ALBERT

Description: Der glazial-isostatische Ausgleich in Island infolge des rezenten Abschmelzens der Vatnajökull-Eiskappe wird durch die Viskositätsverteilung im Erdinnern und durch die Details der Abschmelzgeschichte kontrolliert. Interpretationen der Ergebnisse von GPS- und Schweremeßkampagnen im Zeitintervall 1991–2000 bzw. 1992–1999 mit Hilfe lateral homogener Erdmodelle zur Bestimmung der Lithosphärenmächtigkeit, Asthenosphärenmächtigkeit und Asthenosphärenviskosität sind bislang nicht voll zufriedenstellend gewesen. Insbesondere nahe des Eisrandes war die Anpassung der berechneten Landhebung und Schwereänderung an die Beobachtungsdaten nur unzureichend, was mit der Nichtberücksichtigung des Island-Plumes in den lateral homogenen Erdmodellen zusammenhängen kann. In der vorliegenden Arbeit wird für die Modellierung der Landhebung und Schwereänderung ein Programmpaket verwendet, daß die Berechnung auflastinduzierter Störungen eines Maxwellviskoelastischen, inkompressiblen, selbstgravitierenden, sphärischen Erdmodells gestattet. Um das Vorhandensein des Plumes unter dem Vatnajökull zu simulieren, wird eine axialsymmetrische Viskositätsverteilung verwendet, wobei der Plumeradius und die Plumeviskosität freie Parameter sind. Basierend auf seismischen Ergebnissen wird über dem Plume eine 6 km mächtige Lithosphäre angenommen, die sich im peripheren Bereich des Plumes auf 35 km verdickt. Die Abschmelzgeschichte des Vatnajökulls beruht auf Interpretationen geomorphologischer und klimatologischer Untersuchungen und wird durch eine mit dem Plume koaxiale Last mit parabolischem Profil und zeitabhängigem Radius simuliert. Die Ergebnisse der Modellierung favorisieren einen Plumeradius von ~ 80 km und eine Plumeviskosität von (0.3–1.0) × 1018 Pa s.

Description: The intention of this article is to present the definitions of different functionals of the Earth's gravity field and possibilities for their approximative calculation from a mathematical representation of the outer potential. [...] More or less, what is compiled here is well-known in physical geodesy but distributed over a lot of articles and books which are not cited here. In the first instance this text is targeted at non-geodesists and it should be "stand-alone readable".

Description: The final report contains a description of the results obtained within a research contract between IRE RAS and GFZ Potsdam during the period April-November 2004. The objectives of investigation included (1) the radio-holographic methods for obtaining vertical profiles of the vertical gradients of physical parameters in the atmosphere, (2) radio holographic methods for atmospheric, ionospheric and stratospheric waves, and (3) validation of the software with GPS/MET (GPS/METeorology, e.g., Rocken et al. 1997) and CHAMP (CHAllenging Minisatellite Payload, e.g., Reigber et al. 2005) data and final report with recommendations.

Description: Late Miocene to Quaternary volcanic rocks from the frontal arc to the back-arc region of the Central Volcanic Zone in the Andes show a wide range of delta 11B values (+4 to -7 ‰) and boron concentrations (6 to 60 ppm). Positive delta 11B values of samples from the volcanic front indicate involvement of a 11B-enriched slab component, most likely derived from altered oceanic crust, despite the thick Andean continental lithosphere, and rule out a pure crust-mantle origin for these lavas. The delta 11B values and B concentrations in the lavas decrease systematically with increasing depth of the Wadati-Benioff Zone. This across-arc variation in delta 11B values and decreasing B/Nb ratios from the arc to the back-arc samples are attributed to the combined effects of B-isotope fractionation during progressive dehydration in the slab and a steady decrease in slab-fluid flux towards the back arc, coupled with a relatively constant degree of crustal contamination as indicated by similar Sr, Nd and Pb isotope ratios in all samples. Modelling of fluid-mineral B-isotope fractionation as a function of temperature fits the across-arc variation in delta 11B and we conclude that the B-isotope composition of arc volcanics is dominated by changing delta 11B composition of B-rich slab-fluids during progressive dehydration. Crustal contamination becomes more important towards the back-arc due to the decrease in slab-derived fluid flux. Because of this isotope fractionation effect, high delta 11B signatures in volcanic arcs need not necessarily reflect differences in the initial composition of the subducting slab. Three-component mixing calculations for slab-derived fluid, the mantle wedge and the continental crust based on B, Sr and Nd isotope data indicate that the slab-fluid component dominates the B composition of the fertile mantle and that the primary arc magmas were contaminated by an average addition of 15 to 30 % crustal material.

Description: The striking improvements in long- to medium-wavelengths gravity field recovery achieved with GPS-CHAMP and GPS-GRACE high-low and GRACE K-band range low-low satellite-to-satellite tracking prompted us to combine the satellite data with surface data from altimetry over the oceans and gravimetry over the continents to generate a new, high resolution global gravity field model: EIGEN-CG01C. The model is complete to degree/order 360 in terms of spherical harmonics and resolves half-wavelengths of 55 km in the geoid and gravity anomaly fields. A special band-limited combination method has been applied in order to preserve the high accuracy from the satellite data in the lower frequency band of the geopotential and to allow for a smooth transition to the high-frequency band, dominated by the surface data. Compared to pre-CHAMP/GRACE global high-resolution gravity field models, the accuracy was improved by one order of magnitude to 4 cm and 0.5 mgal in terms of geoid heights and gravity anomalies, respectively, at a spatial resolution of 200 km half-wavelength. The overall accuracy at degree/order 360 is estimated to be 20 cm and 5 mgal, respectively, and benefits significantly from recently released new gravity anomaly compilations over the polar regions. In general, the accuracy over the oceans is better than over the continents reflecting the higher quality of the available surface data.

Description: Die im Norddeutschen Becken vorkommenden hochsalinaren, heißen Tiefenwässer besitzen ein beträchtliches Wärmepotential, das bisher in Neustadt-Glewe, Neubrandenburg und Waren zur Energiegewinnung genutzt wird. Das Ziel der vorliegenden Arbeit bestand zum einen darin, die Herkunft und die Genese dieser Solen und der in ihnen gelösten Stoffe zu rekonstruieren. Ein zweiter Schwerpunkt bestand in der Ermittlung geochemischer Parameter, die für einen problemlosen Langzeitbetrieb geothermischer Anlagen und somit für deren Wirtschaftlichkeit von Bedeutung sind. Die untersuchten Solen stammten aus Aquiferen, die durch fünf Bohrungen (Neubrandenburg, Waren, Rheinsberg, Neustadt-Glewe, Hamburg-Allermöhe) in Tiefen von 1250 bis 3250 m (54 bis l28°C) erschlossen wurden. Alle untersuchten Na-Cl-Solen wurden aus Sandsteinaquiferen des Keuper (Contorta!Postera-Schichten) gefördert, für die mit zunehmender Tiefe steigende TDS-Gehalte (134 bis 224 g/1) charakteristisch sind. Die Zusammensetzung der gelösten Feststoffe blieb über einen Zeitraum von 3 Jahren konstant. Die Br/CJ-Verhältnisse der Solen sind kleiner als in eingedampftem Meerwasser. Dies und 811B-Werte von +23.8 %o bis +36.3 %o indizieren die Herkunft des Salzgehaltes durch Auflösung/Laugung von Salzen. Das Gas-Wasser-Volumenverhältnis in Proben geothermisch genutzter Solen liegt bei max. 1:10. Die Gasphase wird von C02, N2 und CH4 dominiert, wobei der Gehalt an C02 und CH4 mit der Tiefe zunimmt. Als Spurengase treten He, Ar, H2 und weitere Kohlenwasserstoffe auf (jeweils 〈1 Vol.-%). Die Gasphase des Thermalwassers Neustadt-Giewe zeigte über einen Zeitraum von 2 Jahren keine Änderung in ihrer Zusammensetzung. Periodische Schwankungen in sehr kleinen Konzentrationsbereichen während einer mehrtägigen Gasmeßkampagne korrelieren mit den Erdgezeiten. Die N2-Ar-He-Verhältnisse zeigen, daß es sich um tiefzirkulierende Oberflächenwässer handelt. Untermauert wird diese Interpretation durch die sehr niedrigen 3HefHe-Verhältnisse (R!Ra:S;O.Ol), die keine Mantelheliumkomponente anzeigen, sowie die gegenüber Luft (295.5) leicht erhöhten 40 Ar/36 Ar-Verhältnisse von bis zu 367.5. He-Akkumulationsalter als scheinbare Verweildauer der Solen von 20 bis 50 Ma wurden berechnet. Das Tiefenwasser von NeustadtGiewe besaß gegenüber den anderen Lokationen erhöhte Kohlenwasserstoffgehalte. Die 813C1,2,3- Werte weisen auf thermogenetische Kohlenwasserstoffe und auf ein marines Ausgangsmaterial mit einer Reife, die einer Vitrinitreflektion von etwa 1.2 % entspricht, hin. Die Herkunft aus Corgreichen Zechstein-Sedimenten ist wahrscheinlich, organisches Material des wesentlich tiefer liegenden Karbons scheidet als Quelle aus. Die 8180- und öD-Werte der Wässer zeigen an, daß meteorisches Wasser bei der Genese eine bedeutende Rolle gespielt hat. Die ermittelte isatopische Zusammensetzung der meteorischen Komponente weicht von heutigen Niederschlagswässern ab und weist einen letztmaligen Kontakt mit der Atmosphäre zu einer Zeit deutlich wärmeren Klimas als das heutige nach. Die in einem Thermalwasser vorhandenen Gase können die technologische Eignung der Sole und den Betrieb einer geothermischen Anlage maßgeblich beinflussen (Scaling, Auftreten brennbarer Gase, Entlösung von Gasen). Bei Vorhandensein Corg-reicher Sedimente nimmt die Wahrscheinlichkeit des Auftretens brennbarer Gase in Wässern aus größerer Tiefe, die durch ihre höhere Temperatur wirtschaftlicher sind, zu. Um die Entgasung eines Tiefenwassers innerhalb einer Anlage zu verhindem und somit Scaling und unkontrolliertes Entgasen zu minimieren, wurde anhand Literaturdaten exemplarisch für den Thermalwasserkreislauf der Anlage Neustadt-Giewe (Sole mit den höchsten Gasgehalten) ein Mindestanlagendruck berechnet. Danach sind etwa 2 bar ausreichend, um ein Entgasen der Sole zu verhindern; Strömungseffekte erfordern jedoch eine Erhöhung des Anlagendrucks auf etwa 4 bar. Die zeitliche Konstanz in der Zusammensetzung der gelösten Feststoffe und der Gasphase über einen Zeitraum von 2 bzw. 3 Jahren zeugt von einer relativ großen räumlichen Homogenität der Aquifere, wodurch der Betrieb der Anlagen durch Änderungen in der chemischen Zusammensetzung der Solen kaum gefährdet zu sein scheint. Die Ergebnisse der vorliegenden Arbeit haben gezeigt, daß sowohl bei der hydrodynamischen Vorerkundung als auch während des Betriebes eines geothermischen Heizwerkes die genaue Kenntnis der Gasmengen und der Gaszusammensetzung von entscheidender Bedeutung ist.

Description: Deep seated hydrothermal brines in the North German Basin have a considerable heat potential, which is currently used for geothermal energy recovery in Neustadt-Glewe, Neubrandenburg and Waren. One aim of this study was to reconstruct the origin of these brines and their dissolved substances. Another goalwas to determine geochemical parameters which are critically influence the long-term operation, and hence the econornic viability of geothermal plants. The brines come from aquifers which have been accessed by 5 boreholes (Neubrandenburg, Waren, Rheinsberg, Neustadt-Glewe, Hamburg-Allermöhe) in depths from 1250 to 3250 m (54 to 128 °C). All investigated Na-Cl-brines were produced from sandstone aquifers of the Keuper (Contorta!Postera layers). Typically, TDS-values (134 to 224 g/1) increase with depth. The compositions of the dissolved solids were constant during 3 years. The Br/Cl ratios of the brines are lower than evaporated sea water. This, and 811B-values of +23.8 %o up to +36.3 %o indicate dissolution/leaching of salt as the origin of the salt content. The gas-water volume ratio of samples from brines used for geothermal energy recovery are less than around 1:10. The gas phase is dorninated by C02, N2 and C~ with higher C02- and C~ contents with increasing depths. He, Ar, H2 and other hydrocarbons exist as traces ( 〈1 vol.% each). The gas phase of the thermal water from Neustadt-Giewe showed no changes in its composition during 2 years. Small · periodical variations in the concentrations obtained from gas monitaring over several days correlate with the earth tides. The N2-Ar-He ratios show that the waters are deep-circulating meteoric waters. This interpretation is supported by very low 3HefHe ratios (R!Ra:S;O.Ol), which show no mantle helium, and 40 ArP6 Ar ratios up to 367.5, which are slightly enhanced compared to air (295.5). He accumulation ages, taken as the apparent residence time of the brines, were calculated to be 20 to 50 Ma. Compared to the other locations the formation water from Neustadt-Giewe contained enhanced hydrocarbon contents. The 813C1,2,3 values point to thermogenic hydrocarbons and to a marine source rock with a maturity corresponding to about 1.2 % vitrinite reflectivity. An origin from Corg-rich Zechstein sediments seems probable, organic material from significantly deeper-seated Carboniferous formations can be ruled out. The 8180 and ÖD values of the waters confirm that meteoric water played an important role in the brine genesis. The determined isotopic composition of the meteoric component deviates from recent precipitation and indicates a last contact with the atmosphere at a time when climate conditions were significantly warmer than today. Gases dissolved in thermal waters can significantly affect both the technological suitability of a brine and the operation of a geothermal heat plant (scaling, degassing, occurence of flammable gases). If Corg-rich sedimentary rocks occur, the probability of the occurence of flammable gases increases in waters from larger depths, which are more economic due to their higher temperature. The pressure needed to prevent degassing inside a plant and thus to rninirnize scaling and uncontrolled degassing was calculated for the example of the thermal water cycle at Neustadt-Giewe (brine with the highest gas content). About 2 bars are sufficient to prevent degassing; however, flow effects require increasing the pressure up to about 4 bars. The constant composition of both the dissolved solids and gases over a period of 2 to 3 years is a sign of a relatively large spatial uniformity of the aquifers. Therefore the continuous operation of the plants seems unlikely to be endangered by a change in the chernical composition of the brines. The results of this study have shown that during the hydrodynarnic reconnaissance as weil as during the operation of a geothermal heat plant, precise knowlegde of the gas concentration is of essential importance.

Description: The purpose of this study is to refine the probabilistic seismic hazard assessment for Vanuatu. The analysis is complicated by inconsistencies of the global and local data for the investigated region and systematic inadequacies of the attenuation relation available. An additional aspect in the field of which more research would be desirable is the de-clustering algorithm for the identification of dependent earthquakes. In order to quantify the inevitable uncertainties associated with our results, we used a Logic Tree approach. The report is subdivided into seven chapters. Chapter 2 summarises the geology and tectonic setting of the Vanuatu island arc. Prior scientific investigations will be sketched briefly and to the degree to which they are relevant for our further considerations. The consecutive Chapter 3 describes the different data sources used for the calculations. Together, the local earthquake catalogue provided by the IRD (Institut de Recherche pour le D´eveloppement) and the global catalogues constitute a comprehensive data base for the region. The homogenisation of different catalogues required the conversion of magnitudes through maximum likelihood regressions. Chapter 4 gives a brief overview over the methodological concept applied. The implementation of the Cornell methodology involves two key steps: The first step is to construct a seismicity model (Chapter 5) including the definition of source zones and seismicity parameters characterising the level and type of activity in the respective zone. The second step is to determine an appropriate attenuation relation for the earthquake-generated ground motion in dependence of magnitude and distance. Chapter 6 compares several attenuation relations from the recent geophysical literature. We argue that the modeling of attenuation is the weakest link in this analysis and the major source of uncertainty. The new seismic hazard maps are presented and discussed in Chapter 7. The map that we consider to be the most relevant is also shown on the inner title page of this report. Our findings indicate that the seismic hazard in Vanuatu has been underestimated by prior assessments such as the Global Seismic Hazard Assessment Programme GSHAP (cf. Fig. 1.1).

Description: This manual outlines the characteristics and structure of the software and describes how to use the software. The principles and new features are outlined systematically and referred partly to existing references. Numerical examples of multi-functions and internal tests as well as external comparisons are given.

Description: We review the historical, geological, tide-gauge, GPS and gravimetric evidence advanced in favour of or against continuing land uplift around Hudson Bay, Canada. After this, we reanalyse the tide-gauge and GPS data for Churchill using longer time series than those available to previous investigators. The dependence of the mean rate of relative sea-level change obtained on the length and mid-epoch of the observation interval considered is investigated by means of the newly developed linear-trend analysis diagram. For studying the shorter-period variability of the tide-gauge record, the continuous-wavelet transform is used. The mean rate of land uplift obtained from GPS is based on a new analysis using IGS solutions of GFZ. Furthermore, sea-level indicators from the Churchill region representing the relative sea-level history during the past 8000 a are included. Finally, the four types of observable are jointly inverted in terms of mantle viscosity. The optimum values are 3×10^20 Pa s and 1.6 × 10^22 Pa s for the upper- and lower-mantle viscosities, respectively.

Description: Ziel dieser Arbeit ist die Quantifizierung von Modalbeständen magmatischer Gesteine anhand ihrer Infrarot-Spektren, basierend auf einer spektralen Einzelmineralanalyse. Dazu wurde eine neue, modellbasierte, spektrale Entmischungsmethode entwickelt. Diese Methode basiert auf reflexionsspektroskopischen Messungen im thermalen Infrarot von 8 - 14 μm, da in diesem Wellenlängenbereich silikatische Minerale und damit auch magmatische Gesteine ihre stärksten Spektralmerkmale (Reststrahlenbanden) aufweisen. Als Grundlage dienten Gesteinsproben des präkambrischen Gesteinskomplex Mt. Timna in Südisrael, der sich aus verschiedenen granitoiden Gesteinen und einer ultrabasischen Gesteinseinheit zusammensetzt. Die hier vorgestellte Arbeit entstand im Zusammenhang mit vorbereitenden Untersuchungen zur Entwicklung neuer Analysemethoden für einen neuen hyperspektralen Thermalsensors (ARES), der ab 2005 vom GFZ und dem DLR operationell betrieben werden soll.

Description: Der glazio-isostatische Ausgleich in Island als Folge des Abschmelzens der größten europäischen Eiskappe, dem Vatnajökull, verursacht zeitliche Änderungen der Schwere und Landhebung. Nach Auswertung der Schweredaten zeigt sich ein charakteristisches Verhalten. Die Schwereänderungsrate beträgt ca. -4 mikroGal/a am Eisrand (50 km Entfernung vom Eiszentrum)und ca. 1 mikroGal/a in Höfn (75 km Entfernung vom Eiszentrum). In größeren Entfernungen vom Eiszentrum (150 bis 250 km) werden die Raten kleiner als 1 mikroGal/a und nähern sich schließlich Null. Vorwärtsmodellierung liefert eine Lithosphärenmächtigkeit von 10 bis 15 km. Die Asthenosphärenviskosität ist 3 x 1017 bis 1 x 1018 Pa s. Diese Werte bestätigen frühere Resultate aus GPS-, seismischen und theoretischen Untersuchungen. Eine deutlich bessere Anpassung an die Meßdaten ergibt sich für erhöhte Asthenosphäremächtigkeit (165 bis 170km). Vermutlich reflektiert dies die spezielle Lage Islands oberhalb eines Plumes.

Description: Die vorliegende Untersuchung befaßt sich mit dem Einfluß des durch die letzte pleistozänen Enteisung hervorgerufenen glazial-isostatischen Ausgleichs auf die rezente Meeresspiegeländerung. Diese Änderung kann sowohl durch Satellitenaltimetrie als auch durch Pegelmessungen bestimmt werden.

Description: This report is also published as Scientific Report No. 04-9 of the Danish Meteorological Institute.

Description: Die Arbeit untersucht die Möglichkeiten einer Anwendung der Aerogravimetrie bei der Schwerefeldberechnung. Aus fluggestützten Messungen werden Schwerestörungen berechnet, die der Bestimmung regionaler Geoidlösungen dienen. Zunächst wird das Messgerät und seine Funktionsweise erläutert. Anschließend werden drei Verfahren zur Geoidberechnung verglichen, die sich unterschiedlicher Konzepte bedienen: ein Integralverfahren mit abgewandeltem Stokes-Kern, die schwerpunktmäßig behandelte Methode der Multipole sowie das Kollokationsverfahren. Im Gegensatz zum Intergralverfahren arbeiten die Verfahren der Multipole sowie das der Kollokation ohne eine Feldfortsetzung nach unten. Im praktischen Teil der Arbeit werden die Verfahren auf den CHICAGO-Datensatz angewendet, der im Herbst 2002 in Südchile gemessen wurde. Die Genauigkeit sowohl der Messwerte als auch die der Geoidlösungen wird durch einen Vergleich mit unabhängigen Daten untersucht. Es stellt sich heraus, dass alle Verfahren im Rahmen der Genauigkeit zu akzeptablen Lösungen führen. Außerdem wird festgestellt, dass für niedrige Flughöhen der Einfluss der Feldfortsetzung vernachlässigt werden kann.

Description: In this thesis the subduction zone of the Central Andes is studied. The Andes have formed in a complex interplay of subduction related and tectonic processes. The Central Andes with the associated Altiplano-Puna high plateau constitute the second largest continental land-mass on earth, rivaled only by the Tibetan highland. Whereas in the case of the Himalayas , where two buoyant continental plates collide, crustal thickening and uplift is quite intuitive, processes leading to formation of a plateau above a subduction zone are puzzling.

Description: This thesis focuses on the seismic structure of the lithosphere and upper mantle beneath the western Eger Rift area with the aim of investigating deep-lying possible causes of the phenomena observed at surface. For the investigation, data of the international passive seismic experiment BOHEMA carried out in 2002/2003 was used. The BOHEMA network consisted of 61 permanent and 84 temporary stations and was centred on the western Eger Rift. The resulting large data set allowed a high resolution P and S receiver function study using P-to-S and S-to-P converted waves, respectively, to map seismic discontinuities in the lithosphere and upper mantle. Data from an earlier passive seismic experiment was additionally used to complement the BOHEMA data set. The results of the analysis are described in this thesis ‘from top to bottom’. [...] Furthermore, the first map of average crustal vp/vs ratios is presented for the investigated area.

Description: As observed on the Earth's surface, the magnetic field can be separated into three components: The "Main Field", the "Crustal Field" and the "External Magnetic Field". This work concentrates on the magnetospheric current systems, in order to correct the effect of large-scale magnetospheric current systems. Their exact knowledge is vital to improve the main field and secular variation models. Spherical harmonic analysis (SHA) is commonly used to describe the magnetic field. In SHA it is possible to distinguish between internal and external contributions to the Earth's magnetic field. The spherical harmonic coefficients describe dipolar, quadrupolar and higher parts in spherical coordinates. Here, CHAMP (CHAllenging Minisatellite Payload) measurements are used. Due to the inclination CHAMP is changing the orbit in local time. From time to time CHAMP is flying in resonance with the Earth's rotation, i.e. the satellite is flying over the same ground track after a couple of days. To model changes during a period of a few days these so called "repeat tracks" are very helpful for an improved main field/external field model. On the Earth's surface the magnetic effect of magnetospheric currents is often characterised by the DST-indix. In this study, it is explained how a possible constitution of the external sources of the geomagnetic field can look like and how the effect of these magnetospheric currents can be corrected in main field modelling.

Description: The paper consists of two main elements: (1) the creation of a harmonized seismicity data file for the eastern Mediterranean area and the generation of a classical timeindependent PSHA, and (2) the extension of the earthquake model of the timeindependent approach to a newly developed time‐dependent PSHA and the comparison with the results of (1).

Description: Understanding the climate system and the natural processes that lead to its changes is fundamental when trying to evaluate and assess the human influence on climate variability. Human activities characterised most of the Holocene time period, so that palaeoclimate sequences of the last 8,000 years recorded both climate change and human impact. In order to study natural climate variability, we have to investigate past interglacial climate records, when human impact was none. Amongst many palaeoclimate archives, lacustrine varved sequences are invaluable records that allow high resolution palaeoclimate reconstruction. The interglacial lake deposits of Piànico (Southern Alps) consist of ca 15,500 biochemically precipitated calcite varves. The goal of my research is the sedimentological, geochemical and isotopical study at seasonal/decadal resolution of climate variability as recorded in this sequence. The chronology obtained from varve counting constitutes a floating chronology of an interglacial period; the recovery of two tephra layers allowed to fix the floating chronology to the interglacial centred at 400 ka BP, thus corresponding to MIS 11. I studied the upper 5,900 varves at seasonal resolution, using a multi proxy approach. The thickness of summer layers is the proxy for productivity and spring-summer temperature, whereas detrital layers indicate extreme precipitation events; δ18O has been used as a proxy for temperature and/or air masses circulation. I developed a new sampling technique for isotope analyses, in order to ensure the sampling of endogenic calcite, avoiding detrital contamination; this method also allowed me to quantify the effect of Triassic dolomite in bulk carbonate samples. The 15.5 ka of interglacial conditions in Piànico are characterised by short-term climate change. At least four rapid climatic oscillations and a climatic deterioration at the very end of the 15,500 years are recorded. The main climatic oscillation is a 1000 years long cold period that took place after ca 10,000 years of interglacial conditions. This type of climate oscillation has not been recorded in the Holocene yet. This implies that, so far, the Holocene has not experienced all the possible range of interglacial climate changes.

Description: Diese Dokumentation beschäftigt sich mit der Baugeschichte des Meridianhauses im Ensemble des Observatoriums für Winkelmessungen des Magnetisch-Geodätischen Instituts auf dem Telegrafenberg bei Potsdam.

Description: In this report, we will present the complete derivation of analytical expressions of the EM coupling torque in dependence on the parameters of the fields contributing to it. For this, we choose a special set of spherically harmonic (SH) base functions and present all major steps of the derivation. Our report will be (i) closer to a lecture note than to a scientific paper and should give all readers the possibility to follow the derivations with the related details in the appendix, and can be (ii) used as a formulary for scientists working on this special field of investigation.

Description: In der vorliegenden Arbeit werden der Einfluss seismischer Anisotropie auf wahre oder scheinbar auftretende tensile Quellanteile untersucht und Erdbebenmechanismen unter Berücksichtigung seismischer Anisotropie bestimmt. Es wird gezeigt, dass der Momententensor und die Abstrahlmuster eines Scherbruches im anisotropen Medium denen eines tensilen Bruches im isotropen Medium ähneln können. Umgekehrt treten Ähnlichkeiten tensiler Beben in anisotropen Gesteinen mit Scherbrüchen in isotropen Medien auf. Damit existieren Mehrdeutigkeiten beobachteter tensiler Quellanteile. Die Effekte von Anisotropie hängen von der Orientierung des Bruches und vom Grad der Anisotropie ab. Außerdem beeinflusst Anisotropie das Moment eines Bebens. [...] Mit dieser Arbeit werden erstmals zeitliche und räumliche Veränderungen tensiler Quellanteile und Spannungszustände im Vogtland für Erdbeben im Jahr 2000 beob- achtet. Diese haben auch dann Bestand, wenn seismische Anisotropie berücksichtigt wird. Sie können durch Fluide erklärt werden, die in die Bruchflächen eindringen.

Description: Das Veranstaltungsthema „Innovation und Zukunft der Steine- und Erden-Industrie in Mitteleuropa“ wurde gewählt, um die seit 30 Jahren verpasste Gelegenheit ins Bewusstsein zu rufen, dass eine moderne Industrie heimische Rohstoffe benötigt. Wie sich aus den Einzelbeiträgen und den Tabellen entnehmen lässt, ist die Bundesrepublik Deutschland hinsichtlich der Steine und Erden ein rohstoffreiches Land und ein wesentlicher Wirtschaftsfaktor. Dieses Bewusstsein scheint bei der überbordenden ‚Ökologie’-diskussion erst seit kurzer Zeit in den Fokus zu geraten, wurde doch bei allen Diskussionen der Naturschutzgesetzgebung etc. fast völlig vergessen, dass Rohstoffabbau nur möglich ist, wenn Vorrang- oder Schutzzonen mindestens für die nächsten 50 Jahre ausgewiesen werden, wobei das eine Daueraufgabe in der Zeit ist. Diese Aufgabe ist eigentlich eine Hoheitsaufgabe und setzt auch die geologisch / bodenkundliche Basiskartierung der Bundesrepublik Deutschland auf neuesten Stand flächendeckend voraus, um flexibel mit neuen Konzepten auf neueste industrielle Herausforderungen antworten zu können. NEGENDANK (2005) hat einige statistische Daten zusammengetragen, aus denen die Bedeutung im Überblick hervorgeht (Tab. S. 3). Die hier vorgelegten Beiträge erlauben einen vertiefenden Einblick in die Situation der Steine- und Erdenindustrie, ihres Innovationspotentials sowie ihrer Zukunft.

Description: In diesem Bericht werden die Ergebnisse der neuen Generation probabilistischer seismischer Gefährdungseinschätzungen (PSHA) in der Version von 2007 vorgestellt. Die Parametrisierung der Berechnungsergebnisse erfolgt in Form spektraler Antwort- Beschleunigungen und der Spitzenbodenbeschleunigungen (PGA). Bezüglich ersterer stellen sie eine Neuheit für die Bundesrepublik Deutschland dar, während letztere die PGA-Karten von 1997 ersetzen.

Description: Die vorliegende Arbeit beschäftigt sich mit der kombinierten strukturgeologischen und magnetotellurischen Untersuchung eines Segmentes der ’West Fault’-Störung in den nordchilenischen Anden. Die West Fault ist ein Abschnitt des über 2000 km langen Präkordilleren-Störungssystem, welches im Zusammenhang mit der Subduktion vor der südamerikanischenWestküste entstanden ist. Die Aktivität dieses Störungssystems reichte vom Eozän bis in das Quartär. Der Verlauf der West Fault ist im Untersuchungsgebiet (22° 04’ S, 68° 53’W) an der Oberfläche klar definiert und weist über viele zehner Kilometer eine konstante Streichrichtung auf. Die Aufschlussbedingungen und die Morphologie des Arbeitsgebietes sind ideal für kombinierte Untersuchungen der störungsbezogenen Deformation und der elektrischen Leitfähigkeit des Untergrundes mit Hilfe magnetotellurischer Experimente (MT) und der erdmagnetischen Tiefensondierung (GDS). Ziel der Untersuchungen war es, eine mögliche Korrelation der beiden Meßmethoden herauszuarbeiten, und die interne Störungsarchitektur der West Fault umfassend zu beschreiben.

Description: For the motivation behind our investigations, we refer to the introduction of the first part of our report, Hagedoorn & Geiner-Mai (2008). In this part, we will (i) give an analytical description of the topographic surface of the core-mantle boundary (CMB) and derive an approximation for its normal unit vector containing information about the CMB topography, and (ii) derive an expression for the topographic torque as a function of the topographic height, h, and the velocity field, u. For this, we will check the assumptions made when applying the geostrophic approximation to the upper core-surface region. Finally, we will derive analytical expressions for the torque components depending upon the spherical harmonic (SH) coefficients of h and u in a cartesian geocentric coordinate system.

Description: This volume contains extended abstracts from talks and posters presented at the sixth TRACE (Tree Rings in Archaeology, Climatology and Ecology) conference, held in Riga (Latvia) May 3rd – 6th, 2007.

Description: Based on the physical processes governing the motion and dynamics of poly-thermal ice sheets, we distinguish two regions; the cold region, where the ice temperature is below the melting point, and the temperate region, where the ice temperature is exactly equal to the melting point, leading to the presence of a water fraction. This work focuses on the analysis and description of the temperate zone on the basis of rational thermo-dynamics of reacting mixtures. The balance laws for the ice-water mixture, that is the mass balance, balance of linear and angular momenta, energy and entropy, are discussed. A physical model for a polythermal ice sheet is then established, including appropriate boundary and transition conditions. The resulting formulation is convenient for numerical implementation. Numerical examples are carried out for a stationary 2-D case and the results of the present and traditional formulations are compared.

Description: Bivergent wedges result from the interaction between deformation, flexure and surface processes. Based on 2D sandbox simulations in conjunction with PIV, this study investigates the influence of these processes on the spatio-temporal evolution of strain-partitioning within, and the associated surface uplift of, bivergent wedges. To facilitate interpretation and to successfully communicate results, two new display types, i.e., the surface uplift and the evolution of deformation map are introduced.

Description: In Südostalaska wird eine relative Meeresspiegelabsenkung von bis zu 4 cm/ a beobachtet. Da dieses Gebiet während der letzten Kaltperiode durch das Kordillerische Eisschild bedeckt war und noch heute von Vergletscherung geprägt ist, liegt die Vermutung nahe, daß die Meeresspiegeländerungen zumindest teilweise durch isostatische Ausgleichsvorgänge hervorgerufen werden. Um diese Hypothese zu prüfen, werden für dieses Gebiet eislastinduzierte Vertikalbewegungen und Geoidänderungen mit Hilfe viskoelastischer Erdmodelle berechnet. Insbesondere werden sechs siebenschichtige Erdmodelle verwendet, die unterschiedliche Viskostitätsprofile berücksichtigen und die Bandbreite der plausiblen Lithosphärenmächtigkeiten abdecken. Das globale Lastmodell ICE-3G wird erweitert und das regionale Lastmodell AL-1 entwickelt, welches die rezente Vergletscherung Südostalaskas berücksichtigt. Weiterhin werden die Ozeane als Last einbezogen. Ein Vergleich der berechneten mit den beobachteten Meeresspiegeländerungen zeigt, daß die Beobachtungen nur zu einen geringen Anteil von wenigen Millimetern pro Jahr durch Isostasie erklärt werden können.

Description: This work describes the results of seismological field campaigns and experiments using combined seismic networks of varying geometries such as a combined seismic downhole and surface network or a combined temporary local and permanent regional network. The networks were deployed in different tectonic environments, i.e. in a stable intraplate surrounding, at a plate boundary along a major transform fault zone and in forearc and backarc settings of a subduction zone to record different types of seismicity (induced earthquakes, aftershocks, subduction-related seismicity). Recording periods are typically several months. The basic ideas behind all the different experiments and studies presented here can be described as follows: In a first step, a state of the art seismic network is designed and deployed in a selected area to record local (micro)seismic activity at low magnitude detection threshold. The acquired data base is then evaluated using standard processing techniques to generate a proper hypocenter catalog for the area of investigation during the observational period. This period might be extended (at higher magnitude detection threshold) through re-evaluating and calibrating earlier hypocenter catalogs gained from records of regional permanent networks. This new catalog for the selected region then forms the base for further evaluation using different approaches one of which is the determination of fault plane solutions in order to determine the local stress field orientation and relate it to the WSM data or information on regional displacement fields determined from GPS recordings.

Description: In this study two aspects of the geomagnetic field have been investigated. The first part focuses on perturbations of the external field, as seen by the CHAMP satellite and predicted by the Thermosphere-Ionosphere Electrodynamic General Circulation Model, for the purpose of helping to separate out ionospheric sources from the ambient geomagnetic field using a physics based approach. Part two looks at variations of the internal field through an examination of the South Atlantic Anomaly.

Description: This thesis presents investigations on sediments from two African lakes which have been recording changes in their surrounding environmental and climate conditions since more than 200,000 years. Focus of this work is the time of the last Glacial and the Holocene (the last ~100,000 years before present [in the following 100 kyr BP]). One important precondition for this kind of research is a good understanding of the present ecosystems in and around the lakes and of the sediment formation under modern climate conditions. Both studies therefore include investigations on the modern environment (including organisms, soils, rocks, lake water and sediments).

Description: The aim of this dissertation is to quantify scaling relations of strain accumulation in nature on various temporal and spatial scales, in order to characterize the underlying deformation mechanisms [...] Apart from the introduction (Chapter 1), the dissertation is divided into eight further chapters: a review of the common deformation frameworks, scaling relations and their dependence on parameter changes (Chapter 2); a description of the applied methods (Chapter 3); a description of the tectonic setting of the Central Andean plateau (Chapter 4); three scientifi c manuscripts for publication in international peer-reviewed journals (Chapter 5, 6, 7); additional analogue data (Chapter 8); and conclusions with outlook on future research (Chapter 9). The appendix includes all references used in any of the chapters, the deformation database used in Chapter 5, more geostatistical data, data for the sensitivity analysis, a short documentation on all performed granular experiments with set-up sketches, material properties of vise experiments, acknowledgments, and a CV.

Description: The Eifel is the youngest volcanic area of Central Europe. The last eruption occurred approximately 11000 years ago. Little is known about the deep origin and the mechanism responsible for the Eifel volcanic activity. Earthquake activity indicates that the Eifel is one of the most geodynamically active areas of Central Europe. In this work the receiver function method is used to investigate the upper mantle structure beneath the Eifel. Data from 96 teleseismic events (mb 〉 5.2) that were recorded by both permanent stations and a temporary network of 33 broadband and 129 short period stations had been analyzed. The temporary network was operating from November 1997 till June 1998 and covered an area of approximately 400x250 km^2 centered on the Eifel volcanic fields. The receiver function analysis reveals a clear image of the Moho and the mantle discontinuities at 410 km and 660 km depth. Average Moho depth is approximately 30 km and it shows little variation over the extent of the network. The observed variations of converted waveforms are possibly caused by lateral variations in crustal structure, which could not resolved by it receiver functions}. Inversions of data and migrated it receiver functions} from stations of the central Eifel array suggest that a low velocity zone is present at about 60 to 90 km depth in the western Eifel region. There are also indications for a high velocity zone around 200 km depth, perhaps caused by dehydration of the rising plume material. The results suggest that P-to-S conversions from the 410-km discontinuity arrive later than in the IASP91 reference model. The migrated data show a depression of the 410 km discontinuity of about 20 km, which correspond to an increase of temperature of about 140° Celsius. The 660 km discontinuity seems to be unaffected. This indicates that no mantel material rises up from directly below the 660 km discontinuity in the Eifel region or the Eifel-Plume has its origin within the transition zone.

Description: The objective of this study is to calculate the RSL height at the location of the Berkner Island ice core during the last glacial cycle using a viscoelastic earth model and several glacial histories. Earlier glacial cycles are not considered, the basic assumption being that the sediments were deposited during the last glacial cycle. However, to some extent the results can be extrapolated further back into the past. The results impose a constraint on the time of deposition of the sediments. Conversely, if the time of deposition is determined, e. g. by luminescence dating, this study provides a constraint on the glacial history of the Ronne Ice Shelf.

Description: The report describes the main results of investigations performed in 2001 year in framework of a research contract between GeoForschungsZentrum Potsdam (GFZ) and the Institute of Radio Engineering and Electronics of the Russian Academy of Sciences, Moscow (IRE).

Description: Der Scientific Technical Report (STR) 03/08 ist die teilweise überarbeitete Diplomarbeit des Autors, welche im November 2002 am Lehrstuhl für Astronomie des Instituts für Planetare Geodäsie der Fakultät Forst-, Geo- und Hydrowissenschaften an der Technischen Universität Dresden eingereicht wurde.

Description: In the present thesis, interactions of kimberlites and lamproites as well as their constituent minerals with fluids are discussed based on noble gas compositions. The samples originate from the eastern Baltic Shield, more specifically from the Kola craton (Poria Guba and Kandalaksha) and the Karelia craton (Kostamuksha). Gas was extracted by stepwise heating and crushing from 23 whole rock samples and 15 mineral separates. These two techniques allow differential extraction of gas from fluid inclusions (crushing technique) and from the bulk sample (stepwise heating).

Description: After a gap of nearly two decades since the Magsat mission in 1980, the dedicated low-orbit potential field mission CHAMP is now in the third of its seven year mission. Already, the new magnetic total intensity and vector data have yielded maps of the global crustal field of unprecedented accuracy and resolution. Here, we assess the value of these maps to infer deep crustal structure of regions overlain by younger cover. A GIS based modelling technique has been developed to model the various geological units of the continents starting from the geological map of the world. Depending upon the known rock types of the region, they are assigned a standard susceptibility value and using the global seismic crustal structure, a vertically integrated susceptibility (VIS) model is computed at each point of the region. Starting with this initial VIS model, the vertical field anomaly is computed at a satellite altitude of 400 km and compared with the corresponding CHAMP vertical field anomaly map. The first comparison is carried out against a model using the lateral extent of a cratonic region as given by published tectonic maps. In the subsequent modelling step, depending upon the extent of the observed anomaly pattern of that region, the surface geology is extended beneath the sediments until the recomputed map fits the observed magnetic anomaly map. Here, we focus on modelling results for the selected few provinces of the world where the initial model does not agree with the observed anomaly map. Similar modelling of CHAMP satellite magnetic anomalies can constrain the subsurface structure hidden by Phanerozoic cover in many parts of the world.

Description: Following work is embedded in the multidisciplinary study DESERT (DEad SEa Rift Transect) that has been carried out in the Middle East since the beginning of the year 2000. It focuses on the structure of the southern Dead Sea Transform (DST), the transform plate boundary between Africa (Sinai) and the Arabian microplate. In this work a short description of the seismic reflection method and the various processing steps is followed by a geological interpretation of the seismic data, taking into account relevant information from other studies.

Description: Die südlichen Anden sind Teil des aktiven Kontinentalrandes von Südamerika, der durch eine Kombination subduktionsgebundener Prozesse gebildet wurde. Die andine Gebirgskette erstreckt sich über den gesamten südamerikanischen Kontinent, variiert jedoch merklich in Höhe und Krustenmächtigkeit. Während die Zentralen Anden, vor allem auch die tieferen Strukturen bis in den oberen Mantel, vergleichsweise gut erforscht sind , ist über den geophysikalischen Aufbau der südlichen Anden bisher relativ wenig bekannt. Aus diesem Grund wurde das seismische Experiment ISSA2000 in den südlichen Anden durchgeführt. In dieser Arbeit wurde mithilfe der Methode der lokalen Erdbebentomographie ein 3-D Modell der seismischen Geschwindigkeitstruktur erstellt. Die gleichzeitig durchgeführte Lokalisierung der registrierten Erdbeben, ergibt darüberhinaus ein detailliertes Bild der Verteilung der Seismizität im Untersuchungsgebiet. Im Rahmen des ISSA2000-Experimentes wurde ein seismologisches Netzwerk mit 62 Seismographen betrieben, das die Subduktionszone von der Küste bis in den backarc zwischen 36° und 40°S überdeckt. Die Hypozentren der 440 lokalen Erdbeben zeigen eine ~30° geneigte Wadati-Benioff-Zone mit kontinuierlicher Seismizität bis in 120km Tiefe, die vereinzelt bis in 200km Tiefe zu beobachten ist. Sowohl die generell geringe Seismizität im Untersuchungsgebiet als auch die geringe Tiefenerstreckung der Wadati-Benioff-Zone u.a. im Vergleich zu den Zentralen Anden sowie die Konzentration der mitteltiefen Erdbeben in 60km Tiefe, spiegeln wahrscheinlich den Einfluß des jungen Alters und des damit verbundenen hohen thermischen Zustandes der Nazca-Platte auf das Subduktionsregime wider. Das tomographische Vp Modell zeigt zum ersten Mal die Geschwindigkeitsstruktur der südlichen Anden bis in eine Tiefe von 100km. Die Nazca-Platte ist durch die Lage der Erdbeben definiert und durch hohe Vp Geschwindigkeiten gekennzeichnet . Die durchschnittlichen Geschwindigkeiten in der kontinentalen Kruste sind im gesamten Vp Modell relativ hoch . Die tieferliegende Struktur kann in drei Gebiete unterteilt werden. Erniedrigte Vp Geschwindigkeiten in 30-50km Tiefe unterhalb der Küstenkordillere und oberhalb der abtauchenden Platte deuten eine mögliche Hydratisierung und Serpentinisierung des kontinentalen Mantelkeils an. Die Konzentration der Erdbeben in 60km Tiefe, die auf Dehydratisierungsprozesse innerhalb der subduzierten ozeanischen Lithosphäre zurückzuführen ist, könnte mit der beobachteten Geschwindigkeitsanomalie verbunden sein. Der Bereich unterhalb des Längstals ist von einer markanten Anomalie erhöhter Vp Geschwindigkeiten geprägt, die das gesamte Untersuchungsgebiet von N nach S durchzieht. Mantelgeschwindigkeiten werden hier ab 40km Tiefe erreicht. Weiter nach Osten nimmt die Krustenmächtigkeit zu und erreicht 50-55km unterhalb der Hauptkordillere und des aktiven vulkanischen Bogens. Geringe Geschwindigkeiten, ein erhöhtes Vp/Vs Verhältnis und die sich durch die Spektralanalyse andeutende Zone erhöhter seismischer Dämpfung könnte auf das Vorhandensein partieller Schmelzen und deren mögliche Anlagerung unterhalb der Kruste hindeuten.

Description: Diese Arbeit beschäftigt sich vor allem mit einem neuen Verfahren zur Abbildung von Leitfähigkeitsstrukturen. Mit der Propagation Number Analysis (PNA), die auf einen mathematischen Formalismus von Reilly [1979] zurück geht und die im Rahmen dieser Arbeit in einen physikalischen Kontext dargestellt wird, ist es möglich, die gesamte Tensor- Information in eine Widerstandsellipse zu transformieren. Sie gibt im übertragenen Sinn die Vorzugsrichtung der Ströme an und liefert somit ein Abbild der Leitfähigkeitsverteilung. Die graphische Präsentation fand bislang für transiente elektromagnetische Messungen Verwendung [Caldwell & Bibby, 1998], um einen wahren Widerstandstensor darzustellen. Die Widerstandsellipsen ergeben aufgrund von Geometrie und Farbkodierung flächenhaft ein Bild, in dem leitfähige Strukturen auch ohne Kenntnisse der MTTheorie erkennbar sind. Die dadurch gewonnenen Informationen lassen sich direkt mit der Geologie vergleichen oder für eine Modellierung nutzen.

Description: The Dead Sea Transform (DST) is a prominent shear zone in the Middle East. It separates the Arabian plate from the Sinai microplate and stretches from the Red Sea rift in the south via the Dead Sea to the Taurus-Zagros collision zone in the north. Formed in the Miocene »17 Ma ago and related to the breakup of the Afro-Arabian continent, the DST accommodates the left-lateral movement between the two plates. The study area is located in the Arava Valley between the Dead Sea and the Red Sea, centered across the Arava Fault (AF), which constitutes the major branch of the transform in this region. A set of seismic experiments comprising controlled sources, linear profiles across the fault, and specifically designed receiver arrays reveals the subsurface structure in the vicinity of the AF and of the fault zone itself down to about 3–4 km depth. A tomographically determined seismic P velocity model shows a pronounced velocity contrast near the fault with lower velocities on the western side than east of it. Additionally, S waves from local earthquakes provide an average P -to-S velocity ratio in the study area, and there are indications for a variations across the fault. High-resolution tomographic velocity sections and seismic reflection profiles confirm the surface trace of the AF, and observed features correlate well with fault-related geological observations. Coincident electrical resistivity sections from magnetotelluric measurements across the AF show a conductive layer west of the fault, resistive regions east of it, and a marked contrast near the trace of the AF, which seems to act as an impermeable barrier for fluid flow. The correlation of seismic velocities and electrical resistivities lead to a characterisation of subsurface lithologies from their physical properties. Whereas the western side of the fault is characterised by a layered structure, the eastern side is rather uniform. The vertical boundary between the western and the eastern units seems to be offset to the east of the AF surface trace. A modelling of fault-zone reflected waves indicates that the boundary between low and high velocities is possibly rather sharp but exhibits a rough surface on the length scale a few hundreds of metres. This gives rise to scattering of seismic waves at this boundary. The imaging (migration) method used is based on array beamforming and coherency analysis of P -to-P scattered seismic phases. Careful assessment of the resolution ensures reliable imaging results. The western low velocities correspond to the young sedimentary fill in the Arava Valley, and the high velocities in the east reflect mainly Precambrian igneous rocks. A 7 km long subvertical scattering zone (reflector) is offset about 1 km east of the AF surface trace and can be imaged from 1 km to about 4 km depth. The reflector marks the boundary between two lithological blocks juxtaposed most probably by displacement along the DST. This interpretation as a lithological boundary is supported by the combined seismic and magnetotelluric analysis. The boundary may be a strand of the AF, which is offset from the current, recently active surface trace. The total slip of the DST may be distributed spatially and in time over these two strands and possibly other faults in the area.

Description: Ein transversales Störungssystem im Nahen Osten, die Dead Sea Transform (DST), trennt die Arabische Platte von der Sinai-Mikroplatte und erstreckt sich von Süden nach Norden vom Extensionsgebiet im Roten Meer über das Tote Meer bis zur Taurus-Zagros Kollisionszone. Die sinistrale DST bildete sich im Miozän vor »17 Ma und steht mit dem Aufbrechen des Afro-Arabischen Kontinents in Verbindung. Das Untersuchungsgebiet liegt im Arava Tal zwischen Totem und Rotem Meer, mittig über der Arava Störung (Arava Fault, AF), die hier den Hauptast der DST bildet. Eine Reihe seismischer Experimente, aufgebaut aus künstlichen Quellen, linearen Profilen über die Störung und entsprechend entworfenen Empfänger-Arrays, zeigt die Untergrundstruktur in der Umgebung der AF und der Verwerfungszone selbst bis in eine Tiefe von 3–4 km. Ein tomographisch bestimmtes Modell der seismischen Geschwindigkeiten von P-Wellen zeigt einen starken Kontrast nahe der AF mit niedrigeren Geschwindigkeiten auf der westlichen Seite als im Osten. Scherwellen lokaler Erdbeben liefern ein mittleres P -zu-S Geschwindigkeitsverhältnis und es gibt Anzeichen für Änderungen über die Störung hinweg. Hoch aufgelöste tomographische Geschwindigkeitsmodelle bestätigen der Verlauf der AF und stimmen gut mit der Oberflächengeologie überein. Modelle des elektrischen Widerstands aus magnetotellurischen Messungen im selben Gebiet zeigen eine leitfähige Schicht westlich der AF, schlecht leitendes Material östlich davon und einen starken Kontrast nahe der AF, die den Fluss von Fluiden von einer Seite zur anderen zu verhindern scheint. Die Korrelation seismischer Geschwindigkeiten und elektrischer Widerstände erlaubt eine Charakterisierung verschiedener Lithologien im Untergrund aus deren physikalischen Eigenschaften. Die westliche Seite lässt sich durch eine geschichtete Struktur beschreiben, wogegen die östliche Seite eher einheitlich erscheint. Die senkrechte Grenze zwischen den westlichen Einheiten und der östlichen scheint gegenüber der Oberflächenausprägung der AF nach Osten verschoben zu sein. Eine Modellierung von seismischen Reflexionen an einer Störung deutet an, dass die Grenze zwischen niedrigen und hohen Geschwindigkeiten eher scharf ist, sich aber durch eine raue Oberfläche auf der Längenskala einiger hundert Meter auszeichnen kann, was die Streuung seismischer Wellen begünstigte. Das verwendete Abbildungsverfahren (Migrationsverfahren) für seismische Streukörper basiert auf Array Beamforming und der Kohärenzanalyse P -zu-P gestreuter seismischer Phasen. Eine sorgfältige Bestimmung der Auflösung sichert zuverlässige Abbildungsergebnisse. Die niedrigen Geschwindigkeiten im Westen entsprechen der jungen sedimentären Füllung im Arava Tal, und die hohen Geschwindigkeiten stehen mit den dortigen präkambrischen Magmatiten in Verbindung. Eine 7 km lange Zone seismischer Streuung (Reflektor) ist gegenüber der an der Oberfläche sichtbaren AF um 1 km nach Osten verschoben und lässt sich im Tiefenbereich von 1 km bis 4 km abbilden. Dieser Reflektor markiert die Grenze zwischen zwei lithologischen Blöcken, die vermutlich wegen des horizontalen Versatzes entlang der DST nebeneinander zu liegen kamen. Diese Interpretation als lithologische Grenze wird durch die gemeinsame Auswertung der seismischen und magnetotellurischen Modelle gestützt. Die Grenze ist möglicherweise ein Ast der AF, der versetzt gegenüber des heutigen, aktiven Asts verläuft. Der Gesamtversatz der DST könnte räumlich und zeitlich auf diese beiden Äste und möglicherweise auch auf andere Störungen in dem Gebiet verteilt sein.

Description: This thesis work describes a new experimental method for the determination of Mode II (shear) fracture toughness, KIIC, of rock and compares the outcome to results from Mode I (tensile) fracture toughness, KIC, testing using the International Society of Rock Mechanics (ISRM) Chevron-Bend (CB-) method. The fracture toughness describes the resistance of rock to fracturing. This parameter is therefore important when estimating the failure of rock and rock structures using rock fracture mechanics principles.

Description: Der vorliegende Report fasst die wissenschaftlichen und technischen Arbeiten zur Steigerung der Produktivität von Thermalwasser in der Geothermie-Forschungsbohrung Groß Schönebeck 3/90 zusammen, die von 2002 bis 2004 durchgeführt wurden. Das Ziel des Projektes ist die Erschließung von heißen Wässern in tiefen Speichergesteinen, die sich zur Erzeugung von elektrischem Strom eignen. Dies erfordert die Bereitstellung einer kontinuierlichen Förderung heißer Tiefenwässer mit Temperaturen 〉 150 °C und Fließraten 〉 50 m³/h. In Tiefen mit Mindesttemperaturen um 150 °C ist die natürliche Permeabilität (Durchlässigkeit) der Gesteine jedoch nicht ausreichend. Die Gesteine müssen stimuliert werden, d. h. zu vorhandenen Rissen werden zusätzliche künstlich erzeugt, damit das Wasser ungehindert zirkulieren kann. Bereits vorliegende Erkenntnisse zur Erschließung und Charakterisierung der in weiten Regionen des Norddeutschen Sedimentbeckens in Tiefen von etwa 4000 bis 5000 Metern verbreiteten Speichertypen basieren größtenteils auf Erfahrungen der Erdöl- und Erdgasindustrie. Für die geothermische Nutzung sind diese jedoch nur eingeschränkt anwendbar, da bei der Erschließung von Kohlenwasserstoffen schon kleine Fließraten genügen. Daher liegt der Schlüssel zum Durchbruch der Geothermie in der Entwicklung effektiver Stimulationstechniken zur gezielten Produktivitätssteigerung geothermischer Reservoire. Die Geothermiebohrung Groß Schönebeck schließt geothermisch relevante Horizonte des Norddeutschen Beckens zwischen 3900 m und 4300 m in einem Temperaturniveau von etwa 150 °C auf. Diese Bohrung bietet derzeit die einzigartige Möglichkeit, die geothermische Nutzbarkeit unterschiedlicher Gesteinsformationen des Rotliegenden vertiefend zu untersuchen: die Vulkanite an der Basis und den darüber liegenden Sandstein. Experimente zur Erhöhung der Zuflussrate von heißen Wässern aus Sandsteinformationen durch hydraulische Stimulation konnten bereits erfolgreich durchgeführt werden (siehe Berichte zu den Projekten BEO 0327063 und ZIP 0327063C). Die erzielten Fließraten reichten jedoch für eine wirtschaftliche Elektrizitätserzeugung noch nicht aus. Daher wurden die Sandsteinformationen gemeinsam mit darunter liegenden Vulkaniten durch neu konzipierte Stimulationsverfahren erschlossen. Die angewendeten Methoden gleichen den vorhergehenden Projekten, wo durch hydraulisches Pumpen zusätzliche Risse im Gestein geschaffen werden. Bei entsprechender Produktionssteigerung von heißen Wässern aus dem Untergrund ist als anschließender Schritt eine zweite Bohrung geplant, mit der ein Förder- und Versenkkreislauf hergestellt werden kann. Ein geothermisches Kraftwerk vervollständigt die Installation. Da im Sedimentbecken von den Niederlanden über Norddeutschland bis nach Polen ähnliche geologische Verhältnisse vorliegen, haben die Ergebnisse aus der Bohrung Groß Schönebeck Pioniercharakter. Der Lern- und Anwendungseffekt aus den Experimenten kann unter diesem Aspekt als besonders beachtenswert eingestuft werden.

Description: The main objective of this thesis is an investigation and description of the secular variation of the Earth's magnetic field between 1980 and 2000. In particular, in the first part of this study the phenomenon of geomagnetic jerks are investigated by means of a deterministic model, which basically gives a description of the secular variation as a parameterization of typical periodicities of the external field. I argue that the conclusion drawn from this approach is not valid for explaining jerks as caused by external events and not valid to describe the global secular variation. In the second part a time--dependent model of the secular variation between 1980 and 2000 is developed. The endpoints of the time interval were chosen, because of the availability of high quality field models from satellite data for these epochs. The Gauss coefficients are expanded in time as function of cubic B--splines. This model is forced to fit field models from high quality vector measurements from MAGSAT in 1980 and OERSTED in 2000. The methodology is new. The model is a valuable extension of the hitherto existing time--dependent description of the secular variation, the GUFM which was valid until 1990. Unlike GUFM the model is based on observatory monthly means, and the knot spacing of the cubic B--Splines tighter than GUFM. Therefore it reveals a short term secular variation on subdecadal time scale, which was not as yet resolved. The model is also valuable to test the frozen flux hypothesis and to link some of the morphology of the radial field at the core--mantle boundary to the geodynamo. The third part of this thesis deals with the inversion of the time--dependent field and secular variation model for different kinds of core surface flow. These flows allow prediction of the decadal change of the length of the day, an observable which is independent to geomagnetic data. The prediction of some of the flows have the right tendency, but differ in slope from the observed change of the length of the day.

Description: For identification of the impact of salt-free and soured fluids injected for hydraulic stimulation on the about 4,000 m deep Rotliegend sandstones, cross-flow tests were carried out in combination with petrographic and fluid-chemical investigations. As a consequence of the swelling and the potential mobilisation of the clay minerals, a reduction of the permeability was expected. However, the test did not produce any significant change of the permeability for the cross-flow of differently conditioned waters under modified p/T conditions. But there could be proven the mobilisation of heavy metals and the solution of carbonate cement. As these cement minerals form a small fraction only in the total rock and due to their uneven distribution, no damage of the aquifer has to be expected. A local transport of finest particles could be observed which is probably connected with the carbonate solution. In case of suddenly increasing pore pressures, there is a risk of particle discharge, so that damaging of the pore reservoir cannot be excluded due to this small-scale transport of particles.

Description: The work contained in this thesis considers deformations of the Earth, which are produced by the loads of the last ice-age glacial sheets. The forces the Earth sets against the surface loads are the buoyancy force of the Earth's mantle and the opposing force by the elastic flexure of the lithosphere. Because the time scale of the ice-age of some 100,000 years is short with respect to geological time scales, the viscoelastic behaviour of the Earth has to be considered. Viscoelasticity results in a retarded response of the Earth, which is observed as postglacial uplift in previously glaciated regions, 8,000 years after deglaciation. To model the buoyancy of the Earth's mantle, often a viscous incompressible fluid of homogeneous density is assumed. More recent studies consider also compressibility of the mantle material, but keep the homogeneous density. This results in an inconsistent reference state, because the self compression due to hydrostatic pressure is neglected. These models are discussed here, and the problems are shown, which arise from the description of the field equations for a viscoelastic compressible gravitating continuum in a half-space geometry. The opposing force by the elastic flexure of the lithosphere is determined by the flexural rigidity of the lithospheric plate. If we consider viscoelastic layers in the lithosphere, the flexural rigidity is reduced. Therefore, the overall thickness of a viscoelastic layered lithosphere is much larger than its effective elastic thickness deduced from assuming one elastic plate. Consequently the effective elastic thickness looses its merit for assessing the lithosphere thickness. We show, how strong effective elastic thickness and lithosphere thickness may differ, in which way the viscoelastic structure of the Earth influences this difference for glacial loads and which consequences arise for the lithospheric stress state.

Description: The main objective of this study is the quantification and qualification of strain over a broad scale range, including its distribution, magnitude, and accumulation history during basin evolution. These objectives are important contributions to the questions of stress transfer and deformation processes in the Southern Permian Basin.

Description: [...] According to the results of this thesis the following mechanism is suggested to cause the cusp-related density anomaly: The energy input by the solar wind, as characterised by the merging electric field, provides the power for Joule heating of preferably neutral molecules. Soft particle precipitation in the cusp simultaneously enhances the altitude of maximal Pedersen conductivity, thus lifting up the heated layer in the cusp. The cusp-related density anomaly is then caused by local composition changes in the upper atmosphere due to the differential expansion of heavier particles. The density enhancement is more intensive during phases of high solar activity, i.e. a larger background density favours the formation of large anomalies. The atmospheric fountain in the cusp region affects the upper atmosphere globally. The harmonic exitation of the fountain in 2005 caused a global density variation of the thermosphere.

Description: Der vorliegende Bericht fasst die Ergebnisse der in den Jahren 2000 und 2001 durchgeführten Arbeiten zur Aufwältigung, zum primären Test- und Messprogramm sowie zum Monitoring in der Geothermiebohrung Groß Schönebeck 3/90 zusammen. Mit Mitteln aus der Grundfinanzierung des GeoForschungsZentrums Potsdam wurde die Bohrung aufgewältigt und bis in eine Endteufe von 4294 m vertieft. Sie erschließt geothermisch interessante Horizonte des Norddeutschen Beckens in Tiefen zwischen ca. 3900 m und 4300 m bei einem Temperaturniveau von ca. 150°C. Dabei gewonnene Ergebnisse lassen sich auf ähnliche geologische Randbedingungen im Norddeutschen Becken übertragen. Dieses Sedimentbecken zieht sich von den Niederlanden über Norddeutschland bis nach Polen hin.

Description: The dynamic oblateness of the Earth, in terms of the J2 or C20 coefficient of the Earth´s geo-potential has been derived by analysis of LAGEOS Satellite Laser Ranging (SLR) data. Although recent analyses of GRACE (Gravity Recovery and Climate Experiment) mission data of monthly C20 values since 2002 have shown high temporal correlations with LAGEOS results, significant differences still remain. As it is common practice in GRACE data processing to remove a priori the short-term nontidal atmospheric and oceanic induced variations of the gravity potential via the socalled Atmosphere and Ocean De-aliasing Level-1B (AOD1B) products, their use for LAGEOS data processing would allow a direct comparison of results and a rigorous combination of the solutions. Since the consideration of short-term non-tidal atmospheric and oceanic mass redistributions by means of AOD1B time series reveals a significant impact on LAGEOS data processing results, the AOD1B time series has been consistently prolongated back to the advent of LAGEOS-1 in 1976. An analysis for the period 1993-2006 leads to the major findings that the consideration of atmospheric and oceanic mass redistributions result in a considerably reduced seasonal signal in the LAGEOS C20 time series. This in turn reduces the correlation to GRACE significantly by about 30%. This is in opposite to what one would expect, i.e., a better agreement between GRACE and LAGEOS if common standards are applied. Thus, a LAGEOS solution corrected for short-term non-tidal atmosphere and ocean effects is much less sensitive to primarily annual hydrological mass variations than GRACE. In addition, significant semi-annual signals remain. Other indicators such as the unresolved bias between LAGEOS and GRACE in the order of 2·10-10 or LAGEOS orbits and Satellite Laser Ranging (SLR) observation residuals are hardly affected by the AOD1B model.

Description: Although the development of passive margins has been extensively studied over a number of decades, significant questions remain on how mantle and crustal dynamics interact to generate the observed margin geometries. Here, the Orange Basin, located on the south-west African continental margin is investigated. The basin fill is considered to comprise a classic rift-drift passive margin sequence recording the break-up of Gondwana and subsequent opening of the South Atlantic Ocean. Based on interpreted seismic reflection data, a 3D geological model was first constructed. Subsequently, an isostatic calculation (Airy´s model) using a homogeneous middle and lower crust was applied to this geological model to determine the position of the Moho for an isostatically balanced system. Isostatic sensitivity tests were applied to the model, and their gravity response was validated against different crustal structures for the basin. The best-fit model requires dense, presumably mafic material in the middle and lower crust beneath the basin and an abrupt change to less dense material near the coast to reproduce the observed gravity field. The passive margin of the South Atlantic shows typical features of a rifted volcanic continental margin, encompassing seaward dipping reflectors, continental flood basalts and high-velocity/density lower crust at the continent-ocean transition, probably emplaced during initial seafloor spreading in the Early Cretaceous. The Springbok profile offshore western South Africa is a combined transect of reflection and refraction seismic data. This thesis addresses the analysis of the seismic velocity structure in combination with gravity modelling and isostatic modelling to unravel the crustal structure of the passive continental margin from different perspectives. The velocity modelling revealed a segmentation of the margin into three distinct parts of continental, transitional and oceanic crust. As observed at many volcanic margins, the lower crust is characterised by a zone of high velocities with up to 7.4 km/s. The conjunction with gravity modelling affirms the existence of this body and at the same time substantiated its high densities, found to be 3100 kg/m³. Both approaches identified the body to have a thickness of about 10 km. Yet, the gravity modelling predicted the transition between the high-density body towards less dense material farther west than initially anticipated from velocity modelling and confirmed this density gradient to be a prerequisite to reproduce the observed gravity signal. Finally, isostatic modelling was applied to predict average crustal densities if the margin was isostatically balanced. The results imply isostatic equilibrium over large parts of the profile; smaller deviations are supposed to be compensated regionally. The calculated load distribution along the profile implies that all pressures are hydrostatic beneath a depth of 45 km. The presence of lower crustal bodies of high seismic velocities indicates that large volumes of igneous crust formed as a consequence of lithospheric extension. Furthermore, results of a combined approach using subsidence analysis and basin history inversion models are presented. The outcome shows that a classical uniform stretching model does not account for the observed tectonic subsidence. Moreover, it is found that that the thermal and subsidence implications of underplating need to be considered. Another departure from the uniform stretching model is renewed sub-crustal stretching and linked to that uplift in the Cenozoic which is necessary to reproduce the observed phases of erosion and the present-day depth of the basin. The dimension of these events has been examined and quantified in terms of tectonic uplift and sub-crustal stretching. Based on these forward models the heat flow evolution is predicted not only for the available real wells but also for virtual wells over the entire study area. Finally, the hydrocarbon potential and the temperature evolution is presented and shown in combination with inferred maturation of the sediments for depth intervals which comprise potential source rocks.

Description: One significant outcome of my thesis is an improved chronostraphigraphical framework for the glacial lacustrine unit of the Black Sea sediment cores, which allowed to refine the environmental history of the Black Sea region and enabled a reliable correlation with data from other marine and terrestrial archives. Data gathered along a N-S transect presented on a common time scale revealed coherent changes in the basin and its surrounding. [...] My PhD thesis is based on four manuscripts, published or submitted to peer-reviewed international journals, and one additional preliminary study.

Description: This study focuses on tectonics at the Neogene and late Quaternary time scales in the Main Cordillera and coastal forearc of the south-central Andes. For both domains I document the existence of previously unrecognized active faults and present estimates of deformation rates and fault kinematics. Furthermore these data are correlated to address fundamental mountain building processes like strain partitioning and largescale segmentation.

Description: This thesis aims to understand these changes and reasons behind by analyzing the styles of deformation of the western margin of South America, in particular the surface expression of deformation, along the Chilean convergent margin. To understand the parameters controlling the style of deformation in the chosen areas I applied 3D transient numerical modeling. This thesis represents the first real 3D study analyzing deformation caused by oblique convergence associated with a realistic composite rheology.

Description: Die tiefe Geothermie in Deutschland erschließt Reservoirs in 3 bis 5 km Tiefe mit Temperaturen von 100 °C bis 200°C. Für die Wandlung dieser Niedertemperaturwärme in elektrische Energie kommen voraussichtlich nur Kraftwerke mit Sekundärkreislauf in Frage. Die zwei zur Zeit verfügbaren Systeme, der Organic Rankine Cycle (ORC) und der Kalina-Prozess werden analysiert und bewertet. Die aus den Wasserdampfprozessen bekannten Methoden zur Verbesserung des Wirkungsgrades werden hinsichtlich ihrer Übertragbarkeit geprüft, alternative Möglichkeiten der Verbesserung untersucht und daraus praktikable Vorgehensweisen beim Entwurf der Prozesse entwickelt.

Description: The Central European Basin System is one of the basins where the sedimentary cover is strongly affected by salt tectonics. The most significant stage of salt movement occurred during the Triassic. The largest Triassic subsidence occurred in the different sub-basins surrounding the Ringkoebing-Fyn High such as the Horn Graben, the Danish Basin and the Glueckstadt Graben. Furthermore, the thickest Triassic succession is observed in the Glueckstadt Graben where it reaches more than 9000 m. In the present study, the structure and the Permian to recent evolution of the Glueckstadt Graben are investigated by use of borehole data, seismic lines and 3D structural modelling. The evaluation of the diverse deformation patterns of the sedimentary cover and their relations to salt structures show that the strongest salt movements occurred at the beginning of the Keuper when the Gluckstadt Graben was affected by extension. The onlap patterns of the Jurassic sediments onto the top of the Keuper succession indicate essential changes of the sedimentation style during the Jurassic. Thick Jurassic sediments are only observed around salt structures and are thinning away from salt walls or salt stocks. The Upper Cretaceous strata have an approximately constant thickness and the parallel reflections patterns indicate a quiet tectonic setting with very minor salt movements in the Late Cretaceous. Renewed salt flow during the Paleogene-Neogene caused rapid subsidence along the marginal parts of the Central Triassic Graben in the Westholstein, the Eastholstein and the Hamburger troughs. The thick Paleogene-Neogene strata within the marginal troughs may also be related to a regional component of tectonic subsidence in the area, contemporary with rapid subsidence in the North Sea. The 3D modelling approach has been used to determine salt distribution at certain paleo-levels in response to unloading due to sequential removing of the stratigraphic layers. The modelling approach was also aimed to reconstruct the original Permian salt distribution immediately after deposition. The initial salt thickness varies from 1300 m at the flanks of the basin up to 3000 m within the central part and demonstrates a clear NNE-SSW trend of the basin. The regional trend of the restored salt distribution points to a westward continuation of the Permian salt basin. The formation of the deep Central Triassic Graben and the subsequent Jurassic- Cenozoic marginal troughs was strongly controlled by the development of salt structures through time. It is shown that the depocentre of sedimentation was moving away from the central part of the of the original Graben structure towards its margins. The evaluation of the available data and results of the 3D reverse modelling demonstrate that a greater amount of subsidence occurred close to the active salt structures, and may have resulted in gradual depletion of Permian salt. Thus, this study indicates that the source of such long-term subsidence is derived from gradual depletion of the Permian salt, which started within the axial part of the basin and moved towards the basin flanks with time. In this sense, the Glueckstadt Graben was formed at least partially as a “basin-scale rim syncline” during post-Permian times. Therefore, the results show that salt withdrawal may have played an important role during the Meso-Cenozoic evolution and that the effects of salt-driven subsidence during the Meso-Cenozoic can be considered the main reason for the formation of the deep Central Triassic Graben and the subsequent Jurassic-Cenozoic marginal troughs.

Description: Das zentraleuropäische Beckensystem ist eines der Becken, in denen die Sedimentdecken stark durch Salztektonik beeinflusst sind. Die stärksten salztektonischen Aktivitäten traten während der Trias auf. Die größte triassische Subsidenz erfolgte in den verschiedenen Unterbecken rund um das Ringköbing-Fünen Hoch (Horn Graben, Dänisches Becken, Glückstadt Graben). Die mächtigste triassische Abfolge wurde im Glückstadtgraben beobachtet, wo sie mehr als 9000 m Mächtigkeit erreicht. In der vorliegenden Studie wurden die Struktur sowie die Entwicklung des Glückstadt Grabens vom Perm bis heute mit Hilfe von Bohrdaten, seismischen Linien und 3D-Strukturmodellierung untersucht. Die Auswertung der verschiedenen Deformationsmuster der Sedimentdecke und ihr Bezug zu Salzstrukturen zeigen, dass die stärksten Salzbewegungen am Beginn des Keupers, während einer Dehnung des Glückstadt Graben auftraten. Die jurassischen Sedimente zeigen dann eine grundlegende Änderungen der Sedimentationsart während des Jura an. Mächtige jurassische Sedimente treten nur rund um Salzstrukturen auf und dünnen mit zunehmender Entfernung von Salzmauern oder Salzstöcken aus. Die Oberkreideschichten haben eine annähernd konstante Mächtigkeit, und die parallelen Reflektionsmuster weisen auf eine ruhige tektonische Subsidenz mit geringen Salzbewegungen in der Oberkreide hin. Erneute Salzbewegungen während des Paläogens-Neogens verursachten schnelle Subsidenz entlang der Randbereiche des zentraltriassischen Grabens, den Westholstein, Ostholstein und Hamburger Trögen. Die mächtigen paläogen-neogenen Schichten innerhalb der Randtröge sind eventuell auch mit einer regionalen Komponente tektonischer Subsidenz verbunden, zeitgleich mit schneller Subsidenz in der Nordsee. Der 3D- Modellierungsansatz wurde genutzt, um die Salzverteilung für verschiedenen Paläolevels als Reaktion auf Entlastung durch sequentielles Entfernen der stratigraphischen Schichten zu bestimmen. Mit dem Modellierungsansatz wurde auch versucht, die ursprüngliche permische Salzverteilung unmittelbar nach der Ablagerung zu rekonstruieren. Die ursprüngliche Salzmächtigkeit variiert zwischen 1300 m an den Beckenflanken und bis zu 3000 m innerhalb des zentralen Teils und zeigt einen klaren NNO-SSW-Trend innerhalb des Beckens. Die Bildung des tiefen zentraltriassischen Grabens und der nachfolgenden jurassisch- känozoischen Randtröge wurde stark durch die langandauernde Entwicklung von Salzstrukturen kontrolliert. Es wird gezeigt, dass das Sedimentationszentrum sich vom Zentralteil der ursprünglichen Grabenstruktur in Richtung ihrer Ränder verlagerte. Die Auswertung der verfügbaren Daten und die Ergebnisse der 3D-Rückwärtsmodellierung zeigen, dass der größte Teil der Subsidenz nahe aktiver Salzstrukturen auftrat, und eventuell zu einer graduellen Abwanderung permischer Salze führte. Daher zeigt die Studie, dass die Ursache der langzeitigen Subsidenz die graduelle Abwanderung permischen Salzes ist, welche im axialen Teil des Beckens begann und sich im Laufe der Zeit in Richtung der Beckenflanken bewegte. In diesem Sinne wurde der Glückstadtgraben zumindest teilweise in nachpermischer Zeit als basin-scale rim syncline geformt. Daher zeigen die Ergebnisse, dass dieser Salzrückzug während der meso-känozoischen Evolution eine bedeutende Rolle gespielt haben dürfte, und dass die Effekte salzgesteuerter Subsidenz während des Meso-Känozoikums als Hauptursache der Bildung des tiefen zentraltriassischen Grabens und die nachfolgenden jurasso- känozoischen Tröge angesehen werden kann.

Description: This volume contains the results of the DESERT project running from 2000 to 2006. It opens with a review paper (DESERT Group, 2009) followed by 33 special papers, see list of content (529 pages).

Description: This study is aimed at a development of numerical method to model the dynamic geoid and the surface plate velocities induced by global mantle flow with the effect of strong lateral viscosity variations (LVV) in conjunction with the effects of selfgravitation and mantle compressibility. I employ the technique, which comprises the combination of the spherical harmonic method, the direct Godunov method used for solving the Stokes and Poisson equations in spherical harmonics with arbitrary boundary conditions, functions of density and radial viscosity, and the iterative method based on the principles suggested by Zhang and Christensen (1993) used for modeling the effect of LVV. The 3-D mantle viscosity model is based on the global seismic tomography model S20a converted to temperature variations. The maximum lateral viscosity contrast in the lithosphere-asthenosphere zone modeled reaches four orders of magnitude. It is found that the influence of LVV on the dynamic geoid is extremely significant: an alteration of the geoid figure due to LVV exceeds 45% of the maximum geoid undulations. The detailed analysis showed that the geoid is affected by both, strong LVV induced in the upper mantle and large-scale LVV induced in the lower mantle. According to the results of this study the separated effects of the upper- and lower-mantle LVV on the geoid figure are nearly additive with respect to the whole-mantle LVV and partly compensating with respect to each other. The mantle flows are strongly affected by LVV as well, especially by the long-wavelength viscosity variations in the lower mantle: global upwellings tend to intensify due to the effects of LVV, while downwellings become weaker. The alteration of the near-surface velocities reaches 30-40% in amplitude not only due to the LVV induced toroidal flow but also due to change in the spheroidal velocity component. I can conclude that the LVV presented in both, upper and lower mantle, play an important part in global modeling, therefore, an incorporation of 3-D viscosity structure into the next generation global dynamic models is a task of vital significance.

Description: A set of 59 seismological stations was deployed in the Central Andes region at 21°S (Chile-Bolivia) along a profile ~600 km long and were operated between 2002 and 2004. The teleseismic tomographic images (from P- and S- waves) show low-velocity anomalies that are interpreted as the effects of melting or fluids at both flanks of the Altiplano plateau. Beneath the Central Volcanic Zone (CVZ) a low-velocity anomaly is interpreted to be caused by fluids that are the origin of the volcanic material from the CVZ. A low-velocity anomaly in the upper crust is interpreted as the Altiplano Low-Velocity Zone that appears to extend as far to the east as the Eastern Cordillera. A high-velocity body between 100 km and 150 km depth is interpreted as being part of the old cold lithosphere that detached from the base of the crust. The Brazilian Shield is thought to be responsible for the strong high-velocity anomaly on the eastern side of the Central Andes. In addition, another set of 19 stations was deployed in the southern Argentine Puna along a profile ~200 km long and were run over the same period of time (2002-2004). The intention was to study the crustal thickness at 25.5°S, where delamination of the lithosphere was proposed to explain the higher elevation of the Puna plateau. Beneath the plateau a negative velocity anomaly is observed and interpreted here as being the location of fluid transfer between the deeper and shallower portions of the crust, that emanate from the Benioff zone at depths of ~200 km. This anomaly clearly divides in two branches: one to the west towards the volcanic arc (CVZ) and the other to the east where the back-arc volcanoes are located. On their way to lower depths, the fluid paths are probably influenced by the presence of nearby isotherms. The bifurcation of the ascending path could be related to the presence of the lithosphere-asthenosphere boundary (LAB) at ~100-130 km. Based on our observations, the type and form of the anomaly, it is possible to propose the presence of a return-flow type model for fluid ascent in contraposition to the assumed corner-flow model usually proposed for the Andes. The fluids that cause the seismic anomalies beneath the Puna plateau are generated at deeper levels in the asthenosphere and ascend parallel to the oceanic slab in the manner of a return-flow. In the crust and beneath the Salar de Antofalla (SA), a high-velocity block with seismic activity is interpreted as part of the old and cold Palaeozoic magmatic arc (Faja Eruptiva de la Puna Occidental). The presence of this block is may be responsible for the distribution of volcanic activity localized at both sides of this anomaly. Eastern of the SA, it is possible to recognize a zone with low-velocities beneath the Galan volcano. A sharp limit imposed by high velocities, probably related to metamorphic rocks from the Paleozoic basement (Tacuil and Luracatao ranges) can be detected on the east of the profile. A high-velocity block with seismic activity is located in the crust beneath the Salar de Antofalla (SA) and interpreted as part of the old and cold Palaeozoic magmatic arc (Faja Eruptiva de la Puna Occidental). This block might be responsible for the distribution of volcanic activity localized at both sides of this anomaly. Beneath the Galan volcano and east of the SA, a zone with low-velocities can be recognized. A sharp limit towards high-velocities can be observed on the east of the profile, probably related to metamorphic rocks from the Palaeozoic basement (Tacuil and Luracatao ranges).

Description: The joint project TIPTEQ (from The Incoming Plate to mega-Thrust EarthQake processes) refers to an integrated approach in order to investigate the processes active in the seismogenic coupling zone at the southern Central Chilean margin and to validate their importance for both the initiation of mega-thrust earthquakes and the evolution of the forearc. The lateral variability of these processes and related parameters is investigated along five marine corridors offshore the south Chilean continental margin. The northernmost marine transect is continued onshore with a reflection seismic survey at 38.2◦ S which crosses the hypocenter of the largest ever recorded earthquake, the 1960 Great Chilean earthquake (Mw = 9.5). The processing and structural interpretation of this high-resolution seismic data set is one major task of this thesis. Furthermore, a first-break tomography was conducted to construct a near-surface velocity model. Several tests to validate the tomographic images were conducted and the limitations of the data set and method were explored in detail. The reflection seismic transect lies in the center of an extensive geophysical program comprising magnetotelluric surveys and a large seismological network. An integrative interpretation with the results of the other geophysical groups of TIPTEQ concludes the thesis. The depth section of the TIPTEQ NVR data set shows the subducting Nasca plate below the segmented forearc and a highly reflective overriding South American plate down to a depth of 60 km. High reflectivity directly above the plate interface suggested to be associated with the existence of a subduction channel with a varying thickness of 2 - 5 km down to a depth of at least 38 km. It might continue towards depth. Local seismicity possibly defines the upper bound of the subduction channel. The continental Moho is not clearly imaged. However, one possible location is at 38 - 40 km depth given by the 1960 earthquake hypocenter. The Moho may be continued eastwards to a depth of 35 km where a prominent structure is imaged. This reflector coincides with the modeled Moho interface from a 3–D density model along the Chilean margin. The reflectivity east and above of the 1960 hypocenter area may exhibit alternative eastward continuations of the continental Moho. The position and extent of the continental mantle wedge changes accordingly. Major forearc features such as the crustal Lanalhue Fault Zone and a strong west-dipping reflector perpendicular to the plate interface can be observed. The reflectivity of the oceanic crust increases in depths below 35 km. This increase might be caused by fluid release due to the porosity collapse in basalt. The integrative interpretation links this observation with a zone of high Vp/Vs ratio calculated from the seismological velocity model. Combining all available data sets of seismological, magnetotelluric and gravimetrical findings results in a complex image of the southern Chilean subduction zone, which this thesis addresses to decode.

Description: [...] Studies regarding the theory of this correlation and how to handle it when estimating sub-daily polar motion together with nutation are included in the thesis. Furthermore, it is demonstrated that the common estimation of the terrestrial reference frame and EOPs can be employed to identify a mismatch between the local tie values and the estimated coordinate differences at co-located sites. Thus, the EOPs offer another independent evaluation of the LT values, as mentioned already above for the troposphere gradients. For the studies described in this thesis, it is of vital importance that continuous observations are available for all observation techniques. Therefore, the so-called CONT campaigns of the International VLBI Service for Geodesy and Astrometry (IVS) are well-suited. Such special campaigns with continuous VLBI observations for several days are initiated from time to time in order to demonstrate the full capabilities of VLBI. The studies described in the thesis at hand are based on the two-week CONT campaign scheduled in October 2002, named CONT02.

Description: In der vorliegenden Arbeit wird eine Schätzung der durch die ozeanische Gezeitendynamik induzierten Magnetfelder in einer Vorwärtsrechnung durchgeführt. Die Prädiktion basiert auf simulierten ozeanischen Strömungen aus dem OMCT-Modell, welches die globale ozeanische Dynamik beschreibt. Als weitere Eingangsdaten werden das Hintergrundmagnetfeld und die elektrische Leitfähigkeit der ozeanischen Sedimentschicht benötigt.

Description: A Databank was created using data from 25 local catalogues and 30 special studies of earthquakes in central, northern and northwestern Europe. Event types were discriminated, fake events and duplets eliminated, and different magnitudes and intensities converted to Mw. The conversions require the establishment of regression equations. The Catalogue contains tectonic events from the Databank within the area 44°N-72°N, 25°W-32°E and the time period 1300-1993 which have Mw magnitudes of 3.50 and larger. The area is covered by different polygons. Within each polygon only data from one or a small number of the local catalogues, supplemented by data from special studies, enter the Catalogue. If there are two or more such catalogues or studies providing a solution for an event, a priority algorithm selects one entry for the Catalogue. Then Mw is calculated from one of the magnitude types, or from macroseismic data, given by the selected entry according to another priority scheme. The origin time, location, Mw magnitude and reference are specified for each entry of the Catalogue. So is the epicentral intensity, I0, if provided by the original source. Following these criteria, a total of about 5,000 earthquakes constitute the Catalogue. Although originally derived for the purpose of seismic hazard calculation within GSHAP, the Catalogue provides a data base for many types of seismicity and seismic hazard studies.

Description: As part of this thesis, a new strategy for the inversion of stress states from fault-slip data is introduced (Chapter 2). This new approach is applied to data sampled from outcrops along the southern margin of the CEBS (Chapter 4) and from outcrops in the Oslo Graben area (Chapter 5). The results derived from these study areas deliver new insights into the evolution of paleostress fields that controlled the development of the entire CEBS.

Description: Dieser Report fasst Ergebnisse aus der Startphase des Projekts Nutzbarmachung klüftigporöser Speichergesteine zur abnehmernahen geothermischen Energiebereitstellung zusammen. Das Projekt wurde mit Förderung durch das BMBF (BEO 0327063B) in einer Vorphase 1998 und durch das BMWi (BEO 0327063) 1999 gestartet.

Description: This study presents methods and field experiments for ground-based GPS altimetry. Although Coarse/Acquisition Code (C/A-code) based methods are introduced, the main part of this work addresses the use of carrier phase-delay observations of the reflected GPS signal and focuses on specular reflection. [...] This study approves the feasibility of ground-based GPS altimetry with the OpenGPS receiver and with only one low-gain and wide field-of-view RHCP antenna using L1 carrier phase-delay observations of reflected GPS signals. The work shows the potential of GPS reflectometry for remote water level monitoring from a safe position in cases where in-situ measurements are not possible, are dangerous or sensors may get destroyed by the highly dynamic sea or glacier environment.

Description: Das Ziel dieser Arbeit ist es, die Mechanik im Bereich des forearcs der Makran Subduktionszone zu untersuchen. Zu diesem Zweck kommen drei verschiedene Simulationstechniken zum Einsatz. Dies sind die Finite und die Diskrete Elemente Methode als zwei numerische Verfahren, sowie analoge Sandexperimente. Durch die Kombination dieser drei Methoden, die sich ergänzende und vergleichende Ergebnisse liefern, wird ein umfassendes Bild der Deformations- und Massentransferprozesse des forearcs in Makran gewonnen. Zudem ermöglichen alle drei Verfahren die Untersuchung des Deformationsverhaltens in einem Material, welches einer Mohr-Coulomb Rheologie mit strain hardening/strain softening bzw. einem work hardening gehorcht.

Description: Deformation processes in the early deformation stages of thrusting in growing fold-and-thrust belts and the role of factors controlling and localizing the deformation are still not well understood. There are only few natural examples or experimental studies to allow the identification of factors controlling initial states of deformation. In particular, the spatial interactions in curved fold-and-thrust belts or in segments striking obliquely to the convergence direction are rarely systematically examined. The Boomerang Hills Region (BHR), located at the eastern flank of the Central Andes close to the axis of the Bolivian Orocline, is an appropriate area to study such problems. There, oblique contraction is caused by a south-dipping basement interacting with a WSW-ENE to SW-NE convergence direction. In order to infer the controlling factors of deformation, the structural pattern associated with the active development of a new thrust sheet and the structural history of the adjacent foreland was examined. The detailed spatial-temporal relationships of Andean and pre-Andean structures within the BHR were investigated using a dense network of 100 reflection-seismic profiles for subsurface interpretation and structural modeling. In addition, satellite images and drainage pattern were interpreted to infer neotectonic activity. Modeling techniques included cross section balancing for validation and quantification of geological processes, horizon unfolding for kinematical interpretation, and critical taper estimates to derive the possible dynamic status. Results show that the main factor controlling the evolution of the Boomerang Hills Thrust Unit and the eastern flank of the Bolivian Orocline are paleogeographic features. The crystalline basement of the BHR comprises an inherited structure of several syn- and antiforms. Some of these structures were partly reactivated as minor reverse faults with associated small folds in the sedimentary cover at an early stage of the Tertiary foreland basin evolution. Basement faulting is probably a result of spatial problems linked to the initiation of a foreland basin in a heterogeneous crust. WNW-ESE striking normal faults were active in the foreland of the BHR in the Late Tertiary and show maximum activity during the intermediate state of foreland basin sedimentation. Further to the north, closer to the Brazilian Craton, normal faults are presently active. Foreland extension sums to 1.1%-1.5% and results from minor flexural extension due to bending of the Brazilian Shield lithosphere through Andean orogenic loading. The southern part of the BHR is represented by a young, evolving thrust sheet. Two zones can be differentiated along the Andean deformation front: (1) a W-E to NW-SE-striking frontal segment of predominantly orthogonal shortening, comprising a thrust / anticline system and accommodating at least 1400- 2000 m horizontal shortening on the basal decollement ; (2) A WSW-ENE-striking lateral zone of oblique shortening comprised by a complex system of thin-skinned strike-slip faults and minor folds. The deformation front always follows a pronounced edge in the topography of the top basement surface close to the boundary of the Paleozoic basin. Usually, faults are located close to asperities in the top basement surface; fold axes trend parallel to the contours of basement depth. The orientation of the deformation front as well as the laterally varying structural style is the result of deformation localization and strain partitioning. Because of the impossibility to accommodate non-orthogonal contraction by oblique faulting close to the surface, strain partitioning must occur along the deformation front. Consequently, a N 35°E thrusting direction is divided into orthogonal and tangential components, both with respect to the orientation of the deformation front and to depth contours of the basement. The two components are accommodated by convergent and strike-slip structures, respectively, which join via a common detachment horizon. The Boomerang Hills Thrust Unit is affected by left-lateral shear as interpreted from the particle displacement field of an unfolded horizon. This shear is invoked by the spatially distributed accommodation of thrust movement along the obliquely striking deformation front. The N 35° thrusting direction of the Boomerang Hills Thrust Unit represents the orthogonal component of strain partitioning caused by the WNW-ESE orientation of the Subandean Zone with respect to a WSW-ENE convergence between the Andes and the Brazilian shield. The tangential component is compensated at the back of the Boomerang Hills Thrust Unit where a positive flower structure is present and strain partitioning is made possible via the detachment horizon. Critical taper analysis shows that thrusting on the south-dipping basement is possible without any substantial internal deformation due to the wedge shape of the sedimentary prism. Therefore, the most important factor controlling the localization of the deformation front is the loss of critical taper at a pronounced edge along the Paleozoic basin boundary. Secondary reasons for deformation localization are small asperities in/close to the top of the basement, e.g. small folds of the early foredeep evolution. Strain partitioning may also play a major role for the evolution of the eastern border of the Bolivian Orocline and in other curved fold-and-thrust belts as discussed for natural and experimental examples. Generally, orthogonal accreting segments evolve faster than obliquely orientated segments due to strain partitioning at the deformation front, hence leading to an increase in the curvature of the belt. Strain partitioning itself is caused by the orientation of the deformation front with respect to the shortening direction. Thus, factors controlling the localization of the deformation front, i.e. paleogeographic features, dominantly control the evolution of curved fold-and-thrust belts. For the eastern flank of the Bolivian Orocline it is postulated that an early Paleozoic rift basin exerts paleogeographic control on Andean deformation, leading to the WNW-ESE orientation of the Subandean Zone between the Chapare and Santa Cruz. Based on map interpretation it is suggested that (a) the previously assumed style of deformation using main thrusts is questionable for this segment of the Andes and (b) deformation involving basally accreting foredeep sediments has to be taken into account. Previously assumed estimates of shortening for the Chapare area in the northern limb of the Bolivian Orocline may therefore be significantly low.

Description: As a technical memorandum for the TIGA/SEAL project, this report describes the procedure and scheme of GPS data processing and product provision at GFZ for monitoring the vertical motion at tide gauge benchmarks to study the global eustatic sea level change. As one of the TIGA analysis centers (TAC), GFZ is processing data from about 370 GPS stations in three lines: backward reprocessing till 1994, forward processing with 66-week latency and one-week delay processing in parallel with IGS as part of IGS activities. The quality of the station coordinate solutions is assessed by comparing with o±cial IGS combination solutions and other TACs' solutions. The consistency with IGS solutions is 4 - 1 mm in the horizontal components, and 8 - 4 mm in the height component, improving with time. The larger discrepancy in earlier time indicates the improvement of TIGA reprocessing. The consistencies with other TACs are not as good as that with IGS. This may come from twofold effects. On the one hand, GFZ TIGA solutions also contribute to IGS. So, the IGS combination solutions should be internally consistent with GFZ TIGA solutions to a certain extent. On the other hand, the differences on software package, strategy and the size of network may also cause a worse consistency among each other. However, the combination of various TACs' solutions gives feedback to improve the single contribution and by this the final products.

Description: In this report we describe the new repeat station network, the measurements and some tests regarding the use of the variometer recordings for data processing, and we present the results of this latest German magnetic survey.