The provenance and persistence of the perennial Río Loa in the Atacama Desert: links between crustal processes and surface hydrology

The Río Loa is a perennial river that crosses the Atacama Desert. A basin-wide survey enables for the first time, the hydrologic regime origin, persistence and processes to be identified. Perennial baseflow in the Ríos Loa and Salado largely originates from intra-arc aquifers which are poorly known....

Full description

Bibliographic Details
Main Author: John Houston
Format: Article
Language:English
Published: Frontiers Media S.A. 2023-12-01
Series:Frontiers in Earth Science
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/feart.2023.1310088/full
_version_ 1797387381097103360
author John Houston
author_facet John Houston
author_sort John Houston
collection DOAJ
description The Río Loa is a perennial river that crosses the Atacama Desert. A basin-wide survey enables for the first time, the hydrologic regime origin, persistence and processes to be identified. Perennial baseflow in the Ríos Loa and Salado largely originates from intra-arc aquifers which are poorly known. However, the data indicate that despite flood flow being largely confined to the summer (DJF) season, sufficient storage exists in these aquifers to maintain year-round stream flow from high-altitude, across the Atacama Desert to the coast. The intra-arc aquifers of the Western Cordillera receive recharge from time-variable precipitation infiltration and time-invariant lithospheric inputs. Lithospheric inputs potentially include slab/mantle dehydration, upper crustal melt devolatilization and/or thermally induced upflow of deeply penetrating meteoric water through buried evaporites or carbonates. Downstream, aquifers in the Pre-Andean basins variably interact with surface water, depending on location, river stage and time of year, but they do not supply significant additional sources of baseflow. Hydrochemical processes include those related to volcanic activity, soil carbonate generation, silicate weathering, CO2 degassing and calcite precipitation. Solutes undergo concentration by evaporation, gypsum dissolution, and are further affected by localized NO3, and SO4 inputs and mixing with saline waters. Stable isotopes reveal subcatchment specific precipitation and evaporation, whilst carbon and tritium isotopes are used to analyze recharge sources and processes in the intra-arc aquifers and downstream mixing.
first_indexed 2024-03-08T22:23:18Z
format Article
id doaj.art-39639bb5c5eb475a9e23fecb9df42960
institution Directory Open Access Journal
issn 2296-6463
language English
last_indexed 2024-03-08T22:23:18Z
publishDate 2023-12-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Earth Science
spelling doaj.art-39639bb5c5eb475a9e23fecb9df429602023-12-18T11:22:57ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632023-12-011110.3389/feart.2023.13100881310088The provenance and persistence of the perennial Río Loa in the Atacama Desert: links between crustal processes and surface hydrologyJohn HoustonThe Río Loa is a perennial river that crosses the Atacama Desert. A basin-wide survey enables for the first time, the hydrologic regime origin, persistence and processes to be identified. Perennial baseflow in the Ríos Loa and Salado largely originates from intra-arc aquifers which are poorly known. However, the data indicate that despite flood flow being largely confined to the summer (DJF) season, sufficient storage exists in these aquifers to maintain year-round stream flow from high-altitude, across the Atacama Desert to the coast. The intra-arc aquifers of the Western Cordillera receive recharge from time-variable precipitation infiltration and time-invariant lithospheric inputs. Lithospheric inputs potentially include slab/mantle dehydration, upper crustal melt devolatilization and/or thermally induced upflow of deeply penetrating meteoric water through buried evaporites or carbonates. Downstream, aquifers in the Pre-Andean basins variably interact with surface water, depending on location, river stage and time of year, but they do not supply significant additional sources of baseflow. Hydrochemical processes include those related to volcanic activity, soil carbonate generation, silicate weathering, CO2 degassing and calcite precipitation. Solutes undergo concentration by evaporation, gypsum dissolution, and are further affected by localized NO3, and SO4 inputs and mixing with saline waters. Stable isotopes reveal subcatchment specific precipitation and evaporation, whilst carbon and tritium isotopes are used to analyze recharge sources and processes in the intra-arc aquifers and downstream mixing.https://www.frontiersin.org/articles/10.3389/feart.2023.1310088/fullAtacamavolcanic arcbaseflowisotope hydrologygroundwater recharge
spellingShingle John Houston
The provenance and persistence of the perennial Río Loa in the Atacama Desert: links between crustal processes and surface hydrology
Frontiers in Earth Science
Atacama
volcanic arc
baseflow
isotope hydrology
groundwater recharge
title The provenance and persistence of the perennial Río Loa in the Atacama Desert: links between crustal processes and surface hydrology
title_full The provenance and persistence of the perennial Río Loa in the Atacama Desert: links between crustal processes and surface hydrology
title_fullStr The provenance and persistence of the perennial Río Loa in the Atacama Desert: links between crustal processes and surface hydrology
title_full_unstemmed The provenance and persistence of the perennial Río Loa in the Atacama Desert: links between crustal processes and surface hydrology
title_short The provenance and persistence of the perennial Río Loa in the Atacama Desert: links between crustal processes and surface hydrology
title_sort provenance and persistence of the perennial rio loa in the atacama desert links between crustal processes and surface hydrology
topic Atacama
volcanic arc
baseflow
isotope hydrology
groundwater recharge
url https://www.frontiersin.org/articles/10.3389/feart.2023.1310088/full
work_keys_str_mv AT johnhouston theprovenanceandpersistenceoftheperennialrioloaintheatacamadesertlinksbetweencrustalprocessesandsurfacehydrology
AT johnhouston provenanceandpersistenceoftheperennialrioloaintheatacamadesertlinksbetweencrustalprocessesandsurfacehydrology