UAV and GPR Data Integration in Glacier Geometry Reconstruction: A Case Study from Irenebreen, Svalbard

Although measurements of thickness and internal structure of glaciers are substantial for the understanding of their evolution and response to climate change, detailed data about polythermal glaciers, are scarce. Here, we present the first ground-penetrating radar (GPR) measurement data of Irenebreen, and high-resolution DEM and orthomosaic, obtained from unmanned aerial vehicle (UAV) photogrammetry. A combination of GPR and UAV data allowed for the reconstruction of the glacier geometry including thermal structure. We compare different methods of GPR signal propagation speed determination and argue that a common midpoint method (CMP) should be used if possible. Our observations reveal that…

STOP 8: Morphology and arrangement of glaciokarst kettles at Vietalva village

APPLICATION OF UNMANNED AERIAL VEHICLES FOR GLACIER RESEARCH IN THE ARCTIC AND ANTARCTIC

Unmanned aerial vehicles or drones are nowadays widely used in a broad field of scientific and commercial applications. Despite this, it is quite a new method for glacier mapping in polar regions and has a lot of advantages, as well as disadvantages over more classical remote sensing instruments. Here we examine the main issues associated with the application of drones for glacier research from our experience in Iceland, Greenland and the Antarctic. We use DJI Phantom series drones for the obtaining of aerial photographs and produce digital surface models (resolution of 8 – 16 cm) and orthomosaics (resolution of 2 – 4 cm) for glacier mapping. Several issues related to the ground control poi…

Radiolokācijas metodes izmantošana purvu nogulumu pētījumos

Elektroniskā versija nesatur pielikumus

Subglacial topography and thickness of ice caps on the Argentine Islands

AbstractThis study presents the first subglacial topography and ice thickness models of the largest ice caps of the Argentine Islands, Wilhelm Archipelago, West Antarctica. During this study, ground-penetrating radar was used to map the thickness and inner structure of the ice caps. Digital surface models of all studied islands were created from aerial images obtained with a small-sized unmanned aerial vehicle and used for the construction of subglacial topography models. Ice caps of the Argentine Islands cover ~50% of the land surface of the islands on average. The maximum thickness of only two islands (Galindez and Skua) exceeds 30 m, while the average thickness of all islands is only ~5 …

Does glacial environment produce glacial mineral grains? Pro- and supra-glacial Icelandic sediments in microtextural study

Abstract Mineral grains from proglacial and supraglacial sedimentary settings in central south-eastern Iceland are considered in this study and analysed with the use of scanning electron microscope (SEM) techniques. By applying this, it is attempted to answer the key research question of whether quartz grains that come from a glacial-related sedimentary environment are indeed of glacial origin. The study also attempts to provide a linkage between microtextures produced on coarser and finer grains and to verify whether mineral grains from adjacent cryconite holes are similar or different. The preliminary assumption was that the more intense glacial grain record was based on several glacial a…

Mālainās gruntīs iegūto radiolokācijas signālu analīze

Maģistra darbs „Mālainās gruntīs iegūto radiolokācijas signālu analīze” ir veltīts radiolokācijas metodes problemātikai. Radiolokācijas metodes pielietošanas iespējas, metodes un signāla interpretācija mālainās gruntīs līdz šim nav pētītas, kas arī nosaka tēmas aktualitāti. Pētījumā tiek sniegts pētījumu teritorijas ģeoloģiskās uzbūves apraksts, izmantotās pētījumu metodikas apraksts, iegūtie pētījuma rezultāti, kuros ietilpst izpētes objektu ģeoloģiskie griezumi, atsegumi, laboratoriski novērtēts pētīto nogulumu granulometriskais sastāvs, mitrums un grunts fāzu tilpuma daļu attiecība, kā arī ģeofizikālo mērījumu ieraksti, iegūto rezultātu interpretācija, diskusija par iegūtajiem rezultātie…

Detailed subglacial topography and drumlins at the marginal zone of Múlajökull outlet glacier, central Iceland: Evidence from low frequency GPR data

Abstract New ground penetrating radar (GPR) observations on the Mulajokull surge-type outlet glacier, central Iceland, are presented. Overall 10.5 km of GPR profile lines were recorded parallel to the glacier margin in August, 2015. Detailed GPR investigations combined with high-accuracy GPS measurements allowed to build a high-resolution model of the subglacial topography. We provide new evidence of streamlined ridges beneath Mulajokull’s marginal zone interpreted as drumlins and show the location of the upper edge of the drumlin field. This discovery improves understanding of the location, morphology and development of drumlins as other geophysical observations of subglacial bedforms bene…

STOP 6: Morphology, internal structure and texture of inland dunes at the Smilškalni site, Middle Gauja Lowland

High-resolution orthophoto map and digital surface models of the largest Argentine Islands (the Antarctic) from unmanned aerial vehicle photogrammetry

This study presents the first high-resolution orthophoto maps and digital surface models (DSMs) of the largest Argentine Islands, West Antarctica. Aerial surveys with small unmanned aerial vehicle (UAV) were performed in Austral summer, 2018, taking 10,041 aerial photographs. Accuracy requirements were ensured using ground control points (GCPs). A resolution of 3.4 and 6.8 cm/px of orthomosaics and DSMs is reached on average, and the RMS reprojection error is 0.22 m on average. We report the morphometric parameters of surveyed islands and discuss issues related to accuracy and the usage of UAVs in polar conditions. This study demonstrates that small and low cost UAVs can be successfully use…

Radiolokācijas metodes pielietojums eolo nogulumu pētījumos

Darbā ir analizētas radiolokācijas metodes pielietosanas iespējas eolo nogulumu pētījumos. Pētījumā tika veikti radiolokācijas profilēsanas darbi plasā frekvencu diapazonā (75–2000 MHz), iekszemes eolo nogulumu izplatības areālā Valkas novadā. Ir iegūti nogulumu paraugi, noteikts to granulometriskais sastāvs, kā arī dabiskā mitruma daudzums. Aprēķināts radiolokācijas signāla izplatīsanās ātrums ģeoloģiskā griezumā. Izmantojot iegūtos rezultātus, tika izdarīti secinājumi par radiolokācijas metodes lietosanas iespējām eolo nogulumu pētījumos, kā arī par nākotnē pētāmām problēmām.

Mapping of large-scale diapir structures at the paleo-ice tongue bed in western Latvia from geophysical investigations and borehole data

Abstract This study comprises the investigation of the complex and deformed Late Pleistocene sedimentary sequence in western Latvia composed of sandy sediments that are protruded by large-scale clayey silt diapirs and covered by glaciotectonically disturbed discontinuous patches of the Late Weichselian till. We use detailed measurements by ground-penetrating radar (GPR) and electrical resistivity tomography (ERT) combined with borehole data and sedimentological investigations at the Baltic Sea cliffs to map and characterize the large-scale deformation structures and discontinuous till patches. We distinguish the intriguing and previously not detected characteristics of the spatial distribut…

The thermal structure, subglacial topography and surface structures of the NE outlet of Eyjabakkajökull, east Iceland

Abstract This study presents the detailed surveys of the NE outlet of Eyjabakkajokull glacier, East Iceland, from the combination of low-frequency ground penetrating radar (GPR), unmanned aerial vehicle (UAV) and GNSS measurements. Data analyses reveal the complex subglacial topography with a prominent, up to 45-m-deep longitudinal trough in the central part of the outlet that serves as the main trunk for the fast ice flow during the glacier surges. During the last decade (2010–2018), the studied part of the glacier has thinned by 4.37 m/yr on average and the ice margin has retreated ~750 m. We detect a boundary between scatter-free zone and zone of intense scattering near the ice margin an…

Cenas tīrelī iegūto radiolokācijas signālu analīze

Pētījums ir veltīts purvu nogulumos iegūto radiolokācijas signālu analīzei un interpretācijai. Tiek sniegts pētījumu teritorijas ģeoloģiskās uzbūves apraksts, izmantotās pētījumu metodikas apraksts darbā ar 300 MHz antenu sistēmu, analizēta kūdras sadalīsanās pakāpe, pelnainība un dabiskais mitrums. Tāpat ir sniegta detāla iegūto radiolokācijas signālu analīze. Secināts, ka elektromagnētisko viļņu izplatīsanās ātrumu kūdrā nenosaka tikai kūdras mitruma daudzuma izmaiņas. Pētījumos ar radiolokācijas metodi elektromagnētisko viļņu izplatīsanās ātrums kūdras slāņos jānosaka ar augstu precizitāti, izmantojot kopējā viduspunkta metodi.

HIGH-RESOLUTION SURFACE AND BED TOPOGRAPHY MAPPING OF RUSSELL GLACIER (SW GREENLAND) USING UAV AND GPR

Abstract. This study presents the detailed survey of the northern marginal part of Russell Glacier, SW Greenland using the combination of unmanned aerial vehicle (UAV) photogrammetry and low-frequency ground penetrating radar (GPR) measurements. Obtained digital elevation model (DEM) and ice thickness data from GPR data allowed the generation of high precision subglacial topography model. We report uncertainties arising from GPR, GPS, and DEM suggesting sufficient accuracy for the reconstruction of glacier bed topography. GPR data and generated subglacial topography model does not reveal any possible Nye channel that could be incised into the bedrock, however, we were able to detect englaci…

A Brief Review of Ground Penetrating Radar Investigation Results of Ice Caps on Galindez, Winter and Skua Islands (Wilhelm Archipelago, Antarctica) for the Period April 2017 – January 2019

This paper represents results of GPR surveying of the ice caps on Galindez (–64.24716W; –65.24992S), Winter (–64.25954W; –65.24944S) and Skua (–64.26530W; –65.25309S) islands (Wilhelm Archipelago, Antarctica) for the period April 2017 — January 2019. The main objectives were identification of the ice layering, monitoring of interglacial heterogeneities (crevasses, interglacial channels and voids) and measurements of the ice thickness. Methods: Surveying on the glaciers has been done with ground coupled shielded bowtie antenna VIY3-300 (300 MHz) GPR and with air coupled dipole Zond 12-e (75 MHz) antenna system. Monitoring investigation of glacier’s interior has been done with VIY3-300. Zond …

Pētījumi ar ģeoradaru Taurenes apkārtnes smilšu iegulās

Bakalaura darbs „Pētījumi ar ģeoradaru Taurenes apkārtnes smilšu iegulās” ir veltīts radiolokācijas metodes problemātikai. Izvēlētā pētniecības metode – radiolokācijas profilēšana - ir salīdzinoši jauna metode, un tās izmantošanas iespējas un pētniecības metodika līdz šim nav izstrādātas. Minētais nosaka tēmas aktualitāti. Pētījumā tiek sniegta trīs atsevišķu izpētes objektu ģeoloģiskā uzbūve, izmantotās pētījumu metodikas apraksts, iegūtie pētījuma rezultāti, kuros ietilpst izpētes objektu ģeoloģiskie griezumi un atsegumi, laboratoriski novērtēts pētīto nogulumu granulometriskais sastāvs un mitrums, kā arī ģeofizikālo mērījumu ieraksti, iegūto rezultātu interpretācija, diskusija par iegūta…

High-resolution orthophoto map and digital surface models of the largest Argentine Islands (the Antarctic) from unmanned aerial vehicle photogrammetry

This study presents the first high-resolution orthophoto maps and digital surface models (DSMs) of the largest Argentine Islands, West Antarctica. Aerial surveys with small unmanned aerial vehicle (UAV) were performed in Austral summer, 2018, taking 10,041 aerial photographs. Accuracy requirements were ensured using ground control points (GCPs). A resolution of 3.4 and 6.8 cm/px of orthomosaics and DSMs is reached on average, and the RMS reprojection error is 0.22 m on average. We report the morphometric parameters of surveyed islands and discuss issues related to accuracy and the usage of UAVs in polar conditions. This study demonstrates that small and low cost UAVs can be successfully use…