Site-specific sediment responses to climate change during the last 140 years in three varved lakes in Northern Poland

Accurate dating and unambiguous chronological correlation using cryptotephras provide a powerful tool to compare the varved sediment records of the lakes G??boczek (JG), Czechowskie (JC) and Jelonek (JEL) (north-central Poland). For the last 140 years, micro-facies analyses and µ-XRF element scanning at seasonal resolution, as well as bulk elemental analyses (organic matter, carbonate) at sub-decadal to decadal resolution, were conducted for all three lakes records. All lakes are located in a region with low population density, and therefore, anthropogenic influences are negligible or only minor. The varve chronologies have been established independently for each record and were synchronized with the Askja AD 1875 cryptotephra. Comparison with monthly temperature data since 1870 and daily temperature data since 1951 revealed different responses of lake deposition to recent climate change. Varves are well preserved over the entire 140 years only at JG, while in the JC record two faintly varved intervals are intercalated and in the JEL record two non-varved intervals occur at the base and top of the profiles. These differences likely are due to variations in lake characteristics and their influence on lake-internal responses. JG is the smallest and best wind-sheltered lake, which favours varve preservation. JC?s attenuated sediment responses can likely be linked to lake productivity changes with respect to climate warming. JEL is lacking a direct sedimentological response to the observed temperature increase, which can be linked to lake size and water depth superimposing regional climate changes. Climate changes at the demise of the ?Little Ice Age? around 1900 and the recent warming since the 1980s are expressed in sediment proxies in the lakes with different response times and amplitudes. This detailed comparison study on three nearby lakes demonstrates the influence of local parameters such as lake and catchment size and water depth superimposed on more regional climate-driven changes

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