adrian.marfer
@uva.es
Department of Geography
University of Valladoli, Spain
Scopus Publications
Scopus Publications
A. Martínez‐Fernández, E. Serrano, J. J. de Sanjosé, M. Gómez‐Lende, M. Sánchez‐Fernández, J. I. López‐Moreno, I. Rico, and A. Pisabarro
Wiley
AbstractSmall glaciers are one of the best indicators of climatic variations and their short‐term effects. Located in the Spanish Pyrenees, the Maladeta is one of these glaciers. Its systematic observation began in the 1980s, being one of the few Pyrenean glaciers with a tongue‐shaped front. This study presents the evolution of the Maladeta glacial tongue over a decade (2010–2020) through multiple geomatic techniques. Surveys have ranged from Total Stations and Global Navigation Satellite System devices to massive data capture techniques such as Terrestrial Laser Scanners or Unmanned Aerial Vehicles photogrammetry. The aim is to analyze in detail the loss of surface area and thickness of the glacier and its transition from being a glacier with a tongue partially determined by climate to a topoclimatically determined cirque glacier. The results reveal a tongue retreat of over 5 m/yr and area losses of over 0.2 ha/yr, along with ice thickness and volume losses of −1.7 m/yr and over −21 × 103 m3/yr, respectively. If this trend continues, the tongue, and possibly the Maladeta glacier, could disappear by the end of the 2030s.
Isabel Hernando-Alonso, Davinia Moreno, Ana Isabel Ortega, Alfonso Benito-Calvo, María Jesús Alonso, Josep María Parés, Adrián Martínez-Fernández, Eudald Carbonell, and José María Bermúdez de Castro
Elsevier BV
Adrián Martínez-Fernández, Enrique Serrano, Alfonso Pisabarro, Manuel Sánchez-Fernández, José Juan de Sanjosé, Manuel Gómez-Lende, Gizéh Rangel-de Lázaro, and Alfonso Benito-Calvo
MDPI AG
The detailed description of processing workflows in Structure from Motion (SfM) surveys using unmanned aerial vehicles (UAVs) is not common in geomorphological research. One of the aspects frequently overlooked in photogrammetric reconstruction is image characteristics. In this context, the present study aims to determine whether the format or properties (e.g., exposure, sharpening, lens corrections) of the images used in the SfM process can affect high-detail surveys of complex geometric landforms such as rock glaciers. For this purpose, images generated (DNG and JPEG) and derived (TIFF) from low-cost UAV systems widely used by the scientific community are applied. The case study is carried out through a comprehensive flight plan with ground control and differences among surveys are assessed visually and geometrically. Thus, geometric evaluation is based on 2.5D and 3D perspectives and a ground-based LiDAR benchmark. The results show that the lens profiles applied by some low-cost UAV cameras to the images can significantly alter the geometry among photo-reconstructions, to the extent that they can influence monitoring activities with variations of around ±5 cm in areas with close control and over ±20 cm (10 times the ground sample distance) on surfaces outside the ground control surroundings. The terrestrial position of the laser scanner measurements and the scene changing topography results in uneven surface sampling, which makes it challenging to determine which set of images best fit the LiDAR benchmark. Other effects of the image properties are found in minor variations scattered throughout the survey or modifications to the RGB values of the point clouds or orthomosaics, with no critical impact on geomorphological studies.
Alfonso Benito-Calvo, Davinia Moreno, Toshiyuki Fujioka, Gloria I. López, Fidel Martín-González, Adrián Martínez-Fernández, Isabel Hernando-Alonso, Theodoros Karampaglidis, José María Bermúdez de Castro, and Francisco Gutiérrez
Elsevier BV
Francisco Gutiérrez, Alfonso Benito-Calvo, Domingo Carbonel, Gloria Desir, Jorge Sevil, Jesús Guerrero, Adrián Martínez-Fernández, Theodoros Karamplaglidis, Ángel García-Arnay, and Ivan Fabregat
Elsevier BV
Gizéh Rangel-de Lázaro, Adrián Martínez-Fernández, Armando Rangel-Rivero, and Alfonso Benito-Calvo
Universitat Politecnica de Valencia
<p class="VARAbstract">During the 19<sup>th</sup> and 20<sup>th</sup> centuries, numerous museums, scientific societies, and royal academies were founded in Europe and America. In this scenario, the Anthropological Museum Montané was founded in Havana, Cuba. Its collection has grown over the years, thanks to researchers, antiquarians, and amateurs. Since its foundation, the Museum Montané has become an essential institution for anthropological and archaeological research in the region. Nowadays, the Museum Montané, like other museums in developing countries, faces a challenge in the introduction of state-of-the-art technologies to digitizing exhibits and the creation of innovative projects to attract visitors. The current possibilities of virtualization of cultural heritage using digital technologies have a favorable impact on the preservation, access, and management of museum collections. The use of three-dimensional (3D) models fosters engagement with visitors, stimulates new forms of learning, and revalorizes the exhibits. In the current study, we use a hand-held structured light scanner to create 3D reality-based models of pre-Columbian crania from the Caribbean and South American collection of the Anthropological Museum Montané. The resulting 3D models were used for producing 3D printing replicas and animated videos. The 3D resources derived will encourage new knowledge through research, and provide broader access to these pre-Columbian crania collection through learning and outreach activities. The significance of digitizing these specimens goes beyond the creation of 3D models. It means protecting these fragile and valuable collections for future generations. The methodology and results reported here can be used in other museums with similar collections to digitally document, study, protect, and disseminate the archaeological heritage. Going forward, we seek to continue exploring the application of novel methods and digital techniques to the study of the pre-Columbian crania collections in Latin American and the Caribbean area.</p><p class="VARAbstractHeader">Highlights:</p><ul><li><p>A hand-held structured light scanner was used to acquire 3D reality-based models of pre-Columbian crania. The 3D models resulting were used for 3D printing replicas and 3D animations.</p></li><li><p>This study provides unprecedented 3D reconstructions of pre-Columbian crania in the Caribbean area, and new 3D reconstructions of artificially deformed crania from South America.</p></li><li><p>The 3D resources created will encourage new knowledge through research, and provide broader access to these pre-Columbian crania collection through learning and outreach activities.</p></li></ul>
Adrián Martínez-Fernández, Alfonso Benito-Calvo, Isidoro Campaña, Ana Isabel Ortega, Theodoros Karampaglidis, José María Bermúdez de Castro, and Eudald Carbonell
Elsevier BV
Abstract The advantages of active massive data capture devices such as LiDAR (Light Detection And Ranging) in the creation of high-resolution topographic models have been well known for years. They have been widely applied to the documentation of cultural heritage since the beginning of the 21st century. As LiDAR devices, terrestrial laser scanning (TLS) systems, or ground-based LiDAR, have shown themselves since then to have a multitude of applications and have proven clear advantages over classical survey methods. Nevertheless, few attempts have been made to use this method on Paleolithic archaeological excavations beyond one-time 3D reconstructions, which are mainly focused on forming a basis for conducting other studies. Since the excavation process involves the irreversible modification or destruction of deposits and spatial relationships that will not be reproduced again, the comprehensive reconstruction of excavation surfaces represents a fundamental issue for the research, dissemination, and conservation of Paleolithic sites. Through this work, we show the techniques and potential of the sequential geometric documentation of Paleolithic site excavations using TLS systems on the Sierra de Atapuerca Railway Trench sites (Gran Dolina, Galeria and Sima del Elefante). Related to this sequential documentation, a case of application and a storage concept in Paleolithic archaeology is presented. As an application, the models were used to monitor the excavation surface changes and physical damage to excavation sections occurring during the last seven years. As a concept, multi-temporal models and derived information were stored in a database from which their design is displayed, the 4D (i.e., time dimension added to the three-dimensional spatial data) database. The results reveal TLS systems, 4D data, and 4D databases as efficient methods for providing detailed reconstructions, exhaustive change models, and storage of paleosurfaces, which could be applied also to other multi-annual excavation sites.
Enrique Serrano, José Juan Sanjosé‐Blasco, Manuel Gómez‐Lende, Juan Ignacio López‐Moreno, Alfonso Pisabarro, and Adrián Martínez‐Fernández
Wiley
The periglacial belt is located in the highest parts of temperate mountains. The balance between mean air and ground temperatures and the presence of water determine the effectiveness of periglacial processes related to permafrost, the active layer or seasonally frozen ground (SFG). This study combines thermal and geomorphological data obtained in four Pyrenean massifs (Infierno‐Argualas, Posets, Maladeta and Monte Perdido) to improve knowledge on the occurrence and distribution of frozen ground. The methodology used is based on the study of landforms as frozen ground indicators, mapping processes, ground temperature analysis, basal temperature of snow, thermal mapping and geomatic surveys on rock glaciers and protalus lobes. In the Pyrenean high mountain areas the lower limit of frozen ground is at ~2,650m a.s.l., possible permafrost appears above 2,650m a.s.l. on north‐ and south‐facing slopes, and probable permafrost is dominant above 2,900m a.s.l. Unfrozen ground with cold‐associated geomorphological processes reach 2,900m a.s.l. and unfrozen and frozen ground distribution points to a patchy pattern throughout the periglacial belt. The most widespread frozen grounds are SFG. The thermal data, mean annual ground temperature, cold season temperatures, bottom temperature snow measurements, freeze/thaw cycles and distribution of landforms permit the establishment of a periglacial land system divided into three main belts: infraperiglacial, middle periglacial and supraperiglacial. The large number of processes and landforms that are involved and their altitudinal and spatial organization make up a complex environment that determines the geoecological dynamics of high mountain areas.
A. Martínez-Fernández, E. Serrano, J. J. Sanjosé, M. Gómez-Lende, A. Pisabarro, and M. Sánchez
Copernicus GmbH
<p><strong>Abstract.</strong> Rock glaciers are one of the most important features of the mountain permafrost in the Pyrenees. La Paúl is an active rock glacier located in the north face of the Posets massif in the La Paúl glacier cirque (Spanish Pyrenees). This study presents the preliminary results of the La Paúl rock glacier monitoring works carried out through two geomatic technologies since 2013: Global Navigation Satellite System (GNSS) receivers and Terrestrial Laser Scanning (TLS) devices. Displacements measured on the rock glacier surface have demonstrated both the activity of the rock glacier and the utility of this equipment for the rock glaciers dynamic analysis. The glacier has exhibited the fastest displacements on its west side (over 35&amp;thinsp;cm&amp;thinsp;yr<sup>&amp;minus;1</sup>), affected by the Little Ice Age, and frontal area (over 25&amp;thinsp;cm&amp;thinsp;yr<sup>&amp;minus;1</sup>). As an indicator of permafrost in marginal environments and its peculiar morphology, La Paúl rock glacier encourages a more prolonged study and to the application of more geomatic techniques for its detailed analysis.</p>
Francisco Gutiérrez, Alfonso Benito-Calvo, Domingo Carbonel, Gloria Desir, Jorge Sevil, Jesús Guerrero, Adrián Martínez-Fernández, Theodoros Karamplaglidis, Ángel García-Arnay, and Ivan Fabregat
Elsevier BV
Abstract The need to apply sinkhole remediation and monitoring programs is increasing, concurrently with the rising engineering impacts of sinkholes in many regions. However, there is a significant gap in the scientific literature regarding the assessment of the performance of remedial works through subsidence monitoring. Monitoring techniques have experienced significant advances in the last few years thanks to the advent of new technologies. This work presents a review of sinkhole monitoring methods and discusses some practical considerations about their capabilities and limitations. It also documents a monitoring program (high-precision leveling and terrestrial laser scanner) and the concurrent remedial works (cement-based and polyurethane grouting) carried out in a highly active sinkhole that affects a flood-control dike and the adjacent village of Alcala (NE Spain). The subsidence activity in the sinkhole is characterised by progressive sagging and the development of catastrophic nested collapses. Monitoring data reveal subsidence expansion and acceleration in the sector of the dike treated by polyurethane grouting above the main cavities. In contrast, subsequent cement-based grouting of the large cavities significantly reduced subsidence rates. Displacement data also indicate substantial subsidence enhancement following flood recession and the associated water table drop (buoyancy loss). This case study illustrates that high-precision leveling and terrestrial laser scanning are adequate complementary methods for monitoring specific sinkholes, characterised by very high accuracy and detailed spatial resolution, respectively.
Alfonso Benito-Calvo, Alyssa N. Crittenden, Sarah V. Livengood, Laura Sánchez-Romero, Adrián Martínez-Fernández, Ignacio de la Torre, and Michael Pante
Elsevier BV
Abstract Surface morphometry comprises a relevant set of techniques that provide objective tools to identify, map, and understand use wear patterns in stone tools. Thus far, these techniques have been applied mainly to 2D or 2.5D data, but their application to 3D 360° data is promising and still underdeveloped. Here, we apply new 3D techniques to calculate morphometric variables and to analyse surficial features and changes in pounding stone tools used for baobab processing among Hadza foragers of Tanzania. Baobab pounding stones were collected after use by Hadza foragers for processing the plant food and then 3D point clouds were acquired from laser scanners and SfM photogrammetry. Morphometry was conducted directly on 3D point clouds to avoid time-consuming and surface modifications related to more complex 3D data, such as meshing. Several morphometric variables were computed for the complete pieces (360° sphere) providing fast and accurate data to identify the detailed morphometric features of the artefacts. Additionally, stone surface changes due to baobab processing were measured by comparing the stone surface before and after use, thus enabling calculation of spatial abrasion patterns. Data were interpreted using multivariate exploratory statistical analysis. Differences in the effect of processing on surface morphology are likely explained by variations in raw source material and use. Results suggest that the traces produced by baobab processing on stone tools should be detectable in the archaeological record.
Alfonso Benito-Calvo, Francisco Gutiérrez, Adrián Martínez-Fernández, Domingo Carbonel, Theodoros Karampaglidis, Gloria Desir, Jorge Sevil, Jesús Guerrero, Ivan Fabregat, and Ángel García-Arnay
MDPI AG
This work explores, for the first time, the application of a Terrestrial Laser Scanner (TLS) and a comparison of point clouds in the 4D monitoring of active sinkholes. The approach is tested in three highly-active sinkholes related to the dissolution of salt-bearing evaporites overlain by unconsolidated alluvium. The sinkholes are located in urbanized areas and have caused severe damage to critical infrastructure (flood-control dike, a major highway). The 3D displacement models derived from the comparison of point clouds with exceptionally high spatial resolution allow complex spatial and temporal subsidence patterns within one of the sinkholes to be resolved. Detected changes in the subsidence activity (e.g., sinkhole expansion, translation of the maximum subsidence zone, development of incipient secondary collapses) are related to potential controlling factors such as floods, water table changes or remedial measures. In contrast, with detailed mapping and high-precision leveling, the displacement models, covering a relatively short time span of around 6 months, do not capture the subtle subsidence (<0.6–1 cm) that affects the marginal zones of the sinkholes, precluding precise mapping of the edges of the subsidence areas. However, the performance of TLS can be adversely affected by some methodological limitations and local conditions: (1) limited accuracy in large investigation areas that require the acquisition of a high number of scans, increasing the registration error; (2) surface changes unrelated to sinkhole activity (e.g., vegetation, loose material); (3) traffic-related vibrations and wind blast that affect the stability of the scanner.