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The localization of the North Anatolian Fault in the northern Aegean Sea (North Aegean Trough) is an intriguing example of continental transform fault propagation. Understanding this process critically depends on the quantification of strike-slip displacement and the superposition of normal and strike-slip faulting in the region, which is the aim of this study. In particular, we unravel and quantify normal and dextral faulting along the Alonnisos fault system, at the south-western margin of the North Aegean Trough (Sporades Basin). We present detailed structural data collected from Messinian strata of Alonnisos to infer the amount of post-5 Ma tilting and shortening on the island, and relate them to normal and dextral faulting along the Alonnisos fault system through simple analytical half-space models of dislocations. The Messinian rocks of Alonnisos record significant (13.5°) tilting and gentle folding close to the termination zone of the main fault segment. The tilting of the Messinian rocks was related to footwall uplift during normal faulting (in the order of 6–7 km vertical displacement) along the Alonnisos fault system, which implies that the deepening of the Sporades Basin occurred post-5 Ma. The post-Messinian folding accommodated ∼1 km shortening along the footwall termination zone of the Alonnisos fault and was related to 3–4 km dextral slip, possibly during the last 100–200 kyr. This is the first clear indication of major dextral displacement along the Alonnisos fault system. Our results support interpretations of currently distributed dextral strain in the North Aegean in response to the propagation of the North Anatolian Fault. However, similarities with the evolution of the Sea of Marmara might suggest that dextral shear could yet become fully localized in the NAT.

The Geothermal Capacity Building program GEOCAP, a bilateral program (6MEURO) between Netherlands and Indonesia, has been running since 2013 and is foreseen to continue until 2022. In this public-private partnership we thus have a decade of experience which we share in this session. The session addresses sustainable solutions for geothermal exploration including environment friendly methods, looks at the synergy between surface and subsurface exploration methods, and how to upscale local geologic information to regional prospectivity. In this risk analysis and mitigation, geology as well as economy and the environment are integral components of a multi-disciplinary workflow developed by GEOCAP. Methods for modern exploration of geothermal resources include those derived from remote sensing and earth observation, 3D subsurface/surface (thermo) GIS and modelling, geophysics, geochemistry and engineering. We explore synergies between exploration methods directed towards derisking operations and increasing drilling success rates. In this session through Q&A and open discussion we intend to identify scientific white spots, leading to a preliminary science and policy agenda for future bilateral collaboration on geothermal exploration and education. By emphasizing the focus on (solving) real-world problems we feel there is broad scope for the private sector participation in the session and in setting the agenda. Our target audience are geoscientists, policy makers and private enterprises. This session emphasizes the use of remote sensing public domain images (SAR and thermal) for geothermal exploration, especially in high enthalpy volcanic geothermal systems which generally have significant surface manifestations and are mostly controlled by geological structures, both primary and secondary structures. Some of the developments in remote sensing techniques and methods that have been carried out and the case study of remote sensing analysis in geothermal exploration will also be presented as learning and discussion materials.

This dataset provides friction data from ring-shear tests (RST) on an iron powder – quartz sand mixture (weight ratio 1:3). This material is used in particular as marker material in analogue experiments that are monitored with CT-scanners in the Tectonic Laboratory (TecLab) at Utrecht University (NL) (Pueyo et al., 2017; 2018). The material has been characterized by means of internal friction coefficients µ and cohesions C as a remote service by the Helmholtz Laboratory for Tectonic Modelling (HelTec) at the GFZ German Research Centre for Geosciences in Potsdam in the framework of the EPOS (European Plate Observing System) Transnational Access (TNA) call of the Thematic Core Service (TCS) Multi-scale Laboratories (MSL) in 2017. According to our analysis the material behaves as a Mohr-Coulomb material characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients are µP = 0.65, µD = 0.53, and µR = 0.62, respectively. Cohesions C are in the range of 70 to 100 Pa. A minor rate-weakening of ~3% per ten-fold change in shear velocity v is evident.

Dataset

In this paper we present results of a global resource assessment for geothermal energy within deep aquifers for direct heat utilization. Greenhouse heating, spatial heating, and spatial cooling are considered in this assessment. We derive subsurface temperatures from geophysical data and apply a volumetric heat-in-place method to improve current global geothermal resource base estimates for direct heat applications. The amount of thermal energy stored within aquifers depends on the Earth's heat flow, aquifer volume, and thermal properties. We assess the thermal energy available by estimating subsurface temperatures up to a depth of three kilometer depending on aquifer thickness. The distribution of geothermal resources is displayed in a series of maps and the depth of the minimum production temperature is used as an indicator of performance and technical feasibility. Suitable aquifers underlay 16% of the Earth's land surface and store an estimated 4·105 to 5·106 EJ that could theoretically be used for direct heat applications. Even with a conservative recovery factor of 1% and an assumed lifetime of 30 years, the annual recoverable geothermal energy is in the same order as the world final energy consumption of 363.5 EJ yr−1. Although the amount of geothermal energy stored in aquifers is vast, geothermal direct heat applications are currently underdeveloped with less than one thousandth of their technical potential used. © 2017 The Author(s)

Large-scale folding is a key mechanism of lithospheric deformation and has been described in many parts of the Earth, both for the continental and oceanic lithospheres. Some aspects of this process such as the presence of coupling/decoupling between the crustal deformation and the mantle lithosphere, or between different lithospheres, make it necessary to accurately control the periodic characteristics of the elevation and of the gravity signal. 1D spectral analysis of gravity and topography profiles is sensitive to a series of factors: the location, length and orientation of the profiles, as well as the number of samples taken. We carry out a systematic analysis of the periodicities in the topography and gravity, both 1D and 2D, along the western border of the Africa–Eurasia plate tectonic boundary. We analyze the sensitivity of the 1D and 2D spectral analysis in order to compare the results along a plate boundary where oceanic and continental lithospheres are in contact with different tectonic, kinematic and rheological aspects. Our 1D spectral results indicate that the greater the profile length, the longer the wavelength peaks that are found. Nevertheless there are some periodic signals that appear in almost all the analyzed profiles: 100–250 km for the N–S profiles across oceanic plate boundary and 150–250 km where the plate boundary is developed over continental lithospheres. The 2D spectral analysis avoids the problems found in relation to the particular location of the profile but the resulting wavelengths are slightly higher than those obtained from the 1D spectral analysis. The wavelengths estimated for both oceanic and continental lithospheres at the Africa–Eurasia boundary (N250 km) show low values of mean mantle strength (b1013 Pa m). he presence of lithospheric folds means that the continental and oceanic lithospheres are mechanically oupled. This had previously been suggested for Iberia but not for the limit between S Iberia and the Terceira riple Junction. The orientation of the lithospheric folds is NW–SE at the contact between continental lithospheres and NNE–SSW at the contact between oceanic lithospheres. This difference is also reflected in the signal anisotropy and must be related to the rotation of the tectonic stresses in the same direction. A large periodic signal (wavelength N600 km) was also detected both in 1D and 2D spectral results. After drawing the filtered values, the resulting maps indicate that this signal is related to the transition between continental and oceanic lithospheres and to the significant changes in crustal and/or lithospheric thickness from the Mid-Atlantic Ridge to the continental margins of western Eurasia.

The tectonic evolution of sedimentary basins is the intrinsic result of the interplay between lithospheric stresses, lithospheric rheology, and thermal perturbations of the lithosphere–upper mantle system. The thermomechanical structure of the lithosphere exerts a prime control on its response to basin-forming mechanisms, in both extension and compression. Tectonic reactivation has strongly affected the structure and fill of many sedimentary basins. The long-lasting rheological memory of the lithosphere appears to play a far more important role in basin reactivation than hitherto assumed. The temporal evolution of the strength of continents and the spatial variations in stress and strength at continental margins, rifts, and orogenic belts govern the mechanics of basin development in time and space. Polyphase deformation is a common feature of many sedimentary basin systems. Compressional reactivation of extensional basins during their postrift phase appears to occur in many intraplate rifts and passive margins, reflecting temporal and spatial changes in the orientation and magnitude of the intraplate stress regime. Similarly, foreland basins are frequently characterized by preorogenic extension. The actual subsidence patterns of these polyphase systems are often more complex than predicted by end-member models that only consider the basin formation mechanism. Folding of the lithosphere, involving positive and negative deflections, appears to be of more importance in the large-scale deformation of intraplate domains than hitherto realized. In the intraplate domain of continental Europe that was thermally perturbed by Cenozoic upper mantle plume activity, lithospheric folding, for instance, plays an important role and strongly affects the pattern of vertical motions, in terms of both the basin subsidence and the uplift of broad arches. Tectonic processes operating during basin formation and during the subsequent deformation of basins can generate significant differential topography in basin systems. In view of the close link between erosion of topographic highs and sedimentation in subsiding areas, constraints are needed on uplift and coeval subsidence to validate quantitative process-oriented models for the evolution of sedimentary basins. Integration of analog and numerical modeling provides a novel approach to assess the feedback mechanisms between deep mantle, lithospheric, and surface processes.