Weathering Dynamics Under Contrasting Greenland Ice Sheet Catchments

Alejandra Urra; Jemma Wadham; Jon R. Hawkings; Jon Telling; Jade E. Hatton; Jacob C. Yde; Bent Hasholt; Dirk van As; Maya P. Bhatia; Peter Nienow

doi:10.3389/feart.2019.00299

Weathering Dynamics Under Contrasting Greenland Ice Sheet Catchments

Alejandra Urra, Jemma Wadham, Jon R. Hawkings, Jon Telling, Jade E. Hatton, Jacob C. Yde, Bent Hasholt, Dirk van As, Maya P. Bhatia, Peter Nienow

LUKKET: Geografi

8 Citationer (Scopus)

2 Downloads (Pure)

Abstract

Chemical weathering dynamics in Greenland Ice Sheet (GrIS) catchments are largely unknown, due to a scarcity of field data. This paper presents the most comprehensive study to date of chemical weathering rates from four GrIS catchments of contrasting size. Cationic denudation rates varied greatly between catchments studied (2.6–37.6 tons km^–2 a^–1, world mean = 11.9 tons km^–2 a^–1), but were of the same order of magnitude to the world non-glacial riverine mean, and are greater than those documented in some major temperate rivers catchments (e.g., Mississippi (1.3 tons km^–2 a^–1) and Nile (0.4 tons km^–2 a^–1) rivers). These high chemical denudation rates indicate that the GrIS is a potential source of solute to downstream environments. Dissolved silica yields, indicative of silicate weathering rates, also varied by an order of magnitude, with upper values similar to the world mean (0.2–3.8 tons km^–2 a^–1, world mean = 3.53 tons km^–2 a^–1). Elevated chemical weathering rates in GrIS catchments are strongly influenced by the specific discharge, which drives flushing of the subglacial environment and physical erosion of the ice sheet bed. The direct relationship between specific discharge and chemical denudation rates supports the hypothesis that GrIS chemical weathering rates and solute fluxes are likely to increase with enhanced melt rates in a warming climate.

Originalsprog	Engelsk
Artikelnummer	299
Tidsskrift	Frontiers in Earth Science
Vol/bind	7
Antal sider	15
ISSN	2296-6463
DOI	https://doi.org/10.3389/feart.2019.00299
Status	Udgivet - 26 nov. 2019

Adgang til dokumentet

10.3389/feart.2019.00299Licens: CC BY

Weathering Dynamics Under Contrasting Greenland Ice Sheet CatchmentsForlagets udgivne version, 2,76 MBLicens: CC BY

Citationsformater

@article{5f0870db08b845b19ad43c45648a45f1,

title = "Weathering Dynamics Under Contrasting Greenland Ice Sheet Catchments",

abstract = "Chemical weathering dynamics in Greenland Ice Sheet (GrIS) catchments are largely unknown, due to a scarcity of field data. This paper presents the most comprehensive study to date of chemical weathering rates from four GrIS catchments of contrasting size. Cationic denudation rates varied greatly between catchments studied (2.6–37.6 tons km–2 a–1, world mean = 11.9 tons km–2 a–1), but were of the same order of magnitude to the world non-glacial riverine mean, and are greater than those documented in some major temperate rivers catchments (e.g., Mississippi (1.3 tons km–2 a–1) and Nile (0.4 tons km–2 a–1) rivers). These high chemical denudation rates indicate that the GrIS is a potential source of solute to downstream environments. Dissolved silica yields, indicative of silicate weathering rates, also varied by an order of magnitude, with upper values similar to the world mean (0.2–3.8 tons km–2 a–1, world mean = 3.53 tons km–2 a–1). Elevated chemical weathering rates in GrIS catchments are strongly influenced by the specific discharge, which drives flushing of the subglacial environment and physical erosion of the ice sheet bed. The direct relationship between specific discharge and chemical denudation rates supports the hypothesis that GrIS chemical weathering rates and solute fluxes are likely to increase with enhanced melt rates in a warming climate.",

keywords = "Greenland, ice sheet, glaciers, solute fluxes, cations, silica, weathering",

author = "Alejandra Urra and Jemma Wadham and Hawkings, {Jon R.} and Jon Telling and Hatton, {Jade E.} and Yde, {Jacob C.} and Bent Hasholt and {van As}, Dirk and Bhatia, {Maya P.} and Peter Nienow",

year = "2019",

month = nov,

day = "26",

doi = "10.3389/feart.2019.00299",

language = "English",

volume = "7",

journal = "Frontiers in Earth Science",

issn = "2296-6463",

publisher = "Frontiers Research Foundation",

}

TY - JOUR

T1 - Weathering Dynamics Under Contrasting Greenland Ice Sheet Catchments

AU - Urra, Alejandra

AU - Wadham, Jemma

AU - Hawkings, Jon R.

AU - Telling, Jon

AU - Hatton, Jade E.

AU - Yde, Jacob C.

AU - Hasholt, Bent

AU - van As, Dirk

AU - Bhatia, Maya P.

AU - Nienow, Peter

PY - 2019/11/26

Y1 - 2019/11/26

N2 - Chemical weathering dynamics in Greenland Ice Sheet (GrIS) catchments are largely unknown, due to a scarcity of field data. This paper presents the most comprehensive study to date of chemical weathering rates from four GrIS catchments of contrasting size. Cationic denudation rates varied greatly between catchments studied (2.6–37.6 tons km–2 a–1, world mean = 11.9 tons km–2 a–1), but were of the same order of magnitude to the world non-glacial riverine mean, and are greater than those documented in some major temperate rivers catchments (e.g., Mississippi (1.3 tons km–2 a–1) and Nile (0.4 tons km–2 a–1) rivers). These high chemical denudation rates indicate that the GrIS is a potential source of solute to downstream environments. Dissolved silica yields, indicative of silicate weathering rates, also varied by an order of magnitude, with upper values similar to the world mean (0.2–3.8 tons km–2 a–1, world mean = 3.53 tons km–2 a–1). Elevated chemical weathering rates in GrIS catchments are strongly influenced by the specific discharge, which drives flushing of the subglacial environment and physical erosion of the ice sheet bed. The direct relationship between specific discharge and chemical denudation rates supports the hypothesis that GrIS chemical weathering rates and solute fluxes are likely to increase with enhanced melt rates in a warming climate.

AB - Chemical weathering dynamics in Greenland Ice Sheet (GrIS) catchments are largely unknown, due to a scarcity of field data. This paper presents the most comprehensive study to date of chemical weathering rates from four GrIS catchments of contrasting size. Cationic denudation rates varied greatly between catchments studied (2.6–37.6 tons km–2 a–1, world mean = 11.9 tons km–2 a–1), but were of the same order of magnitude to the world non-glacial riverine mean, and are greater than those documented in some major temperate rivers catchments (e.g., Mississippi (1.3 tons km–2 a–1) and Nile (0.4 tons km–2 a–1) rivers). These high chemical denudation rates indicate that the GrIS is a potential source of solute to downstream environments. Dissolved silica yields, indicative of silicate weathering rates, also varied by an order of magnitude, with upper values similar to the world mean (0.2–3.8 tons km–2 a–1, world mean = 3.53 tons km–2 a–1). Elevated chemical weathering rates in GrIS catchments are strongly influenced by the specific discharge, which drives flushing of the subglacial environment and physical erosion of the ice sheet bed. The direct relationship between specific discharge and chemical denudation rates supports the hypothesis that GrIS chemical weathering rates and solute fluxes are likely to increase with enhanced melt rates in a warming climate.

KW - Greenland

KW - ice sheet

KW - glaciers

KW - solute fluxes

KW - cations

KW - silica

KW - weathering

U2 - 10.3389/feart.2019.00299

DO - 10.3389/feart.2019.00299

M3 - Journal article

SN - 2296-6463

VL - 7

JO - Frontiers in Earth Science

JF - Frontiers in Earth Science

M1 - 299

ER -

Weathering Dynamics Under Contrasting Greenland Ice Sheet Catchments

Abstract

Adgang til dokumentet

Fingeraftryk

Citationsformater