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135 results on '"Satkūnas, Jonas"'

4. The dynamics of Pilkosios Dunes relief during 2010-2022, based on the digital elevation model analysis.

Author

Tijūnaitytė, Gabrielė, Danielius, Simonas, Bevainis, Linas, Satkūnas, Jonas, and Balakauskas, Lauras

Subjects
DIGITAL elevation models, SAND dunes, SHORELINES, LANDFORMS
Abstract

To assess aeolian relief dynamics in Pilkosios Dunes, 6 digital elevation models (DEMs) were prepared from the year 2010, for January, May and October of 2018, for May of 2019, and for November of 2022. These DEMs were then compared with each other to obtain elevation difference rasters through time. The obtained results indicated that elevation changes were directional through time, and their highest intensity coincided with the bare-sand surface class, where active blowout landforms were located. In these locations, the average negative elevation change rate was determined to be approximately 2 cm/year. To analyse the driving forces of these elevation changes, the relationships between a measure of elevation change and the tested factor characteristics were evaluated. The strongest relationship amongst all tested factors was found with the distance to the edge of grassland/bare sand. Locations that were farther away from this edge experienced a four times larger decrease in elevation, compared to areas closer to the edge. The distance to the shoreline, which is related to the absolute altitude, was also an important factor. This relationship can be summarized as follows: the lowest areas, which were further from the lagoon, were inactive; while the highest locations, which were closer to the shoreline, had the highest intensity of elevation change (averaging 0.5-0.7 m for adjacent to the shoreline locations and-1.7 m for locations ~ 300 m away from the shoreline). The slope factor described a trend of how the steepest slopes were decreasing in height by 2 m on average, while gentler slopes were mostly stable. [ABSTRACT FROM AUTHOR]

Published
2023
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5. New 14C data of megafaunal remains from Lithuania - implications for the palaeoenvironmental interpretation of the Middle Weichselian

Author

Satkūnas, Jonas, Girininkas, Algirdas, Rimkus, Tomas, Daugnora, Linas, Grigienė, Alma, Stančikaitė, Miglė, Slah, Gvidas, Skuratovič, Žana, Uogintas, Domas, and Žulkus, Vladas

Subjects
14C, Middle Weichselian, environmental dynamics, Mammuthus primigenius Blumenbach, Lithuania, Rangifer tarandus Linnaeus, 1758
Abstract

Palaeobiological data, supplemented by new 14C dates in conjunction with palaeobotanical and lithological information, have allowed reconstruction of Middle Weichselian (MIS 3) environmental fluctuations in the southern Eastern Baltic region. Palaeoenvironmental reconstructions implying non-glacial conditions during the Middle Weichselian (MIS 3) are supported by the spatial and temporal context of recently discovered remains of Mammuthus primigenius Blumenbach and Rangifer tarandus Linnaeus, 1758. Recording both cold and warm climatic reversals of MIS 3, representatives of the megafauna thrived in an environment characterized by a heterogeneity of vegetation and climate. 14C dating shows that the majority of the megafaunal remains analysed represent the 38-45 cal kyr BP time-interval, which correlates with the Nemunas 2c cold interval (cryomer), and the 31-34 cal kyr BP or Mickunai 3 thermomer. From pollen data, the palaeovegetation pattern varied from tree-less tundra to birch-predominating forest with an admixture of temporal tree species providing additional informa-tion about the diet and habitat preferences of these herbivores in the context of the MIS 3 climatic events.

Published
2023

7. Mercury and methylmercury in Baltic Sea sediments, and Polish and Lithuanian soils

Author

Ignatavičius, Gytautas, Unsal, Murat H., Busher, Peter E., Wołkowicz, Stanisław, Satkūnas, Jonas, and Valskys, Vaidotas

Subjects
mercury, sediment, Baltic Sea, Geology, methylmercury, Lithuania, Poland, soil
Abstract

We review the current environmental pollution by mercury in the soils of Poland and Lithuania and in the sediments of the Baltic Sea. Mercury is documented to have many negative impacts on the environment as a toxic trace element. In many different chemical forms, it is being released into the environment by both geogenic and anthropogenic activities, with most being released from anthropogenic sources. Methylmercury is considered one of the most toxic forms found in the environment. Mercury levels in sediment and various point sources increased after World War II in the Baltic Sea, which was used as a dumpsite. Previous studies show noticeable differences in total mercury in the Baltic Sea. In the Warta and Odra rivers in Poland, mercury levels are also higher than the background value, though recent findings suggest that river sediments are not the main source of mercury to marine sediments. Concentrations in soils in Poland and Lithuania were below the level of limit values (1 and 1.5 mg/ kg−1 respectively), but Upper Silesia showed concentrations (up to 4.01 mg·kg−1) above the limit values. Furthermore, between 1992 and 2006, mercury levels in Wrocław dropped dramatically. The dominant trees in the area can affect mercury accumulation. No data were available for comparison with the soils in Estonia and Latvia.

Published
2022

10. Karst and Ecosystems

Author

Taminskas, Julius, Paskauskas, Ricardas, Zvikas, Audrius, Satkunas, Jonas, Zektser, Igor S., editor, Marker, Brian, editor, Ridgway, John, editor, Rogachevskaya, Liliya, editor, and Vartanyan, Genrikh, editor

Published
2006
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13. Heavy metals in sapropel of lakes in suburban territories of Vilnius (Lithuania): reflections of paleoenvironmental conditions and anthropogenic influence

Author

Ignatavičius, Gytautas, Satkūnas, Jonas, Grigienė, Alma, Nedveckytė, Irena, Rahidul Hassan, Howlader, and Valskys, Vaidotas

Subjects
water pollution, paleoenvironment, environmental impact assessment, sapropel, lakes geochemistry, heavy metals, environmental sustainability, Geology, Geotechnical Engineering and Engineering Geology, Mineralogy, QE351-399.2
Abstract

Geochemical and lithological parameters of sapropel in lakes, combined with pollen data and radiocarbon 14C dating, contain a wide spectrum of environmental information. This includes records of fluctuations of water level and changes of conditions of sedimentation, accumulation of organic matter and chemical elements due to climate change, human impacts and other environmental changes. Rising concentrations of hazardous substances in the natural sediments are likely to be a high risk to the natural environment. At the same time, they can greatly reduce opportunities for environmental engineering of lakes. Four lakes with different trophic states and anthropogenic pressures were chosen for this study in Lithuania. Higher concentrations of elements like Cr, Cu and Zn were not only detected in the top most layers of sapropel but also in deeper layers and are attributed to lithogenic association of trace elements in such deep layers. Concentrations of Pb were detected only in upper layers of sapropel which indicates the impact of anthropogenic activity. The main source of heavy metals was multidimensional anthropogenic pollution leading to a biogenic–anthropogenic association of elements. Sapropel with low concentrations of heavy metals exhibits a different inter-association matrix because most of the elements tend to form lithogenic–clastogenic associations.

Published
2021

31. LIETUVOS GEOLOGIJOS TARNYBOS TAPSMAS IR RAIDA - AR ISTORIJA GALI BŪTI NAUDINGA ATEIČIAI?

Author

Satkūnas, Jonas

Subjects
PROSPECTING, GEOLOGICAL modeling, GEOLOGICAL maps, DRILL core analysis, INTERNATIONAL cooperation, GEOLOGICAL mapping, GEOLOGICAL surveys
Abstract

Lithuanian Geological Survey (LGS) is operating since 1940 as institution with its history, defined role, institutional memory, traditions and stock of geological information (including archives and core storage). History of LGS is discussed by dividing into three periods: 1940-1958, 1958-1991 and since the year 1991. In the period 1941-1991 under the Soviet regime the works of geological exploration (mapping, prospecting and exploration, drilling of boreholes, etc.) were carried out very intensively and resulted in great amount of geological information (reports, maps, collections of cores and samples). Since 1991 LGS is being developed under the model of Geological Surveys of most West European countries. Currently LGS have 3 main tasks: 1) geological research; 2) regulation of the use of underground; 3) state information system. Wide range of opportunities are related with number of new environmental aspects for research, international cooperation projects, etc. LGS is capable for better cooperation with national institutions presenting them value of geological information. Geological mapping must be developed as a way of comprehensive understanding of subsurface. [ABSTRACT FROM AUTHOR]

Published
2021

35. How to demonstrate the role of geology in a modern society: the case of Lithuania, where geology is not visible

Author

Satkūnas, Jonas

Abstract

Lithuania is a comparatively small country (65 000 km2) with prevailing flat, glacial and post glacial relief composed of soft sediments without any rocky formations visible on the surface. There are no underground mines, but rather only pits for sand and gravel and few quarries of dolomite and limestone. Oil is produced from 15 oil fields in the west of the country. All potable water is taken from aquifers, with negligible if any concern. Most people, therefore, know very little about the geology of Lithuania and hardly realize what the Geological Survey is doing. Only in rare cases of hazardous events, like the Kaliningrad earthquake in 2004, or landslides devastating Gediminas Hill in 2016–17, or the largest karst sinkholes, is the name of the Geological Survey visible in the mass media. Nevertheless, the Geological Survey operates with several duties, private sector geological companies are generating business, and geosciences are on the agenda of scientific institutions. The aim of this study is to take a deeper look into the current factors that are determining the role of the Geological Survey of Lithuania at present, and to outline circumstances which could influence the role of the Survey in the future.

Published
2020
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37. Vertical ground movements in the Polish and Lithuanian Baltic coastal area as measured by satellite interferometry

Author

Graniczny, Marek, primary, Čyžienė, Jolanta, additional, van Leijen, Freek, additional, Minkevičius, Vytautas, additional, Mikulėnas, Vidas, additional, Satkūnas, Jonas, additional, Przyłucka, Maria, additional, Kowalski, Zbigniew, additional, Uścinowicz, Szymon, additional, Jegliński, Wojciech, additional, and Hanssen, Ramon, additional

Published
2015
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39. Research of Earth’s crust strains and stresses by geodetic method (Baltic region example)

Author

Zakarevičius, Algimantas, Šliaupa, Saulius, Petroškevičius, Petras, Kazlauskas, Kazys, Ødegård, Rune Strand, Rybokas, Mindaugas, Vekteris, Vladas, Paršeliūnas, Eimuntas Kazimieras, Satkūnas, Jonas, Vilnius Gediminas Technical University, Levinskaitė, Daiva, Zakarevičius, Algimantas, Šliaupa, Saulius, Petroškevičius, Petras, Kazlauskas, Kazys, Ødegård, Rune Strand, Rybokas, Mindaugas, Vekteris, Vladas, Paršeliūnas, Eimuntas Kazimieras, Satkūnas, Jonas, Vilnius Gediminas Technical University, and Levinskaitė, Daiva

Abstract

The aim of the work is to establish values of current Earth‘s crust strains and geodynamic stresses in the Baltic region, analyse their spread. The following tasks need to be solved to achieve research objective: 1) Work up an improved technique for evaluation of current Earth’s crust movement values keeping in mind spheroidal shape of the Earth; 2) Applying developed technique make an evaluation of Earth’s crust movement characteristics; 3) Prepare a method of accuracy appraisal of calculated Earth’s crust strains values; 4) Applying this technique conduct an analysis of accuracy and reliability of current established Earth’s crust strains values; 5) Examine regularities of current Earth’s crust strains and their dispersion characteristics. Introduction grounds the research problem, defines problem topicality, states the research objective and tasks, describes scientific novelty of the research, provides theses hypotheses, presents author's publications and reports at conferences, and describes structure of the thesis. The first section analyses scientific literature of Earth‘s crust movement determination according to repeated geodetic measurement data. Topical research issues and tasks are stated to achieve the research objective. The second section examines current technique of evaluation of Earth‘s crust strains values and stresses based on geodetic measurement data. New method of accuracy appraisal of Earth’s crust strains values is provided. Improved evaluation... [to full text], Disertacijos tikslas – ištirti dabartines Žemės plutos deformacijas ir įtempius Baltijos regione, nustatyti deformacijų rodiklių sklaidos dėsningumus. Darbo tikslui pasiekti reikia spręsti šiuos uždavinius: 1) Parengti patobulintą metodiką dabartinių Žemės plutos judesių rodiklių nustatymui, įvertinant Žemės formos sferoidiškumą; 2) Taikant parengtą metodiką, įvertinti dabartinių Žemės plutos judesių charakteristikas; 3) Parengti apskaičiuotų Žemės plutos deformacijų rodiklių tikslumo įvertinimo metodiką; 4) Taikant parengtą metodiką, atlikti nustatytų dabartinių Žemės plutos deformacijų rodiklių tikslumo bei patikimumo analizę; 5) Ištirti dabartinių Žemės plutos deformacijų dėsningumus ir sklaidos ypatumus. Disertaciją sudaro įvadas, keturi skyriai ir bendrosios išvados. Įvade pagrindžiama tiriamoji problema, apibrėžiamas problemos aktualumas, formuluojamas darbo tikslas bei uždaviniai, aprašomas mokslinis darbo naujumas, pateikiami ginamieji disertacijos teiginiai, pristatomos autoriaus publikacijos ir pranešimai konferencijose, aprašoma disertacijos struktūra. Pirmajame skyriuje nagrinėta mokslinė literatūra Žemės plutos judesių nustatymo pagal kartotinių geodezinių matavimų duomenis klausimais. Suformuluoti probleminiai tyrimų klausimai bei uždaviniai darbo tikslui pasiekti. Antrajame skyriuje išnagrinėta dabartinių Žemės plutos deformacijų rodiklių bei įtempių įvertinimo metodika pagal geodezinių matavimų duomenis. Pateiktas naujas nustatytų Žemės plutos deformacijų... [toliau žr. visą tekstą]

Published
2013

42. Development of the Late Glacial and Holocene forest vegetation in Lithuania, according to LRA (Landscape Reconstruction Algorithm) modelling data

Author

Kabailienė, Meilutė, Mazeika, Jonas, Šinkūnas, Petras, Paršeliūnas, Eimuntas, Kisieliene, Dalia, Baltrūnas, Valentinas, Satkūnas, Jonas, Vaikutienė, Giedrė, Šeirienė, Vaida, Vilnius University, Balakauskas, Lauras, Kabailienė, Meilutė, Mazeika, Jonas, Šinkūnas, Petras, Paršeliūnas, Eimuntas, Kisieliene, Dalia, Baltrūnas, Valentinas, Satkūnas, Jonas, Vaikutienė, Giedrė, Šeirienė, Vaida, Vilnius University, and Balakauskas, Lauras

Abstract

Most widely used applications of quantitative past vegetation reconstruction are based on pollen-vegetation relationship functions. To carry out detail vegetation reconstruction using this method, large amount of geographic data pre-processing is necessary. For this reason, large scale vegetation reconstructions are extremely rare. In this study data processing is carried out using automated GIS tools. Application of GIS enabled precise and detail reconstruction of the Late Glacial and Holocene forest vegetation composition, as well as the development of vegetation in Lithuania. New pollen investigations from cores and outcrops, created Lithuanian pollen database, evaluation of pollen-vegetation relationship functions in the environment of Lithuania and reconstruction of main tree species composition in the Late Glacial and Holocene, according to pollen database and selected pollen-vegetation relationship function are presented in this study. The created palaeovegetation maps enbled considerable detalization of knowledge about past vegetation in Lithuania. Consequently, main vegetation migration and distribution patterns were defined., Plačiausiai naudojami kiekybinio praeities augalijos taksonominės sudėties atkūrimo pagal žiedadukių duomenis metodai remiasi žiedadulkių-augalijos priklausomybės funkcijomis. Norint atlikti detalų augalijos sudėties atkūrimą šiuo metodu, reikalingos itin didelės apimties geografinių duomenų apdorojimo procedūros, todėl stambiu masteliu augalijos sudėtis atkūriama itin retai. Šiame darbe duomenų apdorojimas atliekamas automatizuotomis GIS priemonėmis. GIS panaudojimas leido tiksliai ir detaliai atkurti Lietuvos vėlyvojo ledynmečio ir holoceno miško augalijos taksonominę sudėtį bei augalijos vystymosi raidą. Disertaciniame darbe pristatomi nauji gręžinių ir atodangų nuosėdų žiedadulkių tyrimai, sudaryta Lietuvos žiedadulkių duomenų bazė, atliktas įvairių žiedadulkių-augalijos priklausomybės funkcijų įvertinimas Lietuvos sąlygose, žiedadulkių duomenų bazės pagrindu pagal pasirinktą priklausomybės funkciją atkurta pagrindinių medžių taksonų sudėtis eilei vėlyvojo ledynmečio ir holoceno laikotarpių. Sudarytais praeities augalijos paplitimo žemėlapiais reikšmingai detalizuotos žinios apie praeities augaliją Lietuvoje, nustatyti pagrindiniai augalijos migracijos keliai ir jos paplitimo dėsningumai.

Published
2012

43. Vėlyvojo ledynmečio ir holoceno miškų augalijos raida Lietuvoje LRA (Kraštovaizdžio atkūrimo algoritmo) modeliavimo duomenimis

Author

Kabailienė, Meilutė, Mažeika, Jonas, Šinkūnas, Petras, Paršeliūnas, Eimuntas, Kisielienė, Dalia, Baltrūnas, Valentinas, Šeirienė, Vaida, Satkūnas, Jonas, Vaikutienė, Giedrė, Vilnius University, Balakauskas, Lauras, Kabailienė, Meilutė, Mažeika, Jonas, Šinkūnas, Petras, Paršeliūnas, Eimuntas, Kisielienė, Dalia, Baltrūnas, Valentinas, Šeirienė, Vaida, Satkūnas, Jonas, Vaikutienė, Giedrė, Vilnius University, and Balakauskas, Lauras

Abstract

Plačiausiai naudojami kiekybinio praeities augalijos taksonominės sudėties atkūrimo pagal žiedadukių duomenis metodai remiasi žiedadulkių-augalijos priklausomybės funkcijomis. Norint atlikti detalų augalijos sudėties atkūrimą šiuo metodu, reikalingos itin didelės apimties geografinių duomenų apdorojimo procedūros, todėl stambiu masteliu augalijos sudėtis atkūriama itin retai. Šiame darbe duomenų apdorojimas atliekamas automatizuotomis GIS priemonėmis. GIS panaudojimas leido tiksliai ir detaliai atkurti Lietuvos vėlyvojo ledynmečio ir holoceno miško augalijos taksonominę sudėtį bei augalijos vystymosi raidą. Disertaciniame darbe pristatomi nauji gręžinių ir atodangų nuosėdų žiedadulkių tyrimai, sudaryta Lietuvos žiedadulkių duomenų bazė, atliktas įvairių žiedadulkių-augalijos priklausomybės funkcijų įvertinimas Lietuvos sąlygose, žiedadulkių duomenų bazės pagrindu pagal pasirinktą priklausomybės funkciją atkurta pagrindinių medžių taksonų sudėtis eilei vėlyvojo ledynmečio ir holoceno laikotarpių. Sudarytais praeities augalijos paplitimo žemėlapiais reikšmingai detalizuotos žinios apie praeities augaliją Lietuvoje, nustatyti pagrindiniai augalijos migracijos keliai ir jos paplitimo dėsningumai., Most widely used applications of quantitative past vegetation reconstruction are based on pollen-vegetation relationship functions. To carry out detail vegetation reconstruction using this method, large amount of geographic data pre-processing is necessary. For this reason, large scale vegetation reconstructions are extremely rare. In this study data processing is carried out using automated GIS tools. Application of GIS enabled precise and detail reconstruction of the Late Glacial and Holocene forest vegetation composition, as well as the development of vegetation in Lithuania. New pollen investigations from cores and outcrops, created Lithuanian pollen database, evaluation of pollen-vegetation relationship functions in the environment of Lithuania and reconstruction of main tree species composition in the Late Glacial and Holocene, according to pollen database and selected pollen-vegetation relationship function are presented in this study. The created palaeovegetation maps enbled considerable detalization of knowledge about past vegetation in Lithuania. Consequently, main vegetation migration and distribution patterns were defined.

Published
2012

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