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Stress Map of Great Britain and Ireland 2022

Stress maps show the orientation of the current maximum horizontal stress (SHmax) in the earth's crust. Assuming that the vertical stress (SV) is a principal stress, SHmax defines the orientation of the 3D stress tensor; the minimum horizontal stress Shmin is than perpendicular to SHmax. In stress maps SHmax orientations are represented as lines of different lengths. The length of the line is a measure of the quality of data and the symbol shows the stress indicator and the color the stress regime. The stress data are freely available and part of the World Stress Map (WSM) project. For more information about the data and criteria of data analysis and quality mapping are plotted along the WSM website at http://www.world-stress-map.org. The stress map of Great Britain and Ireland 2022 is based on the WSM database release 2016. All data records have been checked and we added a number of new data from earthquake focal mechanisms from the national earthquake catalog and borehole data. The number of data records has increased from n=377 in the WSM 2016 to n=474 in this map. Some locations and assigned quality of WSM 2016 data were corrected due to new information. The digital version of the map is a layered pdf generated with GMT (Wessel et al., 2019) using the topography of Tozer et al. (2019). We also provide on a regular 0.1° grid values of the mean SHmax orientation which have a standard deviation < 25°. The mean SHmax orientation is estimated using the tool stress2grid of Ziegler and Heidbach (2019). For this estimation we used only data records with A-C quality and applied weights according to data quality and distance to the grid points. The stress map is available at the landing page of the GFZ Data Services at http://doi.org/10.5880/WSM.GreatBritainIreland2022 where further information is provided.

Mineral Chemistry of Metapelites from the Modereck Nappe (central Tauern Window, Eastern Alps)

In this dataset we report exemplary, representative mineral chemistry data of two metapelite samples (PG61 and PG89) from the Modereck Nappe in the central Tauern Window. The dataset is supplemental to the publication by Groß et al. (2020). For further details on the sample mineralogy and microstructure not provided in the data description file, we refer to this publication. The data was initially collected for a thermobarometry study of the region in the framework of the priority programme SPP 4DMB, funded by the German Research Association (DFG).Sample description:Sample PG61 is an example of a chloritoid-micaschist from the Piffkar Formation. Sample coordinates are UTM Zone 33N: 337044 E, 5216460 N (WGS84, 12.85326 E, 47.081526 N). It contains quartz, phengite, chloritoid, some chlorite, ilmenite (mix of ilmenite, geikielite, Fe-oxide) and relicts of sceletal garnet (as palisades along quartz grain boundaries) and accessory allanite. Rutile occurs as inclusions in quartz and no lawsonite, kyanite or carpholite were found.Sample PG89 is an example of a garnet-micaschist from the Brennkogel Formation. Sample coordinates are UTM Zone 33N: 341888 E, 5207230 N. (WGS 84, 12.920259 E, 46.999701 N) It contains quartz, phengite, garnet, chlorite, albite, tourmaline and rutile (often with ilmenite margins). No lawsonite, paragonite, glaucophane or omphacite was found.Analytical procedure:The compositions of rock forming minerals (white mica, garnet, chloritoid and chlorite) were aquired on a JEOL JXA 8200 SuperProbe at Freie Universität Berlin, Institut für Geologische Wissenschaften. Measurement conditions for spot analyses were 15 kV acceleration voltage, 20 nA beam current and <1 μm beam diameter. We used natural and synthetic reference materials for instrument calibration.

Fault slip inversion data from the Mur-Mürz fault, Eastern Alps

The data set provides the results fault slip inversion analysis, which have been performed with the computer software WinTensor (Delvaux and Sperner, 2003). The raw data underlying these results have been collected during two field campaigns in the Eastern Alps in 2011 and 2013. The data table contains information on the sites where the data collection took place (longitude, latitude in WGS84 coordinate system) as well as results of Win-Tensor calculations including the orientation of the principle finite stress axes (σ1, σ2, σ3), the shape factor (R) and the deformation regime index (R’) (Delveaux et al., 1997). Furthermore, it is shown how many fault-slip data (N) the stress tensor calculation is based on and to which deformation phase as explained in the main text the tensor is related to. The remaining abbreviations include: Outcrop number (ID), dip direction (d.d.), Normal Faulting (NF), Transtensive Faulting (NS), Strike-Slip Faulting (SF), Transpressive Faulting (TS) and Thrust Faulting (TF). The stress regime for each data set is characterized by the stress regime index (R’), which provides a numerically continuous progression from 0-3, where 0 represents radial extension and 3 radial compression (Delvaux et al., 1997). R’ is based on the stress ratio (R), defined as (σ2 – σ3)/ (σ1 – σ3) (e.g. Angelier, 1989) such that R’ equals R for extensional stress regimes, equals 2 – R for strike-slip regimes and equals 2 + R for compressional regimes, respectively (Delvaux et al., 1997).

A database of centrifuge analogue models testing the influence of inherited brittle fabrics on continental rifting

This dataset presents the raw data of an experimental series of analogue models performed to investigate the influence of inherited brittle fabrics on narrow continental rifting. This model series was performed to test the influence of brittle pre-existing fabrics on the rifting deformation by cutting the brittle layer at different orientations with respect to the extension direction. An overview of the experimental series is shown in Table 1. In this dataset we provide four different types of data, that can serve as supporting material and for further analysis: 1) The top-view photos, taken at different steps and showing the deformation process of each model; they can be used to interpret the geometrical characteristics of rift-related faults; 2) Digital Elevation Models (DEMs) used to reconstruct the 3D deformation of the performed analogue models, allowing for quantitative analysis of the fault pattern. 3) Short movies built from top-view photos which help to visualize the evolution of model deformation; 4) line-drawing of fault and fracture patters to be used for fault statistical quantification. Further details on the modelling strategy and setup can be found in Corti (2012), Maestrelli et al. (2020), Molnar et al. (2020), Philippon et al. (2015), Zwaan et al. (2021) and in the publication associated with this dataset. Materials used for these analogue models were described in Montanari et al. (2017) Del Ventisette et al. (2019) and Zwaan et al. (2020).

Stress Magnitude Database Germany

This open access database compiles stress magnitude information from various sources. It currently includes 568 data records in the area of Germany and adjacent regions (latitude: 47 - 55.5 N; longitude: 5.8 - 15.1 E). The data records are ranked after a newly developed quality scheme for stress magnitude data. The data are provided in two formats: Excel-file (stressmagdata_germany_2020.xlsx), comma separated fields (stressmagdata_germany_2020.csv). Additional files include a) an overview over the compiled parameters including the abbreviation keys for stress magnitude indicators and stress regimes (List_of_parameters.pdf); b) the key for the referenced data sources (Key_for_ref_labels.pdf); and c) the applied quality ranking scheme (Quality_ranking_scheme.pdf).

Nanoscale structures and properties of carbonate fault mirrors revealed by scanning electron and scanning transmission electron microscope images, electron energy loss and Raman spectra

This data publication contains scanning electron microscope (SEM) and (scanning) transmission electron microscope ((S)TEM) images as well as electron energy loss spectra (EELS) and Raman spectra of the principal slip surface of carbonate fault mirrors. We analysed a total of eleven samples to investigate the formation mechanisms of fault mirrors in carbonates. The samples were taken as drill cores in Central Greece from two different outcrop locations. The first location, close to Arkitsa, is a large anthropogenic outcrop exposing three large fault planes. The second location is close to Schinos and was also formed by human interaction at the side of a gravel road. The data set contains supplemental material to the publication "Mechanisms of fault mirror formation and fault healing in carbonate rocks" by Ohl et al., (2020). In addition to the electron microscopy images we provide the spectra files of the Raman and EELS measurements for the identification of the carbon species in relation to the principal slip surface. The publication concludes that decarbonation of calcite during fault slip and the subsequent reaction of the decarbonation products produces fault mirror surfaces. Post-seismic hybridization of carbon results in partly-hybridised amorphous carbon and contributes to connecting hanging wall and footwall. In addition, post-seismic carbonation of portlandite produces secondary nano-sized calcite crystals < 50 nm facilitating fault healing.

Ring Shear and Slide-Hold-Slide Test Measurements for Soda-Lime Glassbeads of 300-400µm diameter used at the Helmholtz Laboratory for Tectonic Modelling, Potsdam, Germany

This data set provides two series of experiments from ring-shear tests (RST) on glass beads that are in use at the Helmholtz Laboratory for Tectonic Modelling (HelTec) at the GFZ German Research Centre for Geosciences in Potsdam. The main experimental series contains shear experiments to analyse the slip behaviour of the granular material under analogue experiment conditions. Additionally, a series of slide-hold-slide (SHS) tests was used to determine the rate and state friction properties. A basic characterisation and average friction coefficients of the glass beads are found in Pohlenz et al. (2020). The glass beads show a slip behaviour that is depending on loading rate, normal stress and apparatus stiffness which were varied systematically for this study. The apparatus was modified with springs resulting in 4 different stiffnesses. For each stiffness a set of 4 experiments with different normal stresses (5, 10, 15 and 20 kPa) were performed. During each experiment loading rate was decreased from 0.02 to 0.0008 mm/s resulting in 9 subsets of constant velocity for each experiment. We observe a large variety of slip modes that ranges from pure stick-slip to steady state creep. The main characteristics of these slip modes are the slip velocity and the ratio of slip event duration compared to no slip phases. We find that high loading rates promote stable slip, while low loading rates lead to stick-slip cycles. Lowering the normal stress leads to a larger amount of creep which changes the overall shape of a stick-slip curve and extends the time between slip events. Changing stiffness leads to an overall change in slip behaviour switching from simple stick-slip to more complex patterns of slip modes including oscillations and bimodal slip events with large and small events. The SHS tests were done at maximum stiffness and higher loading rates (>0.05 mm/s) but at the same normal stress intervals as the main series. Using various techniques, we estimate the rate-and-state constitutive parameters. The peak stress after a certain amount of holding increases with a healing rate of b=0.0057±0.0005. From the increase in peak stress compared to the loading rate in slide-hold-slide tests we compute a direct effect a=-0.0076±0.0005 which leads to (a-b)=-0.0130±0.0006. Using a specific subset of the SHS tests, which have an equal ratio of hold time to reloading rate, we estimate (a-b)=-0.0087±0.0029. Both approaches show that the material is velocity weakening with a reduction in friction of 1.30 to 0.87 % per e-fold increase in loading rate. Additionally, the critical slip distance Dc is estimated to be in the range of 200 µm. With these parameters the theoretical critical stiffness kc is estimated and applied to the slip modes found in the main series. We find that the changes in slip mode are in good agreement with the estimated critical stiffness and thus confirm the findings from the SHS tests.

A database of analogue models documenting fault reactivation during multiphase extension.

In this dataset we provide top-view photos and perspective photos (to create topographic data, i.e. Digital Elevation Models, DEMs) documenting analogue model deformation. For more details on modelling setup, experimental series Wang et al. (2021), to which this dataset is supplementary material. For details on analogue materials refer to Del Ventisette et al., 2019, Maestrelli et al. (2020). The analogue modelling experiments were carried out at the TOOLab (Tectonic Modelling Laboratory) of the Institute of Geosciences and Earth Resources of the National Research Council of Italy, Italy, and the Department of Earth Sciences of the University of Florence. The laboratory work that produced these data was supported by the European Plate Observing System (EPOS) and by the Joint Research Unit (JRU) EPOS Italia. Additional analysis, following the original work, was supported by the “Monitoring Earth’s Evolution and Tectonics” (MEET) project

Digital Image Correlation data from experiments of releasing bend evolution within different strength wet kaolin

The data set includes the Digital Image Correlation (DIC) results for four experiments of releasing bends along dextral strike-slip faults that were performed at the University of Massachusetts at Amherst (USA). Gabriel et al. (in prep.) used the DIC data sets to investigate how releasing bend fault systems evolve within different strength wet kaolin. Information on the experimental set up and methods can be found in the main text and supplement to Gabriel et al. (in prep.). The data here include the incremental displacement time series, strain animation and surface elevation data at the end of the two experiments with different clay strength, which are presented within Gabriel et al. (in prep). We also include in this data repository incremental displacement time series and strain animations from two experiments that repeat the conditions of the experiments featured in Gabriel et al. (2025).

A database of R-R-R triple junction analogue and numerical models

This dataset presents the raw data from two experimental series of analogue models and four numerical models performed to investigate Rift-Rift-Rift triple junction dynamics, supporting the modelling results described in the submitted paper. Numerical models were run in order to support the outcomes obtained from the analogue models. Our experimental series tested the case of a totally symmetric RRR junction (with rift branch angles trending at 120° and direction of stretching similarly trending at 120°; SY Series) or a less symmetric triple junction (with rift branches trending at 120° but with one of these experiencing orthogonal extension; OR Series), and testing the role of a single or two phases of extension coupled with effect of differential velocities between the three moving plates. An overview of the performed analogue and numerical models is provided in Table 1. Analogue models have been analysed quantitatively by means of photogrammetric reconstruction of Digital Elevation Model (DEM) used for 3D quantification of the deformation, and top-view photo analysis for qualitative descriptions. The analogue materials used in the setup of these models are described in Montanari et al. (2017), Del Ventisette et al. (2019) and Maestrelli et al. (2020). Numerical models were run with the finite element software ASPECT (e.g., Kronbichler et al., 2012; Heister et al., 2017; Rose et al., 2017).

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