Abstract:The aim of this article is to provide a qualitative and quantitative description of Lower-Upper Cretaceous detrital rocks (Escucha and Utrillas sandstones) in order to explore their potential use as CO 2 reservoirs based on their petrographic and petrophysical characteristics. Optical microscopy (OpM) and scanning electron microscopy (SEM) aided by optical image analysis (OIA) were used to get qualitative and quantitative information about mineralogy, texture and pore network structure. Complementary analyses by X-ray fluorescence (XRF) and X-ray diffraction (XRD) were performed to refine the mineralogical information and to obtain whole rock geochemical data. Furthermore, mercury injection capillary pressure analysis (MICP), the gas permeameter test (GPT) and the hydraulic test (HT) were applied to assess the potential storage capacity and the facility of fluid flow through the rocks. Both of these factors have an outstanding importance in the determination of CO 2 reservoir potential. The applied petrophysical and petrographic methods allowed an exhaustive characterization of the samples and a preliminary assessment of their potential as a CO 2 reservoir. The studied conglomerates and sandstones have a porosity range of 8-26% with a dominant pore size range of 80-500 µm. The grain skeleton consists of quartz (95%), very minor potassium feldspars (orthoclase) and a small amount of mica (muscovite and chlorite). According to these preliminary results, among the studied varieties, the Escucha sandstones have the most favorable properties for CO 2 geological storage at the rock matrix scale.

<p>Ground displacements associated to landslides can be analysed by means of geological, geotechnical, topographic and remote sensing techniques. In this work different classical topographic techniques are combined with a satellite based remote sensing technique: Differential SAR Interferometry (DInSAR). The topographic techniques provide precise measurements on a set of points strategically located for each landslide. The DInSAR technique provides a more opportunistic set of points, usually denser than topographic techniques, providing key information on the area of influence of the movement and its potential impact on the surroundings. The combination of both approaches provides a complementary set of measurements useful to properly understand the landslide mechanics. The area of study is Tazones Lighthouse sector (43º 32’ 54’’N, 5º 23’ 57’’W), located on a coastal cliff in north Asturias (N Spain), where there is an important active mass movement.</p><p>The used procedure consisted in the following steps: a) Processing of Envisat ASAR satellite data from 2002 to 2012 to obtain the deformation velocity map of the zone of interest thorough the ESA G-POD service (European Space Agency Grid Processing On Demand); b) Processing of the period 2014-2019 with Sentinel-1 data to obtain the Deformation time series and the deformation velocity map with the PSIG software (developed by the Geomatics Division of the CTTC); c) Integration, combination and comparison by a Geographical Information System (GIS) of the satellite results with topographic data obtained from 2018 to 2019 by means of standard techniques (theodolite, feno survey markers and control points); d) Analysis and interpretation of the results taken into account geological-geomorphological data available.</p><p>The results of this study show different velocity ratios in the Area of Interest (AoI), from mm/year to m/year, which are consistent with the ground measurements. Therefore, the work demonstrated the potentials of combining different geodetic techniques to infer information about landslides processes and the usefulness of the DInSAR for the control of the mass movement, whose fast evolution makes it difficult the topographic work due to the changes in the relief and the loss of several feno survey markers.</p>

<p>Landslides are one of the most common and dangerous threats in the world that generate considerable damage and economic losses. The aim of this study is to analyse the suitability of using the ESA G-POD (European Space Agency Grid Processing On Demand) environment to detect landslide incidence.</p><p>This free service allows to gain Mean Deformation Maps (mm/year and cm/year) by means of P-SBAS (Parallel-Small Baseline Subset) method, which is a kind of A-DInSAR (Advanced-Differential SAR Interferometry) technique.</p><p>The study area is in the Northwest of Spain, where there are and have been some significant well-known active landslides. ENVISAT ASAR satellite data collected from 2003 to 2010, have been contrasted with the slope instabilities inventory of Asturias (BAPA: <em>Base de datos de Argayos del Principado de Asturias</em> - Principality of Asturias Landslide Database), from 2003 to 2010. Afterwards, a new check with instability data registered in BAPA dataset from 2010 to 2017 has been done.</p><p>A-DInSAR and BAPA data have been jointly integrated and examined in a GIS. The results obtained indicate that there is consistency between both types of data. In addition, this research has been useful to highlight the G-POD free service as a reliable, economic and adequate tool to analyse movements of terrain during time periods of several years in the North of Spain.</p>

<p>In this work, the A-DInSAR techniques are applied in a mountainous area located in the Central South of Asturias (N Spain), where there are significant landslide and subsidence phenomena. The main aim of this study is detecting and analysing ground deformations associated to slope instabilities and subsidence processes. For this, 113 SAR images, provided by Sentinel-1A/B between January 2018 and February 2020, were acquired and processed by means of PSIG software (developed by the Geomatics Division of the CTTC). The results show a velocity range between -18.4 and 10.0 mm/year, and minimum and maximum accumulated ground displacements of -35.0 and 17.5 mm. This study has made possible to differentiate local sectors with recent deformation related to landslide incidence, urban/mining subsidence, and land recuperation due to aquifer recharge. This work corroborates the reliability and usefulness of the A-DInSAR processing as a powerful tool in the study and analysis of geological hazards on regional and local scales using Sentinel-1 data collection, showing also the high difficulty of processing mountainous areas with few urban sectors.</p>