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

Røthe, Torgeir O.; Bakke, Jostein; Støren, Eivind

doi:10.1111/bor.12388

Cited by 14 publications

(21 citation statements)

References 76 publications

(127 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Boes et al, 2018;Røthe et al, 2019;Piret et al, 2021). In such settings, GLOF deposits were also represented as deposits that are finer than the background sediments (Røthe et al, 2019).…”

Section: Glacial Lake Outburst Flood Signature In Fjord Sedimentsmentioning

confidence: 99%

“…Although previous studies have investigated GLOF deposits in lake settings (e.g. Xu et al, 2015;Røthe et al, 2019), little is known about how GLOFs are recorded in fjord sediments. The only GLOF deposits that have been described in marine sediments are those of Disenchantment Bay (Alaska) (Willems et al, 2011), which are composed of stratified mud, sand and diamicton, formed by sediment gravity flows and hypopycnal plume sedimentation.…”

Section: Introductionmentioning

confidence: 99%

“…In Rundvatnet Lake in Norway, for example, GLOFs are recorded as clear sand layers embedded in a finer-grained background matrix (Xu et al, 2015). In Buarvatnet Lake (Norway), however, GLOFs are recorded as fine-grained deposits, which was explained by sediment filtration in lakes located along the course of the river (Røthe et al, 2019). Aside from intermediate lakes, which are able to trap sediments, the nature of the glacial lake dam (i.e.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Signature of modern glacial lake outburst floods in fjord sediments (Baker River, southern Chile)

et al. 2021

View full text Add to dashboard Cite

Glacial Lake Outburst Floods (GLOFs) constitute a major hazard in glacierized regions. They are particularly pronounced in the Baker River watershed (Chilean Patagonia, 48°S), where 23 events occurred between 2008 and 2020. Although GLOF deposits have previously been studied in lake settings, how modern GLOFs are recorded in fjord sediments remains mostly unknown. To address this issue, ten sediment cores collected in the fjord immediately downstream of the Baker River (Martínez Channel) were investigated and compared to the recent GLOF history of the river. Results show that sediments accumulate at 2.0 to 3.4 cm year −1 and that GLOF deposits can be distinguished from background sediments by their finer grain size (5.98 AE 0.82 μm) and lower organic carbon content (0.31 AE 0.06%), reflecting the release and transport in suspension of high amounts of glacial rock flour during GLOFs. Although 21 GLOFs from Cachet 2 Lake occurred between 2008 and 2017, the first events left a stronger imprint in the sediment, suggesting that more sediment of glacial origin was released during those initial events, possibly due to lake-bed erosion. An older GLOF deposit was tentatively linked to the outburst of Las Lengas Lake in 1988. The sediment cores also contain fine-grained turbidites, especially in the prodelta area. These turbidites confirm recent channel activity, but most of them seem to have been triggered by processes other than GLOFs. Overall, the results of this study suggest that GLOF deposits are distinct from typical flood turbidites. They are best identified by their low grain size and total organic carbon content, and best archived on the delta slope, away from any submarine channel influence. Finally, these results highlight the potential of fjord sediment archives to establish pre-historical GLOF records and ultimately improve GLOF hazard assessments.

show abstract

Section: Glacial Lake Outburst Flood Signature In Fjord Sedimentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Signature of modern glacial lake outburst floods in fjord sediments (Baker River, southern Chile)

et al. 2021

View full text Add to dashboard Cite

show abstract

“…they preferentially trap larger particles (i.e. the bedload), leaving only the finer suspended fraction of the sediment for downstream export (Gjerde et al, 2016; Røthe et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

High‐resolution fjord sediment record of a receding glacier with growing intermediate proglacial lake (Steffen Fjord, Chilean Patagonia)

Piret

Bertrand

Hawkings

et al. 2020

Earth Surf Processes Landf

View full text Add to dashboard Cite

Proglacial lakes are effective sediment traps but their impact on the reliability of downstream sediment records to reconstruct glacier variability remains unclear. Here, we investigate the sedimentary signature of the recent recession of Steffen Glacier (Chilean Patagonia, 47°S) in downstream fjord sediments, with a focus on identifying the trapping (decreased downstream sediment yield) and filtering (removal of coarse particles) effectiveness of a growing intermediate proglacial lake. Four sediment cores were collected along a 14 km longitudinal transect in Steffen Fjord and the sediment physical and chemical properties were compared with aerial imagery at high temporal resolution. The caesium‐137 (137Cs) chronology of the most distal core and sediment trap data suggest that sediment accumulation in the fjord remained relatively stable through time, despite the accelerating glacier recession and the growth of Steffen proglacial lake. This is in contrast with many studies that indicate a decrease in sediment yield during proglacial lake expansion. It implies that the increase in sediment export due to accelerating meltwater production may be balanced by the sediment trapping effect of the growing proglacial lake. The fjord sediments show a slight fining upward accompanied by a marked decrease in flood‐induced grain‐size peaks, most likely due to the increasing filtering and dampening effect of the expanding proglacial lake. Our findings show that the filtering effect of the proglacial lake reached a threshold in 1985, when the lake attained an area of 2.02 km2. The additional 5 km of glacier recession during the following 32 years did not have any significant impact on downstream sedimentation. This study confirms that proglacial lakes act as sediment traps but it indicates that (1) the trapping effect can be outpaced by accelerating glacier recession and (2) the filtering effect becomes stable once the lake attains a certain critical size. © 2020 John Wiley & Sons, Ltd.

show abstract

“…Sediments deposited in lakes have high preservation potential, and previous studies have shown how valuable lake sediment studies are to reconstruct the frequency of past natural hazards in Scandinavia, such as floods (Bøe et al, 2006; Nesje et al, 2001; Støren et al, 2010, 2016), glacier outburst floods (Røthe et al, 2019; Xu et al, 2015) and mass-wasting events (Nesje et al, 2007; Nielsen et al, 2016; Sletten et al, 2003; Vasskog et al, 2011). Recent developments in technical and analytical capacity allow us to use high-resolution x-ray computed tomography (CT) to visualise the lacustrine sediment sequence and quantify the volume of material found in the lake.…”

Section: Introductionmentioning

confidence: 99%

Wintertime extreme events recorded by lake sediments in Arctic Norway

et al. 2019

Self Cite

View full text Add to dashboard Cite

New time series of long-term hydroclimate variability in the Arctic are urgently needed in order to better understand the response patterns to external forcing and changes in boundary conditions for global climate models. Here, we present a high-resolution record of mass-wasting events based on analyses of sediments deposited in Lake Svartvatnet. Based on novel methods such as x-ray computed tomography (CT), the volume of inorganic layers in Svartvatnet is calculated and allows us to investigate the frequency of mass-wasting events during the last 9000 years in Arctic Norway. The results show an increasing activity over the late Holocene with three main phases of an increased number of mass-wasting events at 6700–5200, 4500–2800 and 1700–500 cal. yr BP. We infer that the frequency of mass-wasting events is driven by wintertime precipitation with possible links to variations in North Atlantic Oscillation (NAO) index and changes in the zonal flow regime affecting the transport of moist air masses by the westerlies over Arctic Norway. Thus, we suggest that positive NAO conditions dominated in periods with high mass-wasting activity in the mid-Holocene and late Holocene and were separated by quiescent periods at 5200–4200 and 2700–1800 cal. yr BP that represent less dominant westerlies over Arctic Norway.

show abstract

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

Cited by 14 publications

References 76 publications

Signature of modern glacial lake outburst floods in fjord sediments (Baker River, southern Chile)

Signature of modern glacial lake outburst floods in fjord sediments (Baker River, southern Chile)

High‐resolution fjord sediment record of a receding glacier with growing intermediate proglacial lake (Steffen Fjord, Chilean Patagonia)

Wintertime extreme events recorded by lake sediments in Arctic Norway

Contact Info

Product

Resources

About