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Seasonal deformation of mountain rock slopes can be driven by groundwater infiltration and depletion. Such processes could explain our field observation in the Aletsch Valley, Switzerland, where GNSS‐derived 3D annual displacement amplitudes reach 3.4 cm. However, the physical mechanisms behind such groundwater‐driven surface displacements are not well understood. Here, we develop a fully coupled hydromechanical model to simulate the relevant processes in a valley slope embedded with numerous fractures of variable sizes. The magnitude and orientation of transient annual slope surface displacement obtained from our model are in overall agreement with the field observations. The key geological factors controlling the type and magnitude of reversible mountain slope deformations are fracture network geometry, fracture aperture, and regional stress field. We show that the heterogeneity and anisotropy of bedrock hydromechanical responses, originating from depth‐dependent variations of fracture properties, play a critical role in groundwater recharge and valley slope deformation. During recharge events, pore pressure perturbations migrate downward from the groundwater table and toward the receiving stream and the deep subsurface. This process driven by pressure diffusion and poroelastic stressing develops in the subsurface with a great reach of up to a few kilometers, called critical hydromechanical response zone, and controls surface deformation patterns. During groundwater recession, this hydromechanical response zone expands downward and ground surface displacement vectors rotate upwards. Our results suggest that slope surface deformation can inform about subsurface permeability structures and pore pressure fluctuations, which have important implications for understanding groundwater flow in fractured bedrock slopes. Groundwater recharge in alpine valleys mainly occurs during snowmelt and/or rainstorm events. When recharge raises groundwater table in the slope, the bedrock can deform, and centimeter‐scale surface displacements can be observed. Here, we model this process in an alpine valley and investigate how bedrock fractures and regional stresses affect the surface displacement pattern. We show that slope surface deformation is controlled by a so‐called hydromechanical response zone reaching up to a few kilometers below the valley ridges. The shape and location of this zone change throughout the year. We compare our modeling results with long‐term deformation records from the lower Aletsch Valley, Switzerland, and show that they are in general agreement. The results of this work and insights obtained advance our fundamental understanding of the mechanisms of groundwater‐driven deformations in fractured rock slopes. Our research opens an avenue to use the information of surface deformation patterns to infer subsurface hydrogeological processes. Coupled hydromechanical simulations are compared to surface displacement magnitude, orientation and hysteresis observed at Aletsch, SwitzerlandGroundwater recharge‐related pressure diffusion and poroelastic stressing in subsurface rock drive slope surface displacementCentimeter‐scale slope surface displacements occur in fractured crystalline rock with permeability in the narrow range of 10−16–10−14m2 Coupled hydromechanical simulations are compared to surface displacement magnitude, orientation and hysteresis observed at Aletsch, Switzerland Groundwater recharge‐related pressure diffusion and poroelastic stressing in subsurface rock drive slope surface displacement Centimeter‐scale slope surface displacements occur in fractured crystalline rock with permeability in the narrow range of 10−16–10−14m2

A comprehensive worldwide permeability data set has been compiled consisting of 29,000 in situ permeabilities from 221 publications and reports and delineating the permeability distribution in crystalline rocks into depths of 2000 meters below ground surface (mbgs). We analyze the influence of technical factors (measurement method, scale effects, preferential sampling, and hydraulic anisotropy) and geological factors (lithology, current stress regime, current seismotectonic activity, and long-term tectonogeological history) on the permeability distribution with depth, by using regression analysis and k-means clustering. The influence of preferential sampling and hydraulic anisotropy are negligible. A scale dependency is observed based on calculated rock test volumes equaling 0.6 orders of magnitude of permeability change per order of magnitude of rock volume tested. Based on the entire data set, permeability decreases as log(k) = -1.5 × log(z) - 16.3 with permeability k(m2) and positively increasing depth z(km), and depth is the main factor driving the permeability distribution. The permeability variance is about 2 orders of magnitude at all depths, presumably representing permeability variations around brittle fault zones. Permeability and specific yield/storage exhibit similar depth trends. While in the upper 200 mbgs fracture flow varies between confined and unconfined, we observe confined fracture and matrix flow below about 600 mbgs depth. The most important geological factors are current seismotectonic activity (determined by peak ground acceleration) and long-term tectonogeological history (determined by geological province). The impact of lithology is less important. Based on the regression coefficients derived for all the geological key factors, permeability ranges of crystalline rocks at site scale can be predicted. First tests with independent data sets are promising. Crustal kin crystalline rock to 2000 mbgs decreases with log(k)?=?-?1.5 × log(z)?-?16.3as inferred from a database of 30,000 in situ k-estimationsDepth, current seismotectonic activity, and tectonogeological history are the most important geological factors controlling kdistributionNew regression models allow to predict depth-dependent site scale permeability distribution

An outstanding legacy data set has been compiled from underground excavations mostly prospected and mined by the former Soviet (German) Stock Company Wismut describing the hydrology of faulted basement rocks in the Ore Mountains (SE Germany). It consists of more than 5000 detailed descriptions of groundwater inflows to about 660?km of tunnels and 57?km of drillings measured during or shortly after excavation. Inflow measurements (recorded between 1E-8 and 4E-2?m3/s) have been converted to fracture transmissivities using a simplified analytical solution. Discarding site specific effects, the median log transmissivity decreases from 1E-7 to 1E-10?m2/s within the studied depth interval of 0–2000?meters below ground surface (mbgs), and the spacing of conductive fracture increases from 0.1 to 2500?m. This general trend is overprinted at three mining sites by a clear reversal of fracture transmissivity which correlates with contact metamorphic aureoles around Variscan granite intrusions (327–295?Ma). We hypothesize that this transmissivity increase is caused by processes accompanying granite intrusion and contact metamorphism. The thickness of these hydraulically active aureoles is greater in lower-grade metamorphic schist than in higher-grade metamorphic gneisses. Rock mass equivalent continuum conductivities have been estimated by arithmetic averaging of fracture and matrix transmissivities over 100?m intervals and have been converted to permeabilities. The median equivalent continuum permeability decreases with depth according to log(k)?=?-?1.7?*?log(z)?-?17.3 (kin m2and increasing depth zin kilometer being positive). Matrix conductivity controls the bulk conductivity below about 1000?mbgs and is less sensitive to the occurrence of contact metamorphic aureoles. A Q database (1E-8 to 4E-2?m3/s) compiled from underground excavations consisting of >5000 inflows to about 700?km of drifts and boreholesFracture T(3E-13 to 2E-4?m2/s) in up to 2000?mbgs are increased in aureoles around Variscan intrusions; the extent depends on the lithologyEquivalent rock mass K(3E-15 to 6E-6?m/s) or kdecreases and conductive fracture spacing increases log-log linearly with depth

Moisture variation has been noted as a driver of strains in both natural and anthropogenic bedrock environments. Similarly, increasing water content has been shown to reduce elastic stiffness in a variety of rock materials, though evidence for granites is limited. This study presents strains of an axially stressed (0.1 MPa) Herrnholz granite cylinder with ambient relative humidity alternating between 20% and 90% in a stepwise manner. At each ambient humidity level, the Young's modulus and Poisson's ratio were determined by performing a series of load and unload cycles at 1–12 hr intervals. We observed that when the ambient humidity increased from 20% to 90%, Young's modulus declined by 13% on average, and nearly returned to the initial dry value when the ambient humidity was reduced to 20%. Poisson's ratio increased by 130% in response to the same humidity change, and approximately 60% of it was reversed when dried. These changes occurred linearly with a volumetric strain of up to 8 × 10−4of the tested sample, equivalent to 24.5 MPa internal stress. This stress change is attributed to the generation of nanoscale adsorption stress, which includes surface adhesion pressure along pore walls and capillary pressures within characteristic pore spaces. Using a modified adsorption model, the two contributions were estimated to be 8.5 and 16 MPa, respectively. The agreement between laboratory‐derived and modeled stress change validates the proposed mechanism of adsorption‐induced strains and elastic property variations in unweathered granite. The public is well aware that moisture variations caused by rainfall events or freeze‐thaw processes have a negative impact on the stability of rock‐formed infrastructures, such as stone constructions, water supplies, bridges, and natural rock slopes. However, the underlying mechanisms, such as how liquid water or vapor affects the properties and behaviors of rock, are not well understood. Granite, in particular, is generally known as a hard, low‐porosity, and clay‐deficient material; however, its softening and expansion under moist conditions is underappreciated. In a stepwise manner, we measured progressive deformation, and changes in Young's modulus and Poisson's ratio of a Herrnholz granite cylinder with ambient humidity alternating between 20% and 90%. Results suggest softening (Young's modulus) and volumetric expansion of unweathered granite in wet conditions, and vice versa in dry conditions. An increase in ambient humidity from 20% to 90% results in a decrease of Young's modulus by 13%, increase of Poisson's ratio by 130%, and volumetric expansion of 8.4 × 10−4, of an unweathered Herrnholz granite cylinderThe bulk modulus of the tested sample varies linearly with volumetric expansion as relative humidity increasesThe variations in strains and elastic properties are associated with the physical process of adsorption An increase in ambient humidity from 20% to 90% results in a decrease of Young's modulus by 13%, increase of Poisson's ratio by 130%, and volumetric expansion of 8.4 × 10−4, of an unweathered Herrnholz granite cylinder The bulk modulus of the tested sample varies linearly with volumetric expansion as relative humidity increases The variations in strains and elastic properties are associated with the physical process of adsorption

Dry granular flows are ubiquitous, yet poorly understood mass wasting features on the Moon. Above all, their global distribution, relation to the physical environment, and drivers are poorly understood. Here, we build and deploy a convolutional neural network and map 28,101 flow features between 60°N and S by scanning through ∼150,000 Lunar Reconnaissance Orbiter images. We observe that flows are heterogeneously distributed over the Moon, where all major hotspots are located in craters and almost all hotspots are located in the nearside maria. We further observe that younger surfaces feature higher flow feature densities, while pre‐Nectarian terranes can still host flows, remaining subject to active erosion billions of years after their formation. Our observations suggest that impacts at various scales have been—and likely still are—acting as the main, global‐scale, long‐ and short‐term driver of flow occurrence, strongly influenced by the properties of the target rock material. Lunar granular flows are dry mass movements that have been identified in a few regions of the Moon. As of today little is known about these features: How many are there? Where are the majority of these features located? What is driving their occurrence? Here, we build and use a convolutional neural network to automatically and rapidly process a stack of ∼150,000 lunar satellite images. Our network is able to identify 28,101 flow features, which appear to be predominantly located in craters and nearside maria, as well as in very young and very old surfaces. Our observations indicate that impacts have been—and likely still are—the main driver of granular flow feature occurrence, in connection with the properties of the target material. We mapped 28,101 granular flow features between 60°N and S using a neural networkDense flow feature hotspots are predominantly located in (a) craters, (b) on the lunar nearside, (c) in the lunar mariaFlow feature occurrence is mainly controlled by impacts, where the target rock properties and terrane age appear to play an important role We mapped 28,101 granular flow features between 60°N and S using a neural network Dense flow feature hotspots are predominantly located in (a) craters, (b) on the lunar nearside, (c) in the lunar maria Flow feature occurrence is mainly controlled by impacts, where the target rock properties and terrane age appear to play an important role

The epidermal growth factor receptor (EGFR) is dysregulated in various tumour types such as glioblastoma multiforme (GBM), breast cancer, ovarian carcinoma, non-small cell lung cancer and other cancers. As the intracellular tyrosine kinase of the EGFR activates signalling cascades leading to cell proliferation, angiogenesis and inhibition of apoptosis, the EGFR represents an attractive target in cancer therapy. In GBM which is the most common primary central nervous system tumour in adults, the EGFR is overexpressed in about 40 to 50 of cases, and almost half of these co-express the mutant receptor subtype EGFRvIII. This EGFR variant is constitutively activated, and thereby may contribute to the aggressive and refractory course of GBM which is associated with a median survival of only 40 to 60 weeks from diagnosis. Various trials are ongoing focusing on EGFR and EGFRvIII as new therapeutic targets in GBM. Anti-EGFR monoclonal antibodies (MAbs), e.g. cetuximab, and tyrosine kinase inhibitors (TKIs), e.g. erlotinib and gefitinib, are the most advanced in clinical development. Several trials are investigating MAbs or TKIs in combination with other agents such as inhibitors of the mammalian target of rapamycin. Other still preliminary approaches targeting the EGFR are small interfering RNA, antisense RNA and ribozymes, which lead to degradation of EGFR mRNA. Further studies are needed to define their clinical potential, to identify biological predictors of response and thus to characterize subgroups of patients who will benefit from treatment with these new agents.

A comprehensive surface displacement monitoring system installed in the recently deglaciated bedrock slopes of the Aletsch Valley shows systematic reversible motions at the annual scale. We explore potential drivers for this deformation signal and demonstrate that the main driver is pore pressure changes of groundwater in fractured granitic mountain slopes. The spatial pattern of these reversible annual deformations shows similar magnitudes and orientations for adjacent monitoring points, leading to the hypothesis that the annually reversible deformation is caused by slope‐scale groundwater elevation changes and rock mass properties. Conversely, we show that the ground reaction to infiltration from snowmelt and summer rainstorms can be highly heterogeneous at local scale, and that brittle‐ductile fault zones are key features for the groundwater pressure‐related rock mass deformations. We also observe irreversible long‐term trends (over the 6.5 years data set) of deformation in the Aletsch valley composed of a larger uplift than observed at our reference GNSS station in the Rhone valley, and horizontal displacements of the slopes towards the valley. These observations can be attributed respectively to the elastic bedrock rebound in response to current glacier mass downwasting of the Great Aletsch Glacier and gravitational slope deformations enabled by cyclic groundwater pressure‐related rock mass fatigue in the fractured rock slopes. Mountain ranges are subject to deformation due to tectonic forces, orogenesis, erosion, and gravity. Other factors can deform the slopes, such as atmospheric‐driven thermal expansion and contraction, freeze‐thaw in open fractures, and pore pressure variations. Close to retreating glaciers, the mechanical unloading of the ice body, and rapidly changing thermal and hydrologic conditions lead to deformation of the slopes. The difficulty resides in identifying the different factors contributing to the total deformation. We track surface displacements of fractured crystalline rock slopes adjacent to the Great Aletsch Glacier (Switzerland) tongue for more than six years at unprecedentedly high spatial and temporal resolutions. Our results demonstrate that groundwater is a critical driver of deformation. Centimetric reversible outward displacements are observed after the snowmelt season each year, followed by a seasonal recession to which are superimposed displacements caused by heavy rainfall‐recharge events. Fault zones can be key features where most of the hydromechanical deformation occurs, and their geometry can control the direction of deformation. Glacier melting induces long‐term trends of deformation. In addition, annual pore‐pressure cycles lead to hydromechanical fatigue processes. This work opens a new vision on the spatial and temporal variability of processes responsible for bedrock deformation in paraglacial mountain slopes. Seasonal pore pressure variations in fractured crystalline hillslope induce correlated reversible surface deformationsDecameter‐scale brittle‐ductile faults control local spatial variations of deformation patternsCyclic groundwater pressure‐related rock mass fatigue induces irreversible gravitationally driven displacements in valley slopes Seasonal pore pressure variations in fractured crystalline hillslope induce correlated reversible surface deformations Decameter‐scale brittle‐ductile faults control local spatial variations of deformation patterns Cyclic groundwater pressure‐related rock mass fatigue induces irreversible gravitationally driven displacements in valley slopes

: Vertical settlements with magnitudes reaching 12 cm were measured in fractured crystalline rock several hundred metres above the Gotthard highway tunnel in central Switzerland. Such magnitudes of surface subsidence were unexpected, especially in granitic gneisses and appear to be related to large-scale consolidation of fractures resulting from fluid drainage and pore pressure changes following tunnel construction. This paper focuses on the mechanisms involved in the development of such surface displacements and presents the preliminary results of 2-D discontinuum (i.e. distinct-element) and 2-D continuum modelling (i.e. finite-element). Results show that settlements are most sensitive to horizontal joints, as would be expected, but that vertical fractures also contribute to the settlement profile through a 'Poisson ratio' effect. However, these models also suggest that fracture deformation alone cannot explain the total subsidence measured. As such, 2-D poro-elastic finite-element models are presented to demonstrate the contributing effect of consolidation of the intact rock matrix.

Summary ¶Rock zones containing a high fracture density and/or soft, low cohesion materials can be highly problematic when encountered during tunnel excavation. For example in the eastern Aar massif of central Switzerland, experiences during the construction of the Gotthard highway tunnel showed that heavily fractured areas within shear zones were responsible for overbreaks in the form of chimneys several metres in height. To understand and estimate the impact of the shear zones on rock mass behaviour, knowledge concerning the rock mass strength and deformation characteristics is fundamental. A series of laboratory triaxial tests, performed on samples from granite- and gneiss-hosted shear zones revealed that with increasing degree of tectonic overprint, sample strength decreases and rock behaviour shows a transition from brittle to ductile deformation. These trends may be explained by increasing fracture densities, increasing foliation intensity, increasing thickness of fine-grained, low cohesion fracture infill, and increasing mica content associated with the increasing degree of tectonic overprint. As fracture density increases and the influence of discrete, persistent discontinuities on rock mass strength decreases, behaviour of the test samples becomes more and more representative of rock mass behaviour, i.e. that of a densely fractured continuum. For the purpose of numerical modeling calculations, the shear zones may be subdivided with respect to an increasing fracture density, foliation intensity and mica content into a strongly foliated zone, a fractured zone and a cohesionless zone, which in turn exhibit brittle, brittle-ductile and ductile rock mass constitutive behaviour, respectively.

The long‐ and short‐term drivers and transport mechanisms of lunar rockfalls are currently not well understood, but could provide valuable information about the geologic processes that still shape the surface of the Moon today. Here, we compare the global distribution of rockfalls with relevant geophysical data, such as seismic, topographic, thermal, gravity anomaly, and tidal displacement data sets. Rockfalls appear to predominantly occur (a) on equator‐facing slopes and thus in regions with large thermal amplitudes, (b) on slope angles well above‐average (Δ ∼ 10°), and (c) in regions with above‐average rock abundance. We do not observe a qualitatively or statistically relevant relation between rockfall abundance, monitored Apollo‐era shallow seismic activity, and the distribution of visible tectogenetic features. Informed by our global analysis, we conduct a targeted, in‐depth study of 687 rockfall boulders and trajectories in 13 sites across the Moon, including 7 craters, 2 volcanic vents, 2 tectonic structures, and 2 unclassified geomorphic regions. We identify four different source region types, where the type appears to control the occurrence of rockfalls. The source region type in turn is controlled by surface age rather than geomorphic context. We find that rockfall trajectories are mainly controlled by the trigger energy and the geometry of the slope. Our results suggest that erratic small‐scale impacts (mainly in old, Imbrian‐Nectarian, shallow terranes), aided by solar‐induced thermal fatigue of fractured bedrock (mainly in young, Copernican‐Eratosthenian steep terranes), were the dominant, global‐scale long‐ and short‐term drivers of rockfalls in the Moon's recent geologic past. The processes that drive rockfall occurrence are largely unknown, but could provide valuable information about the past and current evolution of the Moon's surface and interior. We compare the global distribution of rockfalls with a series of maps, such as seismic, topographic, thermal, and gravity anomaly maps and observe that rockfalls mainly occur (a) on equator‐facing slopes and thus in regions with large temperature differences, (b) on slope angles above‐average, and (c) in regions with rocky surfaces. We do not observe a relation between rockfall abundance, Apollo‐era seismic activity, and the distribution of visible tectonic features. Informed by our global‐scale analysis we study 687 rockfalls in 13 sites of interest in greater detail, including volcanic‐, tectonic‐, and impact‐related geomorphic regions. We observe that the source region type appears to control rockfall occurrence, which in turn is controlled by the surface age. We find that the lunar rockfall transport process appears to be mainly controlled by the driver energy and the steepness of the slope. Our results suggest that small‐scale impacts (mainly in old, shallow regions) and solar‐driven thermal breakdown of fractured bedrock (mainly in young, steep regions) were the main, global‐scale drivers of rockfalls in the Moon's recent geologic past. We study the drivers and transport mechanisms of lunar rockfalls on a local and global scaleThe two dominant, global‐scale rockfall drivers appear to be: (a) impacts and (b) solar‐driven thermal fatigueThe rockfall driver depends on the source region age and type rather than the geomorphic context We study the drivers and transport mechanisms of lunar rockfalls on a local and global scale The two dominant, global‐scale rockfall drivers appear to be: (a) impacts and (b) solar‐driven thermal fatigue The rockfall driver depends on the source region age and type rather than the geomorphic context

A singlet oxygen determination method based on the formation of dimethyl-(2,5)-2-methoxy-5-hydroperoxydihydrofuran (DMFO2) followed by acid hydrolysis with 0.1 N H2SO4is described. Hydrogen peroxide is formed thereby as a product of hydrolysis which is then determined by the horseradish peroxidase-catalyzed formation of the homovanillic acid dimer. Since DMFO2is a crystalline compound with sufficient stability it can be used as a primary standard for the determination. The peroxidase-catalyzed hydrogen peroxide determination allows detection of singlet oxygen concentrations as low as 10−7M.

Cross‐hole fluid injection tests were performed on shallow (0.5 km depth) crustal fault zones to characterize their internal flow structures on scales of 3–30 m. The data were acquired at the Grimsel Rock Laboratory, Switzerland, after the zonal isolation of damage zones in boreholes equipped with multipacker systems. We show that 80% of the pressure responses detected evolved as a power function of time due to fracture‐controlled flow and were best described by a fractional model with a flow dimension (n) in the range of [1.3,1.5]. The scaling of characteristic times (tc) and intermediate transitions in the flow dimension is shown to be inconsistent with the trend expected for normal diffusion, indicating a diffusion slowdown process caused by the spatial integration of structurally different damage zones. An analysis of the entire data set points to a subdiffusive regime where the mean squared displacement of pressure fronts, ⟨r2(t)⟩, scales as ⟨r2(t)⟩∝t0.59, similar to an anomalous diffusion process on synthetic fractal systems. We characterize this diffusion slowdown by calculating a network connectivity exponent (θ) of 1.4, from which we estimate a fractal dimension of df=2.23 for the tested fault zones. Such a value close to 2.0 supports the view of fault damage zones as hierarchical systems promoting flow channeling. Our results provide further support to theoretical models of fractional flow and their application to fractured media in nature. We report direct, high‐resolution observations of pressure diffusion from fluid injection tests in shallow crustal fault zonesFractional flow regimes systematically emerge in response to spatial integration of structurally different damage zones during injectionThe fractal structure of damage zones may explain the emergence of anomalously slow pressure diffusion around faults

New in situ measurements to constrain the range, distribution, and spatial (meter‐scale) variations of permeability in shallow crustal fault zones are reported based on systematic downhole tests at 0.5‐km depth in crystalline rock. Single and cross‐hole hydraulic packer tests were performed at a new dedicated test facility hosted in the Grimsel Test Site, in the Swiss Alps, following the technical instrumentation and isolation of discrete fault zones accessed by an array of boreholes. Single‐hole test results are presented in this paper, while cross‐hole experiments are reported in the companion paper. Our results reveal a sharp spatial falloff in permeability, from 10‐13to 10‐21m2, with off‐fault distances of 1–5 m and characterized by a power‐law relation with fracture density. Fractures linking subparallel faults were detected as high‐permeability discrete spots several meters away from off‐fault damage. Due to the narrow (centimeter‐wide) thickness of fault cores, the hydraulic tests presented in this study do not characterize the permeability of fault core materials. The transmissivity of single fractures spans six orders of magnitude (10‐12to 10‐6m2/s) and is systematically higher in damage zones. In situ stresses appear to have a minor effect on natural, present‐day fracture transmissivity at the borehole scale. We suggest that the geometrical and topological properties of fracture systems instead tend to control the permeability of the shallow crustal faults studied. We mapped permeability variations across shallow crustal fault zones through systematic downhole pressure pulse testsA sharp permeability decay up to eight orders of magnitude with off‐fault distance is observedGeometry and topology exert a dominant control on the permeability of fracture systems in shallow crustal settings

We monitored the seismohydromechanical rock mass response to high‐pressure fluid injection during a decameter‐scale hydraulic stimulation experiment in crystalline rock at the Grimsel Test Site, Switzerland. Time series recorded at two pressure monitoring locations show abrupt pressure increases that change in amplitude and appearance between subsequent stimulation cycles. Induced seismicity correlates with the propagation of one of these pressure fronts. Deformation data along the same shear zone shows permanent fracture dislocation preceded by strong transient fracture opening. We interpret these observations as nonlinear pressure diffusion along flow channels that reorganize in response to hydromechanical effects during stimulation. Combining these observations with the in situ stress field estimated before stimulation, we argue that the underlying hydromechanical processes involve mixed‐mode stimulation with both Mode I and II/III fracture dislocation. Hydraulic shearing of preexisting fractures and hydraulic fracturing are commonly used to enhance the hydraulic conductivity and connectivity within in situ fracture networks, for example, in the framework of geothermal heat exploitation. Both treatments are based on high‐pressure fluid injections that induce deformation in the overall rock mass and dislocations along the fractures therein. It was previously observed that characteristic responses of both treatments can appear simultaneously during high‐pressure fluid injection. It is beneficial to locally resolve the different response behaviors in the rock mass, as they yield different connectivity enhancements. During a 20‐m‐scale stimulation experiment, we observed pressure signals within the target rock mass indicative of both shearing and fracturing behavior. These signals were monitored at ~7 m distance to injection location. The aseismic/seismic character of these pressure signals is in agreement with the different response behavior. Including previously conducted in situ stress characterization data, we argue that our experiment provides insight into the simultaneous occurrence of shearing and fracturing behavior. The results of this study are important for the interpretation of reservoir‐scale stimulation experiments and predictive numerical modeling of rock mass responses to high‐pressure fluid injections. Behavior of directly monitored high‐pressure pulses indicates nonlinear diffusion induced by fracture dilationHigh fracture fluid pressure signals change direction during stimulation and are associated with seismic and aseismic deformationSeismohydromechanical monitoring indicates a combination of Mode I and II/III deformation during high‐pressure fluid injections