bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantifying active faulting using marine terraces, Kythera Island, Greece
Authors: Tsanakas Konstantinos , Jara-Muñoz Julius , Karymbalis Efthimios , Yildirim Cengiz , Pedoja Kevin , Batzakis Dimitrios-Vasileios , Griva Diamantina
Published: June 2022

Offshore islands may furnish valuable information regarding deformation rates, their controlling mechanisms, and the dynamics of the upper crust in offshore areas along subduction zones, which otherwise would be difficult to quantify by direct observations. Here we study active deformation and faulting at glacial-cycle time scales in the Kythera Island, located in the southwestern part of the Hellenic subduction zone, between Crete and the Peloponnesus. The Kythera Island exposes an outstanding sequence of more than twelve levels of marine terraces that depict the active uplift of the island. These terraces are offset by several NNW-SSE and NNE-SSW-oriented active faults. We use high-resolution topography combined with morphometric analysis to map the marine terraces and to estimate the heave and throw rates of the main faults on the island. We divide the marine terrace sequence into two groups, the higher marine terraces (260 – 480 masl) comprising composite rasa surfaces, and the lower terraces (20 – 220 masl) characterized by staircase morphologies. We focus on the two main faults of the island, defined as F1 and F2, which display right- and left-lateral and dip-slip displacements, offsetting the marine terrace risers and treads. We link the activity of these faults with the occurrence of intermediate-depth and strong magnitude earthquakes such as the Mw 6.6 and 6.7 that occurred in the area of Kythera in 1903 and 2006, respectively.  Further dating of marine terrace surfaces and structural analysis will be carried out in the next months in order to correlate the marine terraces with Marine Isotope Stages and to estimate heave and throw rates of the faults. Our work emphasizes the importance of carrying observations in islands to elucidate the deformation rates in offshore areas of subduction zones.
Microhabitats of a threatened freshwater mussel in gravel-bed rivers (Belgium).
Authors: Vaessen Quintia , Houbrechts Geoffrey
Published: June 2022

Physical microhabitat descriptors are important to predict species habitat and therefore, are critical to river management as a mean to identify and manage habitats of aquatic fauna. Flow velocity, water depth and substrate constitute the fundamental microhabitat of benthic macroinvertebrates. The thick shelled river mussel (Unio crassus) is an endangered European freshwater mussel. The species and its habitat are protected in Europe by Council Directive 92/43/EEC (Annexes II and IV) on the conservation of natural habitats and of wild fauna and flora. Therefore, Member States must establish conservation strategies for this species. In this context, microhabitats of the thick shelled river mussel are mapped in several Belgian rivers, along with the use of the microhabitat by the species. For each microhabitat descriptor i.e., bathymetry, flow velocity, and substrate grain size, a habitat suitability index is computed. Habitat suitability index is defined as the ratio of the species’ use of a microhabitat to its availability. Optimal microhabitat is defined as the microhabitat having to highest frequency of use by mussels. Each shell is measured to detect size-related differences in microhabitat use. The hydromorphological preferences of the threatened mussel are thus identified which will allow the development of habitat suitability criteria for the adult life stage of the species.
Lacustrine terraces in Uidzegiin Lake and Bolgoin Govi in the eastern Mongolia
Authors: Tanaka Yukiya , Kang Su-Min , Ochir Altansukh
Published: June 2022

Eastern Mongolia is located at the summer monsoon limit. This means that the climate of the eastern Mongolia is strongly affected by strength of summer monsoon due to climate change. The present study aims to elucidate palaeohydrological environment change of the eastern Mongolia through analysis of lacustrine terrace deposits (Uidzegiin lake and Bolgoin Govi). Uidzegiin lake is located at the Ongon Soum, the southeastern Mongolia. This lake is desiccated saline lake with at least four lacustrine terraces (1040m, 1030m, 1020m and 1010m a.s.l.). These lacustrine terraces are widely distributed around present Uidzegiin lake and Bolgoin Govi (Palaeolake). This means that the lake level was high and the area of lake was expanded during Mid Holocene.
Neoglacial oscillations in the northern Fildes Peninsula, King George Island, Antarctica
Authors: Oliva Marc , Palacios David , Fernández-Fernández José M. , Fernandes Marcelo , Schimmelpfennig Irene , Vieira Gonçalo , Antoniades Dermot , Pérez-Alberti Augusto , Garcia-Oteyza Julia
Published: June 2022

The spatial and temporal patterns of Holocene glacial oscillations in most currently ice-free areas of Antarctica remains unknown. This work focuses on the recent deglaciation in the northern sector of the Fildes Peninsula, King George Island, northern Antarctic Peninsula. The ice cap covering ca. 90% of the island has receded since the last glacial maximum and exposed ca. 29 km2 of ice-free land. We reconstruct its glacial history based on a dataset of 12 36Cl exposure ages obtained through Cosmic-Ray Exposure (CRE) dating of moraine boulders, polished surfaces and erratic boulders surrounding the peninsula’s northern plateau. Results reveal that the deglaciation of the northern Fildes Peninsula took place during the Holocene Thermal Maximum at 7-6 ka, when warm conditions promoted a massive glacial retreat. The present arrangement of ice-free areas was in place by 6 ka. Small cirque moraines suggest the subsequent occurrence of favourable climate conditions for glacial expansion fed by intense snow deflation at 4.6 and 1 ka at the foot of the northern plateau. The deglaciation pattern of the Fildes Peninsula resulted from the combined shrinkage of different ice masses, rather than of the long-term retreat of the King George Ice Cap. No evidence of glacier expansion during more recent cold periods (i.e. the Little Ice Age) was found. These results fit well with regional deglacial histories inferred from lacustrine sediments and raised beaches and complement the existing chronological framework to help better understand the peninsula’s Holocene geoecological dynamics.
Use of historical aerial photographs to study the evolution of saltmarshes in the Tróia sandspit, Sado estuary, Portugal
Authors: Cunha Ana , Inácio Miguel , Freitas Maria da Conceição , Leira Manel
Published: June 2022

Saltmarshes are a valuable wildlife habitat and play a key role in shoreline protection; given their potential in carbon sequestration and storage, these areas might also play a significant role within mitigation strategies to climate change. Natural saltmarshes can adapt to various disturbances through a series of feedbacks. However, land use changes and human occupation can alter the marsh natural dynamics diminishing their resilience.

Aerial photographs have been used to study marsh vegetation and map its evolution since the late 70’s and have proven to be a key source of information. This technique facilitates the study of wetlands on a monthly, yearly, or decadal timescales. Historical photographs can be used to identify past trends and support the implementation of monitoring programs on vast wetland areas.

In the region of the Tróia peninsula in the Sado estuary (SW Portugal), historical aerial photographs are available for the past 70 years. Using these photographs, this work attempts to answer the following questions: (1) How have the saltmarshes of Sado estuary change since the 1940’s? (2) How have marsh geomorphology and anthropogenic pressure contributed to these changes? (3) Is the variation of sea level in the Portuguese coast an important factor in marsh evolution?

From the saltmarshes that were studied, only two increase in size; all the other saltmarshes suffer substantial losses in total area. All combined, these saltmarshes shrunk over 30 ha (≈27%) in the past 70 years. Availability of accommodation space and level of protection seem to be the key factors in saltmarsh resilience. There appears to be a link between the rise of the mean sea-level and the colonization of terrestrial areas, as well as with the disappearance of the saltmarsh islands. The effect of direct human action on the saltmarshes can also be observed in some of the studied areas.

While this is a regional study – mostly intended to understand how the marshes of this area have evolve - it also serves a larger purpose, to emphasize the importance of aerial historical photographs as a source of information about this environment. Unlike other countries, in Portugal aerial photographs are used mostly for coastal erosion assessment, having been used only a couple of times to study marshes. Considering how many estuaries exist in Portugal, and the importance of these areas for the future of our coasts, it is essential to start using all the tools available in their study and in the creation of conservation, naturalization and recovery plans.

This research was funded by Portuguese Foundation for Science and Technology, I.P./MCTES through national funds (PIDDAC) – UIDB/50019/2020 + PTDC/CTA-GEO/28412/2017 and Ph.D. Grants PD/BD/106074/2015 + PD/BD/142781/2018.
New insights into the Last Glacial Maximum in the Maritime Alps from paleoglacier reconstructions and 10Be surface exposure dating
Authors: Rettig Lukas , Kamleitner Sarah , Ivy-Ochs Susan , Monegato Giovanni , Mozzi Paolo , Ribolini Adriano , Rea Brice R. , Ashpitel Lucy , Spagnolo Matteo
Published: June 2022

The valleys of the Maritime Alps (SW European Alps) host a variety of glacial sediments and landforms, and several well-defined moraine ridges have been ascribed to advances that occurred during the Last Glacial Maximum (LGM). Utilising these moraines to reconstruct paleoglacier 3D geometries and their associated Equilibrium Line Altitudes (ELAs) is an excellent method to estimate paleoclimatic parameters, especially if integrated into a solid geochronological framework. Previous studies have been focusing mostly on the catchments of the Gesso and the Stura rivers with other areas receiving less attention. Particularly, chronologically constrained reconstructions of relatively small LGM valley glaciers (in the order of 1-10 km2) are largely lacking, but due to their shorter response times can prove crucial for a better understanding of local and regional paleoclimatic patterns, such as the influence of the proximal Mediterranean Sea on moisture supply during the LGM.

Here, we present new insights into the dynamics of some LGM valley glaciers in the Maritime Alps from three different catchments. These catchments hosted glaciers of varying sizes, aspects, and elevation ranges and are located both on the Italian and French side of the mountain range. Chronological control is provided by 15 new 10Be surface exposure dates, for which samples were taken from boulders on lateral and frontal moraine ridges. Results show that glaciers remained at an advanced position up until around 19 ka. This indicates that climatic conditions, favourable for glacier growth, continued to prevail in the south-western Alps into the latter part of the LGM. Chronologies, reconstructed glacier geometries, and associated ELAs, are presented along with the implications of the findings for our understanding of the LGM paleoclimate.
New geoarchaeological investigation at the Balzi Rossi archaeological area (Ventimiglia, Italy): the contribution of the SPHeritage Project
Authors: Zerboni Andrea ,   SPHeritage Project
Published: June 2022

The main topic of the SPHeritage Project (MUR grant: FIRS2019_00040, P.I.: M. Pappalardo) is an interdisciplinary approach to investigate the human-environment interaction over the last 400,000 years in the Balzi Rossi archaeological area of northern Italy. The well-known archaeological area of ​​the Balzi Rossi represents a unique assemblage of archaeological sites dating to the Palaeolithic, distributed in a geomorphological setting rich of markers of past sea level changes. Moreover, since the Pleistocene the area was a hot spot for climate change and human migrations, thus offering the opportunity to investigate how human populations have responded to past environmental changes and sea level variations. As most of the local archaeological sequences have been extensively investigated at the beginning of the last century and large part of the deposits removed, we will combine the analyses of materials preserved in museums (including undisturbed blocks of archaeological sediments) and the remnants still preserved inside many rockshelters of the archaeological complex. Our approach combines a territorial geomorphological survey and mapping and the application of state-of-the-art geoarchaeological methods to archaeological sequences to disclose the complexity of the human-environmental nexus in the area.
MaxEnt modelling as a tool to inform discovery of deep-sea coral ecosystems
Authors: Nolan Megan K. B. , Marchese Fabio , Kheireddine Malika , Chimienti Giovanni , Purkis Sam , Terraneo Tullia Isotta , Rodrigue Mattie , Eweida Ameer A. , Jones Burton , Benzoni Francesca
Published: June 2022

Coral reefs are now one of the most threatened marine ecosystems, due to local anthropogenic pressures and global changes in ocean conditions. Until recently, research has focused on the vulnerability of shallow coral ecosystems, however effects on deeper coral-dominated ecosystems become more severe with climate change. Deep-sea corals form large bioconstructions, including dense frameworks and mounds, which can remain even when the organisms are dead. The presence of these ecosystems alters the local seafloor morphology. To understand the changes that deep-sea coral ecosystems are undergoing, and the impacts these changes may have on local seafloor morphology, we must first know where they are located. Exploration of deep-sea habitats is costly, challenging and time-consuming, reducing the geographic extent at which it is possible. Methods are also often difficult in remote areas. Therefore, as such ecosystems are relatively sparse, extensive resources may be used attempting to locate them. Species distribution models can be used to identify key areas of interest with much less information, focusing surveys to a smaller extent, and making it much more cost-effective to study. MaxEnt is a habitat suitability modelling software which uses a unique maximum entropy algorithm to find the most dispersed distribution. It requires only presence data, allowing accurate results with less input data. Here we present the first habitat suitability models for deep coral habitats, as deep as 720 m, in the Red Sea. During the OceanX-NEOM ‘Deep Blue’ expedition in the Northern Saudi Arabian Red Sea and the Gulf of Aqaba in 2020, deep-sea coral ecosystems were identified and characterised by ROV and submersible dives. Geomorphometric variables were derived from bathymetry, including measures of aspect, curvature and local-scale rugosity. These variables were used as input data for MaxEnt, along with backscatter, which can provide information about the seafloor substrate, and environmental data from CTD casts and current models. The potential of such models to identify areas of interest is clear, and could become an important tool in order to focus limited conservation funding.
Geotourism activities in the aspiring Geopark Valleys of Cantabria
Authors: Bonachea Jaime , Rivas Victoria , Remondo Juan , González-Díaz Alberto , Cruz-Hernández Pablo , Valenzuela Pablo , Hernández Javier
Published: June 2022

One of the goals of UNESCO Global Geoparks (UGGps) is to contribute to the economic development of the territory by valuing geological heritage and linking it to other natural and cultural resources. Geotourism activities in UGGps are essential to achieve this objective.

Since 2018, within the framework of the European project ATLANTIC GEOPARKS (Interreg Atlantic area programme), the Valleys of Cantabria project is being promoted in order to declare a UGGP in the Cantabria region (Spain). The predominant economic activity in the aspiring territory is the tertiary sector (hotel, catering services and tourism), which is major in coastal areas besides fishing. However, livestock farming still plays a major role in rural and depopulated areas. The declaration of a Geopark would contribute to: (i) setting population and attract visitors to areas at risk to depopulation, and (ii) de-seasonalizing tourism, by offering new geotourism products that may include those linked to the geological, natural and cultural heritage of the region. The aiming goal is to commit to the 17 Sustainable Development Goals (SDGs) of UNESCO's Agenda 2030, establishing synergies with other Geoparks, working with the population living in the area to promote geotourism, and using environmental education as a fundamental element that contributes to knowledge and social awareness.

The proposed geopark has a marked geomorphological character. Due to the existence of a great variety of landscapes and geomorphological landforms, the Valleys of Cantabria territory offers the visitor an assortment of resources related to geotourism, suitable for all audiences. The visitor can enjoy different viewpoints for observing glacial, river, karst or coastal landscapes and several routes of geological interest, which are referred to interpretive panels. It is worth mentioning the rich underground heritage within the area, one of the most important karstic landscapes of Europe and a paradise for speleology activities. To promote and value this resource, new itineraries focusing on the most representative karstic elements have been proposed within the candidacy, including visits to subterranean caves or climbing activities adapted to people with disabilities. A database including all geotouristic activities, with qualified staff, carried out on the aspiring geopark has been created and local companies that offer geotourism activities in the area for enjoying the geological, natural and cultural heritage (interpretative routes to walk or by boat, farm visits, speleology, climbing, canoeing, bird watching or cycling, among others.), have been identified.
Reconstruction of soil erosion and flood variability from Lake Arreo watershed (Northern Spain) during the last millennium
Authors: Corella Juan Pablo , Benito Gerardo , Valero-Garcés Blas L. , Calle Mikel , Stefanova Vania , Millán Rocío , Favre Anne-Catherine , Wilhelm Bruno
Published: June 2022

Mountain regions from Southwestern Europe have been extremely vulnerable to land degradation and soil erosion due to climate factors (summer soil water stress, high storminess and extreme flooding) and to a long history of human use of land impacting these terrestrial ecosystems. The short-time span of instrumental monitoring datasets limits our ability to obtain a full depiction of the long-term drivers controlling soil erosion in Mediterranean watersheds. Here we have applied a novel methodology based on detailed microfacies analyses on lacustrine sediments from Lake Arreo, located in the headwaters of the Ebro Basin (NE Spain), to reconstruct flood variability, annual sediment yield and denudation rates in a mountainous Mediterranean watershed during the last 1400 years.

The Arreo lake record shows that the lowest flood frequency took place during the 6–7th and 10–15th centuries, while higher flood frequency occurred during the 8–9th centuries and the last 500 years. The reconstructed frequency of high-magnitude flood events from the lake record is coherent with the historical cold-season floods from Basque rivers. Fluvial and lacustrine paleoflood records and documentary evidence show abrupt and large increases in extreme flood frequency during the termination of the Little Ice Age (1830–1870 CE) and mid to late 20th century, both periods of Rapid Climate Change (RCC).

The sediment yield values estimated in this study agrees reasonably well with soil erosion rates monitored in Mediterranean experimental watersheds supporting the validity of this methodology to assess the soil erosion and sediment production from a long-term perspective. The highest soil erosion rates correspond to an interplay between increased frequencies and magnitudes of heavy rainfall and intensive agropastoral and forestry activities in the lake's watershed. This study highlights the potential of lacustrine archives to adequately evaluate the environmental drivers and mechanisms controlling land degradation at decadal to centennial time-scales in vulnerable areas to Global Change such as the Mediterranean region.

This study has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement Nº 796752 (FLOODARC).
Automatic geological structure recognition at the Dead Sea lakebed
Authors: AlRabayah Osama , Al-Halbouni Djamil , Watson Robert A. , Caus Danu , Grover Harsh , Nakath David , Rüpke Lars , Weigel Tobias
Published: June 2022

This research aims at developing and applying a machine learning based algorithm to detect geological structural features at the exposed Dead Sea shoreline. We focus on sinkhole, stream-channel and crack features that appear in different material at the coastlines, and post partly a threat for the local population and infrastructure. We use high resolution orthophotos and satellite images from the last years, as well as derived topographic models to reach an automatic identification and classification of these structures. The aim is to train a convolutional neural network that can identify these structures on recent datasets from satellite images in order to establish an automated detection of hazardous and active zones in the area. Furthermore, we use the algorithms to detect structures in the shallow waters of the lake.
Capturing the Role of Soil Moisture in Driving Soft Cliff Erosion Through Terrestrial Laser Scan (TLS) Return Intensity Data
Authors: Teasdale Serena L , Hackney Christopher R , Milan David J , Bennett Georgina L , Parsons Daniel R
Published: June 2022

Characterisation of cliff retreat, especially in soft ‘rocks’ is considered highly problematic and complex where rates of lateral retreat can vary between 1 ma-1 and > 10 ma-1. Limited historical observations, and temporally and spatially variable retreat often mean that the fundamental relationships driving erosion e.g. rainfall intensity, rainfall frequency and localised storm events, are overlooked. Providing the basis for empirical modelling under projected climate change, measurement has traditionally relied upon the use of ground survey, historical maps and aerial photographs. Although these techniques offer insight into cliff top position and shoreline change over extended timescales, they are inappropriately placed to capture short-term, focused rates of change.

Here, we quantify failure across the cliff face with localised volumetric change and spatially distributed surface moisture patterns determined from the return intensity measured by a terrestrial laser scanner (TLS). We conducted repeat TLS surveys at a 200 m site of cliff over a 12 month survey period along the Holderness coastline, UK. We demonstrate how TLS can be used to quantity variations in material grain-size and surface moisture (where TLS return intensity is calibrated to in-situ soil moisture measurements), which in turn, can be used to associate active vs stable areas on the cliff face. This work is aimed at exploring the relationship between surface moisture content and grain size as indicators of stability in coastal cliffs.  It is expected that the outcome of this study will have important implications for the understanding, and future modelling of coastal erosion under predicted climate variability.

 

 
Sustainable development goals, values of geodiversity and geosystem services from a geomorphological perspective
Authors: Zwoliński Zbigniew
Published: June 2022

The Earth is a wonderful place for humans to live. Unfortunately, we easily forget how much it has to offer us in the abiotic and biotic spheres. The abiotic sphere in particular goes unnoticed by humans as the basis for their existence. If today we are faced with vital problems such as climate change, changes in land cover and land use, the drying up of vast areas of land, and increasingly frequent flooding, then we are undoubtedly facing numerous and serious environmental, social, economic and even political challenges. These problems cannot be left to themselves; immediate steps must be taken to act quickly to protect the Earth's surface. Perhaps the Sustainable Development Goals, the assessment and protection of geodiversity and the reasonable management of geosystem services are a way to at least partially solve these issues.

We all have a responsibility to successfully transform the world. Our actions today affect the lives of our children and future generations. Everyone deserves equal opportunities. We can achieve a lot with the Sustainable Development Goals because they are universal and do not leave out anyone or anything. Moreover, the goals are interlinked and interdependent. If we understand this, we realise the need to act on many levels, and this in turn will bring us closer to achieving the harmonious use of the abiotic environment.

A particular attribute of geodiversity is its value expressed in different measures. Among the most important values of geodiversity are intrinsic, economic, functional, cultural, scientific with educational and aesthetic values. Each of these measures of value relates to our planet's unique and invaluable resources, which should be protected through wise management. This balancing of resources is difficult but extremely necessary to preserve our civilisation and biodiversity.

Geosystem services are related to goods and services arising specifically from the Earth's surface and subsurface resources. These services include abiotic components that are important and should be taken into account in the assessment and protection of geodiversity. As for ecosystem services, four main groups can be distinguished: supporting, providing, regulating and cultural.

The aim of this presentation is to find and clarify the sequence between sustainable development goals, geosystem services and geodiversity values and their assessments, especially from a geomorphological perspective.
Fluvial fans and terraces in the foothills of the Eastern Cordillera of Colombia: morphology, sediments, and luminescence ages
Authors: Pupim Fabiano , Breda Caio , Leite Carolina , Del Rio Ian , Gómez Sebastian , Sawakuchi André , Parra Mauricio
Published: June 2022

Alluvial fans and terraces are well developed and preserved in the foothills of the Eastern Cordillera of Colombia, being potential archives of tectonic uplift and climatic variations in a poorly studied tropical region. The main aim of the work is to investigate the evolution of fluvial terraces and alluvial fans in the upper Caqueta river basin. We used Landsat imagens and Copernicus digital elevation model (DEM; GLO-30) to map landforms and optically stimulated luminescence (OSL) dating in quartz grains to estimate burial ages. Our results show that most landforms have an alluvial origin, organized in wide fluvial fans with distinct lobes, at least two terrace levels (7 and 13 m above the river level), and connected incised floodplains along the landscape. The sedimentary facies of the fluvial fans and terraces are dominated by clast-supported massive gravels, with thin layers of coarse-grained sandstones. The modern floodplains are related with braided-like to sinuous channels from up to downstream; gravels dominate their sedimentary facies, but fine sand and mudstones are frequent. This sediment finning from terraces/fans to modern floodplains suggests a significant sediment-to-water discharge ratio change through the late Quaternary. New OSL ages will allow us to estimate the burial ages of the mapped landforms and give new insights into the timing and driving factors related to changes in the fluvial dynamic and landscape evolution of the tropical Andean piedmont. (FAPESP #2020/11047-1)
Geomorphological effects of tropical cyclones in Costa Rica
Authors: Quesada-Román Adolfo
Published: June 2022

Tropical cyclones have repeatedly provoked intense devastation over the course of the last decades, and societal drivers such as unplanned urbanization and the lack of flood risk assessments have worse the problem further. Landslides and floods are frequent hazards linked to tropical cyclones. This is not the exception in Costa Rica, where more than 90% of all disasters are hydrometeorological in nature. Different climatic change scenarios indicate that more and stronger tropical cyclones will affect the North Atlantic Basin, where Central America and the Caribbean lie. This study gathers the different methodologies used to understand the geomorphic effects of tropical cyclones in Costa Rica. This study present geomorphic, hydrological, dendrochronological, and risk assessment approaches that look to reduce the human and economic impacts of tropical cyclones in the Central American country. Finally, this study is a call to apply geomorphic assessments in order elucidate the endogenic and exogenic processes related to tropical cyclones affectation on low latitudes.
Reef morphotype characterization as an effective tool for benthic habitat description: a case study from the Red Sea.
Authors: Ezeta Watts Marta Andrea , Marchese Fabio , Benzoni Francesca
Published: June 2022

Remote sensing studies based on satellite and aerial imagery have generated a good understanding of the distribution of several shallow reefs found along the Arabian coast (Bruckner et al., 2011, Rowlands et al., 2012, Rowlands et al., 2016). However, data concerning the deeper benthic assemblages' spatial distribution, type, and conditions are missing, especially in the central Red Sea. Using high-resolution MBES and video collection, we aim to map, describe and classify the reefs found in Thuwal's coastal area, filling the information gap by producing the first benthic habitat map of this area.

High-resolution bathymetric data were collected using the Norbit iWBMS Multibeam Echosounder, which allowed us to classify the reefs in 12 morphotypes. From those morphotypes, 28 areas were selected for ground-truthing examination using a BlueROV2 equipped with a 4K camera and USBL positioning system to characterize the benthic community.

With the information obtained from the bathymetry data and the ROV video transects, a benthic habitat map for Thuwal's reefs was created, where 23 benthic habitat types were observed.

This research uncovered previously poorly studied reef morphologies in the Red Sea and their benthic composition, demonstrating how different reef communities express a different three-dimensional morphological structure. Moreover, this work will help us improve the understanding of the spatial distribution and condition of benthic communities located on Thuwal's coastline, giving a baseline with the potential to provide fundamental information that can be used for management, conservation, and future research in Saudi Arabia.
UAV applications in humid tropical fluvial geomorphology 
Authors: Granados-Bolaños Sebastián , Surian Nicola , Birkel Christian , Quesada-Román Adolfo , Alvarado Guillermo E.
Published: June 2022

The use of unmanned aerial vehicles (UAVs or “drones”) in geosciences is growing rapidly and is significantly contributing to the geomorphological analysis of diverse landforms and their dynamics in a variety of environments around the world. Specifically, UAVs in geomorphology have proved to be a robust and versatile tool due to their ability to acquire large volumes of high-resolution data in a relatively short time and at low-cost compared to other surveying methods. This technology is evolving rapidly and is becoming each time more relevant for the analysis of surface processes. It allows the rapid mapping of highly dynamic geomorphological features with high-resolution which is particularly useful for the study of fluvial processes. Depending on the environmental conditions and flight parameters, common low-cost (<$3000) commercial UAV models such as the DJI Phantom 4 V.2 used in this research can map over 30 hectares of surface in less than 20 minutes, proving to be a valuable tool for monitoring fluvial processes, especially in tropical humid environments where cloudiness can be an important obstacle for other survey methods such as photogrammetric-piloted airborne missions or satellite imagery. We present the results of the usefulness of UAV technology in fluvial geomorphology with several case studies in diverse humid tropical environments of Costa Rica, Central America.  We illustrate how UAV surveying can acquire high-resolution digital terrain and surface models for hydraulic modeling, geomorphic analysis, and forensic reconstruction of flood events in two urban rivers. We also illustrate how low-altitude photogrammetric flights can detect channel changes with centimetric resolution under dense pristine forest coverage, a challenging environment for monitoring river dynamics. Additionally, we used UAV photogrammetric post-processing for automated analysis of particle size distribution detection in river channels. Finally, we exemplify how this technology can be used for riparian vegetation analysis under diverse conditions. The post-processing of the orthomosaics and surface models allowed to construct high-resolution indexes such as Visible Atmospherically Resistant Index (VARI), vegetation height, Leaf Area Index (LAI), and other datasets for ecological analysis of riverine environments.
The Steinsholtsjökull rockslide and GLOF event in January 1967, in light of ongoing climate change in Iceland.
Authors: Saemundsson Thorsteinn , Ben-Yehoshua Daniel , Smail Nathan , Hjartardóttir Ásta Rut , Wells Greta , Belart Joaquin MC , Toschka Shina
Published: June 2022

On the 15th of January 1967, a rockslide, approximately 20 million m3 in volume, fell from the Mt. Innstihaus on to the Steinsholtsjökull outlet glacier, located on the northern side of the Eyjafjallajökull ice cap in South Iceland. The rockslide fell onto the western side of the glacier and broke up its snout. Part of the rockslide material fell into a proglacial lake, in front of the ice margin, causing a large GLOF down the Steinsholtsdalur valley. Huge amounts of sediments were transported and distributed down valley with the GLOF. It is estimated that the maximum discharge of the flood was around 2100-2700 m3/s, about 20 km downstream. A few years prior to the failure local farmers noticed a ~100 m long fracture in the uppermost part of the slope. The fracture was not visible on the 1945 aerial photographs, but clearly visible as a 100 m long fracture on the 1960 image. The failure occurred in 1967 which gives the maximum age of the surface fracture development of 22 years. The head scarp of the rockslide was around 970 m long and up to 300 m high. The rockslide was initiated after an unusually cold and snowy December month, followed by intensive rainfall, and melting period in the middle part of January.

The rockslide occurred in the end of a relatively warm period, which lasted from 1930s to 1960, where outlet glaciers retreated considerably in Iceland. In front of many of them proglacial lakes were formed. After this warm period, colder climate with readvancing outlet glaciers occurred, but at the end of the 20th century another turning point occurred, with higher temperatures and rapidly retreating outlet glaciers. The existing proglacial lakes expanded and many new were formed in front of the rapidly retreating ice margins.

The Steinsholtsdalur 1967 GLOF, with its catastrophic gravitational mass movement, entirely overprinted the proglacial landscape in the Steinsholtsdalur valley. Similar circumstances as were in the valley prior to the event, are now existing and forming in glacial environments today around present day outlet glaciers, which highlight the urgent need to study and monitor these environments.
Sediment Fingerprinting Tracer Conservativeness: Exploring the In-Channel Soil Properties variability
Authors: García-Comendador Julián , Martínez-Carreras Núria , Fortesa Josep , Company Jaume , Borràs Antoni , Palacio Edwin , Estrany Joan
Published: June 2022

Soil properties' conservative behaviour is essential in sediment tracing research. To compare suspended sediment and soil samples, it is necessary that soil properties remain stable or vary in a predictable way during its transfer from sources to deposition areas. Conservative behaviour of soil properties has been largely focused on the differences in particle size and organic matter. However, in-channel biochemical alterations are also known to occur, but further research is needed considering the wide variety of fluvial regimes. Here is presented an experiment to investigate variations of in-channel soil properties' by using the most common soil properties used as tracers in sediment fingerprinting studies; i.e., colour, fallout radionuclides and geochemical elements. Twenty-eight soil samples collected from different land uses were introduced in an intermittent stream channel of a small Mediterranean catchment. Samples were extracted at different time intervals (i.e. 7, 30, 60, 90, 150, 210, 270 and 365 days) during one year. Results showed that changes on soil properties -average coefficient of variation 8.1 ± 8.8%- were generally lower than its spatial variability within the catchment (average coefficient of variation 16.3 ± 18.5%); being the colour properties the most stable tracers with an average coefficient of variation 2.6 ± 2.2%. The general low variability observed in the investigated soil properties and its strong correlations with specific surface area and carbon content seems to emphasize the role of particle size and organic matter in the conservative behaviour of soil properties. The exploration of in-channel soil properties variability can improve the selection of tracers in future suspended sediment fingerprinting studies in Mediterranean catchments.
Water Crisis in India : An Overview
Authors: Raje Archana
Published: June 2022

Water is essential for life on earth. It is unequally distributed over the earth surface. Water scarcity occurrs due to both natural as well as anthropogenic causes. One of the major regions behind water scarcity is that its demand has increased twice than earlier as the population growing exponentially. Some of the major causes of water  scarcity are over use of water, pollution of water, drought, ground water pollution. Some problems arise because of water scarcity like lack of access to drinking water, diseases, sanitation issues, distruction of habitats. This paper is an attempt to investigate the causes and consequnces of water crisis. The data for present analysis have been obtained form secondary sources and various agencies. The main objective of the present paper is to attempt evaluation of the water resources. Study reveals that water is rapidly becoming scarce resource in India because the demand of water is increasing due to pressure of population and changing consumption pattern. For instance, in some parts of the study area, there is evidence of progressive declined in the water table due to over pumping by the tubewells. The situation is getting alrming year after year. These problems can be solved conjunctive use of surface and ground water. There is urgent need for the development of surface water irrigation where ground water utilization is high.
Identification of wall collapses in abandoned agricultural terraces using Object Based Image Analysis and High-Resolution Topography
Authors: Fernández-Olloqui Gonzalo , Lorenzo-Lacruz Jorge , Lana-Renault Noemí
Published: June 2022

Wall collapses, sometimes accompanied by mass movements, is one of the main degradation processes in long-abandoned agricultural terraces and critically affects the hydrological and geomorphological behaviour of terraced hillslopes (e.g., development of new sediment sources, increasing soil erosion, increasing hydrological connectivity, re-establishment of natural drainage pathways). An efficient monitoring of the spatial and temporal dynamics of wall collapses is fundamental to understand all these processes. However, the identification of terrace wall collapses in the field is a time-consuming task with spatial limitations. In this study, Object Based Image Analysis (OBIA) applied on High-Resolution Topography was used (and evaluated) for detecting wall collapses in terraced hillslopes. The approach, which includes image segmentation and Support Vector Machine classification, was implemented in the Cidacos Valley (Iberian Range, Spain), extensively affected by the abandonment and degradation of agricultural terraces. Point clouds extracted from three different remote data sources (airborne LiDAR, terrestrial LiDAR and airborne photogrammetry) were used to obtain three different digital terrain models (DTM). The low spatial resolution of the DTM derived from airborne LiDAR (1 m pixel size) was not sufficient to detect any terrace wall collapse, which had a median size of 10 m2. The results showed that slope, Sky-View factor, topographic openness and curvature DTM-derivatives produced the best segmentations. Field inventories of wall collapses were used to train the classification algorithm (Support Vector Machine) and validate the results of the OBIA approach. Terrace wall collapses were identified with an Overall Accuracy of 0.80 and a Producer Accuracy of 0.50. The results of the approach and further improvements are discussed. Although promising, the detection of wall collapses in terraced hillslopes using OBIA is challenging, especially when it is compared to the detection of larger scale hillslope geomorphological processes (e.g.: landslides).
Derivation of palaeo-air temperature conditions from past periglacial features
Authors: Uxa Tomáš , Křížek Marek
Published: June 2022

Permafrost repeatedly occurred across central Europe during cold periods of the Pleistocene, as evidenced by a number of past periglacial features that are present in both highland and lowland areas. Many of those periglacial features, such as frost wedges and other kinds of patterned ground, cryoturbations, or pingo scars, have been widely utilized to estimate past air temperature conditions. However, the reconstructions have only relied on temperature thresholds of active periglacial features that are now mostly found in high-latitude periglacial environments. Such empirical interpretations have thus often been considered problematic and of limited validity.

Nevertheless, periglacial features mostly form as a result of recurrent freeze-thaw processes that act within the active layer over permafrost, the base of which is commonly sharply defined and limits the subsurface extent of periglacial features. The active-layer thickness (~depth of maximum annual thaw) usually attains several decimetres to metres, which mainly depends on summer and annual temperature conditions. Since the thickness of palaeo-active layer can be determined based on past periglacial features, it can thus also be used to estimate the temperature conditions that gave rise to an active layer of a given thickness.

Here, we present a novel model we have devised that uses the above principles. The palaeo-mean annual air temperature modelled so far at two lowland sites in the Czech Republic where Last Glacial cryoturbations occur ranged between −7.0±1.9 °C  and −3.2±1.5 °C, and its corresponding decline compared to the 1981–2010 period was between −16.0 °C and −11.3 °C, which agrees well with reconstructions utilizing various palaeo-archives. These initial results are promising and suggest that the model could become a useful tool for reconstructing Quaternary palaeo-air temperatures across vast areas of mid-latitudes and low latitudes where relict periglacial features frequently occur, but their full potential remains to be exploited. Additionally, it could help us refine existing and/or provide new insights into past periglacial environments that cannot be unveiled by other abiotic or biotic indicators.

The research is supported by the Czech Science Foundation, project no. 21-23196S.
Mass wasting processes within the Glafkos gorge, Achaia, Western Greece
Authors: Vgenopoulos Aggelos-Leandros , Koukouvelas Ioannis , Bathrellos George D. , Nikolakopoulos Konstantinos , Skilodimou Hariklia D.
Published: June 2022

Landslide occurrences are physical phenomena that occur worldwide and contribute to the evolution of Earth’s landscape. Their associated consequences can lead to the damage of both the natural and man-made environment. Glafkos Stream originates from the Panachaikon mountains and draining into the Gulf of Patras. It flows from Southeast to Northwest in the Northwest Peloponnesus. This area is considered among the most active tectonic region of the world characterized by significant uplift over the recent period. Moreover, landslide events have occurred many times in this area and have repeatedly caused serious damage at sections of the settlements and at the road network.

The scope of the present study is to examine the landslides across the Glafkos Stream. A number of 34 landslides were studied. The causative and triggering parameters of landslides, the landslides repeatability and reactivation were examined. Additionally, the relation between landslides and faults were studied.
Mapping impact of landslides on glacier dynamics based on medium-resolution satellite data
Authors: Ewertowski Marek , Tomczyk Aleksandra
Published: June 2022

Global climate warming leads to rapid glacier recession and increased activity of other geomorphological processes, like landslides, rockfalls, and debris flows. The question is how these two groups of processes (i.e., glacier dynamics and mass movement activities) are related to each other, and to what extent can they threaten the human population and infrastructure? This study focuses on glacier-landslide interactions trying to develop a workflow for the use of medium-resolution satellite data (Landsat, Sentinel, Aster) for systematic quantification of the response of selected glaciers to additional debris load delivered by landslides on the ice surface. The workflow includes eight main steps: (1) Downloading and verification of glacier outlines from global glaciers databases: Randolph Glacier, GLIMS (Global Land Ice Measurements from Space); WGI (The World Glacier Inventory); (2) Filtering of glacier outlines based on topographic properties of their vicinity: Digital Elevation Models (DEMs) were used to select glaciers located in mountain areas and with slopes situated next to the glacier surface. This step excluded ice caps and ice fields without valley outlets as they are unlikely to be affected by landslides; (3) Identification of available images in Google Earth Engine; (4) masking of clouds and surface water bodies using NDWI (normalised difference water index); (5) Classification of debris-covered and clean ice surface using NDSI (normalised difference snow index); (6) Identification of a time step when the debris arrived onto the glacier surface; (7) quantification of changes in the area covered by debris through time; (8) calculation of displacement of characteristic points. The presented workflow was tested in several glaciers located in different geographic settings where the occurrence of large landslides was identified in previous studies: Svinafelljökull and Morsarjökull (Iceland); Tyndall and Lamplugh glaciers (Alaska); Siachen and Baltoro glaciers, and Barun River and Imja River areas (Himalaya), Zaalai Range (Pamir), Glaciar Leones (Patagonia). The results indicated that based on medium-resolution satellite data, it was possible to identify the presence of landslide deposits and, in most cases, to estimate the approximate period of the landslide event. However, the quantification of displacement of landslide deposits was possible only when there was a distinct difference in reflectance characteristics between glacier surface and debris.

This research was funded by National Science Centre, Poland, project number 2021/42/E/ST10/00186