A Geochemical Study of the Teanaway River and its Tributaries, Central Washington

Document Type

Poster

Event Website

https://source2022.sched.com/

Start Date

16-5-2022

End Date

16-5-2022

Keywords

Watersheds, Chemistry of river water, Snowmelt vs Base melt

Abstract

This geochemical study examines the Teanaway River and its tributaries over a 6-month period from May 2021 to November 2021. The Teanaway River, located near Cle Elum, WA, is one of the Yakima River’s largest tributaries and lies within the Columbia River Basin. The Teanaway River is a critical resource for the local community and has recently been targeted for habitat and stream restoration through the formation of the Teanaway Community Forest. The goal of this study is to characterize the natural variations in stream water chemistry based on major element composition and stable isotope. These methods allow for the assessment of weathering reactions in tributary watersheds and how they alter the chemistry of river water, as well as the determination of mixing relationships between snowmelt and different surface waters. Three forks of the Teanaway (North, Middle, and West) were reviewed in this study as well as five smaller tributaries. Thus far, we have observed that the West and Middle Forks are similar both isotopically and in terms of major elements compared to the North Fork. These differences can be explained by differences in east-west position and geology of the subbasins drained. The West and Middle Forks drainages are further west accounting for the heavier isotope signatures. The North Fork drainage includes the ultramafic Ingalls Complex which might account for the higher Mg concentrations in its waters. Seasonal variations in water chemistry reveal higher concentrations in August and September when streamflow is dominated by baseflow and snowmelt contribution is minimal.

Faculty Mentor(s)

Carey Gazis

Department/Program

Geological Sciences

Additional Mentoring Department

Geological Sciences

Additional Mentoring Department

WASER Grant

Jackson, Megan Source Presentation.pptx (6583 kB)
Poster

Jackson, Megan Presentation.mp4 (61978 kB)
Video Presentation

Additional Files

Jackson, Megan Source Presentation.pptx (6583 kB)
Poster

Jackson, Megan Presentation.mp4 (61978 kB)
Video Presentation

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May 16th, 12:00 AM May 16th, 12:00 AM

A Geochemical Study of the Teanaway River and its Tributaries, Central Washington

This geochemical study examines the Teanaway River and its tributaries over a 6-month period from May 2021 to November 2021. The Teanaway River, located near Cle Elum, WA, is one of the Yakima River’s largest tributaries and lies within the Columbia River Basin. The Teanaway River is a critical resource for the local community and has recently been targeted for habitat and stream restoration through the formation of the Teanaway Community Forest. The goal of this study is to characterize the natural variations in stream water chemistry based on major element composition and stable isotope. These methods allow for the assessment of weathering reactions in tributary watersheds and how they alter the chemistry of river water, as well as the determination of mixing relationships between snowmelt and different surface waters. Three forks of the Teanaway (North, Middle, and West) were reviewed in this study as well as five smaller tributaries. Thus far, we have observed that the West and Middle Forks are similar both isotopically and in terms of major elements compared to the North Fork. These differences can be explained by differences in east-west position and geology of the subbasins drained. The West and Middle Forks drainages are further west accounting for the heavier isotope signatures. The North Fork drainage includes the ultramafic Ingalls Complex which might account for the higher Mg concentrations in its waters. Seasonal variations in water chemistry reveal higher concentrations in August and September when streamflow is dominated by baseflow and snowmelt contribution is minimal.

https://digitalcommons.cwu.edu/source/2022/COTS/57