Diurnal chemistry of two contrasting stream types, Taylor Valley, McMurdo Dry Valley Region, Antarctica

Numerous ephemeral streams flow within the McMurdo Dry Valley Region of Antarctica that transport glacial meltwater to perennially ice-covered, closed-basin lakes during the austral summer. The diurnal behavior for two Taylor Valley streams of different character was examined during the summer of 20...

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Bibliographic Details
Published in:E3S Web of Conferences
Main Authors: Harmon Russell S., Leslie Deborah L., Lyons W. Berry, Welch Kathleen A., McKnight Diane M.
Format: Article in Journal/Newspaper
Language:English
French
Published: EDP Sciences 2019
Subjects:
geo
Online Access:https://doi.org/10.1051/e3sconf/20199801020
https://www.e3s-conferences.org/articles/e3sconf/pdf/2019/24/e3sconf_wri-162018_01020.pdf
https://doaj.org/article/341d2cc7dad54cc589a3373912ed5b0a
Description
Summary:Numerous ephemeral streams flow within the McMurdo Dry Valley Region of Antarctica that transport glacial meltwater to perennially ice-covered, closed-basin lakes during the austral summer. The diurnal behavior for two Taylor Valley streams of different character was examined during the summer of 2010-11. Andersen Creek is a short, 1st-order proglacial stream, whereas Von Guerard Stream is a long, high-order stream with an extensive hyporheic zone that has a substantial cyanobacterial algal mat community in its middle reaches. Both streams display strong daily cycles for temperature, electrical conductivity, dissolved oxygen, and pH. Conductivity varies in concert with flow, with solute dilution occurring during the daily high-flow pulse. Dissolved oxygen co-varies strongly with pH at Andersen Creek but not for Von Guerard Stream. Each stream has a distinct geochemical character that for Andersen Creek is a direct reflection of its glacial source, unmodified by secondary effects, whereas that for Von Guerard Stream is modulated by its resident algal mat community and through extensive hyporheic zone interaction and exchange.