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

Abstract

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 Irenebreen is a polythermal glacier with a basal temperate ice layer, the volume of which volume reaches only 12% of the total glacier volume. We also observe the intense GPR signal scattering in two small zones in the ablation area and suggest that intense water percolation occurs in these places creating local areas of temperate ice. This finding emphasizes the possible formation of localised temperate ice zones in polythermal glaciers due to the coincidence of several factors. Our study demonstrates that a combination of UAV photogrammetry and GPR can be successfully applied and should be used for the high-resolution reconstruction of 3D geometries of small glaciers.

3D Sedimentary Architecture of Sandy Braided River, Based on Outcrop, Unmanned Aerial Vehicle and Ground Penetrating Radar Data

“…The present tectonic framework of the basin is the result of the late Indosinian movements [20]. The basin developed over 200 m of Lower Jurassic braided river deposits in unconformable contact with the underlying Paleozoic marine strata and is overlain by Middle to Upper Jurassic lacustrine deposits [21]. The fluvial deposits in the studied outcrop area are located between the mountain range in the northwest and the lacustrine basin in the southeast, and the braided river extends from the alluvial fan to the middle of the basin, 20 km away from the northwest mountain range and more than 100 km away from the southeast lake [22].…”

“…The fluvial deposits in the studied outcrop area are located between the mountain range in the northwest and the lacustrine basin in the southeast, and the braided river extends from the alluvial fan to the middle of the basin, 20 km away from the northwest mountain range and more than 100 km away from the southeast lake [22]. The Yungang Formation is divided into three lithologic members, which are the Conglomerate Member, the Rockcave Member and the Mudstone Member from bottom to top [21,22]. The Conglomerate Member contains grey conglomerate intercalated sandstone, with a thickness of less than 40 m. The Rockcave Member comprises red coarse sandstone and a small amount of red mudstone.…”

“…In this study, the features of the sedimentary architecture are controlled by the bed form and boundary of the channel. The description of braided river sedimentary architectural elements based on outcrop observation and the previous division scheme are shown in Table 1 [13,21,29,[32][33][34][35][36][37]. Architectural elements can be divided into three types: Channel unit, bar unit and overbank assemblages.…”

Evidences of Bedrock Forcing on Glacier Morphodynamics: A Case Study in Italian Alps

“…This is slightly smaller than the uncertainty of ±0.008 m ns −1 assumed by Lapazaran et al (2016), as they applied it to polythermal ice. This uncertainty could be further reduced by measuring the propagation velocity on-site by conducting CMP measurements (Bradford and Harper, 2005) or by analyzing the shape of diffraction hyperbolas in the GPR data (Karušs et al, 2022). This was not possible in our case, because CMP measurements have to be conducted on the ground, whereas no clean diffraction hyperbolas were present in our data.…”

Investigation of buried karst sinkholes under a bog using ground penetrating radar (GPR) and electrical resistivity tomography (ERT)

“…During the processing of the timedependent gain, the Background removal and Ormsby bandpass filters were used. To determine the EM wave propagation speed, a common midpoint method (CMP) was applied (Karušs et al, 2021(Karušs et al, , 2022Karušs & B erzin ¸š, 2015;Neal, 2004) using a 300 MHz antenna as a transmitter and a 500 MHz antenna as a receiver. The exact positions of the CMP measurement points were chosen using common offset radargrams.…”