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Hypocentral temperatures, geothermal gradients, crustal seismogenic depths and 3D thermal model of the Southern Caribbean and NW South America

This data repository for the Southern Caribbean and NW South America contains a 3D thermal model computed down to 75 km depth, the modelled hypocentral temperatures and geothermal gradients at the locations of crustal earthquakes, and the crustal seismogenic depths calculated from earthquake statistics, as well as the associated modelled temperatures. We used the uppermost 75 km of the gravity-constrained structural and density model of Gómez-García et al. (2020, 2021) to derive the 3D thermal configuration of the study area (5°-15° N, 63°-82° W). A steady-state approach was followed, in which upper and lower boundary conditions were set to run the thermal calculations using the software GOLEM (Cacace & Jacquey, 2017; Jacquey & Cacace, 2017). A catalogue of earthquakes occurred within the study area and surroundings was compiled from public sources. In the database archived here, we provide data of the best located crustal earthquakes within the boundaries of this area, from January 1980 to June 2021. Earthquakes below the magnitude of completeness, or with poorly determined depths, were disregarded. Earthquakes were deemed crustal if their hypocentres were located between the topo-bathymetry from the GEBCO relief (Weatherall et al., 2015) and the Moho depth from the GEMMA model (Reguzzoni & Sampietro, 2015). We computed the crustal seismogenic depth as the 90th and 95th percentiles (D90 and D95), respectively, of the crustal hypocentral depths. These percentiles were mapped on a latitude-longitude grid, using for each grid node at least the 20 closest earthquakes as sample. The hypocentral temperatures, the geothermal gradient at the earthquake locations, and the temperatures at the D90 and D95 surfaces were calculated from the lithospheric-scale thermal model. For more details about the modelling approach and interpretation of the results, we kindly ask the reader to refer to the main publication: Gomez-Garcia et al. (2023).

Catalogues of bulge and fountain formation at Strokkur geyser in 2017, 2020 and 2022: Heights, rising speeds and seismic signal

Strokkur is a pool geyser in southwest Iceland that erupts every 3.7 minutes. Eruptions start with a blue water bulge that soon turns white (bulge phase) before the water bubble bursts into a jetting water fountain (jet phase). We measured the bulge rising velocity and height and fountain rising velocity and height using video cameras and drones from GFZ and the accompanying ground motion using seismometers from the University of Potsdam. We publish the derived products from video data and seismic data here.

Hypocentral temperatures, crustal seismogenic thickness and 3D thermal model of the South Caribbean and NW South America

This data repository contains the 3D steady-state thermal field computed for the South Caribbean and NW South America down to 75 km depth, the modelled hypocentral temperatures, the depths to the upper and lower stability transitions, as well as the seismogenic thickness calculated from selected earthquakes of the ISC Bulletin (International Seismological Centre, 2022). All methodological details can be found in the main publication (see section 2). We used the uppermost 75 km of the gravity-constrained structural and density model of Gómez-García et al. (2020, 2021) to derive the 3D thermal configuration of the study area. A steady-state approach was followed, in which upper and lower boundary conditions were set to run the thermal experiments using the software GOLEM (Cacace & Jacquey, 2017; Jacquey & Cacace, 2017). We selected earthquakes from the ISC Bulletin from January 1980 to January 2021 (International Seismological Centre, 2022), considering the magnitude of completeness for different periods, removing earthquakes without depth, set as 0 km or fixed, as well as those with reported hypocentral depth errors >30 km. Of this set, we selected the crustal earthquakes, located between the topo-bathymetry from the GEBCO relief (Weatherall et al., 2015) and the Moho depth from the GEMMA model (Reguzzoni & Sampietro, 2015), interpolated to a resolution of 5 km. From this earthquake subset we computed the upper and lower stability transitions for seismogenesis, as the 10th and 90th percentiles (D10 and D90), respectively, of the hypocentral depths. These percentiles were mapped on a latitude-longitude grid, using for each grid node its 20 closest earthquakes as sample. The hypocentral temperatures and the temperatures at the D10 and D90 crustal depths were calculated from the lithospheric-scale thermal model. Lastly, the crustal seismogenic thickness was computed as the difference between D90 and D10 for each grid node. For more details about the modelling approach and interpretation of the results, we kindly ask the reader to refer to the main publication: Gomez-Garcia et al., (2022).

A database of analogue models testing the interaction between magmatic intrusion-related doming and caldera collapse

This dataset presents the raw data from one experimental series (named CCEX, i.e., Caldera Collapse under regional Extension) of analogue models performed to investigate the process of caldera collapse followed by regional extension. Our experimental series tested the case of perfectly circular collapsed calderas afterward stretched under regional extensional conditions, that resulted in elongated calderas. The models are primarily intended to quantify the role of regional extension on the elongation of collapsed calderas observed in extensional settings, such as the East African Rift System. An overview of the performed analogue 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), Bonini et al., 2021 and Maestrelli et al. (2021a,b).

Thermal property data of drill cores of ICDP project DIVE (5071) and surface samples in the Ivrea-Verbano Zone

This data set was collected in the frame of the ICDP drilling project DIVE (Drilling the Ivrea-Verbano ZonE) to determine the thermal properties of lower crustal lithologies and their variabilities. Two boreholes were drilled, the first 5071_1_B (in Ornavasso, final depth: 578.5 m) intersects the amphibolite-facies metasedimentary succession of the Ivrea-Verbano Zone, and the second borehole 5071_1_A (in Megolo, final depth: 909.5 m) is located within the mafic complex. Thermal properties were measured on fresh drill cores from the two DIVE boreholes and surface samples collected from nearby outcrops. The data set comprises thermal conductivity (TC), thermal diffusivity (TD), and specific heat capacity (Cp) measurements as well as measurements on concentrations of heat producing elements (HPE) Uranium (U), Thorium (Th), and Potassium (K) and the calculated radiogenic heat production (A).

Py4HIP: Python tool for Heat-In-Place calculations

Py4HIP is an open-source software tool for Heat-In-Place calculations implemented as a self-explanatory Jupyter notebook written in Python (Py4HIP.ipynb) Calculating the Heat In Place (HIP) is a standard method for assessing the geothermal potential for a defined geological unit (e.g., Nathenson, 1975; Muffler and Cataldi, 1978; Garg and Combs, 2015). The respective implementation in Py4HIP is based on a volumetric quantification of contained energy after Muffler and Cataldi (1978), where the geological unit at hand is considered spatially variable in terms of its temperature, thickness, porosity, density and volumetric heat capacity of its solid and fluid (brine) components. The energy values provided by Py4HIP as ASCII lists and map representations correspond to the stored energy in J/m^2.