TY - JOUR A1 - Allroggen, Niklas A1 - Tronicke, Jens T1 - Attribute-based analysis of time-lapse ground-penetrating radar data JF - Geophysics N2 - Analysis of time-lapse ground-penetrating radar (GPR) data can provide information regarding subsurface hydrological processes, such as preferential flow. However, the analysis of time-lapse data is often limited by data quality; for example, for noisy input data, the interpretation of difference images is often difficult. Motivated by modern image-processing tools, we have developed two robust GPR attributes, which allow us to distinguish amplitude (contrast similarity) and time-shift (structural similarity) variations related to differences between individual time-lapse GPR data sets. We tested and evaluated our attributes using synthetic data of different complexity. Afterward, we applied them to a field data example, in which subsurface flow was induced by an artificial rainfall event. For all examples, we identified our structural similarity attribute to be a robust measure for highlighting time-lapse changes also in data with low signal-to-noise ratios. We determined that our new attribute-based workflow is a promising tool to analyze time-lapse GPR data, especially for imaging subsurface hydrological processes. Y1 - 2016 U6 - https://doi.org/10.1190/GEO2015-0171.1 SN - 0016-8033 SN - 1942-2156 VL - 81 SP - H1 EP - H8 PB - Society of Exploration Geophysicists CY - Tulsa ER - TY - JOUR A1 - Elling, Felix J. A1 - Spiegel, Cornelia A1 - Estrada, Solveig A1 - Davis, Donald W. A1 - Reinhardt, Lutz A1 - Henjes-Kunst, Friedhelm A1 - Allroggen, Niklas A1 - Dohrmann, Reiner A1 - Piepjohn, Karsten A1 - Lisker, Frank T1 - Origin of Bentonites and Detrital Zircons of the Paleocene Basilika Formation, Svalbard JF - Frontiers in Earth Science N2 - The Paleocene was a time of transition for the Arctic, with magmatic activity of the High Arctic Large Igneous Province (HALIP) giving way to magmatism of the North Atlantic Large Igneous Province in connection to plate tectonic changes in the Arctic and North Atlantic. In this study we investigate the Paleocene magmatic record and sediment pathways of the Basilika Formation exposed in the Central Tertiary Basin of Svalbard. By means of geochemistry, SmNd isotopic signatures, and zircon UPb geochronology we investigate the characteristics of several bentonite layers contained in the Basilika Formation, as well as the provenance of the intercalated clastic sediments. Our data show that the volcanic ash layers of the Basilika Formation, which were diagenetically altered to bentonites, originate from alkaline continental-rift magmatism such as the last, explosive stages of the HALIP in North Greenland and the Canadian Arctic. The volcanic ash layers were deposited on Svalbard in a flat shelf environment with dominant sediment supply from the east. Dating of detrital zircons suggests that the detritus was derived from Siberian sources, primarily from the Verkhoyansk Fold-and-Thrust Belt, which would require transport over similar to 3000 km across the Arctic. KW - Paleogene KW - Svalbard KW - Central Tertiary Basin KW - Basilika formation KW - bentonite KW - zircon provenance KW - High Arctic Large Igneous Province KW - North Atlantic Large Igneous Province Y1 - 2016 U6 - https://doi.org/10.3389/feart.2016.00073 SN - 2296-6463 VL - 4 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Schennen, Stephan A1 - Tronicke, Jens A1 - Wetterich, Sebastian A1 - Allroggen, Niklas A1 - Schwamborn, Georg A1 - Schirrmeister, Lutz T1 - 3D ground-penetrating radar imaging of ice complex deposits in northern East Siberia JF - Geophysics N2 - Ice complex deposits are characteristic, ice-rich formations in northern East Siberia and represent an important part in the arctic carbon pool. Recently, these late Quaternary deposits are the objective of numerous investigations typically relying on outcrop and borehole data. Many of these studies can benefit from a 3D structural model of the subsurface for upscaling their observations or for constraining estimations of inventories, such as the local carbon stock. We have addressed this problem of structural imaging by 3D ground-penetrating radar (GPR), which, in permafrost studies, has been primarily used for 2D profiling. We have used a 3D kinematic GPR surveying strategy at a field site located in the New Siberian Archipelago on top of an ice complex. After applying a 3D GPR processing sequence, we were able to trace two horizons at depths below 20 m. Taking available borehole and outcrop data into account, we have interpreted these two features as interfaces of major lithologic units and derived a 3D cryostratigraphic model of the subsurface. Our data example demonstrated that a 3D surveying and processing strategy was crucial at our field site and showed the potential of 3D GPR to image geologic structures in complex ice-rich permafrost landscapes. Y1 - 2016 U6 - https://doi.org/10.1190/GEO2015-0129.1 SN - 0016-8033 SN - 1942-2156 VL - 81 SP - WA195 EP - WA202 PB - Society of Exploration Geophysicists CY - Tulsa ER -