Pointcatcher software:analysis of glacial time-lapse photography and integration with multi-temporal digital elevation models

Terrestrial time-lapse photography offers insight into glacial processes through high spatial and temporal resolution imagery. However, oblique camera views complicate measurement in geographic coordinates, and lead to reliance on specific imaging geometries or simplifying assumptions for calculating parameters such as ice velocity. We develop a novel approach that integrates time-lapse imagery with multi-temporal digital elevation models to derive full 3D coordinates for natural features tracked throughout a monoscopic image sequence. This enables daily independent measurement of horizontal (ice flow) and vertical (ice melt) velocities. By combining two terrestrial laser scanner surveys with a 73-day sequence from Sólheimajökull, Iceland, variations in horizontal ice velocity of ~10% were identified over timescales of ~25 days. An overall surface elevation decrease of ~3.0 m showed rate changes asynchronous with the horizontal velocity variations, demonstrating a temporal disconnect between the processes of ice surface lowering and mechanisms of glacier movement. Our software, ‘Pointcatcher’, is freely available for user-friendly interactive processing of general time-lapse sequences and includes Monte Carlo error analysis and uncertainty projection onto DEM surfaces. It is particularly suited for analysis of challenging oblique glacial imagery, and we discuss good features to track, both for correction of camera motion and for deriving ice velocities

Holocene glacial history of Svalbard: Status, perspectives and challenges

© 2020 The Author(s) We synthesize the current understanding of glacier activity on Svalbard from the end of the Late Pleistocene (12,000 yrs. before present) to the end of the Little Ice Age (c. 1920 AD). Our glacier history is derived from the SVALHOLA database, the first compilation of Holocene geochronology for Svalbard and the surrounding waters, including over 1,800 radiocarbon, terrestrial cosmogenic nuclide and optically stimulated luminescence ages. Data have been categorized by geological setting, uniformly (re-)calibrated, quality assessed and ultimately used to constrain glacier fluctuations (deglaciation, ice free conditions, glacier re-advances and ice marginal positions). We advance existing knowledge by mapping the extent and distribution of ice-cover during the Holocene glacial maximum and the glacial minimum, as well as present retreat rates (and percentages) within Early Holocene fjord-systems. Throughout the Holocene, Svalbard glaciers have responded to a varying combination of climatic, environmental and dynamic driving factors which influence both the extent and behavior of ice margins. We discuss the complexities of glacier systems and their dynamics in response to changes in climate. This review provides a holistic state of the art of Holocene glaciers on Svalbard, suitable for orienting future works which address gaps in our current knowledge

Geomorphology and surficial geology of the Femmilsjøen area, northern Spitsbergen

Climate change is amplified in the Arctic, and establishing baseline data for its current character is important. Here we present a map of the geomorphology of the Femmilsjøen area, Spitsbergen, northern Svalbard. The regional physiography is characterised by a low-relief, high elevation mountain plateau, its high-relief steep slopes, and low-relief coastal lowlands. The results indicate that glaciers were most likely warm-based and erosive in the low terrain, whereas there are signatures of colder, less erosive ice on the plateaus during the Late Weichselian. Our study highlights the ongoing glacial and periglacial morphological processes in an area of hard and weathering-resistant bedrock, situated in northern Svalbard

Glacial history of the Åsgardfonna Ice Cap, NE Spitsbergen, since the last glaciation

The response of glaciers and ice caps to past climate change provides important insight into how they will react to ongoing and future global warming. In Svalbard, the Holocene glacial history has been studied for many cirque and valley glaciers. However, little is known about how the larger ice caps in Svalbard responded to Late Glacial and Holocene climate changes. Here we use lake sediment cores and geophysical data from Femmilsjøen, one of Svalbard’s largest lakes, to reconstruct the glacial history of the Åsgardfonna Ice Cap since the last deglaciation. We find that Femmilsjøen potentially deglaciated prior to 16.1 ± 0.3 cal ka BP and became isolated from the marine environment between 11.7 ± 0.3 to 11.3 ± 0.2 cal ka BP. Glacial meltwater runoff was absent between 10.1 ± 0.4 and 3.2 ± 0.2 cal ka BP, indicating that Åsgardfonna was greatly reduced or disappeared in the Early and Middle Holocene. Deposition of glacial-meltwater sediments re-commenced in Femmilsjøen at c. 3.2 ± 0.2 cal ka BP, indicating glacier re-growth in the Femmilsjøen catchment and the onset of the Neoglacial. The glacier(s) in the Femmilsjøen catchment area reached sizes no smaller than their modern extents already at c. 2.1 ± 0.7 cal ka BP. Our results suggest that larger Svalbard ice caps such as Åsgardfonna are very sensitive to climate changes and probably melted completely during the Holocene Thermal Maximum. Such information can be used as important constraints in future ice-cap simulations

Postglacial relative sea level change and glacier activity in the early and late Holocene:Wahlenbergfjorden, Nordaustlandet, Svalbard

Publisher's version (útgefin grein).Sediment cores from Kløverbladvatna, a threshold lake in Wahlenbergfjorden, Nordaustlandet, Svalbard were used to reconstruct Holocene glacier fluctuations. Meltwater from Etonbreen spills over a threshold to the lake, only when the glacier is significantly larger than at present. Lithological logging, loss-on-ignition, ITRAX scanning and radiocarbon dating of the cores show that Kløverbladvatna became isolated from Wahlenbergfjorden c. 5.4 cal. kyr BP due to glacioisostatic rebound. During the Late Holocene, laminated clayey gyttja from lacustrine organic production and surface runoff from the catchment accumulated in the lake. The lacustrine sedimentary record suggests that meltwater only spilled over the threshold at the peak of the surge of Etonbreen in AD 1938. Hence, we suggest that this was the largest extent of Etonbreen in the (mid-late) Holocene. In Palanderbukta, a tributary fjord to Wahlenbergfjorden, raised beaches were surveyed and organic material collected to determine the age of the beaches and reconstruct postglacial relative sea level change. The age of the postglacial raised beaches ranges from 10.7 cal. kyr BP at 50 m a.s.l. to 3.13 cal. kyr BP at 2 m a.s.l. The reconstructed postglacial relative sea level curve adds valuable spatial and chronological data to the relative sea level record of Nordaustlandet.Sveinn Brynjólfsson and Sara Mollie Cohen are thanked for field assistance. Fieldwork and radiocarbon dates were funded by the Carlsberg Foundation (CF14-0756 to Schomacker) and Department of Arctic Geology, The University Centre in Svalbard (UNIS), respectively. Geospatial support was provided by the Polar Geospatial Center, and DEM(s) were created from DigitalGlobe, Inc., imagery and funded under National Science Foundation awards 1043681, 1559691, and 1542736. We thank Ole Bennike, Svend Funder, Antony Ruter, and Peter Ilsøe for macrofossil identification and lab assistance. The manuscript benefited from constructive review comments from Andy Emery. The publication charges for this article have been funded by a grant from the publication fund of UiT The Arctic University of Norway.Peer Reviewe

Identificação, dinâmica da produção e potencial de uso do feromônio de agregação de Pseudopiazurus obesus (Boheman, 1838) (Coleoptera : Curculionidae)

Orientador : Paulo H.G. ZarbinDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Ciências Biológicas (Entomologia). Defesa: Curitiba, 2005Inclui bibliografiaÁrea de concentraçao: EntomologiaResumo: A pesquisa objetivou identificar, determinar a dinâmica da produção e avaliar o potencial de uso do feromônio de agregação de Pseudopiazurus obesus (Boheman, 1838), (Coleoptera: Curculionidae), visando à possibilidade do uso desta alternativa no monitoramento e controle desta praga. O estudo consistiu em três fases, sendo a primeira envolvendo a criação dos insetos; a segunda a obtenção dos voláteis dos insetos e avaliação destes no comportamento dos co-específicos e a terceira abrangendo isolamento, identificação e avaliação da atividade biológica do feromônio sintético em laboratório. Ações complementares de pesquisa ainda foram desenvolvidas como a determinação da dinâmica da produção do feromônio e avaliação da captura dos espécimes em armadilhas a campo. Os principais resultados foram: machos e fêmeas são mais atraídos para voláteis de insetos machos adicionado a partes da planta hospedeira (caule fresco do mamoeiro), sugerindo ação sinergística e potencializando a atratividade de co-específicos; a liberação do feromônio inicia a partir do 18o DAE (dias após a emergência) e ocorre durante a escotofase, sendo observado o pico de produção 4 - 6 h após o seu início; machos virgens e acasalados são semelhantes quanto à produção de feromônio e esta é dependente da planta hospedeira; a duração da produção ocorre até aos 105 DAE; o feromônio é do tipo agregação; grandisal, grandisol e papaianol (composto majoritário, intermediário e minoritário, respectivamente), constituem as substâncias feromonais da espécie; as misturas ternárias e grandisal mostraram ser biologicamente ativos na atratividade de co-específicos; armadilhas colocadas a 1,50 m de altura capturaram mais espécimes em condições de campo.Abstract: The aim of this study was to isolate and identify the aggregation pheromone the papaya weevil, Pseudopiazurus obesus (Boheman, 1838), (Coleoptera: Curculionidae), in order to develop new monitoring and control methods against this pest. The study is based in three stages. The first stage was the rearing of papaya weevil; in the second stage, volatiles were obtained from males and females adults to be evaluated biological activity its in behavioral of the weevils; the third stage experiments were carried out isolation and identification of the aggregation pheromone and to evaluate the biological activity this compounds in behavioral of weevils. The main results was: male and female adults were attracted to volatiles obtained from male adults plus trunk pieces of the host plant. These results demonstrate that host plant volatiles, promote a sinergistic effect when added to male extracts; the male adults are the main responsible for the pheromone release, which starts from the 18th day after emerging; pheromone emission occurs at the scotophase, with a higher emission from 4h to 6h after the onset of the scotophase; there is no difference between pheromone emission from virgim or mated males, but there is difference among volatiles collected from males with or without food; pheromone release is affected by the food quality and decrease within time; occurring until the 105 day of life; three male-specific compounds: grandisal (main pheromone component), grandisol and papaianol are the pheromonals compounds; the ternary mixtures and grandisal show biological activity in both sexes of the papaya weevil; traps localized in 1,50 meter higher show best performance in the captures of weevils in field conditions

Graduaçăo em comunicaçăo social e tecnologia da informaçăo e comunicaçăo (TIC) : refletindo sobre o currículo /

Orientadora: Gláucia da Silva BritoDissertaçăo (mestrado) - Universidade Federal do Paraná, Setor de Educaçăo, Programa de Pós-Graduaçăo em Educaçăo. Defesa: Curitiba, 2008Inclui bibliografiaÁrea de concentraçăo: Cultura, escola e ensin