ALBERT

Description: The ability of any satellite gravity mission concept to monitor mass transport processes in the Earth system is typically tested well ahead of its implementation by means of various simulation studies. Those studies often extend from the simulation of realistic orbits and instrumental data all the way down to the retrieval of global gravity field solution time-series. Basic requirement for all these simulations are realistic representations of the spatio-temporal mass variability in the different sub-systems of the Earth, as a source model for the orbit computations. For such simulations, a suitable source model is required to represent (i) high-frequency (i.e., subdaily to weekly) mass variability in the atmosphere and oceans, in order to realistically include the effects of temporal aliasing due to non-tidal high-frequency mass variability into the retrieved gravity fields. In parallel, (ii) low-frequency (i.e., monthly to interannual) variability needs to be modelled with realistic amplitudes, particularly at small spatial scales, in order to assess to what extent a new mission concept might provide further insight into physical processes currently not observable. The new source model documented here attempts to fulfil both requirements: Based on ECMWF’s recent atmospheric reanalysis ERA-Interim and corresponding simulations from numerical models of the other Earth system components, it offers spherical harmonic coefficients of the time-variable global gravity field due to mass variability in atmosphere, oceans, the terrestrial hydrosphere including the ice-sheets and glaciers, as well as the solid Earth. Simulated features range from sub-daily to multiyear periods with a spatial resolution of spherical harmonics degree and order 180 over a period of 12 years. In addition to the source model, a de-aliasing model for atmospheric and oceanic high-frequency variability with augmented systematic and random noise is required for a realistic simulation of the gravity field retrieval process, whose necessary error characteristics are discussed. The documentation of the updated ESA Earth System Model (updated ESM) for gravity mission simulation studies is organized as follows: The characteristics of the updated ESM along with some basic validation is presented in Volume 1. A detailed comparison to the original ESA ESM (Gruber et al., 2011) is provided in Volume 2, while Volume 3 contains the description of a strategy to derive realistic errors for the de-aliasing model of high-frequency mass variability in atmosphere and ocean.

Description: [...] In this thesis it is shown that the epoch-differenced ionospheric delay correction is sufficient for estimating the tropospheric delay, e.g., the Zenith Total Delay (ZTD), from SF GPS data. Based on this result, the Satellite-specific Epoch-differenced Ionospheric Delay model (SEID) was developed. In the SEID model the ionospheric corrections for SF data are generated from the observations of surrounding reference stations equipped with DF receivers. With the derived ionospheric corrections and the SF data, pseudo L2 data are generated, which can be processed using existing GPS processing software packages without any changes. [...]

Description: The seismicity data file used for this study is represented by the earthquake catalogue CENEC for Europe north of 44°N (Grünthal et al. 2009a). This paper describes in detail how this homogeneous data file in terms of moment magnitudes Mw (with Mw greater than 3.5) has been derived. The degree of harmonization achieved in CENEC is quantitatively analysed in Grünthal et al. (2009b).

Description: The integrated plate boundary in Chile (IPOC) combines 15 broadband stations with strong-motion sensors, GPS, strain sensors and magneto-telluric stations. The Chilean subduction zone setting provides a high background rate of seismicity (crustal, intermediate depth, and plate interface) in a region with exceptionally low ambient noise, particularly at higher frequencies. We have deployed seismic mini-arrays in the vicinity of IPOC stations PB02 and PB07, and installed a third array to the east of these stations near the village of Quillagua, such that all three arrays form a triangle. Each array has 10 elements and an aperture in the km range. The study area lies just to the north of the northern boundary of the rupture area of the Tocopilla earthquake of 2007 Mw=7.7) and just above or slightly to the east of the downdip limit of plate interface seismicity. Installing the mini-arrays in the area of the existing IPOC has the following advantages: • Independent knowledge of background structure and seismicity from existing and ongoing studies. • Should any transients or other unusual signals be found in the array data, we can look for anomalous signals in geodetic and MT recordings, which will help to narrow down possible underlying mechanisms.

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 guidebook contains a thematic description an background information for each field day. The overall setting and development of the Saxo-Thuringian zone within the Variscan orogen is presented in Kroner and Romer (2010). This material is not included in this guide book (because of copyright reasons) and will be handed out to field trip participants as separate handout.

Description: Film 2: "Geological Conditions and Capacities" (Length 06:00) "Porous rocks with good permeability have, in Germany and world-wide, the highest potential for geological CO2 storage. ..." Where do these rocks occur? And which further criteria need potential CO2 storage sites to meet? Production Year: 2010-2012

Description: The 9th TRACE conference (Tree Rings in Archaeology, Climatology and Ecology) was organized by the Institute for Forest Growth, University of Freiburg, on April 22nd – 25th 2010 in Freiburg, Germany. [...] This volume of TRACE Proceedings contains 26 short papers and gives an overview of the wide spectrum of fields in tree-ring research.

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: Film 5: "Ketzin Pilot Site" (Length 05:05) "At the Ketzin pilot site in Brandenburg, Germany, CO2 has been injected into an underground storage formation since June, 2008. ...". The monitoring methods used at the pilot site Ketzin are among the most comprehensive in the field of CO2 storage worldwide. Important is the combination of different monitoring methods, each with different temporal and spatial resolutions. Which methods are used? And what have we already learned? Production Year: 2011-2012

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: Passive continental margins offer the unique opportunity to study the processes involved in continental extension and break up as well as the role of hot-spot related magmatism. We conducted combined on- and offshore seismic experiments in Northern Namibia designed to characterize the Southern African passive margin at the interaction with the Walvis Ridge, to assess the interaction of the presumed plume with continental lithosphere and to determine the deep structure of the transition from the coastal fold belt to the stable craton, where the Walvis Ridge hits the African continent. The seismic project integrated three experiments, (A) an onshore, coast-parallel refraction seismic profile, (B) two onshore-offshore wide-angle seismic transects, and (C) a combined on- and offshore seismic experiment to image the sub-Moho velocity (Pn tomography) at the ocean-continent transition (Fig. 1). The knowledge of the lithospheric structure of the margin together with results from other geoscientific studies (e.g., conducted within the SPPSAMPLE, DFG Priority Program 1375, South Atlantic Margin Processes and Links with onshore Evolution) will help to address fundamental questions such as, how continental crust and plume head interact, what the extent and volumes of magmatic underplating is, and how and which inherited (continental) structures might have been involved and utilized in the break-up process.

Description: This thesis summarizes the results of the WSM project’s second phase (1996‐2008). In particular it presents the major achievements that have been accomplished with the WSM 2008 database release that has been compiled under the guidance of the author. Furthermore, the thesis briefly presents three of the author’s numerical models that aim at quantification the temporal changes of the crustal stress field.

Description: This publication is a result of the 12th TRACE conference (Tree Rings in Archaeology, Climatology and Ecology) organized by the Department of Agriculture, Forests, Nature and Energy (DAFNE) of the Università della Tuscia (Viterbo, Italy) on May 08th – 11th 2013 in Viterbo, Italy. [...] A total of 20 manuscripts were submitted. After review 19 short papers are published in this volume, giving an overview of the wide spectrum of fields in tree-ring research.

Description: [...] In context of this work, a new damage mechanism is proposed: the mechanically induced fracture face skin. This new mechanism results from mechanical interactions between the proppants and the reservoir rock, due to the increasing stress on the rock-proppant system during production. Proppant embedment into the fracture face and proppant crushing leads to fines production and can impair the fracture performance. In order to achieve sustainable, longterm productivity from a reservoir, it is indispensable to understand the hydraulic and mechanical interactions in the rock-proppant system. In order to analyse the hydraulic and mechanical interactions, laboratory experiments using three different flow cells were conducted. These flow cells were used to localise and quantify the mechanical damage at the fracture face, as well as to investigate the long-term stability of a rock-proppant system under in-situ reservoir conditions. [...]

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: 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: This study represents the first investigating potential kinematic boundary conditions for subduction erosion in a systematic manner. For the subduction erosional process, the aperture at the box's rear, which allowed rearward material loss, was shown to have the largest influence on obtained results. If the amount of material leaving the system was larger than the amount of material subducted at the wedge's toe, the margin evolved as erosional. We found the surface slope to be the second important parameter, which strongly controls the amount of basally eroded material.

Description: This short report describes the first attempt at obtaining a preliminary cross-border risk model for Central Asia starting from datasets that were already available at the beginning of the EMCA Project.

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: This volume contains 23 short papers which summarise the main subjects of talks and posters presented at the eighth TRACE (Tree Rings in Archaeology, Climatology and Ecology) conference organized by Jožica Gričar, Tom Levanič, Špela Jagodic, Robert Krajnc and Polona Hafner and held in Otočec, Slovenia on April 16th - 19th, 2009.

Description: This document serves as a record of the processing standards, models & parameters adopted for the generation of monthly and weekly (aligned to GPS weeks) Level-2 gravity field data products by the GRACE Science Data System component at the GFZ German Research Centre for Geosciences.

Description: SEG-Y data of small-scale high-resolution controlled-source seismic experiment to investigate the mesoscopic fault structure of the Wadi Arava fault, Dead Sea Transform.

Description: In order to analyze mineralogical-geochemical changes occurring in whole rock reservoir samples (Stuttgart Formation) from the Ketzin pilot CO2 storage site, Brandenburg/Germany as well as to investigate single fluid-mineral reactions laboratory experiments and geochemical modeling were performed. The whole rock core samples of the Stuttgart Formation were exposed to synthetic brine and pure CO2 at experimental P-T conditions and run durations of 5.5 MPa/40 °C/40 months for sandstone and 7.5 MPa/40 °C/6 months for siltstone, respectively. Mineralogical changes in both sets of experiments are generally minor making it difficult to differentiate the natural variability of the whole rock samples from CO2-induced alterations. Results of sandstone experiments suggest dissolution of analcime, anhydrite, the anorthite component of plagioclase, chlorite + biotite, hematite and K-feldspar. Dissolution of anhydrite, the anorthite component of plagioclase and K-feldspar is also observed in siltstone experiments. During equilibrium simulations best matching models were ranked based on a mathematical statistical dispersion relation. The best matching model comprises a mineral combination of the albite component of plagioclase, anhydrite, dolomite, hematite, and illite. The equilibrium modeling showed that it is difficult to match K+, Fe2+ and SO4 2- brine concentrations simultaneously. The best matching subsets of the equilibrium models were finally run including kinetic rate laws. These kinetic simulations reveal that experimentally determined brine data was well matched, but reactions involving K+ and Fe2+ were not completely covered. Generally larger mismatches for dissolved Al3+ and Si4+ in all the completed simulations are most likely related to the sampling strategy and respective inaccuracies in the measured concentrations of dissolved Al3+ and Si4+. The kinetic simulation suppressing mineral precipitation yields best matches with experimental observations. The modeling shows acceptably well matches with measured brine ion concentrations, and the modeling results identified primary minerals as well as key chemical processes. It was also shown that the modeling approach is not capable of completely covering complex natural systems. Experiments on mineral separates were conducted with 2 M NaCl brine and pure CO2 using siderite, illite and labradorite samples. Experimental P-T conditions were 20 (30) MPa and 80 °C; run durations were one (siderite), two (illite) and three weeks (labradorite), respectively. Based on the acquired set of mineralogical-geochemical data the distinct experiments show: (i) dissolution of ankerite and stable siderite, which is therefore interpreted to be a potential CO2 trapping phase, (ii) preferred dissolution of the Ca-smectite component out of the illite-smectite mixed-layer mineral and (iii) dissolution of labradorite, respectively. No mineral precipitates (e.g. carbonate phases) were detected in any of the conducted laboratory experiments, and only one single kinetic simulation predicts the formation of minute amounts of dolomite. Based on the data acquired during this dissertation the mineralogical-geochemical effects of CO2 are minor, and the (chemical) integrity of the Ketzin reservoir system is not significantly affected by injected CO2.

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: The ability of any satellite gravity mission concept to monitor mass transport processes in the Earth system is typically tested well ahead of its implementation by means of various simulation studies. Those studies often extend from the simulation of realistic orbits and instrumental data all the way down to the retrieval of global gravity field solution time-series. Basic requirement for all these simulations are realistic representations of the spatio-temporal mass variability in the different sub-systems of the Earth, as a source model for the orbit computations. For such simulations, a suitable source model is required to represent (i) high-frequency (i.e., sub-daily to weekly) mass variability in the atmosphere and oceans, in order to realistically include the effects of temporal aliasing due to non-tidal high-frequency mass variability into the retrieved gravity fields. In parallel, (ii) low-frequency (i.e., monthly to interannual) variability needs to be modelled with realistic amplitudes, particularly at small spatial scales, in order to assess to what extent a new mission concept might provide further insight into physical processes currently not observable. The new source model documented here attempts to fulfil both requirements: Based on ECMWF’s recent atmospheric reanalysis ERA-Interim and corresponding simulations from numerical models of the other Earth system components, it offers spherical harmonic coefficients of the time-variable global gravity field due to mass variability in atmosphere, oceans, the terrestrial hydrosphere including the ice-sheets and glaciers, as well as the solid Earth. Simulated features range from sub-daily to multiyear periods with a spatial resolution of spherical harmonics degree and order 180 over a period of 12 years. In addition to the source model, a de-aliasing model for atmospheric and oceanic high-frequency variability with augmented systematic and random noise is required for a realistic simulation of the gravity field retrieval process, whose necessary error characteristics are discussed. The documentation is organized as follows: The characteristics of the updated ESM along with some basic validation are presented in Volume 1 of this report (Dobslaw et al., 2014). A detailed comparison to the original ESA ESM (Gruber et al., 2011) is provided in Volume 2 (Bergmann-Wolf et al., 2014), while Volume 3 (Forootan et al., 2014) contains a description of the strategy to derive a realistically noisy de-aliasing model for the high-frequency mass variability in atmosphere and oceans. The files of the updated ESA Earth System Model for gravity mission simulation studies are accessible at DOI:10.5880/GFZ.1.3.2014.001.

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: The ionosphere is a part of the upper atmosphere stretching from a height of about 60 km to more than 1 000 km. A certain fraction of the gas particles in that region is ionised by solar extreme ultra violet radiation. Since electromagnetic waves are influenced and significantly modified by ionospheric free charge carriers, the altitude range is of great scientific interest. GPS satellites emit electromagnetic waves on L – band frequencies travelling through the ionosphere and lower neutral atmosphere. Subsequently, they are received by low–Earth orbiting satellites. Consequently, the signals are affected by strong electron density gradients at altitudes above approximately 80km and by atmospheric density, pressure and water vapour content in the troposphere and stratosphere. This measurement method is termed radio occultation technique and it allows to receive a global picture of ionospheric and lower neutral atmospheric conditions. This study focusses on the detection and analysis of sporadic E layers from GPS radio occultation measurements on a global scale. Sporadic E layers are localised patches of relatively high electron density appearing in the E region of the ionosphere. They are represented in GPS signals as intense fluctuations. This work reveals that global sporadic E occurrence rates underlie variations on different time scales. It is demonstrated that the sporadic E occurrence depends on several geophysical parameters and it is subject to coupling processes between the neutral atmosphere and ionosphere. For example, the global sporadic E occurrence is oriented along Earth’s magnetic field. It is shown additionally that sporadic E altitudes are subject to tidal winds and that its annual cycle varies with meteor influx.

Description: The magnetic field of the Earth varies in space and time. Geomagnetism as research area that aims to describe and understand the sources of these variations is supported by two pillars: first, regular high-precision measurements in the global network of magnetic observatories and repeat stations are necessary to register the field and its variations at all. Second, mathematical methods are required in order to extract magnetic field models from this large data set. Methods applied to data offer insights in the mechanisms generating the magnetic field. This thesis covers both subjects. In a first part, following the description of the state of the art in observatory instrumentation, I explain in detail two instruments that have the potential to streamline the classical procedures: The Geomagnetic AUtomated SyStem GAUSS paves the way to automated absolute measurements, up to now only possible manually. The newly developed DI3 technique improves and simplies the standard manual measurements signicantly and thus reduces the requirements placed on observers. The second part deals with the mathematical tools available for geomagnetic field modelling. I focus on harmonic splines that can be derived from the classical approach of spherical harmonics. These base functions are interpolatory and have a localised shape while satisfying Laplaces equation. Hence, they are applicable to fit data regionally or globally. The harmonic splines are used with a data set made of repeat station and observatory measurements from Southern Africa. This region is of special interest because the field intensity is very low and and both spatial and temporal field gradients exist. Subdivided into an analysis of ancient (years 1961-2001) and recent (2005-2009) data, two continuous regional field models SAMS and X-SAMS are derived. From the analysis of the field models, a better understanding of the field behaviour is gained. Finally, the harmonic splines are used in a case study on globally distributed secular variation data. Rotating the data set in a system of coordinates aligned with the dipole axis and modelling it with the harmonic splines reveals the external origin of observed fast variations.

Description: The Institute of Seismology, University of Helsinki (ISUH) was founded in 1961 as a response to the growing public concern for environmental hazards caused by nuclear weapon testing. Since then ISUH has been responsible for seismic monitoring in Finland. The current mandate covers government regulator duties in seismic hazard mitigation and nuclear test ban treaty verification, observatory activities and operation of the Finnish National Seismic Network (FNSN) as well as research and teaching of seismology at the University of Helsinki. The first seismograph station of Finland was installed at the premises of the Department of Physics, University of Helsinki in 1924. However, the mechanical Mainka seismographs had low magnification and thus the recordings were of little practical value for the study of local seismicity. The first short-period seismographs were set up between 1956 and 1963. The next significant upgrade of FNSN occurred during the late 1970’s when digital tripartite arrays in southern and central Finland became fully operational, allowing for systematic use of instrumental detection, location and magnitude determination methods. By the end of the 1990’s, the entire network was operating using digital telemetric or dial-up methods. The FNSN has expanded significantly during the 21st Century. It comprises now 36 permanent stations. Most of the stations have Streckeisen STS-2, Nanometrics Trillium (Compact/P/PA/QA) or Guralp CMG-3T broad band sensors. Some Teledyne-Geotech S13/GS13 short period sensors are also in use. Data acquisition systems are a combination of Earth Data PS6-24 digitizers and PC with Seiscomp/Seedlink software or Nanometrics Centaurs. The stations are connected to the ISUH with Seedlink via Internet and provide continuous waveform data at 40 Hz (array) or 100-250 Hz sampling frequency. Further information about instrumentation can be found at the Institute’s web site (www.seismo.helsinki.fi). Waveform data is available from the GEOFON data centre.

Description: Reinsch et al. (2013) describe the installation of a novel fibre optic cable behind the anchor casing of the geothermal well HE-53, Hellisheiði geothermal field, SW Iceland. Within this data publication, DTS temperature data, acquired together with optical time domain reflectometry (OTDR) data during three different field campaigns are presented. Data have been acquired during the installation in spring 2009, during the onset of a production test in summer 2009 and after a 8.5 month shut-in period in summer 2010.

Description: [...] In this thesis, data from seismic and infrasound stations were analyzed in order to see effects of tsunamis of the great Sumatra-Andaman 2004 and Tohuku-Oki 2011 earthquakes. Data used are from seismic stations of the Global Seismic Network (GSN) around the Indian and Pacific oceans and from infrasound stations of the International Monitoring System of the Comprehensive Test Ban Treaty Organization (IMS/CTBTO). In both data sets, seismic and infrasound, tsunami signals are observed in the period range of 500to2000s. These data may add to two new very useful observables for tsunami early warning systems. [...]

Description: We recover coseismic static surface deformation by double integration of strong motion accelerometric data. Compared to GPS measurement, the advantage of strong motion data is that they have the potential to provide real-time coseismic static displacements. Strong motion data, however, has the classic problem of baseline offsets which produce unrealistic displacements after double integration is applied. We adopted a bilinear line fitting of empirical baseline correction method to overcome such problem. We investigate the improvement methods of baseline correction that constrain the maximum flatness of the displacement trace and use the cumulative energy ratio as a threshold. We apply the methods to data sets of the 2003, Mw 8.3 Tokachi-Oki earthquake, the 2007, Mw 7.7 Tocopilla earthquake, the 2010, Mw 7.8 Mentawai earthquake and the 2011, Mw 9.0 Tohoku earthquake. We show that, in general, the results of strong motion derived displacements are comparable to nearby GPS data for most data sets, although for far-field data the method may lead to poor results. It confirms that cumulative energy ratio is appropriate to be used as a threshold of baseline correction method. The very large and very good quality of boreholes strong motion data of the Tohoku earthquake gives opportunity to investigate the method deeply. We analyze the dependency of the method on hypocenter distance, magnitude and rupture model of the earthquake. We found that the method has a strong dependency on the given parameters, particularly on hypocenter distance. We also show that the method should be distinguished for horizontal and vertical components. Using our improvement method in this study, the deviations of vector length between strong motion derived displacements and nearby GPS data either for horizontal or vertical components, are significantly minimized. Further study, we optimize the use of valuable rapid static displacement data obtained from strong motion or GPS near-source station. We introduce a centroid grid search method to calculate the moment magnitude by using Okada (1985) model. Our method calculates reasonable moment magnitude using data even only from single station. This method can be done very rapidly within about 5 minutes. It provides crucial information e.g. for making tsunami warning decision.

Description: [...] We develop a regularizing solution procedure accounting for recent theoretical stability estimates. The capabilities of the procedure are shown for a single magnetic field component of the spherical harmonic field expansion beginning from the year 1900 by varying the mantle conductivity model and the degree of smoothness in the regularization. As an example, the radial component of a global (5,5) core-mantle boundary field is calculated for two epochs.

Description: [...] The approach followed in this study is based on the detailed analyses of the relationships between thermal conductivity of rock-forming minerals, which are most abundant in sedimentary rocks, and the properties measured by standard logging tools (i.e., gamma ray, density, sonic interval transit time, hydrogen index, and photoelectric factor). By using multivariate statistics separately for clastic, carbonate and evaporite rocks, the findings from these analyses allow the development of prediction equations from large artificial data sets that predict matrix thermal conductivity within an error of 4 to 11%, without being affected by the limitations mentioned above.

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: The focal point of my thesis is the extraction of climatic signals archived in stalagmites from NE India. High uranium concentration in the stalagmites ensured excellent age control required for successful high-resolution climate reconstructions. Stable isotope (δ18O and δ13C) and grey-scale data allow unprecedented insights into millennial to seasonal dynamics of the summer and winter monsoon in NE India.

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: 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.

Description: HALO_GPS is a precise GPS kinematic positioning software. It was developed at GFZ Potsdam for the German HALO project. The goal is to develop a software which is able to achieve cm-level accuracy for an aircraft trajectory for application in airborne gravimetry.

Description: Beneath the Pamir and Hindu Kush mountains an earthquake zone is observed in 80 to 300 km depth. It resembles in form and intensity the intermediate depth seismicity in subduction zones, here lithosphere is recycled in the Earth’s mantle. The fundamental tectonic concept of subduction is well established for convergent margins including an oceanic plate. The Pamir, however, is situated in an intra-continental setting and is formed during a continent-continent collision. This thesis aims to contribute to the investigation of the active tectonic process underlying the local occurrence of the seismicity in upper mantle depths. The field experiment for this study was performed in the framework of the multidisciplinary TIPAGE project from 2008 to 2010 and included large parts of the Pamir, the adjacent Tajik Depression and the Southern Tien Shan. The receiver function technique was applied to detect and locate seismic discontinuities in the subsurface in order to perform seismic imaging. The results clearly attest to an intra-continental subduction. Beneath the Pamir, the subducting plate is of Eurasian provenance. A southerly dipping 10 to 15 km thick low velocity zone could be resolved along a north-south profile in the eastern Pamir framing the earthquake zone in the upper mantle. This low velocity zone appears to be connected to the lower crust north of the seismic zone indicating subduction of crustal material in north to south direction. West of this north-south profile the zone of intermediate depth seismicity describes an arc changing its strike from east-west beneath the eastern Pamir to north-south beneath the western Pamir. Thereby the dipping direction of the slab changes from due south to due east. The geometry of this slab is confirmed by various receiver function cross sections. Towards western direction the subducted slab is connected to the crust of the Tajik Depression, indicating that the slab is the western extension of the Tajik Depression plate. Since the crustal thickness of the Tajik Depression is determined to at least 40 km, a continental composition for the crust of the Tajik Depression is inferred even though its underlying mantle lithosphere appears to be thin. The crustal thickness is mapped for the whole region. The resulting Moho map shows a 65 to 75 km thick crust in the Pamir and a 40 to 45 km thick crust in the surrounding basins. The arcuate subduction of the Tajik Depression plate and its eastern extension is reflected by characteristic Moho depth anomalies along the arc.

Description: Within this thesis, passive seismic data collected during the two-year TIPAGE deployment in Tajikistan and Kyrgyzstan from 2008 to 2010, are analyzed. This is the first modern digital seismological dataset for this politically unstable region, all previous studies either relied on globally recorded data or some short-term deployments of analog stations in Afghanistan during the late 1960s and 70s. Modern seismological techniques applied to the collected digital seismic data provide a wealth of new constraints on regional crustal and sub-crustal structure, leading to a better understanding of active tectonic processes.

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: 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: The amplitude spectra of global geophysical phenomena were investigated to motivate research of physical connections between them. The suggested causality was derived from comparison of the spectra, and from cross correlation functions. The following global parameters were discussed: for the earth rotation by the variations of the length of day, for the gemagnetic variation by the global field intensity, changes of the dipole axis and the westward drift, and for climate change by the atmospheric excitation function derived from air pressure variations, and temperature variations. The model of atmospheric excitation, which can be proved most exactly for the annual variation of length of day, is responsible for the 11 and 22 years periods, too. It failed for longer periods e. g., partially for the 30 years periods and completely for the 60 to 80 years periods, which were also discovered in the mean temperature and geomagnetic field variations. Therefore, it was suggested that longer periods in climate change and in the variations of the earth's rotation are caused independently by the same process in the earth core, provided that a physical influence of the geomagnetic field on climate will be accepted in future. The investigation was completed by comparison with the spectra of some local temperature variations in Europe.

Description: For the present work we carry out our research with two objectives : (A) Constructing a high resolution three-dimensional velocity model of the upper mantle. (B) Probing convection and deformation of the mantle through analysis of seismic anisotropy. In our study we determine the three dimensional Sv wave speed and the azimuthal anisotropy model by analyzing vertical component multimode Rayleigh wave seismograms. We use data of broadband stations within and around China. We construct the three dimensional model using a two step procedure.

Description: The present work tries to condense the state‐of‐the‐art for the exploration and exploitation of geothermal energy. Although a lot of experiences from different sites worldwide are integrated in this study, some sections do reflect the German experience. For example, the German Renewable Energy Sources Act (EEG, see page 78) enables also a specific promotion and growth of the geothermal sector in Germany by guaranteeing special feed‐in tariffs for a 20‐years period. During the last years, several countries worldwide have introduced similar renewable energy promotion policies (some of them restricted to certain energy sources only or requiring a certain renewable energy quote), supporting investigations also in geothermal applications. Thus, the experiences in Germany may be of some value. Dependent on the political‐economical framework, the geothermal exploration and exploitation of deeper reservoirs represents an excellent option to extend geothermal applications also in areas where shallow geothermal reservoirs may not be able to match the local energy demand. Therefore, also challenges related to the exploration and exploitation of deep low‐permeability reservoirs are included in this study.

Description: This Scientific Technical Report presents two so-called “Reference reports” produced during the MATRIX project. These reports were provided to the European Commission asdeliverables, namely D8.4 “MATRIX Results I and Reference Report” and D8.5 “MATRIX Results II and Reference Report”. D8.4 presented a series of specific reports outlining theresults of the project, written in a manner accessible not only to the specialist but with a broader audience in mind. D8.5 deals with the risk governance within a multi-hazard and risk context and has since been published. We therefore divide with document in two, where part1 represented the outcomes presented in D8.4 while D8.5 forms part 2.

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: Against the background of EnMAP preparation analyses have been carried out on the status of research in various areas of hyperspectral remote sensing for the use of existing algorithms in the EnMAP application box. The aim was to compose the status of research in Germany and internationally. Therefore, in various fields of expertise applied and accordingly available algorithms and products based on hyperspectral data has been evaluated and documented. The intention has been to demonstrate and to evaluate the added value of hyperspectral remote sensing to multispectral methods for each product. For this purpose analyses have been carried out by different research groups which were based on the specialty and the experience of each group. Hereby a summary was created of each major application perspective and the relevant remote sensing derived variables and significant processing algorithms (state-of-the-art) belonging to this context. Based on this, the research delivers, as a result, a recommendation which of the algorithms should be implemented into the Applikationsbox of EnMAP. Tests of the algorithms or their implementation were not part of the analyses. However, notes have been given on what algorithms should be tested in the context of a detailed preparation phase. An assessment to the further R & D requirements in the development of algorithms has been made on this basis.

Description: The present study investigates the effects of fluid-rock interactions on permeability and the related transport property electrical conductivity of rocks in the context of geothermal energy production from deep sedimentary reservoirs that exist, e.g., in the North German Basin.

Description: [...] In order to construct the 3D structural model of the Norwegian continental margin, all mentioned datasets were compiled and gridded separately for each layer. The gridded data were merged into the 3D structural model and, therefore, all obtained thickness maps and structural depth maps are spatially consistent in 3D.

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: An integrated geological and geophysical approach was applied to comprehend the tectonic setting and seismic structure of the North Tapanuli district (North Sumatra Indonesia) where several geothermal manifestations are located. For the first time, passive seismic methods are used as a geothermal exploration tool in Indonesia. The specific aims of the seismological study are to provide Vp, Vp/Vs, and seismic attenuation images as well as the detailed fault structure of the region derived from seismicity and focal mechanism analysis. A seismic network of 42 short period instruments was installed in the region covering the Tarutung (in the north) and the Sarulla basin (in the south) for 10 months starting from May 2011. The seismic arrivals were detected by using an optimized automatic earthquake detection approach. The earthquakes were then localized by using HYPO71 with a 1D velocity model. In order to increase the picking accuracy, the seismic onsets were revised manually and the earthquakes were relocated by using the same procedure.

Description: This report continues a series of Scientific Technical Reports, in which the theoretical description of the electromagnetic (EM, see Hagedoorn & Greiner-Mai, 2008), topographic (TOP, see Greiner-Mai & Hagedoorn, 2008) and gravitational (GRAV, see Hagedoorn et al., 2012) core-mantle coupling torques are presented in detail. Based on these theoretical descriptions numerical codes were developed to compute individual coupling torques.

Description: In this thesis I focus on the North Alpine pro‐wedge and scrutinize the potential driving forces of tectonic activity. The key questions I try to answer are: - Is it possible to constrain further the timing and amount of deformation (i.e. shortening) in the foreland fold and thrust belt of the European Alps, in particular in Late Neogene times? - What does this timing and magnitude of deformation tell us about the kinematics of late stage exhumation and the relation between the Alps and their foreland? - Can we evaluate the influence of climate (or climate changes) on timing and magnitude of deformation within the foreland fold and thrust belt? To address these questions, I combine low temperature thermochronology (in particular apatite fission track and apatite (U‐Th‐Sm)/He dating) with critical taper analysis and try to extrapolate the present day kinematic situation into the past; thus providing an instrument to understand wedge dynamics through time.

Description: This thesis is organized as a “cumulative thesis” and consists of a series of six chapters (without references and appendix). Chapters 2-5 consist of four individual manuscripts to be published in international peer-reviewed scientific journals. Two manuscripts (chapters 3 and 4) have been already accepted while the other two manuscripts (chapters 2 and 5) have been either submitted or are supposed to be submitted. An outline of each chapter and the contributions of the individual coauthors are provided below. The structure of the thesis (chapter 2-5) is arranged in terms of sample resolution. Chapter 2 focuses on data in monthly resolution via a monthly cleared sediment trap. Chapter 3 is based on annual resolutions, while chapter 4 and 5 discuss data at decadal resolution. Presenting data on different time scales improves the integration of seasonal information in data at millennial time scale and, thus the understanding of seasonal climatic related questions such as seasonality extremes.

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: It is of high interest to know the magnetic field, measured at the earth surface or by satellites, in the earth deep interior, especially at the core-mantle boundary (CMB). This knowledge is of relevance for the determination of fluid motions at the top of the outer core, the estimation of diffusion and the geomagnetic spectrum, as well as in calculations of the electromagnetic core-mantle coupling torques or in studying the behaviour of geomagnetic jerk components near the CMB. The presented procedure of nonharmonic downward continuation (NHDC) is a strong theoretical method, an illposed inverse initial boundary value problem, which determines the given outer geomagnetic field or the secular variation in the deep earth interior. It accounts for a prescribed mantle conductivity model depending on the radius. Boundary values are given only on one, the upper (outer) side of the radial interval. We discuss the theoretical background of the method, referring to the intensively investigated inverse heat conduction problem in the field of parabolic differential equations, and adapt it to the geomagnetic downward continuation problem. Some historical remarks on the early trials in developing this method around the year 1980 are outlined. After investigating the limited possibilities for analytical solutions, we present the numerical algorithm, which uses the integral equation approach, combined with a special regularization variant. It can be implemented on the basis of finite differences or the finite-element technique. This algorithm enables simulations setting up simple function types (e.g. oscillations, time polynomials). In addition, approximative approaches help to reveal the analytical dependence of the solution on the conductivity function, e.g. its impact on the phase shifts or time shifts, which are different for radial and tangential magnetic field components. A couple of new applications are addressed, e.g. to check the divergence condition for the magnetic field at the CMB and the way to make diffusion studies near the CMB. On the basis of NHDC, we derive a new formula for the geomagnetic spectrum at the CMB, which shows in its approximated form the influence of the mantle conductivity model. Finally, some remarks on future possibilities in the field of geomagnetic downward continuation are added.

Description: Film 6: "Scientific Drilling at the pilot site Ketzin" (Length 08:53) "At the pilot site Ketzin three wells were drilled to depths of 750 to 810 meters in 2007 before the start of CO2 injection ..." In 2011 a fourth, and 2012, the fifth well was constructed. This last well (Ktzi 203) for the first time offers the unique opportunity to gain samples (cores) from a storage reservoir that have been exposed to CO2 for more than four years. How were these samples (cores) gained and studied? Production Year: 2012

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: In my thesis, I studied marine and lacustrine sediment cores from different depositional provinces along the south-central Chilean margin with the overall objective to identify their records of paleoclimate and paleotectonics. First of all, I investigated sedimentary sequences that were recovered within the margin-parallel trench system (cp. Figure 1.2) and hence constitute long-term recorders [...] of the sediment transport between the continent and the abyssal zone of the lower plate.

Description: The history of the study of Polar Motion began with the derivation of the equations for the rotation of a rigid body by Euler published in 1758. This was followed by further theoretical contributions made by Lagrange (1788) and Poinsot (1834). To confirm the existence of the polar motion of the Earth in terms of a variation of latitude, intensive efforts were undertaken at several observatories toward the end of the 19th century. During the 7th General Conference of the European Arc Measurement in Rome in October 1883, Fergola had already suggested to investigate the problem. The latitude variation was detected by K¨ustner at the Berlin Observatory in 1888. Following this, during the Annual Conference of the Permanent Commission of the ”Internationale Erdmessung” in Salzburg in September 1888, Foerster proposed to consider the variation of latitude more systematically by a Special Commission. Activities began quickly, and after considerable effort the International Latitude Service (ILS) started in September 1899. The paper reviews, in which way the Geodetic Institute Potsdam contributed to the foundation of the ILS and took part in its activities through the work of Helmert, Albrecht,Wanach and Mahnkopf. Based on international scientific cooperation, the results were the rectangular coordinates of the Polar Motion from 1890.0 to 1922.7 at 0.1 year intervals, in particular those derived from the latitude observations at independent stations from 1890.0 to 1899.8, and those derived from the latitude observations at the ILS stations from 1899.9 to 1922.7

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: 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: 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: Megacities as challenge for interdisciplinary research: the "Risk Habitat Megacity" research initiative / Dirk Heinrichs, Kerstin Krellenberg. - Mega-urban societies at risk / Frauke Kraas, Carsten Butsch. - Megacity Istanbul: earthquake risk and early warning in a megacity / Stefano Parolai, Jochen Zschau, Claus Milkereit, Matteo Picozzi, Angelo Strollo. - Neapel in der Zange / Thomas Walter

Description: The goal of this thesis is to close these gaps (exclude aliasing effect, improve the sensitivity towards short period waves and increase the resolution of the results) and prove, that the RO technique is a powerful tool to derive high resolution global results of absolute momentum flux.

Description: The theme of this thesis is to investigate the sensitivity of several different formations of future satellite gravity missions. The work has three main aspects. The first, and the most important, is the development and testing of a global directional wavelet transformation as a mathematical tool to analyse sensitivity of satellite gravity mission. This is done by propagating full covariance matrices w.r.t. the spherical harmonics functions onto the directional wavelet transform. For the first time, we are able to accurately quantify the stripes that are typical for the error pattern of the GRACE gravity mission. The second aspect is the simulation of a satellite gravity formation, in order to achieve accuracy information in the form of a full covariance matrix. The third aspect involves analyzing results from the GRACE mission, which is already in orbit and has been delivering data since 2002. We compare the simulations of GRACE to the data delivered by the GRACE mission. This way, we are able to establish a relationship between the simulations and real-life data and evaluate the quality of the simulations.

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: [...] A new aspect in this study is the influence of wind-driven waves, sea-ice and icebergs on long-term observation of the Arctic Ocean. An altimetric method is developed, that is applied reliably under these influences. [...]

Description: This volume contains 30 short papers which summarise the main subjects of talks and posters presented at the seventh TRACE (Tree Rings in Archaeology, Climatology and Ecology) conference organized by Ireneusz Malik, Ryszard J. Kaczka and Piotr Owczarek and held in Zakopane, Poland on April 27th - 30th, 2008.

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: 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.