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Rheology of viscous materials from the CNR-IGG Tectonic Modelling Laboratory at the University of Florence (Italy)

This dataset provides rheometric data of three viscous materials used for centrifuge experiments at the Tectonic Modelling Laboratory of CNR-IGG at the Earth Sciences Department of the University of Florence (Italy). The first material, PP45, is a mixture of a silicone (Polydimethylsiloxane or PDMS SGM36) and plasticine (Giotto Pongo). The PDMS is produced by Dow Corning and its characteristics are described by e.g. Rudolf et al. 2016a,b). Giotto Pongo is produced by FILA (Italy). Both components are mixed following a weight ratio of 100:45, and the final mixture has a density of 1520 kg m3. The second material, SCA705 is a mixture of Dow Corning 3179 putty, mixed with fine corundum sand and oleic acid with a weight ratio of 100:70:05 and a resulting density of 1660 kg m3. The final material, SCA7020 consists of the same components as SCA705, but with a slightly higher oleic acid content reflected in the weight ratio of 100:70:20. The mixture’s density is 1620 kg m3. The material samples have been analyzed in the Helmholtz Laboratory for Tectonic Modelling (HelTec) at GFZ German Research Centre for Geosciences in Potsdam using an Anton Paar Physica MCR 301 rheometer in a plate-plate configuration at room temperature (20˚C). Rotational (controlled shear rate) tests with shear rates varying from 10-4 to 1 s-1 were performed. Additional temperature tests were run with shear rates between 10-2 to 10-1 s-1 for a temperature range between 15 and 30˚C. According to our rheometric analysis, the materials all exhibit shear thinning behavior, with high power law exponents (n-number) for strain rates below 10-2s-1, while power law exponents are lower above that threshold.For PP45, the respective n-numbers are 4.8 and 2.6, for SCA705 6.7 and 1.5, and for SCA7020 9.1 and 2.0. The temperature tests show decreasing viscosities with increasing temperatures with rates of -3.8, -1.4 and -1.9% per ˚K for PP45, SCA705 and SCA7020, respectively. An application of the materials tested can be found in Zwaan et al. (2020).

Rheology of PDMS silicones used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (CUP)

This dataset provides rheometric data of three PDMS silicones used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (CUP). The material samples have been analyzed at the Laboratory for Experimental Tectonics at GFZ Helmholtz Centre for Geosciences, Potsdam (HelTec) using an Anton Paar Physica MCR 301 rheometer in a plate-plate configuration at room temperature (21˚C). Rotational (controlled shear rate) tests with shear rates varying from 10^4 to 1 s^-1 were performed. According to our rheometric analysis, the material is quasi-Newtonian (n~1) at strain rates below 10-2 s-1 and weakly shear rate thinning above. The viscosities of the three materials range between 8*10^4 to 3*10^5 Pa s.

Rheology of PDMS-plasticine mixtures from the Tectonic Modelling Laboratory at CNR-IGG and the University of Florence (Italy)

This dataset provides rheometric data of three PDMS-plasticine mixtures used for centrifuge experiments at the Tectonic Modelling Laboratory of CNR-IGG at the Department of Earth Sciences of the University of Florence (Italy). The test became necessary as older plasticines used in PDMS-plasticine mixtures characterized rheologically in Zwaan et al. (2020) became unavailable. The material samples have been analyzed at the Laboratory for Experimental Tectonics at GFZ Helmholtz Centre for Geosciences, Potsdam (HelTec) using an Anton Paar Physica MCR 301 rheometer in a plate-plate configuration at room temperature (21˚C). Rotational (controlled shear rate) tests with shear rates varying from 10^-4 to 1 s^-1 were performed. According to our rheometric analysis, the new materials cover a range of viscosities from 8E^+04 to 4E^+07 Pas. They exhibit shear thinning behavior with high power law exponents (n-number). For PP45-1, PP45-2 and PP100, the respective n-numbers are 10, 8 and 3 at shear rates above 10^-3s^-1 and around 2 below.

Rheology of PDMS Korasilon fluids M used at the Laboratory for Experimental Tectonics at GFZ Helmholtz Centre for Geosciences, Potsdam, Germany

This dataset provides rheometric data of PDMS Korasilon® Fluids M used for analogue modelling at the Laboratory for Experimental Tectonics at GFZ Helmholtz Centre for Geosciences, Potsdam, Germany. The material samples have been analyzed at the Laboratory for Experimental Tectonics at GFZ Helmholtz Centre for Geosciences, Potsdam (HelTec) using an Anton Paar Physica MCR 301 rheometer in a plate-plate configuration at room temperature (21˚C). Rotational (controlled shear rate) tests with shear rates varying from 10^-4 to 10^-1 s^-1 were performed. According to our rheometric analysis, the material is Newtonian (n = 1) at strain rates below 1 s-1. The viscosities range from 10 to 2000 Pa s.

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 analogue modelling experiments addressing extension of weakened crust

This data set includes the results of digital image correlation analysis applied to analogue modelling experiments (Table 1) on the effect of weakness during distributed crustal extension performed at the Helmholtz Laboratory for Tectonic Modelling (HelTec) of the GFZ German Research Centre for Geosciences in Potsdam. Ten generic analogue models made of a layer of Quartz sand (G12, Rosenau et al., 2018) including a weak silicone oil “seed” (PDMS G30M, Rudolf et al., 2016) to localize deformation have been extended on top of a basal foam block. A benchmark experiment (basal foam only) and a reference model (layer of sand without seed) are also reported. Detailed descriptions of the experiments can be found in Osagiede et al. (2021) to which this data set is supplement. The models have been monitored by means of digital image correlation (DIC) analysis (Adam et al., 2005). DIC analysis yields quantitative information about model surface deformation in 2D and 3D. The data presented here are visualized as finite strain and displacement maps as well as cumulative strain and displacement profiles.

Rheometric Analysis of Viscous Material Mixtures Used in the Tectonic Laboratory (TecLab) at Utrecht University, Netherlands

This dataset contains measurements of viscous and viscoelastic materials that are used for analogue modelling. Proper density and viscosity scaling of ductile layers in the crust and lithosphere, requires materials like Polydimethylsiloxane (PDMS), to be mixed with fillers and low viscoity silicone oils. Changing the filler content and filler material, the density, viscosity and power-law coefficient can be tuned according to the requirements. All materials contain a large amount of PDMS and all but one a small amount of an additional silicone oil. Adding plasticine or barium sulfate lead to shear thinning rheologies with power-law exponents of p<0.95. Adding corundum powder only has a minor effect on the power-law exponent. Some mixtures also have an apparent yield point but all are in the liquid state in the tested range. In general, the rheologies of the materials are very complex and in some cases strongly temperature dependent. However, in the narrow range of relevant strain rates, the behaviour is well defined by a power-law relation and thus found suitable for simulating ductile layers in crust and lithosphere.

Supplement to “Synchronization of great subduction megathrust earthquakes: Insights from scale model analysis”

This data set provides data from subduction zone earthquake experiments and analysis described in Rosenau et al. (2019). In the experiments analogue seismotectonic scale models of subduction zones characterized by two seismogenic asperities are used to study the interaction of asperities over multiple seismic cycles by means of static (Coulomb failure) stress transfer. Various asperity geometries (lateral/along-strike of the subduction zone distance and vertical/across-strike of the subduction zone offset) are tested on their effect on recurrence pattern of simulated great (M8+) earthquakes.The results demonstrate the role of stress coupling in the synchronization of asperities leading to multi-asperity M9+ events in nature. The data set contains time series of experimental surface velocities from which analogue earthquakes are detected and classified into synchronized events and solo events. The latter are subcategorized into main events and aftershocks and into normal and thrust events. An analogue earthquake catalogue lists all categorized events of the 12 experiments used for statistical analysis. Moreover, results from elastic dislocation modelling aimed ate quantifying the stress coupling between the asperities for the various geometries are summarized. Basic statistics of classified events (e.g. percentage of categorized events, coefficient of variation in size and recurrence time etc.) are documented. Matlab scripts are provided to visualize the data as in the paper.

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).

4D X-Ray CT data and surface view videos of analogue models exploring rift interaction in orthogonal and rotational extension

This data set includes videos depicting the surface evolution of 29 analogue models on crustal extension, as well as 4D CT imagery (figures and videos) of two of these experiments. The experiments examined the influence of the method for driving extension (orthogonal or rotational) on the interaction between rift segments using a brittle-viscous set-up. All experiments were performed at the Tectonic Modelling Laboratory of the University of Bern, Bern, Switzerland (UB). Brittle and viscous layers are both 4 cm thick, extension velocities are 8 mm/h so that a model duration of 5 h yields a total extension of 40 mm (e = ca. 13%, given an initial model width of ca. 30 mm). Next to the mode of extension (orthogonal or rotational), we also test the effect of the degree of onderlap (angle φ). Detailed descriptions of the experiments and monitoring techniques can be found in Zwaan et al. (2020).

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