Recent advances in computational capabilities make it possible to compute global geodynamic earth models at near earthlike convective vigor. This paves the way to systematically obtain a range of synthetic data from such models in an approach that is known as closed loop experiments. Here we present results from closed loop experiments in geodynamic earth models targeted at three classes of data that are sensitive to the mantle convection process, namely seismic data, global stress patterns as reflected by the world stress map, and continent scale stratigraphy processed for the distribution of conformable and unconformable successions in recently developed so called hiatus maps. Our results reveal effects from spatially variable data collection and quality (as expected), mantle flow geometries (less expected) and (still poorly known) histories of paleo mantle flow. We conclude that the derivation of process based synthetic data from geodynamic earth models provides crucial information for data interpretion, that closed loop experiments area powerful tool to link geodynamic earth models to data, and that closed loop experiments could be helpful to guide future data collection efforts.

The Variscan basement units of the Bohemian Massif and other Variscan domains in Central Europe are thought to be less affected by Cenozoic tectonics. However, analyses using geomorphic indices and river profiles reveal spatial variations in the evolved topography in the Bavarian Forest, the southwestern segment of the Bohemian Massif. The geomorphic analyses suggest disequilibrium along drainage divides and in river profiles. It has been suggested that the topography in the southern parts of the Bohemian Massif has rejuvenated (Zebari et al., 2024). However, interpretations aimed at extracting tectonic signals from geomorphic analysis are inherently relative, and it is sometimes challenging to separate tectonic signals from climate signals or differential erodibility. To further quantify landscape dynamics in the Bavarian Forest, we estimated long-term watershed-averaged denudation rates from in-situ produced 10Be cosmogenic nuclide analysis of sand samples collected from outlets of 15 representative watersheds in the Bavarian Forest.Our initial results indicate that watershed-averaged denudation rates in the Bavarian Forest range from 21.1 ± 2.4 to 40.5 ± 4.8 mm/kyr. These denudation rates represent a time period equivalent to the removal of approximately 60 cm of rocks, corresponding to about 15 kyr for the fastest-eroding watershed and about 28.5 kyr for the slowest one. There are spatial variations in the denudation rates, with the watersheds clustering into several distinct subregions. Overall, watersheds in the southeast, within or around the Ilz catchment, and those in the high-elevation areas of the Hinterer Bayerischer Wald, have relatively higher denudation rates than those in the central segment of the Vorderer Bayerischer Wald. Furthermore, notable differences are also found across the drainage divide between the Regen and Danube rivers in the adjacent watersheds, and these differences are consistent with the analysis of drainage divide dynamics using the χ (Chi) integral. Additionally, the calculated denudation rates also correlate with the topographic metrics of watershed and river profiles.The same climatic conditions and minimal contrast in rock erodibility are expected for the adjacent watersheds in the Bavarian Forest; therefore, these denudation rates may represent a brief time window within a longer span of tectonic processes that shaped the relief there. Broad surface uplift of the Northern Alpine Foreland Basin and beyond, since prior to 6 Ma, and associated drainage network reorganization may have also affected the southern regions of the Bohemian Massif, resulting in the rejuvenation of topography in the Bavarian Forest, notably within its southeastern part. Thus, it is expected that the driving forces for the broad-scale recent surface uplift event(s), which affected the Bavarian Forest, also reactivated the major bounding faults.References:Zebari, M., Friedrich, A. M., Ludat, A. L., Kahle, B., Rieger, S. M., & Kübler, S. (2024). The role of late Cenozoic intraplate tectonic in shaping the topography of the Bavarian Forest, southwestern Bohemian Massif, Germany. Geologica Bavarica, 130: 35–55.

Our understanding of plate tectonics and mantle convection has made significant progress in recent decades, yet the specific impact of mantle plumes on plate tectonics remains a topic of controversy. The motions of the Earth’s lithosphere serves as a powerful lens into the dynamic behavior of the asthenosphere and deeper mantle, helping to untangle such controversies. Surface observations, therefore, provide important constraints on mantle convection patterns through space/time. Among these observations, the record of plate motion changes stands out, as it enables the geographical identification of torque sources. Consequently, surface observations provide essential constraints for theoretical models and numerical simulations. The analytical Poiseuille flow model applied to upper mantle flux in the asthenosphere offers a robust and testable prediction: Poiseuille flow induced plate motion changes should coincide with regional scale mantle convection induced elevation changes. Mantle plumes can generate such pressure driven flows, along with intraplate magmatism and induce buoyancy-driven uplift that leaves an imprint in the sedimentary record. Here, I will present a synthesis of geological and geophysical observations, supported by analytical calculations, to illustrate that a significant number of plate motion changes can be attributed primarily to torques originating from mantle plumes.

Salt diapirs are ubiquitous in the Zagros Mountains, but salt-flow dynamics in their extrusive parts and interaction with their caprocks are complex and poorly understood. For a better understanding of the interaction between salt dynamics and the caprock on the surface of the salt extrusions, knowledge of high-resolution spatiotemporal surface deformation and multispectral satellite imagery analysis is essential. However, the contemporary vertical surface deformation pattern across salt diapirs is difficult to detect and interpret along disciplinary boundaries. With the aid of high-resolution PSI measurements and multispectral imagery analysis we detected high-precision spatiotemporal deformation patterns of the surfaces of salt diapirs and their caprocks. Furthermore, time-series analysis helped to distinguish between salt-supply-driven domal uplift and vertical surface modification induced by precipitation, dissolution, and erosion. In this study, we analysed Sentinel-1 PSI time-series, processed by the German Aerospace Center (DLR), to obtain the highest available spatiotemporal resolution of the vertical surface-deformation pattern across three diapirs – Karmostaj, Siah Taq, and Champeh – in the Zagros. Furthermore, the Persistent Scatterers are correlated to their lithological composition based on multispectral analysis of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite images. Preliminary results indicate that the deformation pattern of the salt diapirs does not correlate with seasonal effects, such as precipitation and heat. The vertical surface deformation pattern on these three diapirs implies that these diapirs are active and that caprock influences the salt flow pattern. Unnderstanding the activity of salt diapirs in general is also important, for example, in the feasibility studies of salt diapirs as strategic storage facilities for hydrocarbons, waste material, and CO2 storage over longer time-scales worldwide.

Deformation in the Earth’s upper crust is typically accommodated by faults, which can range from microscopic displacements to regional tectonic features. Despite being located in the continental interior of the Eurasian plate, Central Europe displays notable evidence for recent activity, including active faulting, even along fault lines previously presumed inactive. This intraplate region has experienced multiple phases of fault reactivation, which provide the basis for debate regarding the underlying causative deformation mechanisms and driving forces. Determining the timing of episodic fault activity and their deformation rates is crucial to investigating the mechanisms behind Cretaceous to Paleocene exhumation and its relationship to more recent fault activity. An excellent region for this purpose is the Bohemian Massif, which is characterized by a complex structural and lithological architecture recording a long history of deformation. This area hosts significant fault zones, such as the NW–SE-striking Pfahl and Danube faults. Despite being one of the largest faults in Central Europe with a prominent scarp and young morphology, the ages of inception and reactivation of the Danube fault remain poorly constrained. Furthermore, therefore, seismic risks associated with these significant intraplate faults are difficult to include in earthquake hazard catalogs. To determine the timing of fault-slip and re-activation of the intracontinental Danube fault system in the Bavarian forest, we designed a sampling strategy involving multiple radiometric geochronometers and judiciously sampled transects across minor faults exposed in numerous quarries. We are currently dating authigenic and synkinematically recrystallized minerals, including U-Pb dating of slickenfiber calcite and K-Ar dating of illite. We also employ 40Ar/39Ar thermochronology and multi-domain diffusion modeling of potassium-bearing minerals of the granitoid host rocks to determine the timing of exhumation and re-setting of this system due to fault activity. The earliest time constraint for the initiation of the Danube fault was established by using published U-Pb zircon ages of deformed granites (310 to 342 Ma) (Klein et al. 2008 Lithos 102). We anticipate the K–Ar ages of illite and U–Pb ages of calcite to be significantly younger, which would confirm potential phases of reactivation accompanied by fluid alteration during cataclastic deformation. These fluid-infiltration events could potentially serve as markers for dating various phases of fault reactivation, which, along with information from frictional resetting, offer insights into the dynamic evolution of the Danube fault over time.

The Makran Subduction Zone (MSZ) of Iran and Pakistan, where the oceanic Arabian plate is sinking beneath the overriding continental Eurasian plate, is among the least explored subduction zones. Limited geodetic measurements, especially in the Western MSZ (WMSZ) with lower seismicity, have posed challenges in assessing the potential for future seismic events. The extensive spatial coverage offered by the Interferometric Wide-Swath (IW) mode of Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) allows for measuring tectonic deformation at a scale of millimeters per year across distances spanning hundreds of kilometers. Nevertheless, the presence of other signals and errors­­­­­—with similar spatio-temporal patterns to the signal of interest—poses challenges to accurately estimating the low-amplitude, large-scale subduction-induced deformation from InSAR observations. In this contribution, we analyze more than eight years of continuous Sentinel-1 InSAR data from both ascending and descending orbits in the WMSZ area of Iran, to capture the Line-Of-Sight (LOS) interseismic crustal deformation rate. Our approach integrates a comprehensive and novel atmospheric mitigation strategy, accompanied by corrections for non-tectonic processes and rigid plate motion, aiming to isolate the tectonic-related signal from other non-tectonic signals and errors. In the following step, we investigate three trench-perpendicular profiles to infer the spatial and along-dip distribution of plate coupling from the Line-Of-Sight (LOS) deformation rates obtained through InSAR. Due to the limited InSAR coverage near the trench (as located beneath the sea), it is not possible to constraint coupling in that area that extends 150 km far from the trench and reaches a depth of 10 km. Our findings reveal significant variations in interseismic coupling from west to east. We observe regions of weak and strong coupling, located near Jask (the westernmost part of the WMSZ) and Chabahar (the easternmost part of the WMSZ), respectively. The middle profile, located near the epicenter of a 5.9 magnitude earthquake that occurred in 1989 (Mw 5.9), exhibits a moderate coupling of 65 percent. Additionally, the coupling is notably high at depths between 10 and 20 km, gradually decreasing to zero at depths between 30 and 40 km. In summary, the enhanced spatial resolution of InSAR, along with the high precision of deformation rates provided by the advanced error mitigation on the long time series of Sentinel-1 significantly improves our ability to characterize the locking depth at which the boundaries between two plates are accumulating stress in WMSZ.

Over a hundred salt diapirs, which are fed by the Precambrian Hormuz Evaporites, extrude through anticlines of the fold and thrust belt of the Zagros Mountains in southern Iran. The sheer number of diapirs, the arid climate, and the mountainous landscape have presented a long-standing challenge for traditional geological field mapping to produce high-resolution lithological maps of prominent salt features. Such maps are crucial for comprehending the role of salt diapirism in the evolution of the landscape and exploring hydrocarbon and mineral resources within the region. To overcome this challenge, we take advantage of the rapidly expanding satellite imagery database to explore the potential of employing satellite-based multispectral and hyperspectral remote sensing for producing lithological maps of salt diapirs in arid environments. Enhancing this analysis with mineral and rock spectroscopy, our goal is to map diverse lithologies characteristic of salt diapir cupolas and genetically associated salt glaciers at the resolution permitted by currently available satellite imagery. To test the utility of satellite-based remote sensing to lithological mapping of salt diapir features, our study focuses on three salt diapirs — Karmostaj, Siah Taq, and Champeh — in the Zagros Mountains. We used previously established ASTER-based NIR and SWIR mineral indices (Cudahy et al., 2020; Hewson et al., 2005; Rowan & Mars, 2003; Shuai et al., 2022) to delineate the distribution of SO42--, Al-OH-, Mg-OH-, and CO32--bearing minerals, and of ferric and clay minerals. We also investigated potential temporal and seasonal changes in the distribution of the target minerals and the strength of the spectral signals of the mineral groups. Furthermore, we calculated mineral indices from ASTER thermal imagery suggested in previous work (Guha & Vinod Kumar, 2016; Ninomiya et al., 2005; Rockwell & Hofstra, 2008) to map quartz-, sulfate-, and carbonate-bearing rocks. To validate the accuracy and precision of the ASTER-based mineral indices, we carried out Raman and FTIR spectroscopic analysis to spectrally characterize rock and mineral samples collected from cupolas, caprocks, and country rocks of various salt diapirs in the region. We subsequently applied Spectral Information Divergence (SID) classification on multispectral ASTER and hyperspectral EnMAP optical imageries. As we extend the mapping technique to other salt diapirs across the Zagros and Arabian Peninsula regions, our findings suggest that satellite-based remote sensing offers a cost-effective and labour-saving approach for generating high-resolution lithological maps. This method has the potential to advance our understanding of the halo-tectonic evolution of the Zagros landscape once a sufficient number of salt diapirs are mapped at the current resolution. However, we note that the accuracy of lithological mapping is influenced by the spectral and spatial resolution of the available satellite imagery. Furthermore, the strength of the spectral signal of gypsiferous outcrops exhibits distinct seasonality, weakening in warm periods and strengthening in cold seasons. In conclusion, our study demonstrates the efficiency as well as the limitations of satellite-based remote sensing in improving lithological maps of exposed salt diapirs in desert environments, providing valuable insights for geological research and resource exploration in the Zagros Mountains.

We tested whether public high-resolution airborne LiDAR data could be suitable for structural geology applications by comparing fracture orientation measurements on Virtual Outcrop Models (VOMs) to field measurements from the same outcrops. We found that the fundamental requirement for taking full advantage of such data is good bedrock exposure, which is also dependent on lithology. Whenever this requirement is satisfied, VOM measurements are comparable to field measurements. VOMs can help considerably in both reducing the time it takes to collect measurements, and in expanding the area in which measurements can be collected without adding significantly to the time budget. They are also especially useful in remote regions and at high elevations, where access is more difficult and yet good exposures are more likely to be found, and they should always be used when planning field work. At present the main limitations, apart from LiDAR coverage not yet existing in places, are due to the hardware and software capabilities needed to create and especially to analyze VOMs.

Oman is situated in the southeastern Arabian plate, just behind the Makran subduction zone. The internal stability of this portion of the Arabian plate must be questioned, however, based on recent studies focusing on long-term observations. These studies provide evidence of active deformation in the Hajar mountains of northern Oman and the UAE. Specifically, recent studies that focused on vertical deformation, yielded temporally and spatially variable vertical rates ranging from 0.01 to 0.89 mm/a in northeastern region of the Arabian Peninsula (Hoffman et al., 2020). Others presented evidence of the continuing uplift of some domes in the Hajar mountains. Furthermore, a significant seismic contrast is well-documented along the Makran subduction zone in Iran and Pakistan. This provides an opportunity to study whether the regional-scale uplift pattern of the Hajar mountains correlates with the variability in deformation style along the Makran plate interface or is caused by driving forces unrelated to horizontal plate motion and subduction. Monitoring the contemporary motions of the northeastern boundary of the Arabian plate can, therefore, enhance our understanding of the complex kinematics of the Makran region. Here, we provide first results of our space-geodetic study in which we combine, both, vertical and horizontal motion analysis to determine the present-day 4D-temporal and spatial strain variability across Oman. The National Survey Authority (NSA) that runs the GNSS reference network across the Sultanate of Oman, established a continuously operating network of 47 sites in 2016. Since its establishment, the network served numerous positioning and mapping activities within the country, providing a precise tool to study the internal deformation of the southeastern Arabian plate. Six-and-a-half years of continuous data acquisition were utilized in our study, combined with 26 IGS stations, to derive horizontal and vertical displacement rates, initially in ITRF20. A new regional reference frame for Oman was realized by rotating ITRF20 so that the horizontal velocities of the Oman CORS stations are minimized in the new reference frame ONGD23. As a result of this process, the average rigid-body rotation of the Arabian plate was estimated and eliminated. The residual velocities illustrate internal horizontal and vertical deformation across Oman, ranging from fractions of millimeters per year to a few millimeters per year. The spatial pattern varies from 1.5 mm/a subsidence in the north to 0.1 mm/a uplift in the northeast. Subsidence of 1.2 to 1.8 mm/a is documented around oil fields. The results also yield uplift rates of up to 0.8 mm/a near certain domes of the Hajar mountains. A noticeable pattern of subsidence transitioning to uplift, from west to east, is observed across the Hajar mountains. Surprisingly, however, the southern flanks of the mountains yield gradual uplift rates. The Arabia – Eurasia plate convergence cannot be directly responsible for such regional scale uplift. Additional mechanisms must be invoked to explain this enigmatic intra-plate strain.

Understanding the evolution of the crustal kinematic/dynamic response of the Kahramanmaraş triple junction after the occurrence of the destructive earthquake doublet on 6 February 2023 is of great interest to seismologists and geodesists. Along with the near-field postseismic effects such as the afterslip, it is also essential to study relatively far-field effects where the interaction of the brittle upper crust with the lower crust and upper mantle can be relevant in how the stress is redistirbuted during the months/years following the earthquake. The latter seems to be a particularly interesting problem for this case because the earthquake perturbation to the interseismic velocity field is very significant and extends approximately 400 km to the west of the rupture zone. The affected region seemingly comprises a large part of the Central Anatolian Block where the interseismic internal deformation was less than 10 nanostrain/yr prior to the large event. Most tomographic studies show that the lithospheric mantle beneath Central Anatolia is either very thin or absent. This indicates a necessity to test various upper mantle and lower crust viscosity scenarios for the far-field effects.We conducted a GNSS (Global Navigation Satellite System) campaign in July 2023, reoccupying 18 sites around the triple junction area to monitor the intermediate and far-field post-seismic effects caused by the ruptures and the subsequent loading behavior of the faults therein. Our primary aim was to characterize: (1) the postseismic effect on the relatively far-field, which likely includes viscoelastic responses in central Anatolia where the lower crust and mantle are presumably weak; (2) variations of the strain field stemming from aftershocks of the large earthquakes; and (3) the response of secondary faults such as the Ecemiş, Deliler, and Sariz faults in Adana and Kayseri provinces. 1-year GNSS time series of continuous stations broadly reveal the postseismic field behavior. The occurence of a postseismic signal is clear northwest of the rupture zone however, the signal is weak for the stations southwest of the earthquake area. The preliminary analysis of the survey mode sites is in agreement with continuous stations. Here we present the resulting post-seismic velocity, the strain rate field and its contrast from the pre-event strain rate field and a preliminary viscoelastic model to shed light onto the underlying physical processes.

Mantle convection is a fundamental process governing the evolution of our planet. Buoyancies in the mantle induce horizontal and vertical motion of the Earth’s lithosphere, which can be mapped using independent geological datasets. Positive surface deflections induced by mantle convection create erosional/non-depositional environments which lead to gaps (hiatuses) in the stratigraphic record, while negative deflections provide accommodation space for sedimentation to occur. We use continental- and country-scale digital geological maps and regional and local stratigraphic studies at the temporal resolution of geological series (ten to tens of millions of years) to map the distribution of hiatus through geological time. Here we present global continental hiatus surfaces since the Upper Jurassic. We find that they vary inter-regionally at timescales of geological series and that they correlate with known mantle dynamic events. For example, we tend to observe the appearance of a hiatus surface before the arrival of a mantle plume. In Europe, we mapped a large-scale sedimentary hiatus during the Paleocene, prior to the arrival of the Iceland plume. In Africa and South America, we found a widespread absence of the Upper Jurassic prior to the arrival of the Tristan plume. This pattern can be seen as characteristic of plume-induced dynamic uplift. We observe a sea level signal during some geological series, such as in the Oligocene, when there is a global increase of hiatus areas, coinciding with the onset of Antarctic glaciation and associated sea level drop. At other times, we find that the hiatus areas evolve differently for different continents, precluding their interpretation as an eustatic signal. Spectral analysis shows that hiatus surfaces have shorter wavelengths than no hiatus surfaces, requiring higher spherical harmonic degrees to describe the geological series with larger amounts of hiatus. These include the Upper Jurassic, the Paleocene, the Oligocene and the Pleistocene. Our results imply that a key property of time-dependent geodynamic Earth models must be a difference in timescale between mantle convection itself and resulting dynamic topography. Moreover, they highlight the importance of continental-scale compilations of geological data to map the temporal evolution of mantle flow beneath the lithosphere, which can provide powerful constraints for global geodynamic models.

Geodynamicists have long proposed that mantle convection creates dynamic topography — a long-wavelength, low-amplitude signal extending beyond plate tectonics. This predicts transient vertical Earth surface movement of 1–2 km across thousands of horizontal kilometers at any location, including continental interiors. Despite these claims, experts working on local observations, using the multitude of high-resolution geological, sedimentological, and geomorphological data, face challenges in finding clear evidence to unequivocally support dynamic models of whole mantle convection, including the plume mode. Moreover, regional-scale stratigraphic techniques, such as sequence stratigraphy, which enabled hydrocarbon exploration, invoke unconformities on multiple scales but, from their far-field perspective, render correlation to distinct geodynamic events difficult.To circumvent this scaling and correlation problem, I propose to reverse the stratigraphic perspective to an outwards-directed view. This approach requires a theoretical geodynamic framework and the identification of tectonic events (center, near field), such as magmatic arcs, flood basalts, or uplifted domes, followed by outward-directed geological mapping of regional-scale stratigraphic unconformities —predicted by theory— to distal regions. This approach is analogous to the way in which paleoseismologists examine so-called event horizons, i.e., unconformities in the stratigraphic record adjacent to fault scarps that preserve a record of the Earth's surface at the time of earthquake rupture.This event-based stratigraphic mapping method (EVENT-STRAT) enables analysis of geological events on geological maps compiled at regional to continental scales. The technique connects local work into a continent-scale framework, allowing identification of transient patterns related to dynamic mantle-derived events. The EVENT-STRAT mapping method is designed to visualize geological effects resulting from both the plate and the plume mode of mantle convection. The toolbox consists of the hiatus mapping method (Friedrich 2019, Geological Magazine) and the event-based stratigraphic framework mapping (e.g., Friedrich et al. 2018, Gondwana Research). The upcoming EVENT-STRAT mapping method involves multiple polygonal stacking to analyze various stratigraphic event horizons, such as hiatus surfaces and unconformities. The most significant current challenge is to add the high-precision stratigraphic data compiled on local chronostratigraphic charts to continent-scale geological maps. This effort requires the attention of geological surveys on international scales seeking to compile theory-based geodynamic-stratigraphic parameters on the next generation of global and continent-scale geological maps.

The planform is a defining feature of mantle convection. It can be gleaned from the stratigraphic record by mapping the continent-scale distribution of hiatus and no hiatus surfaces serving as a proxy for high and low dynamic topography. We carry this out for all continents apart from Antarctica for eight geological series since the Upper Jurassic, showing that: (i) the planform as indicated by our maps contains wavelengths of the order of 1000 km, smaller than the convective scales implied by the geoid. (ii) The planform changes on timescales of geological series (10-20 Myrs), smaller than the mantle transit time. (iii) Flood basalt eruptions are frequently preceded by hiatus surfaces. (iv) Some hiatus surfaces are not linked to any known plume, potentially reflecting the lateral transport of material in the asthenosphere. Our results reveal the importance of mantle viscosity stratification in shaping the convective planform and the resulting dynamic topography. Geodynamic Earth models should aim to reproduce the global characteristics of our maps, as well as specific regional events identified in this work. Finally, we separate the effects of sea-level variation from regional changes in base level induced by dynamic topography by contrasting the stratigraphic evolution of different regions.

<p>The Victoria microplate is generally assumed to be internally rigid, i.e. non-deforming.  Here, we describe geomorphological evidence for active fragmentation of the microplate along the E-W to NE-SW striking Isuria-Utimbara fault system, Lake Victoria, in the Kenya-Tanzania transboundary region.</p> <p>The Isuria-Utimbara fault system has received little previous attention and is not recognised as seismically active. The fault system marks the northern boundary of the Mara River Basin and lies within the mapped extent of the Victoria microplate, an apparently relatively rigid block situated on the Tanzanian craton. The area is defined by low seismicity within the temporal limits of the instrumental record: seismicity is concentrated along the western arm (as well as, to a lesser extent, the southernmost part of the eastern arm) of the East African Rift (EAR). Here, we describe geomorphological evidence for geologically recent earthquake activity, which has produced scarps and alluvial fans in the hanging walls of the major escarpments. The scarps appear to be segmented, with typical segment lengths of approximately 15 km, and together sum to an along-strike length of approximately 100 km. The height of the scarps exceeds 8 m with a maximum height of 25 m (measured using TanDEM-X Digital Elevation Model (DEM) Global data which has a horizontal resolution of 12 m and an ~2 m height error). Considering the length of a typical segment, scaling relationships suggest the possibility for multiple >M<sub>w</sub> 6 earthquakes. If the segments slipped together, this would result in a maximum earthquake magnitude of >7. Although dating has not yet been carried out, a constraint on slip rate comes from displaced Neogene volcanics found above and below the main escarpment, which give a long-term vertical displacement rate of approximately 0.1mm/yr, comparable with stable continental intraplate settings. Our findings have implications for the seismic hazard of the region: although parts of the Mara River Basin are protected areas of great ecological importance, population density is increasing along the shores of Lake Victoria and a major gold mine lies directly to the south of the fault system. This fault appears to be fragmenting the Tanzanian craton, albeit at relatively slow rates, and cratonic settings are in general capable of producing large and damaging earthquakes due to the possibility for a large seismogenic thickness.</p>

The active tectonics of Anatolia is mostly characterized by its westward motion with respect to Eurasia between the Hellenic subduction in the west and Arabia-Eurasia continental collision in the east. Although most of the deformation is suggested to be confined along Anatolia?s boundary elements, viz. the North and East Anatolian shear zones, recent studies indicate a higher magnitude of internal strain accumulation, especially along the parallel/subparallel strike-slip faults of its central province. We present the first morphochronology-based slip rate estimate for one of these strike-slip structures, the Ovacık Fault, by using cosmogenic 36Cl dating of offset fluvial deposits. At the Köseler Site (39.3643°N, 39.1688°E), two faulted risers, bounding the alluvial fan with its subplanar surface (NF1/NF1?) and the inset terrace tread (NF1/T2), are offset 19?24 and 15?22 m, respectively. The scattered surface ages and variability of 36Cl concentrations in depth profiles suggest strong evidence for inheritance in alluvial fan and terrace deposits; thus, we used modelled depth-profile ages for both surfaces. The modelled ages 8?10 ka for NF1 and 6?8 ka for T2 yield slip-rate estimates 2.4 +0.5/?0.4 mm/a and 2.8 +0.7/?0.7 mm/a, respectively, for the upper-tread reconstruction of the NF1/NF1?and the lower-tread reconstruction of the NF1/T2. Our results together with previous slip-rate estimates for other structures show a significant internal deformation for Anatolia, especially along its subparallel strike-slip faults. These secondary faults slice Anatolia into several pieces giving rise to the formation of the Malatya-Erzincan, Cappadocian, and Central Anatolian slices, where the geometry is strongly controlled by the distribution of the Tethyan accretionary complexes.

<p>In the emergent (subaerial) salt diapirs, the salt faces negative buoyancy when extruded to the surface, and flows outward around their vent by gravity spreading. It also faces dissolution and erosion. Salt supply, salt flow, dissolution, and erosion also influence the diapir’s shape. Although satellite geodesy monitors the surface deformation of the salt-caprock glacier system, the interpretation of the resulting deformation pattern in terms of salt supply, dissolution, and erosion is not straightforward. To overcome these shortcomings, we analyze surface deformation pattern of a fountain-shaped and nearly symmetrical diapir (Finu) within the Zagros Belt of Iran using Persistent Scatterer Interferometry (PSI). The PSI data are extracted from the Sentinel-1 SAR images using the Integrated Wide Area Processor (IWAP) at the German Aerospace Center (DLR) covering four years from October 2014 to December 2018. The line-of-sight signal from the PSI data is decomposed into the vertical and horizontal deformation signals. Within the diapir, the deformation signal is then spatially correlated with the influencing factors, including local position within the diapir, slope, karstification, and drainage. Along an E-W profile across the diapir, two-dimensional deformation vectors reflect salt supply and spreading; therefore, the magnitude and direction of these vectors are influenced by their local position within the diapir and the slope. There is a slight uplift in the central part of the salt domes with active salt extrusion. The deformation vectors divert outward in the slope direction, and the deformation reaches its maximum magnitude at the upper flanks of the central dome. The deformation decreases in the outer flat plateau regions of the extrusions and continues to decrease in the steep slopes at their lateral terminations. Along the same profile, relatively higher subsidence is detected in areas where sinkholes are abundant. In these regions, salt is removed in the subsurface by dissolution-driven karst development in contrast to areas where the surface drainage system is developed, and fluvial erosion is dominant. In the future, a better understanding of the factors controlling salt spreading around the vent and the impacts of dissolution/erosion mechanisms on the deformation will improve our ability to interpret surface deformation of the salt-caprock system at unprecedented spatial and temporal resolution.</p>