Megafloods and Clovis cache at Wenatchee, Washington

2016 ◽  
Vol 85 (3) ◽  
pp. 430-444 ◽  
Author(s):  
Richard B. Waitt
Keyword(s):  
British Columbia ◽  
Glacial Lake ◽  
Outburst Flood ◽  
Grand Coulee

Immense late Wisconsin floods from glacial Lake Missoula drowned the Wenatchee reach of Washington's Columbia valley by different routes. The earliest debacles, nearly 19,000 cal yr BP, raged 335 m deep down the Columbia and built high Pangborn bar at Wenatchee. As advancing ice blocked the northwest of Columbia valley, several giant floods descended Moses Coulee and backflooded up the Columbia past Wenatchee. Ice then blocked Moses Coulee, and Grand Coulee to Quincy basin became the westmost floodway. From Quincy basin many Missoula floods backflowed 50 km upvalley to Wenatchee 18,000 to 15,500 years ago. Receding ice dammed glacial Lake Columbia centuries more—till it burst about 15,000 years ago. After Glacier Peak ashfall about 13,600 years ago, smaller great flood(s) swept down the Columbia from glacial Lake Kootenay in British Columbia. The East Wenatchee cache of huge fluted Clovis points had been laid atop Pangborn bar after the Glacier Peak ashfall, then buried by loess. Clovis people came five and a half millennia after the early gigantic Missoula floods, two and a half millennia after the last small Missoula flood, and two millennia after the glacial Lake Columbia flood. People likely saw outburst flood(s) from glacial Lake Kootenay.

Professor Mathews, outburst floods, and other glaciological disasters

1986 ◽  
Vol 23 (6) ◽  
pp. 859-868 ◽  
Author(s):  
Garry K. C. Clarke
Keyword(s):  
British Columbia ◽  
Physical Model ◽  
Mining Operation ◽  
Glacial Lake ◽  
Outburst Flood ◽  
Transportation Corridor ◽  
Outburst Floods ◽  
Flood Magnitude ◽  
Unusual Problem

Misfortunes befalling the Granduc mining operation near Stewart, British Columbia, stimulated Professor Mathews' influential scientific contributions on subglacial hydrology. A series of violent floods from glacier-dammed Summit Lake menaced the transportation corridor between the Granduc ore concentrator and a tidewater dock at Hyder, Alaska. This unusual problem motivated the research of Mathews and later of Gilbert, who together laid the foundation for a greater understanding of the physics of outburst floods. The physical model that evolved from their research can be used to predict outburst flood magnitude and to cast light on the hydrology of ancient floods such as those from glacial Lake Missoula.

Sustained Impact of a Glacial Lake Outburst Flood on Winter Turbidity Regimes across the Land-Ocean Aquatic Continuum

2021 ◽  
Author(s):  
Ian Giesbrecht ◽  
Suzanne Tank ◽  
Justin Del Bel Belluz ◽  
Jennifer Jackson
Keyword(s):  
Freshwater Ecosystems ◽  
Glacial Lake ◽  
Mass Wasting ◽  
Outburst Flood ◽  
Fisheries Resources ◽  
Carbon Burial ◽  
Source To Sink ◽  
Creek Watershed ◽  
Glacial Lake Outburst Flood ◽  
The Impact

<p>Rainforest rivers export large quantities of terrestrial materials from watersheds to the coastal ocean, with important implications for local ecosystems and global biogeochemical cycles. However, the impact of episodic disturbance on this process is a critical knowledge gap in our understanding of land-sea connections. Fjords represent a global hotspot for terrestrial carbon burial in marine sediments, yet the relative importance of typical riverine fluxes vs. mass wasting fluxes is uncertain and dynamic. Similarly, mass wasting events can generate both an instantaneous pulse and a sustained shift in the material export regime. Riverine sediment regimes also have important implications for freshwater ecosystems and fisheries resources. A recent mass wasting event in Bute Inlet – Homalco First Nation traditional territory and British Columbia, Canada – presents an important opportunity to quantify the sustained impact of such an infrequent large disturbance on the source-to-sink linkages between glacierized mountains, rivers, and fjords.</p><p>On November 28, 2020, a landslide in the headwaters of the Elliot Creek watershed (118 km<sup>2</sup>) triggered a glacial lake outburst flood (GLOF) that eroded 3 km<sup>2</sup> of forested land and exported large volumes of water and terrestrial materials to the lower reaches of the Southgate River watershed (1986 km<sup>2</sup>) and ultimately to the head of Bute Inlet. Here we assess river and ocean surface turbidity over four winter months following the event, in comparison to pre-event measurements taken across all seasons in recent years. River turbidity was measured on the Southgate River above and below the confluence of Elliot Creek, beginning in December 2020, and at the mouth of the Southgate and nearby Homathko Rivers prior to November 2020. Bute Inlet turbidity was measured (every month to two months) starting in May 2017.</p><p>Prior to the GLOF event, Southgate River turbidity ranged from a low of 3.3 ± 0.4 FNU in the winter to a high of 71.4 FNU in the summer meltwater period. Since the event, Southgate River turbidity has been consistently elevated ≥6 times background levels recorded above Elliot Creek. At the extreme, on January 13, 2021, seven weeks after the GLOF, Southgate River mean turbidity (105.2 ± 3.3 FNU) was 32 times the background (3.3 ± 0.4 FNU), equating to a sustained increase in wintertime turbidity that sometimes exceeds the historical summertime peak. Given the typical coupling of turbidity with discharge, we expect further increases in turbidity with the coming freshet of 2021; the first meltwater season following the GLOF. These results suggest the potential for a sustained shift in the seasonal turbidity regime of the Southgate River and the estuarine waters of Bute Inlet. The elevated turbidity signals broader changes to: sediment export and carbon burial, the depth and seasonality of light penetration, river water quality, and spawning habitat quality for anadromous fish. Ongoing monitoring will be used to characterize the duration, dynamics, and potential recovery of elevated turbidity regimes across the land-to-ocean aquatic continuum in Bute Inlet.</p>

scholarly journals Identification of Locations for Potential Glacial Lakes Formation using Remote Sensing Technology

2013 ◽  
Vol 12 ◽  
pp. 10-16
Author(s):  
P Yagol ◽  
A Manandhar ◽  
P Ghimire ◽  
RB Kayastha ◽  
JR Joshi
Keyword(s):  
Remote Sensing ◽  
Glacial Lake ◽  
Glacial Lakes ◽  
Outburst Flood ◽  
Remote Sensing Technology ◽  
Sensing Technology ◽  
Lake Formation ◽  
Significant Area ◽  
Glacial Lake Outburst Flood

In past Nepal has encountered a number of glacial lake outburst flood (GLOF) events causing loss of billions of rupees. Still there are a number of glacial lakes forming and there are chances of new glacial lake formation. Hence there is intense need to monitor glaciers and glacial lakes. The development on remote sensing technology has eased the researches on glacier and glacial lakes. Identification of locations of potential glacial lakes through the use of remote sensing technology has been proven and hence is opted for identification of locations of potential glacial lake in Khumbu Valley of Sagarmatha Zone, Nepal. The probable sites for glacial lake formation are at Ngojumpa, Lobuche, Khumbu, Bhotekoshi, Inkhu, Kyasar, Lumsumna, etc. As per study, the biggest glacial lake could form at Ngozumpa glacier. Even in other glaciers potential supra-glacial lakes could merge together to form lakes that occupy significant area. Nepalese Journal on Geoinformatics -12, 2070 (2013AD): 10-16

scholarly journals The 2020 glacial lake outburst flood at Jinwuco, Tibet: causes, impacts, and implications for hazard and risk assessment

2021 ◽  
Author(s):  
Guoxiong Zheng ◽  
Martin Mergili ◽  
Adam Emmer ◽  
Simon Allen ◽  
Anming Bao ◽  
...  
Keyword(s):  
Time Lag ◽  
Peak Discharge ◽  
Glacial Lake ◽  
Lateral Moraine ◽  
Process Chain ◽  
Outburst Flood ◽  
Impact Wave ◽  
Debris Landslide ◽  
Property Losses ◽  
Glacial Lake Outburst Flood

Abstract. We analyze and reconstruct a recent Glacial Lake Outburst Flood (GLOF) process chain on 26 June 2020, involving the moraine-dammed proglacial lake Jinwuco (30.356° N, 93.631° E) in eastern Nyainqentanglha, Tibet, China. Satellite images reveal that from 1965 to 2020, the surface area of Jinwuco has expanded by 0.2 km2 (+56 %) to 0.56 km2, and subsequently decreased to 0.26 km2 (‒54 %) after the GLOF. Estimates based on topographic reconstruction and sets of published empirical relationships indicate that the GLOF had a volume of 10 million m3, an average breach time of 0.62 hours, and an average peak discharge of 5,390 m3/s at the dam. Based on pre- and post-event high-resolution satellite scenes, we identified a large progressive debris landslide originating from western lateral moraine, having occurred 5–17 days before the GLOF. This landslide was most likely triggered by extremely heavy, south Asian monsoon-associated rainfall in June. The time lag between the landslide and the GLOF suggests that pre-weakening of the dam due to landslide-induced outflow pushed the system towards a tipping point, that was finally exceeded following subsequent rainfall, snowmelt, a secondary landslide, or calving of ice into the lake. We back-calculate part of the GLOF process chain, using the GIS-based open source numerical simulation tool r.avaflow. Two scenarios are considered, assuming a debris landslide-induced impact wave with overtopping and resulting retrogressive erosion of the moraine dam (Scenario A), and retrogressive erosion due to pre-weakening of the dam without a major impact wave (Scenario B). Both scenarios yield plausible results which are in line with empirically derived ranges of peak discharge and breach time. The breaching process is characterized by a slower onset and a resulting delay in Scenario B, compared to Scenario A. Evidence, however, points towards Scenario B as a more realistic possibility. There were no casualties from this GLOF but it caused severe destruction of infrastructure (e.g. roads and bridges) and property losses in downstream areas. Given the clear role of continued glacial retreat in destabilizing the adjacent lateral moraine slopes, and directly enabling the landslide to deposit into the expanding lake body, the GLOF process chain under Scenario B can be robustly attributable to anthropogenic climate change, while downstream consequences have been enhanced by the development of infrastructure on exposed flood plains. Such process chains could become more frequent under a warmer and wetter future climate, calling for comprehensive and forward-looking risk reduction planning.

Glacier recession and glacial lake outburst flood studies in Zanskar basin, western Himalaya

2018 ◽  
Vol 564 ◽  
pp. 376-396 ◽  
Author(s):  
Riyaz Ahmad Mir ◽  
Sanjay K. Jain ◽  
A.K. Lohani ◽  
Arun K. Saraf
Keyword(s):  
Western Himalaya ◽  
Glacial Lake ◽  
Outburst Flood ◽  
Glacier Recession ◽  
Glacial Lake Outburst Flood

A landslide-generated tsunami and outburst flood at Elliot Creek, coastal British Columbia  

2021 ◽  
Author(s):  
Marten Geertsema ◽  
Brian Menounos ◽  
Dan Shugar ◽  
Tom Millard ◽  
Brent Ward ◽  
...  
Keyword(s):  
British Columbia ◽  
Rock Avalanche ◽  
Lake Basin ◽  
Outburst Flood ◽  
Coast Mountains ◽  
Rock Face ◽  
Valley Fill ◽  
Causative Relationship ◽  
Displacement Wave ◽  
Steep Slopes

<p>On 28 November 2020, about 18 Mm<sup>3</sup> of quartz diorite detached from a steep rock face at the head of Elliot Creek in the southern Coast Mountains of British Columbia. The rock mass fragmented as it descended 1000 m and flowed across a debris-covered glacier. The rock avalanche was recorded on local and distant seismometers, with long-period amplitudes equivalent to a M 4.9 earthquake. Local seismic stations detected several earthquakes of magnitude <2.4 over the minutes and hours preceding the slide, though no causative relationship is yet suggested. More than half of the rock debris entered a 0.6 km<sup>2 </sup>lake, where it generated a huge displacement wave that overtopped the moraine at the far end of the lake. Water that left the lake was channelized along Elliot Creek, deeply scouring the valley fill over a distance of 10 km before depositing debris on a 2 km<sup>2</sup> fan in the Southgate River valley. Debris temporarily dammed the river, and turbid water continued down the Southgate River to Bute Inlet, where it produced a 70 km turbidity current and altered turbidity and water chemistry in the inlet for weeks. The landslide followed a century of rapid glacier retreat and thinning that exposed a growing lake basin. The outburst flood extended the damage of the landslide far beyond the limit of the landslide, destroying forest and impacting salmon spawning and rearing habitat. We expect more cascading impacts from landslides in the glacierized mountains of British Columbia as glaciers continue to retreat, exposing water bodies below steep slopes while simultaneously removing buttressing support.</p>

Status of Glacial Lake Columbia during the Last Floods from Glacial Lake Missoula

1987 ◽  
Vol 27 (2) ◽  
pp. 182-201 ◽  
Author(s):  
Brian F. Atwater
Keyword(s):  
Columbia River ◽  
River Valley ◽  
Glacial Lake ◽  
Grand Coulee

AbstractThe last floods from glacial Lake Missoula, Montana, probably ran into glacial Lake Columbia, in northeastern Washington. In or near Lake Columbia's Sanpoil arm, Lake Missoula floods dating from late in the Fraser glaciation produced normally graded silt beds that become thinner upsection and which alternate with intervals of progressively fewer varves. The highest three interflood intervals each contain only one or two varves, and about 200–400 successive varves conformably overlie the highest flood bed. This sequence suggests that jökulhlaup frequency progressively increased until Lake Missoula ended, and that Lake Columbia outlasted Lake Missoula. The upper Grand Coulee, Lake Columbia's late Fraser-age outlet, contains a section of 13 graded beds, most of them sandy and separated by varves, that may correlate with the highest Missoula-flood beds of the Sanpoil River valley. The upper Grand Coulee also contains probable correlatives of many of the approximately 200–400 succeeding varves, as do nearby parts of the Columbia River valley. This collective evidence casts doubt on a prevailing hypothesis according to which one or more late Fraser-age floods from Lake Missoula descended the Columbia River valley with little or no interference from Lake Columbia's Okanogan-lobe dam.

scholarly journals Hydraulic Reconstruction of the 1818 Giétro Glacial Lake Outburst Flood

2019 ◽  
Vol 55 (11) ◽  
pp. 8840-8863 ◽  
Author(s):  
C. Ancey ◽  
E. Bardou ◽  
M. Funk ◽  
M. Huss ◽  
M. A. Werder ◽  
...  
Keyword(s):  
Glacial Lake ◽  
Outburst Flood ◽  
Glacial Lake Outburst Flood

Late Quaternary geology and geomorphology of the Elk Valley, southeastern British Columbia

1987 ◽  
Vol 24 (4) ◽  
pp. 741-751 ◽  
Author(s):  
H. George ◽  
W. A. Gorman ◽  
D. F. VanDine
Keyword(s):  
British Columbia ◽  
Late Quaternary ◽  
Rocky Mountain ◽  
Quaternary Geology ◽  
Glacial Lake ◽  
Three Stages ◽  
Late Wisconsinan ◽  
Two Stages

Glacial stratigraphy and geomorphology of the bottom areas of the Elk Valley support the existence of one major ice advance, presumably during the late Wisconsinan. Its retreat probably occurred in two stages by orderly frontal withdrawal. Glacial Lake Elk, formed within the Elk Valley from meltwaters released by this glacier, was dammed initially by an ice plug from the Rocky Mountain Trench glacier at a point near Morrissey and subsequently less than 3 km upvalley from Elko. The lake drained in at least three stages.

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