Effects of thermodynamical processes on radiocesium behavior in lake tapeliai / Termodinaminių procesų įtaka radiocezio elgsenai tapelių ežere

The article presents the results of the integrated study of radiocesium behavior in Lake Tapeliai using not only conventional data on radiocesium activity concentrations in lake water and sediments but also a complex data set on seasonal variations and vertical profiles of standard water variables. Radiocesium activity concentrations in lake water as well as the vertical structure of the water column considerably depend on the inflows of the colored waters from the swampy watershed of the lake enriched in radiocesium. The global fallouts are mainly responsible for radiocesium inventory in lake sediments, which reaches maximum in the upper part of the water column above the ~5.4-m depth. The maximum values of radiocesium inventories in lake sediments are consistent with the respective densities of its deposits in the nearest forest soils. The main process of sediment activation is the direct sorption of radiocesium onto the sediment surface. Sedimentation rates in the lake vary mainly in the range of 3.5–5 mm·a–1. Lake bottom feeding sources located mainly on the southern terrace as well as their related near-bottom flows reduce respective sedimentation and radiocesium inventories in the sediments. Santrauka Straipsnyje nagrinėjama radiocezio elgsena Tapelių ežere, naudojant ne tik radiocezio savitojo ir tūrinio aktyvumų duomenis, bet ir standartinius vertikaliuosius parametrus, tokius kaip temperatūra, elektros laidumai ir oksiduoto sluoksnio storis. Radiocezio aktyvumas ežero vandenyje priklauso nuo spalvoto pelkinio vandens, kuriame yra radiocezio, patekimo į ežerą. Radiocezio apkrova dugno nuosėdose yra didžiausia viršutinėje ežero dalyje, t. y. iki 5,4 m gylio. Sedimentacijos greitis svyruoja 3,5–5 mm·m–1. Ežero priedugniniai vandens šaltiniai daugiausia išsidėstę pietinėje ežero terasoje, jų srovės sumažina sedimentaciją ir radiocezio apkrovą dugno nuosėdose. Raktiniai žodžiai: dugno nuosėdos, ežeras, radiocezis, radiocezio apkrov

The Spectrality of Nuclear Catastrophe: The Case of Chernobyl

The paper is a presentation of our research focused on the ecological disaster caused by the explosion of the nuclear power plant reactor in Chernobyl in 1986, in terms of its social, cultural and artistic context. We apply the concepts of hyperobject (Morton) and hauntology (Derrida), and autoethnographic method (Adams, Jones, Ellis), in an attempt to reveal human and nonhuman agencies in the description of the catastrophe’s long-term cultural consequences. In the autoethnographic and investigative-artistic part of our research we analyse our interactive installation, Post-Apocalypsis (2015), but also historical facts and private narratives. The notion of hyperobject in connection with the autoethnographic methods and investigative-artistic part of our research serves to trace the process of displacing phenomena, facts and private narratives about the Chernobyl accident in the context of time and space. The concept of hauntology enabled us to go beyond the uncovering of recurring cultural, political, social micronarrations and fear about nuclear energy in Poland

Large and deep perialpine lakes: a paleolimnological perspective for the advance of ecosystem science

Large perialpine lakes represent important components of the Alpine landscape. Due to their piedmont location in the most densely populated regions of the Alps, they play a crucial socio-economic role as resource for drinking water, irrigation, industry, tourism, hydroelectric production, and biodiversity conservation. These uses expose perialpine lakes to multiple human pressure, while the extension of their catchment to the glacial Alpine range make them particularly exposed to the consequences of global warming. Limnological surveys outlined coherent responses by perialpine lakes to the massive nutrient enrichment during the 1950s-1970s, while recent development is rather heterogeneous. Past and ongoing paleolimnological studies confirmed the coherence of the lakes’ evolution within a secular perspective, but outlined individual trends as resulting from local management policies, lake morphology, and superimposed effects of climate change. A review of the paleolimnological literature published from 1975 to April 2017on perialpine lakes of different lake districts north and south of the Alps, was performed aiming at reviewing current knowledge of large and deep perialpine lakes due to sediment studies, and at summarizing how paleolimnological studies can contribute in defining past ecological status and in outlining lake sensitivity to current and future human impacts. This is particularly important when defining reference conditions, as inappropriate restoration targets might prove to become unachievable within the present context of global change. The review outlined an heterogeneous distribution of amount and topics of sediment studies among perialpine lake districts as well as knowledge gaps on the long term evolution of perialpine lakes