ALBERT

Description: This report compiles observations made within a time frame of two months on 24 representative thin-section samples representing the periods before and after 4- and 9-years of injection of CO2 into the reservoir. Given this short period of time until completion of this report, some observations and conclusions drawn have to be judged preliminary. Further analytical work and in-depth interpretation of the results are underway. Information provided for the period 0–4 years after CO2 injection include observations made by S. Bock in the framework of her not yet finished Ph.D. thesis.

Description: The FOSA (FOgo Seismic Array) project has been carried out from October 2015 to December 2016 to investigate the seismicity of Fogo volcano after its eruption in 2014/2015. Fogo is the only volcano of the Cape Verde archipelago with reported historic eruptions. The eruptions occur frequently with an interval of about 20 years. However, the structure and extent of the related volcanic plumbing system are not well understood. The focus of the FOSA project was on the detection of ongoing magmatic activity and information about the plumbing system, using seismic array techniques. The array of the FOSA study was operated from October 2015 to December 2016, close to the village Achada Furna. From January 2016 we complemented the network with three additional broadband stations for an improved event detection and localization.

Description: The KISS network was installed in the frame of the “Klyuchevskoy Investigation - Seismic Structure of an extraordinary volcanic system” project and recorded data between summer 2015 and summer 2016 in one of the world’s largest clusters of subduction volcanoes - the Klyuchevskoy volcanic group (KVG). It is located in eastern Russia at the northern end of the Kuril-Kamchatka subduction zone close to its intersection with the Aleutian arc and the north-western termination of Hawaii-Emperor seamount chain. Additional to the 4700m high Mount Klyuchevskoy the KVG contains 12 other volcanoes that have together erupted about 1 cubic meter rock per second averaged over the past 10,000 years. Among those Klyuchevskoy, Bezymianny and Tolbachik were the most active ones during the last decades with eruptions styles ranging from explosive to Hawaiian-type. The KISS experiment is designed to investigate the volcanic and seismic processes and its structural setting in the KVG. The network covers a circular region of about 80km diameter with some linear extensions. It includes data from 77 temporary seismic stations with broadband and short period sensors that were installed on concrete plates in about 60cm deep holes. Due to the local conditions the stations were battery powered and could not be serviced during the experiment. GPS reception of the digitizers was not continuous at all stations due to thick snow cover and vegetation. Waveform data are available from the GEOFON data centre, under network code X9, and are embargoed until end of 2019.

Description: In geosciences the discretization of complex 3D model volumes into finite elements can be a time-consuming task and often needs experience with a professional software. In particular, low angle outcropping or out-pinching geological units, i.e. geological layers that are represented in the model volume, pose serious challenges. Another example are changes in the geometry of a model, which can occur at one point of a project, when re-meshing is not an option anymore or would involve a significant amount of additional time to invest. In order to speed up and automate the process of discretization, Apple PY (Automatic Portioning Preventing Lengthy manual Element assignment for PYthon) separates the process of mesh-generation and unit assignment. It requires an existing mesh together with separate information on the depths of the interfaces between geological units (herein called horizons). These two pieces of information are combined and used to assign the individual elements to different units. The uniform mesh is created with a standard meshing software and has to be available as an Abaqus input file. The information on the horizons depths and lateral variations in the depths is provided in a text file. Apple PY compares the element location and depth with that of the horizons in order to assign each element to a corresponding geological unit below or above a certain horizon. The script files are provided for download at http://github.com/MorZieg/APPLE_PY. Table 0-1 gives an overview of the folder structure and input files with a short explanation.

Description: This report describes the KTB Borehole Measurements Data of the German Continental Deep Drilling Program (Kontinentales Tiefbohrprogramm der Bundesrepublik Deutschland), operated by the GFZ German Research Centre for Geosciences. Extensive borehole measurements were performed during the active drilling phase of the KTB pilot and main hole (1989-1994). This report provides the full description of the logging data. Please read it thoroughly to avoid inappropriate or wrong use of the data. The terms borehole measurements, downhole logging, and logging are used synonymously here. The KTB logging data files contain the final processed versions of the geoscientific borehole logging data from logs in the two KTB boreholes: Boreholes Geographic Coordinates (WGS84) KTB-Oberpfalz VB (KTB Vorbohrung/Pilot Hole or KTB-VB) 49.8153 N, 12.118 E KTB-Oberpfalz HB (KTB Hauptbohrung/Main Hole or KTB-HB) 49.8152 N, 12.1205 E

Description: The 3D geomechanical-numerical modelling of the in-situ stress state aims at a continuous description of the stress state in a subsurface volume. It requires observed stress information within the model volume that are used as a reference. Once the modelled stress state is in agreement with the observed reference stress data the model is assumed to provide the continuous stress state in its entire volume. The modelled stress state is fitted to the reference stress data records by adaptation of the displacement boundary conditions. This process is herein referred to as calibration. Depending on the amount of available stress data records and the complexity of the model the manual calibration is a lengthy process of trial-and-error modelling and analysis until best-fit boundary conditions are found. The Fast Automatic Stress Tensor Calibration (FAST Calibration) is a Python function that facilitates and speeds up this calibration process. By using a linear regression it requires only three model scenarios with different boundary conditions. The stress states from the three model scenarios at the locations of the reference stress data records are extracted. The differences between the modelled and observed stress states are used for a linear regression that allows to compute the displacement boundary conditions required for the best-fit modelled stress state. If more than one reference stress state is provided, the influence of the individual observed stress data records on the best-fit boundary conditions can be weighted. The script files are provided for download at: http://github.com/MorZieg/PyFAST_Calibration

Description: The Earth’s upper atmosphere – a part of it, the ionosphere- is a dynamic partly ionized region with temporal and spatial variations under different phases of solar activity. The ionosphere being a dispersive medium causes signal strength fluctuation, propagation delay, signal attenuation, and signal degradation. These have constituted significant threats to both communication and navigation systems operating in microwave band which is due to the presence of high electron density and its irregularities. The key parameter of the ionosphere which is closely related to most of these delay effects on radio signals is the electron density and density gradients, in particular - its vertical integral, the Total Electron Content (TEC) which can be estimated from the Global Positioning System (GPS) data. The estimated TEC profiles, and TEC perturbation are studied to gain insights into the occurrence of irregular structures in the ionosphere and their distribution. One of the ionospheric irregularities located within the F region, and E region top side are Traveling ionospheric disturbances (TIDs). TIDs are propagating perturbations in the ionospheric electron density as a consequence of Atmospheric Gravity Waves (AGWs) passage. The AGWs originate in the troposphere or stratosphere, and exhibit neutral wind perturbations propagating to the F region heights (i.e. ionospheric heights), where the neutral wind perturbations interact with the plasma via collisions, carrying it along the magnetic field lines (i.e. ion-neutral collision). This entire process in the ionosphere is manifested as oscillations of the ionospheric electron density, resulting in a TID. However, TIDs vary in scale sizes ranging within a few hundred kilometers (km) to over one thousand km, and based on this, they are categorized as either medium-scale TIDs (MSTIDs) or large scale TIDs (LSTIDs). In this thesis, we focus only on MSTIDs as one of the major and frequent ionospheric irregularity phenomena which may degrade positioning systems and could cause a delay in GPS signal transmission between a satellite and the GPS receiver. Multiple studies of ionospheric irregularities with the main focus on MSTIDs over different regions and continents around the world have been carried out, but studies of MSTIDs over the African region have neither been carried out nor reported probably due to lack of GPS data set, and the question of what drives its occurrence in the region which is not yet documented. The objective of this thesis is to study and describe for the first time the occurrence of MSTIDs and its characteristics over the African region under quiet geomagnetic condition (Kp ≤ 3) during the years 2008 – 2016. In addition, this thesis presents novel results of the time series of MSTIDs percentage occurrence rate (POR) during daytime and nighttime, and seasonal occurrence. Ionneutral coupling processes like the connection between AGW and MSTIDs are also discussed in the study. Observational TEC data used in this thesis are obtained from ground-based GPS networks within the African region and nearby stations. Additionally, temperature data from COSMIC radio occultation and SABER satellite observations for some case studies were used to validate AGWs passage as a driving source of MSTIDs, especially during the daytime. Consequently, regional MSTIDs distribution maps have been generated to capture the latitudinal, seasonal, and local time extent of the MSTID occurrence. Investigation of regional ionospheric irregularities over Africa (IRIA) gives a novel result of a climatological view of MSTIDs over Northern and Southern hemispheres in the African region.

Description: This document describes the type of data collected in the REFLECT project, the standards used and how the data is curated. It also elaborates on the relations to IPR requirements and exploitation strategies. All data from the project shall be deposited in research data repositories according to the FAIR guiding principles for scientific data management and stewardship such that it is possible for third parties to access, mine, exploit, reproduce and disseminate — free of charge for any user.

Description: In this interim report, the studies on geothermal fluids carried out in Turkey, France and Iceland geothermal fields are explained.

Description: The ionosphere is a complex and highly variable physical system with the F-layer, which occupies at the highest altitude, contains the greatest concentration of free electrons. Under the extreme circumstance of the ionosphere such as in the periods of high solar activity or magnetic storms or simply in the equinoctial months each year, this layer is very often disturbed. During the disturbances, the small-scale irregularities develop and disperse microwave radio signals, and thus generate rapid fluctuations in the amplitude and phase of satellite signals. This phenomenon causes the ionosphere to be scintillated and is called ionospheric scintillation. The impacts of scintillation cannot be mitigated by the multi-frequency technique that is very effective when dealing with ionospheric delay. Consequently, ionospheric scintillation is one of the most significant threats for space geodetic techniques, especially for stations operating in the polar regions or areas near the equator. To study ionospheric scintillation, alternative methods have been proposed including the method of using high-rate receivers to directly output S4 index over Vietnam region and the method of using standard GNSS dual-frequency to calculate ROTI index on a global scale. Main results of this thesis are the temporal variations of total number electron (TEC) in Southeast Asia for eleven consecutive years and the appearance characteristics of scintillation over this area as well as globally during solar cycle 24 (SC24). For space geodesy, electromagnetic waves are most vulnerable in the equatorial ionization anomaly (EIA) as this region has many potential risks of errors for satellite signals. The research area (Southeast Asia) is also located entirely within the EIA. In this thesis, the temporal - latitudinal VTEC maps have been established to study the modifications of EIA’s structure. Thereby, the featured occurrence of EIA crests in Southeast Asia is revealed. Also, the global morphology of anomaly crests averaged over 11-year period shows the worldwide distribution of EIA crests during SC24. Throughout the thesis, the high consistency between the state of the ionosphere and the activity status of the Sun is evidenced by high correlations between VTEC and solar indices. In which, the radio flux index (F10.7 cm) is proved to be more agreeable to the VTEC development than the sunspot number (SSN). The behaviour of the ionosphere during intense magnetic storms is also investigated. The results show that the structure of EIA is often highly volatile during these severe ionospheric conditions.

Description: Die Ionosphäre ist ein komplexes und hochvariables physikalisches System, wobei die am höchsten gelegene F-Schicht die höchste Konzentration an freien Elektronen enthält. Unter den extremen Bedingungen der Ionosphäre, wie beispielsweise in den Perioden hoher Sonnenaktivität oder magnetischer Stürme oder einfach in den Äquinoktialmonaten eines jeden Jahres, ist diese Schicht der Ionosphäre häufig gestört. Während der Störungen propagieren und zerstreuen die kleinräumigen Unregelmäßigkeiten Mikrowellen-Radiosignale und erzeugen so schnelle Schwankungen in der Amplitude und in der Phase der Satellitensignale. Dieses Phänomen führt zu einer Szintillation der Ionosphäre und wird oft als ionosphärische Szintillation bezeichnet. Im Prinzip können die Auswirkungen der Szintillation nicht durch die Mehrfrequenztechnik verringert werden, die bei der Behandlung der ionosphärischen Verzögerung sehr effektiv ist. Aus diesen Gründen ist die ionosphärische Szintillation eine der größten Herausforderungen für geodätische Weltraumtechniken, insbesondere für Messstationen, die in den Polarregionen oder in äquatornahen Gebieten einschließlich Südostasiens arbeiten. Zur Untersuchung der ionosphärischen Szintillation wurden alternative Methoden vorgeschlagen, darunter die Methode der Verwendung von Hochfrequenz-Empfängern zur direkten Ausgabe des S4-Index über der Region Vietnam und die Methode der Verwendung der standardmäßigen GNSS Zweifrequenzmessungen zur Berechnung des ROTI-Index zur Untersuchung ionosphärischer Unregelmäßigkeiten im globalen Maßstab. Die Hauptergebnisse der Arbeit beinhalten die zeitlichen Variationen des Gesamtelektroneninhalts (total electron content, TEC) in Südostasien für elf aufeinander folgende Jahre und die Erscheinungsmerkmale der Szintillation während des 24. Sonnenzyklus (SC24) sowohl über diesem Gebiet als auch auf globaler Ebene. Für die Weltraumgeodäsie sind elektromagnetische Wellen in der äquatorialen Anomalie der Ionosphäre (equatorial ionization anomaly, EIA) am anfälligsten, da diese Region viele potenzielle Fehlerrisiken für Satellitensignale aufweist, welche bei der Übertragung aus dem Weltraum die Ionosphäre durchqueren. Das Forschungsgebiet (Südostasien) befindet sich ebenfalls vollständig innerhalb der EIA. In dieser Arbeit wurden die zeit und breitenabhängigen Karten des VTEC erstellt, um die Veränderungen der Struktur der EIA zu untersuchen. Dabei wird das charakteristische Vorkommen von Kämmen der EIA-Anomalie in Südostasien offen gelegt. Außerdem zeigt die globale Morphologie der Anomalie-Kämme, gemittelt über einen Zeitraum von elf Jahren, die weltweite Verteilung der EIA-Kämme während des SC24. Der starke Zusammenhang zwischen dem Zustand der Ionosphäre und dem Aktivitätszustand der Sonne wird durch hohe Korrelationen zwischen dem VTEC und den Sonnenindizes einschließlich der Sonnenfleckenzahl (sunspot number, SSN) und dem Radioflussindex F10,7 cm belegt. Auch das Verhalten der Ionosphäre während intensiver magnetischer Stürme wird untersucht. Die Ergebnisse zeigen, dass die Struktur der EIA unter diesen extremen ionosphärischen Bedingungen häufig sehr volatil ist.