ALBERT

Description: We provide a present-day surface-kinematics model for the Alpine region and surroundings based on a high-level data analysis of about 300 geodetic stations continuously operating over more than 12 years. This model includes a deformation model, a continuous surface-kinematic (velocity) field, and a strain field consistently assessed for the entire Alpine mountain belt. Special care is given to the use of the newest GNSS processing standards to determine high-precise 3D station coordinates. The coordinate solution refers to the reference frame IGb08, epoch 2010.0. The mean precision of the station positions at the reference epoch is ±1.1mm in N and E and ±2.3mm in height. The mean precision of the station velocities is ±0.2mm/a in N and E and ±0.4mm/a in the height. The deformation model is derived from the pointwise station velocities using a geodetic least-squares collocation approach with empirically determined covariance functions. According to our results, no significant horizontal deformation is detected in the Western Alps, while across the Southern and Eastern Alps the deformation vectors describe a progressive eastward rotation toward Pannonia. This kinematic pattern makes also evident an increasing magnitude of the deformation from 0.1mm/a in the western part of Switzerland up to about 1.5mm/a in the Austrian Alps. The largest shortenings are observed along the southern front of the Eastern Alps (in the northern area of the Venetian-Friuli Basin) and in the northern part of the Apennine Peninsula, where they reach 2mm/a and 3 mm/a, respectively. The averaged accuracy of the horizontal deformation model is ±0.2mm/a. Regarding the vertical kinematics, our results clearly show an still on-going averaged uplift of 1.8mm/a of the entire mountain chain, with exception of the southern part of the Western Alps, where no significant uplift (less than 0.5mm/a) is detected. The fastest uplift rates (more than 2mm/a) occur in the central area of the Western Alps, in the Swiss Alps and in the Southern Alps in the boundary region between Switzerland, Austria and Italy. The general uplift observed across the Alpine mountain chain decreases toward the outer regions to stable values between 0.0 and 0.5mm/a and, in some cases, to subsidence like in the Liguro-Provençal and Vienna Basins, where vertical rates of −0.8mm/a and −0.3mm/a are observed respectively. In the surroundings, three regional subsidence regimes are identified: the Rhone-Bresse Graben with −0.8mm/a, the Rhine Graben with −1.3mm/a, and the Venetian-Friuli Basin with −1.5mm/a. The estimated uncertainty of our vertical motion model across the Alpine mountain belt is about ±0.3mm/a. The strain field inferred from the deformation model shows two main contrasting strain regimes: shortening across the south-eastern front of the Alps and the northern part of the Dinarides, and extension in the Apennines. The pattern of the strain principal axes indicates that the compression directions are more or less perpendicular to the thrust belt fronts, reaching maximum values of 20x10−9a−1 in the Venetian-Friuli and Po Basins. Across the Alpine mountain belt, we observe a slight dilatation regime in the Western Alps, which smoothly changes to a contraction regime in West Austria and South Germany, reaching maximum shortening values of 6x10−9a−1 in the north-eastern Austria. The numerical results of this study are available at https://doi.pangaea.de/10.1594/PANGAEA.886889.

Description: We provide a present-day surface-kinematics model for the Alpine region and surroundings based on a high-level data analysis of about 300 geodetic stations continuously operating over more than 12 years. This model includes a deformation model, a continuous surface-kinematic (velocity) field, and a strain field consistently assessed for the entire Alpine mountain belt. Special care is given to the use of the newest Global Navigation Satellite Systems (GNSS) processing standards to determine high-precision 3-D station coordinates. The coordinate solution refers to the reference frame IGb08, epoch 2010.0. The mean precision of the station positions at the reference epoch is ±1.1 mm in N and E and ±2.3 mm in height. The mean precision of the station velocities is ±0.2 mm a−1 in N and E and ±0.4 mm a−1 in height. The deformation model is derived from the point-wise station velocities using a geodetic least-squares collocation (LSC) approach with empirically determined covariance functions. According to our results, no significant horizontal deformation is detected in the Western Alps, while across the Southern and Eastern Alps the deformation vectors describe a progressive eastward rotation towards Pannonia. This kinematic pattern also makes evident an increasing magnitude of the deformation from 0.1 mm a−1 in the western part of Switzerland up to about 1.3 mm a−1 in the Austrian Alps. The largest shortening is observed along the southern front of the Eastern Alps (in the northern area of the Venetian-Friuli Basin) and in the northern part of the Apennine Peninsula, where rates reach 2 and 3 mm a−1, respectively. The average accuracy of the horizontal deformation model is ±0.2 mm a−1. Regarding the vertical kinematics, our results clearly show an ongoing average uplift rate of 1.8 mm a−1 of the entire mountain chain, with the exception of the southern part of the Western Alps, where no significant uplift (less than 0.5 mm a−1) is detected. The fastest uplift rates (more than 2 mm a−1) occur in the central area of the Western Alps, in the Swiss Alps, and in the Southern Alps in the boundary region between Switzerland, Austria, and Italy. The general uplift observed across the Alpine mountain chain decreases towards the outer regions to stable values between 0.0 and 0.5 mm a−1 and, in some cases, to subsidence like in the Liguro-Provençal and Vienna basins, where vertical rates of −0.8 and −0.3 mm a−1 are observed, respectively. In the surrounding region, three regional subsidence regimes are identified: the Rhône-Bresse Graben with −0.8 mm a−1, the Rhine Graben with −1.3 mm a−1, and the Venetian-Friuli Basin with −1.5 mm a−1. The estimated uncertainty of our vertical motion model across the Alpine mountain belt is about ±0.3 mm a−1. The strain field inferred from the deformation model shows two main contrasting strain regimes: (i) shortening across the south-eastern front of the Alps and the northern part of the Dinarides and (ii) extension in the Apennines. The pattern of the principal strain axes indicates that the compression directions are more or less perpendicular to the thrust belt fronts, reaching maximum values of 20×10-9 a−1 in the Venetian-Friuli and Po basins. Across the Alpine mountain belt, we observe a slight dilatation regime in the Western Alps, which smoothly changes to a contraction regime in western Austria and southern Germany, reaching maximum shortening values of 6×10-9 a−1 in north-eastern Austria. The numerical results of this study are available at https://doi.pangaea.de/10.1594/PANGAEA.886889.

Description: The Land Use/Cover Area frame Survey (LUCAS) is an evenly spaced in situ land cover and land use ground survey exercise that extends over the whole of the European Union. LUCAS was carried out in 2006, 2009, 2012, 2015, and 2018. A new LUCAS module specifically tailored to Earth observation (EO) was introduced in 2018: the LUCAS Copernicus module. The module surveys the land cover extent up to 51 m in four cardinal directions around a point of observation, offering in situ data compatible with the spatial resolution of high-resolution sensors. However, the use of the Copernicus module being marginal, the goal of the paper is to facilitate its uptake by the EO community. First, the paper summarizes the LUCAS Copernicus protocol to collect homogeneous land cover on a surface area of up to 0.52 ha. Secondly, it proposes a methodology to create a ready-to-use dataset for Earth observation land cover and land use applications with high-resolution satellite imagery. As a result, a total of 63 364 LUCAS points distributed over 26 level-2 land cover classes were surveyed on the ground. Using homogeneous extent information in the four cardinal directions, a polygon was delineated for each of these points. Through geospatial analysis and by semantically linking the LUCAS core and Copernicus module land cover observations, 58 426 polygons are provided with level-3 land cover (66 specific classes including crop type) and land use (38 classes) information as inherited from the LUCAS core observation. The open-access dataset supplied with this paper (https://doi.org/10.6084/m9.figshare.12382667.v4 d'Andrimont, 2020) provides a unique opportunity to train and validate decametric sensor-based products such as those obtained from the Copernicus Sentinel-1 and Sentinel-2 satellites. A follow-up of the LUCAS Copernicus module is already planned for 2022. In 2022, a simplified version of the LUCAS Copernicus module will be carried out on 150 000 LUCAS points for which in situ surveying is planned. This guarantees a continuity in the effort to find synergies between statistical in situ surveying and the need to collect in situ data relevant for Earth observation in the European Union.