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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.

Decorated dislocations and (HR-)EBSD data from olivine of the Oman-UAE ophiolite

This dataset is supplemental to the paper Wallis et al. (2021) and contains data on dislocations and their stress fields in olivine from the Oman-UAE ophiolite measured by oxidation decoration, electron backscatter diffraction (EBSD) and high-angular resolution electron backscatter diffraction (HR-EBSD). The datasets include images of decorated dislocations, measurements of lattice orientation and misorientations, densities of geometrically necessary dislocations, and heterogeneity in residual stress. Data are provided as 6 TIF files, 8 CTF files, and 37 tab-delimited TXT files. Files are organised by the figure in which the data are presented in the main paper. Data types or sample numbers are also indicated in the file names.

Rheology of PDMS-corundum sand mixtures from the Tectonic Modelling Lab of the University of Bern (CH)

This dataset provides rheometric data of silicone (Polydimethylsiloxane, PDMS SGM36)-corundum sand mixtures used for analogue modelling in Zwaan et al. (2016, 2017), Zwaan and Schreurs (2017) and in the Tectonic Modelling Lab of the Institute of Geological Sciences at the University of Bern (CH). The PDMS is produced by Dow Corning and its characteristics have been described by e.g. Rudolf et al. (2016a,b). The corundum sand (Normalkorund Braun 95.5% F120 by Carlo Bernasconi AG: https://www.carloag.ch/shop/catalog/product/view/id/643), has a grainsize of 0.088-0.125 mm and a specific density of 3.96 g cm^-3. Further rheological characteristics are described by Panien et al. (2006). The density of the tested materials ranges between 1 (pure PDMS) and 1.6 g cm^-3 (increasing corundum sand content in mixture). The material samples have been analysed 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. 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 quasi Newtonian at strain rates below 10^-3*s^-1 and weakly shear rate thinning above. Viscosity and stress exponent increase systematically with density from ~4*10^4 to ~1*10^5 Pa*s and from 1.06 to 1.10, respectively. A first application of the materials tested can be found in Zwaan et al. (2016). Detailed information about the data, methodology and a list of files and formats is given in the "data description" and "list of files" that are included in the zip folder and also available via the DOI landing page.

Ring-shear test data of corundum sand “NKF120” used for analogue modelling in the experimental tectonics laboratory at GFZ Potsdam

This dataset provides friction data from ring-shear tests on corundum sand “NKF120” used in analogue modelling of tectonic processes as a rock analogue for “strong” or “high density” layers in the earth’s upper crust (e.g. Klinkmüller et al., 2016) or as an additive to PDMS silicone oil to increase its density and non-linearity (Zwaan et al., 2018). According to our analysis the material shows a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of corundum sand are µP = 0.75, µD = 0.57, and µR = 0.62, respectively (Table 5). Cohesion of the material ranges between 100-150 Pa. The material shows a minor rate-weakening of ~1% per ten-fold change in shear velocity v and a stick-slip behaviour at low shear velocities. The tested bulk material consists of corundum sand with grain size of 90-120 µm (Table 1). Corundum sand is produced as industrial abrasive materials and sold e.g. by the company Nico Bosse Strahlmittel Berlin. The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994, 2003, 2008) at HelTec, the Laboratory for experimental tectonics at the Helmholtz Center Potsdam – GFZ German Research Centre for Geosciences in Potsdam, Germany.

Ring-shear test data of wallnut shells used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing))

This dataset provides friction data from ring-shear tests walnut shells used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing). According to our analysis the tested materials behave as a Mohr-Coulomb material characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of corundum sand are µP = 0.90, µD = 0.63, and µR = 0.68, respectively (Table 4). Cohesion of the material ranges between 0-40 Pa. The tested bulk material consists of walnut shells with grain size of 180-380 µm (Table 1) and is sold under the name "Walnut Shells" with the product number YR-98547 by the company Yiran Mineral Products (1688.com). The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994, 2003, 2008) at HelTec, the Laboratory for experimental tectonics at the Helmholtz Center Potsdam – GFZ German Research Centre for Geosciences in Potsdam, Germany. The RST is specially designed to measure friction coefficients µ and cohesions C in loose granular material accurately at low confining pressures (<20 kPa) and shear velocities (<1 mm/sec) similar to sandbox experiments. In this tester, a granular bulk material layer is sheared internally at constant normal stress σN and shear velocity v while shear force and lid displacement (corresponding to density and volume change ΔV) are measured continuously. For more details see Klinkmüller et al. (2016).

Ring-shear test data of foamglass used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing)

This dataset provides friction data from ring-shear tests foamglass used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing). According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of corundum sand are µP = 0.55, µD = 0.52, and µR = 0.57, respectively (Table 4). Cohesion of the material ranges between 10-30 Pa. The tested bulk material consists of foamglass with grain size of 180-380 µm (Table 1) and is sold under the name "Floating Bead" with the product number PZ-002 by the company Tuyun Mineral Products (1688.com). The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994, 2003, 2008) at HelTec, the Laboratory for experimental tectonics at the Helmholtz Center Potsdam – GFZ German Research Centre for Geosciences in Potsdam, Germany. The RST is specially designed to measure friction coefficients µ and cohesions C in loose granular material accurately at low confining pressures (<20 kPa) and shear velocities (<1 mm/sec) similar to sandbox experiments. In this tester, a granular bulk material layer is sheared internally at constant normal stress σN and shear velocity v while shear force and lid displacement (corresponding to density and volume change ΔV) are measured continuously. For more details see Klinkmüller et al. (2016).

Ring-shear test data of mica used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing)

This dataset provides friction data from ring-shear tests black mica used for analogue modelling in the experimental tectonics laboratory at China University of Petroleum (Beijing). According to our analysis the materials show a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of corundum sand are µP = 0.59, µD = 0.56, and µR = 0.57, respectively (Table 4). Cohesion of the material ranges between 100-130 Pa. The tested bulk material consists of black mica (Biotite) with grain size of 380-830 µm and is sold under the name "Black Mica" with the product number YS-004 by the company Yunshi Building Materials Co., Ltd (1688.com). The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994, 2003, 2008) at HelTec, the Laboratory for experimental tectonics at the Helmholtz Center Potsdam – GFZ German Research Centre for Geosciences in Potsdam, Germany. The RST is specially designed to measure friction coefficients µ and cohesions C in loose granular material accurately at low confining pressures (<20 kPa) and shear velocities (<1 mm/sec) similar to sandbox experiments. In this tester, a granular bulk material layer is sheared internally at constant normal stress σN and shear velocity v while shear force and lid displacement (corresponding to density and volume change ΔV) are measured continuously. For more details see Klinkmüller et al. (2016).

Compaction creep data uniaxial compaction of quartz sand in various chemical environments

We studied the effect of pore fluid chemistry on compaction creep in quartz sand aggregates, as an analogue for clean, highly porous, quartz-rich reservoir sands and sandstone. Creep is specifically addressed, because it is not yet well understood and can potentially cause reservoir compaction even after production has ceased. Going beyond previous work, we focused on fluids typically considered for pressure maintenance or for permanent storage, e.g. water, wastewater, CO2 and N2, as well as agents, such as AlCl3, a quartz dissolution inhibitor, and scaling inhibitors used in water treatment facilities and geothermal energy production. Uniaxial (oedometer) compaction experiments were performed on cylindrical sand samples at constant effective stress (35 MPa) and constant temperature (80 °C), simulating typical reservoir depths of 2-4 km. Insight into the deformation mechanisms operating at the grain scale was obtained via acoustic emission (AE) counting, and by means of microstructural study and grain size analysis applied before and after individual compaction tests.

Ring-shear test data of garnet sand used for analogue modelling in the experimental tectonics laboratory at GFZ German Research Centre for Geosciences, Potsdam

This dataset provides friction data from ring-shear tests on garnet sand used in analogue modelling of tectonic processes as a rock analogue for “strong” or “high density” layers in the earth’s upper crust (e.g. Klinkmüller et al., 2016). According to our analysis the material shows a Mohr-Coulomb behaviour characterized by a linear failure envelope. Peak, dynamic and reactivation friction coefficients of garnet sand are µP = 0.83, µD = 0.61, and µR = 0.73, respectively (Table 5). Cohesion of the material ranges between 20-120 Pa. The material shows a no significant rate-dependency. The data presented here are derived by ring shear testing using a SCHULZE RST-01.pc (Schulze, 1994, 2003, 2008) at HelTec, the Laboratory for experimental tectonics at the Helmholtz Center Potsdam – GFZ German Research Centre for Geosciences in Potsdam, Germany. The RST is specially designed to measure friction coefficients µ and cohesions C in loose granular material accurately at low confining pressures (<20 kPa) and shear velocities (<1 mm/sec) similar to sandbox experiments. In this tester, a granular bulk material layer is sheared internally at constant normal stress σN and shear velocity v while shear force and lid displacement (corresponding to density and volume change ΔV) are measured continuously. For more details see Klinkmüller et al. (2016).

Trace element concentration of minerals in the Morro São João malignites (Serra do Mar, Brazil)

The Morro São João intrusion is located in the easternmost part of the Serra do Mar province, along the Cabo Frio lineament (Fig. 1) and has an area of approximately 10 km². It is a Late Cretaceous intrusion formed by clinopyroxenites, melagabbros, shonkinites, malignites, nepheline syenites, and phonolite dikes, without olivine, and is thought to have formed by closed system crystallization of a fairly evolved tephritic melt of potassic/ultrapotassic affinity (cf. Brotzu et al., 2007). We have analyzed two malignites, and specifically, their liquidus phases (clinopyroxene, titanite, garnet, amphibole). Analyzing the trace elements in these minerals helps us to better understand the different fractionation of the elements in these coexisting phases, and the implications for the evolution processes that occurred in the Morro São João magma reservoir. These analyses also provided important information about the concentration of rare earth elements (REEs) and high field strength elements (HFSEs), and their change with the magmatic evolution of the suite. This publication results from work conducted under the transnational access/national open access action at Mass spectrometry la-icp laboratory (IGG-CNR, Italy) supported by WP3 ILGE - MEET project, PNRR - EU Next Generation Europe program, MUR grant number D53C22001400005.

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