نتایج جستجو برای: long lake
تعداد نتایج: 813915 فیلتر نتایج به سال:
The (Lower) Lake of Zurich provides an ideal system for studying the long-term impact of environmental change on deep-water hypoxia because of its sensitivity to climatic forcing, its history of eutrophication and subsequent oligotrophication, and the quality and length of its data set. Based on 39 years (1972-2010) of measured profiles of temperature, oxygen concentration and phosphorus (P) co...
Recent proxy measurements reveal that subglacial lakes beneath modern ice sheets periodically store and release large volumes of water, providing an important but poorly understood influence on contemporary ice dynamics and mass balance. This is because direct observations of how lake drainage initiates and proceeds are lacking. Here we present physical evidence of the mechanism and geometry of...
Abstract Nuisance periphyton blooms are occurring in oligotrophic lakes worldwide, but few have documented changes biomass through monitoring. For decades has caused concern about Lake Tahoe’s nearshore water quality. To determine whether eulittoral increased Tahoe, measures of and dominant communities at 0.5 m below lake level been monitored regularly nine shoreline sites starting 1982, with u...
Exotic species invasions pose a pervasive threat to aquatic ecosystems worldwide, yet fundamental questions about the geographic origin and timing of invasions or introductions are frequently difficult to answer. We used natural chemical markers (Sr:Ca ratios) in otoliths to identify probable source and date of introduction of exotic lake trout (Salvelinus namaycush) into Yellowstone Lake, Wyom...
Aquatic prey species respond to predators with fast (developmental) and slow (selective) feedbacks. Natural selection is assumed to fashion details of induction and to modify baseline morphology, but only rarely do we catch the slower (multi-generation) process in action. Laboratory experiments with Bosmina detected predatormediated induction and estimated spine heritability (h2 5 0.2–0.5). Thi...
Lake Constance is among the largest lakes in central Europe and represents the most important drinking water reservoir in southwestern Germany. About 4 million people depend on this lake for their drinking water supply, and considerable efforts have been made to protect its high water quality (STABEL 1998). In addition to a drinking water supply, the lake is the receiving water body of numerous...
Both lake-calving Yakutat Glacier (337 km2), Alaska, USA, and its parent icefield (810 km2) are experiencing strong thinning, and under current climate conditions will eventually disappear. Comparison of digital elevation models shows that Yakutat Glacier thinned at area-averaged rates of 4.76 0.06mw.e. a (2000–07) and 3.66 0.03mw.e. a (2007–10). Simultaneously, adjacent Yakutat Icefield land-t...
Anthropogenic sources of chloride in a lake catchment, including road salt, fertilizer, and wastewater, can elevate the chloride concentration in freshwater lakes above background levels. Rising chloride concentrations can impact lake ecology and ecosystem services such as fisheries and the use of lakes as drinking water sources. To analyze the spatial extent and magnitude of increasing chlorid...
SO2 emission rates from Erebus volcano show periodicity, which directly relates to lava lake convection and magma and conduit processes. Mt. Erebus is a 3794 m stratovolcano with a persistently degassing convecting, phonolite lava lake. Lava lake SO2 emission rates were collected from 1992 to 2003 using the correlation spectrometer (COSPEC) and in 2003 and 2005 using a miniature ultra-violet di...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید