Search

High-resolution topographic modeling has become more accessible due to the development of structure from motion (SfM)-image-matching algorithms in digital photogrammetry. Large archival databases of historical aerial photographs are available in university, public, and government libraries, commonly as paper copies. The photographs can be in poor condition (i.e., deformed by humidity, scratched, or annotated). In addition, the negatives, as well as metadata, may be missing. Processing such photographs using classic stereo-photogrammetry is difficult and, in many instances, impossible. SfM can be applied to these photosets to access the valuable archive of geomorphic changes over the past century. In this paper, we illustrate the utility of the SfM technique using 568 digitized vertical aerial photographs of Mount Meager volcano, located in southwestern British Columbia, Canada. We use the aerial photographs, which span the period from 1947 to 2006, to track glaciers and glacier-landslide interactions on the volcano. Over this period, glaciers have thinned and retreated, interrupted by minor advances in the 1960s and 1970s. Landslides are frequent on the volcano and contribute to debris cover on the glaciers affecting the ablation process. SfM processing of the aerial photographs allowed us to unlock geomorphic information and reconstruct landscape change that would otherwise have been impossible. The results from SfM provide a visually effective way of presenting landscape change to a broad public audience, as a form of virtual geoheritage. The approach can thus be broadly applied in scientific and professional practices for improving land planning and hazard management. Key words: historical aerial photographs, structure from motion, glacier change, landslides, debris-covered glaciers. La modelisation topographique de haute resolution est devenue plus accessible en raison du developpement d'algorithmes de jumelage d'images de type << structure from motion >> (SfM, structure acquise a partir d'un mouvement) en photogrammetrie numerique. D'imposantes bases de donnees d'archives de photographies aeriennes sont disponibles dans les bibliotheques universitaires, publiques et gouvernementales, generalement en version papier. Ces photographies peuvent etre en mauvais etat (c.-a-d., deformees par l'humidite, egratignees ou annotees). En outre, des negatifs, ainsi que des metadonnees, peuvent manquer a l'appel. Le traitement de telles photographies par stereophoto-grammetrie classique est difficile, voire impossible dans bien des cas. La SfM peut etre appliquee a ses ensembles de photos pour acceder a l'important registre de changements geomorphologiques durant le siecle passe qu'ils renferment. Nous illustrons l'utilisation de la methode SfM en utilisant 568 photographies aeriennes verticales numerisees du volcan du mont Meager, dans le sud-ouest de la Colombie-Britannique (Canada). Nous utilisons les photographies aeriennes, qui couvrent la periode de 1947 a 2006, pour suivre les glaciers et les interactions entre glaciers et glissements de terrain sur le volcan. Cette periode est marquee par l'amincissement et le retrait des glaciers, interrompus par des avancees mineures dans les annees 1960 et 1970. Les glissements de terrain sont frequents sur le volcan et participent a l'accumulation d'un couvert de debris sur les glaciers qui influence le processus d'ablation. Le traitement SfM des photographies aeriennes nous a permis d'extraire de l'information geomorphologique et de reconstituer les changements du paysage, ce qui n'aurait pas ete possible autrement. Les resultats de SfM offrent un moyen visuellement efficace de presenter des modifications du paysage au grand public, comme geopatrimoine virtuel. L'approche peut ainsi etre appliquee largement dans les domaines scientifique et professionnel pour ameliorer l'amenagement du territoire et la gestion des risques. [Traduit par la Redaction] Mots-cles : photographies aeriennes passees, << structure from motion >>, modification de glaciers, glissements de terrain, glaciers couverts de debris., Introduction Reconstructions of geomorphic change over time are fundamental in many landform and natural hazard studies. Such landscape reconstructions are essential for following the evolution of features that might cause [...]

The Chiusella Valley (NW Italian Alps) is a key area for both the history of the alpine orogeny and its environmental context. It presents major structural features (including the Traversella neoalpine intrusion and a section of the Insubric line) and evidence of past climate changes in the region. Even if the Chiusella Valley was previously renowned for mining activities and most recently considered an alpine rural area with minor tourist attractions, its important geoheritage could offer alternatives to traditional mountain activities, which are facing adversity from increasing temperatures. This paper emphasises the role of geotourism in both enhancing sustainable development and raising awareness of climate change. For this purpose, the geodiversity of the Chiusella Valley has been analysed and several geosites have been identified. The research methodology includes field surveys, analysis of an existing educational activities and scientific literature, and assessment of geosites by quantitative analysis of five groups of indicators, including scientific, cultural, and educational values. The geosite selection within the Chiusella Valley reveals memories of past and present climate changes but also supports the development of targeted geotourism activities in the area. Additionally, a specific location has been identified for hosting indoor activities showcasing climate change action. These valuable contributions to sustainable geotourism provide opportunities for exploring the Alps in the vicinity of the Po Plain urban areas, while minimizing the environmental impact and facilitating educational activities on geodiversity and geoheritage. [ABSTRACT FROM AUTHOR]

Different carbonates have been detected on Ceres, and their abundance and spatial distribution have been mapped using a visible and infrared mapping spectrometer (VIR), the Dawn imaging spectrometer. Carbonates are abundant and ubiquitous across the surface, but variations in the strength and position of infrared spectral absorptions indicate variations in the composition and amount of these minerals. Mg-Ca carbonates are detected all over the surface, but localized areas show Na carbonates, such as natrite (Na2CO3) and hydrated Na carbonates (for example, Na2CO3·H2O). Their geological settings and accessory NH4-bearing phases suggest the upwelling, excavation, and exposure of salts formed from Na-CO3-NH4-Cl brine solutions at multiple locations across the planet. The presence of the hydrated carbonates indicates that their formation/exposure on Ceres' surface is geologically recent and dehydration to the anhydrous form (Na2CO3) is ongoing, implying a still-evolving body.

The dwarf planet Ceres is known to host a considerable amount of water in its interior, and areas of water ice were detected by the Dawn spacecraft on its surface. Moreover, sporadic water and hydroxyl emissions have been observed from space telescopes. We report the detection of water ice in a mid-latitude crater and its unexpected variation with time. The Dawn spectrometer data show a change of water ice signatures over a period of 6 months, which is well modeled as ~2-km2 increase of water ice. The observed increase, coupled with Ceres' orbital parameters, points to an ongoing process that seems correlated with solar flux. The reported variation on Ceres' surface indicates that this body is chemically and physically active at the present time.

Italian teams have been involved many times in Space Weather observational campaigns from space and from the ground, contributing in the advancing of our knowledge on the properties and evolution of the related phenomena. Numerous Space Weather forecasting and now-casting modeling efforts have resulted in a remarkable add-on to the overall progress in the field, at both national and international level. The Italian Space Agency has participated several times in space missions with science objectives related to Space Weather; indeed, an important field for the Italian scientific and industrial communities interested in Heliophysics and Space Weather, is the development of new instrumentation for future space missions. In this paper, we present a brief state-of-the-art in Space Weather science in Italy and we discuss some ideas on a long-term plan for the support of future scientific research in the related disciplines. In the context of the current roadmap, the Italian Space Agency aims to assess the possibility to develop a national scientific Space Weather data centre to encourage synergies between different science teams with interest in the field and to motivate innovation and new mission concept development. Alongside with the proposed recommendations, we also discuss how the Italian expertise could complement international efforts in a wider international Space Weather context.