Subrosion, i.e. the underground leaching of soluble rocks, causes disastrous sinkhole events worldwide. We investigate the accompanying mass transfer using quarter-yearly time-lapse gravity campaigns over 4 years in the town of Bad Frankenhausen, Germany. After correcting for seasonal soil water content, we find evidence of underground mass loss and attempt to quantify its amount. This is the first study of its kind to prove the feasibility of this approach in an urban area.

Grain size is a key factor for deformation. Quartz is one of the main constituents of the crust, but little is known about grain growth that can change grain size. We therefore experimentally determined grain growth laws for quartz. We discuss the importance of the grain size exponent, water fugacity exponent, and activation energy. Our results indicate that the contribution of grain growth to deformation may become important in lower-crustal conditions.

Deep (> 40 km) seismic reflection surveys are acquired on land along crooked roads. Using the varying azimuth between source and receiver, the true 3-D orientation of crustal structures can be determined. Applying this method to a survey over the ancient Australian Yilgarn Craton reveals that most reflectors in the lower crust exhibit a systematic dip perpendicular to those in the overlying crust, consistent with lateral flow of a weak lower crust in the hotter early Earth 2.7 billion years ago.

Surface processes driven by climate have been linked to the tectonic evolution of mountain belts, with the Himalaya and Asian monsoon being classic examples. Sediments from the Arabian Sea show an increase in erosion from the Karakoram between 17 and 9.5 Ma, followed by an increase in the relative flux from the Himalaya after 5.7 Ma and especially from the Lesser Himalaya after 1.9 Ma. Lack of correlation with climate histories suggests that tectonic forces dominate control over erosion.

Here, we assessed the maturity level and then relative variation of uplift time of three anticlines along the hanging wall of the Zagros Mountain Front Flexure in the Kurdistan Region of Iraq. We also estimated the relative time difference between the uplift time of more mature anticlines and less mature ones to be around 200 kyr via building a landscape evolution model. These enabled us to reconstruct a spatial and temporal evolution of these anticlines.

The Precambrian East European Craton is one of the most important building blocks of the European plate. Unlike in Scandinavia, its crystalline crust in Poland is concealed beneath younger sediments. Reprocessing of ca. 950 km regional reflection seismic profiles acquired during shale gas exploration in NE Poland revealed reflectivity patterns interpreted as signs of Svekofennian orogeny, proving a similar mechanism of Paleoproterozoic crustal formation across the Baltic Sea.

In this work we aim to interpret the extended magnetic low visible at satellite altitudes above central Europe by performing a joint analysis of magnetic field and total gradient intensity maps at low and high altitudes. Here we demonstrate that such a magnetic anomaly is mainly a result of the contrast between two crustal platforms differing strongly in geological and magnetic properties. Synthetic model tests have been created to support our modeling.

Proper magnitude estimates for earthquakes can give insight into the seismic energy released at an earthquake source. This is, in fact, essential for better seismic hazard assessments in tectonically active regions. In the present work, I examine local earthquakes in central Anatolia to estimate their moment magnitudes. The main outcome of this study is an empirical relation that can provide a direct physical quantity of seismic energy in the study region.

Evidence for tidal impacts on volcanism have been gathered by numerous empirical studies. This paper elucidates whether a causal link from the tidal forces to a variation in the volcanic degassing can be traced analytically. We model the response of a simplified magmatic system to the local tidal gravity variations, find that the tide-induced dynamics may significantly alter the bubble coalescence rate, and discuss the consequences for volcanic degassing behaviour.

The Ionian Sea in southern Italy is at the center of active convergence between the Eurasian and African plates, with many known M_w > 7.0 earthquakes. Here, a recently discovered mud volcano (called the Bortoluzzi Mud Volcano or BMV) was surveyed during the Seismofaults 2017 cruise (May 2017). The BMV is the active emergence of crustal fluids probably squeezed up during the seismic cycle. As such, the BMV may potentially be used to track the seismic cycle of active faults.

In order to broaden our knowledge about the deep lithosphere using seismic methods, we develop leading-edge imaging workflows integrating different types of data. Here we exploit the complementary information carried by seismic wavefields, which are fundamentally different in terms of acquisition setting. We cast this information into our processing workflow and build a detailed model of the subduction zone, which is subject to further geological interpretation.

Based on geophysical data integration and 3-D gravity modeling, we show that significant density heterogeneities are expressed as two large high-density bodies in the crust below the Sea of Marmara. The location of these bodies correlates spatially with the bends of the main Marmara fault, indicating that rheological contrasts in the crust may influence the fault kinematics. Our findings may have implications for seismic hazard and risk assessments in the Marmara region.

We documented the role of fluids in the initial embrittlement of the Svecofennian basement and subsequent strain localization and fault evolution at the brittle–ductile transition zone. We studied the fault rocks of a deeply exhumed fault system characterized by mixed brittle–ductile deformation. Results from fluid inclusions, mineral chemistry, and geothermometry of synkinematic minerals document the ingress of distinct fluid batches and fluid pressure oscillations.

The temperature in the crust can be constrained by the Curie depth, which is often interpreted as the 580 °C isotherm. We cast the estimation of Curie depth, from maps of the magnetic anomaly, within a Bayesian framework to properly quantify its uncertainty across the British Isles. We find that uncertainty increases considerably for deeper Curie depths, which demonstrates that generally this method is only reliable in hotter regions, such as Scotland and Northern Ireland.

A large quantity a continental material is transported to the oceans by the world rivers. Once in the ocean, these particles can be transported down the continental shelf thanks to underwater avalanches. The repetition of such massive events can form very important sedimentary deposits at the continent–ocean transition. Data obtained during an oceanic cruise in 2010 allowed us to study such a system located offshore of Gabon and to evaluate the importance sediment transport in this area.

To meet the goal of the Paris Agreement to limit temperature increase below 2 ºC, geologic carbon storage (GCS) will be necessary at the gigatonne scale. But to successfully deploy GCS, seismicity induced by CO₂ injection should be controlled and maintained below a threshold that does not generate nuisances to the population. We conclude that felt induced seismicity can be minimized provided that a proper site characterization, monitoring and pressure management are performed.

Our goal is to better understand the evolution of the Earth's outer shell in northeast Brazil. We analyze the propagation properties (anisotropy) of distant seismic waves in order to look for subsurface, large-scale deformation structures. Results show that structures visible at the surface can be traced down to ~100  km depth, that the imprint of the opening of the Atlantic Ocean can be detected along the coast and that the continental interior is anomalous due to a complex deformation history.

To understand the fate of carbon in subducted oceanic sediments and crust, we studied carbonate phases in rocks from the Mariana subduction zone. These show that carbon is liberated from the downgoing plate at depths less than 20 km. Some of the carbon is subsequently trapped in minerals and likely subducts to greater depths, whereas fluids carry the other part back into the ocean. Our findings imply that shallow subduction zone processes may play an important role in the deep carbon cycle.

Using geological and geophysical data, we set up a 3-D digital description of the underground structure in the central part of the Po alluvial plain. By means of computer-simulated propagation of seismic waves, we were able to identify the structural features that caused the unexpected elongation and amplification of the earthquake ground motion that was observed in the area during the 2012 seismic crisis. The study permits a deeper understanding of the seismic hazard in alluvial basins.

When carbon dioxide is introduced into the subsurface it will migrate upwards and can encounter faults, which, depending on their hydrogeological properties and composition, can form barriers or pathways for the migrating fluid. We analyse uncertainties associated with these properties in order to better understand the implications for the retention of CO₂ in the subsurface. We show that faults that form seals for other fluids may not be seals for CO₂, which has implications for storage sites.

This study investigates approaches to implementing plate boundaries within a fluid dynamic framework, targeted at the evolution of subduction over many millions of years.

Ancient evaporite sequences were deposited as interlayered rocksalt, other evaporites, and non-evaporite rocks that have enormous differences in strength. Whereas the ductile layers flow during deformation, strong layers are folded and/or torn apart, with the intrasalt deformation dependent on the mode and history of salt tectonics. This has important implications for accurately imaging and interpreting subsurface seismic data and for drilling wells through evaporite sequences.