@phdthesis{Lilienkamp2024,
  author    = {Lilienkamp, Henning},
  title     = {Enhanced computational approaches for data-driven characterization of earthquake ground motion and rapid earthquake impact assessment},
  doi       = {10.25932/publishup-63195},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-631954},
  school      = {Universit{\"a}t Potsdam},
  pages     = {x, 145},
  year      = {2024},
  abstract  = {Rapidly growing seismic and macroseismic databases and simplified access to advanced machine learning methods have in recent years opened up vast opportunities to address challenges in engineering and strong motion seismology from novel, datacentric perspectives. In this thesis, I explore the opportunities of such perspectives for the tasks of ground motion modeling and rapid earthquake impact assessment, tasks with major implications for long-term earthquake disaster mitigation. In my first study, I utilize the rich strong motion database from the Kanto basin, Japan, and apply the U-Net artificial neural network architecture to develop a deep learning based ground motion model. The operational prototype provides statistical estimates of expected ground shaking, given descriptions of a specific earthquake source, wave propagation paths, and geophysical site conditions. The U-Net interprets ground motion data in its spatial context, potentially taking into account, for example, the geological properties in the vicinity of observation sites. Predictions of ground motion intensity are thereby calibrated to individual observation sites and earthquake locations. The second study addresses the explicit incorporation of rupture forward directivity into ground motion modeling. Incorporation of this phenomenon, causing strong, pulse like ground shaking in the vicinity of earthquake sources, is usually associated with an intolerable increase in computational demand during probabilistic seismic hazard analysis (PSHA) calculations. I suggest an approach in which I utilize an artificial neural network to efficiently approximate the average, directivity-related adjustment to ground motion predictions for earthquake ruptures from the 2022 New Zealand National Seismic Hazard Model. The practical implementation in an actual PSHA calculation demonstrates the efficiency and operational readiness of my model. In a follow-up study, I present a proof of concept for an alternative strategy in which I target the generalizing applicability to ruptures other than those from the New Zealand National Seismic Hazard Model. In the third study, I address the usability of pseudo-intensity reports obtained from macroseismic observations by non-expert citizens for rapid impact assessment. I demonstrate that the statistical properties of pseudo-intensity collections describing the intensity of shaking are correlated with the societal impact of earthquakes. In a second step, I develop a probabilistic model that, within minutes of an event, quantifies the probability of an earthquake to cause considerable societal impact. Under certain conditions, such a quick and preliminary method might be useful to support decision makers in their efforts to organize auxiliary measures for earthquake disaster response while results from more elaborate impact assessment frameworks are not yet available. The application of machine learning methods to datasets that only partially reveal characteristics of Big Data, qualify the majority of results obtained in this thesis as explorative insights rather than ready-to-use solutions to real world problems. The practical usefulness of this work will be better assessed in the future by applying the approaches developed to growing and increasingly complex data sets.},
  language  = {en}
}
@phdthesis{Koyan2024,
  author    = {Koyan, Philipp},
  title     = {3D attribute analysis and classification to interpret ground-penetrating radar (GPR) data collected across sedimentary environments: Synthetic studies and field examples},
  doi       = {10.25932/publishup-63948},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-639488},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xi, 115, A51},
  year      = {2024},
  abstract  = {Die Untersuchung des oberfl{\"a}chennahen Untergrundes erfolgt heutzutage bei Frage- stellungen aus den Bereichen des Bauwesens, der Arch{\"a}ologie oder der Geologie und Hydrologie oft mittels zerst{\"o}rungsfreier beziehungsweise zerst{\"o}rungsarmer Methoden der angewandten Geophysik. Ein Bereich, der eine immer zentralere Rolle in Forschung und Ingenieurwesen einnimmt, ist die Untersuchung von sediment{\"a}ren Umgebungen, zum Beispiel zur Charakterisierung oberfl{\"a}chennaher Grundwassersysteme. Ein in diesem Kontext h{\"a}ufig eingesetztes Verfahren ist das des Georadars (oftmals GPR - aus dem Englischen ground-penetrating radar). Dabei werden kurze elektromagnetische Impulse von einer Antenne in den Untergrund ausgesendet, welche dort wiederum an Kontrasten der elektromagnetischen Eigenschaften (wie zum Beispiel an der Grundwasseroberfl{\"a}che) reflektiert, gebrochen oder gestreut werden. Eine Empfangsantenne zeichnet diese Signale in Form derer Amplituden und Laufzeiten auf. Eine Analyse dieser aufgezeichneten Signale erm{\"o}glicht Aussagen {\"u}ber den Untergrund, beispielsweise {\"u}ber die Tiefenlage der Grundwasseroberfl{\"a}che oder die Lagerung und Charakteristika oberfl{\"a}chennaher Sedimentschichten. Dank des hohen Aufl{\"o}sungsverm{\"o}gens der GPR-Methode sowie stetiger technologischer Entwicklungen erfolgt heutzutage die Aufzeichnung von GPR- Daten immer h{\"a}ufiger in 3D. Trotz des hohen zeitlichen und technischen Aufwandes f{\"u}r die Datenakquisition und -bearbeitung werden die resultierenden 3D-Datens{\"a}tze, welche den Untergrund hochaufl{\"o}send abbilden, typischerweise von Hand interpretiert. Dies ist in der Regel ein {\"a}ußerst zeitaufwendiger Analyseschritt. Daher werden oft repr{\"a}sentative 2D-Schnitte aus dem 3D-Datensatz gew{\"a}hlt, in denen markante Reflektionsstrukuren markiert werden. Aus diesen Strukturen werden dann sich {\"a}hnelnde Bereiche im Untergrund als so genannte Radar-Fazies zusammengefasst. Die anhand von 2D-Schnitten erlangten Resultate werden dann als repr{\"a}sentativ f{\"u}r die gesamte untersuchte Fl{\"a}che angesehen. In dieser Form durchgef{\"u}hrte Interpretationen sind folglich oft unvollst{\"a}ndig sowie zudem in hohem Maße von der Expertise der Interpretierenden abh{\"a}ngig und daher in der Regel nicht reproduzierbar. Eine vielversprechende Alternative beziehungsweise Erg{\"a}nzung zur manuellen In- terpretation ist die Verwendung von so genannten GPR-Attributen. Dabei werden nicht die aufgezeichneten Daten selbst, sondern daraus abgeleitete Gr{\"o}ßen, welche die markanten Reflexionsstrukturen in 3D charakterisieren, zur Interpretation herangezogen. In dieser Arbeit wird anhand verschiedener Feld- und Modelldatens{\"a}tze untersucht, welche Attribute sich daf{\"u}r insbesondere eignen. Zudem zeigt diese Arbeit, wie ausgew{\"a}hlte Attribute mittels spezieller Bearbeitungs- und Klassifizierungsmethoden zur Erstellung von 3D-Faziesmodellen genutzt werden k{\"o}nnen. Dank der M{\"o}glichkeit der Erstellung so genannter attributbasierter 3D-GPR-Faziesmodelle k{\"o}nnen zuk{\"u}nftige Interpretationen zu gewissen Teilen automatisiert und somit effizienter durchgef{\"u}hrt werden. Weiterhin beschreiben die so erhaltenen Resultate den untersuchten Untergrund in reproduzierbarer Art und Weise sowie umf{\"a}nglicher als es bisher mittels manueller Interpretationsmethoden typischerweise m{\"o}glich war.},
  language  = {en}
}
@phdthesis{Rasche2024,
  author    = {Rasche, Daniel},
  title     = {Cosmic-ray neutron sensing for the estimation of soil moisture},
  doi       = {10.25932/publishup-63646},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-636465},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvi, 194},
  year      = {2024},
  abstract  = {Water stored in the unsaturated soil as soil moisture is a key component of the hydrological cycle influencing numerous hydrological processes including hydrometeorological extremes. Soil moisture influences flood generation processes and during droughts when precipitation is absent, it provides plant with transpirable water, thereby sustaining plant growth and survival in agriculture and natural ecosystems. Soil moisture stored in deeper soil layers e.g. below 100 cm is of particular importance for providing plant transpirable water during dry periods. Not being directly connected to the atmosphere and located outside soil layers with the highest root densities, water in these layers is less susceptible to be rapidly evaporated and transpired. Instead, it provides longer-term soil water storage increasing the drought tolerance of plants and ecosystems. Given the importance of soil moisture in the context of hydro-meteorological extremes in a warming climate, its monitoring is part of official national adaption strategies to a changing climate. Yet, soil moisture is highly variable in time and space which challenges its monitoring on spatio-temporal scales relevant for flood and drought risk modelling and forecasting. Introduced over a decade ago, Cosmic-Ray Neutron Sensing (CRNS) is a noninvasive geophysical method that allows for the estimation of soil moisture at relevant spatio-temporal scales of several hectares at a high, subdaily temporal resolution. CRNS relies on the detection of secondary neutrons above the soil surface which are produced from high-energy cosmic-ray particles in the atmosphere and the ground. Neutrons in a specific epithermal energy range are sensitive to the amount of hydrogen present in the surroundings of the CRNS neutron detector. Due to same mass as the hydrogen nucleus, neutrons lose kinetic energy upon collision and are subsequently absorbed when reaching low, thermal energies. A higher amount of hydrogen therefore leads to fewer neutrons being detected per unit time. Assuming that the largest amount of hydrogen is stored in most terrestrial ecosystems as soil moisture, changes of soil moisture can be estimated through an inverse relationship with observed neutron intensities. Although important scientific advancements have been made to improve the methodological framework of CRNS, several open challenges remain, of which some are addressed in the scope of this thesis. These include the influence of atmospheric variables such as air pressure and absolute air humidity, as well as, the impact of variations in incoming primary cosmic-ray intensity on observed epithermal and thermal neutron signals and their correction. Recently introduced advanced neutron-to-soil moisture transfer functions are expected to improve CRNS-derived soil moisture estimates, but potential improvements need to be investigated at study sites with differing environmental conditions. Sites with strongly heterogeneous, patchy soil moisture distributions challenge existing transfer functions and further research is required to assess the impact of, and correction of derived soil moisture estimates under heterogeneous site conditions. Despite its capability of measuring representative averages of soil moisture at the field scale, CRNS lacks an integration depth below the first few decimetres of the soil. Given the importance of soil moisture also in deeper soil layers, increasing the observational window of CRNS through modelling approaches or in situ measurements is of high importance for hydrological monitoring applications. By addressing these challenges, this thesis aids to closing knowledge gaps and finding answers to some of the open questions in CRNS research. Influences of different environmental variables are quantified, correction approaches are being tested and developed. Neutron-to-soil moisture transfer functions are evaluated and approaches to reduce effects of heterogeneous soil moisture distributions are presented. Lastly, soil moisture estimates from larger soil depths are derived from CRNS through modified, simple modelling approaches and in situ estimates by using CRNS as a downhole technique. Thereby, this thesis does not only illustrate the potential of new, yet undiscovered applications of CRNS in future but also opens a new field of CRNS research. Consequently, this thesis advances the methodological framework of CRNS for above-ground and downhole applications. Although the necessity of further research in order to fully exploit the potential of CRNS needs to be emphasised, this thesis contributes to current hydrological research and not least to advancing hydrological monitoring approaches being of utmost importance in context of intensifying hydro-meteorological extremes in a changing climate.},
  language  = {en}
}
@phdthesis{Illien2023,
  author    = {Illien, Luc},
  title     = {Time-dependent properties of the shallow subsurface},
  doi       = {10.25932/publishup-59936},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-599367},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xviii, 133},
  year      = {2023},
  abstract  = {The shallow Earth's layers are at the interplay of many physical processes: some being driven by atmospheric forcing (precipitation, temperature...) whereas others take their origins at depth, for instance ground shaking due to seismic activity. These forcings cause the subsurface to continuously change its mechanical properties, therefore modulating the strength of the surface geomaterials and hydrological fluxes. Because our societies settle and rely on the layers hosting these time-dependent properties, constraining the hydro-mechanical dynamics of the shallow subsurface is crucial for our future geographical development. One way to investigate the ever-changing physical changes occurring under our feet is through the inference of seismic velocity changes from ambient noise, a technique called seismic interferometry. In this dissertation, I use this method to monitor the evolution of groundwater storage and damage induced by earthquakes. Two research lines are investigated that comprise the key controls of groundwater recharge in steep landscapes and the predictability and duration of the transient physical properties due to earthquake ground shaking. These two types of dynamics modulate each other and influence the velocity changes in ways that are challenging to disentangle. A part of my doctoral research also addresses this interaction. Seismic data from a range of field settings spanning several climatic conditions (wet to arid climate) in various seismic-prone areas are considered. I constrain the obtained seismic velocity time-series using simple physical models, independent dataset, geophysical tools and nonlinear analysis. Additionally, a methodological development is proposed to improve the time-resolution of passive seismic monitoring.},
  language  = {en}
}
@phdthesis{Liu2020,
  author    = {Liu, Sibiao},
  title     = {Controls of foreland-deformation patterns in the orogen-foreland shortening system},
  doi       = {10.25932/publishup-44573},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-445730},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vi, 150},
  year      = {2020},
  abstract  = {The Andean Plateau (Altiplano-Puna Plateau) of the southern Central Andes is the second-highest orogenic plateau on our planet after Tibet. The Andean Plateau and its foreland exhibit a pronounced segmentation from north to south regarding the style and magnitude of deformation. In the Altiplano (northern segment), more than 300 km of tectonic shortening has been recorded, which started during the Eocene. A well-developed thin-skinned thrust wedge located at the eastern flank of the plateau (Subandes) indicates a simple-shear shortening mode. In contrast, the Puna (southern segment) records approximately half of the shortening of the Altiplano - and the shortening started later. The tectonic style in the Puna foreland switches to a thick-skinned mode, which is related to pure-shear shortening. In this study, carried out in the framework of the StRATEGy project, high-resolution 2D thermomechanical models were developed to systematically investigate controls of deformation patterns in the orogen-foreland pair. The 2D and 3D models were subsequently applied to study the evolution of foreland deformation and surface topography in the Altiplano-Puna Plateau. The models demonstrate that three principal factors control the foreland-deformation patterns: (i) strength differences in the upper lithosphere between the orogen and its foreland, rather than a strength difference in the entire lithosphere; (ii) gravitational potential energy of the orogen (GPE) controlled by crustal and lithospheric thicknesses, and (iii) the strength and thickness of foreland-basin sediments. The high-resolution 2D models are constrained by observations and successfully reproduce deformation structures and surface topography of different segments of the Altiplano-Puna plateau and its foreland. The developed 3D models confirm these results and suggest that a relatively high shortening rate in the Altiplano foreland (Subandean foreland fold-and-thrust belt) is due to simple-shear shortening facilitated by thick and mechanically weak sediments, a process which requires a much lower driving force than the pure-shear shortening deformation mode in the adjacent broken foreland of the Puna, where these thick sedimentary basin fills are absent. Lower shortening rate in the Puna foreland is likely accommodated in the forearc by the slab retreat.},
  language  = {en}
}
@phdthesis{Zeckra2020,
  author    = {Zeckra, Martin},
  title     = {Seismological and seismotectonic analysis of the northwestern Argentine Central Andean foreland},
  doi       = {10.25932/publishup-47324},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-473240},
  school      = {Universit{\"a}t Potsdam},
  pages     = {vii, 120},
  year      = {2020},
  abstract  = {After a severe M W 5.7 earthquake on October 17, 2015 in El Galp{\´o}n in the province of Salta NW Argentina, I installed a local seismological network around the estimated epicenter. The network covered an area characterized by inherited Cretaceous normal faults and neotectonic faults with unknown recurrence intervals, some of which may have been reactivated normal faults. The 13 three-component seismic stations recorded data continuously for 15 months. The 2015 earthquake took place in the Santa B{\´a}rbara System of the Andean foreland, at about 17km depth. This region is the easternmost morphostructural region of the central Andes. As a part of the broken foreland, it is bounded to the north by the Subandes fold-and-thrust belt and the Sierras Pampeanas to the south; to the east lies the Chaco-Paran{\´a} basin. A multi-stage morphotectonic evolution with thick-skinned basement uplift and coeval thin-skinned deformation in the intermontane basins is suggested for the study area. The release of stresses associated with the foreland deformation can result in strong earthquakes, as the study area is known for recurrent and historical, destructive earthquakes. The available continuous record reaches back in time, when the strongest event in 1692 (magnitude 7 or intensity IX) destroyed the city of Esteco. Destructive earthquakes and surface deformation are thus a hallmark of this part of the Andean foreland. With state-of-the-art Python packages (e.g. pyrocko, ObsPy), a semi-automatic approach is followed to analyze the collected continuous data of the seismological network. The resulting 1435 hypocenter locations consist of three different groups: 1.) local crustal earthquakes (nearly half of the events belong to this group), 2.) interplate activity, of regional distance in the slab of the Nazca-plate, and 3.) very deep earthquakes at about 600km depth. My major interest focused on the first event class. Those crustal events are partly aftershock events of the El Galp{\´o}n earthquake and a second earthquake, in the south of the same fault. Further events can be considered as background seismicity of other faults within the study area. Strikingly, the seismogenic zone encompass the whole crust and propagates brittle deformation down, close to the Moho. From the collected seismological data, a local seismic velocity model is estimated, using VELEST. After the execution of various stability tests, the robust minimum 1D-velocity model implies guiding values for the composition of the local, subsurface structure of the crust. Afterwards, performing a hypocenter relocation enables the assignment of individual earthquakes to aftershock clusters or extended seismotectonic structures. This allows the mapping of previously unknown seismogenic faults. Finally, focal mechanisms are modeled for events with acurately located hypocenters, using the newly derived local velocity model. A compressive regime is attested by the majority of focal mechanisms, while the strike direction of the individual seismogenic structures is in agreement with the overall north - south orientation of the Central Andes, its mountain front, and individual mountain ranges in the southern Santa-B{\´a}rbara-System.},
  language  = {en}
}
@masterthesis{Lehmann2017,
  type      = {Bachelor Thesis},
  author    = {Lehmann, Lukas},
  title     = {Performance Test von Phasenpickern},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-401993},
  school      = {Universit{\"a}t Potsdam},
  pages     = {I, 40, XXXIX},
  year      = {2017},
  abstract  = {Die genauen Einsatzzeiten seismischer P-Phasen von Erdbeben werden in SeisComP3 und anderen Auswerteprogrammen standardm{\"a}ßig und in Echtzeit automatisch bestimmt. S-Phasen stellen dagegen eine weit gr{\"o}ßere Herausforderung dar. Nur mit genauen Picks der P- bzw. S-Phasen k{\"o}nnen die Erdbebenlokationen korrekt und stabil bestimmt werden. Darum besteht erhebliches Interesse, diese mit hoher Genauigkeit zu bestimmen. Das Ziel der vorliegenden Bachelorarbeit war es, vier verschiedene, bereits vorhandene S-Phasenpicker auf ausgew{\"a}hlte Parameter optimal zu konfigurieren, auf Testdaten anzuwenden und deren Leistungsf{\"a}higkeit objektiv zu bewerten. Dazu wurden ein S-Picker (S-L2) aus dem OpenSource SeisComp3-Programmpaket, zwei S-Picker (S-AIC, S-AIC-V) als kommerzielles Modul der Firma gempa GmbH f{\"u}r SeisComP3 und ein S-Picker (Frequenzband) aus dem OpenSource PhasePaPy-Paket ausgew{\"a}hlt. Die Bewertung erfolgte durch Vergleich automatischer Picks mit manuell bestimmten Einsatzzeiten. Alle vier Picker wurden separat konfiguriert und auf drei verschiedene Datens{\"a}tze von Erdbeben in N-Chile und im Vogtland, Deutschland, angewandt. Dazu wurden regional bzw. lokal typische Erdbeben zuf{\"a}llig ausgew{\"a}hlt und die P- und S-Phasen manuell bestimmt. Mit den zu testenden S-Pickeralgorithmen wurden dieselben Daten durchsucht und die Picks automatisch bestimmt. Die Konfigurationen der Picker wurden gleichzeitig automatisch und objektiv durch iterative Anpassung optimiert. Ein neu erstelltes Bewertungssystem vergleicht die manuellen und die automatisch gefundenen S-Picks anhand von definierten Qualit{\"a}tsfaktoren. Die Qualit{\"a}tsfaktoren sind: der Mittelwert und die Standardabweichung der zeitlichen Differenzen zwischen den S-Picks, die Anzahl an {\"u}bereinstimmenden S-Picks, die Prozentangaben {\"u}ber m{\"o}gliche S-Picks und die ben{\"o}tigt Rechenzeit. Die objektive Bewertung erfolgte anhand eines Scores. Der Scorewert ergibt sich aus der gewichteten Summe folgender normierter Qualit{\"a}tsfaktoren: Standardabweichung (20\%), Mittelwert (20\%) und Prozentangabe {\"u}ber m{\"o}gliche S-Picks (60\%). Konfigurationen mit hohem Score werden bevorzugt. Die bevorzugten Konfigurationen der verschiedenen Picker wurden miteinander verglichen, um den am besten geeigneten S-Pickeralgorithmus zu bestimmen. Allgemein zeigt sich, dass der S-AIC Picker f{\"u}r jeden der drei Datens{\"a}tze die h{\"o}chsten Scores und damit die besten Ergebnisse liefert. Dabei wurde f{\"u}r jeden Datensatz ein andere Konfiguration der Parameter des S-AIC Pickers als die am besten geeignete bezeichnet. Daher ist f{\"u}r jede Erdbebenregion eine andere Konfigurationen erforderlich, um optimale Ergebnisse mit diesem S-Picker zu bekommen.},
  language  = {de}
}
@phdthesis{Priegnitz2015,
  author    = {Priegnitz, Mike},
  title     = {Development of geophysical methods to characterize methane hydrate reservoirs on a laboratory scale},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-89321},
  school      = {Universit{\"a}t Potsdam},
  pages     = {X, 99},
  year      = {2015},
  abstract  = {Gashydrate sind kristalline Feststoffe bestehend aus Wasser und Gasmolek{\"u}len. Sie sind stabil bei erh{\"o}hten Dr{\"u}cken und niedrigen Temperaturen. Nat{\"u}rliche Hydratvorkommen treten daher an Kontinentalh{\"a}ngen, in Permafrostb{\"o}den und in tiefen Seen sowie Binnenmeeren auf. Bei der Hydratbildung orientieren sich die Wassermolek{\"u}le neu und bilden sogenannte K{\"a}figstrukturen, in die Gas eingelagert werden kann. Aufgrund des hohen Drucks bei der Hydratbildung k{\"o}nnen große Mengen an Gas in die Hydratstruktur eingebaut werden. Das Volumenverh{\"a}ltnis von Wasser zu Gas kann dabei bis zu 1:172 bei 0°C und Atmosph{\"a}rendruck betragen. Nat{\"u}rliche Gashydrate enthalten haupts{\"a}chlich Methan. Da Methan sowohl ein Treibhausgas als auch ein Brenngas ist, stellen Gashydrate gleichermaßen eine potentielle Energieressource sowie eine m{\"o}gliche Quelle f{\"u}r Treibhausgase dar. Diese Arbeit untersucht die physikalischen Eigenschaften von Methanhydrat ges{\"a}ttigten Sedimentproben im Labormaßstab. Dazu wurde ein großer Reservoirsimulator (LARS) mit einer eigens entwickelten elektrischen Widerstandstomographie ausger{\"u}stet, die das erste Mal an hydratges{\"a}ttigten Sedimentproben unter kontrollierten Temperatur-, Druck-, und Hydrats{\"a}ttigungsbedingungen im Labormaßstab angewendet wurde. {\"U}blicherweise ist der Porenraum von (marinen) Sedimenten mit elektrisch gut leitendem Salzwasser gef{\"u}llt. Da Hydrate einen elektrischen Isolator darstellen, ergeben sich große Kontraste hinsichtlich der elektrischen Eigenschaften im Porenraum w{\"a}hrend der Hydratbildung und -zersetzung. Durch wiederholte Messungen w{\"a}hrend der Hydraterzeugung ist es m{\"o}glich die r{\"a}umliche Widerstandsverteilung in LARS aufzuzeichnen. Diese Daten bilden in der Folge die Grundlage f{\"u}r eine neue Auswerteroutine, welche die r{\"a}umliche Widerstandsverteilung in die r{\"a}umliche Verteilung der Hydrats{\"a}ttigung {\"u}berf{\"u}hrt. Dadurch ist es m{\"o}glich, die sich {\"a}ndernde Hydrats{\"a}ttigung sowohl r{\"a}umlich als auch zeitlich hoch aufgel{\"o}st w{\"a}hrend der gesamten Hydraterzeugungsphase zu verfolgen. Diese Arbeit zeigt, dass die entwickelte Widerstandstomographie eine gute Datenqualit{\"a}t aufwies und selbst geringe Hydrats{\"a}ttigungen innerhalb der Sedimentprobe detektiert werden konnten. Bei der Umrechnung der Widerstandsverteilung in lokale Hydrat-S{\"a}ttigungswerte wurden die besten Ergebnisse mit dem Archie-var-phi Ansatz erzielt, der die zunehmende Hydratphase dem Sedimentger{\"u}st zuschreibt, was einer Abnahme der Porosit{\"a}t gleichkommt. Die Widerstandsmessungen zeigten weiterhin, dass die schnelle Hydraterzeugung im Labor zur Ausbildung von kleinen Hydratkristallen f{\"u}hrte, die dazu neigten, zu rekristalliesieren. Es wurden weiterhin Hydrat-Abbauversuche durchgef{\"u}hrt, bei denen die Hydratphase {\"u}ber Druckerniedrigung in Anlehnung an den 2007/2008 Mallik Feldtest zersetzt wurde. Dabei konnte beobachtet werden, dass die Muster der Gas- undWasserflussraten im Labor zum Teil gut nachgebildet werden konnten, jedoch auch aufbaubedingte Abweichungen auftraten. In zwei weiteren Langzeitversuchen wurde die Realisierbarkeit und das Verhalten bei CO2-CH4-Hydrat Austauschversuchen in LARS untersucht. Das tomographische Messsystem wurde dabei genutzt um w{\"a}hrend der CH4 Hydrat Aufbauphase die Hydratverteilung innerhalb der Sedimentprobe zu {\"u}berwachen. Im Zuge der anschließenden CO2-Injektion konnte mithilfe der Widerstandstomographie die sich ausbreitende CO2-Front {\"u}berwacht und der Zeitpunkt des CO2 Durchbruchs identifiziert werden.},
  language  = {en}
}
@phdthesis{Liebs2014,
  author    = {Liebs, G{\"o}ran},
  title     = {Ground penetration radar wave velocities and their uncertainties},
  doi       = {10.25932/publishup-43680},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-436807},
  school      = {Universit{\"a}t Potsdam},
  pages     = {ii, 106},
  year      = {2014},
  abstract  = {We develop three new approaches for ground penetration wave velocity calcultaions. The first is based on linear moveout spectra to find the optimum ground wave velocity including uncertainties from multi-offset data gathers. We used synthetic data to illustrate the principles of the method and to investigate uncertainties in ground wave velocity estimates. To demonstrate the applicability of the approach to real data, we analyzed GPR data sets recorded at field sites in Canada over an annual cycle from Steelman \& Endres [2010]. The results obtained by this efficient and largely automated procedure agree well with the manual achieved results of Steelman \& Endres [2010], derived by a more laborious largely manual analysis strategy. Then we develop a second methodology to global invert reflection traveltimes with a particle swarm optimization approach more precise then conventional spectral NMO-based velocity analysis (e.g., Greaves et al. [1996]). For global optimization, we use particle swarm optimization (PSO; Kennedy \& Eberhart [1995]) in the combination with a fast eikonal solver as forward solver (Sethian [1996]; Fomel [1997a]; Sethian \& Popovici [1999]). This methodology allows us to generate reliability CMP derived models of subsurface velocities and water content including uncertainties. We test this method with synthetic data to study the behavior of the PSO algorithm. Afterward, We use this method to analyze our field data from a well constrained test site in Horstwalde, Germany. The achieved velocity models from field data showed good agreement to borehole logging and direct-push data (Schmelzbach et al. [2011]) at the same site position. For the third method we implement a global optimization approach also based on PSO to invert direct-arrival traveltimes of VRP data to obtain high resolution 1D velocity models including quantitative estimates of uncertainty. Our intensive tests with several traveltime data sets helped to understand the behavior of PSO algorithm for inversion. Integration of the velocity model to VRP reflection imaging and attenuation model improved the potential of VRP surveying. Using field data, we examine this novel analysis strategy for the development of petrophysical models and the linking between GPR borehole and other logging data to surface GPR reflection data.},
  language  = {de}
}
@misc{AnischAndressBancareletal.2011,
  author    = {Anisch, Michael and Andress, Reinhard and Bancarel, Gilles and Reich, Karin and Roussanova, Elena and Biermann, Kurt-Reinhard and Schwarz, Ingo},
  title     = {HiN : Alexander von Humboldt im Netz},
  volume    = {XII},
  number    = {22},
  editor    = {Ette, Ottmar and Knobloch, Eberhard},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {1617-5239},
  doi       = {10.18443/hinvol12iss222011},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57503},
  pages     = {91},
  year      = {2011},
  abstract  = {Inhalt: - Michael Anisch: Bloß keine Tiziane! Poker um den Posten des Generaldirektors der Kunstmuseen - Reinhard Andress: Alexander von Humboldt und Carlos Mont{\´u}far als Reisegef{\"a}hrten: ein Vergleich ihrer Tageb{\"u}cher zum Chimborazo-Aufstieg - Gilles Bancarel: L'Histoire des deux Indes ou la d{\´e}couverte de la mondialisation - Karin Reich: Alexander von Humboldt und Carl Friedrich Gauß als Wegbereiter der neuen Disziplin Erdmagnetismus - Elena Roussanova: Russland ist seit jeher das gelobte Land f{\"u}r Magnetismus gewesen: Alexander von Humboldt, Carl Friedrich Gauß und die Erforschung des Erdmagnetismus in Russland -Kurt-R. Biermann/Ingo Schwarz: Gef{\"a}lschter Humboldt (mit einer Einleitung von Ulrich P{\"a}ßler)},
  language  = {mul}
}
@article{Roussanova2011,
  author    = {Roussanova, Elena},
  title     = {Russland ist seit jeher das gelobte Land f{\"u}r Magnetismus gewesen},
  series = {Alexander von Humboldt im Netz ; international review for Humboldtian studies},
  volume    = {xii},
  journal   = {Alexander von Humboldt im Netz ; international review for Humboldtian studies},
  number    = {22},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {2568-3543},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57525},
  pages     = {56 -- 83},
  year      = {2011},
  abstract  = {Wegen seiner riesigen Ausdehnung hat Russland bei der wissenschaftlichen Erforschung des Erdmagnetismus bereits im 18. Jahrhundert und erst recht im 19. Jahrhundert eine herausragende Rolle gespielt. Alexander von Humboldts Engagement auf dem Gebiet des Erdmagnetismus, sein organisatorisches und diplomatisches Geschick verhalfen dazu, dass man sich international und vielerorts dem Ph{\"a}nomen des Erdmagnetismus zuwandte. Carl Friedrich Gauß stellte dessen Erforschung in der relativ kurzen Zeit zwischen 1833 und 1839 auf ein ganz neues wissenschaftliches Fundament. Die Pl{\"a}ne Humboldts, die Erde m{\"o}glichst global physikalisch zu erforschen, und die Pl{\"a}ne von Gauß, die erdmagnetischen Forschungen zentral zu koordinieren, gipfelten 1849 in der Gr{\"u}ndung des Physikalischen Hauptobservatoriums in St. Petersburg, das zu jener Zeit eine absolut neuartige Institution darstellte - es war der Erforschung der neuen Disziplin Geophysik gewidmet. An der Spitze dieser Institution stand der russische Physiker Adolph Theodor Kupffer, Mitarbeiter und Kollege sowohl von Humboldt als auch von Gauß.},
  language  = {de}
}
@article{VitteWittgensteinDiasdeSilveira2010,
  author    = {Vitte, Antonio Carlos and Wittgenstein Dias de Silveira, Roberison},
  title     = {Alexander von Humboldt y la g{\´e}nesis de la geograf{\´i}a f{\´i}sica moderna},
  series = {Alexander von Humboldt im Netz ; international review for Humboldtian studies},
  volume    = {XI},
  journal   = {Alexander von Humboldt im Netz ; international review for Humboldtian studies},
  number    = {21},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {2568-3543},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-51787},
  pages     = {72 -- 85},
  year      = {2010},
  abstract  = {El art{\´i}culo discute la formaci{\´o}n de los conceptos de la naturaleza, espacio y morfolog{\´i}a en la obra de Alexander von Humboldt y sus impactos en la constituci{\´o}n de la geograf{\´i}a f{\´i}sica moderna. Influido por las reflexiones de Kant en la Cr{\´i}tica del Juicio, por los trabajos de Goethe y de Schelling, Humboldt desarrollar{\´a} una nueva interpretaci{\´o}n y representaci{\´o}n de la naturaleza en la superficie terrestre, donde el concepto de espacialidad ser{\´a} fundamental para la explicaci{\´o}n de los fen{\´o}menos de la naturaleza. La geograf{\´i}a f{\´i}sica moderna se estructura a partir de un complejo entrecruzamiento de influencias, tanto est{\´e}ticas como instrumentales trabajadas por Humboldt, donde el principio de la conexi{\´o}n ser{\´a} importante para la invenci{\´o}n art{\´i}stica y cient{\´i}fica del concepto de paisaje geogr{\´a}fico.},
  language  = {es}
}
@misc{SchulzDepetrisEtteetal.2010,
  author    = {Schulz, Carolin and Depetris, Carolina and Ette, Ottmar and Knobloch, Eberhard and Puig-Samper, Miguel {\´A}ngel and Rebok, Sandra and Schifko, Georg and Vitte, Antonio Carlos and Wittgenstein Dias da Silveira, Roberison and Schwarz, Ingo and Werther, Romy and Jahn, Ilse},
  title     = {HiN : Alexander von Humboldt im Netz},
  volume    = {XI},
  number    = {21},
  editor    = {Ette, Ottmar and Knobloch, Eberhard},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {1617-5239},
  doi       = {10.18443/hinvol11iss212010},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49217},
  pages     = {101},
  year      = {2010},
  abstract  = {Inhalt: Carolin Schulz: „Ein scharfsinniger Kopf aus Berlin!" Ein unver{\"o}ffentlichtes Empfehlungsschreiben f{\"u}r Leopold von Buch - Carolina Depetris: El orientalismo como episteme: Fr{\´e}d{\´e}ric de Waldeck y las ruinas mayas - Ottmar Ette: R{\´e}flexions europ{\´e}ennes sur deux phases de mondialisation acc{\´e}l{\´e}r{\´e}e chez Cornelius de Pauw, Georg Forster, Guillaume-Thomas Raynal et Alexandre de Humboldt - Eberhard Knobloch: Nomos und physis - Alexander von Humboldt und die Tradition antiker Denkweisen und Vorstellungen Miguel-{\´A}ngel Puig-Samper, Sandra Rebok: Charles Darwin and Alexander von Humboldt: An exchange of looks between two famous naturalists - Georg Schifko: Jules Vernes literarische Thematisierung der Kanarischen Inseln als Hommage an Alexander v. Humboldt - Antonio Carlos Vitte, Roberison Wittgenstein Dias de Silveira: Alexander von Humboldt y la g{\´e}nesis de la geograf{\´i}a f{\´i}sica moderna - Ingo Schwarz: Eine Alexander-von-Humboldt-Forscherin mit Profil: Ilse Jahn (1922-2010) - Romy Werther, Ingo Schwarz: Ilse Jahn: Schriften zur Alexander-von-Humboldt-Forschung - Eine Auswahlbibliographie - Ilse Jahn: Die anatomischen Studien der Br{\"u}der Humboldt unter Justus Christian Loder in Jena},
  language  = {mul}
}