OSL dating of Middle Weichselian age shallow basin sediments in Western Latvia, Eastern Baltic
Abstract This paper presents the results of the first attempt to date the Quaternary sediments of western Latvia in the southeast Baltic region, using luminescence. The analyses have been carried out on sandy sediments of the Jurkalne Formation that are located between upper and lower Scandinavian sourced tills. Previous publications on the origin of the Quaternary sediments in the region are reviewed and it is found that there are a wide range of explanations for their processes of formation and their age of formation. It is concluded that although the sandy sediments were deposited in freshwater environment although they contain both marine and freshwater fauna and flora, a property that …
Pleistocene age paleo-groundwater inferred from water-stable isotope values in the central part of the Baltic Artesian Basin.
A new data set of δ(2)H and δ(18)O in the groundwater from the central part of the Baltic Artesian Basin is presented. The hydrogeological section is subdivided into stagnation, slow exchange and active exchange zones. Na-Ca-Cl brine found at the deepest part - the stagnation zone - is characterized by δ(18)O values above -5 ‰ and δ(2)H values approaching -40 ‰ with respect to Vienna Standard Mean Ocean Water. The slow exchange zone where waters of mostly intermediate salinity reside is characterized by δ(18)O values around -11.7 ‰ and δ(2)H values around -85.3 ‰. Mean δ(18)O and δ(2)H values of the fresh groundwater in the active water exchange zone are -11.1 and -79.9 ‰, respectively. Cha…
Subglacial bed deformation and dynamics of the Apriķi glacial tongue, W Latvia
Saks, T., Kalvans, A. & Zelcs, V. 2012 (January): Subglacial bed deformation and dynamics of the Apriķi glacial tongue, W Latvia. Boreas, Vol. 41, pp. 124–140. 10.1111/j.1502-3885.2011.00222.x. ISSN 0300-9483. We evaluate the glacial dynamics and subglacial processes of the Apriķi glacial tongue in western Latvia during the Northern Lithuanian (Linkuva) oscillation of the last Scandinavian glaciation. The spatial arrangement of glacial bedforms and deformation structures are used to reconstruct the ice dynamics in the study area. The relationship between geological structures at the glacier bed and the spatial distribution of drumlins and glacigenic diapirs, on the one hand, and the permeab…
Twenty-three unsolved problems in hydrology (UPH) – a community perspective
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Water stable isotope data set in temperate, lowland catchment, two years of monthly observations, River Salaca, Latvia
Highlights • Two years of monthly water stable isotope ratios from temperate lowland catchment. • Hourly water table, temperature and electrical conductivity monitoring. • Distinct isotope ratios for raised bog, groundwater and rivers.
Twenty-three unsolved problems in hydrology (UPH) – a community perspective
This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused on the process-…
A δ18O isoscape for the shallow groundwater in the Baltic Artesian Basin
The study presents a shallow groundwater isoscape for the Baltic region, which covers the major part of the Baltic Artesian Basin (BAB). BAB is an important palaeogroundwater reservoir, but prior to this study, little has been known about the spatial variability of δD and δ18O values in modern precipitation input across the region. To overcome this limitation, we hypothesized that the isotopic composition of shallow groundwater in the BAB could be used as a proxy for the mean weighted annual isotopic composition of local precipitation. However, the results of the study reveal many clear discrepancies between the isotopic composition of precipitation and shallow groundwater in the area. The …
Twenty-three unsolved problems in hydrology (UPH) – a community perspective
This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused on the process-…
Geochemical classification of groundwater using multivariate statistical analysis in Latvia
Multivariate statistical methods – principal component analysis (PCA) and hierarchical cluster analysis (HCA) – are applied to identify geochemically distinct groundwater groups in the territory of Latvia. The main processes observed to be responsible for groundwater chemical composition are carbonate and gypsum dissolution, fresh and saltwater mixing and ion exchange. On the basis of major ion concentrations, eight clusters (C1–C8) are identified. C6 is interpreted as recharge water not in equilibrium with most sediment forming minerals. Water table aquifers affected by diffuse agricultural influences are found in C3. Groundwater in C4 reflects brine or seawater admixture and gypsum dissol…
An insight into water stable isotope signatures in temperate catchment
Abstract Stable isotopes are used to decipher hydrological processes in watershed research. A two-year monthly monitoring of hydrogen and oxygen stable isotope ratios (δ2H and δ18O) in a temperate catchment in Norther Europa, Latvia was undertaken. Isotope ratios in common water types – raised bog, confined groundwater, unconfined groundwater and surface water – were measured. We found characteristic signatures of isotope ratios for each of these four water types. The average isotope ratios of different water types ranged from −80.8 to −68.3‰ for δ2H and −11.46 to −8.76‰ for δ18O, with standard deviations from 18 to 25‰ and 0.10 to 1.59‰, respectively. The isotope ratios of the stream base …
Long-term phenological data set of multi-taxonomic groups, agrarian activities, and abiotic parameters from Latvia, northern Europe
A phenological data set collected by citizen-scientists from 1970 to 2018 in Latvia is presented, comprising almost 47,000 individual observations of eight taxonomical groups, in addition to agrarian activities and abiotic parameters, covering in total 159 different phenological phases. These original data published offline in annual issues of the Nature and History Calendar (in Latvian, Dabas un vēstures kalendārs) have been digitized, harmonized and geo-referenced. Overall, the possible use of such data is extensive, as phenological data are excellent bioindicators for characterising climate change and can be used for the elaboration of adaptation strategies in agriculture, forestry, and …