-latitude albedo-dark features on Titan observed by Cassini's Visual and Infrared Mapping Spectrometer (VIMS). In exploring the nature of these features we consider their morphology, albedo, and specular reflectivity. We suggest that they represent candidates for potential temperate lakes. The presence of lakes at the mid-latitudes would indicate that surface liquid can accumulate and remain stable away from Titan's poles. Candidate lakes were identified by looking for possible shorelines with lacustrine morphology. Then, we applied an atmospheric correction that empirically solved for their surface albedo. Finally, we looked for a specular reflection of the sky in the identified candidates. Using this prescription, we find two candidates that remain as potential temperature lakes. If candidate features do represent temperate lakes on Titan, they have implications for formation mechanisms such as clouds and rainfall or, in low elevation areas, percolation and subsurface flow. Clouds were observed near candidate lake locations on the T66 flyby and this latitude band showed many clouds during southern summer. Our techniques can be applied to areas of Titan that lack RADAR coverage to search for mid- and low-latitude lakes in the future.

  4. Rehabilitation of Delavan Lake, Wisconsin

    USGS Publications Warehouse

    Robertson, Dale M.; Goddard, Gerald L.; Helsel, D.R.; MacKinnon, Kevin L.

    2009-01-01

    A comprehensive rehabilitation plan was developed and implemented to shift Delavan Lake, Wisconsin, from a hypereutrophic to a mesotrophic condition. The plan was threefold: (1) reduce external phosphorus (P) loading by applying Best Management Practices in the watershed, enhance an existing wetland, and short-circuit the inflows through the lake, (2) reduce internal P loading by treating the sediments with alum and removing carp, and (3) rehabilitate the fishery by removing carp and bigmouth buffalo and adding piscivores (biomanipulation). The first and second parts of the plan met with only limited success. With only minor reductions in internal and external P loading, P concentrations in the lake returned to near pre-treatment concentrations. The intensive biomanipulation and resulting trophic cascade (increased piscivores, decreased planktivores, increased large zooplankton populations, and reduced phytoplankton populations) eliminated most of the original problems in the lake (blue-green algal blooms and limited water clarity). However, now there is extensive macrophyte growth and abundant filamentous algae. Without significantly reducing the sources of the problems (high P loading) in Delavan Lake, the increased water clarity may not last. With an improved understanding of the individual components of this rehabilitation program, better future management plans can be developed for Delavan Lake and other lakes and reservoirs with similar eutrophication problems.

  5. The Stability of Lava Lakes

    NASA Astrophysics Data System (ADS)

    Witham, F.; Llewellin, E. W.; Woods, A. W.; Gladstone, C.

    2007-12-01

    Lava lakes may exhibit complex cycles of filling and draining on time-scales of hours to weeks. Such activity is recorded at Pu`u `O`o, Hawai`i. Other examples, e.g. Erta Ale in Ethiopia, do not display these draining episodes; instead an 'equilibrium' system is observed in which the lake may persist for years. We present the results of a theoretical and experimental investigation of lava lakes and identify behavioural regimes distinguished by system geometry and gas content. Laboratory analogue modelling shows that even a simple conduit-lake system, driven by a constant gas flux, can display steady-state equilibrium or cyclic behaviour, depending on the rate of gas flux. A theoretical approach to the same system captures this range of behaviour. By testing the stability of an 'equilibrium' lake to small perturbations, we show that the degree of stability is controlled by the ratio of conduit to lake areas, and the gas volume fraction at the top of the conduit. Despite the simplicity of the modelled system, a rich spectrum of behaviour is found. The model predicts that a stable system must drain over time. This implies that lakes which exhibit ongoing degassing for years or decades (e.g. Erta Ale) either must have an exogenous supply of gas bubbles from depth, or an effective conduit convection mechanism must exist.

  6. 33 CFR 162.220 - Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Hoover Dam, Lake Mead, and Lake... REGULATIONS § 162.220 Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev. (a) Lake Mead and Lake Mohave; restricted areas—(1) The areas. That portion of Lake Mead extending 700 feet upstream...

  7. 33 CFR 162.220 - Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Hoover Dam, Lake Mead, and Lake... REGULATIONS § 162.220 Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev. (a) Lake Mead and Lake Mohave; restricted areas—(1) The areas. That portion of Lake Mead extending 700 feet upstream...

  8. Microplastics in Taihu Lake, China.

    PubMed

    Su, Lei; Xue, Yingang; Li, Lingyun; Yang, Dongqi; Kolandhasamy, Prabhu; Li, Daoji; Shi, Huahong

    2016-09-01

    In comparison with marine environments, the occurrence of microplastics in freshwater environments is less understood. In the present study, we investigated microplastic pollution levels during 2015 in Taihu Lake, the third largest Chinese lake located in one of the most developed areas of China. The abundance of microplastics reached 0.01 × 10(6)-6.8 × 10(6) items/km(2) in plankton net samples, 3.4-25.8 items/L in surface water, 11.0-234.6 items/kg dw in sediments and 0.2-12.5 items/g ww in Asian clams (Corbicula fluminea). The average abundance of microplastics was the highest in plankton net samples from the southeast area of the lake and in the sediments from the northwest area of the lake. The northwest area of the lake was the most heavily contaminated area of the lake, as indicated by chlorophyll-α and total phosphorus. The microplastics were dominated by fiber, 100-1000 μm in size and cellophane in composition. To our best knowledge, the microplastic levels measured in plankton net samples collected from Taihu Lake were the highest found in freshwater lakes worldwide. The ratio of the microplastics in clams to each sediment sample ranged from 38 to 3810 and was negatively correlated to the microplastic level in sediments. In brief, our results strongly suggest that high levels of microplastics occurred not only in water but also in organisms in Taihu Lake. PMID:27381875

  9. Monitoring Change in Great Salt Lake

    NASA Astrophysics Data System (ADS)

    Naftz, David; Angeroth, Cory; Freeman, Michael; Rowland, Ryan; Carling, Gregory

    2013-08-01

    Great Salt Lake is the largest hypersaline lake in the Western Hemisphere and the fourth largest terminal lake in the world (Figure 1). The open water and adjacent wetlands of the Great Salt Lake ecosystem support millions of migratory waterfowl and shorebirds from throughout the Western Hemisphere [Aldrich and Paul, 2002]. In addition, the area is of important economic value: Brine shrimp (Artemia franciscana) residing in Great Salt Lake support an aquaculture shrimp cyst industry with annual revenues as high as $60 million.

  10. Early eutrophication in the lower great lakes:.

    PubMed

    Schelske, C L; Stoermer, E F; Conley, D J; Robbins, J A; Glover, R M

    1983-10-21

    New Evidence from Biogenic Silica in Sediments New evidence from studies of biogenic silica and diatoms in sediment cores indicates that eutrophication in the lower Great Lakes resulted from nutrient enrichment associated with early settlement and forest clearance. Diatom production peaked from 1820 to 1850 in Lake Ontario, at about 1880 in Lake Erie, but not until 1970 in Lake Michigan. This is the first reported sediment record of the silica-depletion sequence for the Great Lakes. PMID:17734831

  11. Lake trout in the Great Lakes: Basin-wide stock collapse and binational restoration

    USGS Publications Warehouse

    Hansen, Michael J.

    1999-01-01

    The lake trout (Salvelinus namaycush) was important to the human settlement of each of the Great Lakes, and underwent catastrophic collapses in each lake in the nineteenth and twentieth centuries. The timing of lake trout stock collapses were different in each lake, as were the causes of the collapses, and have been the subject of much scientific inquiry and debate. The purpose of this chapter is to summarize and review pertinent information relating historical changes in Great Lakes lake trout stocks, binational efforts to restore those stocks, and progress toward stock restoration. This presentation attempts to generalize patterns across the Great Lakes, rather than to focus within each lake. Lake specific analyses have been used to understand lake specific causes and effects, but there is continuing debate about some of these causes and effects. A basinwide review may suggest mechanisms for observed changes that are not evident by lake specific analysis.

  12. LIMNOLOGICAL COMPARISON OF CULTURALLY EUTROPHIC SHAGAWA LAKE AND ADJACENT OLIGOTROPHIC BURNTSIDE LAKE, MINNESOTA

    EPA Science Inventory

    Limnological characteristics for 1971-1972 of culturally eutrophic Shagawa Lake, Minnesota, were compared to those of the immediately upstream, oligotrophic Burntside Lake to evaluate the effects of domestic waste-water discharge to Shagawa Lake. Typical characteristics of Shagaw...

  13. Predicting Maximum Lake Depth from Surrounding Topography

    PubMed Central

    Hollister, Jeffrey W.; Milstead, W. Bryan; Urrutia, M. Andrea

    2011-01-01

    Information about lake morphometry (e.g., depth, volume, size, etc.) aids understanding of the physical and ecological dynamics of lakes, yet is often not readily available. The data needed to calculate measures of lake morphometry, particularly lake depth, are usually collected on a lake-by-lake basis and are difficult to obtain across broad regions. To span the gap between studies of individual lakes where detailed data exist and regional studies where access to useful data on lake depth is unavailable, we developed a method to predict maximum lake depth from the slope of the topography surrounding a lake. We use the National Elevation Dataset and the National Hydrography Dataset – Plus to estimate the percent slope of surrounding lakes and use this information to predict maximum lake depth. We also use field measured maximum lake depths from the US EPA's National Lakes Assessment to empirically adjust and cross-validate our predictions. We were able to predict maximum depth for ∼28,000 lakes in the Northeastern United States with an average cross-validated RMSE of 5.95 m and 5.09 m and average correlation of 0.82 and 0.69 for Hydrological Unit Code Regions 01 and 02, respectively. The depth predictions and the scripts are openly available as supplements to this manuscript. PMID:21984945

  14. Western Arctic Vulnerability to Warming over the past 3.6 Myr: Lessons from sediments drilled at Lake El'gygytgyn, Western Beringia

    NASA Astrophysics Data System (ADS)

    Brigham-Grette, J.; Melles, M.; Minyuk, P.; Lake El'gygytgyn Science Team

    2011-12-01

    some have inferred from marine isotopic data. Warm interglacial portions of the core investigated so far are those correlative with MIS 5e, 9, 11 and 31 that differ in character, due to orbital forcing and feedbacks. The lithofacies can be linked directly to other proxies of climate change and allow us to interpret climatic influences on the watershed as well as changing conditions related to lake productivity, lake ice cover persistence, runoff and clastic input and vegetation in the basin. Multi-proxy evidence shows that interglacials MIS 9, 11 and 31 were remarkably warmer than MIS 5e. A warm MIS 31 at Lake E may have occurred half a precession cycle before the last time ANDRILL shows direct evidence of the collapse of WAIS. MIS 11 shows surprising structural similarities to Lake Baikal and Dome C ice core paleorecords but is remarkably warm. The climate record from Lake E, especially the history of past interglacials, provides a fresh means of testing what controls polar amplification over time.

  15. Characterization of Lake Michigan coastal lakes using zooplankton assemblages

    USGS Publications Warehouse

    Whitman, Richard L.; Nevers, Meredith B.; Goodrich, Maria L.; Murphy, Paul C.; Davis, Bruce M.

    2004-01-01

    Zooplankton assemblages and water quality were examined bi-weekly from 17 April to 19 October 1998 in 11 northeastern Lake Michigan coastal lakes of similar origin but varied in trophic status and limnological condition. All lakes were within or adjacent to Sleeping Bear Dunes National Lakeshore, Michigan. Zooplankton (principally microcrustaceans and rotifers) from triplicate Wisconsin net (80 I?m) vertical tows taken at each lake's deepest location were analyzed. Oxygen-temperature-pH-specific conductivity profiles and surface water quality were concurrently measured. Bray-Curtis similarity analysis showed small variations among sample replicates but large temporal differences. The potential use of zooplankton communities for environmental lake comparisons was evaluated by means of BIOENV (Primer 5.1) and principal component analyses. Zooplankton analyzed at the lowest identified taxonomic level yielded greatest sensitivity to limnological variation. Taxonomic and ecological aggregations of zooplankton data performed comparably, but less well than the finest taxonomic analysis. Secchi depth, chlorophyll a, and sulfate concentrations combined to give the best correlation with patterns of variation in the zooplankton data set. Principal component analysis of these variables revealed trophic status as the most influential major limnological gradient among the study lakes. Overall, zooplankton abundance was an excellent indicator of variation in trophic status.

  16. Lake restoration technology transfer assessment

    SciTech Connect

    Daschbach, M.H.; Roe, E.M.; Sharpe, W.E.

    1982-06-01

    Based upon a review of the eutrophication problem and its impact on lake restoration (LR) programs, treatment of the relatively new problem of acid deposition and its impact on LR activities, consideration of the LR programs of the Environmental Protection Agency and several states, and a review of individual LR technology transfer publications, it is recommended that new LR technology transfer programs be given a low priority until more new information is available on the restoration of acidified lakes. Both primary and secondary users of LR research, technology transfer documents, and public awareness documents were considered in this assessment. Primary users included the general public and recreationists, lakeshore property owners, lake/homeowner associations, lake/sanitary districts, and research and environmental organizations; secondary users included state/county/local officials who administer/manage water-related regulations/activities. 4 tables.

  17. LAKE WATER TEMPERATURE SIMULATION MODEL

    EPA Science Inventory

    Functional relationships to describe surface wind mixing, vertical turbulent diffusion, convective heat transfer, and radiation penetration based on data from lakes in Minnesota have been developed. hese relationships have been introduced by regressing model parameters found eith...

  18. Spatial variation among lakes within landscapes: Ecological organization along lake chains

    USGS Publications Warehouse

    Soranno, Patricia A.; Webster, Katherine E.; Riera, Joan L.; Kratz, Timothy K.; Baron, Jill S.; Bukaveckas, Paul A.; Kling, George; White, David S.; Caine, Nel; Lathrop, Richard C; Leavitt, Peter R.

    1999-01-01

    Although limnologists have long been interested in regional patterns in lake attributes, only recently have they considered lakes connected and organized across the landscape, rather than as spatially independent entities. Here we explore the spatial organization of lake districts through the concept of landscape position, a concept that considers lakes longitudinally along gradients of geomorphology and hydrology. We analyzed long-term chemical and biological data from nine lake chains (lakes in a series connected through surface or groundwater flow) from seven lake districts of diverse hydrologic and geomorphic settings across North America. Spatial patterns in lake variables driven by landscape position were surprisingly common across lake districts and across a wide range of variables. On the other hand, temporal patterns of lake variables, quantified using synchrony, the degree to which pairs of lakes exhibit similar dynamics through time, related to landscape position only for lake chains with lake water residence times that spanned a wide range and were generally long (close to or greater than 1 year). Highest synchrony of lakes within a lake chain occurred when lakes had short water residence times. Our results from both the spatial and temporal analyses suggest that certain features of the landscape position concept are robust enough to span a wide range of seemingly disparate lake types. The strong spatial patterns observed in this analysis, and some unexplained patterns, suggest the need to further study these scales and to continue to view lake ecosystems spatially, longitudinally, and broadly across the landscape.

  19. Lake County renewable energy plan

    SciTech Connect

    Not Available

    1984-10-01

    This report documents the preparation of a renewable energy plan for Lake County, Oregon. It is the County's intention to adopt this plan as a supporting document to its Comprehensive Plan and implementing ordinances. The consideration of renewable energy in its land-use planning program is a statutory requirement for Lake County, and under the provisions of the Pacific Northwest Electric Power Planning and Conservation Act such renewable resource planning also fulfills regional energy objectives on a local level.

  20. Burrowing saves Lake Erie clams

    USGS Publications Warehouse

    Nichols, S. Jerrine; Wilcox, Douglas A.

    1997-01-01

    Freshwater unionid clams in North America have been virtually eliminated from waters that are colonized by zebra mussels. Near total mortality has been reported in western Lake Erie, but we have discovered a large population of native clams in a Lake Erie wetland that shows little sign of infestation. Field observations and laboratory experiments show that warm summer water temperatures and soft, silt-clay sediments trigger burowing by clams. This discourages infestation and physically removes any attached zebra mussels.

  1. Global lake surface water temperatures from ATSR

    NASA Astrophysics Data System (ADS)

    MacCallum, Stuart; Merchant, Christopher J.; Layden, Aisling

    2013-04-01

    The ATSR Reprocessing for Climate - Lake (ARC-Lake) project applies optimal estimation (OE) retrievals and probabilistic cloud screening methods to provide lake surface water temperature (LSWT) estimates from the series of (Advanced) Along-Track Scanning Radiometers. This methodology is generic (i.e. applicable to all lakes) as variations in physical properties such as elevation, salinity, and atmospheric conditions are accounted for through the forward modelling of observed radiances. In the initial phases of ARC-Lake, LSWTs were obtained for 258 of Earth's largest lakes. In the final phase of the project, the dataset is extended by applying the OE methodology to smaller lakes, providing LSWT data from 1991 to 2012 for approximately 1000 lakes. In this presentation we will provide an overview of the ARC-Lake project, its publically available data products and some applications of these products.

  2. Mitigation alternatives for L Lake

    SciTech Connect

    Moore, D.B.

    1988-11-03

    The current condition of L Lake/Steel Creek was summarized in a report to SCDHEC in June 1988 which reported that the L Lake and Steel Creek ecosystems were adequately developing towards balanced biological communities. If mitigation for L Lake inputs, specifically temperature and nutrients, are required, several viable alternatives are available. A report prepared by Spencer in 1986 discusses the various options available for cooling L-Reactor discharges. In effect, a small cooling tower is the only realistic solution to reducing effluent temperatures. Nutrient mitigation can take several approaches including upstream sewage treatment, hypolimnetic withdrawal, dilution of input water by Par Pond water, precipitation of nutrients, and sediment oxidation. None of these systems would influence the thermal regime, but would significantly reduce nutrient input into the system. One beneficial use of L-Lake thermal effluents is algaculture, the production of useful algae. A document prepared in 1988 concludes that algaculture is a technically and economically feasible mitigation alternative for L Lake and could allow L Lake to be handled under Section 318 of the Clean Water Act.

  3. The size-distribution of Earth's lakes.

    PubMed

    Cael, B B; Seekell, D A

    2016-01-01

    Globally, there are millions of small lakes, but a small number of large lakes. Most key ecosystem patterns and processes scale with lake size, thus this asymmetry between area and abundance is a fundamental constraint on broad-scale patterns in lake ecology. Nonetheless, descriptions of lake size-distributions are scarce and empirical distributions are rarely evaluated relative to theoretical predictions. Here we develop expectations for Earth's lake area-distribution based on percolation theory and evaluate these expectations with data from a global lake census. Lake surface areas ≥8.5 km(2) are power-law distributed with a tail exponent (τ = 1.97) and fractal dimension (d = 1.38), similar to theoretical expectations (τ = 2.05; d = 4/3). Lakes <8.5 km(2) are not power-law distributed. An independently developed regional lake census exhibits a similar transition and consistency with theoretical predictions. Small lakes deviate from the power-law distribution because smaller lakes are more susceptible to dynamical change and topographic behavior at sub-kilometer scales is not self-similar. Our results provide a robust characterization and theoretical explanation for the lake size-abundance relationship, and form a fundamental basis for understanding and predicting patterns in lake ecology at broad scales. PMID:27388607

  4. INTERSECTION OF 445 NORTH & 1040 EAST, SALT LAKE CITY, ...

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

    INTERSECTION OF 445 NORTH & 1040 EAST, SALT LAKE CITY, UT. VIEW LOOKING SOUTH. REPHOTOGRAPH OF HISTORIC SHIPLER PHOTO # 18272, UTAH STATE HISTORICAL SOCIETY COLLECTION. - Salt Lake City Cemetery, 200 N Street, Salt Lake City, Salt Lake County, UT

  5. 200 MAIN STREET, SALT LAKE CITY, UT. VIEW LOOKING EAST ...

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

    200 MAIN STREET, SALT LAKE CITY, UT. VIEW LOOKING EAST OF "MAIN' STREET. REPHOTOGRAPH OF HISTORIC SHIPLER PHOTO # 18273, UTAH STATE HISTORICAL SOCIETY COLLECTION. - Salt Lake City Cemetery, 200 N Street, Salt Lake City, Salt Lake County, UT

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

    USGS Publications Warehouse

    Bradner, L.A.

    1986-01-01

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

  7. Lake water quality mapping from LANDSAT

    NASA Technical Reports Server (NTRS)

    Scherz, J. P.

    1977-01-01

    The lakes in three LANDSAT scenes were mapped by the Bendix MDAS multispectral analysis system. Field checking the maps by three separate individuals revealed approximately 90-95% correct classification for the lake categories selected. Variations between observers was about 5%. From the MDAS color coded maps the lake with the worst algae problem was easily located. This lake was closely checked and a pollution source of 100 cows was found in the springs which fed this lake. The theory, lab work and field work which made it possible for this demonstration project to be a practical lake classification procedure are presented.

  8. Lake water quality mapping from Landsat

    NASA Technical Reports Server (NTRS)

    Scherz, J. P.

    1977-01-01

    In the project described remote sensing was used to check the quality of lake waters. The lakes of three Landsat scenes were mapped with the Bendix MDAS multispectral analysis system. From the MDAS color coded maps, the lake with the worst algae problem was easily located. The lake was closely checked, and the presence of 100 cows in the springs which fed the lake could be identified as the pollution source. The laboratory and field work involved in the lake classification project is described.

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

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

  10. Salt Lake City, Utah

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The 2002 Winter Olympics are hosted by Salt Lake City at several venues within the city, in nearby cities, and within the adjacent Wasatch Mountains. This simulated natural color image presents a late spring view of north central Utah that includes all of the Olympic sites. The image extends from Ogden in the north, to Provo in the south; and includes the snow-capped Wasatch Mountains and the eastern part of the Great Salt Lake.

    This image was acquired on May 28, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18,1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. ASTER is the only high resolution imaging sensor on Terra. The Terra mission is part of NASA's Earth Science Enterprise, a long-term research and technology program designed to examine Earth's land, oceans, atmosphere, ice and life as a total integrated system.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution

  11. Lakes in Valles Marineris

    NASA Astrophysics Data System (ADS)

    Lucchitta, Baerbel K.

    2010-10-01

    The paper reviews the evolution of hypotheses of lakes in Valles Marineris through observations made from the time of Mariner and continuing through the Viking, MGS, MO, MEx, and MRO missions. Several pertinent findings from these missions are addressed, including: The morphology and composition of the interior layered deposits (ILD); the question whether ILD are deposited inside the troughs or exhumed from the walls; the possible existence of ancestral basins; the derivation of water; arguments for an origin as aqueous, eolian, or pyroclastic sediments, or sub/ice volcanoes; origin of inclined layers, mounds and moats; and age relations of features within and peripheral to the troughs. A possible scenario begins with the collapse of ice-charged ground into ancestral basins along structural planes of weakness due to Tharsis stresses, about 3.5 Ga ago. The basins rapidly filled with water from ground ice, subterranean aquifers, or nearby valley networks. The water spilled out of the peripheral troughs and flowed across high plateaus into early outflow channels. The ancestral basins then filled with sediments derived from valley networks or from trapped eolian or pyroclastic deposits. Alternatively, volcanoes rose under the water or ice to form tuyas. The water was highly acidic, and sediments may have been deposited directly as evaporites or were later altered to evaporites by the brines or by hydrothermal activity. Percolating fluids produced iron oxide concretions. Similar alteration would have affected the putative volcanoes. Most of the ILD were emplaced early in the troughs' history. Shortly thereafter, more water erupted from the peripheral troughs and formed additional chaos and outflow channels. The ancestral basins were breached by erosion and tectonism, and the through-going Coprates/Ius graben system developed. Major lakes within the Valles Marineris dried up and vigorous wind erosion reduced the friable, evaporite-rich sediments to isolated mounds

  12. Dongting Lake, China

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These images show dramatic change in the water at Dongting Lake in Hunan province, China. A flood crest surged down the Yangtze River in late August of this year, but the embankments made by residents there held. The left image was acquired on September 2, 2002 and shows the extent of the lake. The right image was obtained March 19, 2002 before the flooding began.

    These images were acquired on September 2, 2002 and March 19,2002 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image Earth for the next 6 years to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER will provide scientists in numerous disciplines with critical information for surface mapping, and monitoring dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    Dr. Anne Kahle at NASA's Jet Propulsion Laboratory, Pasadena, California, is the U.S. Science team leader; Bjorn Eng of JPL is the project manager. The Terra mission is part of NASA's Earth Science Enterprise, a long-term research and technology program designed to examine Earth's land, oceans, atmosphere, ice and life as

  13. Hydrology of Central Florida Lakes - A Primer

    USGS Publications Warehouse

    Schiffer, Donna M.

    1998-01-01

    INTRODUCTION Lakes are among the most valued natural resources of central Florida. The landscape of central Florida is riddled with lakeswhen viewed from the air, it almost seems there is more water than land. Florida has more naturally formed lakes than other southeastern States, where many lakes are created by building dams across streams. The abundance of lakes on the Florida peninsula is a result of the geology and geologic history of the State. An estimated 7,800 lakes in Florida are greater than 1 acre in surface area. Of these, 35 percent are located in just four counties (fig. 1): Lake, Orange, Osceola, and Polk (Hughes, 1974b). Lakes add to the aesthetic and commercial value of the area and are used by many residents and visitors for fishing, boating, swimming, and other types of outdoor recreation. Lakes also are used for other purposes such as irrigation, flood control, water supply, and navigation. Residents and visitors commonly ask questions such as Whyare there so many lakes here?, Why is my lake drying up (or flooding)?, or Is my lake spring-fed? These questions indicate that the basic hydrology of lakes and the interaction of lakes with ground water and surface water are not well understood by the general population. Because of the importance of lakes to residents of central Florida and the many questions and misconceptions about lakes, this primer was prepared by the U.S. Geological Survey (USGS) in cooperation with the St. Johns River Water Management District and the South Florida Water Management District. The USGS has been collecting hydrologic data in central Florida since the 1920s, obtaining valuable information that has been used to better understand the hydrology of the water resources of central Florida, including lakes. In addition to data collection, as of 1994, the USGS had published 66 reports and maps on central Florida lakes (Garcia and Hoy, 1995). The main purpose of this primer is to describe the hydrology of lakes in central

  14. Numerical simulations of Lake Vostok

    NASA Astrophysics Data System (ADS)

    Curchitser, E.; Tremblay, B.

    2003-04-01

    Numerical simulations of Lake Vostok We present a systematic approach towards a realistic hydrodynamic model of lake Vostok. The lake is characterized by the unusual combination of size (permitting significant geostrophic motion) and an overlying ice sheet several kilometers thick. A priori estimates of the circulation in the deep lake predict a mostly geostrophic circulation driven by horizontal temperature gradients produced by the pressure-dependent freezing point at the base of the (non-uniform) ice sheet. Further preliminary (remote) research has revealed the steep topography and the elliptical geometry of the lake. A three dimensional, primitive equation, free surface, model is used as a starting point for the Lake configuration. We show how the surface pressure gradient forces are modified to permit a simulation that includes the hydrostatic effects of the overlying ice sheet. A thermodynamic ice model is coupled with the circulation component to simulate the ice accretion/melting at the base of the ice sheet. A stretching of the terrain following vertical coordinate is used to resolve the boundary layer in the ice/water interface. Furthermore, the terrain-following coordinate evolves in time, and is used to track the evolution of the ice sheet due to ice accretion/melting. Both idealized and realistic ice sheet bottom topographies (from remote radar data) are used to drive the simulations. Steady state and time evolving simulations (i.e., constant and evolving ice sheet geometry) will be descirbed, as well as a comparison to an idealized box model (Tremblay, Clarke, and Hohman). The coastline and lake bathymetry used in the simulation are derived from radar data and are accurately represented in our model.

  15. Eutrophication of the St. Lawrence Great Lakes

    USGS Publications Warehouse

    Beeton, Alfred M.

    1965-01-01

    Lakes Huron, Michigan, and Superior are classified as oligotrophic lakes on the basis of their biological, chemical, and physical characteristics. Lake Ontario, although rich in nutrients, is morphometrically oligotrophic or mesotrophic because of its large area of deep water. Lake Erie, the most productive of the lakes and the shallowest, is eutrophic. Several changes commonly associated with eutrophication in small lakes have been observed in the Great Lakes. These changes apparently reflect accelerated eutrophication in the Great Lakes due to man's activity. Chemical data compiled from a number of sources, dating as early as 1854, indicate a progressive increase in the concentrations of various major ions and total dissolved solids in all of the lakes except Lake Superior. The plankton has changed somewhat in Lake Michigan and the plankton, benthos, and fish populations of Lake Erie are greatly different today from those of the past. An extensive area of hypolimnetic water of Lake Erie has developed low dissolved oxygen concentrations in late summer within recent years.

  16. Lake and reservoir restoration guidance manual: first edition

    SciTech Connect

    Moore, L.; Thornton, K.

    1988-02-01

    This manual provides guidance to lake managers, homeowners, lake associations, and laypersons on lake and reservoir restoration, management and protection. It also provides information on how to identify lake problems, evaluate practices for restoring and protection lakes, watershed management, and creating a lake-management plan.

  17. 1. GENERAL VIEW OF THE LOWER END OF TWIN LAKES ...

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

    1. GENERAL VIEW OF THE LOWER END OF TWIN LAKES SHOWING THE HISTORIC OUTLET WORKS AT THE EDGE OF THE WATER NEAR CENTER OF THE PHOTO WITH THE NEW TWIN LAKES DAM JUST BEHIND. VIEW LOOKING SOUTHEAST. - Twin Lakes Dam & Outlet Works, Beneath Twin Lakes Reservoir, T11S, R80W, S22, Twin Lakes, Lake County, CO

  18. Lake Naivasha, Kenya

    NASA Technical Reports Server (NTRS)

    2008-01-01

    If you live in Europe and buy roses, there is a good chance that they were grown in Kenya specifically, in one of the colossal greenhouses that blot out the once wild shores of Lake Naivasha, 90km north-west of Nairobi. Some 25% of Europe's cut flowers come from Kenya. After a tentative start in the 1980s the industry is now the country's third-largest foreign-currency earner, bringing in $120m a year. But the recent violence in Kenya is having a major impact on the flower growers. A local trade union says 3,000 of the 30,000 workers employed in Naivasha's flower farms have abandoned their jobs. Kenya emerged as a flower power when Israel scaled down its own industry. It has since lost business to neighboring Ethiopia, which offers tax breaks and better security, but Naivasha's perfect intensity of sunlight and days of near-constant length should keep it on top.

    The ASTER image was acquired February 2, 2008, covers an area of 25 x 26.6 km, and is located near 0.8 degrees south latitude, 36.4 degrees east longitude.

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

  19. Exploring trends, causes, and consequences of declining lipids in Lake Superior lake trout

    EPA Science Inventory

    The ability of lake trout to forage in deepwater habitats is facilitated by high lipid content, which affords buoyancy. In Lake Superior, lean lake trout historically occupied depths < 80 m, and siscowet lake trout occupied depths > 80 m. Siscowets have been known f...

  20. What can the National Lake Assessment Tell Us about Ecosystem Service Benefits in Lakes

    EPA Science Inventory

    The condition of lakes, ponds, and reservoirs is often viewed as existing along a continuum from pristine to impacted. The 2007 National Lake Survey was conducted to assess the condition of the nation’s lakes. Over 1,000 lakes were surveyed and detailed physical and chemical da...

  1. Estimate of net trophic transfer efficiency of PCBs to Lake Michigan lake trout from their prey

    USGS Publications Warehouse

    Madenjian, Charles P.; Hesselberg, Robert J.; DeSorcie, Timothy J.; Schmidt, Larry J.; Stedman, Ralph M.; Quintal, Richard T.; Begnoche, Linda J.; Passino-Reader, Dora R.

    1998-01-01

    Most of the polychlorinated biphenyl (PCB) body burden accumulated by lake trout (Salvelinus namaycush) from the Laurentian Great Lakes is from their food. We used diet information, PCB determinations in both lake trout and their prey, and bioenergetics modeling to estimate the efficiency with which Lake Michigan lake trout retain PCBs from their food. Our estimates were the most reliable estimates to date because (a) the lake trout and prey fish sampled during our study were all from the same vicinity of the lake, (b) detailed measurements were made on the PCB concentrations of both lake trout and prey fish over wide ranges in fish size, and (c) lake trout diet was analyzed in detail over a wide range of lake trout size. Our estimates of net trophic transfer efficiency of PCBs to lake trout from their prey averaged from 0.73 to 0.89 for lake trout between the ages of 5 and 10 years old. There was no evidence of an upward or downward trend in our estimates of net trophic transfer efficiency for lake trout between the ages of 5 and 10 years old, and therefore this efficiency appeared to be constant over the duration of the lake trout's adult life in the lake. On the basis of our estimtes, lake trout retained 80% of the PCBs that are contained within their food.

  2. 33 CFR 162.140 - Connecting waters from Lake Huron to Lake Erie; miscellaneous rules.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; miscellaneous rules. 162.140 Section 162.140 Navigation and Navigable Waters COAST... NAVIGATION REGULATIONS § 162.140 Connecting waters from Lake Huron to Lake Erie; miscellaneous rules....

  3. 33 CFR 162.130 - Connecting waters from Lake Huron to Lake Erie; general rules.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; general rules. 162.130 Section 162.130 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.130 Connecting waters from Lake Huron to Lake Erie; general rules. (a) Purpose....

  4. 33 CFR 162.132 - Connecting waters from Lake Huron to Lake Erie; communications rules.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; communications rules. 162.132 Section 162.132 Navigation and Navigable Waters COAST... NAVIGATION REGULATIONS § 162.132 Connecting waters from Lake Huron to Lake Erie; communications rules....

  5. 14 CFR 93.69 - Special requirements, Lake Campbell and Sixmile Lake Airports.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Special requirements, Lake Campbell and Sixmile Lake Airports. 93.69 Section 93.69 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Anchorage, Alaska, Terminal Area § 93.69 Special requirements, Lake Campbell and Sixmile Lake Airports....

  6. 33 CFR 162.134 - Connecting waters from Lake Huron to Lake Erie; traffic rules.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; traffic rules. 162.134 Section 162.134 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.134 Connecting waters from Lake Huron to Lake Erie; traffic rules. (a) Detroit River....

  7. Energy density of lake whitefish Coregonus clupeaformis in Lakes Huron and Michigan

    USGS Publications Warehouse

    Pothoven, S.A.; Nalepa, T.F.; Madenjian, C.P.; Rediske, R.R.; Schneeberger, P.J.; He, J.X.

    2006-01-01

    We collected lake whitefish Coregonus clupeaformis off Alpena and Tawas City, Michigan, USA in Lake Huron and off Muskegon, Michigan USA in Lake Michigan during 2002–2004. We determined energy density and percent dry weight for lake whitefish from both lakes and lipid content for Lake Michigan fish. Energy density increased with increasing fish weight up to 800 g, and then remained relatively constant with further increases in fish weight. Energy density, adjusted for weight, was lower in Lake Huron than in Lake Michigan for both small (≤800 g) and large fish (>800 g). Energy density did not differ seasonally for small or large lake whitefish or between adult male and female fish. Energy density was strongly correlated with percent dry weight and percent lipid content. Based on data from commercially caught lake whitefish, body condition was lower in Lake Huron than Lake Michigan during 1981–2003, indicating that the dissimilarity in body condition between the lakes could be long standing. Energy density and lipid content in 2002–2004 in Lake Michigan were lower than data for comparable sized fish collected in 1969–1971. Differences in energy density between lakes were attributed to variation in diet and prey energy content as well as factors that affect feeding rates such as lake whitefish density and prey abundance.

  8. 33 CFR 162.130 - Connecting waters from Lake Huron to Lake Erie; general rules.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Connecting waters from Lake Huron to Lake Erie; general rules. 162.130 Section 162.130 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.130 Connecting waters from Lake Huron to Lake Erie; general rules. (a) Purpose....

  9. 33 CFR 162.132 - Connecting waters from Lake Huron to Lake Erie; communications rules.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Connecting waters from Lake Huron to Lake Erie; communications rules. 162.132 Section 162.132 Navigation and Navigable Waters COAST... NAVIGATION REGULATIONS § 162.132 Connecting waters from Lake Huron to Lake Erie; communications rules....

  10. 14 CFR 93.69 - Special requirements, Lake Campbell and Sixmile Lake Airports.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Special requirements, Lake Campbell and Sixmile Lake Airports. 93.69 Section 93.69 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Anchorage, Alaska, Terminal Area § 93.69 Special requirements, Lake Campbell and Sixmile Lake Airports....

  11. 33 CFR 162.140 - Connecting waters from Lake Huron to Lake Erie; miscellaneous rules.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Connecting waters from Lake Huron to Lake Erie; miscellaneous rules. 162.140 Section 162.140 Navigation and Navigable Waters COAST... NAVIGATION REGULATIONS § 162.140 Connecting waters from Lake Huron to Lake Erie; miscellaneous rules....

  12. Competition between larval lake herring (Coregonus artedi) and lake whitefish (Coregonus clupeaformis) for zooplankton

    USGS Publications Warehouse

    Davis, Bruce M.; Todd, Thomas N.

    1998-01-01

    Diet and growth of larval lake herring (Coregonus artedi) and lake whitefish (Coregonus clupeaformis) were compared in mesocosm experiments in a small mesotrophic lake in southeastern Michigan. Fish were sampled from single-species and mixed assemblages in 2-m3 cages for 8 weeks during April and May. Both species initially ate mostly cyclopoid copepodites and small cladocerans (Bosmia spp.). Schoener's index of diet overlap showed considerable overlap (70-90%). Lake whitefish ate Daphnia spp. and adult copepods about 2 weeks earlier than did lake herring, perhaps related to their larger mean mouth gape. Lake whitefish were consistently larger than lake herring until the eighth week, especially in the sympatric treatments. Lake whitefish appeared to have a negative effect on the growth of lake herring, as lake herring in mixed-species treatments were smaller and weighed less than lake herring reared in single-species treatments. The diet similarities of lake whitefish and lake herring larvae could make them competitors for food in the Great Lakes. The greater initial size of lake whitefish could allow them to eat larger prey earlier and thereby limit availability of these prey to lake herring at a crucial period of development.

  13. 33 CFR 110.127 - Lake Mohave and Lake Mead, Nevada and Arizona.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Lake Mohave and Lake Mead, Nevada and Arizona. 110.127 Section 110.127 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.127 Lake Mohave and Lake Mead, Nevada and Arizona. (a) Willow...

  14. 78 FR 17869 - Safety Zone; Desert Storm Shootout; Lake Havasu, Lake Havasu City, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-25

    ... FR Federal Register NPRM Notice of Proposed Rulemaking A. Regulatory History and Information The... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Desert Storm Shootout; Lake Havasu, Lake... establishing a temporary safety zone on the navigable waters of the Colorado River in Lake Havasu, Lake...

  15. Glacial-Lake Outburst Erosion of the Grand Valley, Michigan, and Impacts on Glacial Lakes in the Lake Michigan Basin

    NASA Astrophysics Data System (ADS)

    Kehew, Alan E.

    1993-01-01

    Geomorphic and sedimentologic evidence in the Grand Valley, which drained the retreating Saginaw Lobe of the Laurentide Ice Sheet and later acted as a spillway between lakes in the Huron and Erie basins and in the Michigan basin, suggests that at least one drainage event from glacial Lake Saginaw to glacial Lake Chicago was a catastrophic outburst that deeply incised the valley. Analysis of shoreline and outlet geomorphology at the Chicago outlet supports J H Bretz's hypothesis of episodic incision and lake-level change. Shoreline features of each lake level converge to separate outlet sills that decrease in elevation from the oldest to youngest lake phases. This evidence, coupled with the presence of boulder lags and other features consistent with outburst origin, suggests that the outlets were deepened by catastrophic outbursts at least twice. The first incision event is correlated with a linked series of floods that progressed from Huron and Erie basin lakes to glacial Lake Saginaw to glacial Lake Chicago and then to the Mississippi. The second downcutting event occurred after the Two Rivers Advance of the Lake Michigan Lobe. Outbursts from the eastern outlets of glacial Lake Agassiz to glacial Lake Algonquin are a possible cause for this period of downcutting at the Chicago outlets.

  16. Episodic acidification of Adirondack lakes during snowmelt

    SciTech Connect

    Schaefer, D.A.; Driscoll, C.T.; Van Dreason, R.; Yatsko, C.P.

    1990-07-01

    Maximum values of acid neutralizing capacity (ANC) in Adirondack, New York lake outlets generally occur during summer and autumn. During spring snowmelt, transport of acidic water through acid-sensitive watersheds causes depression of upper lake water ANC. In some systems lake outlet ANC reaches negative values. The authors examined outlet water chemistry from II Adirondack lakes during 1986 and 1987 snowmelts. In these lakes, SO concentrations were diluted during snowmelt and did not depress ANC. For lakes with high baseline ANC values, springtime ANC depressions were primarily accompanied by basic cation dilution. For lakes with low baseline ANC, No increases dominated ANC depressions. Lakes with intermediate baseline ANC were affected by both processes and exhibited larger ANC depressions. Ammonium dilution only affected wetland systems. A model predicting a linear relationship between outlet water ANC minima and autumn ANC was inappropriate. To assess watershed response to episodic acidification, hydrologic flow paths must be considered. (Copyright (c) 1990 by the American Geophysical Union.)

  17. Recent Warming of Lake Kivu

    PubMed Central

    Katsev, Sergei; Aaberg, Arthur A.; Crowe, Sean A.; Hecky, Robert E.

    2014-01-01

    Lake Kivu in East Africa has gained notoriety for its prodigious amounts of dissolved methane and dangers of limnic eruption. Being meromictic, it is also expected to accumulate heat due to rising regional air temperatures. To investigate the warming trend and distinguish between atmospheric and geothermal heating sources, we compiled historical temperature data, performed measurements with logging instruments, and simulated heat propagation. We also performed isotopic analyses of water from the lake's main basin and isolated Kabuno Bay. The results reveal that the lake surface is warming at the rate of 0.12°C per decade, which matches the warming rates in other East African lakes. Temperatures increase throughout the entire water column. Though warming is strongest near the surface, warming rates in the deep waters cannot be accounted for solely by propagation of atmospheric heat at presently assumed rates of vertical mixing. Unless the transport rates are significantly higher than presently believed, this indicates significant contributions from subterranean heat sources. Temperature time series in the deep monimolimnion suggest evidence of convection. The progressive deepening of the depth of temperature minimum in the water column is expected to accelerate the warming in deeper waters. The warming trend, however, is unlikely to strongly affect the physical stability of the lake, which depends primarily on salinity gradient. PMID:25295730

  18. Neoichnology at lake margins: Implications for paleo-lake systems

    NASA Astrophysics Data System (ADS)

    Hamer, Jessica M. M.; Sheldon, Nathan D.

    2010-07-01

    Neoichnological studies provide significant information that can aid in the interpretation of ancient ichnological assemblages. Here we examine, for the first time, the pattern in both vertebrate and invertebrate trace distribution and abundance that can be seen in two geographically separate, but broadly analogous, contemporary semi-arid climate lake margin settings in an effort to describe taphonomic processes relevant to paleo-lake systems. Lake margin to supralittoral zone transects were made at Ruby Reservoir, Montana (USA) and La Sotonera, Spain and vegetation cover, trace cover %, trace diversity, and substrate characteristics were recorded. Similar patterns in trace distribution were seen through the eulittoral to supralittoral zones, with the majority of traces identified within a single transect present at both sites. However, a few traces attributed to larger organisms were found to be unique to each and in some instances, could to be assigned to a specific trace maker. The eulittoral zone was considered to have characteristics attributable to the Scoyenia ichnofacies, however, analysis of the supralittoral zone shows some characteristics of both the Coprinisphaera and the Mermia ichnofacies. In addition, a transitional zone between a Scoyenia-like ichnofacies and a fully terrestrial assemblage was found, which may enable continental ichnofacies to be further refined for application to paleo-lake systems. Study of the distribution of traces with distance along the transects also suggests taphonomic biases against the preservation of certain types of traces (e.g., avian) due to seasonal fluctuations of the lake level and the subsequent reduced preservation potential for lake-proximal traces.

  19. Lake evaporation estimates in tropical Africa (Lake Ziway, Ethiopia)

    NASA Astrophysics Data System (ADS)

    Vallet-Coulomb, Christine; Legesse, Dagnachew; Gasse, Françoise; Travi, Yves; Chernet, Tesfaye

    2001-05-01

    Estimates of evaporation from an open shallow lake in tropical Africa (Lake Ziway, Main Ethiopian Rift) are made by using monthly hydrometeorological data available for the past three decades. On the one hand, annual average estimates are inferred from three climatic approaches, which can be applied in areas with limited meteorological data. The lake energy balance yields an evaporation rate of 1780 mm yr -1, assuming a Bowen ratio of 0.15 (that of Lake Victoria). The Penman method gives an annual evaporation rate of 1870 mm. The complementary relationship lake evaporation model (CRLE) applied on monthly averaged values of air temperature, air humidity and sunshine duration gives 1730 mm yr -1. The sensitivity of each method to changes in input variables is analyzed in order to test the stability of the resulting estimates. This helps discuss uncertainties and possible inter-annual variations of the evaporation rate. On the other hand, the monthly lake level records together with precipitation and river discharge data between 1969 and 1990, allow us to estimate the water balance, providing an annual rate of 1937 mm for the combined evaporation and groundwater losses. The chloride budget is used to discriminate the groundwater from the evaporation loss. It gives us an annual evaporation rate of 1740 mm and a corresponding groundwater loss of 200 mm yr -1. The groundwater loss estimate is of the same order of magnitude as the surface outflow, but the associated error in the former is significant because the result is sensitive to the poorly known chloride content of river inflows. Our results can be used to forecast the impact of increased water consumption in the basin.

  20. Periodic floods from glacial Lake Missoula into the Sanpoil arm of glacial Lake Columbia, northeastern Washington

    NASA Astrophysics Data System (ADS)

    Atwater, Brian F.

    1984-08-01

    At least 15 floods ascended the Sanpoil arm of glacial Lake Columbia during a single glaciation. Varves between 14 of the flood beds indicate one backflooding every 35 to 55 yr. This regularity suggests that the floods came from an ice-dammed lake that was self-dumping. Probably the self-dumping lake was glacial Lake Missoula, Montana, because the floods accord with inferred emptyings of that lake in frequency and number, apparently entered Lake Columbia from the east, and produced beds resembling backflood deposits of Lake Missoula floods in southern Washington.

  1. Estimating the volume of Alpine glacial lakes

    NASA Astrophysics Data System (ADS)

    Cook, S. J.; Quincey, D. J.

    2015-12-01

    Supraglacial, moraine-dammed and ice-dammed lakes represent a potential glacial lake outburst flood (GLOF) threat to downstream communities in many mountain regions. This has motivated the development of empirical relationships to predict lake volume given a measurement of lake surface area obtained from satellite imagery. Such relationships are based on the notion that lake depth, area and volume scale predictably. We critically evaluate the performance of these existing empirical relationships by examining a global database of glacial lake depths, areas and volumes. Results show that lake area and depth are not always well correlated (r2 = 0.38) and that although lake volume and area are well correlated (r2 = 0.91), and indeed are auto-correlated, there are distinct outliers in the data set. These outliers represent situations where it may not be appropriate to apply existing empirical relationships to predict lake volume and include growing supraglacial lakes, glaciers that recede into basins with complex overdeepened morphologies or that have been deepened by intense erosion and lakes formed where glaciers advance across and block a main trunk valley. We use the compiled data set to develop a conceptual model of how the volumes of supraglacial ponds and lakes, moraine-dammed lakes and ice-dammed lakes should be expected to evolve with increasing area. Although a large amount of bathymetric data exist for moraine-dammed and ice-dammed lakes, we suggest that further measurements of growing supraglacial ponds and lakes are needed to better understand their development.

  2. Bathythermal habitat use by strains of Great Lakes- and Finger Lakes-origin lake trout in Lake Huron after a change in prey fish abundance and composition

    USGS Publications Warehouse

    Bergstedt, Roger A.; Argyle, Ray L.; Krueger, Charles C.; Taylor, William W.

    2012-01-01

    A study conducted in Lake Huron during October 1998–June 2001 found that strains of Great Lakes-origin (GLO) lake trout Salvelinus namaycush occupied significantly higher temperatures than did Finger Lakes-origin (FLO; New York) lake trout based on data from archival (or data storage) telemetry tags that recorded only temperature. During 2002 and 2003, we implanted archival tags that recorded depth as well as temperature in GLO and FLO lake trout in Lake Huron. Data subsequently recorded by those tags spanned 2002–2005. Based on those data, we examined whether temperatures and depths occupied by GLO and FLO lake trout differed during 2002–2005. Temperatures occupied during those years were also compared with occupied temperatures reported for 1998–2001, before a substantial decline in prey fish biomass. Temperatures occupied by GLO lake trout were again significantly higher than those occupied by FLO lake trout. This result supports the conclusion of the previous study. The GLO lake trout also occupied significantly shallower depths than FLO lake trout. In 2002–2005, both GLO and FLO lake trout occupied significantly lower temperatures than they did in 1998–2001. Aside from the sharp decline in prey fish biomass between study periods, the formerly abundant pelagic alewife Alosa pseudoharengus virtually disappeared and the demersal round goby Neogobius melanostomus invaded the lake and became locally abundant. The lower temperatures occupied by lake trout in Lake Huron during 2002–2005 may be attributable to changes in the composition of the prey fish community, food scarcity (i.e., a retreat to cooler water could increase conversion efficiency), or both.

  3. Monitoring change in Great Salt Lake

    USGS Publications Warehouse

    Naftz, David L.; Angeroth, Cory E.; Freeman, Michael L.; Rowland, Ryan C.; Carling, Gregory

    2013-01-01

    Despite the ecological and economic importance of Great Salt Lake, only limited water quality monitoring has occurred historically. To change this, new monitoring stations and networks—gauges of lake level height and rate of inflow, moored buoys, and multiple lake-bottom sensors—will provide important information that can be used to make informed decisions regarding future management of the Great Salt Lake ecosystem.

  4. Teshekpuk Lake, Alaska

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This ASTER image of Teshekpuk Lake on Alaska's North Slope, within the National Petroleum Reserve, was acquired on August 15, 2000. It covers an area of 58.7 x 89.9 km, and is centered near 70.4 degrees north latitude, 153 degrees west longitude.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

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

    Size: 58.7 by 89.9 kilometers (36.4 by 55.7 miles) Location: 70.4 degrees North latitude, 153 degrees West longitude Orientation: North at top Image Data: ASTER Bands 3, 2, and 1 Original Data Resolution: ASTER 30 meters (98.4 feet) Dates Acquired: August 15, 2000

  5. Ancient lakes on Mars?

    NASA Technical Reports Server (NTRS)

    Goldspiel, J. M.; Squyres, S. W.

    1989-01-01

    The valley systems in Mars' ancient cratered terrain provide strong evidence for a warmer and wetter climate very early in planetary history. The valley systems in some instances debouch into closed depressions that could have acted as local ponding basins for the flow. A survey of the Martian equatorial region shows that numerous local depressions at the confluence of valley systems exist. These depressions (approximately 100 km) typically are characterized by many valleys flowing into them and few or none flowing out. If ponding did take place, these basin would have contained lakes for some period during Mars' early warmer epoch. Although the collection basins are numerous, location of ones that have not suffered significant subsequent geologic modification is difficult. Some morphologic features suggest that volcanic lavas may have filled them subsequent to any early fluvial activity. Two detailed maps of valley systems and local ponding basins in USGC 1:2,000,000 subquadrangles were completed and a third is in progress. The completed regions are in Mare Tyrrhenum (MC-22 SW) and Margarifter Sinus (MC-19 SE), and the region in progress is in Iapygia (MC-21 NW). On the maps, the valley systems and interpreted margins of ponding basins are indicated. The depressions are of interest for two reasons. First, the depressions were surely the sites in which the materials eroded from the valleys were deposited. Such sediments could preserve important information about the physical conditions at the time of deposition. Second, the sediments could preserve evidence of water-atmosphere interactions during the early period of the Martian climate. Atmospheric carbon dioxide would dissolve in water, and solid carbonate minerals would tend to precipitate out to form carbonate sedimentary deposits. Formation of carbonates in this manner might account for some of the CO2 lost from the early more dense atmosphere.

  6. First evidence of successful natural reproduction by planted lake trout in Lake Huron

    USGS Publications Warehouse

    Nester, Robert T.; Poe, Thomas P.

    1984-01-01

    Twenty-two lake trout (Salvelinus namaycush) swim-up fry, 24-27 mm long, were captured with emergent fry traps and a tow net in northwestern Lake Huron on a small nearshore reef off Alpena, Michigan, between May 10 and June 1, 1982. These catches represent the first evidence of successful production of swim-up fry by planted, hatchery-reared lake trout in Lake Huron since the lake trout rehabilitation program began in 1973.

  7. EPISODIC ACIDIFICATION OF ADIRONDACK LAKES DURING SNOWMELT

    EPA Science Inventory

    Maximum values of acid neutralizing capacity (ANC) in Adirondack, New York lake outlets generally occur during summer and autumn. During spring snowmelt, transport of acidic water through acid-sensitive watersheds causes depression of upper lake water ANC. n some systems lake out...

  8. 27 CFR 9.177 - Alexandria Lakes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... and Lake Darling at benchmark (BM) 1366, which is an unmarked bridge on County Road 11, known as the... road known as County Road 62; then (5) North along County Road 62 on to the Lake Miltona, East, Minn...; then (10) South along County Road 34 until the point where County Road 34 runs parallel to Lake...

  9. 27 CFR 9.128 - Seneca Lake.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Cross Road, which changes to Cretsley Road, to its intersection with Mud Lake Road (County Road 23) on... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Seneca Lake. 9.128 Section... Lake. (a) Name. The name of the viticultural area described in this section is “Seneca Lake”....

  10. 27 CFR 9.146 - Lake Wisconsin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., Columbia County, where Spring Creek enters Lake Wisconsin; (2) From the point of beginning, follow the... Bay, Sauk County, where the Wisconsin River becomes Lake Wisconsin again on the map; (4) Then... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Lake Wisconsin....

  11. 27 CFR 9.177 - Alexandria Lakes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... and Lake Darling at benchmark (BM) 1366, which is an unmarked bridge on County Road 11, known as the... road known as County Road 62; then (5) North along County Road 62 on to the Lake Miltona, East, Minn...; then (10) South along County Road 34 until the point where County Road 34 runs parallel to Lake...

  12. 27 CFR 9.177 - Alexandria Lakes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... and Lake Darling at benchmark (BM) 1366, which is an unmarked bridge on County Road 11, known as the... road known as County Road 62; then (5) North along County Road 62 on to the Lake Miltona, East, Minn...; then (10) South along County Road 34 until the point where County Road 34 runs parallel to Lake...

  13. 27 CFR 9.128 - Seneca Lake.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Cross Road, which changes to Cretsley Road, to its intersection with Mud Lake Road (County Road 23) on... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Seneca Lake. 9.128 Section... Lake. (a) Name. The name of the viticultural area described in this section is “Seneca Lake”....

  14. 27 CFR 9.128 - Seneca Lake.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Cross Road, which changes to Cretsley Road, to its intersection with Mud Lake Road (County Road 23) on... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Seneca Lake. 9.128 Section... Lake. (a) Name. The name of the viticultural area described in this section is “Seneca Lake”....

  15. 27 CFR 9.146 - Lake Wisconsin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., Columbia County, where Spring Creek enters Lake Wisconsin; (2) From the point of beginning, follow the... Bay, Sauk County, where the Wisconsin River becomes Lake Wisconsin again on the map; (4) Then... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Lake Wisconsin....

  16. 27 CFR 9.177 - Alexandria Lakes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... and Lake Darling at benchmark (BM) 1366, which is an unmarked bridge on County Road 11, known as the... road known as County Road 62; then (5) North along County Road 62 on to the Lake Miltona, East, Minn...; then (10) South along County Road 34 until the point where County Road 34 runs parallel to Lake...

  17. 27 CFR 9.128 - Seneca Lake.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Cross Road, which changes to Cretsley Road, to its intersection with Mud Lake Road (County Road 23) on... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Seneca Lake. 9.128 Section... Lake. (a) Name. The name of the viticultural area described in this section is “Seneca Lake”....

  18. 27 CFR 9.177 - Alexandria Lakes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... and Lake Darling at benchmark (BM) 1366, which is an unmarked bridge on County Road 11, known as the... road known as County Road 62; then (5) North along County Road 62 on to the Lake Miltona, East, Minn...; then (10) South along County Road 34 until the point where County Road 34 runs parallel to Lake...

  19. 27 CFR 9.146 - Lake Wisconsin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., Columbia County, where Spring Creek enters Lake Wisconsin; (2) From the point of beginning, follow the... Bay, Sauk County, where the Wisconsin River becomes Lake Wisconsin again on the map; (4) Then... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Lake Wisconsin....

  20. 27 CFR 9.146 - Lake Wisconsin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., Columbia County, where Spring Creek enters Lake Wisconsin; (2) From the point of beginning, follow the... Bay, Sauk County, where the Wisconsin River becomes Lake Wisconsin again on the map; (4) Then... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Lake Wisconsin....

  1. 27 CFR 9.146 - Lake Wisconsin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., Columbia County, where Spring Creek enters Lake Wisconsin; (2) From the point of beginning, follow the... Bay, Sauk County, where the Wisconsin River becomes Lake Wisconsin again on the map; (4) Then... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Lake Wisconsin....

  2. 27 CFR 9.128 - Seneca Lake.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Cross Road, which changes to Cretsley Road, to its intersection with Mud Lake Road (County Road 23) on... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Seneca Lake. 9.128 Section... Lake. (a) Name. The name of the viticultural area described in this section is “Seneca Lake”....

  3. 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)

  4. 27 CFR 9.83 - Lake Erie.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Lake Erie. 9.83 Section 9... TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.83 Lake Erie. (a) Name. The name of the viticultural area described in this section is “Lake Erie.” (b) Approved...

  5. 33 CFR 117.797 - Lake Champlain.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lake Champlain. 117.797 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.797 Lake Champlain. (a) The drawspan... United States. (b) The draw of the US2 Bridge, mile 91.8, over Lake Champlain, between South Hero...

  6. 33 CFR 117.993 - Lake Champlain.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lake Champlain. 117.993 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Vermont § 117.993 Lake Champlain. (a) The drawspan for... vessels of the United States. (b) The draw of the US2 Bridge, mile 91.8, over Lake Champlain,...

  7. 36 CFR 13.1208 - Lake Camp.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Lake Camp. 13.1208 Section 13... § 13.1208 Lake Camp. Leaving a boat, trailer, or vehicle unattended for more than 72 hours at the facilities associated with the Lake Camp launching ramp is prohibited without authorization from...

  8. Great Lakes Education Booklet, 1990-1991.

    ERIC Educational Resources Information Center

    Michigan State Dept. of Natural Resources, Lansing.

    This booklet integrates science, history, and environmental education to help students acquire a basic understanding of the importance of the Great Lakes located in the United States. The packet also contains a Great Lakes Basin resource map and a sand dune poster. These materials introduce students to a brief history of the lakes, the diversity…

  9. A reactive nitrogen budget for Lake Michigan

    EPA Science Inventory

    The reactive nitrogen budget for Lake Michigan was reviewed and updated, making use of recent estimates of watershed and atmospheric nitrogen loads. The updated total N load to Lake Michigan was approximately double the previous estimate from the Lake Michigan Mass Balance study ...

  10. 36 CFR 13.1208 - Lake Camp.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Lake Camp. 13.1208 Section 13... § 13.1208 Lake Camp. Leaving a boat, trailer, or vehicle unattended for more than 72 hours at the facilities associated with the Lake Camp launching ramp is prohibited without authorization from...

  11. 33 CFR 117.993 - Lake Champlain.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Lake Champlain. 117.993 Section... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Vermont § 117.993 Lake Champlain. (a) The drawspan for... vessels of the United States. (b) The draw of the US2 Bridge, mile 91.8, over Lake Champlain,...

  12. 27 CFR 9.83 - Lake Erie.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Lake Erie. 9.83 Section 9... TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.83 Lake Erie. (a) Name. The name of the viticultural area described in this section is “Lake Erie.” (b) Approved...

  13. 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.

  14. Lake sensitivity to acid rain

    SciTech Connect

    Shurkin, J.; Goldstein, R.

    1985-06-01

    Research in the Adirondacks suggests that watershed dynamics are the key to a lake's vulnerability to acidification. The Electric Power Research Institute's Integrated Lake-Watershed Acidification Study (ILWAS) produced a computer model that successfully integrated the physical and chemical factors that determine these dynamics. The research required an unprecedented level of awareness of how watersheds work and how rain, soil, forests, and rocks interact. One outcome of the field and laboratory studies was the finding that some soils act as buffers, taking certain ions out of the water, while some added ions. While the ability of the watershed as a whole to neutralize acid is the main determinant of a lake's vulnerability, seasonal changes demonstrate that time is a factor. The model is in demand to test water in other locations and to explore buffering agents. 2 figures.

  15. Lake Volume Monitoring from Space

    NASA Astrophysics Data System (ADS)

    Crétaux, J.-F.; Abarca-del-Río, R.; Bergé-Nguyen, M.; Arsen, A.; Drolon, V.; Clos, G.; Maisongrande, P.

    2016-03-01

    Lakes are integrators of environmental change occurring at both the regional and global scale. They present a wide range of behavior on a variety of timescales (cyclic and secular) depending on their morphology and climate conditions. Lakes play a crucial role in retaining and stocking water, and because of the significant global environmental changes occurring at several anthropocentric levels, the necessity to monitor all morphodynamic characteristics [e.g., water level, surface (water contour) and volume] has increased substantially. Satellite altimetry and imagery are now widely used together to calculate lake and reservoir water storage changes worldwide. However, strategies and algorithms to calculate these characteristics are not straightforward, and specific approaches need to be developed. We present a review of some of these methodologies by using lakes over the Tibetan Plateau to illustrate some critical aspects and issues (technical and scientific) linked to the observation of climate change impact on surface waters from remote sensing data. Many authors have measured water variation using the limited remote sensing measurements available over short time periods, even though the time series are probably too short to directly link these results with climate change. Indeed, there are many processes and factors, like the influence of lake morphology, that are beyond observation and are still uncertain. The time response for lakes to reach a new state of equilibrium is a key aspect that is often neglected in current literature. Observations over a long period of time, including maintaining a constellation of comprehensive and complementary satellite missions with service continuity over decades, are therefore necessary especially when the ground gauge network is too limited. In addition, the design of future satellite missions with new instrumental concepts (e.g., SAR, SARin, Ka band altimetry, Ka interferometry) will also be suitable for complete

  16. The High-Lakes Project

    NASA Astrophysics Data System (ADS)

    Cabrol, Nathalie A.; Grin, Edmond A.; Chong, Guillermo; Minkley, Edwin; Hock, Andrew N.; Yu, Youngseob; Bebout, Leslie; Fleming, Erich; Häder, Donat P.; Demergasso, Cecilia; Gibson, John; Escudero, Lorena; Dorador, Cristina; Lim, Darlene; Woosley, Clayton; Morris, Robert L.; Tambley, Cristian; Gaete, Victor; Galvez, Matthieu E.; Smith, Eric; Uskin-Peate, Ingrid; Salazar, Carlos; Dawidowicz, G.; Majerowicz, J.

    2009-06-01

    The High Lakes Project is a multidisciplinary astrobiological investigation studying high-altitude lakes between 4200 m and 6000 m elevation in the Central Andes of Bolivia and Chile. Its primary objective is to understand the impact of increased environmental stress on the modification of lake habitability potential during rapid climate change as an analogy to early Mars. Their unique geophysical environment and mostly uncharted ecosystems have added new objectives to the project, including the assessment of the impact of low-ozone/high solar irradiance in nonpolar aquatic environments, the documentation of poorly known ecosystems, and the quantification of the impact of climate change on lake environment and ecosystem. Data from 2003 to 2007 show that UV flux is 165% that of sea level with maximum averaged UVB reaching 4 W/m2. Short UV wavelengths (260-270 nm) were recorded and peaked at 14.6 mW/m2. High solar irradiance occurs in an atmosphere permanently depleted in ozone falling below ozone hole definition for 33-36 days and between 30 and 35% depletion the rest of the year. The impact of strong UVB and UV erythemally weighted daily dose on life is compounded by broad daily temperature variations with sudden and sharp fluctuations. Lake habitat chemistry is highly dynamical with notable changes in yearly ion concentrations and pH resulting from low and variable yearly precipitation. The year-round combination of environmental variables define these lakes as end-members. In such an environment, they host ecosystems that include a significant fraction of previously undescribed species of zooplankton, cyanobacterial, and bacterial populations.

  17. Fertilization of eggs of Lake Michigan lake trout Salvelinus namaycush in lake water: Effect of PCBs (Aroclor 1254)

    USGS Publications Warehouse

    Foster, N.R.; Berlin, W.H.

    1997-01-01

    Various studies indicate that PCBs appear to have an adverse effect on the viability of fertilized eggs and subsequent early life stages of lake trout and related species. Our tests detected no impairment of fertilization of lake trout eggs in PCB-dosed lake water. The concentration of PCBs in the fertilization medium that we used was more than 20 times as high as estimated ambient levels in southeastern Lake Michigan and it appears unlikley that ambient levels of PCBs in the water at fertilization would contribute significantly to the apparent widespread reproductive failure of lake trout there.

  18. Lava Lakes in Io's Paterae

    NASA Astrophysics Data System (ADS)

    Radebaugh, J.; McEwen, A. S.; Milazzo, M.; Davies, A. G.; Keszthelyi, L. P.; Geissler, P.

    2002-05-01

    New Galileo images and Galileo and Cassini temperature data lend credence to previous proposals that some of the paterae on Io contain lava lakes, similar in some ways to those observed on Earth. Galileo's October 2001 I32 flyby produced spectacular new high resolution observations of Io's paterae, their margins, and floors. Images reveal where lavas have filled Emakong Patera and overtopped its margins. Landslides from the peaks of Tohil Mons are not present on the adjacent floor of a dark patera, perhaps because they have slumped into a molten lava pit. Dark lavas have filled and drained back from colorful Tupan Patera, leaving a ring of material on its walls. This patera also shows evidence of interaction between molten sulfur and silicate lavas, a relationship observed at the terrestrial Poas Volcano (Francis et al., 1980, Nature 283, 754-756; Oppenheimer and Stevenson, 1990, La Recherche 21,1088-1090). The extremely uniformly dark materials in many other paterae could also be lava lakes. Pele Volcano on Io, in particular, has previously been considered a lava lake based on several characteristics (Davies et al., 2001, JGR 106,33,079-33,103). Recent analyses of eclipse images of Pele from Cassini reveal average temperatures of 1375 K, with variations on short (~10 minute) timescales, consistent with active fountaining in a lava lake. Similar oscillations around high temperatures over these time scales are seen in terrestrial lava lakes, such as at Kupaianaha (Flynn et al., GRL, 19,6461-6476, 1993) and Erta Ale (Bessard, Caillet and others, in progress). Nightside high resolution (60 m/pixel) images from Galileo I32 reveal a region of overturning and convection, with some areas reaching in excess of 1800 K, verifying very high-temperature components identified in high-resolution NIMS data (Lopes et al., 2001, JGR, 106, 33,053-33,078). This region is ringed with small hotspots, comparable to locations of breakup and fountaining at the margins of many terrestrial

  19. Remote sensing and lake eutrophication

    NASA Technical Reports Server (NTRS)

    Wrigley, R. C.; Horne, A. J.

    1974-01-01

    An infrared photograph of part of Clear Lake, Cal., shows complex patterns of blue-green algal blooms which were not observed by conventional limnological techniques. Repeated observations of patterns such as these can be used to chart the surface movement of these buoyant algae and can also be used to help control algal scums in eutrophic lakes. Although it is believed that most of the observed patterns resulted from Aphanizomenon (a few were also observed which resulted from suspended sediment), spectral signatures of the algal patterns varied.

  20. Crustal structure between Lake Mead, Nevada, and Mono Lake, California

    USGS Publications Warehouse

    Johnson, Lane R.

    1964-01-01

    Interpretation of a reversed seismic-refraction profile between Lake Mead, Nevada, and Mono Lake, California, indicates velocities of 6.15 km/sec for the upper layer of the crust, 7.10 km/sec for an intermediate layer, and 7.80 km/sec for the uppermost mantle. Phases interpreted to be reflections from the top of the intermediate layer and the Mohorovicic discontinuity were used with the refraction data to calculate depths. The depth to the Moho increases from about 30 km near Lake Mead to about 40 km near Mono Lake. Variations in arrival times provide evidence for fairly sharp flexures in the Moho. Offsets in the Moho of 4 km at one point and 2 1/2 km at another correspond to large faults at the surface, and it is suggested that fracture zones in the upper crust may displace the Moho and extend into the upper mantle. The phase P appears to be an extension of the reflection from the top of the intermediate layer beyond the critical angle. Bouguer gravity, computed for the seismic model of the crust, is in good agreement with the measured Bouguer gravity. Thus a model of the crustal structure is presented which is consistent with three semi-independent sources of geophysical data: seismic-refraction, seismic-reflection, and gravity.