Geologic Publications for Mount Rainier

Glaciers of the Olympic Mountains, Washington: The past and future 100 years

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Author(s): Andrew G. Fountain, Christina Gray, Bryce Glenn, Brian Menounos, Justin Pflug, Jon L. Riedel

Category: PUBLICATION
Document Type:
Publisher: JGR Earth Surface
Published Year: 2022
Volume: 127
Number: 4
Pages: 21
DOI Identifier: 10.1029/2022JF006670
ISBN Identifier:
Keywords:

Abstract:
In 2015, the Olympic Mountains contained 255 glaciers and perennial snowfields totaling 25.34 ± 0.27 km², half of the area in 1900, and about 0.75 ± 0.19 km³ of ice. Since 1980, glaciers shrank at a rate of −0.59 km² yr^-1 during which time 35 glaciers and 16 perennial snowfields disappeared. Area changes of Blue Glacier, the largest glacier in the study region, was a good proxy for glacier change of the entire region. Modeled glacier mass balance, based on monthly air temperature and precipitation, correlates with glacier area change. The mass balance is highly sensitive to changes in air temperature rather than precipitation, typical of maritime glaciers. In addition to increasing summer melt, warmer winter temperatures changed the phase of precipitation from snow to rain, reducing snow accumulation. Changes in glacier mass balance are highly correlated with the Pacific North American index, a proxy for atmospheric circulation patterns and controls air temperatures along the Pacific Coast of North America. Regime shifts of sea surface temperatures in the North Pacific, reflected in the Pacific Decadal Oscillation (PDO), trigger shifts in the trend of glacier mass balance. Negative ("cool") phases of the PDO are associated with glacier stability or slight mass gain whereas positive ("warm") phases are associated with mass loss and glacier retreat. Over the past century the overall retreat is due to warming air temperatures, +0.7°C in winter and +0.3°C in summer. The glaciers in the Olympic Mountains are expected to largely disappear by 2070.

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Suggested Citations:
In Text Citation:
Fountain and others (2022) or (Fountain et al., 2022)

References Citation:
Fountain, A.G., C. Gray, B. Glenn, B. Menounos, J. Pflug, and J.L. Riedel, 2022, Glaciers of the Olympic Mountains, Washington: The past and future 100 years: JGR Earth Surface, Vol. 127, No. 4, 21 p., doi: 10.1029/2022JF006670.