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Investigating the dynamics of liquid iron at the top of the core requires an inversion process from magnetic field measurements. Due to possible leakage, traditional spectral techniques are not optimal for regional investigations or studies of Secular Variation (first time derivative of magnetic field, SV) on short-time periods. Improved data coverage and quality from satellite missions have provided insight into short-period dynamics (such as jerks and waves), and improved understanding of localised features. However, there continues to be a need for new techniques for better spatio-temporal models of flow motions at the top of the core, especially for regional investigations.The aim of this work is to investigate regional dynamics at the Core-Mantle Boundary (CMB) using the SOLA (Subtractive Optimally Localised Averages) methodology. This method allows us to create point estimates of radial field SV at the CMB by considering global satellite measurements. The SOLA methodology allows for a local estimate of radial field SV at any desired location directly at the CMB, which opens the way to investigations of regional dynamics. Producing localised-average estimates at the CMB bypasses many problems encountered when using only a subset of magnetic satellite data, downward continuing data, and models based on spherical harmonics.Finally, we discuss how the SOLA methodology can be incorporated into the PyGeodyn code to produce core flow models. This approach can provide additional information on wave-like flow motions at the top of the Earth’s core where these are most prominent, and permits new investigations of shorter period phenomenon.&nbsp, The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

The Earth’s interior, particularly the Earth’s fluid outer core, possesses a broad dynamics of processes involving mass variations. Theoretical models predict variations of the gravity field at low degrees and at inter-annual / decadal time scales. These include dynamic pressure changes at the Core Mantle Boundary (CMB) associated with core flows reconstructed from geomagnetic observations and reorientation of the inner core controlled by gravitational coupling with the mantle. The hypothetical effects due to some dissolution/crystallization at the CMB introduce a time-varying roughness of the interface. Taking into account these considerations, for the first time, we investigate the density and pressure changes obtained from magneto-hydro-dynamics (MHD) simulations that reproduce geomagnetic jerks.Besides the geomagnetic information, we also are interested in exploiting long series of gravity measurements. The time-variable Earth’s gravity field is measured by satellite missions such as GRACE and GRACE Follow-On and by Satellite Laser Ranging (SLR). These products enable to study continental hydrology, oceanic and atmospheric loading, post-glacial rebound, glaciers, earthquakes and other phenomena that involve mass variations. The comparison of GRACE and SLR gravity field variations with Earth’s core predicted signals gives new inputs on parameters of the Earth’s core processes. This study provides new upper-bound values for pressure anomalies at the CMB and angle of reorientation for the inner core., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

On the timescales of mantle convection (~100 Myrs), downwelling mantle flows due to buoyancy-driven flows depress the core-mantle boundary (CMB) into the outer core (OC) creating a dynamic topography. Seismological studies have suggested that the peak-to-peak amplitudes are less than 10 km. If the solid grain boundaries of mantle silicates and oxides are sufficiently wetted, percolation of liquid iron alloy into the matrix can create an interconnected network to form a metal-silicate mush at CMB topography lows. Since timescales of large-scale flows at the top of the OC are much smaller than viscous compaction timescales of the silicate matrix in the mushy layer, hydrodynamic and magnetic pressure gradients in the OC can drive Darcy flow inside the porous region. This will not only create an electrically conducting region at the solid side of the CMB that distorts the magnetic field, but also produce stronger mechanical coupling within the mushy layer via viscous stresses between the matrix and fluid. These combined effects can result in torques at the CMB that transfers angular momentum between the mantle and OC, thus affecting variations in the length of day. Lastly, flows in the mushy layer facilitate chemical and isotopic exchange between the liquid iron and silicate matrix which has implications on the chemical evolution of the Earth. We will present a study that analyses the pressure torques at the CMB due to the presence of a porous layer, and how surface core flows can be affected by permeability and porosity of the layer., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Trabajo presentado en la European Geosciences Union General Assembly, celebrada en Viena (Austria), del 23 al 28 de abril de 2017, EPOS, the European Plate Observing System, is a long-term plan to facilitate the integrated use of data, data products, software and services, available from distributed Research Infrastructures (RI), for solid Earth science in Europe. Indeed, EPOS integrates a large number of existing European RIs belonging to several fields of the Earth science, from seismology to geodesy, near fault and volcanic observatories as well as anthropogenic hazards. The EPOS vision is that the integration of the existing national and trans-national research infrastructures will increase access and use of the multidisciplinary data recorded by the solid Earth monitoring networks, acquired in laboratory experiments and/or produced by computational simulations. The establishment of EPOS will foster the interoperability of products and services in the Earth science field to a worldwide community of users. Accordingly, the EPOS aim is to integrate the diverse and advanced European Research Infrastructures for solid Earth science, and build on new e-science opportunities to monitor and understand the dynamic and complex solid-Earth System. One of the EPOS Thematic Core Services (TCS), referred to as Satellite Data, aims at developing, implementing and deploying advanced satellite data products and services, mainly based on Copernicus data (namely Sentinel acquisitions), for the Earth science community. This work intends to present the technological enhancements, fostered by EPOS, to deploy effective satellite services in a harmonized and integrated way. In particular, the Satellite Data TCS will deploy five services, EPOSAR, GDM, COMET, 3D-Def and MOD, which are mainly based on the exploitation of SAR data acquired by the Sentinel-1 constellation and designed to provide information on Earth surface displacements. In particular, the planned services will provide both advanced DInSAR products (deformation maps, velocity maps, deformation time series) and value-added measurements (source model, 3D displacement maps, seismic hazard maps). Moreover, the services will release both on-demand and systematic products. The latter will be generated and made available to the users on a continuous basis, by processing each Sentinel-1 data once acquired, over a defined number of areas of interest; while the former will allow users to select data, areas, and time period to carry out their own analyses via an on-line platform. The satellite components will be integrated within the EPOS infrastructure through a common and harmonized interface that will allow users to search, process and share remote sensing images and results. This gateway to the satellite services will be represented by the ESA- Geohazards Exploitation Platform (GEP), a new cloud-based platform for the satellite Earth Observations designed to support the scientific community in the understanding of high impact natural disasters. Satellite Data TCS will use GEP as the common interface toward the main EPOS portal to provide EPOS users not only with data products but also with relevant processing and visualisation software, thus allowing users to gather and process on a cloud-computing infrastructure large datasets without any need to download them locally