Controls on the formation and sudden drainage of glacier-impounded lakes: implications for jökulhlaup characteristics

Tweed, Fiona S.; Russell, Andrew J.

doi:10.1177/030913339902300104

Cited by 163 publications

(83 citation statements)

References 116 publications

(42 reference statements)

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“…The resulting sequences therefore cannot be considered to form part of cycles (cf. Björnsson 1992Björnsson , 1998Tweed & Russell 1999).…”

Section: A Model Of the Sequences And Cyclesmentioning

confidence: 99%

Pleistocene sandur deposits represent braidplains, not alluvial fans

Zieliński¹,

Loon²

2003

Boreas

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2003 (December): Pleistocene sandur deposits represent braidplains, not alluvial fans. Boreas, Vol. 32, pp. 590-611. Oslo. ISSN 0300-9483.Weichselian sandar in NE Poland show characteristics that are inconsistent with the commonly accepted alluvialfan-like model for outwash deposition and sandur formation. Analysis of the lithofacies and their vertical and lateral transitions indicates that the Polish sandar developed as braidplains, not as alluvial fans. Analysis of the geomorphic conditions under which modern sandar form, indicates that these conditions (which are characterized by deposition in a narrow belt between ice-covered mountain ranges and the sea) cannot be considered representative of those that prevailed in the geological past when sandar developed as braidplains in confined valleys, to end up in a lowland area where the deposits could spread out further in lateral directions. The latter conditions have been found consistently for all Polish Weichselian sandar that were investigated in much sedimentological detail. This raises the question whether sandar are alluvial fans or not. Because the development of the sandar in NE Poland seems to be much more representative for outwash deposition than the present-day sandar in Iceland and elsewhere, the current alluvial-fan-like sandur model -based on the fairly exceptional present-day situation with deposition in a narrow belt -should therefore be replaced by the braidplain-like sandur model -based on deposition in a valley and in a wider lowland area in front -that has been established for the Polish examples.

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“…The resulting sequences therefore cannot be considered to form part of cycles (cf. Björnsson 1992Björnsson , 1998Tweed & Russell 1999).…”

Section: A Model Of the Sequences And Cyclesmentioning

confidence: 99%

Pleistocene sandur deposits represent braidplains, not alluvial fans

Zieliński¹,

Loon²

2003

Boreas

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“…E-mail: mipeal@utu.fi Extreme hydrological events, such as glacial outburst floods (jökulhlaups) have not been predicted using hydraulic modelling and geoinformatics combined. Compared to regular rain-related river floods, glacial outburst floods have particular characteristics, including a highly peaked hydrograph shape related to the triggering mechanism of the flood and its total volume (Björnsson, 1975;Tweed and Russell, 1999;Björnsson, 2002). Glacial outburst flood characteristics are linked to the controls of the ice-dammed or glacier-impounded lake drainage (Tweed and Russell, 1999).…”

Section: Introductionmentioning

confidence: 99%

“…Compared to regular rain-related river floods, glacial outburst floods have particular characteristics, including a highly peaked hydrograph shape related to the triggering mechanism of the flood and its total volume (Björnsson, 1975;Tweed and Russell, 1999;Björnsson, 2002). Glacial outburst flood characteristics are linked to the controls of the ice-dammed or glacier-impounded lake drainage (Tweed and Russell, 1999). Glacier-impounded lake formation and location are strongly related to glacier fluctuation and topographical settings.…”

Section: Introductionmentioning

confidence: 99%

Comparing a 1D hydraulic model with a 2D hydraulic model for the simulation of extreme glacial outburst floods

Alho

Aaltonen

2007

Hydrological Processes

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Abstract:Glacial outburst floods (jökulhlaups) destroy a significant amount of infrastructure in proglacial areas. Nevertheless, few studies have simulated extreme jökulhlaup inundation using hydraulic modelling. In this study, we demonstrate the capability of one-dimensional jökulhlaup simulation (HEC-RAS modelling software) and compare simulation results with those from a two-dimensional finite element model (TELEMAC-2D modelling software) to determine the potential and limitations of one-dimensional modelling for jökulhlaup simulations. In both models, a pre-defined hydrograph was used as an upstream boundary condition for the jökulhlaup, which was simulated on the Möðrudalur floodplain, northeast Iceland. An unsteady flow simulation of the rising stage of the flood (5 h 15 min) was undertaken with both models to produce maps of flood inundation and flow depth. The study shows that simulations had a 200 m horizontal difference in inundated area at the peak discharge stage. Additional differences were also detected in the rising stage of the hydrograph. The most significant differences between the models was found at the time when the front of the jökulhlaup inundated a new area through a sinuous gorge, or when inundation took place through a complex flow route (maximum difference ¾1800 m). This study demonstrates that one-dimensional modelling of jökulhlaup propagation provides results broadly comparable to data derived from more complex simulations.

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“…The newly exposed de-glaciated landscapes in the vicinity of the glaciers may lead to the formation of unstable lakes (Carrivick & Tweed 2013). The formation of glacier-dammed lakes may occur supraglacially, subglacially or along the ice margin (Walder & Fountain 1997;Tweed & Russell 1999). These lakes may develop into hazards when a critical threshold for lake drainage is reached, and consequently, a sudden release of the icedammed water causes a glacier outburst flood (GLOF; Paterson 1994;Tweed & Russell 1999).…”

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confidence: 99%

Glacier outburst floods reconstructed from lake sediments and their implications for Holocene variations of the plateau glacier Folgefonna in western Norway

Røthe

Bakke

Støren

2019

Boreas

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A sudden release of large volumes of water during a glacier outburst flood (GLOF) is a major hazard worldwide. Here, we identify the sedimentary signature of glacial and non‐glacial processes, including GLOFs, based on lacustrine sediments from the distal glacier‐fed Lake Buarvatnet in western Norway. Historically documented GLOFs in 2002 CE and during the 1980s CE are identified in the 210Pb‐ and 14C‐dated sediments. These events have the same sedimentary signature as 12 earlier events throughout the Holocene interpreted to represent previous GLOFs in the catchment. The GLOFs are interpreted to have occurred during periods when the glacier extent was similar to the modern positions, and the events are thus used to pinpoint past positions of the glacier terminus and, hence, the equilibrium line altitudes (ELAs). The results indicate that the glacier Svartenutbreen, located at the eastern part of Folgefonna, had a similar size in 2002 CE as c. 8200–8300 cal. a BP, corresponding to the 8.2 ka event in the North Atlantic region. The regrowth of Sørfonna after the Holocene Thermal Optimum occurred at c. 6900 cal. a BP and Svartenutbreen was at modern size and extent in the periods c. 6400, c. 5450, c. 4850, c. 3850, c. 3550 and c. 1650 cal. a BP. Since 1650 cal. a BP, we infer that the glacier was larger than the 2002 CE glacier extent until 1910 CE when a GLOF occurred. Svartenutbreen has been retreating since 1910 CE, which led to the ice damming of the two historical GLOFs in the 1980s and 2002 CE separated by a glacier advance in the 1990s CE. The findings are discussed and compared to other regional glacier reconstructions in Norway, and emphasize the value of identifying and utilizing GLOFs as an indicator of past ELA variability.

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Controls on the formation and sudden drainage of glacier-impounded lakes: implications for jökulhlaup characteristics

Cited by 163 publications

References 116 publications

Pleistocene sandur deposits represent braidplains, not alluvial fans

Pleistocene sandur deposits represent braidplains, not alluvial fans

Comparing a 1D hydraulic model with a 2D hydraulic model for the simulation of extreme glacial outburst floods

Glacier outburst floods reconstructed from lake sediments and their implications for Holocene variations of the plateau glacier Folgefonna in western Norway

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