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We investigated the Late Pleistocene-Holocene crustal vertical movements off the coast of Marzamemi village in SE Sicily, Italy. By using a Synchronous Correlation Approach (SCA), we analysed terraced landforms that characterize a submerged sector within one of Southern Italy's most seismically active regions. In this area, the emerging portion of the NE-SW oriented bulge of the African foreland structurally shapes the coastal and marine regions off Marzamemi village. Based on a newly created 17 km2 high-resolution bathymetric map generated from a Multibeam Echosounder (MBES) survey conducted in June 2021, we identified and examined four main paleo-shorelines identifying four submerged terraces. Terraced landforms play a crucial role in reconstructing Quaternary glacial and interglacial stages, offering insights into associated sea level fluctuations. Through the application of the SCA, our goal is to refine the chronology of these recently mapped and submerged marine terraces off the Marzamemi village, thereby contributing to the calculation of associated rates of crustal vertical movements. We demonstrate that these rates persist constantly throughout the Late Pleistocene-Holocene epoch, suggesting overall tectonic stability, with a slight and likely local fault-related subsidence. We explore a few chronology scenarios, raising questions about whether these submerged marine terraces are indeed recording the Late Pleistocene-Holocene limit or not. This research contributes to a better understanding of the geological dynamics in this region and sheds light on the potential factors influencing coastal landscape development over time.

The BridgET Erasmus+ project (2021-1-IT02-KA220-HED-000027612) aims at filling the gap of information in the so-called white ribbon area, focusing on 3D geological mapping for a reliable integration of onshore and offshore multiscale geospatial datasets in selected coastal areas. The programme has been designed to develop innovative and inclusive learning and teaching activities through the organization of dedicated summer schools. Specifically, one of the main foci is the application of geospatial data acquisition and processing methods in order to generate seamless 3D models for coastal geohazard assessment. The second BridgET summer school was held in Catania and nearby areas from September 30th to October 11th, 2023. Here, we present preliminary results of an integrated multi-sensor dataset of Lachea Island. The result of this case study will be a seamless model, showing the island’s geomorphological variability from above to below the water surface. Offshore data was collected by Multibeam Echosounder (MBES) survey, covering a total area of about 0.33 km2 and obtaining a georeferenced point cloud with a resolution of about 580 points/m2 and a derived Digital Elevation Model of 1 m resolution. Near-surface remote sensing data was collected by Uncrewed Aerial Systems (UAS) in the form of both, structure-from-motion photogrammetry and LiDAR surveys, obtaining point clouds at a resolution of 225 and 50 points/m2, respectively. Lachea Island is part of the Cyclopean Archipelago. The “Lachea Island and Archipelago Integral Nature Reserve” was established in 1988, to conserve and protect fauna and flora from the supralittoral to the infralittoral zones. Due to its morphological setting, the area is subject to rockfalls and slope instability processes, which limit the accessibility for tourists. Geohazard characterization is therefore highly important, particularly in the view of risk assessment and mitigation measures.

Posidonia oceanica, seagrass endemic of the Mediterranean Sea, builds extensive meadows considered a form of Mediterranean bioconstruction that sustain a number of ecosystem services. However, these meadows are declining, prompting the need for restoration efforts. The RENOVATE project, is implementing an integrated methodology for the restoration of Mediterranean marine ecosystems harmed by human activity in elected areas located on the northern Latium coastal area (Italy). Our study focuses on creating detailed habitat maps of Posidonia oceanica meadow at fine scale (1:10.000) to aid restoration efforts. We performed geospatial and geomorphometric analyses on the available datasets, namely multibeam bathymetry and side scan sonar backscatter data. Additionally, we developed a semiautomated approach using Object-Based Image Analysis (OBIA) techniques to detect suitable sites for restoration. The OBIA rulesets, were developed using the eCognition® 10.2 software integrating the original dataset with terrain variables derived from geomorphometric analyses, to classify seafloor units (i.e.: Posidonia oceanica meadow, dead matte of Posidonia oceanica; sediment). Our adaptable methodology (especially the associated ruleset implemented in eCognition) gave prominence to the inclusion of geomorphic processes for restoration site selection, considering factors such as seagrass patchiness and morphology. This research offers an innovative perspective in the implementation of restoration actions for Posidonia oceanica meadows, with likely implications for conservation efforts in wider ecosystems.

The ISOBatA project, funded by the Italian National Antarctic Research Program (PNRA), aims to optimize underway bathymetric data collection in the Antarctic region. This initiative supports the Seabed2030 and the International Bathymetric Chart of the Southern Ocean (IBCSO) projects by allocating dedicated ship time of the R/V Laura Bassi to navigate (1) along designated corridors in uncharted regions of the Southern Ocean, including the Emerald Fracture Zone and the Macquarie Triple Junction, and (2) among yearly monitored locations of the Ross Sea. ISOBatA emphasizes the reuse of existing datasets using the IBCSO coverage map and metadata from prior PNRA expeditions. It also aims to establish best practices and workflows for high-quality bathymetric data acquisition, processing, analysis, and archiving. Bathymetric data collected over the last three PNRA expeditions were integrated with other datasets (e.g., magnetometric, sub-bottom profiling, and oceanographic data) to create maps and validate the approach. Significant discrepancies (up to 1200 meters) were found along the Emerald Fracture Zone in an area where the IBCSO contains only predicted satellite bathymetry, highlighting gaps in our understanding of geodynamic processes. In the Ross Sea, various submarine landforms were detected, revealing the extent of processes shaping the recent evolution of the Antarctic margin (from bottom currents to ice retreat during the last deglaciation). The ISOBatA experience, dataset and findings underscore the importance of collaboration among institutions and research groups to share data and resources and how the application of FAIR principles and practices to underway data collection is critical to expand seafloor coverage, especially in remote areas like the Antarctic region.

Cold seeps play a distinctive geo-ecological role in the deep-sea environment, influencing the dynamics of submarine sedimentary settings and shaping the landscape evolution. In this study, we introduce a comprehensive methodology that utilizes ROV-based multibeam mapping and underwater photogrammetry to enhance our comprehension of the physical interactions among geomorphic features within the Hakon Mosby Mud Volcano (HMMV) and the associated habitat distribution. Our approach integrates data acquired by a work-class ROV at multiple resolutions and from various sources. Microbathymetry data obtained by the ROV revealed different fine-scale submarine landforms in the central region of HMMV, identifying three distinct geomorphic units, with the central hummocky region being the most complex. Further analysis of ROV images, utilizing a defined Structure-from-Motion (SfM) workflow, generated millimetric resolution 2D and 3D models for in-depth exploration of this region. Applying Object-Based Image Analysis (OBIA) to orthomosaics enabled fine classification of main benthic communities, covering an area of 940 m2, including the active seepage zone of the ummhocky rim. Four major substrate types were identified: uncovered mud, high-density bacterial mats, low-density bacterial mats, and sediments with tubeworms. Investigating their relationship with terrain morphology and seepage activity at various spatial scales contributes to a comprehensive understanding of the ecological dynamics of cold seep ecosystems in mud volcanoes. The proposed workflow and innovative processing techniques presented in this study can serve as a model for future research on cold-seep systems. These investigations seek to resolve the interrelation of geomorphic, biogeochemical, and ecological processes in extreme environments marked by spatial patterns in associated habitats and sedimentary settings. This work comprises data collected during the CAGE21-1 cruise and within the framework of the IN

Mangrove forests are one of the most important biological, ecological and economic ecosystems in the world. In the Maldives, they play a crucial role in maintaining coastal biodiversity, providing ecosystem services, such as coastal protection, and supporting livelihoods by providing income and food. Overall, 23 Maldivian islands have at least 1 protected mangrove area. However, knowledge of the mangroves of the Maldives is scarce, scattered and sometimes conflicting. There is a lack of information on a national scale regarding their distribution, diversity, ecological importance and associated biodiversity. The aim of this review is to analyse scientific publications, reports, and online documents on mangroves for the entire Maldivian archipelago to provide the first comprehensive summary of the current state of knowledge of mangroves from a national perspective. This includes the geographical location of mangrove forests, the identity and distribution of mangrove species, ecosystem services, ecological importance and diversity of mangrove-associated flora and fauna. We analysed available information from both the grey literature and scientific publications and found that 14 mangrove species have been documented on 108 islands (9% of all Maldivian islands). Mangroves are mainly concentrated in northern atolls and are associated with diverse flora and fauna. Furthermore, we identified inconsistencies and gaps in the literature and proposed future directions for research. This is crucial for informed decision-making, developing effective conservation strategies and long-term sustainability of mangrove ecosystems.

The research question that the paper investigates is whether the usage of state of the art algorithms for point clouds registration solves the problem of multi-scale vision-based point clouds registration in mixed aerial and underwater environments. This paper reports very preliminary results on the data we have been able to procure, in the context of a coral reef restoration project nearby Magoodhoo Island (Maldives). The results obtained by exploiting state of the art algorithms are promising, considering that those data presents hard samples, in particular for their multi-scale nature (noise in captured 3D points increases with depth). However, further investigation on larger data-sets is needed to confirm the overall applicability of the current algorithms to this problem.

Coral reefs are suffering from both natural and anthropogenic stressors which are posing threats to the survival of countries that completely rely on them for their ecosystem services, such as the Republic of Maldives. In the last years, Maldivian reefs have undergone severe mass bleaching such as the 2016 event which impacted 73% of the corals. This couples with threats posed by corallivore outbreaks, coral diseases, human activities, and pollution. In this context, billions of coral colonies, potentially including the most enigmatic, resistant, and ancient ones—colonies over 5m, likely centennial—such as the giant corals, are at risk. These individuals hold unique information from biological, genetic, and paleoclimatic perspectives, having withstood environmental perturbations. They might hold the key to coral reef resilience. We present preliminary findings of giant coral colonies in the Maldives, located with the assistance of citizen scientists. The data provided was collected based on two levels of complexity, dependent on participants' level of expertise. Colonies have been identified across multiple atolls, with a seemingly higher abundance in the southern part of the archipelago. As expected, Porites sp. is the most common genus identified, with colonies exhibiting various growth forms, often found on slopes of channels and reaching lengths of over 10 m. The objective of this work is to raise awareness about the importance and fragility of these organisms, moreover to provide the Maldivian government with a map of potentially sensitive areas worthy of protection. Additionally, the data serve as the foundation for future studies by experts in different fields.

This study investigates the temporal variations in methane concentration and flare activity in the Hola trough (offshore Norway) during May 2018 and June 2022. Between these time periods, methane seep activity exhibits 3.5 times increase, as evidenced by hydroacoustic measurements. As the seep area in the Hola trough is constantly within the hydrate stability zone, the observed increase cannot be attributed to migration of its shallow boundary due to temperature increase. However, a combination of low tide conditions resulting in a lower sediment pore pressure and a bottom water temperature increase resulting in a lower methane solubility is likely to explain the increase in the number of seeps observed in June 2022. The hypothesis of tide influence is supported by data collected from a piezometer deployed and recovered during the cruise showing that the tidal effect was observed 3 m below the seafloor. Despite the numerous methane seeps detected, methane concentration and gas flow rates near the seafloor were low (<19 nM and <70 mL min−1, respectively) compared to other areas with methane seep activity. This is likely due to strong currents rapidly dispersing methane in the water column. Sub-seafloor investigations identified pathways for gas migration in methane seep areas, influenced by topography. This study provides valuable insights into the temporal dynamics of methane concentrations, flare activity, and gas distribution in the Hola trough, contributing to our understanding of offshore methane dynamics in the region.

Cold seeps are hotspots of biodiversity and can deeply impact the local sediment geochemistry in marine environments (e.g., promoting the formation of authigenic carbonate crusts) throughout all the oceans. Natural gas seepage can lead to changes in sediment properties and nutrient cycling supporting unique benthic fauna living in or near the substrate, eventually promoting the establishment of chemosynthetic biological communities. In this study, a relatively shallow water area offshore northern Svalbard (located at roughly 150m of water depth), where evidence of gas seepage has been observed, is investigated using optical, high-resolution seafloor imagery, and OBIA (Object-Based Image Analysis) techniques. Visual data consists of two photomosaics assembled from frames extracted from videos acquired by means of a work-class Remotely Operated Vehicle (i.e. the ROV ÆGIR 6000), and processed by applying underwater Structure from Motion (SfM) photogrammetry technique. The study aims to detect, classify, and count each single specimen representing benthic epifaunal communities at the seafloor and describe changes in seafloor substrates (i.e. sediment grain size and morphometric attributes) across all the photo-referenced datasets. ArcMap software and direct ROV-based video analysis were used to annotate all visible epibenthic fauna (more than 20,000 individuals), identified to the lowest possible taxonomic level based on discernible external morphological characteristics. In a further step, OBIA techniques (using Trimble eCognition® software) were applied on seafloor geomorphological characteristics, to provide quantitative and repeatable classification of the substrate into four distinct classes. Finally, annotated benthic epifauna and seafloor substrate classes’ data were combined to quantify patterns of community diversity, abundance, and structure in relation to seafloor morphometric parameters. Cluster analysis revealed substrate class similarities, as well as colo

Cold-seeps have a unique geo-ecological significance in the deep-sea environment. They impact the variability of present-day submarine sedimentary environments, affecting the evolution of the landscape over time and creating a variety of submarine landforms, one of which is Mud Volcanoes (MVs). MVs form due to mud, fluids, and gas extrusion, mainly methane, from deeper sedimentary layers. These natural gas seepage systems could significantly affect climate change and the global carbon cycle. We present a comprehensive method that combines ROV-based multibeam mapping and underwater photogrammetry to enhance the understanding of the physical relationships between geomorphic units characterizing the Hakon Mosby Mud Volcano (HMMV) and the distribution of associated habitats. HMMV is indeed characterized by high thermal and geochemical gradients from its centre to the margins, resulting in a clear zonation of chemosynthetic communities. Our approach integrates multi-resolutions and multi-sources data acquired using a work-class ROV. The ROV-based microbathymetry data helped to identify the different types of fine-scale submarine landforms in the central part of HMMV. This revealed three distinct geomorphic units, with the central hummocky region being the most complex. ROV images were analyzed using a defined structure from motion workflow to study this area further, producing millimetric resolution 2D and 3D models. Object-Based Image Analysis (OBIA), applied on orthomosaics, allowed us to obtain a fine classification of main benthic communities covering a total area of 940m2, including the active seepage area of the hummocky rim. Four major substrate types were identified in these regions: uncovered mud, bacterial mats high-density, bacterial mats low- density, sediments and tubeworms. Their relationship with terrain morphology and seepage activity were investigated at different spatial scales, contributing to a deeper understanding the ecological functioning of cold s

Marine restoration projects are becoming increasingly important worldwide to mitigate human-driven impacts on marine ecosystems. Nonetheless, their success rate is highly fluctuating and depends upon a number of variables, such as bio-ecological features of the involved species and the geospatial and geomorphological drivers proper to the habitat concerned. Geospatial and geomorphological variables are undoubtedly key factors in controlling benthic species’ distribution; therefore, an accurate analysis of the latter is of paramount importance to detect the most suitable sites for the restoration efforts. The National RENOVATE project (ecosystemic appRoach to the EvaluatioN and testing of cOmpensation and mitigation actions in the marine enVironment: the cAse of the civiTavEcchia harbuor), coordinated by CMCC (Mediterranean Centre for the study of Climate Changes) and funded by “AdSP (Autorità di Sistema Portuale) of the north-central Tyrrhenian Sea”, is performing an integrated methodology for the compensation of Mediterranean marine ecosystems, damaged by anthropogenic impacts, in selected areas located offshore Civitavecchia harbor, in the central Mediterranean sea. In the context of this project, our work focused on providing high-resolution habitat mapping of a Posidonia oceanica meadow, along with the detection of suitable sites for implementing restoration actions. Geospatial and geomorphometric analyses were applied to the available dataset (i.e. multibeam bathymetry and acoustic backscatter) in addition to design a semi-automatic approach, by using Object-Based Image Analysis (OBIA) techniques, to classify the detected morph-acoustic facies. OBIA techniques consist of two sequential steps: (1) image segmentation into different meaningful image-objects, according to the contextual and spectral characteristics of the pixels composing them; (2) semi-automatic classification on the base of spectral, spatial and contextual characteristics of the image-objects. W

Mangroves are, on a biological and ecological point of view, one of the most important ecosystems in the world, supporting various terrestrial, estuarine, and marine species. They provide them crucial habitat and food, but also provide several ecosystem services, including fisheries enhancement, coastal protection, carbon storage and sequestration. However, in the Maldives, even though their role is even more important, knowledge about their distribution and biodiversity is scarce and their importance is still underestimated. The aim of our project is to conduct the first-ever survey of all mangroves in the Maldives to enhance and increase the understanding of its unique ecosystems in order to take more action to preserve them from human impact and help research teams plan mangrove-related activities in the archipelago. As a first step, we reviewed all the information about mangroves in the Maldives and found 11 true and 4 controversial mangrove species, unevenly distributed from north to south on 109 islands (9% of all islands) with various fauna and flora species associated. The next step was a preliminary exploration of the Maldives. We visited several islands, particularly those in the Gnaviyani and Addu Atolls, finding 2 islands with previously unreported mangroves. In addition, we noted the presence of the four macro-types of mangroves, i.e. fringing, lacustrine-based, banked and swamp-based, with different sub-types and instances of different types even within a single island. In relation to biodiversity, seven mangrove species and several crab and fish species were visually identified with distribution influenced according to the mangrove type. Future prospects will be the nationwide assessment of the mangrove species’ composition and distribution and related fauna and flora with the help of molecular analyses, aerial mapping of areas, and the assessment of the temperature, pH, and salinity of these environments, with the fund of National Biodiversity Future

We present this paper as a broad group of Early Career Researchers (ECRs) active in various disciplines of the Geosciences in the Italian Academia (from palaeontology to underwater geomorphology and climate sciences). We offer some shared points of view on the Italian Academia and specifically on the Geosciences. We highlight the current precarious conditions of non-permanent workers within the Italian Academic system, so as to highlight the situation of Early Career Researchers (ECRs) in the Geosciences, and their general lack of perspective towards a permanent form of employment. Ultimately, this precariousness is one of the main obstacles impacting upon the quality of research. We tackle this aspect by analysing both the persisting gender gap and some perspectives on the future of the precarious figures currently working inside the Italian Academic system. We believe that the modern academic structure is generally unwelcoming to ECRs, to the detriment of high-quality research. Possible solutions, such as changing the current recruitment system, should include a better stabilisation mechanism for ECRs, which would also be essential to gaining a safe work-life balance.

Habitat fragmentation affects biodiversity, but with unclear effects on pollinators and their interactions with plants in anthropized landscapes. Islands could serve as open air laboratories, suitable to disentangle how land-use alteration impacts pollination ecology. In Maldive islands we investigated how pollinator richness, plant-pollinator interactions and pollination efficiency are influenced by the green area fragmentation (i.e., gardens and semi-natural patches). Moreover, we considered the mediating role of pollinator body size and the plant trait of being invasive in shaping interactions. To do this, we surveyed pollinator insects from 11 islands representing a gradient of green area fragmentation. A DNA metabarcoding approach was adopted to identify the pollen transported by pollinators and characterize the plant-pollinator interactions. We found that intermediate levels of green area fragmentation characterized pollinator communities and increased their species richness, while decreasing interaction network complexity. Invasive plants were more frequently found on pollinator bodies than native or exotic noninvasive ones, indicating a concerningly higher potential for pollen dispersal and reproduction of the former ones. Intriguingly, pollinator body size mediated the effect of landscape alteration on interactions, as only the largest bees expanded the foraging diet in terms of plant richness in the transported pollen at increasing fragmentation. In parallel, the pollination efficiency increased with pollinator species richness in two sentinel plants. This study shows that moderate landscape fragmentation of green areas shapes many aspects of the pollination ecosystem service, where despite interactions being less complex and mediated by pollinator body size, pollinator insect biodiversity and potential plant reproduction are supported.

Coralligenous (C) habitat consists of calcareous formations of biogenic origin characteristic of subtidal systems in the Mediterranean Sea. It develops only specific environmental conditions, and its growth is controlled by the delicate balance between bioconstruction and bioerosion processes. C outcrops typify specific areas of the Mediterranean continental shelves. Offshore Marzamemi village (southeastern Sicily, Ionian Sea) peculiar columnar-shaped C outcrops were documented in 2001. Nevertheless, an in depth study of their extension and distribution in the area is still missing. Indeed, this is one of the main goals of the project CRESCIBLUREEF - Grown in the blue: new technologies for knowledge and conservation of Mediterranean reefs . A new 17 km2 high-resolution morpho-bathymetric map was produced using a R2-Sonic2022 MBES system, ground-truthed by ROV surveys. The combination of bathymetric and backscattering data, together with the ROV videos, allowed us to identify five main habitats. From a geomorphological point of view, it was possible to divide the area into four main marine terraces. These terraced landforms are probably the result of eustatic sea-level variations coupled with tectonic processes. Of relevant importance is the correlation between C reefs distribution with this geomorphological layout. Indeed, C build-ups result to be more widely spread over the shallowest and deeper terraces at selected depth ranges, from 36 to 42 m and from 82 to 102 m of water depth, respectively. This study represents a starting point for the understanding of such a complex habitat, which is among the most important in the Mediterranean Sea and under protection by several legal instruments. Further investigations are needed to better understand the C settling in respect to this inherited continental shelf landscape. This is valid under both the biological and geomorhological point of view, as C habitat is a hotspot of biodiversity, and the outcrops affect present-da

Coralligenous Bioconstructions (CB) include calcareous build-ups of biogenic origin that typify selected regions of the Mediterranean continental shelves, where they formed since the Holocene transgression. They can be from few to tens of meters large, displaying variable lateral continuity and thickness. Offshore Marzamemi (south-eastern Sicily, Ionian Sea) the occurrence of peculiar columnar-shaped CB have been documented in 2002, but their actual extension and distribution across the shelf was not known until recent time. The project “CresciBluReef: New technologies for knowledge and conservation of Mediterranean reefs” produced a new17 km2 high-resolution bathymetric map using a R2Sonic2022 MBES, ground-truthed by ROV observations, that generated a good knowledge of the extension of CB in the region. The bioconstructions are preferentially distributed along selected depth ranges (from 30 to 40 m, and from 85 and 95 m of w.d.), with a good lateral continuity. The coupling of documented uplift rate (ca. 0.2 mm/yr since the Tyrrhenian time) and evidences reported in literature for Holocene relative sea-level curves, shows a good correlation between the distribution of CB and local and short stasis associated to the rapid Flandrian transgression. However, as revealed by the geomorphological map obtained by our study, a more in-depth investigation is needed to understand (1) the role of the inherited continental shelf landscape, shaped by previous low-stand periods, in creating favourable substrate for the settlement and growth of CB during the Holocene, and (2) the extent to which CB can in turn affect the evolution of present-day continental shelf landforms and landscapes.

Immersive virtual reality can potentially open up interesting geological sites to students, academics and others who may not have had the opportunity to visit such sites previously. We study how users perceive the usefulness of an immersive virtual reality approach applied to Earth Sciences teaching and communication. During nine immersive virtual reality-based events held in 2018 and 2019 in various locations (Vienna in Austria, Milan and Catania in Italy, Santorini in Greece), a large number of visitors had the opportunity to navigate, in immersive mode, across geological landscapes reconstructed by cutting-edge, unmanned aerial system-based photogrammetry techniques. The reconstructed virtual geological environments are specifically chosen virtual geosites, from Santorini (Greece), the North Volcanic Zone (Iceland), and Mt. Etna (Italy). Following the user experiences, we collected 459 questionnaires, with a large spread in participant age and cultural background. We find that the majority of respondents would be willing to repeat the immersive virtual reality experience, and importantly, most of the students and Earth Science academics who took part in the navigation confirmed the usefulness of this approach for geo-education purposes.

Along the Mediterranean Sea shelf, algal reefs made of crustose coralline algae and Peyssonneliales are known as Coralligenous. It ranks among the most important ecosystems in the Mediterranean Sea because of its extent, complexity, and heterogeneity, supporting very high levels of biodiversity. Descriptive approaches for monitoring purposes are often aimed at assessing the surficial ephemeral canopy, which is sustained and controlled by the occurrence of the long-lasting rigid structure at the base. This practice led to the non-univocal definition of Coralligenous, sometimes indicated as “animal Coralligenous” because of the surficial dominance of these components. The quantitative assessment of the builders that actively build up the persistent structure through geological time is therefore a fundamental topic. We collected two discrete coralligenous samples in front of Marzamemi village (Sicily, Ionian Sea), the first from an area of a dense coralligenous cover (- 37 m) and the second one from an area with sparse build-ups (- 36 m). By using image analysis and computerized axial tomography, we distinguished and quantified the different components both on the surface and inside the framework. In both cases, our results confirm the primary role of crustose coralline algae as major builders of the Mediterranean Coralligenous, this aspect matching with the evidence from the Quaternary fossil record. We suggest that the role of encrusting calcareous red algae in the Coralligenous should be considered in conservation and management policies.

In this body of work, we showcase a historic virtual geotrail on the eastern flank of the iconic Mt. Etna volcano (Italy), along a series of outstanding geological sites and features subsequent to an important eruption that took place in 1928. A geohistoric account of such a major eruption, is of great interest, since it is the only event since 1669 to have caused the destruction of a town (Mascali) in the Etna region. Volcanologists, educators, the lay public, tourists and volcano explorers can now access a series of “virtual geostops” belonging to this virtual geotrail, such that “visitors” can virtually fly above these sites by scanning a QR code on the printed or electronic version of the present manuscript, as well as on the poster provided as additional material for this manuscript. The virtual geostops that comprise the virtual geotrail were developed using the structure-from-motion (SfM) photogrammetry technique from images captured by using unmanned aerial vehicles (UAVs). The main result of our work is the virtual geotrail, subdivided in two parts and composed of eight geostops, each showing outstanding examples of geological features resulting from volcanic phenomena that took place also during 1979. Our approach is designed to support classical field trips, and it can undoubtedly become complementary to traditional field teaching in earth sciences, both now and in the future.

Crustose coralline algae (CCA) form Coralligenous build-ups, which are ranked among the most important ecosystems in the Mediterranean shelf. Their skeletal framework hosts a variety of epi- and infaunal communities, which compete for space, contributing to the reef growth, or weaken the structure throughout bio-erosive activities. Investigating the relationship between the algal framework and these hosted communities is of extreme importance for ecological and palaeoecological purposes and monitoring goals. In this frame, the Italian project “CRESCIBLUREEF - Grown in the blue: new technologies for the knowledge and conservation of the Mediterranean reefs”, is aimed at investigating coralligenous reefs present in the area off the Marzamemi village (South-East Sicily). Two build-ups have been collected: the first one at 37 m depth, from an area rich in coralligenous cover, and the second one at 36 m depth, from a submarine channel with sparsely distributed build-ups. We present here two new investigative techniques, so far seldom applied for the characterization of the Coralligenous. The first approach involved the quantification of the surficial cover, with the use of an image analysis software, both before and after the removal of their ephemeral canopy of unmineralized organisms.These models were then analysed using Object-Based Image Analysis (OBIA) algorithms that allowed the quantification of the surficial cover. Moreover, the analysis allowed the identification and categorisation of the organisms and materials on the external part of the build-ups, confirming the primary role of CCA as the major component of the samples. Afterwards, a Computed-Tomography (CT) scan was used - for the first time with Coralligenous - to reconstruct the inner structure of the build-ups and, together with radiocarbon dating, to infer the build-ups age and growth rate. CT analysis divided the framework into four main categories based on their density (Low, Medium, High and Ultra Hig

Coralligenous (C) is a type of Open Frame Reef, characterized by a variable association of calcareous red algae and macroinvertebrates. It is distributed across the Mediterranean shelf below the deepest seagrass meadows and down to the mesophotic zone, with different facies. The Italian project FISR “CRESCIBLUREEF” provided an extraordinary opportunity to explore the development of the Mediterranean C, from inception to present-day morphology and distribution off the SE coasts of Sicily. The spatial extension of C hybrid banks and discrete reliefs over the studied Sicilian shelf controls the hydrodynamics at the seafloor, the habitat biodiversity, and the related carbonate production at the shelf scale. The analyzed C samples, collected at about 36 m depth, had a columnar shape, were Holocene in age, and their development significantly modified the seafloor geomorphology. Our observations confirmed that most of the framework was built by calcareous red algae with an important contribution by bryozoans, with serpulids, molluscs, and rare corals as accompanying components of the sessile macroscopic fauna. The framework was highly porous, with a primary porosity derived from the growth, shape and structure of the skeletal components of both builders and dwellers, and an important secondary porosity derived from bioerosion and other early taphonomic processes involving both skeletonised and soft-bodied organisms, like sponges. During the entire process of framework growth and development, sponges played an important role as mineralization mediators of the autochthonous micrite fraction, which contributes significantly to the framework consolidation. Detrital micrite, rich in fine skeletal remains, is trapped in the primary and secondary cavities and represents an archive for the study of the organisms which are not directly involved in the framework building.

Recent advances in underwater and airborne robotic systems and ocean technologies have opened new perspectives in marine geology and its applications in the context of coastal and marine economic activities, whose sustainable development is increasingly acknowledged as a pillar for the new blue economy. BridgET (Bridging the gap between the land and the sea in a virtual Environment for innovative Teaching and community involvement in the science of climate change-induced marine and coastal geohazard) is an EU ERASMUS+ project designed to develop innovative and inclusive teaching methods to address a growing demand for strategic skills and scientific expertise in the field of 3D geological mapping of coastal environments. Seamless integration of the wide variety of multisource and multiscale onshore, nearshore and offshore geospatial data is indeed one of the main areas for improvement in the implementation of efficient management practices in coastal regions, where climate change, rising sea level, and geohazards are considerable environmental issues. BridgET involves a partnership consisting of six European universities with outstanding expertise in the study of geological hazards, and climate impacts in marine and coastal areas (i.e., University of Milano-Bicocca, Italy, Arctic University of Tromsø/CAGE - Norway, National and Kapodistrian University of Athens - Greece, Kiel University, Germany, University of Liege – Belgium, and the University of Malta), two Italian research institutes (INGV and INAF) and a German company (Orthodrone GmvH) specialized in UAS-based LiDAR and photogrammetry data acquisition services and analyses. Project implementation relies on delivering learning and teaching activities through dedicated summer schools for MSc students by efficiently combining the partner’s expertise. Schools focus on giving students a hands-on experience with the variety of methods and procedures adopted in geospatial data acquisition and processing, including th

Multibeam echosounders (MBES) mounted on remotely operated vehicles (ROVs) can acquire sub-metric resolution bathymetry in deep water environments. However, a general lack of complexity measurements of peculiar seafloor morphologies (sub-metric and centimetric resolution) represents a knowledge gap that can be mitigated through an innovative image analysis technique: Structure from Motion (SfM). 3D photogrammetry is becoming more relevant in land and marine imaging research, opening new opportunities for the extraction of fine-scale terrain variables and high-resolution habitat mapping that may contribute to understanding the functioning of extreme deep-sea environments, such as cold seeps habitats. Cold seeps are seafloor areas where reduced compounds from subsurface hydrocarbon reserves either enrich sediment fluids or emanate freely as gas from the seabed. Numerous underwater landscapes and various chemosynthetic communities are associated with these biodiversity hotspots, which were uncovered during the last decades of seafloor exploration. In this work, we integrated ROV-based MBES bathymetric datasets with multi-dimensional, high-resolution seafloor models obtained from ROV photogrammetry to improve (i) the understanding of the geospatial context of Cold Seeps distribution and (ii) their spatial extent from a multiscale perspective. An arctic cold seep on Svyatogor Ridge, offshore Svalbard, was explored using Ægir6000, a work-class ROV equipped with a Kongsberg EM 2040 MBES and 8 HD and composite video camera inputs, which provide a fully operational vision with a zoom and focus capability able to film the ocean floor at different angles. The lighting capacity includes ten dimmable lights and has a maximum total load of 2300 W. ROV-based multibeam micro-bathymetry was performed on a selected area at 45 m of altitude from the seafloor at a speed of 0,5 knot to map the near bottom environments in detail. Sub-portions of the same areas were then mapped using a ph

I libri di testo hanno un ruolo fondamentale nella trasmissione dei saperi a scuola. In occasione del decennio ONU dedicato alle scienze del mare si è voluto analizzare come i libri di testo per la scuola primaria affrontino questo spazio. La visione del mare che è veicolata da questi strumenti è fortemente terracentrica, il mare è prevalentemente descritto come il limite della terra ferma. Dal punto di vista iconografico si riscontrano delle contraddizioni tra testo e immagini, inoltre il mare è prevalentemente rappresentato sulla falsa riga della sua immagine turistica.

Coralligenous (C) include calcareous build-ups of biogenic origin, formed since the Holocene transgression. Peculiar columnar-shaped C outcrops were documented offshore Marzamemi village (SE Sicily, Ionian Sea), although the actual extension and distribution were not assessed. Project ‘CRESCIBLUREEF’ produced a new, 17 km2 high-resolution bathymetric map, leading to good knowledge about their extent in this area. C bioconstructions are largely distributed along two depth ranges 36–42 m and 86–102 m water depth. By coupling the documented uplift rate in this region and the Holocene sea-level curve, we were able to interpret the distribution of C outcrops over terraces. However, additional investigation is required to understand: (1) the role of the inherited continental shelf landscape, in creating a favorable substrate for the settlement and growth of C habitats during the Holocene, and (2) the extent to which C bioconstructions can impact the evolution of present-day continental shelf landforms and landscapes.

Cold-seep systems have a unique geo-ecological significance in the deep-sea environment. They impact the variability of present-day submarine sedimentary environments, affecting the evolution of the landscape over time and creating a variety of submarine landforms, one of which is Mud Volcanoes (MVs). MVs are submarine landforms form due extrusion of mud, fluids, and gas, mainly methane, from deeper sedimentary layers. These natural gas seepage systems could significantly affect climate change and the global carbon cycle. We present a comprehensive method that combines ROV-based multibeam mapping and underwater photogrammetry to enhance the understanding of the geomorphic units characterizing the Håkon Mosby Mud Volcano (HMMV) and the distribution of associated habitats. HMMV is indeed characterized by high thermal and geochemical gradients from its center to the margins resulting in a clear zonation of chemosynthetic communities. Our approach integrates multi-resolutions and multi-sources data acquired using a work-class ROV. The ROV-based microbathymetry data helped to identify the different types of fine-scale submarine landforms in the central part of HMMV. This revealed three distinct geomorphic units, with the central hummocky region being the most complex. To further study this area, ROV images were analyzed using a defined Structure from Motion workflow producing millimetric resolution 2D and 3D models. Object-Based Image Analysis (OBIA), applied on orthomosaics, allowed us to obtain a fine classification of main benthic communities covering a total area of 940m2, including the active seepage area of the hummocky rim. Four major substrate types were distinctly imaged in these regions: uncovered mud, bacterial mats high-density, bacterial mats low-density, sediments and tubeworms. Their relationship with terrain morphology and seepage activity was investigated at different scale, contributing to a deeper understanding the ecological functioning of cold seep

In the present work we applied the use of the UAV-based Structure from Motion technique (SfM) to geological and geohazard studies, with emphasis placed on active tectonics and volcano-tectonics cases. Our aim is to obtain high-resolution orthomosaics and Digital Surface Models (DSMs) in two study areas: the Theistareykir Fissure Swarm within the Northern Volcanic Zone (NVZ) of Iceland and the active Khoko landslide, Enguri reservoir, in the Greater Caucasus, Georgia. The first is affected by seismic and volcanic hazard, the second by landslide and hydrogeological hazard. Regarding the NVZ, by analysing the resulting Orthomosaics and DSMs we collected a total of 453 quantitative measurements of the amount of opening and opening direction of Holocene extension fractures and 36 measurements of the height of fault scarps. These data allowed us to assess an overall spreading direction of N106.4° during Holocene times within the studied rift zone, which has been compared with geodetic motion vectors, and a stretching ratio of 1.013–1.017 for 8–10 ka old lava units. We conclude that deformation in the area is related to both dyke intrusions and extensional tectonics. In the Greater Caucasus, we applied the method to identify the main geomorphological features related to the Khoko landslide and to measure the scarp height of the principal slip surfaces, in order to improve geomorphological knowledge of the landslide, and contribute to the assessment of the hydrogeological hazard of the area. At a general level, our results suggest that the use of UAV-based SfM is a convenient and efficient way to collect plenty of data aimed at better assessing geohazards in areas prone to catastrophic natural phenomena like earthquakes, volcanic eruptions and landslides.

We document and show a state-of-the-art methodology that could allow geoheritage sites (geosites) to become accessible to scientific and non-scientific audiences through immersive and non-immersive virtual reality applications. This is achieved through a dedicated WebGIS platform, particularly handy in communicating geoscience during the COVID-19 era. For this application, we selected nine volcanic outcrops in Santorini, Greece. The latter are mainly associated with several geological processes (e.g., dyking, explosive, and effusive eruptions). In particular, they have been associated with the famous Late Bronze Age (LBA) eruption, which made them ideal for geoher-itage popularization objectives since they combine scientific and educational purposes with ge-otourism applications. Initially, we transformed these stunning volcanological outcrops into geo-spatial models—the so called virtual outcrops (VOs) here defined as virtual geosites (VGs)—through UAV-based photogrammetry and 3D modeling. In the next step, we uploaded them on an online platform that is fully accessible for Earth science teaching and communication. The nine VGs are currently accessible on a PC, a smartphone, or a tablet. Each one includes a detailed description and plenty of annotations available for the viewers during 3D exploration. We hope this work will be regarded as a forward model application for Earth sciences' popularization and make geoheritage open to the scientific community and the lay public.

Freshwaters constitute a fundamental and extremely limited resource for atoll islands' population. The interplay of climatic and human-driven processes, which affect both the quantity and the quality of freshwater resources, may exacerbate the problem of water security and availability. This work evaluated the effects of good spectrum of anthropic impacts on groundwater quality in a typical and representative native inhabited island (c.a. 850 people) of Maldives, analyzing and interpreting hydrological and hydrochemical data, collected during a specific field survey on 51 sampling points after a rainy season. The island groundwater is constituted by a thin asymmetric lens, periodically recharged by rain. The lifestyle of people and water exploitation seem to be sustainable, even if groundwater resources are already experiencing moderate contamination and, limited to some areas, heavy pollution. The sources of impacts have been identified in diffuse organic matter contamination due to a poor domestic wastewater treatment, farming (poultry) and gardening activities. To face these impacts, it is essential to build a sewer system paired with a possibility to recycle wastewater reducing water over-exploitation. The collaborative and educational initiatives organization, at different levels, can increase the capacity for planning a sustainable development. Our results provide useful information for sustainable management plans to preserve freshwater resources of the island, which conservation is especially important considering the context of the future lifestyle changes and climatic scenarios for the Maldives. These findings can be extended by analogy to others atoll islands.

Coralligenous (C) bioconstructions include calcareous build-ups of biogenic origin that typify selected regions of the Mediterranean Sea. These peculiar habitats thrive from shallow waters (15-20 m of water depth (w.d.) up to the limit of the mesophotic zone, and they formed since the Holocene transgression. They are from few to tens of meters large, displaying variable lateral continuity and thickness. Peculiar C outcrops are present offshore Marzamemi (southeastern Sicily, Ionian Sea). Their extension and distribution across the shelf were investigated within the project CRESCIBLUREEF - Grown in the blue: new technologies for knowledge and conservation of Mediterranean reefs. We produced a new 17 km2 high-resolution bathymetric map using a R2-Sonic 2022 system, ground-truthed by ROV video inspections. From a geomorphological point of view, the shelf is typified by four distinct marine terraces. Climate change and tectonic uplift are the dominant forcing mechanisms responsible for the formation of long and narrow terraced landforms in a variety of geomorphic settings; and marine terraces are largely used to reconstruct the Quaternary glacial and interglacial climates. The coupling of documented uplift rate in this region (ca. 0.2 mm/yr since the Tyrrhenian time) and the evidence reported in literature for late Quaternary relative sea-level curves shows a good correlation between the distribution of C outcrops and local, short stasis of sea level transgression periods, culminated with the rapid Flandrian transgression. C outcrops are mainly spread over the first and last terraces at two specific depth ranges: from 36 to 42 m of w.d., and from 86 to 102 m of w.d., respectively. Settlement and growth were mainly favored by a low sedimentation regime. Indeed, lowstand stages were likely characterized by erosional forces. This is particularly noticeable in the middle of our study area, where we have a paleo-incision typified by peculiar erosional features we were able t

Coralligenous Bioconstructions (CB) include calcareous build-ups of biogenic origin that typify selected regions of the Mediterranean continental shelves, where they formed since the Holocene transgression. They can be from few to tens of meters large, displaying variable lateral continuity and thickness. Offshore Marzamemi (south-eastern Sicily, Ionian Sea) the occurrence of peculiar columnar-shaped CB have been documented in 2002, but their actual extension and distribution across the shelf was not known until recent time. The project “CresciBluReef: New technologies for knowledge and conservation of Mediterranean reefs” produced a new 17 km2 high-resolution bathymetric map using a R2Sonic2022 MBES, ground-truthed by ROV observations, that generated a good knowledge of the extension of CB in the region. The bioconstructions are preferentially distributed along selected depth ranges (from 30 to 40 m, and from 85 and 95 m of w.d.), with a good lateral continuity. The coupling of documented uplift rate (ca. 0.2 mm/yr since the Tyrrhenian time) and evidences reported in literature for Holocene relative sea-level curves, shows a good correlation between the distribution of CB and local and short stasis associated to the rapid Flandrian transgression. However, as revealed by the geomorphological map obtained by our study, a more in-depth investigation is needed to understand (1) the role of the inherited continental shelf landscape, shaped by previous low-stand periods, in creating favourable substrate for the settlement and growth of CB during the Holocene, and (2) the extent to which CB can in turn affect the evolution of present-day continental shelf landforms and landscapes.

The cushion seastar Culcita schmideliana has gained major attention in the last few years because of its selective predation on juvenile corals, as well as its ability to generate large demographic assemblages, causing delays in coral recovery after large mortality events in the Republic of Maldives. However, a lack of data regarding the factors affecting its distribution and habitat selection still persists in this area. Here, we adopted a novel approach in the study of corallivorous seastar habitat selection that combined ecological and digital photogrammetry data. In this regard, we tested 3 different parameters as factors influencing seastar habitat choice in the South-East region of Faafu Atoll, Republic of Maldives, namely prey abundance, Linear Rugosity Index (LRI), and Average Slope (AS). The analysis of selectivity coefficient (Ei) of seastars for different habitat types showed a preference for reefs characterized by medium AS values (Ei = 0.268), a LRI included between 2 and 2.5 (Ei = 0.180), and a juvenile coral density ranging between 10 and 20 colonies m−2 (Ei = 0.154). A multiple linear regression analysis showed that different AS and LRI values explained the 43.1% (R2 = 0.431, P = 0.007) and the 48.1% (R2 = 0.481, P = 0.024) of variance in seastars abundance, respectively, while juvenile coral densities did not significantly affect this (R2 = 0.132, P = 0.202). These results provide new information on the distribution and behaviour of an important corallivore of Maldivian reefs, such as C. schmideliana.

In the present work, we have obtained a detailed, complete view of surface deformation at a volcano-tectonic structure belonging to the Krafla Fissure Swarm (NE Iceland), through the integration of field mapping and the Aerial Structure from Motion technique (ASfM), as well as through orthomosaics and Digital Surface Models (DSMs). The documented, 2.5-km-long deformation zone is marked by a range of features, such as topographic bulging, parallel extension fractures, and narrow grabens affected by local floor uplift, which we have explained as the effect of the northward, shallow propagation of a dyke from the Krafla magma chamber. Our lithostratigraphic field survey of the area, at a 1: 5000 scale, indicates that major changes in the pattern of surface deformation take place across the contacts between deposits with different rheological properties. The transition from very stiff lavas to softer hyaloclastites produces changes from extensional fracturing to normal faulting, though the width of the deformation zone does not change. We have also documented a number of NE-SW, left-lateral and NNW-SSE, right-lateral strike-slip fault zones that are rotated in clockwise and anticlockwise sense to the main NNE-SSW graben trend, and extend outwards as much as about 17 m. The graben zone terminates to the north by splitting into two strike-slip fault zones. These were likely generated at the front of the dyke tip during its propagation, and were later on bypassed by the advancement of the dyke. As the dyke entered the soft hyaloclastites, propagation was slowed down and the dyke became thicker.

Quantifying the extension rate and the spreading direction in a rift zone is fundamental for several reasons, like the assessment of seismic and volcanic hazard. However, this work requires the collection of a huge amount of precise data along a rift zone, which sometimes can be difficult to obtain, due to hard logistic conditions or to the large width of the study area. In our work we show how the use of UAVs, coupled with Structure-from-Motion (SfM) photogrammetry, allows to overcome these problems and to collect plenty of data even in difficult terrains, where field survey can be affected by the logistics.We applied this technique in a 2.7 km2 - large area located in the NW part of the Krafla Fissure Swarm (NE Iceland), an active volcanic rift in the Northern Volcanic Zone of Iceland composed of extension fractures, normal faults, eruptive fissures and a central volcano. The study area is situated about 7 km north of the central caldera, and it is characterized by the presence of extension fractures and normal faults, affecting two lava flows dated 11-12 ka BP, and a hyaloclastite ridge dated back to the Weichselian High Glacial (29.1-12.1 ka BP).The area has been surveyed through 9 different missions, carried out during summer 2019, which allowed to collect a total of 6068 photos. Thanks to the SfM workflow, we obtained a high quality Orthomosaic (2.59 cm/pixel resolution), a DSM (10.40 cm/pixel resolution), and a 3-D Tiled model. By importing the resulting models in a GIS environment, we were able to redraw the geological map of the area, tracing the limits with very high detail, and thus to recognize and map a total of 1355 fractures, classified as normal faults (86) and extension fractures (1269). Moreover, we took structural measurements along both extension fractures and normal faults: at extension fractures, we measured opening directions, local strike and amount of opening in 568 sites, for a total of 1704 structural data, whereas at normal faults we quan

In the present work, we test the application of boat-camera-based photogrammetry as a tool for Virtual Outcrops (VOs) building on geological mapping and data collection. We used a 20 MPX camera run by an operator who collected pictures almost continuously, keeping the camera parallel to the ground and opposite to the target during a boat survey. Our selected target was the northern part of Santorini's caldera wall, a structure of great geological interest. A total of 887 pictures were collected along a 5.5-km-long section along an almost vertical caldera outcrop. The survey was performed at a constant boat speed of about 4 m/s and a coastal approaching range of 35.8 to 296.5m. Using the Structure from Motion technique we: i) produced a successful and high-resolution 3D model of the studied area, ii) designed high-resolution VOs for two selected caldera sections, iii) investigated the regional geology, iv) collected qualitative and quantitative structural data along the vertical caldera cliff, and v) provided a new VO building approach in extreme logistic conditions.

This study used wastewater-based epidemiology (WBE) to investigate the lifestyle of the inhabitants of Malé, the capital of the Republic of Maldives. Raw wastewater 12-h composite samples were collected from nine pumping stations serving the city area - thus representative of the whole Malé population. Samples were analysed by liquid chromatography coupled to mass spectrometry for estimating the profile of use of a large number of substances including illicit drugs, alcohol, caffeine, tobacco and pharmaceuticals. The illicit drugs most used were cannabis (THC) and heroin (700 and 18 g/day), with lower consumption of cocaine and amphetamines (0.1–1.2 g/day). It is important to note that the consumption of cannabis in Malé was comparable to that measured in other countries, while the consumption of heroin was higher. Among cathinones, mephedrone was detected at the highest levels similar to other countries. Consumption of alcohol, which is not allowed in Maldives, was found (1.3 L/day/1000 inhabitants), but at a low level compared with other countries (6–44 L/day/1000 inhabitants), while the consumption of caffeine and tobacco was generally in line with reports from other countries. Unique information on pharmaceuticals use was also provided, since no official data were available. Human lifestyle was evaluated by applying for the first time the full set of WBE methodologies available in our laboratory. Results provided valuable epidemiological information, which may be useful for national and international agencies to understand population lifestyles better, including illicit drug issues, and for planning and evaluation of drug prevention programs in Malé.

Coral reefs are declining worldwide as a result of the effects of multiple natural and anthropogenic stressors, including regional-scale temperature-induced coral bleaching. Such events have caused significant coral mortality, leading to an evident structural collapse of reefs and shifts in associated benthic communities. In this scenario, reasonable mapping techniques and best practices are critical to improving data collection to describe spatial and temporal patterns of coral reefs after a significant bleaching impact. Our study employed the potential of a consumer-grade drone, coupled with structure from motion and object-based image analysis to investigate for the first time a tool to monitor changes in substrate composition and the associated deterioration in reef environments in a Maldivian shallow-water coral reef. Three key substrate types (hard coral, coral rubble and sand) were detected with high accuracy on high-resolution orthomosaics collected from four sub-areas. Multi-temporal acquisition of UAV data allowed us to compare the classified maps over time (February 2017, November 2018) and obtain evidence of the relevant deterioration in structural complexity of flat reef environments that occurred after the 2016 mass bleaching event. We believe that our proposed methodology offers a cost-effective procedure that is well suited to generate maps for the long-term monitoring of changes in substrate type and reef complexity in shallow water

In the present work, we demonstrate how drone surveys coupled with structure-from-motion (SfM) photogrammetry can help to collect huge amounts of very detailed data even in rough terrains where logistics can affect classical field surveys. The area of study is located in the NW part of the Krafla Fissure Swarm (NE Iceland), a volcanotectonic rift composed of eruptive centres, extension fractures, and normal faults. The surveyed sector is characterized by the presence of a hyaloclastite ridge composed of deposits dated, on a stratigraphic basis, to the Weichselian High Glacial (29.1–12.1 ka BP), and a series of lava flows mostly dating back to 11–12 ka BP. The integration of remotely sensed surveys and field inspections enabled us to recognize that this segment of the Krafla rift is made of grabens arranged en-échelon with a left-stepping geometry. A major graben increases in width in correspondence of the hyaloclastite cone; we interpret this geometry as resulting from the mechanical contrast between the stiffer lava succession and the softer hyaloclastites, which favours the development of concentric faults. We also measured a total extension of 16.6 m and 11.2 m along the fractures affecting the lava units, and a total extension in the hyaloclastites of 29.3 m. This produces an extension rate of 1.4 mm/yr in the Holocene lavas and 1.7 ± 0.7 mm/yr in the Weichselian hyaloclastite deposits. The spreading direction we obtained for this area is N97.7° E, resulting from the av. of 568 opening direction values.