Abstract
2015: Glacier status and contribution to streamflow in the Olympic Mountains, Washington
J.L. Riedel, Steve Wilson, William Baccus, Michael Larrabee, T.J. Fudge, and Andrew Fountain
The Olympic Peninsula, Washington, USA, currently holds 184 alpine glaciers larger than 0.01 km² and their combined area is 30.2 ± 0.95km². Only four glaciers are >1km² and 120 of the others are ‑¹ (1900–80) to 0.54 km² a‑¹ (1980–2009). Thinning rates on four of the largest glaciers averaged nearly 1ma‑¹ from 1987 to 2010, resulting in estimated volume losses of 17–24%. Combined glacial snow, firn and ice melt in the Hoh watershed is in the range 63–79 ± 7 × 106 m³, or 9–15% of total May–September streamflow. In the critical August–September period, the glacial fraction of total basin runoff increases to 18–30%, with one-third of the water directly from glacial ice (i.e. not snow and firn). Glaciers in the Elwha basin produce 12–15 ± 1.3 × 106 m³ (2.5–4.0%), while those in the Dungeness basin contribute 2.5–3.1 ± 0.28 × 106 m³ (3.0–3.8%).