Browsing by department "Geotieteiden ja maantieteen osasto"

Understanding the factors that affect the climate and the resulting chemical and physical processes will help to develop better climate models. This requires long-term measurements of carbon exchange between the earth and the atmosphere, as well as information on the spatial distribution of different bog nutrient classes and their microtopographic forms, in order to better understand the effects of climate change on different temporal and spatial scales. My master's thesis focuses on the separation of hummocks, interfaces and wet surfaces in the Simoskanaapa bog, which belongs to the Ostrobothnia-Kainuu bog zone, by means of remote sensing, image processing and guided classification. The material used was a high-resolution Optical satellite image of WorldView-2 and an altitude model interpolated to a pixel size of 2 meters, created from the laser scanning data of the National Land Survey of Finland. Object-based classification and support vector machines were used in the guided classification. Object-based classification is suitable for data containing noise, such as remote sensing data taken from bogs. The classification was successful in the ombrotrophic raised bog area of the Simoskanaava bog: the classification accuracy of the six microtopographic forms was calculated to be 84.1% (kappa 0.672). At the aapa-mire, the accuracy of the overall classification was slightly lower for the five classes (76.3%, kappa 0.650), due to the mixing of the interface wet surface levels and intermediate-wet surface levels. Object-based classification is well suited for the classification of certain bog microsites. In my study, it was possible to distinguish well the ridges and wet surfaces of the aapa mire, ridges and wet surfaces of the ombrotrophic raised bog area, and the intermediate sphagnum sp. surfaces. Further research can use more accurate laser scanning data as well as high-resolution satellite imagery to classify the bog into bog types for which emission factors are calculated using the bog's carbon balances

The two input rivers of Säkylä’s Lake Pyhäjärvi: Pyhäjoki and Yläneenjoki, were studied with aerial thermal infrared imaging (TIR) analysis and baseflow program, in order to estimate the baseflow in the two rivers. From the helicopter- assisted TIR survey made in July 2011, almost 200 groundwater discharge sites were located in the two studied rivers. The groundwater discharge anomalies were categorized in 5 different classes: 1) spring/springs, 2) cold channel connected to the main channel, 3) diffuse discharge to river, 4) wetland/ wide seepage, 5) unknown anomaly. In addition, a temperature analysis was performed from the studied rivers. In both rivers, pattern of increasing river water temperature from headwaters towards river outlet were discovered with temperature analysis. The baseflow share estimate was made with baseflow filtering program which uses recursive digital filter for signal processing. Mean baseflow share estimation from four years: 2010-2013, were 70 % for River Pyhäjoki and 54 %, for River Yläneenjoki. Larger baseflow portion, lower river water temperature and wide diffuse discharge areas of River Pyhäjoki indicate that Pyhäjoki is more groundwater contributed than River Yläneenjoki. Previous studies made from the Lake Pyhäjärvi catchment have signs of higher groundwater share in River Pyhäjoki catchment, as well. However, TIR and baseflow estimation results of this study have to be dealt with caution. TIR results represent momentary circumstances and GWD locations are interpretations. There are also many factors increasing the uncertainty of the temperature analysis and observations of GWD anomalies. The results of baseflow analysis has to be interpreted carefully too because baseflow filtering is pure signal processing. However, this study shows that River Pyhäjoki and River Yläneenjoki have groundwater contribution. There is a difference in groundwater share in the two studied rivers. In River Pyhäjoki the larger groundwater share (70 %) is related to coarser grained glacial deposits in the river catchment. In TIR results, the influence of headwaters of the River Pyhäjoki, fed by two large springs: Myllylähde and Kankaanranta were emphasized. The two feeding springs are connected to the Säkylä-Virttaankangas esker complex. In River Yläneenjoki catchment, where GW portion was estimated to be smaller (54 %) and GW anomalies where mostly discrete, there are only two little till groundwater areas near the river channel and the catchment is characterized by finer sediments than River Pyhäjoki catchment.

Autonomous Administration of North and East Syria, AANES, was established in 2012. It is de facto independent region and it hopes to operate as a part of unified Syria following principles of democratic confederalism. The aim of this research is to understand and explain AANES using theoretical background of anarchist geography, which is one field of radical political geography. The study navigates the research question of how society could be formed without state and what kind of spatial dimension such kind of post-statist society would have. The key readings on theory are Simon Springer’s (2016) Anachist Roots of Geography – Towards Spatial Emancipation, and Marcelo de Lopez de Souza’s, Richard White’s ja Springer’s (eds.) (2016) Theories of Resistance – Anarchism, Geography and the Spirit of Revolt. The study draws on the data collected outside the research area through interviewing 7 research participants. The data is analyzed using deductive dialogical thematization, by arranging the findings into different themes. The findings offer insight into components of post-statist building of society. The thematic components which were salient in the findings are building new spaces; questioning state; accepting the diversity of the region; undoing hierarchies and using anarchist means. The findings demonstrate that anarchist geography is useful tool to understand and study post-statist formation of society of AANES.

Insecure residential areas have been found to be associated with socio-economic disadvantage and possible regional segregation. In addition, feeling of insecurity reduce quality of life and mental health. Based on many studies, residents experience insecurity more often in suburban areas dominated by apartment buildings. This study examines the relationship between building height and block structure and residents' feeling of insecurity in Finnish suburbs. The relationship between the residential block structure and feeling of insecurity has not been studied before, which is why this research can bring new ideas to the scientific debate. Research data includes survey data collected from 71 Finnish suburbs, contextual register data aggregated from the grid database and basic information from Finnish Population Register. Quantitative statistical methods are used in this study. The block structure is classified utilizing GIS methods. The study takes into account socio-economic factors influencing insecurity by examining the phenomenon also under different socio-economic variables. Based on the results of the study, there is no significant relationship between building height and feeling of insecurity at any case. However, there is a significant connection between the block structure and feeling of insecurity. The results show that residents living in neighbourhood with more closed block structure experience more insecurity. Statistical connection between block structure and feeling of insecurity became stronger when the socio-economic variables were included to the analyzes. The results of this thesis are related to the findings presented in previous studies about the relationship between the physical environment and safety. However, the significance of the results and the understanding of the phenomenon is not unambiguous and requires further investigation.

This thesis examines a conflict situation, which has initiated in consequence of a war of the past. The framework of the study consists of different approaches of both political and functional geography. The research question is how a long conflict situation appears through different geographical scales and how it relates to processes counterproductive to it, like cross border regionalization, globalization and integration projects of states. As a case study I have the territorial dispute in Atacama between three South American states, Bolivia, Chile and Peru, concerning the territorial division resulting from the War of the Pacific (1879-1883). The dispute touches the most Bolivia, who lost all its coastal territory to Chile and thus remained landlocked. Bolivia demands Chile to return to it a sovereign access to the Pacific coast. Chile finds this demand unfounded because the countries made a peace treaty in 1904, that obliged Chile to construct a railway from the coast to Bolivia and guarantee access to its ports. Bolivia argues its demand by claiming that the treaty was dictated by the winning part and that it’s unfavorable to Bolivia. The conflict involves Peru in the case that Chile would intend to cede formerly Peruvian territories to Bolivia. The treaty of Lima in 1929 obliges Chile to consult Peru before ceding any territory. Chile and Bolivia have negotiated several times in order to solve the dispute, but without results. Bolivia took the affair to the International Court of Justice in The Hague in 2013 expecting the court to force Chile to negotiate a sovereign access to the sea for Bolivia. The court ruling in 2018 was favorable to Chile, so there’s no obligation to negotiate. This was a turning point in the history of the conflict situation. The aim of the study is to show the big picture of the conflict situation, to illustrate the political and functional dimensions of the case and to present possible ways to reach a solution. The source material I have used to this paper consist of media content available online, literature written about this case and theory books. My methods have been observations at the area of the study, content analysis of both literature and online sources and discussion. The presented alternatives for solution are based on either cessation of sovereign territory or on integration without sovereignty. As a conclusion it can be noted that nationalistic identity policy and overemphasized significance of legal sovereignty are factors that tend to maintain and reinforce the conflict. Instead globalization, regionalization and integration are such counteracting processes to the conflict that make it less alluring for the parts to continue it.

Northern peatlands form a globally significant carbon reservoir holding almost one third of global terrestrial organic soil carbon. Peatlands are in constant interaction with the atmosphere and their carbon balance can change from a sink to a source. Climate is the one of the most important factors controlling peatland dynamics and subsequently carbon dynamics. As global warming is predicted to have increasingly strong impacts over the high latitudes, also peatlands will be affected. Peatlands are an environment defined by a certain type of vegetation, which can tolerate excess moisture and of often low pH. Peatland vegetation can be divided based on the preferred habitat conditions. Peatland vegetation compositions are not static, but instead everchanging and they react to changes in climate and environment, observed as shifts from vegetation assemblage to another. I studied the climatic response of peatland vegetation compositions in Lakkasuo bog in Southern Finland. High resolution macrofossil approach was carried out to observe peat vegetation changes trough time, in particular I studied responses to known climate phases. To obtain robust chronologies, both 210Pb and 14C dating was applied. Peat bulk density and C/N ratio was also analysed, carbon accumulation rates calculated, and current vegetation and water table depth (WTD) measured in the field. Three peat sections, 50-60cm from the top, were analysed. Dating revealed that the peat sections reached back c. 300 years. Plant data was statistically analysed using Changepoint to make an objective core-to-core comparison of the changes and the timing of vegetation shifts. Because WTD is largely defining the vegetation compositions in bogs, for Lakkasuo sites three bog microforms, i.e. microhabitats, currently representing different WTD levels were chosen for the palaeoecological analyses. Vegetation was inspected in high plant taxonomical level and as larger compositional groups (plant functional types). For changepoint analyses plant taxa were classified as “dry”, “intermediate” and “wet” based on their preferred moisture conditions today. Macrofossil data indicated clear shifts in vegetation composition in Lakkasuo as a response to the Little Ice Age (LIA) cool period and to current warming. LIA was characterised by presence of wet taxa. Current warming, in turn, is visible as an increase in dry taxa. This leads to the conclusion that climate has been the prevalent controlling factor for the bog vegetation during the last c. 300 years. Current development towards dry conditions in Lakkasuo will affect the peatland carbon dynamics. The peatland is projected to experience decrease in effective moisture hindering carbon uptake capability.

Ferromanganese concretions are commonly found in the Gulf of Finland forming in different sizes and shapes. The concretions are formed in various environments, where known factors contributing to their formation are e.g. the redox properties of the local environment, quality of the seabed associated with the concretions and bottom currents. Ferromanganese concretions are formed by natural geochemical processes, catalyzed by micro-organisms, e.g. archaea and bacteria. The materials of this study were based on altogether 200 samples consisting of sample descriptions, underwater photographs and videos from the northern Gulf of Finland provided by GTK. Environmental variables used in this study were water depth, sediments associated with the concretions, seabed structure type, slope, roughness, distance to coast and distance to river, surface wave exposure, bottom wave exposure and bottom current velocity (m/s). The concretions were categorized into different groups, their distribution was illustrated on a map and environmental variables were used to determine which factors contribute to their formation and to elucidate the characteristics of the environments where each concretion type is formed. Discoidal concretions were the most common concretion type in the study area indicating that the environment of the northern Gulf of Finland is most suitable for these concretions. Discoidal concretions were most commonly found on crests which was also the dominant seabed structure type in the study area. The results show that each concretion type is formed in an environment where certain environmental factors are commonly present. Spheroidal concretions (2–7 mm) were practically missing in the study area which is likely linked to the quality of the seabed and availability of Mn. Buckshot concretions were commonly found in the proximity of the coast, in calm, sheltered and heterogenic environments. Discoidal concretions were found to form in high energy and dynamic environments. The occurrence of crust concretions is likely linked to (high) water depth, relatively high bottom currents and clayey sediments. Irregular and spheroidal concretions (20–600 mm) represent most likely transient or irregular forms of spheroidal concretions forming in unstable conditions. The economic interest towards ferromanganese concretions is likely to grow in the future. The high geodiversity of the seabed in the northern Gulf of Finland is possibly linked to the abundance and diversity of ferromanganese concretions however their ecological significance to the ecosystem is not yet fully understood.

The oldest rocks in Finland are the Archaean grey gneisses of eastern and northern Finland. The Archaean of the Karelian craton spans about 1000 Ma of crustal growth and evolution and forms the core of the Fennoscandian shield. The Karelian province is a complex patchwork of different rock types. The individual formations are of small territorial extent in accordance with often postulated small Archaean plates. Overall, the Karelian craton is a granitoid-greenstone terrain with prevailing TTGs and younger granites, which show increasing level of potassium. The craton also includes a distinct sodic variety of granites that combines features of classical Archaean TTGs and late Archaean high-K granites. A minor number of Mg-rich lithologic units, including adakites and sanukitoids, are reported as well. A small number of A-type granites, syenites and S-type granites are widely distributed and of local nature only. Peculiarly, a large number of TTGs is peraluminous. The formation of Karelian craton may be explained by accretion of small plates, perhaps during the late Archaean supercraton event in a process that at least in later stages included active plate marginal processes.

The Central Finland Granitoid Complex (CFGC) is a large (44,000 km2) plutonic core of a Svecofennian (Paleoproterozoic, 1.91–1.82 Ga) arc complex, formed from collisions of several volcanic arcs and their accretion over the Karelian craton. The CFGC consists mostly of granitic to granodioritic rock types. Mafic-ultramafic plutonic rock types are not common, and they consist of mostly small gabbro-diorite intrusions, which may have ultramafic parts. There are two distinct belts around the CFGC, where Ni-Cu potential mafic-ultramafic intrusions are situated – Vammala and Kotalahti. The intrusions within these belts were formed during the height of magmatism within the CFGC (1.89–1.87 Ga). They host Ni-Cu mineralizations, some of which have been economically exploited. The mineralizations are hosted by olivine-rich ultramafic cumulates. The intrusions formed from hydrous tholeiitic basalts (10–12 wt-% MgO) with arc-type trace element chemistry. The difference between Vammala and Kotalahti type intrusions (clinopyroxene and orthopyroxene-dominated, respectively) are attributed to the rock type of the assimilated country rock. In this thesis, three previously unknown or poorly studied mafic-ultramafic intrusions (Matokulma, Palojärvi, and Hongonniittu) within the CFGC are studied in detail. The petrology, similarity to Vammala-Kotalahti type intrusions, parental magma compositions, ore potential, and petrogenesis of the intrusions are described. Rock samples and field observations were gathered during the summer of 2017. Whole-rock geochemistry, mineral geochemistry, isotope geochemistry, and geophysics are used to describe the petrology of the intrusions. Matokulma and Palojärvi intrusions are studied in detail, compared to Hongonniittu intrusion, which was not studied as intricately. The Matokulma intrusion is the least evolved (whole-rock median Mg#=72) of the studied intrusions and consists of tholeiitic melagabbros where clinopyroxene±orthopyroxene and plagioclase are the main cumulus phases within interstitial, magmatic amphibole (magnesiohastingsite to pargasite in composition). Orthopyroxene and plagioclase are intercumulus phases in some samples. There are also mafic dikes that intrude the tonalitic country rock that surrounds the gabbro. The dikes are similar to the gabbros in geochemistry although they are generally more evolved. Trace element geochemistry suggests that the gabbros and dikes are genetically connected, and the dikes possibly represent the residual magmas of the gabbros. The Palojärvi intrusion is noticeably more evolved than the Matokulma intrusion (median Mg#=49), which is apparent in the iron and titanium rich mineral and whole-rock geochemistry. The strongly tholeiitic melagabbros are composed of both orthopyroxene and clinopyroxene as cumulus phases with plagioclase and common Fe-Ti oxide, often within interstitial magmatic amphibole (magnesio-hastingsite to magnesioferri-hornblende in composition). The Fe-Ti oxides are mostly ilmenomagnetite but both magnetite and ilmenite grains are present in same samples. Based on a few mineral analyzes, the ilmenomagnetite contains up to 1.4 wt-% V2O3. U-Pb age determination samples from a leucogabbro dike within the intrusion and granite that crosscuts the intrusion yielded weighted average 206Pb/207Pb ages of 1883.4±4.8 Ma and 1893.8±7.1 Ma, respectively. The age results are in contrast to the intrusive relationship observed in the field. However, considering the margin of error of the results, the granite can be younger than the gabbro, 1887 Ma and 1888 Ma, respectively. The age of ca. 1.89 Ga is at the early stage of the most voluminous mafic-ultramafic magmatism in the Svecofennian terrane. The parental magmas of the Matokulma and Palojärvi intrusions were evolved and contained approximately 5 wt-% and 2 wt-% MgO, respectively. The presence of magmatic amphiboles in most samples indicate that the parental magmas were hydrous. Samples from all intrusions plot similarly in primitive mantle normalized Rare Earth Element (REE) and Normal-Mid-Ocean Ridge Basalt (NMORB) normalized spider diagrams. Similar patterns indicate a similar source for the parental magmas. The trace element geochemistry has signatures of subduction related fluid metasomatism. The rocks are enriched in large ion lithophile elements (LILE) and depleted in High Field Strength Elements (HFSE). These geochemical characteristics indicate that the studied intrusions crystallized from a hydrous, NMORB-like evolved basaltic magma, which has experienced fluid metasomatism. The studied intrusions differ from olivine-rich ultramafic cumulates of Vammala and Kotalahti type intrusions based on their more evolved, gabbroic composition and because of this, they are not Ni-Cu ore potential. Palojärvi may host a Fe-Ti-V mineralization, if there are magnetite rich layers within the intrusion.

Geochemical ore exploration with geogases is based, like the MMI method, on the movement of mobile metal ions. The assumption is that the buried mineralization is possible to locate using the samples collected from the surface sediment. In this study, the detection of gold-copper anomalies by geogases was tested in three different regions of the West Lapland ice divide zone. Geogas samples were collected using an active gas collector at 25 cm below the lowest visible soil horizon. The samples were bubbled into nitric acid and analysed with ICP-MS. The elements studied were As, Co, Cr, Cu, Fe, Hg, Ni, Pb, U and Zn. Only few elevated levels of arsenic, cobalt, mercury and nickel were found in the gas samples In the Hannukainen mining area, geogases were collected at known ore settlement, in which gas concentrations showed a clear anomaly in soil directly above the outcropping ore. At Kelontekemä, the concentrations of geogases were compared with MMI results from soil samples collected nearby. There appears to be a connection between concentrations of gases and soil samples, but the concentrations of soil samples are often a thousandfold higher. In this study, the Jolhikko region served as a background area, which allowed to conduct a comparison between the area containing mineralization and the background area of precious metals. In light of this research, geogases are a working tool for geochemical ore exploration. However, and in order to understand the complexity of this phenomenon, it is necessary to conduct further studies. The use of geogases also requires special care from samplers to minimize contamination risks.