The immense advances in computer power achieved in the last decades have had a significant impact in Earth science, providing valuable research outputs that allow the simulation of complex natural processes and systems, and generating improved forecasts. The development and implementation of innovative geoscientific software is currently evolving towards a sustainable and efficient development by integrating models of different aspects of the Earth system. This will set the foundation for a future digital twin of the Earth. The codification and update of this software require great effort from research groups and therefore, it needs to be preserved for its reuse by future generations of geoscientists. Here, we report on Geo-Soft-CoRe, a Geoscientific Software & Code Repository, hosted at the archive DIGITAL.CSIC. This is an open source, multidisciplinary and multiscale collection of software and code developed to analyze different aspects of the Earth system, encompassing tools to: 1) analyze climate variability; 2) assess hazards, and 3) characterize the structure and dynamics of the solid Earth. Due to the broad range of applications of these software packages, this collection is useful not only for basic research in Earth science, but also for applied research and educational purposes, reducing the gap between the geosciences and the society. By providing each software and code with a permanent identifier (DOI), we ensure its self-sustainability and accomplish the FAIR (Findable, Accessible, Interoperable and Reusable) principles. Therefore, we aim for a more transparent science, transferring knowledge in an easier way to the geoscience community, and encouraging an integrated use of computational infrastructure.Systematic Review Registration: https://digital.csic.es/handle/10261/193580.

Summary This work presents a new methodology designed to estimate the slowness vector in large-aperture sparse Ocean Bottom Seismometer (OBS) arrays. The Continuous Wavelet Transform (CWT) is used to convert the original incoherent traces that span a large array, into coherent impulse functions adapted to the array aperture. Subsequently, these impulse functions are beamformed in the frequency domain to estimate the slowness vector. We compare the performance of this new method with that of an alternative solution, based on the fast Short-Term Average/Long-Term Average algorithm and with a method based on the trace envelope, with the ability to derive a very fast detection and slowness vector estimation of seismic signal arrivals. The new array methodology has been applied to data from an OBS deployment with an aperture of 80 km and an interstation-distance of about 40 km, in the vicinity of Cape Saint Vincent (SW Iberia). A set of 17 regional earthquakes with magnitudes 2 < mbLg < 5, has been selected to test the capabilities of detecting and locating regional seismic events with the Cape Saint Vincent OBS Array. We have found that there is a good agreement between the epicentral locations obtained previously by direct search methods and those calculated using the slowness vector estimations resulting from application of the CWT technique. We show that the proposed CWT method can detect seismic signals and estimate the slowness vector from regional earthquakes with high accuracy and robustness under low signal-to-noise ratio conditions. Differences in epicentral distances applying direct search methods and the CWT technique are between 1 km and 21 km with an average value of 12 km. The back-azimuth differences range from 1° to 7° with an average of 1.5° for the P-wave and ranging from 1° to 10° with an average of 3° for the S-wave.

Seismic-noise tomography is routinely applied for imaging geological structures at different spatial scales. The frequently used time-domain approach presents two limitations. First, extracting surface-wave group velocities from time-domain cross-correlations requires interstation distances of at least three wavelengths, which may be problematic when working at local or regional scales. Second, the presence of higher modes of surface waves in the cross-correlation functions is often disregarded, which may cause loss of valuable information about the shear-wave velocity structure. In this work, we present a complete inversion scheme that avoids these limitations and use it to obtain a 3D shear-wave velocity model of the Basque-Cantabrian Zone (N Spain), a structurally complex area affected by multiple tectonic events. The resulting model agrees with the existing geological and geophysical knowledge and significantly extends the area for which high-resolution information is available.

Abstract. We use 1.5 years of continuous recordings from an amphibious seismic network deployment in the region of northeastern South America and the southeastern Caribbean to study the crustal and uppermost mantle structure through a joint inversion of surface-wave dispersion curves determined from ambient seismic noise and receiver functions. The availability of both ocean bottom seismometers (OBSs) and land stations makes this experiment ideal to determine the best processing methods to extract reliable empirical Green's functions (EGFs) and construct a 3D shear velocity model. Results show EGFs with high signal-to-noise ratio for land–land, land–OBS and OBS–OBS paths from a variety of stacking methods. Using the EGF estimates, we measure phase and group velocity dispersion curves for Rayleigh and Love waves. We complement these observations with receiver functions, which allow us to perform an H-k analysis to obtain Moho depth estimates across the study area. The measured dispersion curves and receiver functions are used in a Bayesian joint inversion to retrieve a series of 1D shear-wave velocity models, which are then interpolated to build a 3D model of the region. Our results display clear contrasts in the oceanic region across the border of the San Sebastian–El Pilar strike-slip fault system as well as a high-velocity region that corresponds well with the continental craton of southeastern Venezuela. We resolve known geological features in our new model, including the Espino Graben and the Guiana Shield provinces, and provide new information about their crustal structures. Furthermore, we image the difference in the crust beneath the Maturín and Guárico sub-basins.

Abstract. We use 1.5 years of continuous recordings from an amphibious seismic network deployment in the region of northeast South America and southeast Caribbean to study the crustal and uppermost mantle structure through a joint inversion of surface wave dispersion curves determined from ambient seismic noise and receiver functions. The availability of both ocean bottom seismometers (OBSs) and land stations makes this experiment ideal to determine the best processing methods to extract reliable empirical Green’s functions (EGFs) and construct a 3D shear velocity model. Results show EGFs with high signal-to-noise ratio for land-land, land-OBS and OBS-OBS paths from a variety of stacking methods. Using the EGF estimates, we measure phase and group velocity dispersion curves for Rayleigh and Love waves. We complement these observations with receiver functions, which allow us to perform an H-k analysis to obtain Moho depth estimates across the study area. The measured dispersion curves and receiver functions are used in a Bayesian joint inversion to retrieve a series of 1D shear-wave velocity models, which are then interpolated to build a 3D model of the region. Our results display clear contrasts in the oceanic region across the border of the strike-slip fault system San Sebastian - El Pilar as well as a high velocity region that corresponds well with the continental craton of southeastern Venezuela. We resolve known geological features in our new model, including the Espino Graben and the Guiana Shield provinces, and provide new information about their crustal structures. Furthermore, we image the difference in the crust beneath the Maturin and Guárico Sub-Basin.

Integrated Seismic Program (ISP) is a graphical user interface designed to facilitate and provide a user-friendly framework for performing diverse common and advanced tasks in seismological research. ISP is composed of five main modules for earthquake location, time–frequency analysis and advanced signal processing, implementation of array techniques to estimate the slowness vector, seismic moment tensor inversion, and receiver function computation and analysis. In addition, several support tools are available, allowing the user to create an event database, download data from International Federation of Digital Seismograph Networks services, inspect the background noise, and compute synthetic seismograms. ISP is written in Python3, supported by several open-source and/or publicly available tools. Its modular design allows for new features to be added in a collaborative development environment.

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<p>Integrated Seismic Program (ISP) is a graphical user interface designed to facilitate and provide a user‐friendly framework for performing diverse common and advanced tasks in seismological research. ISP is composed of six main modules for earthquake location, time–frequency analysis and advanced signal processing, implementation of array techniques, seismic moment tensor inversion, receiver function computation and and a new module for ambient noise tomography.</p><p>Recently the Ambient Noise Tomography module has been upgraded with a tool specifically designed to synchronize Ocean Bottom Seismometers (OBSs) and to denoise the OBSs seismogram of the vertical component from tilt and compliance noise. The new tool has extensively been tested with data from UPFLOW project (https://upflow-eu.github.io).</p><p>In addition, several support tools are available, allowing the user to create an event database, download data from International Federation of Digital Seismograph Networks services, inspect the background noise, and compute synthetic seismograms.</p><p>ISP is written in Python3, supported by several open‐source and/or publicly available tools. Its modular design allows for new features to be added in a collaborative development environment.</p>