The Experts below are selected from a list of 11514 Experts worldwide ranked by ideXlab platform
Carolyn H. Eyles - One of the best experts on this subject based on the ideXlab platform.
-
architectural landsystem analysis of a modern Glacial Landscape solheimajokull southern iceland
Geomorphology, 2015Co-Authors: Jessica M. Slomka, Carolyn H. EylesAbstract:Abstract Glacial terrains are commonly recorded using a landsystem approach, which allows detailed documentation of the geomorphological evolution of the Landscape. However, landsystem analysis of Quaternary subsurface stratigraphies in which landforms are not apparent or preserved is problematic, making delineation of the sedimentary architecture of a glaciated basin infill difficult. The purpose of this study is to delineate the sedimentary architecture of the Solheimajokull (southern Iceland) Glacial landsystem and to provide an architectural framework for allostratigraphy and modern analogue purposes. An integrated architectural–landsystem approach is applied here, which utilizes the principles from both architectural element analysis and landsystem analysis. A bounding surface hierarchy (fourth- to seventh-order surfaces) provides a framework within which the architecture is organized. Fieldwork was conducted at Solheimajokull glacier in 2012 and 2013; and 22 different surface features (bounded by the fourth-order surfaces) were mapped, which were grouped into four different landsystem tracts (glaciofluvial, ice-contact, jokulhlaup, and colluvial slope; bounded by the sixth-order surfaces). Landsystem tracts were deconstructed into smaller architectural units (components; bounded by the fifth-order surfaces), which allowed the delineation of eight allostratigraphic units that record the evolution of the Glacial landsystem from ~ 7000 YBP to A.D. 2013. The results of this study can provide insight to interpretation and delineation of the sedimentary architecture of other modern Glacial landsystems and subsurface Quaternary deposits in North America and other formerly glaciated areas.
-
Architectural–landsystem analysis of a modern Glacial Landscape, Sólheimajökull, southern Iceland
Geomorphology, 2015Co-Authors: Jessica M. Slomka, Carolyn H. EylesAbstract:Abstract Glacial terrains are commonly recorded using a landsystem approach, which allows detailed documentation of the geomorphological evolution of the Landscape. However, landsystem analysis of Quaternary subsurface stratigraphies in which landforms are not apparent or preserved is problematic, making delineation of the sedimentary architecture of a glaciated basin infill difficult. The purpose of this study is to delineate the sedimentary architecture of the Solheimajokull (southern Iceland) Glacial landsystem and to provide an architectural framework for allostratigraphy and modern analogue purposes. An integrated architectural–landsystem approach is applied here, which utilizes the principles from both architectural element analysis and landsystem analysis. A bounding surface hierarchy (fourth- to seventh-order surfaces) provides a framework within which the architecture is organized. Fieldwork was conducted at Solheimajokull glacier in 2012 and 2013; and 22 different surface features (bounded by the fourth-order surfaces) were mapped, which were grouped into four different landsystem tracts (glaciofluvial, ice-contact, jokulhlaup, and colluvial slope; bounded by the sixth-order surfaces). Landsystem tracts were deconstructed into smaller architectural units (components; bounded by the fifth-order surfaces), which allowed the delineation of eight allostratigraphic units that record the evolution of the Glacial landsystem from ~ 7000 YBP to A.D. 2013. The results of this study can provide insight to interpretation and delineation of the sedimentary architecture of other modern Glacial landsystems and subsurface Quaternary deposits in North America and other formerly glaciated areas.
Johan Kleman - One of the best experts on this subject based on the ideXlab platform.
-
deciphering a non Glacial Glacial Landscape mosaic in the northern swedish mountains
Geomorphology, 2008Co-Authors: Bradley W. Goodfellow, Arjen P. Stroeven, Clas Hättestrand, Johan Kleman, Krister N. JanssonAbstract:Relict surfaces contain information on past surface processes and long-term Landscape evolution. A detailed investigation of relict non-Glacial surfaces in a formerly glaciated mountain Landscape of northern Sweden was completed, based on interpretation of colour infrared aerial photographs, analysis in a GIS, and fieldwork. Working backwards from Landscape to process, surfaces were classified according to large- and small-scale morphologies that result from the operation of non-Glacial processes, the degree of weathering, regolith characteristics, and the style of Glacial modification. Surfaces were also compared in the GIS according to elevation, slope angle, and bedrock lithology. The study revealed five types of relict non-Glacial surfaces but also two types of extensively weathered Glacial surfaces that were transitional to relict non-Glacial surfaces, illustrating spatially variable processes and rates of non-Glacial and Glacial Landscape evolution. Rather than being static preGlacial remnants, relict non-Glacial surfaces are dynamic features that have continued to evolve during the Quaternary. The classification provides hypotheses for Landscape evolution that can be field tested through, for example, terrestrial cosmogenic nuclide studies and geochemical analyses of fine matrix materials. The classification may be applicable to relict non-Glacial surfaces in other formerly glaciated Landscapes.
-
Deciphering a non-Glacial/Glacial Landscape mosaic in the northern Swedish mountains
Geomorphology, 2007Co-Authors: Bradley W. Goodfellow, Arjen P. Stroeven, Clas Hättestrand, Johan Kleman, Krister N. JanssonAbstract:Relict surfaces contain information on past surface processes and long-term Landscape evolution. A detailed investigation of relict non-Glacial surfaces in a formerly glaciated mountain Landscape of northern Sweden was completed, based on interpretation of colour infrared aerial photographs, analysis in a GIS, and fieldwork. Working backwards from Landscape to process, surfaces were classified according to large- and small-scale morphologies that result from the operation of non-Glacial processes, the degree of weathering, regolith characteristics, and the style of Glacial modification. Surfaces were also compared in the GIS according to elevation, slope angle, and bedrock lithology. The study revealed five types of relict non-Glacial surfaces but also two types of extensively weathered Glacial surfaces that were transitional to relict non-Glacial surfaces, illustrating spatially variable processes and rates of non-Glacial and Glacial Landscape evolution. Rather than being static preGlacial remnants, relict non-Glacial surfaces are dynamic features that have continued to evolve during the Quaternary. The classification provides hypotheses for Landscape evolution that can be field tested through, for example, terrestrial cosmogenic nuclide studies and geochemical analyses of fine matrix materials. The classification may be applicable to relict non-Glacial surfaces in other formerly glaciated Landscapes.
-
Evidence for a relict Glacial Landscape in Quebec-Labrador
Palaeogeography Palaeoclimatology Palaeoecology, 1994Co-Authors: Johan Kleman, Ingmar Borgström, Clas HättestrandAbstract:Abstract Two major Glacial landform systems occur in Labrador. These are the radial lineation and esker swarm reflecting Late Wisconsinan decay, and the Ungava Bay lineation and esker swarm reflecting convergent northward flow. In some sectors the two landform systems give conflicting evidence regarding deglaciation pattern. We have interpreted the ice sheet dynamics in Labrador from morphological data, using a new inversion model that treats spatial patterns of deGlacial meltwater landforms separately from lineation patterns. In the George River area we have found that the Ungava Bay swarm of deGlacial landforms has been overprinted at a right angle by a younger regional meltwater pattern from the last deglaciation. A similar overprint also exists along the intersection line in west-central Labrador. These relations show that the previously accepted relative ages of the two landform systems (Hughes, 1964; Boulton and Clark, 1990a,b; Klassen and Thompson, 1993) have to be reversed. We interpret the Ungava Bay lineation and esker swarm to represent a 0.25 × 106km2 pre-Late Wisconsinan relict Landscape, formed during the deglaciation of an older ice sheet and later preserved in a dry-based central zone of the Labrador dome.
-
The Palimpsest Glacial Landscape in Northwestern Sweden: Late Weichselian deglaciation landforms and traces of older west-centered ice sheets
Geografiska Annaler: Series A Physical Geography, 1992Co-Authors: Johan KlemanAbstract:ABSTRACTThe Glacial Landscape in northwestern Sweden is a palimpsest of landforms created by several ice sheets. Using crosscutting relationships and other morphological criteria, the Glacial and glaciofluvial landforms formed during the Late Weichselian recession were discriminated and mapped separate from landforms from older Glacial events. The geographical pattern of the last deglaciation could thus be reconstructed on the basis of “young” landforms only. The Late Weichselian ice sheet was over large areas continuously cold based. Only in limited zones were thawed-bed conditions reached during the deglaciation. The older land-forms all reflect ice flow and meltwater drainage from smaller ice sheets related to the mountain chain. A marginal position, characterized by lateral moraines, of such an ice sheet was discovered along the eastern rim of the mountain chain. This marginal zone is interpreted to represent a temporary halt in the recession of an older west-centered ice sheet, possibly during isotop...
Krister N. Jansson - One of the best experts on this subject based on the ideXlab platform.
-
deciphering a non Glacial Glacial Landscape mosaic in the northern swedish mountains
Geomorphology, 2008Co-Authors: Bradley W. Goodfellow, Arjen P. Stroeven, Clas Hättestrand, Johan Kleman, Krister N. JanssonAbstract:Relict surfaces contain information on past surface processes and long-term Landscape evolution. A detailed investigation of relict non-Glacial surfaces in a formerly glaciated mountain Landscape of northern Sweden was completed, based on interpretation of colour infrared aerial photographs, analysis in a GIS, and fieldwork. Working backwards from Landscape to process, surfaces were classified according to large- and small-scale morphologies that result from the operation of non-Glacial processes, the degree of weathering, regolith characteristics, and the style of Glacial modification. Surfaces were also compared in the GIS according to elevation, slope angle, and bedrock lithology. The study revealed five types of relict non-Glacial surfaces but also two types of extensively weathered Glacial surfaces that were transitional to relict non-Glacial surfaces, illustrating spatially variable processes and rates of non-Glacial and Glacial Landscape evolution. Rather than being static preGlacial remnants, relict non-Glacial surfaces are dynamic features that have continued to evolve during the Quaternary. The classification provides hypotheses for Landscape evolution that can be field tested through, for example, terrestrial cosmogenic nuclide studies and geochemical analyses of fine matrix materials. The classification may be applicable to relict non-Glacial surfaces in other formerly glaciated Landscapes.
-
Deciphering a non-Glacial/Glacial Landscape mosaic in the northern Swedish mountains
Geomorphology, 2007Co-Authors: Bradley W. Goodfellow, Arjen P. Stroeven, Clas Hättestrand, Johan Kleman, Krister N. JanssonAbstract:Relict surfaces contain information on past surface processes and long-term Landscape evolution. A detailed investigation of relict non-Glacial surfaces in a formerly glaciated mountain Landscape of northern Sweden was completed, based on interpretation of colour infrared aerial photographs, analysis in a GIS, and fieldwork. Working backwards from Landscape to process, surfaces were classified according to large- and small-scale morphologies that result from the operation of non-Glacial processes, the degree of weathering, regolith characteristics, and the style of Glacial modification. Surfaces were also compared in the GIS according to elevation, slope angle, and bedrock lithology. The study revealed five types of relict non-Glacial surfaces but also two types of extensively weathered Glacial surfaces that were transitional to relict non-Glacial surfaces, illustrating spatially variable processes and rates of non-Glacial and Glacial Landscape evolution. Rather than being static preGlacial remnants, relict non-Glacial surfaces are dynamic features that have continued to evolve during the Quaternary. The classification provides hypotheses for Landscape evolution that can be field tested through, for example, terrestrial cosmogenic nuclide studies and geochemical analyses of fine matrix materials. The classification may be applicable to relict non-Glacial surfaces in other formerly glaciated Landscapes.
-
Time perspectives on Glacial Landscape formation - Glacial flow chronology at Lac aux Goélands, northeastern Québec, Canada
Journal of Quaternary Science, 2003Co-Authors: Anders Clarhäll, Krister N. JanssonAbstract:We used mapping from aerial photographs and field investigations around Lac Aux Goelands (Whitegull Lake), northeastern Quebec, to establish a Glacial flow chronology that involves three different Glacial landform systems. We interpret the youngest of these systems as related to the late Wisconsinan deglaciation. This system has an up-glacier discontinuity that marks a temporal shift from warm-based subGlacial conditions to non-erosive cold-based subGlacial conditions, whereby older Glacial Landscapes are preserved in the interior of Quebec–Labrador. Furthermore, our results support theories suggesting a northward migrating ice divide to a final position south of Ungava Bay during the final deglaciation. The recognition that a Glacial Landscape is fragmented and consists of smaller, temporally unrelated units is of considerable significance in understanding ice-sheet dynamics and patterns of subGlacial preservation and destruction. This is because a fragmented Landscape implies a fragmented formation history, where formation of subGlacial landforms occurred in restricted subGlacial zones during restricted time periods. Periods of formation must have been separated by periods of preservation and inhibited subGlacial reshaping. Based on estimates of the ice margin retreat velocity and the velocity of the warm-based inward migrating zone, we suggest that periods of preservation were orders of magnitude longer than periods of subGlacial landform formation. Copyright © 2003 John Wiley & Sons, Ltd.
Jessica M. Slomka - One of the best experts on this subject based on the ideXlab platform.
-
architectural landsystem analysis of a modern Glacial Landscape solheimajokull southern iceland
Geomorphology, 2015Co-Authors: Jessica M. Slomka, Carolyn H. EylesAbstract:Abstract Glacial terrains are commonly recorded using a landsystem approach, which allows detailed documentation of the geomorphological evolution of the Landscape. However, landsystem analysis of Quaternary subsurface stratigraphies in which landforms are not apparent or preserved is problematic, making delineation of the sedimentary architecture of a glaciated basin infill difficult. The purpose of this study is to delineate the sedimentary architecture of the Solheimajokull (southern Iceland) Glacial landsystem and to provide an architectural framework for allostratigraphy and modern analogue purposes. An integrated architectural–landsystem approach is applied here, which utilizes the principles from both architectural element analysis and landsystem analysis. A bounding surface hierarchy (fourth- to seventh-order surfaces) provides a framework within which the architecture is organized. Fieldwork was conducted at Solheimajokull glacier in 2012 and 2013; and 22 different surface features (bounded by the fourth-order surfaces) were mapped, which were grouped into four different landsystem tracts (glaciofluvial, ice-contact, jokulhlaup, and colluvial slope; bounded by the sixth-order surfaces). Landsystem tracts were deconstructed into smaller architectural units (components; bounded by the fifth-order surfaces), which allowed the delineation of eight allostratigraphic units that record the evolution of the Glacial landsystem from ~ 7000 YBP to A.D. 2013. The results of this study can provide insight to interpretation and delineation of the sedimentary architecture of other modern Glacial landsystems and subsurface Quaternary deposits in North America and other formerly glaciated areas.
-
Architectural–landsystem analysis of a modern Glacial Landscape, Sólheimajökull, southern Iceland
Geomorphology, 2015Co-Authors: Jessica M. Slomka, Carolyn H. EylesAbstract:Abstract Glacial terrains are commonly recorded using a landsystem approach, which allows detailed documentation of the geomorphological evolution of the Landscape. However, landsystem analysis of Quaternary subsurface stratigraphies in which landforms are not apparent or preserved is problematic, making delineation of the sedimentary architecture of a glaciated basin infill difficult. The purpose of this study is to delineate the sedimentary architecture of the Solheimajokull (southern Iceland) Glacial landsystem and to provide an architectural framework for allostratigraphy and modern analogue purposes. An integrated architectural–landsystem approach is applied here, which utilizes the principles from both architectural element analysis and landsystem analysis. A bounding surface hierarchy (fourth- to seventh-order surfaces) provides a framework within which the architecture is organized. Fieldwork was conducted at Solheimajokull glacier in 2012 and 2013; and 22 different surface features (bounded by the fourth-order surfaces) were mapped, which were grouped into four different landsystem tracts (glaciofluvial, ice-contact, jokulhlaup, and colluvial slope; bounded by the sixth-order surfaces). Landsystem tracts were deconstructed into smaller architectural units (components; bounded by the fifth-order surfaces), which allowed the delineation of eight allostratigraphic units that record the evolution of the Glacial landsystem from ~ 7000 YBP to A.D. 2013. The results of this study can provide insight to interpretation and delineation of the sedimentary architecture of other modern Glacial landsystems and subsurface Quaternary deposits in North America and other formerly glaciated areas.
Andrew J. Russell - One of the best experts on this subject based on the ideXlab platform.
-
A multi-dimensional analysis of pro-Glacial Landscape change at Sólheimajökull, southern Iceland
Earth Surface Processes and Landforms, 2014Co-Authors: Kate E. H. Staines, Andrew J. Russell, Jonathan L. Carrivick, Fiona S. Tweed, Andrew J. Evans, Tómas Jóhannesson, Matthew J. RobertsAbstract:ProGlacial Landscapes are some of the most active on Earth. Previous studies of proGlacial Landscape change have often been restricted to considering either sedimentological, geomorphological or topographic parameters in isolation and are often mono-dimensional. This study utilised field surveys and digital elevation model analyses to quantify planform, elevation and volumetric proGlacial Landscape change at Solheimajokull in southern Iceland for multiple time periods spanning from 1960 to 2010. As expected, the most intense geomorphological changes persistently occurred in the ice-proximal area. During 1960 to 1996 the proGlacial river was relatively stable. However, after 2001 braiding intensity was higher, channel slope shallower and there was a shift from overall incision to aggradation. Attributing these proGlacial river channel changes to the 1999 jokulhlaup is ambiguous because it coincided with a switch from a period of glacier advance to that of glacier retreat. Furthermore, glacier retreat (of ~ 40 m.yr-1) coincided with ice-marginal lake development and these two factors have both altered the proGlacial river channel head elevation. From 2001 to 2010 progressive increase in channel braiding and progressive downstream incision occurred; these together probably reflecting stream power due to increased glacier ablation and reduced sediment supply due to trapping of sediment by the developing ice-marginal lake. Overall, this study highlights rapid spatiotemporal proGlacial Landscape reactions to changes in Glacial meltwater runoff regimes, glacier terminus position, sediment supply and episodic events such as jokuhlaups. Recognising the interplay of these controlling factors on proGlacial Landscapes will be important for understanding the geological record and for Landscape stability assessments.
-
Hydrogeological implications of Glacial Landscape evolution at Skeiðarársandur, SE Iceland
Geomorphology, 2007Co-Authors: Zoe P. Robinson, Ian J. Fairchild, Andrew J. RussellAbstract:Abstract Patterns of groundwater recharge and flow in present day and palaeo-Glacial environments are governed by both geomorphology and subsurface sedimentology. This paper assesses the hydrogeological implications of Glacial Landscape evolution and develops a conceptual model of Glacial Landscape evolution and hydrogeological interaction. The ice-marginal zone of Skeiðararsandur, SE Iceland was selected as a case study of a temperate, actively-receding glacier landsystem that is affected by both surging behaviour and periodic glacier outburst floods (jokulhlaups). The groundwater table elevation was measured approximately every 2–5 days throughout two six-week summer field seasons in 2000 and 2001, and once in March 2001, using a network of shallow piezometers, and hydraulic conductivity was calculated based on grain-size distribution analysis of sampled aquifer materials. The hydraulic conductivity of the near surface aquifer at the study site spans three orders of magnitude and is highest and most varied in areas inundated by the November 1996 jokulhlaup. The shallow water table in the study area responds dynamically to precipitation events with the greatest fluctuation in an enclosed moraine lake basin with a perched aquifer underlain by ice and in a zone of outwash fans proximal to the ice margin. The seasonal decline in water table is greatest at the ice margin, reflecting the reduced winter recharge from the stagnant ice zone. Landsystems with morainic relief are associated with localised moraine/precipitation-fed groundwater systems. These localised groundwater systems are superimposed on the intermediate/regional scale groundwater systems that discharge further down sandur and offshore and are dominated by the gently-sloping geomorphologically-uniform outwash plain. Groundwater-fed lakes, formed in depressions from ice blocks deposited during jokulhlaups, may provide important ecological niches. The investigations at this site demonstrate that Glacial outburst floods and glacier margin fluctuations produce a suite of sediments, landforms and environments that affect the hydrogeological system.