Data acquisition costs mainly borne by expensive vibrator machines (i.e., deployment, operations, and maintenance) can be regarded as the main impediment to wide application of seismic methods in the mining industry. Here, we show that drill bit noise can be used to image the shallow subsurface when it is optimally acquired and processed. Drill bit imaging methods have many applications in small scale near-surface projects, such as those in mining exploration and geotechnical investigation.

Shear zones dominated by hydrated mantle rocks (serpentinites) occur in many tectonic settings around the world. To better understand the internal structure, composition and possible mechanical behaviour of these shear zones, we performed a detailed field, petrological and microanalytical study of the Livingstone Fault in New Zealand. We propose a conceptual model to account for the main physical and chemical processes that control deformation in large serpentinite shear zones.

Seismic reflection data allow us to infer subsurface structures such as horizon and fault surfaces. The interpretation of this indirect data source is inherently uncertainty, and our work takes a first look at the scope of uncertainties involved in the interpretation of 3-D seismic data. We show how uncertainties of fault interpretations can be related to data quality and discuss the implications for the 3-D modeling of subsurface structures derived from 3-D seismic data.

This work was inspired by an effort to numerically reproduce laboratory models of extension tectonics. We tested various set-ups to find a suitable analogue model and in the process systematically charted the impact of set-ups and boundary conditions on model results, a topic poorly described in existing scientific literature. We hope that our model results and the discussion on which specific tectonic settings they could represent may serve as a guide for future (analogue) modeling studies.

Subduction-transform edge propagator (STEP) faults are the locus of continual lithospheric tearing at the edges of subducted slabs, resulting in sharp changes in the lithospheric thickness and triggering lateral and/or near-vertical mantle flow. Here, we study upper mantle rocks recovered from a STEP fault context by < 4 Ma alkali volcanism. We reconstruct how the microstructure developed during deformation and coupled melt–rock interaction, which are promoted by lithospheric tearing at depth.

Image correlation techniques have provided new ways to analyse the distribution in space and time of deformation in analogue models of tectonics. Here, we demonstrate how the correlation of successive time-lapse images of a deforming model allows calculating the finite displacements and finite strain tensor. We illustrate, using synthetic images, the ability of the algorithm to produce maps of the finite deformation.

We propose innovative parametric modeling allowing for analysis of a very large number of fault-slip numerical simulations on 3-D discrete fault network. The approach allows for the first time producing failure envelopes of large rock volumes containing faults, using variations of geological conditions such as remote stresses, cohesion, friction, and fluid pressure. This tool helps to define the most conservative fault slip hazard case or to account for potential uncertainties in the input data.

In projects based on enhanced geothermal system (EGS) technology, knowledge of the in situ stress state is of central importance to predict the response of the rock mass to different stimulation programs. We propose a characterization of the in situ stress state from the analysis of ultrasonic borehole imager (UBI) data acquired at different key moments of the reservoir. We discuss a significant stress rotation at depth and the absence of a significant change in the stress magnitude.

We present an updated geological map of the volcanic rocks present in the north-east Oman mountains. These volcanic rocks erupted at the seafloor, probably above a young subduction zone, and have since been tectonically transported into their accessible position. The updated map allows us to examine the spatial relationships between the different volcanic and geological features, including copper, gold, and chrome deposits. The new map will aid further study in Oman and other similar settings.

A 2-D numerical modelling approach to simulate the mechanical formation of sinkhole cluster inside large-scale karstic depressions is presented. Different multiple cavity growth scenarios at depth are compared regarding the mechanical process and collapse style. The outcomes of the models are compared to results from remote sensing and geophysics for an active sinkhole area in the Dead Sea region.

The formation of dolomite (CaMg(CO₃)₂), an abundant mineral in Earth's geological record, is still incompletely understood. We studied dolomites embedded in a 100 m thick succession of coastal alluvial clays of Triassic age in the southern Alps. Observation by light microscopy and Sr isotopes suggests that dolomites may spontaneously from concentrated evaporating seawater, in coastal ephemeral lakes or tidal flats along the western margin of the Triassic Tethys sea.

3-D seismic reflection data reveal that deepwater volcanoes have rugged basal contacts, which truncate underlying strata, and erupted lava flows that feed lobate lava fans. The lava flows (>  9 km long) account for 50–97 % of the total erupted volume. This indicates that deepwater volcanic edifices may thus form a minor component (~ 3–50 %) of the extrusive system and that accurate estimates of erupted volume require knowledge of the basal surface of genetically related lava flows.

Salt basins are important as they bear abundant natural resources and record valuable geological information. However, some models of salt basin evolution do not fully reconcile with natural examples. Using state-of-the-art analogue modelling, we investigate how a relatively stable area, the translational domain, occurs and gets overprinted in salt basins. The results suggest that that variation of sediment deposition is the key factor for overprinting the translational domain.

Earthquakes in the subsurface are hard to monitor due to their complicated signals. We aim to make the monitoring of the subsurface possible by redatuming the sources and the receivers from the surface of the Earth to the subsurface to monitor earthquakes originating from small faults in the subsurface. By using several sources together, we create complex earthquake signals for large-scale faults sources.

We quantify the effects that 3-D fractures with realistic distributions of aperture have on seismic wave attenuation and velocity dispersion. Attenuation and dispersion are caused by fluid pressure diffusion between the fractures and the porous background. We show that (i) both an increase in the density of contact areas and a decrease in their correlation length reduce attenuation and (ii) a simple planar fracture can be used to emulate the seismic response of realistic fracture models.

New acquisition styles for active seismic source exploration provide a wealth of additional quasi-passive data. We show how these data can be used to gain complementary information about the subsurface. Specifically, we process an active-source dataset from an alpine valley in western Colorado with both active and passive inversion schemes. The results provide new insights on subsurface hydrology based on the ratio of P-wave and S-wave velocity structures.

The dolomitized intervals of the Lower Jurassic deposits exposed in the Montagna dei Fiori Anticline (Central Apennines, Italy) have been investigated. Accordingly, two fault-related dolomitization events were recognised and interpreted as having occurred before and during the Apenninic orogeny. The analyses suggest significant involvement of evaporitic fluids in both events, most likely derived from the underlying Upper Triassic Burano Formation in the detachment level.

Griffith (1921) assumed that energy used to create new surface area by breaking intact rock immediately becomes surface energy which is not available for further breakage. Our lab data disprove this assumption; we created much more new surface area, 90 % on submicron fragments, than the energy involved should allow. As technology allows ever smaller fragments to be measured, continued use of the Griffith assumption will lead to incorrect energy budgets for earthquakes and rock avalanches.

The point cloud of located aftershocks contains the information which can directly reveal the fault geometry and temporal evolution of an earthquake sequence. However, there is a lack of studies using state-of-the-art visual analytics methods to explore the data to discover hidden information about the earthquake fault. We present a novel interactive approach to illustrate 3-D aftershock point clouds, which can help the seismologist to better understand the complex fault system.

The prevalent assumption in solid Earth science is that if we have different lithologies in the mantle they are separately in chemical equilibrium and together in chemical disequilibrium; this is the condition that at the moment defines a chemically heterogeneous mantle. The main contribution of this study is to show that this may not be the case. We can have (partial) chemical equilibration between the two and still observe a chemically heterogeneous mantle.

The Fuego de Colima volcano (Mexico) shows a complex eruptive history, with periods of rapid and slow lava dome growth punctuated by explosive activity. Here we reconstructed the 1998–2018 average discharge rate by means of satellite thermal data and the literature. Using spectral and wavelet analysis, we found a multi-term cyclic behavior that is in good agreement with numerical modeling, accounting for a variable magmatic feeding system composed of a single or double magma chamber system.

The fall of the Dead Sea level since the 1960s has provoked the formation of over 6000 sinkholes, a major hazard to local economy and infrastructure. In this context, we study the evolution of subsidence phenomena at three area scales at the Dead Sea’s eastern shore from 1967–2017. Our results yield the most detailed insights to date into the spatio-temporal development of sinkholes and larger depressions (uvalas) in an evaporite karst setting and emphasize a link to the falling Dead Sea level.