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A database of analogue models and geophysical data investigating caldera resurgence; DynamiCal project

In this dataset we provide data for 6 experimental models of caldera collapse and subsequent resurgence monitored through geophysical sensors (a force or “impact sensor”, Piezotronics PCB 104 200B02 and a Triaxial piezoelectric accelerometer, Model 356B18). The analogue modelling experiments were carried out at the TOOLab (Tectonic Modelling Laboratory), which is a joint laboratory between the Istituto di Geoscienze e Georisorse of the Consiglio Nazionale delle Ricerche, Italy and the Department of Earth Sciences of the University of Florence. The laboratory work that produced these data was partly supported by the European Plate Observing System (EPOS), by the Joint Research Unit (JRU) EPOS Italia and by the “Monitoring Earth's Evolution and Tectonics” (MEET) project (NextGenerationEU). Specifically, this work was performed in the frame of the DynamiCal project, funded by the 2° TNA-NOA call of the ILGE-MEET project.

Results of analogue tectonic models of rifting and tectonic lineament reactivation along the Main Ethiopian Rift

This data set includes results from a total of 13 analogue tectonic models aimed at simulating the activation of tectonic lineaments associated with the Main Ethiopian Rift in eastern Africa. We use a model set-up based on previous work by Zwaan et al. (2021, 2022). This set-up involves a velocity discontinuity (VD, i.e., the edge of a mobile base plate) to induce extension in the overlying brittle- and viscous model materials representing the upper and lower crust, respectively. Additional structural weaknesses (seeds) at the base of the brittle layer serve to represent activated tectonic weaknesses in nature. Model parameters (different VD and seed orientation, and different seed diameters) are summarized in Table 1. The model results presented in this data publication are obtained through Digital Image Correlation (DIC) and Structure-from-Motion (SfM) analyses. A more detailed description of model set-up, model results, and their interpretation can be found in Zwaan et al. (2025)

Overviews and videos of top view imagery, topography data and DIC analysis results from analogue models of basin inversion

This data set includes videos depicting the surface evolution (time-lapse photography, topography data and Digital Image Correlation [DIC] analysis) of 11 analogue models, divided in three model series (A, B and C), simulating rifting and subsequent inversion tectonics. In these models we test how orthogonal or oblique extension, followed by either orthogonal or oblique compression, as well as syn-rift sedimentation, influenced the reactivation of rift structures and the development of new inversion structures. We compare these models with an intracontinental inverted basin in NE Brazil (Araripe Basin). All experiments were performed at the Tectonic Modelling Laboratory of the University of Bern (UB). We used an experimental set-up involving two long mobile sidewalls, two rubber sidewalls (fixed between the mobile walls, closing the short model ends), and a mobile and a fixed base plate. We positioned a 5 cm high block consisting of an intercalation of foam (1 cm thick) and Plexiglas (0.5 cm thick) bars on the top of the base plates. Then we added layers of viscous and brittle analogue materials representing the ductile and brittle lower and upper crust in our experiments, which were 3 cm and 6 cm thick, respectively. A seed made of the same viscous material was positioned at the base of the brittle layer, in order to localize the formation of an initial graben in our models. The standard model deformation rate was 20 mm/h, over a duration of 2 hours for a total of 40 mm of divergence, followed by 2 hours of convergence at the same rate (except for Models B3 and C3, since the oblique rifting did not create space for 40 mm of orthogonal inversion). For syn-rift sedimentation, we applied an intercalation of feldspar and quartz sand in the graben. Model parameters and detailed description of model set-up are summarized in Table 1, and results and their interpretation can be found in Richetti et al. (2023).

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

Surface deformation and topography data from analogue modelling experiments addressing triaxial tectonics in regions of distributed extension

This data set includes the results of high-resolution digital elevation models (DEM) and digital image correlation (DIC) analysis applied to analogue modelling experiments. Twenty generic analogue models are extended on top of a rubber sheet. Two benchmark experiments are also reported. Detailed descriptions of the experiments can be found in Liu et al. (submitted) to which this data set is supplement. The data presented here are visualized as topography and the horizontal cumulative surface strain (principal strain and slip rake).

Ring-shear test data of wheat flour used for analogue experiments in the laboratory of the Institute of Geophysics of the Czech Academy of Science, Prague

This dataset provides friction data from ring-shear tests (RST) for wheat flour used as a fine-grained, cohesive analogue material for simulating brittle upper crustal rocks in the analogue labor-atory of the Institute of Geophysics of the Czech Academy of Science (IGCAS). It is characterized by means of internal friction coefficients µ and cohesion C. According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak friction coefficients µP of the tested material is ~0.72, dynamic friction coeffi-cients µD is ~0.67 and reactivation friction coefficients µR is ~0.70. Cohesions of the material range between 27 and 50 Pa. The material shows a minor rate-weakening of ~1.5% per ten-fold change in shear velocity v and a stick-slip behaviour at low shear velocities.

Effect of sieving height on density and friction of brittle analogue material: Ring-shear test data of quarz sand used for analogue experiments in the Tectonic Modelling Lab of the University of Bern

This dataset provides friction data from ring-shear tests (RST) for a quartz sand (“A”). This material is used in various types of analogue experiments in Tectonic Modelling Lab of the University of Bern as an analogue for brittle layers in the crust or lithosphere. The material has been characterized by means of internal friction coefficients μ and cohesions C. Three sub-datasets represent a systematic increase of the sieving height from 10 cm to 20 cm to 30 cm into a shear cell of type No. 1, following the same protocol. This dataset shows that packing density of quartz sand is dependent on the chosen sieving height. However, the effect of the sieving height on internal friction coefficients μ as well as cohesion C is minor and thus negligible in sandbox experiments. According to our analysis the material shows for a sieving height of 10 cm a Mohr-Coulomb behaviour characterized by a linear failure envelope and peak, dynamic and reactivation friction coefficients of μP = 0.70, μD = 0.60 and μR = 0.65, respectively. Cohesions C are in the order of 40 – 80 Pa.

Ring shear test data of glass beads 300-400 µm used for analogue experiments in the Helmholtz Laboratory for Tectonic Modelling (HelTec) at the GFZ German Research Centre for Geosciences in Potsdam

This dataset provides friction data from ring-shear tests (RST) on glass beads used in the Helmholtz Laboratory for Tectonic Modelling (HelTec) at the GFZ German Research Centre for Geosciences in Potsdam as an analogue for “weak” brittle layers in the crust or lithosphere (Ritter et al., 2016; Santimano et al., 2015; Contardo et al., 2011; Reiter et al., 2011; Hoth et al., 2007, 2006; Kenkmann et al., 2007; Deng et al., 2018) or in stick-slip experiments (Rudolf et al., 2019). The glass beads with a diameter of 300-400 µm have been characterized by means of internal friction coefficients µ and cohesions C as a remote service by the Helmholtz Laboratory for Tectonic Modelling (HelTec) at the GFZ German Research Centre for Geosciences in Potsdam. According to our analysis the material shows a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of the glass beads are µP = 0.58, µD = 0.43 and µR = 0.49, respectively. Cohesion ranges between 8 and 81 Pa. A rate-weakening of ~7 % per ten-fold change in shear velocity v is evident.

Digital image correlation data from laboratory subduction megathrust models

This data set includes digital image correlation data from analog earthquakes experiments. The data consists of grids of surface strain and time series of surface displacement (horizontal and vertical) and strain. The data have been derived using a stereo camera setup and processed with LaVision Davis 10 software. Detailed descriptions of the experiments and results regarding the surface pattern of the strain can be found in Kosari et al. (2022), to which this data set is supplementary. We use an analog seismotectonic scale model approach (Rosenau et al., 2019 and 2017) to generate a catalog of analog megathrust earthquakes (Table 1). The presented experimental setup is modified from the 3D setup used in Rosenau et al. (2019) and Kosari et al. ( 2020). The subduction forearc model wedge is set up in a glass-sided box (1000 mm across strike, 800mm along strike, and 300 mm deep) with a dipping, elastic basal conveyor belt and a rigid backwall. An elastoplastic sand-rubber mixture (50 vol.% quartz sandG12: 50 vol.% EPDM rubber) is sieved into the setup representing a 240 km long forearc segment from the trench to the volcanic arc. The shallow part of the wedge includes a basal layer of sticky rice grains characterized by unstable stick-slip sliding representing the seismogenic zone. Stick-slip sliding in rice is governed by a rate-and-state dependent friction law similar to natural rocks. According to Coulomb wedge theory (Dahlen et al., 1984), two types of wedge configurations have been designed: a “compressional” configuration represents an interseismically compressional and coseismically stable wedge (compressional configuration), and a “critical” configuration, which is interseismically stable (close to critically compressional) and may reach a critical extensional state coseismically (critical configuration). In the compressional configuration, a flat-top (surface slope α=0) wedge overlies a single large rectangular in map view stick-slip patch (Width*Length=200*800 mm) over a 15-degree dipping basal thrust. In the critical configuration, the surface angle of the elastoplastic wedge varies from the coastal segment onshore (α=10) to the inner-wedge offshore (α=15) segments over a 5-degree dipping basal thrust. Slow continuous compression of the wedge by moving the basal conveyor belt at a speed velocity of 0.05 mm/s simulates plate convergence and results in the quasi-periodic nucleation of quasi-periodic stick-slip events (analog earthquakes) within the rice layer. The wedge responds elastically to these basal slip events, similar to crustal rebound during natural subduction megathrust earthquakes.

High-speed digital image correlation data from laboratory subduction megathrust models

This data set includes data derived from high-speed surface displacement observations from analog earthquake experiments. The data consists of surface displacement of the experiment upper plate and slab, slip distribution, and grids of Coulomb Failure Stress (CFS). The surface displacement observations have been captured using a highspeed CMOS (Complementary Metal Oxide Semiconductor) camera (Phantom VEO 640L camera, 12 bit) and processed with LaVision Davis 10 software. Description of the experiments and results regarding the surface displacement observation, Slip distribution, and CFS can be found in Kosari et al. (2022), to which this data set is supplementary. We use an analog seismotectonic scale model approach (Rosenau et al., 2019 and 2017) to generate a catalog of analog megathrust earthquakes. The presented experimental setup is modified from the 3D setup used in Rosenau et al. (2019) and Kosari et al. ( 2020 and 2022). The subduction forearc model wedge is set up in a glass-sided box (1000 mm across strike, 800mm along strike, and 300 mm deep) with a dipping, elastic basal conveyor belt, and a rigid backwall. An elastoplastic sand-rubber mixture (50 vol.% quartz sandG12: 50 vol.% EPDM rubber) is sieved into the setup representing a 240 km long forearc segment from the trench to the volcanic arc. The shallow part of the wedge includes a basal layer of sticky rice grains characterized by unstable stick-slip sliding representing the seismogenic zone. The Stick-slip sliding in rice is governed by a rate-and-state dependent friction law similar to natural rocks. A flat-top (surface slope α=0) wedge overlies rectangular stick-slip patch/es over a 15-degree dipping basal thrust. Two different seismic configurations of the shallow part of the wedge base (the megathrust) represent the depth extent of the seismogenic zone in nature. In the first configuration (homogeneous configuration), a single large rectangular stick-slip patch (Width*Length=200*800 mm) is implemented as the main slip patch (MSP). In the second case (heterogeneous configuration), two square-shaped MSPs (200*200mm) have been emplaced, acting as two medium-size seismogenic asperities surrounded by a salt matrix hosting frequent small events. Slow continuous compression of the wedge by moving the basal conveyor belt at a speed velocity of 0.05 mm/s simulates plate convergence and results in the quasi-periodic nucleation of quasi-periodic stick-slip events (analog earthquakes) within the sticky-rice layer. The wedge responds elastically to these basal slip events, similar to crustal rebound during natural subduction megathrust earthquakes.

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