Equifinality and preservation potential of complex eskers

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F19%3A10399503" target="_blank" >RIV/00216208:11310/19:10399503 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=bC1JAc26t7" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=bC1JAc26t7</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1111/bor.12414" target="_blank" >10.1111/bor.12414</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Equifinality and preservation potential of complex eskers

Popis výsledku v původním jazyce

Eskers are useful for reconstructing meltwater drainage systems of glaciers and ice sheets. However, our process understanding of eskers suffers from a disconnect between sporadic detailed morpho-sedimentary investigations of abundant large-scale ancient esker systems, and a small numberof modern analogueswhere esker formation has been observed. This paper presents the results of detailed field and high-resolution remote sensing studies into two esker systems that have recently emerged at Horbyebreen, Svalbard, and one at BreiðamerkurjEURokull, Iceland. Despite the different glaciological settings (polythermal valleyglacier vs. active temperate piedmont lobe), in all cases a distinctive planform morphology has developed, where ridges are orientated in two dominant directions corresponding to the direction of ice flowand the shape of the ice margin. These two orientations in combination forma cross-cutting and locally rectilinear pattern. One set of ridges atHorbyebreen is a hybrid of eskers and geometric ridges formed during a surge and/or jEURokulhlaup event. The other sets of ridges are eskers formed time-transgressively at a retreating ice margin. The similar morphology of esker complexes formed in different ways on both glacier forelands implies equifinality, meaning that care should be taken when interpreting Quaternary esker patterns. The eskers at Horbyebreen contain substantial ice-cores with a high ice:sediment ratio, suggesting that they would be unlikely to survive after ice melt.TheBreiðamerkurjEURokull eskers emerged fromterrain characterized byburied ice that has melted out. Our observations lead us to conclude that eskers may reflect a wide range of processes at dynamic ice margins, including significantparaglacial adjustments. Thiswork, aswell as previous studies, confirmsthat constraintsonesker morphology include: topographic setting (e.g. confined valley or broad plain); sediment and meltwater availability (including surges and jEURokulhlaups); position of formation (supraglacial, englacial or subglacial); and ice-marginal dynamics such as channel abandonment, the formation ofoutwash heads or theburial and/or exhumation of dead ice.

Název v anglickém jazyce

Equifinality and preservation potential of complex eskers

Popis výsledku anglicky

Eskers are useful for reconstructing meltwater drainage systems of glaciers and ice sheets. However, our process understanding of eskers suffers from a disconnect between sporadic detailed morpho-sedimentary investigations of abundant large-scale ancient esker systems, and a small numberof modern analogueswhere esker formation has been observed. This paper presents the results of detailed field and high-resolution remote sensing studies into two esker systems that have recently emerged at Horbyebreen, Svalbard, and one at BreiðamerkurjEURokull, Iceland. Despite the different glaciological settings (polythermal valleyglacier vs. active temperate piedmont lobe), in all cases a distinctive planform morphology has developed, where ridges are orientated in two dominant directions corresponding to the direction of ice flowand the shape of the ice margin. These two orientations in combination forma cross-cutting and locally rectilinear pattern. One set of ridges atHorbyebreen is a hybrid of eskers and geometric ridges formed during a surge and/or jEURokulhlaup event. The other sets of ridges are eskers formed time-transgressively at a retreating ice margin. The similar morphology of esker complexes formed in different ways on both glacier forelands implies equifinality, meaning that care should be taken when interpreting Quaternary esker patterns. The eskers at Horbyebreen contain substantial ice-cores with a high ice:sediment ratio, suggesting that they would be unlikely to survive after ice melt.TheBreiðamerkurjEURokull eskers emerged fromterrain characterized byburied ice that has melted out. Our observations lead us to conclude that eskers may reflect a wide range of processes at dynamic ice margins, including significantparaglacial adjustments. Thiswork, aswell as previous studies, confirmsthat constraintsonesker morphology include: topographic setting (e.g. confined valley or broad plain); sediment and meltwater availability (including surges and jEURokulhlaups); position of formation (supraglacial, englacial or subglacial); and ice-marginal dynamics such as channel abandonment, the formation ofoutwash heads or theburial and/or exhumation of dead ice.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10508 - Physical geography

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach<br>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

2020

Číslo periodika v rámci svazku

January

Stát vydavatele periodika

DK - Dánské království

Počet stran výsledku

21

Strana od-do

211-231

Kód UT WoS článku

000505508500013

EID výsledku v databázi Scopus

2-s2.0-85074262952