Fakultät für Geowissenschaften - Digitale Hochschulschriften der LMU

The Earth mantle convects on a global scale, coupling the stress field at every point to every other location at an instant. This way, any change in the buoyancy field has an immediate impact on the convection patterns worldwide. At the same time, mantle convection couples to processes at scales of a few kilometers or even a few hundred meters. Dynamic topography and the geoid are examples of such small-scale expressions of mantle convection. Also, the depth of phase transitions varies locally, with strong influences on the buoyancy, and thus the global stress field. In order to understand these processes dynamically it is essential to resolve the whole mantle at very high numerical resolutions. At the same time, geodynamicists are trying to answer new questions with their models, for example about the rheology of the mantle, which is most likely highly nonlinear. Also, due to the extremely long timescales we cannot observe past mantle states, which calls for simulations backwards in time. All these issues lead to an extreme demand in computing power. To cater to those needs, the physical models of the mantle have to be matched with efficient solvers and fast algorithms, such that we can efficiently exploit the enormous computing power of current and future high performance systems. Here, we first give an extensive overview over the physical models and introduce some numerical concepts to solve the equations. We present a new two-dimensional software as a testbed and elaborate on the implications of realistic mineralogic models for efficient mantle convection simulations. We find that phase transitions present a major challenge and suggest some procedures to incorporate them into mantle convection modeling. Then we give an introduction to the high-performance mantle convection prototype HHG, a multigrid-based software framework that scales to some of the fastest computers currently available. We adapt this framework to a spherical geometry and present first application examples to answer geodynamic questions. In particular, we show that a very thin and very weak asthenosphere is dynamically plausible and consistent with direct and indirect geological observations.

The mitochondria of non-bilaterian metazoans display a staggering diversity of genome organizations and also a slow rate of mtDNA evolution, unlike bilaterians, which may hold a key to understand the early evolution of the animal mitochondrion. Octocorals are unique members of Phylum Cnidaria, harboring several atypical mitochondrial genomic features, including a paucity of tRNA genes, various genome arrangements and the presence of novel putative mismatch repair gene (mtMutS) with various potential biological roles. Thus octocorals represents an interesting model for the study of mitochondrial biology and evolution. However, besides its utility in molecular phylogenetics, the mtDNA of octocorals is not studied from the perspective of DNA repair, oxidative stress response or gene expression; and there is a general lack of knowledge on the DNA repair capabilities and role of the mtMutS gene, response to climate-change, and mtDNA transcription in absence of interspersed tRNA genes of octocoral mitochondrial genome. In order to put the observed novelties in the octocoral mitochondria in an evolutionary and an environmental context, and to understand their potential functions and the consequences of their presence in conferring fitness during climate change induced stress, this study was undertaken. This dissertation aims to explore the uniqueness and diversity of octocoral mtDNA from an environmental as well as an evolutionary perspective. The thesis comprises five chapters exploring various facets of octocoral biology. The introductory section provides basic information and elaborates on the importance of studying non-bilaterian mitochondria. The first chapter sets the base for subsequent gene expression studies. Octocorals are extensively studied from a taxonomic and phylogenetic point of view. However, gene expression studies on these organisms have only recently started to appear. To successfully employ the most commonly used gene expression profiling technique i.e., the quantitation real-time PCR (qPCR), it is necessary to have an experimentally validated, treatment-specific set of stably expressed reference genes that will support for the accurate quantification of changes in expression of genes of interest. Hence, seven housekeeping genes, known to exhibit constitutive expression, were investigated for expression stability during simulated climate-changed (i.e. thermal and low-pH) induced stress. These genes were validated and subsequently used in gene expression studies on Sinularia cf. cruciata, our model octocoral. The occurrence of a mismatch repair gene, and the slow rates of mtDNA evolution in octocoral mitogenome calls for further investigations on the potential robustness of octocoral mitochondria to the increased oxidative stress. The second chapter presents a mitochondrion-centric view of climate-change stress response by investigating mtDNA damage, repair, and copy number dynamics during stress. The changes in gene expression of a set of stress-related nuclear, and mitochondrial genes in octocorals were also monitored. A robust response of octocoral mitochondria to oxidative mtDNA damage was observed, exhibiting a rapid recovery of the damaged mtDNA. The stress-specific regulation of the mtMutS gene was detected, indicating its potential involvement in stress response. The results highlight the resilience potential of octocoral mitochondria, and its adaptive benefits in changing oceans. The tRNA genes in animal mitochondria play a pivotal role in mt-mRNA processing and maturation. The influence of paucity of tRNA genes on transcription of the mitogenome in octocorals has not been investigated. The third chapter steps in the direction to understand the mitogenome transcription by investigating the nature of mature mRNAs. Several novel features not present in a “typical” animal mt-mRNAs were detected. The majority of the mitochondrial transcripts were observed as polycistronic units (i.e. the mRNA carrying information for the synthesis of more than one protein). 5’ and 3’ untranslated regions were delineated for most protein-coding genes. Alternative polyadenylation (APA) of mtMutS gene and long non-coding RNA (lncRNA) for ATP6 were detected and are reported for the first time in non-bilaterian metazoans providing a glimpse into the complexity and uniqueness of mtDNA transcription in octocorals. The mismatch repair (MMR) mechanism plays a crucial role in mutation avoidance and maintenance of genomic integrity. Its occurrence in animal mitochondria remains equivocal. Octocorals are the only known animals to posses an mtDNA-encoded MMR gene, the mtMutS, speculated to have self-contained DNA repair capability. In order to gain knowledge of the MMR activity in the octocoral mitochondria MMR assays using the octocoral mitochondrial fraction is necessary. A prerequisite for this assay is the availability of an MMR-substrate, which is a DNA fragment, usually a plasmid, containing the desired mismatch lesion (i.e. a heteroduplex) and a nicked strand. However, the methods to prepare such a substrate are time consuming and technically demanding. Chapter four describes two convenient and flexible strategies that can be used in parallel to prepare heteroduplex MMR substrate using a common plasmid and routine molecular biology techniques. This method should aid in MMR investigations in general, helping to advance this field of research. The mtMutS gene mentioned above is a bacterial homolog, predicted to have been horizontally transferred to the octocoral mitogenome. However, unlike the bacterial mutS, which is extensively studied, protein expression studies of the octocoral mtMutS gene are lacking. To investigate the biological role of the mtMutS protein, in vitro, and to gain knowledge on its structure and function, the expression of the gene in a bacterial host is necessary. The fifth chapter discusses the characteristics of the mtMutS protein, the efforts to express it in E. coli and some necessary precautions to be taken while working with the expression of such mtDNA-encoded proteins for the research in future. This dissertation elucidates and contributes to the understanding of the unexplored complexity of non-bilaterian mitochondria. It deals for the first time with DNA repair, gene expression and gene function, encompassing an integrative analysis of DNA, RNA and proteins to achieve its goals. This study forms the basis for many future investigations on the molecular mitochondrial biology of octocorals as well as other non-bilaterians, augmenting the understanding of the evolution of animal mitochondria, and also its role in cellular and organismal homeostasis in the context of environmental change.

Someday in 2007, the world population reached a historical landmark: for the first time in human history, more than half of the world´s population was urban. A stagnation of this urbanization process is not in sight, so that by 2050, already 70 percent of humankind is projected to live in urban settlements. Over the last few decades, enormous migrations from rural hinterlands to steadily growing cities could be witnessed coming along with a dramatic growth of the world’s urban population. The speed and the scale of this growth, particularly in the so called less developed regions, are posing tremendous challenges to the countries concerned as well as to the world community. Within mega cities the strongest trends and the most extreme dimensions of the urbanization process can be observed. Their rapid growth results in uncontrolled processes of fragmentation which is often associated with pronounced poverty, social inequality, socio-spatial and political fragmentation, environmental degradation as well as population demands that outstrip environmental service capacity. For the majority of the mega cities a tremendous increase of informal structures and processes has to be observed. Consequentially informal settlements are growing, which represent those characteristic municipal areas being subject to particularly high population density, dynamics as well as marginalization. They have quickly become the most visible expression of urban poverty in developing world cities. Due to the extreme dynamics, the high complexity and huge spatial dimension of mega cities, urban administrations often only have an obsolete or not even existing data basis available to be at all informed about developments, trends and dimensions of urban growth and change. The knowledge about the living conditions of the residents is correspondingly very limited, incomplete and not up to date. Traditional methods such as statistical and regional analyses or fieldwork are no longer capable to capture such urban process. New data sources and monitoring methodologies are required in order to provide an up to date information basis as well as planning strate¬gies to enable sustainable developments and to simplify planning processes in complex urban structures. This research shall seize the described problem and aims to make a contribution to the requirements of monitoring fast developing mega cities. Against this background a methodology is developed to compensate the lack of socio-economic data and to deduce meaningful information on the living conditions of the inhabitants of mega cities. Neither social science methods alone nor the exclusive analysis of remote sensing data can solve the problem of the poor quality and outdated data base. Conventional social science methods cannot cope with the enormous developments and the tremendous growth as they are too labor-, as well as too time- and too cost-intensive. On the other hand, the physical discipline of remote sensing does not allow for direct conclusions on social parameters out of remote sensing images. The prime objective of this research is therefore the development of an integrative approach − bridging remote sensing and social analysis – in order to derive useful information about the living conditions in this specific case of the mega city Delhi and its inhabitants. Hence, this work is established in the overlapping range of the research topics remote sensing, urban areas and social science. Delhi, as India’s fast growing capital, meanwhile with almost 25 million residents the second largest city of the world, represents a prime example of a mega city. Since the second half of the 20th century, Delhi has been transformed from a modest town with mainly administrative and trade-related functions to a complex metropolis with a steep socio-economic gradient. The quality and amount of administrative and socio-economic data are poor and the knowledge about the circumstances of Delhi’s residents is correspondingly insufficient and outdated. Delhi represents therefore a perfectly suited study area for this research. In order to gather information about the living conditions within the different settlement types a methodology was developed and conducted to analyze the urban environment of the mega city Delhi. To identify different settlement types within the urban area, regarding the complex and heterogeneous appearance of the Delhi area, a semi-automated, object-oriented classification approach, based on segmentation derived image objects, was implemented. As the complete conceptual framework of this research, the classification methodology was developed based on a smaller representative training area at first and applied to larger test sites within Delhi afterwards. The object-oriented classification of VHR satellite imagery of the QuickBird sensor allowed for the identification of five different urban land cover classes within the municipal area of Delhi. In the focus of the image analysis is yet the identification of different settlement types and amongst these of informal settlements in particular. The results presented within this study demonstrate, that, based on density classes, the developed methodology is suitable to identify different settlement types and to detect informal settlements which are mega urban risk areas and thus potential residential zones of vulnerable population groups. The remote sensing derived land cover maps form the foundation for the integrative analysis concept and deliver there¬fore the general basis for the derivation of social attributes out of remote sensing data. For this purpose settlement characteristics (e.g., area of the settlement, average building size, and number of houses) are estimated from the classified QuickBird data and used to derive spatial information about the population distribution. In a next step, the derived information is combined with in-situ information on socio-economic conditions (e.g., family size, mean water consumption per capita/family) extracted from georeferenced questionnaires conducted during two field trips in Delhi. This combined data is used to characterize a given settlement type in terms of specific population and water related variables (e.g., population density, total water consumption). With this integrative methodology a catalogue can be compiled, comprising the living conditions of Delhi’s inhabitants living in specific settlement structures – and this in a quick, large-scaled, cost effective, by random or regularly repeatable way with a relatively small required data basis.The combined application of remotely sensed imagery and socio-economic data allows for the mapping, capturing and characterizing the socio-economic structures and dynamics within the mega city of Delhi, as well as it establishes a basis for the monitoring of the mega city of Delhi or certain areas within the city respectively by remote sensing. The opportunity to capture the condition of a mega city and to monitor its development in general enables the persons in charge to identify unbeneficial trends and to intervene accordingly from an urban planning perspective and to countersteer against a non-adequate supply of the inhabitants of different urban districts, primarily of those of informal settlements. This study is understood to be a first step to the development of methods which will help to identify and understand the different forms, actors and processes of urbanization in mega cities. It could support a more proactive and sustainable urban planning and land management – which in turn will increase the importance of urban remote sensing techniques. In this regard, the most obvious and direct beneficiaries are on the one hand the governmental agencies and urban planners and on the other hand, and which is possibly the most important goal, the inhabitants of the affected areas, whose living conditions can be monitored and improved as required. Only if the urban monitoring is quickly, inexpensively and easily available, it will be accepted and applied by the authorities, which in turn enables for the poorest to get the support they need. All in all, the listed benefits are very convincing and corroborate the combined use of remotely sensed and socio-economic data in mega city research.

Sponges are simple animals that mostly inhabit the marine ecosystem. The role of sponges in the marine ecosystem and the potential of their bioactive compounds for the pharmaceutical industry have already been reviewed. Because of the extensive investigations of sponges within those two disciplines, marine ecology and chemistry, sponges are among the best-studied Metazoa. Likewise, sponges have been selected as animal models for investigating the origin of the multicellularity because sponges have a simple body structure and physiology (e.g., lack of nervous and circulatory organs). Due to their diversity and abundance in the tropics, particularly in the Indo-Pacific, sponges have also attracted taxonomists, systematists and ecologists to assess their diverseness and their phylogenetic and phylogeographic relationships. Resolving those research questions is difficult, because sponges are categorised as comparatively character poor taxa. By using only conservative taxonomy or systematics, the sponge diversity might therefore be underestimated. Inevitably, sponge biologists have to employ molecular methods as additional tools. In this research, molecular tools were used in order to analyse the taxonomy, phylogeny and phylogeographic relationships of selected sponge species. Xestospongia testudinaria & Neopetrosia exigua (Family Petrosiidae, Order Haplosclerida) were selected because of their conspicuousness in the Indo-Pacific coral reef ecosystems, whereby Xestospongia testudinaria is prominently known as the Indo-Pacific giant barrel sponge. Additionally, the order Haplosclerida has been described as an example of sponge order that has been examined systematically for a number of years and displays major discrepancy between morphology and molecular phylogenies. Molecular data suggests that the order needs revision at all taxonomic levels, which is the cause for further conflicts between taxonomists and systematists. In my research I focused mostly on sponge samples that originated from South East Asia or the Indo-Australian Archipelago (IAA). This region represents one of the best-explored marine regions in the Indo-Pacific. The aim of my research is to discover to what extent molecular tools are suitable to detect a phylogenetic signal, a phylogeographical break or a genotypic difference in the two selected sponge taxa. Several markers from the mitochondrial (mtDNA), ribosomal (rRNA) and nuclear (nucDNA) have been utilised. The 3' partition of the cytochrome oxidase subunit 1 (I3-M11 of cox1) from the mtDNA could be used to detect a genetic structure in Xestospongia testudinaria in a geographical narrow scale study of < 200 km2 in Lembeh, North Sulawesi, Indonesia (Chapter 6) and throughout the Indo-Pacific despite limitations in the sample datasets (Chapter 2). In addition, the presence of a species complex in X. testudinaria was detected with the aid of phylogenetic reconstructions from a concatenation of mtDNA sequences (I3-M11 of cox1 and the Adenosine Triphosphate Synthase F0 subunit 6 / ATP6), and a nucDNA marker, the Adenosine Triphosphate Synthase β subunit intron (ATPS-β intron) (Chapter 6). At the same time, the presence of a species complex in X. testudinaria was recognised in a broader scale study of the Indo-Australian Archipleago (IAA) (Chapter 3). As a result, selected mtDNA and nucDNA markers in this thesis are useful for the investigation of the taxonomical status and phylogeographical relationships of X. testudinaria. A phylogeographical break in the IAA region due to the Pleistocene low sea level and Holocene recolonisation events (Chapter 3) could not be recovered among X. testudinaria in a phylogeographical analysis. Similarly, overlapping I3-M11 cox1 haplotypes between X. testudinaria, X. muta and X. bergquistia were recovered. This might be due to the presence of ancient polymorphisms on the barrel sponge mtDNA markers. Molecular tools are also used to help identifying my second selected sponge species (Chapter 4). The use of selected cox2 mtDNA and 28S rRNA markers contributed significantly to the identification of. Neopetrosia exigua used to be a congeneric of X. testudinaria. During my examinations of self-collected and holotype specimens I discovered that the species named N. exigua bears a wrong name. For this reason, a taxonomical revision is suggested and, more importantly, according to my findings and the principle of priority in the ICZN (International Code of Zoological Nomenclature) I use the species name ‘chaliniformis’ instead of the species name ‘exigua’. Furthermore, the use of selected nucDNA marker, the Lysidyl Aminoacyl Transfer RNA Synthetase (LTRS) intron, also contributes to the detection of phylogeographical breaks in N. chaliniformis of the IAA (Chapter 5). In a nutshell, the success of unravelling sponge taxonomies, phylogenies, and phylogeographic relationships always depends on the suitability of the utilised molecular markers and the significance of environmental influences on the sponges. Haplosclerid sponges possess limited morphological features. These hurdles create several problems, e.g. difficulties with taxa delimitation and unresolved phylogeography relationships. Even though the application of molecular techniques generated some limitations and obstacles in these studies, it has already contributed significantly to a better understanding of the phylogenies, phylogeographic relationships and taxonomical problems of X. testudinaria and N.chaliniformis, the species I selected for my research.

Explosive volcanism is one of the most catastrophic material failure phenomena. During magma ascent, fragmentation produces particulate magma, which, if deposited above the glass transition of the interstitial melt, will sinter viscously. In-conduit tuffisites, conduit wall breccias and ash deposited from exceptionally hot pyroclastic flows are scenarios in which sintering by viscous flow is possible. Therefore, understanding the kinetics of sintering and the characteristic timescales over which magma densifies are critical to understanding the degassing timeframe in conduits and deposits. Viscous sintering is accompanied by a recovery of material strength towards that of a pore-free, dense magma. Understanding damage mechanisms and seismic behaviour prior to failure of sintered volcanic products are also crucial for the application of micromechanical models and material failure forecasting laws. Powdered standard glass and industrial glass beads have been used to explore sintering mechanisms at ambient pressure conditions and temporal evolution of connected and isolated pore-structure. I observe that sintering under low axial stress is essentially particle size, surface tension and melt viscosity controlled. I found that the timescales over which the bulk density approaches that of a pore-free melt at a given temperature is dependent on the particle-contact surface area, which can be estimated from the particle shape, the packing type and the initial total porosity. Granulometric constraint on the starting material indicates that the fraction of finer particles controls the rate of sintering as they cluster in pore spaces between larger particles and have a higher driving force for sintering due to their higher surface energy to volume ratio. Consequently, the resultant sample suite has a range of microstructures because the viscous sintering process promotes a fining of pores and a coarsening of particles. In a volcano, newly formed sintering material will then further contribute to magma-plugging of the conduit and its mechanical properties will affect magma rupture and its associated precursory signals. This consideration permitted me to explore the effect of sintering on the stress required for dynamic macroscopic failure of synthesised samples and assess the ability of precursory microseismic signals to be used as a failure forecast proxy at conditions relevant to shallow volcanic conduits. To this end, the samples were subjected to mechanical tests under a constant rate of deformation and at a temperature in the region of the material glass transition. A dual acoustic emission rig was employed to track the occurrence of brittle fracturing. The monitored acoustic dataset was then exploited to systematically assess the accuracy of the failure forecasting method as a function of heterogeneity (cast as porosity) since it acts as nucleating site for fracture propagation. The pore-emanating crack model describes well the peak stress at failure in the elastic regime for these materials. I show that the failure forecast method predicts failure within 0-15% error at porosities >0.2. However, when porosities are <0.2, the forecast error associated with predicting the failure time increases to >100%. I interpret these results as a function of the low efficiency with which strain energy can be released in the scenario where there are few or no heterogeneities from which cracks can propagate. These observations shed light on questions surrounding the variable efficacy of the failure forecast method applied to active volcanoes. In particular, they provide a systematic demonstration of the fact that a good understanding of material properties is required. Thus I wish to emphasise the need for a better coupling of empirical failure forecasting models with mechanical parameters, such as failure criteria for heterogeneous materials, and point to the implications of this for a broad range of material-based disciplines.

This dissertation explores the effects of pressure on the magnetic remanence of iron-nickel and iron-silicon alloys relevant to the solid inner cores of the terrestrial planets and Earth’s moon. The Earth’s inner core likely comprises mostly pure iron in a hexagonal close packed (hcp) structure. Experiments on pure iron powder and foil were carried out up to 21 GPa at room temperature. The most important conclusion from this work is that either hcp-iron is ferromagnetic or that a poorly understood, intermediate hcp phase of iron is ferromagnetic. It was also determined that the results must be corrected for magnetic shape anisotropy, which is related either to the original sample material (foil) or how the bulk sample volume changes shape due to increasing oblateness of the chamber during pressurization. Fe-Ni alloys in the face centered cubic (fcc) phase with compositions around Fe64Ni36, called Invar, exhibit near-null thermal expansion, making them useful for technological applications. Models explaining the Invar effect evoke magnetovolume effect that compensate for thermal expansion. Previous work suggested that the Curie temperature of Fe64Ni36 decreases 35 K per GPa, which predicts that around 5 GPa, Fe64Ni36 will turn paramagnetic. Our experiments on Fe64Ni36 found a marked decrease in magnetization between 5-7 GPa, consistent with former studies, but that it remains ferromagnetic until 16 GPa. The magnetic remanence of low Ni Invar alloys increases faster with pressure than for other body-centered-cubic compositions due to the higher magnetostriction of the low Ni Invar metals. Experimental results on body centered cubic (bcc) Fe-Ni alloys match well with those for pure iron-- again leading to the conclusion that either an intermediate hcp phase, or that the hcp phase itself, is ferromagnetic. The ubiquitous enhancement in magnetization under pressure, or during pressure release, of the Fe-Ni and Fe-Si alloys is associated with strain-induced martensitic effects. Finally, a defocused laser heating technique was developed to measure the Curie temperature in diamond or moissanite anvil cells. Preliminary results on titanomagnetite (Fe2.4Ti0.6O4) are broadly consistent with previous work.

Bereits zu Beginn des 20. Jahrhunderts entwickelte Alfred Wegener seine allgemein bekannte Rekonstruktion der Kontinente, indem er die Fragmente kontinentaler Kruste durch Schließung der großen Ozeane entlang ihrer heutigen Küstenlinien zusammenfügte, so dass alle Kontinente zu einer Landmasse vereint waren. Den resultierenden Superkontinent nannte er "Pangäa" (Wegener, 1920). In dieser Rekonstruktion liegen sich Nord- und Südamerika gegenüber und Nordwestafrika grenzt an die Südostküste Nordamerikas. Lange Zeit nahm man an, dass die Paläogeographie dieses Superkontinents sich im Laufe seiner Existenz nicht bedeutend verändert hat, sondern dass die Kontinente sich im Jura im Wesentlichen aus der gleichen Konfiguration heraus voneinander gelöst haben, zu der sie sich ursprünglich im Paläozoikum zusammengefunden hatten. In der Tat gibt es vielfältige geologische, paläontologische und geophysikalische Hinweise dafür, dass Wegeners Pangäa-Konfiguration von der späten Trias bis in den frühen Jura Bestand hatte. In den späten Fünfzigerjahren des vergangenen Jahrhunderts entwickelte sich mit der Paläomagnetik eine Methode, die es ermöglicht, die Bewegungen der Kontinente über das Alter des ältesten bekannten Ozeanbodens hinaus zu rekonstruieren. Aufgrund des Dipolcharakters des Erdmagnetfeldes gilt das jedoch nur für die Rekonstruktion von paläogeographischen Breitenlagen, die Lage bezüglich der Längengrade kann mit Hilfe des Erdmagnetfeldes nicht eindeutig bestimmt werden. Eine nicht unerhebliche Anzahl paläomagnetischer Studien hat gezeigt, dass Wegeners Pangäarekonstruktion, auch Pangäa A genannt, mit globalen paläomagnetischen Daten in prä-triassischer Zeit nicht kompatibel ist. Zwingt man die Nord- und Südkontinente Pangäas, Laurasia und Gondwana für diese Zeit in die Pangäa A Konfiguration, so ergibt die auf paläomagnetischen Daten basierende paläogeographische Rekonstruktion ein signifikantes Überlappen kontinentaler Krustenanteile (siehe z. B. Van der Voo (1993); Muttoni et al. (1996, 2003) und darin zitierte Werke). Ein solches Überlappen lässt sich jedoch mit grundlegenden geologischen Prinzipien nicht vereinen. Im Lauf der Jahrzehnte wurden vielfältige alternative prä-triassische paläogeographische Pangäarekonstruktionen erstellt, die im Einklang mit den paläomagnetischen Daten sind. Der Hauptunterschied im Vergleich dieser Rekonstruktionen zur klassischen Pangäa A Konfiguration liegt in der Lage der Südkontinente relativ zu den Nordkontinenten. Um den kontinentalen Überlapp zu vermeiden, werden die Südkontinente unter Beibehaltung ihrer Breitenlage um ca. 30 Längengrade relativ zu den Nordkontinenten weiter im Osten platziert, so dass Nordwestafrika gegenüber Europa zu liegen kommt (Pangäa B, Irving (1977)). Da - wie erwähnt - der Dipolcharakter des Erdmagnetfeldes keine Aussagen über die Position der Kontinente bezüglich der Längengrade zulässt, ist dies mit den paläomagnetischen Daten vereinbar. Die alternativen Konfigurationen müssen jedoch alle vor dem Auseinanderbrechen Pangäas im Jura wieder in die für diesen Zeitraum allgemein akzeptierte Wegener-Konfiguration zurückgeführt werden. Dies geschieht - wiederum im Einklang mit den paläomagnetischen Daten - unter Beibehaltung der Breitenlage der Kontinente entlang einer postulierten kontinentalen dextralen Scherzone. Der Versatz von 2000 bis 3000 km fand laut Muttoni et al. (2003) in einem Zeitraum von ca. 20 Ma im frühen Perm statt. Dadurch ergibt sich eine entsprechend hohe Versatzrate von 10 bis 15 cm/a. Diese Arbeit befasst sich im Rahmen mehrerer paläomagnetischer Studien mit der Suche nach dieser großen Scherzone, deren Existenz seit Jahrzehnten umstritten ist. Der große Versatz wurde vermutlich von mehreren Störungssegmenten aufgenommen, die eine mehrere hundert Kilometer breite diffuse und segmentierte Scherzone bildeten. Paläogeographische Rekonstruktionen legen nahe, dass die Scherzone unter Anderem den Bereich des heutigen Mittelmeerraumes umfasst hat (Arthaud and Matte, 1977). Die Tizi-N'-Test-Verwerfung und ihre westliche Fortsetzung, die Süd-Atlas-Störung, sowie Verwerfungen entlang der nördlichen Pyrenäen und innerhalb des Armorikanischen Massivs (Bretagne) bilden demnach die Hauptblattverschiebungssysteme, die die Scherzone begrenzen. Krustenblöcke, die in entsprechend großen Störungssystemen liegen, können um vertikale Achsen rotieren (Nelson and Jones (1987) und darin zitierte Werke). Diese Rotationen können mit Hilfe der Paläomagnetik quantifiziert werden. Kapitel 1 leitet in die vorstehend beschriebene Problematik ausführlich ein und beleuchtet insbesondere die einzelnen Abschnitte dieser Arbeit. Somit wird deutlich, wie die Ergebnisse der Studien, aus denen sich die vorliegende Arbeit zusammensetzt, aufeinander aufbauen und einen konsistenten Lösungsansatz für die eingangs beschriebene Diskrepanz zwischen den Polwanderkurven Laurasias und Gondwanas entwickeln. Kapitel 2 beschreibt eine paläomagnetische Studie, die im Toulon-Cuers Becken, Südfrankreich durchgeführt wurde. Das Toulon-Cuers Becken entstand während einer Phase der Extension im südlichen variszischen Gürtel Europas, und ist sukzessive mit Sedimenten verfüllt worden. Außer mächtigen permo-triassischen Sedimentpaketen finden sich hier auch Laven und Pyroklastika als Produkte eines extensionsgetriggerten Vulkanismus, die ebenfalls Gegenstand der hier durchgeführten Studie sind. Die Ergebnisse der Untersuchungen können sehr gut mit bereits vorhandenen Literaturdaten in Einklang gebracht werden und zeigen, dass es zur fraglichen Zeit durchaus Bewegungen zwischen klar definierten Krustenblöcken gab, die Zeugen einer generellen Mobilität der Kruste in diesem Bereich sind. Es handelt sich hierbei um Blockrotationen um vertikale Achsen, so wie sie im Spannungsfeld einer kontinentalen Transformstörung zu erwarten sind. Dabei werden Rotationen im und gegen den Uhrzeigersinn dokumentiert, woraus eine komplexe Geometrie und Anordnung der Krustenblöcke abgeleitet werden kann. Hieraus wird ein tektonisches Modell entwickelt, welches mit gängigen Modellen (siehe McKenzie and Jackson (1983) in Nelson and Jones (1987)) in Einklang gebracht wird. Die triassischen paläomagnetischen Daten aus dem Gebiet belegen im Gegensatz dazu keine Rotationen und legen daher den Schluss nahe, dass die Krustenmobilität in dem Bereich zu Beginn des Mesozoikums zum Erliegen gekommen war. Somit belegt diese Studie deutlich, dass es im von Muttoni et al. (2003) postulierten zeitlichen Rahmen Hinweise für eine generelle Mobilität innerhalb Pangäas gibt. Unter Berücksichtigung dieser Ergebnisse wurde die folgende Studie an magmatischen Ganggesteinen ("Dykes") in Sardinien (Italien) durchgeführt, um die laterale räumliche Dimension der Scherzone besser abschätzen zu können. Kapitel 3 stellt die Ergebnisse dieser Studie vor. Die Dykes treten schwarmförmig auf und sind in einem Zeitraum zwischen 298 ± 5Ma und 270 ± 10Ma in den Korsika-Sardinien-Batholith intrudiert (Atzori and Traversa, 1986; Vaccaro et al., 1991; Atzori et al., 2000). Zusätzlich zu den Rotationen, die auch hier mittels paläomagnetischer Daten nachgewiesen werden konnten, gibt die Orientierung der einzelnen Dykeschwärme Aufschluss über das tektonische Spannungsfeld, das während der Platznahme der Dykes vorherrschte. Diese kombinierten Ergebnisse bestätigen und ergänzen die Ergebnisse der vorhergehenden Studie in Südfrankreich. Ergänzend zu den Untersuchungen an den Ganggesteinen Sardiniens werden Daten von permischen Sedimenten und Vulkaniten präsentiert, die in verschiedenen Regionen Sardiniens beprobt wurden (Kapitel 4). Die paläomagnetischen Daten belegen, dass Sardinien in mindestens zwei Krustensegmente zerlegt war, welche relativ zueinander und auch relativ zur europäischen Polwanderkurve rotiert sind. Auch hier wiederholt sich das Muster von Rotationen im und gegen den Uhrzeigersinn. In dieser Studie werden die Ergebnisse aus den vorangehenden Kapiteln sowie aus der weiterführenden Literatur zusammengefasst, so dass ein zeitlich und räumlich verfeinertes Bild der Krustenblöcke im westlichen Mittelmeerraum zur Zeit des frühen Perm entsteht. Durch die verbesserte Definition der Geometrie der einzelnen Blöcke kann das in Kapitel 2 beschriebene tektonische Modell bestätigt werden. Kapitel 5 befasst sich abschließend mit dem zeitlichen Rahmen der Aktivität entlang der fraglichen Scherzone. Ausgehend von der Annahme, dass sich die Kontinente im Jura bereits in einer Pangäa A Konfiguration befunden haben, sollten die paläomagnetischen Daten von jurassischen Gesteinen keine Hinweise auf Scherbewegungen geben. Hierzu wird eine Studie an jurassischen Sedimenten Sardiniens vorgestellt. Die paläomagnetischen Daten der untersuchten Krustensegmente belegen, dass es in post-jurassischer Zeit in Sardinien keine Blockrotationen der einzelnen Segmente relativ zueinander gab und Sardinien somit ab jener Zeit als tektonisch einheitlicher Block behandelt werden muss. Des Weiteren zeigen die paläomagnetischen Pole, die aus den paläomagnetischen Richtungen für eine Referenzlokalität berechnet wurden, keine signifikante Abweichung von der Polwanderkurve des europäischen Kontinents nach Besse and Courtillot (2002). Diese Kohärenz der paläomagnetischen Daten bestätigt die weithin akzeptierte Beobachtung, dass sich Pangäa zur Zeit des Jura bereits in der Wegener Konfiguration (Pangäa A) befunden hat und untermauert die Aussagekraft paläomagnetischer Studien in diesem Zusammenhang. Zugleich kann anhand dieser Daten ausgeschlossen werden, dass die alpidische Orogenese die Ursache für bedeutende Krustenblockrotationen in dieser Region gebildet hat. Die Ergebnisse der oben genannten Studien werden in dieser Arbeit zusammengeführt. Im Verbund mit Daten aus der Literatur untermauern sie, dass es zwischen dem frühen Perm und der frühen Trias entlang eines ausgedehnten Gürtels, der mindestens vom französischen Zentralmassiv über Südfrankreich bis nach Korsika- Sardinien reichte, bedeutende Krustenbewegungen in Form von Blockrotationen innerhalb Pangäas gab. Die vorliegende Synthese schafft somit ein konsistentes Bild der generellen Krustenmobilität zwischen den nördlichen Teilen Pangäas (Laurasia) und den Südkontinenten (Gondwana). Der durch die präsentierten Studien abgesteckte zeitliche Rahmen korreliert mit den Abschätzungen von Muttoni et al. (2003) zur Transformation zwischen verschiedenen Pangäakonfigurationen. Diese Arbeit bestätigt außerdem, dass das mittlere Perm eine Zeit großräumiger Reorganisation der kontinentalen Platten war, die von anhaltender magmatischer Aktivität begleitet war (Deroin and Bonin, 2003; Isozaki, 2009). Anhand der hier vorgestellten neuen Daten in Kombination mit bereits bekannten paläomagnetischen Daten aus der Region ergibt sich ein klares Muster von Rotationen im und gegen den Uhrzeigersinn von einzelnen störungsbegrenzten Krustenblöcken. Diese Arbeit belegt, dass die Paläomagnetik ein hervorragendes Instrument zur Quantifizierung jener Krustenblockrotationen ist, die oftmals die einzigen verbleibenden Indizien für ehemals großräumige Scherzonen bieten, nachdem die Störungen selbst aufgrund vielfältiger Prozesse nicht mehr aufgeschlossen sind (Umhoefer, 2000). Die tektonischen Modelle von McKenzie and Jackson (1983) in der Interpretation nach Nelson and Jones (1987) werden als Erklärungsgrundlage für die beobachteten Rotationen herangezogen und erweitert.

Biological carbonate hard tissues, such as the shell of the bivalve Mytilus edulis, are composites of biopolymers and minerals. M. edulis has two distinct layers, the outer layer consists of fibrous calcite and the inner layer is composed of nacreous aragonite. Close to the interface between nacreous aragonite and fibrous calcite, a 1-2 micrometer wide zone exists that consists of granular aragonite. Aragonite granules and tablets as well as calcite fibrous are embedded into matrix biopolymers. In order to understand the composite nature of these hard tissues, biomimetic experiments using hydrogels were carried out. Hydrogels are able to model biogenic matrix environments due to their ability to confine space and to determine diffusion rates, local concentrations and supersaturation of the solutes. Hydrogels have local crystallization microenvironment that is distinguished from that in solution by confinement of solutes in the hydrogel pores. However, hydorgels only mimic biological extracellular matrices to some extent as the hydrogel fiber organization lacks any order, unlike it is in the case of the cholesteric liquid phase, e. g. chitin. The hydrogel strength is adjustable by changing its solid content. It further increases local hydrogel fiber co-aligments that to some extent will mimic organic matrices in biological hard tissues. Different kinds of hydrogels were used to study calcite crystallization (silica, agarose, gelatin). As each hydrogel has different characteristics, hydrogels can act differently in promoting or inhibiting crystallization. Hydrogels have an ability to mechanically impede the growth of a crystal depending on the strength of the hydrogel. Gelatin hydrogel is a poly-peptide material derived from natural collagen through hydrolytic degradation. The hyrolitic degradation breaks the triple-helix structure of collagen into single-strand molecules. Gelatin contains both acidic and basic amino acids with isoelectric point values near ∼5 and with predominance of acidic moieties. Agarose hydrogel is a linear polysaccharide extracted from marine red algae. It consists of beta-1,3 linked D-galactose and alpha-1,4 linked 3,6-anhydro-alpha-L-galactose residues. Gelatin and agarose hydrogels are composed of a fibrous structure that have varying mesh void dimensions depending on the hydrogel solid content. Hydrogel with 2.5 wt % gelatin solid content exerts less pressure against the growing calcite crystal aggregate than a hydrogel with 10 wt % gelatin solid content. Silica hydrogel does not exert strong pressure against the growing calcite crystal aggregate due to its nature as it is composed of minute (less than 20 nm) sized spherical particles that do not appear to form a network. The hydrogel strength together with the growth rate of the crystal defines the amount of incorporated hydrogel into the growing calcite crystal aggregate such that a strong hydrogel will incorporate more gel into the calcite crystal than a weak hydrogel. Calcite grown in Mg-free silica hydrogels has a rhombohedral shape and is elongated on the c-axis. It grows as dumbbell-shaped aggregates in the presence of Mg. Silica hydrogel either Mg-free or Mg-bearing does not give a major influence on the co-orientation of the obtained crystal aggregate. Calcite grown in Mg-free agarose has two morphologies: rhombohedron-shaped calcite crystals and calcite radial aggregates. Calcite grown in Mg-bearing agarose has sheaf-like and peanut like morphologies. The presence of Mg in agarose influences the co-orientation of calcite crystals within calcite Mg-bearing agarose composites. The calcite/Mg-free agarose composite has several large crystal subunits while the calcite/Mg-bearing agarose composite shows a spherulitic microstructure. In the case of gelatin hydrogel, the precipitate consists of calcite aggregates that have a variety of features i.e. the formation of mosaic crystals and mesocrystal-like subunits in one aggregate, the formation of aggregates with a fan-like distribution of the c-axis orientation and the formation of spherulitic aggregates. The formation of aggregates with different characteristic in the subunits can be explained as a result of a combination between local differences in gelatin matrix arrangement and physicochemical conditions such as the change in Mg/Ca ratio, pH, saturation, etc. The development of a fan-like distribution of the c-axes orientation in the calcite aggregate subunits can be explained as a result of Mg intrasectorial zoning. A different degree of Mg incorporation in different growth steps will accumulate misfit strain in the lattice. This misfit strain could be released through the formation of dislocations at regular intervals, such that small-angle boundaries develop. This growth further leads to the extreme split growth and the formation of fan-like and spherulitic crystal aggregates. The etching experiments of calcite/hydrogel composites reveal the structure of the incorporated hydrogel within the calcite crystals and aggregates. In the case of Mg-bearing silica hydrogel more silica hydrogel is incorporated into the calcite crystal than in the case of Mg-free silica hydrogel. Thick hydrogel membranes are observed when Mg-free gelatin and agarose hydrogels are used. These membranes do not occur when Mg is present. The formation of these membranes in Mg-free gelatin and agarose hydrogels is a result of an accumulation of the hydrogel fibers that are driven back by growing crystals or aggregates. The stiffness of the gelatin and agarose hydrogel fibers increase as Mg is added into the hydrogel. The hydrogel becomes stiffer and exerts more pressure against the growing aggregates. No hydrogel membranes are observed in aggregates grown in Mg-bearing gelatin and in agarose hydrogels. On the basis of biopolymer and mineral composites, gypsum (CaSO4)/cellulose fiber composites were prepared. The purpose of the addition of cellulose fiber to gypsum was to create a composite with a high ecological value and interesting mechanical properties such as high Young’s modulus, high bending strength and high compression strength. The cellulose fiber affects the mechanical property of the composites depending on the fiber characteristics, e.g. the nature of the cellulose (natural or synthetic), water retention value, degree of swelling, etc. Lyocell fiber, a synthetic fiber, is found to be able to increase the Young’s modulus of the final composite.

Problem. More than ever, some of the biggest challenges to society involve governance of natural resources. From large-scale resource systems such as the rain forest and oceans to small-scale systems such as lakes or alpine pastures, cooperative efforts are required to ensure sustainable and yet productive use of natural resources. In Switzerland, the management of alpine pastures has for centuries been predominantly organized by local governance institutions, avoiding an overuse of the scarce resources. During the past decade, the use and maintenance of common property pastures (CPP) is declining, leading to land abandonment and forest regrowth. However, CPP provide significant services to the mountain regions, such as additional grazing grounds, assets for the tourism industry, protection from soil erosion, water run-off and landslides, and high biodiversity. These services are currently threatened by reduced use and maintenance of the CPP. Research Aims. The research presented herein aims for a better understanding of social-ecological interactions driving the use of CPP to provide policy recommendations for the sustainable governance of CPP. Methods. To generate a holistic understanding of the variables driving CPP use, this research used multiple methods to investigate CPP use in Grindelwald, Switzerland as a social-ecological system (SES). The research was structured in 4 modules. First, qualitative methods were applied to analyze institutional change in the governance of CPP. Second, regression models were built from survey data to better understand farmers’ land-use decision. Third, an analysis of the ecological system was conducted bases on land-cover statistics. Forth, a systems dynamics model of the local SES was built and combined with formative scenario analysis to investigate potential future developments of CPP use. Results. The outcomes of the different modules suggest that: First, local governance systems originally designed to prevent overuse of CPP are able to adapt to problems of declining use and maintenance of CPP by altering a set of rules. Second, farmers’ use of CPP depend on personal attributes, including farm size, norms, and dependence on the resource. Furthermore, the analysis suggests that high local demand and prices for alpine cheese are a central factor in the sustainable use of CPP. Third, the land-cover analysis showed that afforestation occurs in Grindelwald at a relatively moderate pace and defines the area most prone to afforestation and bush encroachment. Fourth, the simulation model allows for the display of complex social-ecological interactions, showing that afforestation tendencies are likely to continue, although at different pace depending on the scenario setting. Conclusion. This research provides a better understanding of CPP use through the analysis of the subsystem characterizing the SES. It showed how the general framework for analyzing social-ecological systems can be operationalized using a broad set of methods. It thereby contributed and advanced central themes within the study of the commons such as institutional analysis, users’ behavior in cooperative dilemmas, and modeling of SES. The integration of the findings from different modules into a simulation provided insights about the effects of different policies on the sustainability of the SES, and thereby demonstrated why particular policy blueprints will rather accelerate than counteract the problem of CPP abandonment.

The Central Asian Orogenic Belt (CAOB) is one of the world's largest accretionary orogens, which was active during most of the Paleozoic. In recent years it has again moved into focus of the geological community debating how the acrreted lithospheric elements were geographical arranged and interacting prior and/or during the final amalgamation of Kazakhstania. In principal two families of competing models exist. One possible geodynmaic setting is based on geological evidence that a more or less continuous giant arc connecting Baltica and Siberia in the early Paleozoic was subsequently dissected and buckled. Alternatively an archipelago setting, similar to the present day south west Pacific was proposed. This thesis collates three studies on the paleogeography of the south western part of the CAOB from the early Paleozoic until the latest Paleozoic to earliest Mesozoic. It is shown how fragments of Precambrian to early Paleozoic age are likely to have originated from Gondwana at high southerly paleolatitudes (~500 Ma), which got then accreted during the Ordovician (~460 Ma), before this newly created terrane agglomerate (Kazakhstania) migrated northwards crossing the paleo-equator. During the Devonian and the latest Early Carboniferous (~330 Ma) Kazakhstania occupied a stable position at about ~30°N. At least since this time the area underwent several stages of counterclockwise rotational movements accompanying the final amalgamation of Eurasia (~320 - ~270 Myr). This overall pattern of roughly up to 90° counterclockwise bending was replaced by internal relative rotational movements in the latest Paleozoic, which continued probably until the early Mesozoic or even the Cenozoic. In Chapter 2 a comparison of declination data acquired by a remagnetization process during folding in the Carboniferous and coeval data from Baltica and Siberia lead to a documentation and quantification of rotational movements within the Karatau Mountain Range. Based on this results it is very likely that the rotational reorganization started in the Carboniferous and was active until at least the early Mesozoic. Additionally, the data shows that maximal declination deviation increases going from the Karatau towards the Tianshan Mountains (i.e. from North to South). This observation supports models claiming that Ural mountains, Karatau and Tianshan once formed a straight orogen subsequently bent into a orocline. The hinge of this orocline is probably hidden under the sediments of the Caspian basin. In chapter 3 we show that inclination shallowing has affected the red terrigenous sediments of Carboniferous age from the North Tianshan. The corrected inclination values put this part of the Tianshan in a paleolatitude of around 30°N during Carboniferous times. These results contradict previously published paleopositions of the area and suggest a stable latitudinal position between the Devonian and the Carboniferous. Chapter 4 presents paleomagnetic data from early Paleozoic rocks from within the North Tianshan. They imply a second collisional accretion event of individual terranes in the Ordovician. To further constrain the dimensions of these early Paleozoic terranes, chapter 5 presents a compilation of all available paleomagnetic data from the extended study region of southern Kazakhstan and Kyrgyzstan. Apart from a broad coherence of paleolatitudes of all studies at least since the Ordovician and the exclusive occurrence of counterclockwise declination deviations, no areas with the same rotational history can be detected. Also a clear trend caused by oroclinal bending can not be observed. We conclude that first order counterclockwise oroclinal bending, shown in chapter 2, resulted in brittle deformation within the mountain belt and local block rotations. In order to improve our understanding of intra-continental deformation a study combining the monitoring of recent deformation (Global Positioning System, GPS) with a paleomagnetic study of Cenozoic age in the greater vicinity of the Talas-Ferghana fault has been undertaken in chapter 6. The major task was to distinguish between continuous versus brittle deformation. As it turned out the GPS signal indicates rather continuous and consistent counterclockwise rotational movements of the order of ~2° per Myr. This is in contrast to our paleomagnetic results, where even within fault bounded areas the error intervals of the rotations do always overlap. This indicates that a pure block model seems not appropriate even to explain Cenozoic paleomagnetic data. If this means that also Paleozoic rocks have been affected by complex recent deformation, and that the Paleozoic rotational pattern has been obscured by this, can not be decided based on the present data set. It means, however, that interpreting Paleozoic rotational data from this area has to be done with great caution.

The scientific investigation of the solid Earth's complex processes, including their interactions with the oceans and the atmosphere, is an interdisciplinary field in which seismology has one key role. Major contributions of modern seismology are (1) the development of high-resolution tomographic images of the Earth's structure and (2) the investigation of earthquake source processes. In both disciplines the challenge lies in solving a seismic inverse problem, i.e. in obtaining information about physical parameters that are not directly observable. Seismic inverse studies usually aim to find realistic models through the minimization of the misfit between observed and theoretically computed (synthetic) ground motions. In general, this approach depends on the numerical simulation of seismic waves propagating in a specified Earth model (forward problem) and the acquisition of illuminating data. While the former is routinely solved using spectral-element methods, many seismic inverse problems still suffer from the lack of information typically leading to ill-posed inverse problems with multiple solutions and trade-offs between the model parameters. Non-linearity in forward modeling and the non-convexity of misfit functions aggravate the inversion for structure and source. This situation requires an efficient exploitation of the available data. However, a careful analysis of whether individual models can be considered a reasonable approximation of the true solution (deterministic approach) or if single models should be replaced with statistical distributions of model parameters (probabilistic or Bayesian approach) is inevitable. Deterministic inversion attempts to find the model that provides the best explanation of the data, typically using iterative optimization techniques. To prevent the inversion process from being trapped in a meaningless local minimum an accurate initial low frequency model is indispensable. Regularization, e.g. in terms of smoothing or damping, is necessary to avoid artifacts from the mapping of high frequency information. However, regularization increases parameter trade-offs and is subjective to some degree, which means that resolution estimates tend to be biased. Probabilistic (or Bayesian) inversions overcome the drawbacks of the deterministic approach by using a global model search that provides unbiased measures of resolution and trade-offs. Critical aspects are computational costs, the appropriate incorporation of prior knowledge and the difficulties in interpreting and processing the results. This work studies both the deterministic and the probabilistic approach. Recent observations of rotational ground motions, that complement translational ground motion measurements from conventional seismometers, motivated the research. It is investigated if alternative seismic observables, including rotations and dynamic strain, have the potential to reduce non-uniqueness and parameter trade-offs in seismic inverse problems. In the framework of deterministic full waveform inversion a novel approach to seismic tomography is applied for the first time to (synthetic) collocated measurements of translations, rotations and strain. The concept is based on the definition of new observables combining translation and rotation, and translation and strain measurements, respectively. Studying the corresponding sensitivity kernels assesses the capability of the new observables to constrain various aspects of a three-dimensional Earth structure. These observables are generally sensitive only to small-scale near-receiver structures. It follows, for example, that knowledge of deeper Earth structure are not required in tomographic inversions for local structure based on the new observables. Also in the context of deterministic full waveform inversion a new method for the design of seismic observables with focused sensitivity to a target model parameter class, e.g. density structure, is developed. This is achieved through the optimal linear combination of fundamental observables that can be any scalar measurement extracted from seismic recordings. A series of examples illustrate that the resulting optimal observables are able to minimize inter-parameter trade-offs that result from regularization in ill-posed multi-parameter inverse problems. The inclusion of alternative and the design of optimal observables in seismic tomography also affect more general objectives in geoscience. The investigation of the history and the dynamics of tectonic plate motion benefits, for example, from the detailed knowledge of small-scale heterogeneities in the crust and the upper mantle. Optimal observables focusing on density help to independently constrain the Earth's temperature and composition and provide information on convective flow. Moreover, the presented work analyzes for the first time if the inclusion of rotational ground motion measurements enables a more detailed description of earthquake source processes. The complexities of earthquake rupture suggest a probabilistic (or Bayesian) inversion approach. The results of the synthetic study indicate that the incorporation of rotational ground motion recordings can significantly reduce the non-uniqueness in finite source inversions, provided that measurement uncertainties are similar to or below the uncertainties of translational velocity recordings. If this condition is met, the joint processing of rotational and translational ground motion provides more detailed information about earthquake dynamics, including rheological fault properties and friction law parameters. Both are critical e.g. for the reliable assessment of seismic hazards.