This thesis describes new inversion-oriented methodological developments and their seismological applications. In the first study presented the dynamic source parameters of some local Icelandic earthquakes are studied by employing a time domain moment tensor inversion method. A windowing method for direct P and S phases was used and the inversion was performed for frequencies lower than the associated corner frequency under the double-couple constraint. The inversion algorithm could determine the dynamic source parameters correctly, even under conditions of poor azimuthal coverage. The second study deals with a new method for calculating the empirical Green's function based on inversion of earthquake radiation patterns. The resulting Green's functions then may contain both body and surface waves. The validity of the method was then confirmed by applying the method to some Icelandic earthquakes. The lithosphere-asthenosphere transition along the TOR array is investigated in the last two studies. Separate and simultaneous teleseismic P and S relative arrival-time residuals were inverted via different methods (a singular value decomposition and a quadratic programming method) to investigate the reliability and the resolution of the model. The data were corrected a priori for the effect of travel-time perturbations due to crustal structure. The results indicate that the transition between thinner lithosphere in Germany to the thicker Baltic Shield in Sweden occurs in two sharp and steep steps. A sharp and steep subcrustal boundary is found below the Tornquist Zone, with a less significant transition below the Elbe Lineament. The lithospheric structure appears to be about 120 km thick under the Tornquist Zone, increasing to more than 200 km beneath the Baltic Shield.

<p>This thesis describes new inversion-oriented methodological developments and their seismological applications. In the first study presented the dynamic source parameters of some local Icelandic earthquakes are studied by employing a time domain moment tensor inversion method. A windowing method for direct P and S phases was used and the inversion was performed for frequencies lower than the associated corner frequency under the double-couple constraint. The inversion algorithm could determine the dynamic source parameters correctly, even under conditions of poor azimuthal coverage. The second study deals with a new method for calculating the empirical Green's function based on inversion of earthquake radiation patterns. The resulting Green's functions then may contain both body and surface waves. The validity of the method was then confirmed by applying the method to some Icelandic earthquakes. The lithosphere-asthenosphere transition along the TOR array is investigated in the last two studies. Separate and simultaneous teleseismic P and S relative arrival-time residuals were inverted via different methods (a singular value decomposition and a quadratic programming method) to investigate the reliability and the resolution of the model. The data were corrected <i>a priori</i> for the effect of travel-time perturbations due to crustal structure. The results indicate that the transition between thinner lithosphere in Germany to the thicker Baltic Shield in Sweden occurs in two sharp and steep steps. A sharp and steep subcrustal boundary is found below the Tornquist Zone, with a less significant transition below the Elbe Lineament. The lithospheric structure appears to be about 120 km thick under the Tornquist Zone, increasing to more than 200 km beneath the Baltic Shield.</p>

<p>In order to improve climate- and weather forecasting models, a better knowledge of the physical processes taking place in the lowest part of the atmosphere over the oceans is essential. In these models it is often assumed that the atmospheric boundary layer over sea behaves in the same way as that over land. But, the results show that the processes over sea are significantly different, which has to be accounted for in the models.</p><p>By using long term measurements it is shown that the surface waves play a very important role for the turbulent structure in the marine atmospheric boundary layer. For example, they give rise to a height structure that can not be found over land. A consequence of this is that measurements from a buoy (at a few meters above the surface) need to be treated different than measurements on a ship (at 10-30 m above the surface).</p><p>The wave influence affects the turbulent kinetic energy budget. Besides the height dependency, the imbalance between local production and local dissipation is a function of stability, wave age and wind speed, and the commonly assumed balance can therefore be questioned. This has direct implications for the so called inertial dissipation method, a method often used to determine turbulent fluxes over sea with the aid of measurements from ships and buoys. A comparison with the more direct eddy-correlation method at 10 m height gives that the inertial dissipation method works best for near neutral conditions and growing sea.</p>

<p>Diagenesis and sequence stratigraphy have been formally treated as two separate disciplines in sedimentary petrology. This thesis demonstrates that synergy between these two subjects can be used to constrain evolution of reservoir quality in sandstones. Such integrated approach is possible because sequence stratigraphy provides useful information on parameters such as pore water chemistry, residence time of sediments under certain geochemistry conditions, and detrital composition, which ultimately control diagenesis of sandstones. </p><p>Evidence from five case studies and from literature, enabled the development of a conceptual model for the spatial and temporal distribution of diagenetic alterations and related evolution of reservoir quality in sandstones deposited in paralic environments. Diagenetic alterations that have been constrained within the context of sequence stratigraphy include: (i) formation of kaolinite and intragranular porosity, and mechanical infiltration of clay minerals in sandstones lying at variable depths below sequence boundaries, (ii) formation of pseudomatrix and cementation by calcite, dolomite, and siderite in lag deposits at parasequence boundaries, (iii) cementation by kaolinite, pyrite, and calcite in sandstones lying in the vicinity of parasequence boundaries with coal deposits, (iv) formation of glaucony in condensed interval at parasequence boundaries, transgressive and maximum flooding surfaces, (v) formation of berthierine in fluvial-dominated deltaic deposits of the highstand systems tract, (vi) cementation by calcite in bioclastic sandstones of the transgressive systems tract, and (vii) formation of kaolinite in fluvial deposits of the lowstand systems tract. The distribution of such alterations put important constrains for the pattern of burial diagenesis (e.g., formation of chlorite, illite, quartz), related evolution of reservoir quality in sandstones, and distribution of baffles and barriers for fluid flow in the context of sequence stratigraphy. </p>

<p>Field studies encounter several complicating factors not studied in the models. Examples are oblique convergence, heterogeneous materials and thermal softening by intruding magmas. Within the deeply eroded Svecokarelian orogeny, studies in eastern Bergslagen indicate strain accommodation of the N-S orogenic shortening by regional E-W folding and shear along the conjugate Singö Shear Zone and Ornö Banded Series. Rising temperature resulted in migmatites affecting the strain accommodation resulting in decoupling and rotation of folds along one of the deformation zones.</p><p>Deformation zones developed in convergent orogens have been studied in both analogue models and in nature. These studies have focused on a number of important factors controlling strain accommodation during orogenesis. The models show that the shape of the leading edge of the indenting continent controls whether the initial suture remains active or if an effective indenter develops, the spacing and number of faults, the width of the orogen and the height of the mountains. All these characteristics depend on the rate and spatial distribution of erosion and sedimentation. Erosion decreases the importance of effective indenters and favors shearing on existing faults leading to steeper, longer lived shears bounding narrow orogens. If sediments load the margin (e.g. foreland), the thrusts propagate further outboard widening the orogen. The strain that is accommodated by compaction and shearing along deep décollement and conjugate imbricate shears is episodic in time. This work links episodes of increased rates of erosion and sedimentation to episodes of high uplift rates, i.e. the development of new imbricate thrusts or pop-up wedges.</p>

In order to improve climate- and weather forecasting models, a better knowledge of the physical processes taking place in the lowest part of the atmosphere over the oceans is essential. In these models it is often assumed that the atmospheric boundary layer over sea behaves in the same way as that over land. But, the results show that the processes over sea are significantly different, which has to be accounted for in the models. By using long term measurements it is shown that the surface waves play a very important role for the turbulent structure in the marine atmospheric boundary layer. For example, they give rise to a height structure that can not be found over land. A consequence of this is that measurements from a buoy (at a few meters above the surface) need to be treated different than measurements on a ship (at 10-30 m above the surface). The wave influence affects the turbulent kinetic energy budget. Besides the height dependency, the imbalance between local production and local dissipation is a function of stability, wave age and wind speed, and the commonly assumed balance can therefore be questioned. This has direct implications for the so called inertial dissipation method, a method often used to determine turbulent fluxes over sea with the aid of measurements from ships and buoys. A comparison with the more direct eddy-correlation method at 10 m height gives that the inertial dissipation method works best for near neutral conditions and growing sea.

Diagenesis and sequence stratigraphy have been formally treated as two separate disciplines in sedimentary petrology. This thesis demonstrates that synergy between these two subjects can be used to constrain evolution of reservoir quality in sandstones. Such integrated approach is possible because sequence stratigraphy provides useful information on parameters such as pore water chemistry, residence time of sediments under certain geochemistry conditions, and detrital composition, which ultimately control diagenesis of sandstones. Evidence from five case studies and from literature, enabled the development of a conceptual model for the spatial and temporal distribution of diagenetic alterations and related evolution of reservoir quality in sandstones deposited in paralic environments. Diagenetic alterations that have been constrained within the context of sequence stratigraphy include: (i) formation of kaolinite and intragranular porosity, and mechanical infiltration of clay minerals in sandstones lying at variable depths below sequence boundaries, (ii) formation of pseudomatrix and cementation by calcite, dolomite, and siderite in lag deposits at parasequence boundaries, (iii) cementation by kaolinite, pyrite, and calcite in sandstones lying in the vicinity of parasequence boundaries with coal deposits, (iv) formation of glaucony in condensed interval at parasequence boundaries, transgressive and maximum flooding surfaces, (v) formation of berthierine in fluvial-dominated deltaic deposits of the highstand systems tract, (vi) cementation by calcite in bioclastic sandstones of the transgressive systems tract, and (vii) formation of kaolinite in fluvial deposits of the lowstand systems tract. The distribution of such alterations put important constrains for the pattern of burial diagenesis (e.g., formation of chlorite, illite, quartz), related evolution of reservoir quality in sandstones, and distribution of baffles and barriers for fluid flow in the context of sequence stratigraphy.

Field studies encounter several complicating factors not studied in the models. Examples are oblique convergence, heterogeneous materials and thermal softening by intruding magmas. Within the deeply eroded Svecokarelian orogeny, studies in eastern Bergslagen indicate strain accommodation of the N-S orogenic shortening by regional E-W folding and shear along the conjugate Singö Shear Zone and Ornö Banded Series. Rising temperature resulted in migmatites affecting the strain accommodation resulting in decoupling and rotation of folds along one of the deformation zones. Deformation zones developed in convergent orogens have been studied in both analogue models and in nature. These studies have focused on a number of important factors controlling strain accommodation during orogenesis. The models show that the shape of the leading edge of the indenting continent controls whether the initial suture remains active or if an effective indenter develops, the spacing and number of faults, the width of the orogen and the height of the mountains. All these characteristics depend on the rate and spatial distribution of erosion and sedimentation. Erosion decreases the importance of effective indenters and favors shearing on existing faults leading to steeper, longer lived shears bounding narrow orogens. If sediments load the margin (e.g. foreland), the thrusts propagate further outboard widening the orogen. The strain that is accommodated by compaction and shearing along deep décollement and conjugate imbricate shears is episodic in time. This work links episodes of increased rates of erosion and sedimentation to episodes of high uplift rates, i.e. the development of new imbricate thrusts or pop-up wedges.

The Forsmark Nuclear Plant is one of the largest in Sweden and produces around one sixth of the total electrical energy in the country. It is situated on the east coast of Sweden in the Uppland region. Nuclear waste has to be properly handled every year and Forsmark is one site proposed for long-term storage of all spent fuel from Swedish nuclear power reactors. This potential high-level repository (a low-level one already exists in the area) will be based on the KBS-3 design process, which consists of 6000 iron-copper capsules where the waste will be stored for 30 years and finally buried 500 m down, isolated from the environment for100.000 years. Before using the disposal site, numerous investigations must be done in the area so the risks are reduced as much as possible. These investigations include drilling of cored boreholes down to 1000 m depth. In this study the KFM01A borehole (figure 1.1) was used with different shot points to analyze possible anisotropy in the subsurface. The anisotropy in rocks can be due to different mechanisms as crystal and mineral grain alignment, crack and pore space alignment and thin layer anisotropy (Rowlands J. et al., 1993). For this purpose a shear wave splitting analysis was done in an attempt to determine both orientation and density of fractures. Shear wave splitting has shown to be a very effective method detecting fractures, providing an unique ability to measure anisotropic seismic attributes that are sensitive to fractures (James E. Gaiser, 2004). This can be useful in many domains as in oil companies to improve reservoir management (James E. Gaiser, 2004) or as an imaging tool in fracture-controlled geothermal reservoirs, to monitor fluid pressure in the cracks and changes in crack density (Tang Chuanhai, 2005). Shear wave splitting studies have also been done in seismology for crustal studies (Rowlands J. et al., 1993). When shear waves enter anisotropic medias they split in two approximately orthogonal components, where the faster and slower components will travel parallel and perpendicular to the fracture planes respectively. The time delay will depend of the amount of anisotropy and the path length. Different methods can be used to evaluate the anisotropy; polarization diagrams (Crampin et al., 1986), linear moveout plots of the horizontal components (Li et al.,1988).The procedure described by Li et al. (1988) are the techniques that are used in the present study. The fractures orientation is also analyzed and compared with the general stress components in the area using well bore information from previous studies, as well as the general tectonic characteristics of the zone.

<p>This study is concerned with speciation and fractionation of the rare earth elements (REE) and calcium (Ca) in aqueous solutions. The aim is to investigate the chemical states and physical sizes in which these elements can be present. The REE (including neodymium) and Ca have contrasting geochemical behavior in aqueous solutions. Ca is a major dissolved element, while the REE are trace components and highly reactive with aquatic particles.</p><p>The major interests of the five papers included in this thesis are the following:</p><p>· Papers I and V deal with the behavior of neodymium (Nd) and its isotopes in the Kalix River and some marine waters.</p><p>· The diffusive gradients in thin-films (DGT) method is developed for measuring Ca and Mg in Paper II.</p><p>· Paper III presents a speciation and fractionation study of Ca in the Kalix and Amazonian rivers.</p><p>· The rare earth elements and their carrier phases are investigated in the Kalix river in Paper IV.</p><p>For most elements a detailed study of speciation and fractionation can not be performed using only one method. This is due to the overall heterogeneity of the material, considering both size and chemical composition, which is present in aquatic solutions. During this project the aquatic geochemistry of the REE and Ca has been studied using mainly three methods; cross-flow filtration (CFF), field-flow fractionation (FFF) and diffusive gradients in thin-films (DGT). Field work has to a large part been conducted in the Kalix River, in northern Sweden, which is one of the last pristine river systems in Europe. Some field work has also been conducted in the Baltic Sea and the Arctic Ocean. Results from Amazonian rivers are also presented.</p><p>These are the main conclusions from this work:</p><p>The DGT technique works equally well for measuring Ca and Mg in natural waters as previously reported for trace metal.</p><p>A significant colloidal phase for Ca could be detected in the Kalix River and in different Amazonian rivers. This was concluded independently using both CFF and FFF.</p><p>Variations in REE signatures in the Kalix River suggests two different pathways for the REE during weathering and release form soil profiles and transport in the river.</p><p>No significant variation in Nd-isotopic composition could be detected in the Kalix River although concentrations varied by a factor of ~10. This suggests that there is one major source for Nd in the river although different pathways for the REE may exist.</p><p>A study of Nd in the Kalix River, the Baltic Sea and the Arctic Ocean showed that the isotopic compositions in the diffusible fractions were similar to water samples. However, the relative amount of diffusible Nd increased with salinity, probably reflecting the lower concentration of colloidal and particulate material in marine waters.</p>