Reconstructing a 51-year record of catchment scale dissolved load for the Haast/Awarua River in the Southern Alps, New Zealand

Mountains dominate global denudation fluxes of solutes to the oceans despite being only a modest portion of the Earth's surface. Determining the flux of material exhumed from mountains as dissolved load, however, requires careful measurement of ionic concentrations and discharge that may be har...

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Main Authors: Mager, SM, Horton, SL
Format: Journal article
Language:English
Published: Elsevier 2023
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author Mager, SM
Horton, SL
author_facet Mager, SM
Horton, SL
author_sort Mager, SM
collection OXFORD
description Mountains dominate global denudation fluxes of solutes to the oceans despite being only a modest portion of the Earth's surface. Determining the flux of material exhumed from mountains as dissolved load, however, requires careful measurement of ionic concentrations and discharge that may be hard to obtain. We reconstruct the dissolved load and total dissolved solids yield from pre-existing discharge measurements and 32-years on monthly water quality sampling in a headwater catchment in the Southern Alps/Ka Tiritiri o te Moana, New Zealand. The dissolved weathering yield of the Haast/Awarua River for 1971–2020 was 218 ± 48 t km−2 a−1. The flux of dissolved material from the mountain catchment has a seasonal signal, with higher TDS concentrations during winter, but greater chemical weathering yields during summer. Hydrographic behaviour is an important control of weathering yields with 70 % of dissolved load being transported during event flow. Variations in chemical weathering yields are sensitive to changes in stream flow associated with broader climate oscillations, which will have a direct effect on estimations of chemical weathering rates since dissolved flux is strongly correlated to changes in stream flow.
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spelling oxford-uuid:ed1cd2dd-e887-4406-bb8f-880ed09a75f12023-11-23T14:03:20ZReconstructing a 51-year record of catchment scale dissolved load for the Haast/Awarua River in the Southern Alps, New ZealandJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:ed1cd2dd-e887-4406-bb8f-880ed09a75f1EnglishSymplectic ElementsElsevier2023Mager, SMHorton, SLMountains dominate global denudation fluxes of solutes to the oceans despite being only a modest portion of the Earth's surface. Determining the flux of material exhumed from mountains as dissolved load, however, requires careful measurement of ionic concentrations and discharge that may be hard to obtain. We reconstruct the dissolved load and total dissolved solids yield from pre-existing discharge measurements and 32-years on monthly water quality sampling in a headwater catchment in the Southern Alps/Ka Tiritiri o te Moana, New Zealand. The dissolved weathering yield of the Haast/Awarua River for 1971–2020 was 218 ± 48 t km−2 a−1. The flux of dissolved material from the mountain catchment has a seasonal signal, with higher TDS concentrations during winter, but greater chemical weathering yields during summer. Hydrographic behaviour is an important control of weathering yields with 70 % of dissolved load being transported during event flow. Variations in chemical weathering yields are sensitive to changes in stream flow associated with broader climate oscillations, which will have a direct effect on estimations of chemical weathering rates since dissolved flux is strongly correlated to changes in stream flow.
spellingShingle Mager, SM
Horton, SL
Reconstructing a 51-year record of catchment scale dissolved load for the Haast/Awarua River in the Southern Alps, New Zealand
title Reconstructing a 51-year record of catchment scale dissolved load for the Haast/Awarua River in the Southern Alps, New Zealand
title_full Reconstructing a 51-year record of catchment scale dissolved load for the Haast/Awarua River in the Southern Alps, New Zealand
title_fullStr Reconstructing a 51-year record of catchment scale dissolved load for the Haast/Awarua River in the Southern Alps, New Zealand
title_full_unstemmed Reconstructing a 51-year record of catchment scale dissolved load for the Haast/Awarua River in the Southern Alps, New Zealand
title_short Reconstructing a 51-year record of catchment scale dissolved load for the Haast/Awarua River in the Southern Alps, New Zealand
title_sort reconstructing a 51 year record of catchment scale dissolved load for the haast awarua river in the southern alps new zealand
work_keys_str_mv AT magersm reconstructinga51yearrecordofcatchmentscaledissolvedloadforthehaastawaruariverinthesouthernalpsnewzealand
AT hortonsl reconstructinga51yearrecordofcatchmentscaledissolvedloadforthehaastawaruariverinthesouthernalpsnewzealand