Near‐surface fault detection using high‐resolution shear wave reflection seismics at the CO2CRC Otway Project site, Australia

High‐resolution, near‐surface, shear wave reflection seismic measurements were carried out in November 2013 at the CO2CRC Otway Project site, Victoria, Australia, with the aim to determine whether and, if so, where deeper faults reach the near subsurface. From a previous P wave 3‐D reflection seismic data set that was concentrated on a reservoir at 2 km depth, we can only interpret faults up to 400 m below sea level. For the future monitoring in the overburden of the CO2 reservoir it is important to know whether and how the faults continue in the subsurface. We prove that two regional fault zones do in fact reach the surface instead of dying out at depth. Individual first‐break signatures in the shot gathers along the profiles support this interpretation. However, this finding does not imply perforce communication between the reservoir and the surface in the framework of CO2 injection. The shear wave seismic sections are complementary to existing P wave volumes. They image with high resolution (better than 3 m vertically) different tectonic structures. Similar structures also outcrop on the southern coast of the Otway Basin. Both the seismic and the outcrops evidence the complex youngest structural history of the area.BMBF, 03G0797A, Verbundprojekt UR VI: PROTECT; Vorhersage von Deformation für eine abgesicherte Speicherung von Kohlenstoff (PRediction Of deformation To Ensure Carbon Traps); Vorhaben: Subseismische Deformationsvorhersage potentieller Wegsamkeiten und ihre seismische Validierung - Sonderprogramm GEOTECHNOLOGIE

Neuropsychosocial profiles of current and future adolescent alcohol misusers

A comprehensive account of the causes of alcohol misuse must accommodate individual differences in biology, psychology and environment, and must disentangle cause and effect. Animal models1 can demonstrate the effects of neurotoxic substances; however, they provide limited insight into the psycho-social and higher cognitive factors involved in the initiation of substance use and progression to misuse. One can search for pre-existing risk factors by testing for endophenotypic biomarkers2 in non-using relatives; however, these relatives may have personality or neural resilience factors that protect them from developing dependence3. A longitudinal study has potential to identify predictors of adolescent substance misuse, particularly if it can incorporate a wide range of potential causal factors, both proximal and distal, and their influence on numerous social, psychological and biological mechanisms4. Here we apply machine learning to a wide range of data from a large sample of adolescents (n = 692) to generate models of current and future adolescent alcohol misuse that incorporate brain structure and function, individual personality and cognitive differences, environmental factors (including gestational cigarette and alcohol exposure), life experiences, and candidate genes. These models were accurate and generalized to novel data, and point to life experiences, neurobiological differences and personality as important antecedents of binge drinking. By identifying the vulnerability factors underlying individual differences in alcohol misuse, these models shed light on the aetiology of alcohol misuse and suggest targets for prevention

Differential predictors for alcohol use in adolescents as a function of familial risk

Abstract: Traditional models of future alcohol use in adolescents have used variable-centered approaches, predicting alcohol use from a set of variables across entire samples or populations. Following the proposition that predictive factors may vary in adolescents as a function of family history, we used a two-pronged approach by first defining clusters of familial risk, followed by prediction analyses within each cluster. Thus, for the first time in adolescents, we tested whether adolescents with a family history of drug abuse exhibit a set of predictors different from adolescents without a family history. We apply this approach to a genetic risk score and individual differences in personality, cognition, behavior (risk-taking and discounting) substance use behavior at age 14, life events, and functional brain imaging, to predict scores on the alcohol use disorders identification test (AUDIT) at age 14 and 16 in a sample of adolescents (N = 1659 at baseline, N = 1327 at follow-up) from the IMAGEN cohort, a longitudinal community-based cohort of adolescents. In the absence of familial risk (n = 616), individual differences in baseline drinking, personality measures (extraversion, negative thinking), discounting behaviors, life events, and ventral striatal activation during reward anticipation were significantly associated with future AUDIT scores, while the overall model explained 22% of the variance in future AUDIT. In the presence of familial risk (n = 711), drinking behavior at age 14, personality measures (extraversion, impulsivity), behavioral risk-taking, and life events were significantly associated with future AUDIT scores, explaining 20.1% of the overall variance. Results suggest that individual differences in personality, cognition, life events, brain function, and drinking behavior contribute differentially to the prediction of future alcohol misuse. This approach may inform more individualized preventive interventions

Differential predictors for alcohol use in adolescents as a function of familial risk

Abstract: Traditional models of future alcohol use in adolescents have used variable-centered approaches, predicting alcohol use from a set of variables across entire samples or populations. Following the proposition that predictive factors may vary in adolescents as a function of family history, we used a two-pronged approach by first defining clusters of familial risk, followed by prediction analyses within each cluster. Thus, for the first time in adolescents, we tested whether adolescents with a family history of drug abuse exhibit a set of predictors different from adolescents without a family history. We apply this approach to a genetic risk score and individual differences in personality, cognition, behavior (risk-taking and discounting) substance use behavior at age 14, life events, and functional brain imaging, to predict scores on the alcohol use disorders identification test (AUDIT) at age 14 and 16 in a sample of adolescents (N = 1659 at baseline, N = 1327 at follow-up) from the IMAGEN cohort, a longitudinal community-based cohort of adolescents. In the absence of familial risk (n = 616), individual differences in baseline drinking, personality measures (extraversion, negative thinking), discounting behaviors, life events, and ventral striatal activation during reward anticipation were significantly associated with future AUDIT scores, while the overall model explained 22% of the variance in future AUDIT. In the presence of familial risk (n = 711), drinking behavior at age 14, personality measures (extraversion, impulsivity), behavioral risk-taking, and life events were significantly associated with future AUDIT scores, explaining 20.1% of the overall variance. Results suggest that individual differences in personality, cognition, life events, brain function, and drinking behavior contribute differentially to the prediction of future alcohol misuse. This approach may inform more individualized preventive interventions

Geological 3-D model as 3-D PDF and mve files

The 3-D PDF shows the 3-D model, including all interpreted stratigraphic horizons and faults as triangulated surfaces. To activate the 3-D PDF, the user has to click once in the black background and wait. After a few seconds it should be possible to get a 360° view around the 3-D model and to toggle horizons/faults/wells on and off. In a standard PDF viewer it is possible to create custom 2-D sections along X, Y or Z axes through the 3-D model. Due to technical issues it is not possible to convert a 3-D PDF into a 3-D PDf with PDF/A standard. The zip folder "Move_projects" contains different .mve files that were used for the retro-deformation of the geological 3-D model. Every single decompaction and restoration step was saved as extra .mve file

Vorhersage von seismischer und sub-seismischer Deformation zur Gewährleistung der Sicherheit eines CO2 Speichers im Otway Becken, Australien

In the framework of CO2 capture and storage (CCS), it is important to determine fluid migration pathways that occur between reservoir and surface, because this allows an estimation of the long-term storage integrity. This cumulative thesis deals with this topic and is embedded in the PROTECT (PRediction Of deformation To Ensure Carbon Traps) project. The project cooperates with Australia’s first demonstration site of deep geological storage of CO2 in the Otway Basin (state of Victoria). To predict and quantify the amount of seismic and sub-seismic deformation caused by fault movement, a baseline 3-D seismic of the CCS site was analysed. The first step was to build a structural 3-D model by interpretation of eight stratigraphic horizons and 24 major faults within a ca. 8km x 7km x 3km study area. The high-resolution 3-D model shows a complex system of south-dipping normal faults and north-dipping antithetic normal faults. Vertical displacements within the reservoir formation increase from north to south to a maximum of ca. 800 m. Based on Allan maps, isopach maps, and expansion index analyses, I determined that all major faults are growth faults that were constantly active from Early Cretaceous (ca. 110 Ma) until Late Paleocene (ca. 65 Ma). Two faults in the northern part of the study area have been recently active. One of the most important results of this work is that two different types of fault kinematics were simultaneously active: 40% of the faults show a component of dextral oblique-slip movement, while the rest of the faults shows pure dip-slip movement. The next step was the complete 3-D retro-deformation and the calculation of strain tensor maps within the faulted stratigraphic formations to locate highly deformed or fractured zones. The question of which kinematic restoration algorithm to use is essential for realistic results. I decided to use the ‘inclined shear’ algorithm, because the fault-parallel flow algorithm should be limited to the restoration of compressional faults, where fault bend angles do not exceed 40°. By retro-deforming the complete 3-D model, sub-seismic scale deformation was analysed. For the first time, compaction- and deformation-related strain for the whole study area were separately evaluated. The overburden strata down to the 1.5km deep Skull Creek Formation (seal) contains only minor sub-seismic strain caused by fault deformation (max. 15%). In contrast, the Skull Creek Formation has minimum strain values caused by fault movement of 30%. The strain results show a tripartition of the study area, in which most deformation (30–50%) occurs in the south-western part. The tripartition is caused by four major faults that acted as ‘controlling faults’ with smaller faults in between. The distribution of potential sub-seismic pathways was determined within the seal horizon, but they do not continue into the overburden. A supplementary 3-D PDF presents the 3-D geological model, from which all the results were derived. The workflow, the methods, and the results presented in this thesis can be used to evaluate the safety of a reservoir in future projects.Im Bereich CO2-Abscheidung und -Speicherung (CCS) ist die Abschätzung von Fluidwegsamkeiten zwischen dem Reservoir und der Oberfläche für die Langzeitsicherheit der Speicher wichtig. Diese kumulative Dissertation ist ein Teil des Projektes PROTECT (PRediction Of deformation To Ensure Carbon Traps), das mit Australiens erstem Demonstrationsprojekt für CO2-Speicherung im Otway Becken (Bundesstaat Victoria) kooperiert. Dazu wurde ein seismischer 3-D Datensatz des Untersuchungsgebietes für die Vorhersage und Quantifizierung von Deformation im seismischen und sub-seismischen sichtbaren Bereich analysiert. Der erste Schritt war die Erstellung eines 3-D Strukturmodells. Hierfür wurden in der 3-D Seismik acht stratigraphische Horizonte und 24 Hauptstörungen eines ca. 8km x 7km x 3km großen Arbeitsgebietes interpretiert. Das hochauflösende 3-D Modell zeigt ein komplexes System von nach Süden einfallenden Abschiebungen und nach Norden einfallenden antithetischen Verwerfungen. Der vertikale Versatz innerhalb der Reservoirformation nimmt von Norden nach Süden bis maximal 800m zu. Allan Maps, Mächtigkeitskarten und Expansionindizes zeigen, dass alle Hauptverwerfungen Wachstumsstörungen sind, die seit der frühen Kreidezeit (ca. 110 Ma) bis ins späte Paläozen (ca. 65 Ma) konstant aktiv waren. Zwei Störungen im nördlichen Bereich des Arbeitsgebietes sind gegenwärtig noch aktiv. Insbesondere wurden zwei Arten von Störungskinematik ermittelt: 40% der Abschiebungen sind durch eine leichte dextrale Bewegungsrichtung gekennzeichnet,während die restlichen Störungen reine Abschiebungen sind. Der nächste Schritt war die vollständige 3-D Retrodeformation und die Berechnung des Verformungstensors, um stark deformierte bzw. brüchige Zonen innerhalb der stratigraphischen Formation zu lokalisieren. Für realistische Ergebnisse ist die Verwendung des richtigen Algorithmus zur kinematischen Restaurierung entscheidend. Die Analyse des ‘Fault-Parallel Flow’-Algorithmus zeigt, dass dieser sich nur für Aufschiebungen mit einem Störungswinkel kleiner 40° eignet. Im Gegensatz dazu liefert der ‘Inclined Shear’ Algorithmus die besten Resultate für das Arbeitsgebiet. Als Ergebnis wird die Verformung auf sub-seismischer Skala vorgestellt. Für das gesamte Arbeitsgebiet konnte zum ersten Mal die durch Kompaktion verursachte Verformung von der durch Deformation verursachten Verformung separat untersucht werden. Die überlagernden Schichten der 1.5km tiefen Skull Creek Formation (Deckschicht) sind durch eine geringe subseismische Verformung gekennzeichnet (max. 15%). Im Gegensatz dazu enthält die Skull Creek Formation mindestens 30% Verformung, die durch die Bewegung entlang der Störung verursacht wurde. Die Verformungsergebnisse zeigen außerdem eine Dreiteilung des Arbeitsgebietes mit der höchsten Deformation (30–50%) im Südwesten. Diese Dreiteilung wird durch vier übergeordnete Hauptstörungen mit kleineren Verwerfungen dazwischen verursacht. Die Verteilung der potentiellen sub-seismischen Wegsamkeiten wurde für die Deckschicht bestimmt, jedoch setzen sie sich nicht in die darüber liegenden Schichten fort. Zusätzlich wird das geologische 3-D Modell, von dem alle Ergebnisse abgeleitet wurden, in einem 3-D PDF präsentiert. Die Arbeitsabläufe, Methoden und Ergebnisse dieser Dissertation können genutzt werden, um in zukünftigen Projekten die Sicherheit eines Reservoirs besser abzuschätzen.BMBF, 03G0797A, Prediction of deformation to ensure carbon trap

Near-surface fault detection using high-resolution shear wave reflection seismics at the CO2CRC Otway Project site, Australia

High-resolution, near-surface, shear wave reflection seismic measurements were carried out in November 2013 at the CO2CRC Otway Project site, Victoria, Australia, with the aim to determine whether and, if so, where deeper faults reach the near subsurface. From a previous P wave 3-D reflection seismic data set that was concentrated on a reservoir at 2 km depth, we can only interpret faults up to 400 m below sea level. For the future monitoring in the overburden of the CO2 reservoir it is important to know whether and how the faults continue in the subsurface. We prove that two regional fault zones do in fact reach the surface instead of dying out at depth. Individual first-break signatures in the shot gathers along the profiles support this interpretation. However, this finding does not imply perforce communication between the reservoir and the surface in the framework of CO2 injection. The shear wave seismic sections are complementary to existing P wave volumes. They image with high resolution (better than 3 m vertically) different tectonic structures. Similar structures also outcrop on the southern coast of the Otway Basin. Both the seismic and the outcrops evidence the complex youngest structural history of the area