1,720,980 research outputs found
Supplements for Devonian–Carboniferous extension and Eurekan inversion along an inherited WNW–ESE-striking fault system in Billefjorden, Svalbard
No full textSupplementary data for Devonian–Carboniferous extension and Eurekan inversion along an inherited WNW–ESE-striking fault system in Billefjorden, Svalbard.Content:
-S1: Description of the late Paleozoic sedimentary successions in central Spitsbergen from the literature.
-S2: (a) Uninterpreted bathymetric data in Billefjorden and (b–d) associated zooms.
-S3: Interpreted seismic sections in Billefjorden showing early Cenozoic duplexes and thrusts (yellow lines), bedding surfaces (dotted white lines) and potential multiples (dashed yellow lines). See Fig. 1 for location. (a) SSW-directed Cenozoic thrust between Phantomodden and Narveneset showing (from south to north) in the southern part a well-developed SSW-verging ramp anticline and an open, symmetric, NNE-tilted detachment/ramp anticline. (b) Top-west to top-west thrust sheet with minor reverse offsets.
-S4: Uninterpreted seismic sections in Billefjorden. See S1 for location.
-S5: Description and interpretation of the upper Paleozoic sedimentary successions on seismic data in Billefjorden.
-Lower Devonian sedimentary rocks of the Siktefjellet and Red Bay and Andrée Land groups
-Uppermost Devonian to Mississippian sedimentary rocks (Billefjorden Group)
-Pennsylvanian to Permian sedimentary rocks (Gipsdalen Group)
-Uppermost Mississippian to Lower Pennsylvanian Hultberget and Ebbadalen formations
-Middle to lowermost Upper Pennsylvanian Minkinfjellet Formation
-Uppermost Middle Pennsylvanian to lowermost Permian Wordiekammen Formation
-Lower Permian Gipshuken Formation
-S6: Depth conversion data including checkshot data from exploration well 7816/12-1 in Reindalspasset (upper left table; Eide et al., 1991), the depth of lithostratigraphic intervals from the well completion report (upper right table), the depth of formations of interest to the present study from the well completion report (middle right table), average velocities of stratigraphic intervals of interest to the present study from Gernigon et al. (2018; lower right table), and calculated stratigraphic thicknesses and depths, and fault offsets in Billefjorden based on velocities from well 7816/12-1 and from Gernigon et al. (2018; lowermost table).
-S7: (a) Uninterpreted and (b) interpreted depth-converted seismic section NP-IS-85-05 through Billefjorden showing the main NNE-dipping shear zone (dashed yellow and grey-shaded), and some of the normal (red) and inverted brittle faults (black), and décollements and detachments (yellow) shown in Figure 4. Notice the gentle dip of the main shear zone. Abbreviation: GaF: Garmaksla fault.
-S8: Bathymetric profiles across NNE–SSW-trending moraine ridges (up) and a fault-related escarpment (down). Notice the contrast between smooth, 2–3 meters high drops in bathymetry across moraine ridges (black arrows) and the abrupt 5 meter drop across the fault-related escarpment (red arrow).
-S9: Bathymetric profiles across Billefjorden showing the N–S-trending ridge (red arrows). Location of the profiles is shown as white lines in supplement S1d. Notice the steep western flank and the smooth and gently east-dipping top and eastern flank of the ridge.
-S10: Satellite images in (A) Narveneset and (B) Brimerpynten (see Figure 1B for locations) showing smooth, high-frequency, gently curving, NNE–SSW- to NNW–SSE-trending lineaments (dotted white lines) most likely representing sub-vertical bedding surfaces within Lower Devonian sedimentary strata (Dallmann et al., 2004a; Dallmann & Piepjohn, 2020) crosscut by discrete, linear to undulating, dominantly WNW–ESE-trending fault-related escarpments (red lines). The legend is common to A and B.
-S11: Field photograph of WNW–ESE-striking brittle faults in Narveneset showing sinistral sense of shear.
-S12: Decreasing tectonic activity from Early Devonian to early Permian times.
-Early Devonian to Mississippian collapse and rift “initiation” phase
-Latest Mississippian to earliest/Early Pennsylvanian “interaction and linkage” phase
-Middle Pennsylvanian “through-going fault zones” phase
-Late Pennsylvanian to earliest Permian latest- to post-rift phase
-Conclusion
-Figure 1 electronic supplement 12
-S13: (A) Calculation of the surface slope angles between Pyramiden and Yggdrasilkampen and Yggdrasilkampen and Asvindalen and of the altitude difference due to the normal dip angle (c. 145 m) and to Eurekan deformation (c. 330 m). (B) Illustration of the calculated surface slope angles (in red) in Billefjorden and of the potential WNW–ESE-trending fold (in fuchsia) along the Adolfbukta fault. Notice the significant altitude drop of the base of the Wordiekammen Formation between the Pyramiden Mountain (c. 850 meters) and northern Yggdrasilkampen (c. 375 meters).
-S14: Outcrop photograph showing south-dipping and southwards thickening Lower Devonian strata of the Wood Bay Formation in Triungen in the hanging wall of the NNE-dipping Hugindalen Fault
Replication Data for: Devonian–Carboniferous extension and Eurekan inversion along an inherited WNW–ESE-striking fault system in Billefjorden, Svalbard
No full textHigh-resolution version of the figures in the following manuscript: "Devonian–Carboniferous extension and Eurekan inversion along an inherited WNW–ESE-striking fault system in Billefjorden, Svalbard". High-resolution versions of the figures are necessary to identify individual structures presented and discussed in the text
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Combining terrestrial and marine glacial archives: A geomorphological map of the Nordenskiöldbreen forefield, Svalbard
Get PDFRecent research suggests that Svalbard glaciers have retreated and thinned since the Little Ice Age. The analysis of glacial landforms and sediment deposits in the terrestrial and marine environments permits the reconstruction of the temporal and spatial variability of recent deglaciations. This study is founded on the analysis and interpretation of a geomorphological map (1:10000) of the foreland of Nordenskiöldbreen (inner Billefjorden, Svalbard). The map covers an area of ca. 43 km2 and is constructed from a combination of field observations and remotely sensed imagery from both the terrestrial and marine environments. Landforms are classified into six genetic categories: (1) subglacial, (2) ice-marginal, (3) supraglacial, (4) proglacial, (5) periglacial and (6) coastal. Glacier front positions from 1896 to present are reconstructed using historical data, oblique and vertical aerial imagery and LANDSAT and ASTER imagery. The preservation of the landform record differs between the terrestrial and marine archive. Previous studies of this region have focused on either marine or terrestrial archives and have failed to capture the complexities of the Nordenskiöldbreen forefield. As a result, pre-existing landsystem models are not applicable to Nordenskiöldbreen.
The results of this investigation suggest Nordenskiöldbreen has been a dynamic glacier with components of all Svalbard type glaciers. The retreat pattern reconstructed in this thesis indicates that water depth and bedrock pinning points (sills) played an important role in the antecedent stability of Nordenskiöldbreen. Additionally, existing landsystem models fail to capture the complexity of glaciers with a combined terrestrial and marine terminus such as Nordenskiöldbreen. The application of these models should therefore be carefully considered when investigating glaciers with a mixed terminus. This study contributes to an improved understanding of Svalbard glaciers and their response to recent climate fluctuations
Late Pleistocene-Holocene history of Svalbard ice caps and glaciers – integrating marine, terrestrial and lacustrine archives
Get PDFThe Arctic regions are affected by the modern climate change to a greater extent than the global average. This effect is called the Arctic amplification and is reflected in air temperatures rising with double rate and increased precipitation compared to the global average. The climate of Svalbard is strongly related to variations in the atmospheric and oceanic circulation patterns, and the archipelago is, therefore, ideal location to study the climate sensitivity of the Arctic.
This dissertation presents research on the Late Pleistocene and Holocene glacial history of Svalbard. Marine, lacustrine and terrestrial archives are assessed in a confined geographical area in northern Wijdefjorden, northern Spitsbergen, and the regional timing of the deglaciation, Holocene Thermal Maximum, Holocene Glacial Minimum as well as the onset of the Neoglacial are identified (Papers I-III). The research focus is on Wijdefjorden, Femmilsjøen and the NW part of the Åsgardfonna ice cap. The results are placed in a regional context and compared to studies across Svalbard. A review of the Holocene glacial history of Svalbard is presented in Paper IV, where all Holocene chronological data from Svalbard are re-calibrated or calculated and gathered in one database.
The landforms in the fjord (Paper I) and the lowermost acoustic and sedimentary facies (Papers I-II) are interpreted to be indicative of grounded, warm-based ice occupied the fjord during the Last Glacial. By contrast, Paper III speculates that parts of the terrestrial terrain are similar to forelands of cold-based glaciers in Antarctica, which may have been covered by cold-based and little erosive glacier ice during the Last Glacial.
Among the findings are that northern Svalbard deglaciated early. Wijdefjorden is inferred to deglaciate at least prior to 12.4 ± 0.3 cal. ka BP and potentially prior to 14.5 ± 0.3 cal. ka BP. Femmilsjøen deglaciated potentially prior to 16.1 ± 0.3 cal. ka BP. Deglaciation occurred in a stepwise manner and was characterised by fluctuating water temperatures and sea ice cover. Overarching, the Svalbard fjords deglaciated rapidly during the first half of the Early Holocene, however the overall retreat was punctuated by dynamic ice-advances of smaller tributary glaciers.
Femmilsjøen was isolated from the marine environment c. 11.4 cal. ka BP. The regional Holocene glacial minimum coincided with the Holocene thermal maximum (between 10.1 ± 0.4 and 3.2 ± 0.2 cal. ka BP), during which time the ice cap Åsgardfonna was small or close to absent. Collectively in Svalbard, the Holocene glacial minimum most likely occurred between 8.0 and 6.0 cal. ka BP. Thus, the Holocene thermal maximum and Holocene glacial minimum in northern Wijdefjorden seems extended compared to the rest of Svalbard. In the fjord, seawater temperatures show a gentle decrease and the sea-ice proxy a gentle increase from c. 6.0 cal. ka BP, but values do not accelerate until c. 0.5 cal. ka BP.
In Svalbard, Neoglacial glacier advances occurred generally from 4.0 to 0.5 cal. ka BP and with the Little Ice Age representing the last cold-spell of the Neoglacial. In Femmilsjøen, glacial influence recommenced from 3.2 ± 0.2 cal. ka BP, and glaciers in the catchment reached sizes no smaller than their current extent within c. 1.0 ka. The Holocene climate and glacial variability of Svalbard are strongly coupled to atmospheric and oceanic forcings
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Combining terrestrial and marine glacial archives: A geomorphological map of the Nordenskiöldbreen forefield, Svalbard
No full textRecent research suggests that Svalbard glaciers have retreated and thinned since the Little Ice Age. The analysis of glacial landforms and sediment deposits in the terrestrial and marine environments permits the reconstruction of the temporal and spatial variability of recent deglaciations. This study is founded on the analysis and interpretation of a geomorphological map (1:10000) of the foreland of Nordenskiöldbreen (inner Billefjorden, Svalbard). The map covers an area of ca. 43 km2 and is constructed from a combination of field observations and remotely sensed imagery from both the terrestrial and marine environments. Landforms are classified into six genetic categories: (1) subglacial, (2) ice-marginal, (3) supraglacial, (4) proglacial, (5) periglacial and (6) coastal. Glacier front positions from 1896 to present are reconstructed using historical data, oblique and vertical aerial imagery and LANDSAT and ASTER imagery. The preservation of the landform record differs between the terrestrial and marine archive. Previous studies of this region have focused on either marine or terrestrial archives and have failed to capture the complexities of the Nordenskiöldbreen forefield. As a result, pre-existing landsystem models are not applicable to Nordenskiöldbreen.
The results of this investigation suggest Nordenskiöldbreen has been a dynamic glacier with components of all Svalbard type glaciers. The retreat pattern reconstructed in this thesis indicates that water depth and bedrock pinning points (sills) played an important role in the antecedent stability of Nordenskiöldbreen. Additionally, existing landsystem models fail to capture the complexity of glaciers with a combined terrestrial and marine terminus such as Nordenskiöldbreen. The application of these models should therefore be carefully considered when investigating glaciers with a mixed terminus. This study contributes to an improved understanding of Svalbard glaciers and their response to recent climate fluctuations
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
