Object-Based Geomorphological Mapping: Application on an Alpine Deep-Seated Gravitational Slope Deformation Contest (Germanasca Valley, Western Alps—Italy)

This research reports the use of a new method of geomorphological mapping in GIS environments, using a full-coverage, object-based method, following the guidelines of the new geomorphological legend proposed by ISPRA–AIGEO–CNG. This methodology is applied to a tributary valley of the Germanasca Valley, shaped into calcschist and greenschist, of the Piedmont Zone (Penninic Domain, Western Alps). The investigated sector is extensively affected by dep-seated gravitational slope deformation (DSGSD) that strongly influences the geological setting and the geomorphological features of the area. The mapping of these gravitational landforms in a traditional way creates some difficulties, essentially connected to the high density of information in the same site and the impossibility of specifying the relationships between different elements. The use of the full-coverage, object-based method instead is advantageous in mapping gravitational evidence. In detail, it allows for the representation of various landforms in the same sector, and their relationships, specifying the size of landforms, and with the possibility of multiscale representation in the GIS environment; and, it can progressively be update with the development of knowledge. This research confirms that the use of the full-coverage, object-based method allows for better mapping of the geomorphological features of DSGSD evidence compared to classical representation.

Submarine Geomorphological Features and Their Origins Analyzed from Multibeam Bathymetry Data in the South China Sea

We processed the raw multi-beam bathymetry data acquired in the central and northeastern part of the South China Sea by eliminating noise and abnormal water depth values caused by environmental factors, and a high resolution bathymetric map with a 20-m grid interval was constructed. Various scales of seafloor geomorphological features were identified from the data, including an image of Shenhu canyon, which is located in the northern continental margin of the South China Sea; submarine reticular dunes in the north of the Dongsha atoll; submarine parallel dunes in the northeast of the Dongsha atoll; and several seamounts in the southwest sub-basin and in the east sub-basin. In the processing step, various anomalies in the multi-beam bathymetry data were corrected. The optimal swath filtering and surface filtering methods were chosen for different scales of seafloor topography in order to restore the true geomorphological features. For the large-scale features with abrupt elevation changes, such as seamounts (heights of ~111–778 m) and submarine canyons (incision height of ~90–230 m), we applied swath filtering to remove noise from the full water depth range of the data, and then surface filtering to remove small noises in the local areas. For the reticular dunes and parallel dunes (heights of ~2–32 m), we applied only surface filtering to refine the data. Based on the geometries of the geomorphological features with different scales, the marine hydrodynamic conditions, and the regional structure in the local areas, we propose that the Shenhu submarine canyon was formed by turbidity current erosion during the Sag subsidence and the sediment collapse. The submarine reticular dunes in the north of the Dongsha atoll were built by the multi-direction dominant currents caused by the previously recognised internal solitary waves around the Dongsha atoll. The submarine parallel dunes in the northeast of the Dongsha atoll were built by the repeated washing of sediments with the influence of the tidal currents and internal solitary waves. The conical, linear and irregular seamounts identified from the bathymetry data were formed during the spreading of the southwest sub-basin and the east sub-basin. The identified seamounts in the multi-beam bathymetry data are correlated to deep magmatic activities, the Zhongnan transform fault and the NE-trending faults.

Design of telescopic nadir imager for geomorphology (TENGOO) and observation of surface reflectance by optical chromatic imager (OROCHI) for the Martian Moons Exploration (MMX)

The JAXA’s Martian Moons Exploration (MMX) mission is planned to reveal the origin of Phobos and Deimos. It will remotely observe both moons and return a sample from Phobos. The nominal instruments include the TElescopic Nadir imager for GeOmOrphology (TENGOO) and Optical RadiOmeter composed of CHromatic Imagers (OROCHI). The scientific objective of TENGOO is to obtain the geomorphological features of Phobos and Deimos. The spatial resolution of TENGOO is 0.3 m at an altitude of 25 km in the quasi-satellite orbit. The scientific objective of OROCHI is to obtain material distribution using spectral mapping. OROCHI possesses seven wide-angle bandpass imagers without a filter wheel and one monochromatic imager dedicated to the observation during the landing phase. Using these two instruments, we plan to select landing sites and obtain information that supports the analysis of return samples. Graphical Abstract

Chronology of sedimentation in Colesbukta, Spitsbergen (Svalbard Archipelago): the results of the 2018 expedition

This paper presents results of a study of sedimentation in Colesbukta (Isfjorden, Spitsbergen), a typical example of sedimentation in a shallow bay of the Svalbard Archipelago. We have examined sediment samples from several cores collected in Colesbukta in May 2018. To meet the goals of this study, geomorphological features of the Colesbukta catchment area have been identified and described. The lithological characteristics of bottom sediments from the study area have been described and their spatial and temporal changes analyzed. The chronology of sedimentation has been reconstructed by 210Pb and 137Cs. We have calculated sedimentation rates in Colesbukta and their temporal dynamics over the several latest decades. According to our estimations, the sedimentation rate has increased by 2–4 times compared to the middle of the 20th century and ranges from 0.2 to 0.46 mm/year depending on the individual conditions of sedimentation in each part of the bay. Climatic fluctuations are shown to have a direct impact on sedimentation processes in Colesbukta. We have revealed that on the periphery of the studied area the rate of sedimentation better depends on the temperature regime while in its central part it is rather a result of the amount of atmospheric precipitation.

PETROGRAPHIC FEATURES AND MODELLING OF SOME WATERFALL ROCKS IN KENYIR LAKE, TERENGGANU: A MICROSCOPIC PERSPECTIVE APPROACH IN SUSTAINABLE GEOTOURISM

Waterfalls around Kenyir Lake, Terengganu naturally serve as an iconic symbol of amazing rock bounded formation amidst the wilderness, which stores a hidden story for millions of years. The waterfalls feeding the Kenyir Lake have become tourists’ main attractions since they are located separately on a different island. There are three naturally picturesque waterfalls worth seeing in the study area, namely Sungai Buweh Waterfall, Lasir Waterfall, and Saok Waterfall, which are made up of granitic rock body that emerged in the Eastern Belt during the Late Triassic (~251.2 Ma). To date, the waterfall landscape in any area concerned with geotourism focusses more on outcrop architecture and geomorphological features, but has only limited accessibility to rock records. This study was carried out to evaluate the geo heritage features, of the waterfall landscape as well as its rock-forming minerals. Three rock samples were carefully collected from the waterfalls and subsequently prepared for optical thin section petrography analysis using a polarised light microscope. The optical thin section petrography further revealed precise mineral compositions, fabrics, and microstructures. A photomicrograph of the thin sections was also taken at low and high magnification levels in plane polarised light (PPL) and cross polarised light (XPL). Additionally, petrographic modelling was constructed using optical microscopic data to help identify a microscopic mineral (a hidden material in rock) in detail so that the mineral becomes clear to both geologists and the public at large. Generally, this modelling will enlighten the public on the material embedded in the rocks and illustrate the importance of learning about rock-forming minerals as well as to embed the idea of making the waterfall a Sustainable Development Goal (SDG). Besides making geology an interesting field to embark on, this mineral find affirms the beauty of the waterfalls for tourism purposes, thereby connecting geotourism and nature. The minerals from various constituents are also useful for scientific heritage purposes and may benefit the economy by serving as sustainable tourism while being part of a geopark.

Ice volume and basal topography estimation using geostatistical methods and ground-penetrating radar measurements: application to the Tsanfleuron and Scex Rouge glaciers, Swiss Alps

Ground-penetrating radar (GPR) is widely used for determining mountain glacier thickness. However, this method provides thickness data only along the acquisition lines, and therefore interpolation has to be made between them. Depending on the interpolation strategy, calculated ice volumes can differ and can lack an accurate error estimation. Furthermore, glacial basal topography is often characterized by complex geomorphological features, which can be hard to reproduce using classical interpolation methods, especially when the field data are sparse or when the morphological features are too complex. This study investigates the applicability of multiple-point statistics (MPS) simulations to interpolate glacier bedrock topography using GPR measurements. In 2018, a dense GPR data set was acquired on the Tsanfleuron Glacier (Switzerland). These data were used as the source for a bedrock interpolation. The results obtained with the direct-sampling MPS method are compared against those obtained with kriging and sequential Gaussian simulations (SGSs) on both a synthetic data set – with known reference volume and bedrock topography – and the real data underlying the Tsanfleuron Glacier. Using the MPS modeled bedrock, the ice volume for the Scex Rouge and Tsanfleuron glaciers is estimated to be 113.9 ± 1.6 million cubic meters. The direct-sampling approach, unlike the SGS and kriging, allowed not only an accurate volume estimation but also the generation of a set of realistic bedrock simulations. The complex karstic geomorphological features are reproduced and can be used to significantly improve for example the precision of subglacial flow estimation.

Morphological Significance and Relation of Ecosystems of Submarine Canyons off SW Taiwan

There are four shelf-incising submarine canyons off SW Taiwan. They are distributed along the active continental margin, which is periodically flushed by gravity flows. Shelf-incising canyons, such as Kaoping Canyon, may not only be affected by oceanographic conditions but also by extreme climate change due to the direct input of river sediment. In the canyons along the SW margin of Taiwan, strong sedimentary flows are reflected in highly abundant nutrient input and physical disturbances. The Kaoping Canyon possesses habitats that promote biodiversity but that are sensitive to environmental change. The aims of this study are to review the canyons along the SW margin of Taiwan and to present their geomorphological features and associated ecosystems.

Identification And Characterization Of Geoheritage Resources At Hulu Langat, Selangor

Identification and characterization of geodiversity for sites need more systematic approach for the purpose of conserving site with high geoheritage value. The present of igneous and metamorphic rock at Hulu Langat creates diversity in rock, features and geomorphological features includes hot spring, waterfall, hill and mountain that hold potential as a protected geosite of heritage value. Besides, the previous tin mining activities created by the contact metamorphism, left series of lakes and ponds while the nearby mountain is susceptible area as watershed that turn into dams around the area. Analysis on topographical maps, satellite image and aerial photograph interpretation aided in identification potential geosite based on geomorphological diversity. A total of 31 potential geosites with geological-scientific value have been identified in this study compare to 10 from the previous study. The potential geosite have been classified into rock diversity, natural landscape diversity and anthropogenic landscape diversity. Characterisation recognise 6 of these potential geosite are best example or tip location to illustrate the geological element, 4 of these geosites are the only occurrence of the geological element, 27 of the potential geosites are well preserved and 4 hold the scientific knowledge written in the international journal. The identification and characterisation of geoheritage resources are crucial steps before evaluation or assessment, ranking and conservation or development being propose, while strengthen the conservation geology approach.