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…

The Raunis section, central Latvia, revisited: first luminescence results and re-evaluation of a key Baltic States stratigraphic site

This is an Accepted Manuscript version of the following article: Kalińska, E., Alexanderson, H. & Krievāns, M. (2020). The Raunis section, central Latvia, revisited: first luminescence results and re-evaluation of a key Baltic States stratigraphic site. Geografiska Annaler: Series A, Physical Geography, 102(4), 376-396. It is deposited under the terms of the Creative Commons Attribution-NonCommercial License, which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. In interstadial deposits, sand interbeds gain limited consideration in comparison with organic sediments, and therefore tend to be underrepresented in paleoe…

Seismites resulting from high-frequency, high-magnitude earthquakes in Latvia caused by Late Glacial glacio-isostatic uplift

Abstract Geologically extremely rapid changes in altitude by glacial rebound of the Earth crust after retreat of the Scandinavian Ice Sheet at the end of the last Weichselian glaciation influenced the palaeogeography of northern Europe. The uplift of the Earth crust apparently was not gradual, but shock-wise, as the uplift was accompanied by frequent, high-magnitude earthquakes. This can be deduced from strongly deformed layers which are interpreted as seismites. Such seismites have been described from several countries around the Baltic Sea, including Sweden, Germany and Poland. Now similarly deformed layers that must also be interpreted as seismites, have been discovered also in Latvia, a…

Driasa un holocēna nogulumi Abavas vidustecē un to paleontoloģiskais raksturojums

Bakalaura darbā ir interpretēti ledus laikmeta beigu posma un holocēna sākuma paleoekoloģiskie apstākļi Abavas Rumbas apkārtnē pēc paleoentomoloģiskajiem un paleokarpoloģiskajiem datiem. Pētījums tika veikts Talsu rajona Sabiles novadā 200 m lejpus Abavas Rumbai, upes labajā krastā. Teorētiskajā daļā apkopoti dati par ledus laikmeta beigu posma un holocēna nogulumiem Latvijā un to stratigrāfisko iedalījumu, kā arī Abavas – Slocenes ielejas ģeomorfoloģisko attīstību un iepriekšējiem pētījumiem Abavas Rumbas griezumā. Pētījuma gaitā ievākti 15 paraugi, no kuriem apstrādāti 12 (katrs ne mazāk kā 3 – 5 kg smags). Atlasīti vairāki tūkstoši augu, kukaiņu, aļģu un citas atliekas, pēc kurām veikta …

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 …

STOP 1: Lower Gauja spillway valley at Sigulda

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…

Rauņa ielejas morfoloģija un attīstība leduslaikmeta beigu posmā un pēcleduslaikmetā

Maģistra darbā veikts pētījums par Rauņa ielejas attīstību leduslaikmeta beigu posmā un pēcleduslaikmetā. Darba teorētiskajā daļā apzināti agrāk veikto pētījumu rezultāti, kas atspoguļo dažādus viedokļus par Rauņa ielejas apkaimes ģeoloģisko uzbūvi un attīstību. Darbs balstīts uz autora veiktajiem lauka pētījumiem, radioaktīvā oglegļa, lielmēroga (M 1:10 000) topogrāfisko karšu un autora izstrādātā digitālā zemes virsmas modeļa datiem. Iegūtie rezultāti apstrādāti ArcMap vidē. Pētījuma rezultātā iegūti jauni, augstas precizitātes dati par Rauņa ielejas morfoloģiju un attīstību. Tie ļauj izdarīt secinājumu, ka Rauņa ieleja ir salikts veidojums, un tās atsevišķi posmi un ar tiem saistītās gra…

STOP 3: Late-glacial and early postglacial environmental processes and the history of the River Triečupīte valley and surroundings, in the foreland of the Vidzeme Upland

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…

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…

STOP 5: Veselava end moraine, north-western Vidzeme Upland

An erratic dropstone of granodiorite with a water-escape structure from a Weichselian terrace along the River Gauja (NE Latvia)

Abstract A river terrace of the River Gauja (Latvia), built of Weichselian glaciolacustrine deposits, contains a large number of erratic boulders from the Fennoscandian Shield. These erratic boulders include several types of granites and granodiorites. Some of the granodiorites are so strongly weathered that they fall apart into mm-sized grains of individual minerals when it is attempted to take them out of the host sediment. This strongly weathered nature makes them physically comparable to unconsolidated sand. A consequence is that they may be subjected to soft-sediment deformation. The erratic granodiorite boulder under study here is the first described to show such a soft-sediment defor…

STOP 4: Internal structure and genesis of the sediments underlying Terrace III of the River Gauja at Dukuļi farmhouse and Valmiera town

STOP 7: Madona-Trepe ice-marginal ridge at Smeceres sils, East-Latvian Lowland

Hidrogrāfiskā tīkla veidošanās lejas Gaujas senielejai pieguļošajā teritorijā vēlā Vislas apledojuma deglaciācijas laikā

Elektroniskā versija nesatur pielikumus

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 …

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…