Geomorphic, sedimentary and hydraulic reconstruction of a glacial lake outburst flood in northern Alberta, Canada

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F19%3A10398710" target="_blank" >RIV/00216208:11310/19:10398710 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Wc3.hcS6in" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=Wc3.hcS6in</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1111/bor.12403" target="_blank" >10.1111/bor.12403</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Geomorphic, sedimentary and hydraulic reconstruction of a glacial lake outburst flood in northern Alberta, Canada

Popis výsledku v původním jazyce

Glacial lake outburst floods occurred frequently during the last deglaciation of the Laurentide Ice Sheet. Within the Interior Plains, these floods carved large spillway systems; however, due to a lack of abundant sediment, deposits within prairie spillways are rarely preserved. Here, we present geomorphic and sedimentary evidence and hydraulic modelling of the eastern Beaver River Spillway, formed by the catastrophic drainage of the ice-dammed glacial Lake Algar, in north central Alberta. During this flood, coarse-grained sediment eroded from local till formed large pendant bars. Within the first ~50 km of the spillway (Reach 1), pendant bars contain downstream orientated foresets overlain by horizontally bedded coarser gravels. The remaining pendant bars (Reach 2), present downflow of a moraine barrier, differ, comprising massive, matrix-supported, inversely graded gravels capped by a boulder layer. We use a HEC-GeoRAS/HEC-RAS system in conjunction with palaeostage indicators to estimate the steady-state water surface elevation. Modelling results show that peak discharge within Reach 1 of the eastern Beaver River Spillway was approximately 14 000-21 000 m3 s-1. For Reach 2, 30 km downstream, the peak discharge was estimated at 23 000-40 000 m3 s-1 (nbulked 18 000-26 000 m3 s-1). The downstream discharge increase, consistent with the sedimentary change in pendant bar deposits, is attributed to sediment bulking of the flood flow. This provides the opportunity to observe a range of flow conditions, and associated sedimentology, from a single flood event. The reconstructed flow conditions, coupled with lake volume estimates from the ponding above the moraine barrier suggest a minimum flow duration of 3-5 days.

Název v anglickém jazyce

Geomorphic, sedimentary and hydraulic reconstruction of a glacial lake outburst flood in northern Alberta, Canada

Popis výsledku anglicky

Glacial lake outburst floods occurred frequently during the last deglaciation of the Laurentide Ice Sheet. Within the Interior Plains, these floods carved large spillway systems; however, due to a lack of abundant sediment, deposits within prairie spillways are rarely preserved. Here, we present geomorphic and sedimentary evidence and hydraulic modelling of the eastern Beaver River Spillway, formed by the catastrophic drainage of the ice-dammed glacial Lake Algar, in north central Alberta. During this flood, coarse-grained sediment eroded from local till formed large pendant bars. Within the first ~50 km of the spillway (Reach 1), pendant bars contain downstream orientated foresets overlain by horizontally bedded coarser gravels. The remaining pendant bars (Reach 2), present downflow of a moraine barrier, differ, comprising massive, matrix-supported, inversely graded gravels capped by a boulder layer. We use a HEC-GeoRAS/HEC-RAS system in conjunction with palaeostage indicators to estimate the steady-state water surface elevation. Modelling results show that peak discharge within Reach 1 of the eastern Beaver River Spillway was approximately 14 000-21 000 m3 s-1. For Reach 2, 30 km downstream, the peak discharge was estimated at 23 000-40 000 m3 s-1 (nbulked 18 000-26 000 m3 s-1). The downstream discharge increase, consistent with the sedimentary change in pendant bar deposits, is attributed to sediment bulking of the flood flow. This provides the opportunity to observe a range of flow conditions, and associated sedimentology, from a single flood event. The reconstructed flow conditions, coupled with lake volume estimates from the ponding above the moraine barrier suggest a minimum flow duration of 3-5 days.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10508 - Physical geography

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Boreas

ISSN

0300-9483

e-ISSN

—

Svazek periodika

48

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

DK - Dánské království

Počet stran výsledku

13

Strana od-do

1006-1018

Kód UT WoS článku

000487900900013

EID výsledku v databázi Scopus

2-s2.0-85066507786