Located in the far western equatorial Pacific, the Western Pacific Warm Pool (WPWP) is a greater than 10 million km² area of the warmest water on the planet. The WPWP therefore facilitates intense atmospheric convection and participates in coupled ocean-atmosphere climate phenomena such as El Niño Southern Oscillation, regional monsoons, and the shifting Intertropical Convergence Zone. The WPWP is also a water mass crossroads where thermocline-depth western boundary currents (WBCs) such as the New Guinea Coastal Undercurrent (NGCUC) facilitate the transfer of mass, heat, and nutrients vertically, zonally, and meridionally in the ocean. In this dissertation I focus mostly on reconstructing WPWP upper ocean temperature, salinity, nutrient, and productivity dynamics via a suite of physical and geochemical paleoclimate proxies. I apply these proxies in bulk sediments and planktic foraminifera from International Ocean Discovery Program (IODP) Site U1486 over the Pleistocene (2580 ka to 11.7 ka) and Holocene (11.7 ka to present). Site U1486 is located at 2°22’S, 144°36’E in the Bismarck Sea north of New Guinea in the southern WPWP, and is ideally situated to track changes to the WPWP upper water column forced by the South Pacific. The presence of glacial-interglacial (G-IG) variability within WPWP records is particularly important for determining local versus high-latitude climatic influences on the WPWP – with climate shifts such as the mid-Pleistocene Transition (MPT; ~1250 – 700 ka) and mid-Brunhes Event (MBE; ~430 ka) of particular interest in the long-term records I present. In chapter 1, I explore the paleoceanography of the low-latitude Pacific via upper ocean nitrate dynamics. I present a new bulk sediment ẟ¹⁵N record from Site U1486 that spans from 1420 to 0.67 ka – over a million years longer than any nearby records. Via analysis of orbital variability and secular trends at Site U1486 and in records directly along the equator in the Pacific, I find that nitrate dynamics were largely unrelated in the two regions in the Middle and Late Pleistocene. Whereas ẟ¹⁵N at Site U1486 is in line with patterns of eastern Pacific denitrification, increasing ẟ¹⁵N after the MPT at sites located directly along the equator appears linked to increasing Southern Ocean nitrate utilization. Enhanced nitrate utilization is an indicator of a strengthened biological pump – a major contributor to the reduction of atmospheric 𝑝CO₂ during the last glacial. A post-MPT increase in nitrate utilization may therefore point to the Southern Ocean biological pump as a driver for the deeper and longer glacial periods of the 100-kyr world after the MPT. In Chapter 2, I investigate changes in the vertical temperature and salinity structure of the southern sector of the WPWP in relation to the upper ocean’s response to climate change. When combined with Mg/Ca paleotemperatures and δ¹⁸O_sw, my 670-kyr record of Δẟ¹⁸O between the surface-dwelling foraminifera Globigerinoides ruber (sensu stricto) and the thermocline-dwelling foraminifera Pulleniatina obliquiloculata and Globorotalia tumida suggests enhanced thermocline shoaling and a progressively increasing vertical salinity gradient commencing near 240 ka. This secular change in upper water column dynamics does not appear to be associated with previously documented changes in G-IG variability such as the MPT or MBE. Via comparison to other records, I identify widespread cooling of the thermocline in the equatorial Pacific after ~240 ka. After combining these reconstructions with ²³⁰Th-derived focusing factors I validate previous model results indicating obliquity-driven strengthening of low-latitude ocean currents and extend this to imply the periodic increased transport of high-salinity thermocline water masses. These results strengthen previous evidence that the structure of the WPWP thermocline is relatively independent from the drivers of climate at the surface and support that variability in WPWP thermocline circulation is substantially influenced by obliquity. Because of the nitrate dynamics in the Bismarck Sea, bulk sediment ẟ¹⁵N cannot be used to reconstruct productivity. However, chapter 3 constrains variability in productivity via the analysis of new ²³⁰Th-normalized records of preserved biogenic flux and its components at Site U1486 over the last 138 kyr. Here, I assess the drivers of variability in paleo-productivity by reconstructing paleo-stratification, as in the modern Bismarck Sea productivity is stimulated by the delivery of nutrients to the surface during increased upwelling (reduced stratification). Paleo-stratification is approximated by calculating upper ocean density gradients between the calcification depths of G. ruber, P. obliquiloculata, and G. tumida using Mg/Ca temperatures and δ¹⁸O_sw-estimated salinity. Decreased paleo-stratification (a reduced vertical density gradient) was associated with increased productivity and is generally in phase with maximum orbital precession. Paleo-productivity therefore appears to respond to monsoonal increases in coastal upwelling when the Intertropical Convergence Zone (ITCZ) was at its southernmost extent. This illustrates that the unique and more direct method of constraining stratification presented here, which is subject to greater uncertainty, yields results consistent with our current understanding of upper ocean dynamics. I also identify a period between 100 and 60 ka during a potential reorganization of the upper water column in which variability in productivity occurs at a higher frequency than that of precession. Finally, while also related to ITCZ shifts, a nearby record closer to the equator is phase-lagged from Site U1486 – emphasizing the fine-scale regional differences in the drivers of primary productivity in the WPWP.

Seafloor sedimentary depositional and erosional processes create a record of near and far-field climatic and tectonic signals adjacent to continental margins and within oceanic basins worldwide. In this dissertation I study both modern and paleo-seafloor surface processes at three separate and distinct study sites; Cascadia offshore Oregon, U.S.A., the Eastern North American Margin from south Georgia in the south to Massachusetts in the north, and the Deep Galicia Margin offshore Spain. I have the advantage of using modern geophysical methods and high power computing resources, however the study of seafloor processes at Columbia University's Lamont-Doherty Earth Observatory (LDEO) stretches back over ~80 yrs. Specifically I use data collected during a variety of geophysical research cruises spanning the past ~50 yrs.-the majority of which can be directly attributed to seagoing programs managed by LDEO. The modern seafloor is the integrated result of all previous near and far field processes. As such, I look below the seafloor using multi-channel seismic reflection data, which is the result of innumerable soundings stacked together to create an image of the sub-seafloor (paleo) horizons. I map, analyze and interpret the sub-seafloor sedimentary horizons using a variety of both novel and established methods. In turn, I use multi-beam sonar data, which is also the result of innumerable soundings to map, analyze, and interpret the modern seafloor topography (bathymetry). Additionally, I look to the results from academic ocean drilling programs, which can provide information on both the composition and physical properties of sediments. The sediment composition alone can provide important information about both near and far-field processes, however when supplemented with physical properties (e.g., density/porosity) the results become invaluable. In my second chapter, I use a compilation of multi-beam sonar bathymetry data to identify and evaluate 86 seafloor morphological features interpreted to represent large-scale erosional scours not previously recognized on the Astoria Fan offshore Oregon, U.S.A. The Astoria Fan is primarily composed of sediments transported from the margin to the deep ocean during Late Pleistocene interglacial periods. A significant portion of the sediments have been found to be associated with Late Pleistocene outburst flood events attributed to glacial lakes Bonneville and Missoula. The erosional scours provide a record of the flow path of the scouring event(s), which if well understood can provide important information for the study of past earthquakes as the sedimentary record remains intact outside of the erosional force created by the massive flood events. I design and implement a Monte Carlo inversion to calculate the event(s) flow path at each individual scour location, which results in a comprehensive map of Late Pleistocene erosion on the Astoria Fan. The results indicate that at least 4 outburst flood events are recorded by the scour marks. In my third chapter, I build a stratigraphic framework of the Eastern North American margin using a compilation of multi-channel seismic data. Horizon Au is a primary horizon within the stratigraphic framework and is thought to represent a significant margin wide bottom-water erosional event associated with subsidence of the Greenland-Scotland Ridge and opening of Fram Strait in the late Eocene/early Oligocene. A recent study found that the bottom-water was enriched in fossil carbon, leading us to hypothesize that the bottom-water erosion recorded by horizon Au may have been facilitated by chemical weathering of the carbonate sediments. I use sediment isopach(s) to build a margin-wide model of the late Eocene/early Oligocene continental margin in order to estimate the volume of sediments eroded/dissolved during the event marked by horizon Au. The results indicate that ~170,000 km3 of sediments were removed with a carbonate fraction of 42,500 km³, resulting in 1.15e18 mol CaCO₃ going into solution. An influx of this magnitude likely played a role in significant climatic changes identified at the Eocene-Oligocene transition (EOT). In my fourth chapter, I use a combination of 3D multi-channel seismic and multi-beam sonar bathymetry data collected during the Galicia 3D Seismic Experiment in 2013. The Galicia Bank is the largest of many crustal blocks and is located 120 km west of the coast on the Iberian Margin. The crustal blocks have been attributed to the opening of the North Atlantic Ocean in the Late Triassic/Middle Jurassic. The Galicia Bank is the source for the majority of sediments delivered to the Deep Galicia Margin, the focus of this study. I map the seafloor and 5 paleo-seafloor surfaces in order to study controls on sediment delivery provided by the crustal blocks. The results show that the crustal blocks begin as a barrier to and remain a primary control on sediment delivery pathways to the Deep Galicia basin. Additionally, the paleo-seafloor surfaces record morphological structures that can inform us on both near and far field past climatic and tectonic events e.g., the Alpine Orogeny and Pleistocene inter-glacial periods.

The presented study finds its relevance in the issue that history teachers face countless choices when planning their teaching about the European periodization. The study aimed to investigate what teachers choose to teach about in the European periodization, what processes of change and elaboration teachers choose to teach about, how the choices teachers make differ in the history courses 1a1 and 1b, and how teachers’ reason about and motivate the choices they make. This was examined through qualitative interviews with four history teachers who teach/taught in the history courses 1a1 and 1b at the upper secondary school. The analysis was based on these three functions of education: socialisation, subjectification, and qualification. Furthermore, the study aimed to analyze how the functions correlated with the teachers' reasoning about what they choose to teach regarding the European periodization to demonstrate what function the teachers' reasoning had for the students. One overarching conclusion drawn from the study is that when teaching about the European periodization, teachers choose to teach about processes of change and elaboration that clarifies to students why the world function as it does today. Teachers choose to teach about processes of change and elaboration that they believe are interesting for the students and not things they themselves are interested in. The choices teachers make in history 1a1 and history 1b differ in that there are fewer elaboration aspects and more overview in history 1a1 than in history 1b, which may result in the history teaching in history 1a1 being somewhat deficient.

This dissertation examines the longitudinal influences of parental relationships – romantic, co-parenting, and parent-child – on positive adolescent functioning. Utilizing data from the Future of Families and Child Wellbeing Study, this study investigates how various dimensions of parental relationships impact adolescent well-being at age 15, as measured by the EPOCH scale. Grounded in Attachment Theory and the Life Course Perspective, this research highlights the interconnectedness of early parental interactions and their long-term effects on adolescents’ emotional and social development. Key findings indicate that supportive and stable parental relationships significantly enhance adolescents’ engagement, perseverance, optimism, connectedness, and happiness. The study emphasizes the critical role of early family dynamics in shaping positive developmental trajectories and offers insights for interventions aimed at fostering resilient and well-adjusted adolescents. These findings underscore the importance of promoting healthy parental relationships to support adolescents’ overall well-being and successful transition into adulthood.

La successió cuisiana i luteciana de la Conca Sud-pirinenca Oriental (CSO), situada al NE d’Ibèria, mostra un conjunt de sediments carbonatats, evaporítics i detrítics, els quals van ser dipositats en un context compressiu en una conca d’avantpaís. Aquesta compressió es va generar per col•lisió continental de la placa d’Ibèria i l’Europea entre el Cretaci superior i el Miocè inferior. Com a conseqüència de l’escurçament, els sediments es troben distribuïts en tres unitats estructurals: la unitat autòctona de la conca de l’Ebre, localitzada al sud, i les unitats al•lòctones del Serrat i del mantell del Cadí, ubicades al nord, situada la primera per sota de la segona. Encara que molts treballs s’han centrat en l’estudi de l’estratigrafia i l’estructura de la CSO, l’arquitectura estratigràfica i els ambients deposicionals de les evaporites no s’han acabat de resoldre. Les roques evaporítiques dipositades en conques d’avantpaís actuen, en molts casos, com a nivells de desenganxament i, per tant, aquestes roques estan deformades o simplement no afloren. Com a conseqüència, el coneixement d’aquests dipòsits no és molt ampli, i l’estudi d’afloraments i litofàcies resulta un repte. L’objectiu general d’aquesta tesi és millorar aquest coneixement. En aquesta tesi, a partir de la realització de mapes i talls geològics detallats, i de la correlació de columnes i logs de pous, s’ha establert l’arquitectura estratigràfica de la CSO per als períodes Cuisià superior i Lutecià. Aquesta arquitectura presenta sis seqüències deposicionals, tres de les quals de nova proposta en el present treball. Aquestes tres seqüències corresponen a la seqüència Serrat, formada per les Evaporites del Serrat, i a les seqüències Bellmunt inferior i superior, constituïdes per sediments detrítics. Les Evaporites del Serrat, dipositades per sobre d’una primera seqüència carbonatada (formacions Penya i Armàncies), es caracteritzen per tenir capes de sals i lutites en un depocentre situat actualment en el mantell del Cadí. Aquestes sals estan envoltades per un cinturó marginal anhidrític, localitzat en la conca de l’Ebre. En el centre de la conca, aquestes evaporites estan cobertes per una successió turbidítica atribuïda a la Formació Vallfogona (seqüència Campdevànol) en diferents depocentres. Cap als marges de la conca, aquesta formació canvia lateralment a unitats carbonatades (Calcàries de la Pedra i Calcisiltites). La Formació Guixos de Beuda es troba per sobre de la seqüència Campdevànol, i representa la segona seqüència evaporítica. Les seqüències Bellmunt inferior i superior, caracteritzades per dipòsits d’origen fluviodeltaic (formacions Banyoles, Coubet i Bellmunt), representen les seqüències més modernes d’aquesta arquitectura. Aquestes dues seqüències estan separades per una altra unitat evaporítica, anomenada en el present treball Guixos de Besalú. S’ha reconegut que la potència de les capes d’anhidrites atribuïdes a les Evaporites del Serrat és major en la conca de l’Ebre que en el mantell del Cadí. Per tant, s’ha considerat que aquesta unitat es configura, de la conca de l’Ebre fins al mantell del Cadí, com a un tascó anhidrític que passa a una cubeta salina en el centre de la conca. Per contra, també s’ha reconegut que la potència de la Formació Beuda és menor a la conca de l’Ebre que en el mantell del Cadí. L’anàlisi de mostres d’afloraments i de testimonis de pous ha permès interpretar els models sedimentaris de les unitats evaporítiques més representatives. En les Evaporites del Serrat, s’han distingit tres paleoambients, de marge a centre de conca: plataforma sulfatada, constituïda per anhidrita nodular i pseudomòrfica (de selenites); talús, format per guix secundari (anhidrita en profunditat) amb litofàcies laminada, de caràcter detrític; i conca profunda, constituïda per capes de sal i lutites reconegudes només en el subsòl. En canvi, en la Formació Beuda només s’ha reconegut un únic paleoambient, corresponent a un sistema de conca sulfatada situat en el mantell del Cadí. Aquest paleoambient està representat per cicles de guix secundari (anhidrita en profunditat) amb litofàcies massives i nivells pseudomòrfics (de selenites). De tota manera, l’existència d’àrees amb litofàcies bandades i laminades, atribuïdes a ambients més profunds, indiquen l’existència de petites zones més deprimides en la conca. La composició isotòpica (delta-34S, delta-18O; 87Sr/86Sr) de mostres de guix i anhidrita indiquen un origen marí per aquestes unitats i, a més, processos de dissolució/reprecipitació dels sulfats. A partir de l’anàlisi estructural de les correlacions estratigràfiques, dels mapes i talls geològics, de la interpretació de perfils sísmics reprocessats i de noves dades gravimètriques s’ha deduït que la sedimentació durant el Cuisià superior i Lutecià va tenir dues etapes tectòniques: una primera etapa extensiva, coetània amb la sedimentació de les Evaporites del Serrat i la Formació Vallfogona, i caracteritzada per falles normals produïdes per flexió extensional; i una segona etapa compressiva, sincrònica a la sedimentació fluviodeltaica, i caracteritzada per encavalcaments i plecs, i falles transversals de tipus strike-slip. Durant la primera etapa, les falles normals van tenir direccions obliqües i perpendiculars respecte l’escurçament pirinenc (N-S). Durant la segona etapa, les falles de strike-slip van estar generades per la reactivació de falles normals preexistents. A més, les Evaporites del Serrat van actuar com a nivell de desenganxament del mantell del Cadí i de la Unitat Serrat. Finalment, en aquesta tesi, s’han realitzat models sandbox per tal de millorar el coneixement del paper de l’arquitectura estratigràfica d’una successió dúctil (en aquest cas, evaporites) sobre l’evolució estructural. A partir d’una sèrie d’experiments, s’ha observat que l’existència de discontinuïtats geomètriques en els materials anàlegs a les litologies evaporítiques generen zones de deformació preferencial. Comparant els resultats d’aquests experiments amb els trets estructurals de la CSO, s’ha interpretat que l’evolució i estil estructural d’aquesta conca va estar controlada per l’existència de discontinuïtats litològiques –com el canvi de gruix de les anhidrites entre la plataforma evaporítica i la conca profunda– en les Evaporites del Serrat. L’existència d’aquestes discontinuïtats litològiques va generar encavalcaments fora de seqüència, contribuint a la generació d’una conca de piggyback. / The Cuisian and Lutetian succession of the Southeastern Pyrenean Basin (SePB), NE of Iberia, shows an assemblage of carbonate, evaporite and detrital sediments, deposited under a compressional context in a foreland basin. The compression was generated by continental collision of the Iberian and the European plates during the time span comprised between the Upper Cretaceous and the Lower Miocene. As a consequence of the shortening, these deposits were distributed in three structural units: the autochthonous unit of the Ebro Basin, located to the south; and the allochthonous units of the Serrat Unit (below) and the Cadí thrust sheet (above), placed to the north. Despite many studies have been focused on the stratigraphy and the structure of the SePB, the stratigraphic framework and the depositional environments of the evaporites remain poorly understood. In foreland basins, the evaporite rocks usually act as décollement levels, so they are deformed or simply are not outcropping. As a consequence, the knowledge of these deposits is limited, and the study of outcrops and lithofacies is a challenge. The general aim of the present Ph.D. Thesis is to improve this knowledge. In this Ph.D. Thesis, on the basis of geological maps, cross-sections, and sections and welllogs correlations, a stratigraphic framework of the SePB was established for the Late Cuisian and Lutetian times. This framework considers six depositional sequences, and three of them are newly proposed. These three sequences correspond to the Serrat sequence, formed by the Serrat Evaporites, and the Lower and Upper Bellmunt sequences, constituted by detrital sediments. The Serrat Evaporites, deposited on a previous carbonate sequence (Penya and Armàncies formations), are characterized by salt – shale layers in a depocenter located basinward (nowadays in the Cadí thrust sheet). These salt layers are surrounded by an anhydrite marginal belt, placed in the Ebro Basin. In the basin center, these evaporites are covered by turbidite successions attributed to the Vallfogona Formation (Campdevànol sequence) in different depocenters. To the margins, this formation changes laterally to carbonate deposits (Pedra Limestones and Calcisiltites). The Beuda Gypsum Formation is overlying the Campdevànol sequence, and represents the second evaporite sequence. The Lower and Upper Bellmunt sequences, characterized by fluvio-deltaic deposits (Banyoles, Coubet and Bellmunt formations), are the youngest sequences of this succession. These two sequences are divided by another evaporite unit, called Besalú Gypsum in the present work. The anhydrite layers attributed to the Serrat Evaporites were recognized to be thicker in the Ebro Basin than in the Cadí thrust sheet. Thus, the stratigraphic framework of this unit is characterized, from the Ebro Basin to the Cadí thrust sheet, by an anhydrite wedge which changes to a salt deposit in the basin center. By contrast, the Beuda Formation was recognized to be thinner in the Ebro Basin than in the Cadí thrust sheet. The analysis of samples and well-cores allowed to interpret the sedimentary models of the most representative evaporite units. Three paleoenvironments were distinguished in the Serrat Evaporites, from the margin to the basin center: sulphate platform, constituted by anhydrite nodules and pseudomorphs (after selenite gypsum); slope, formed by secondary gypsum (anhydrite in the subsurface) with laminated, detrital lithofacies; and deep basin, constituted by salt and shale layers, only recognized in the subsurface. On the other hand, in the Beuda Formation, only one paleoenvironment, characterized by a sulphate basin, was recognized in the Cadí thrust sheet. This paleoenvironment is represented by cycles of secondary gypsum (anhydrite in the subsurface) with massive and pseudomorphic (after selenite gypsum) lithofacies. However, the existence of areas with banded and laminated lithofacies, attributed to deeper environments, indicates the occurence of small troughs in the basin. The isotopic composition (delta-34S, delta-18O; 87Sr/86Sr) of gypsum and anhydrite samples indicates a marine origin of these units and, also, dissolution/re-precipitation processes of the sulphates. On the basis of the structural analysis of the stratigraphic correlations, the geological maps, the cross-sections, the interpretation of reprocessed seismic profiles and new gravity data, it was deduced that the sedimentation during the Late Cuisian and Lutetian had two tectonic stages: a first extensive stage, coeval to the sedimentation of the Serrat Evaporites and the Vallfogona Formation, and characterized by normal faults generated by flexural extension; and a second compressional stage, coeval to the fluvio-deltaic sedimentation, and characterized by fold-and-thrust and transverse strike-slip faults. During the first stage, the normal faults had oblique and perpendicular directions with respect to the Pyrenean shortening (N-S). During the second stage, the strike-slip faults were generated by reactivation of pre-existing normal faults. Also, the Serrat Evaporites acted as the décollement level of both the Cadí thrust sheet and the Serrat Unit. Finally, in this Ph.D. Thesis, in order to improve the knowledge about the role of the stratigraphic framework of a ductile succession (evaporites, in this case) on the structural evolution, sandbox models were developed. On the basis of a series of experiments, it was observed that the existence of geometrical discontinuities, located in materials analogue of the evaporites, generates zones of preferential deformation. Comparing the results of these experiments with the structural features of the SePB, it was interpreted that the evolution and the structural style of this basin was controlled by the existence of lithological discontinuities –as the case of the thickness change of the anhydrites between the evaporite platform and the deep basin– in the Serrat Evaporites. The existence of these lithological discontinuities generated out of sequence thrusts, contributing to the development of a piggyback basin.

The peninsule of Labrador-Ungava* (Map 1) is a population desert, having harsh, cold winters and brief, warrn, fly-cursed summers, but offering the glacial geomorphologist ample scope for working on virgin territory, with abundant landforrns often of textbook simplicity. However, it is only in recent years thot extensive aerial photography has been undertaken, and this, together wlth certain military and economie developments within the peninsule, has led to an increasing awareness of the significance of the glacial history of the a rea. These developments led ultimately to the establishment in 1954, of the McGi Il Sub-Arctic Research La bora tory, through which it was proposed to develop a scientific research programme related to this little known a rea. With the establishment of the Laboratory, a Field Director was appointed by McGill University to supervise the studies of the younger workers on the staff. A natural outcome of the system was for an emphasis to develop along the lin es of the research interests of the senior man. Under the direction of Dr. J. D. Ives the system developed into what Matthew (196la) has termed the 1 McGill Programme in relation to the deglaciation of the peninsula. [...]

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Funerary Contexts at the Ancón Necropolis from Final Middle Horizon. Analytical Perspectives and InvestigationThis note deals with the potential analytical strength of a series of funerary contexts from Ancón, attributed to Middle Horizon 4 and excavated during 1946 and 1949 by different teams of Peruvian archaeologists. This suggested analysis is based on an appropiate methodology of the reconstruction of contexts parting from extant documentation and associated objects. / En el presente trabajo se expone brevemente las potencialidades de análisis de una muestra de contextos funerarios provenientes del sitio de Ancón, asignados a la Época 4 del Horizonte Medio y excavados entre 1946 y 1949 por diversos equipos de arqueólogos peruanos. Dicho análisis supone el empleo de una metodología apropiada de reconstrucción de los contextos mismos, a partir de los registros (gráficos y escritos) y de los materiales arqueológicos que hasta hoy se han preservado.

Diploma thesis is focused on deformation meassurement of wooden roof structure of Brno Aquapark. Introductory part of the thesis is devoted to explanation of basic terms of civil constructions deformation meassurement and describes methods which are used in this field nowadays. Main part of this thesis deals with testing of meassuring equipment, describes meassured construction, meassuring method and data processing. Horizontal and vertical shifts of the roof structure are evaluated and graphically interpreted in comparison with the previous and fundamental epoch.

Masters of Science / Upcoming and ongoing 21cm surveys, such as the Square Kilometre Array (SKA), Hydrogen Epoch of Reionization Array (HERA) and Low Frequency Array (LOFAR), will enable imaging of the neutral hydrogen distribution on cosmological scales in the early Universe. These experiments are expected to generate huge imaging datasets that will encode more information than the power spectrum. This provides an alternative unique way to constrain the astrophysical and cosmological parameters, which might break the degeneracies in the power spectral analysis. The global history of reionization remains fairly unconstrained. In this thesis, we explore the viability of directly using the 21cm images to reconstruct and constrain the reionization history. Using Convolutional Neural Networks (CNN), we create a fast estimator of the global ionization fraction from the 21cm images as produced by our Large Semi-numerical Simulation (SimFast21). Our estimator is able to efficiently recover the ionization fraction (xHII) at several redshifts, z = 7; 8; 9; 10 with an accuracy of 99% as quantified by the coefficient of determination R2 without being given any additional information about the 21cm maps. This approach, contrary to estimations based on the power spectrum, is model independent. When adding the thermal noise and instrumental effects from these 21cm arrays, the results are sensitive to the foreground removal level, affecting the recovery of high neutral fractions. We also observe similar trend when combining all redshifts but with an improved accuracy. Our analysis can be easily extended to place additional constraints on other astrophysical parameters such as the photon escape fraction. This work represents a step forward to extract the astrophysical and cosmological information from upcoming 21cm surveys.