Chemical fluxes and sensitivity to acidification of two high-elevation catchments in southern Wyoming

• Published in: Journal of hydrology (Amsterdam) Vol. 173; no. 1; pp. 165 - 189
• Main Authors: Reuss, J.O., Vertucci, F.A., Musselman, R.C., Sommerfeld, R.A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 1995; Elsevier Science
• Subjects: Earth sciences; Earth, ocean, space; Exact sciences and technology; Freshwater; Geochemistry; Hydrology; Hydrology. Hydrogeology; Mineralogy; Silicates; Water geochemistry; Western U.S; United States; Wyoming; North America; glaciers; potassium; acidification; sulfates; nitrates; quartzites; drainage basins; precipitation; bedrock; hydrochemistry; discharge; pH; lakes; anions; cations; calcium; atmospheric precipitation; runoff; magnesium; metamorphic rocks; meltwater; surface water; sodium; snow; hydrographs
• ISSN: 0022-1694; 1879-2707
• DOI: 10.1016/0022-1694(95)02701-P

Hydrological and chemical fluxes were examined for East and West Glacier Lakes and their adjacent high-elevation (3200—3700 m) catchments in the Snowy Range of southern Wyoming. Both lakes are approximately 3 ha, but the East Glacier catchment (29 ha) is about half the size of West Glacier. Bedrock is primarily quartzite that has been heavily fractured and crossed with mafic intrusions. Precipitation pH averages about 5.4–5.5, and weighted mean acid neutralizing capacities (ANC) of the discharge are about 50 μequiv.1 −1 for East Glacier lake and 39 μequiv.1 −1 for West Glacier, while the respective annual base cation removals are about 36 mequiv. m −2 and 73 mequiv. m −2. Two West Glacier tributary streams average less than 10 μequiv. 1 −1 ANC, but solute concentrations during the early snow melt are more than five times those found in midsummer. It is inferred that these early high concentrations primarily are due to early elution of solutes from the snowpack rather than the displacement of high-concentration groundwater, but the cations may be substantially affected by exchange reactions. Preliminary evaluation suggests that the mean ANC of both lakes would fall below zero if precipitation pH were to fall to 4.2–4.3. Episodic acidity during snowmelt and acidification of tributary streams would likely occur at a somewhat higher precipitation pH.