How Much Dust Falls on Great Basin National Park?

Written from an article by Jeff Munroe, researcher, Middlebury College, in The Midden (Great Basin National Park), Vol. 24, No. 1, Summer 2024.

How does mineral dust — lifted, carried and dropped by the wind — affect the Critical Zone of mountain ecosystems downwind? The U.S. National Science Foundation funded a network of passive dust samplers across the Intermountain West and Great Basin to find out.

The Wheeler Peak collector

• Installed: near Wheeler Peak in 2020.
• What it catches: dry dust that settles out of the air, and wet dust washed out by rain or snow.
• How: five troughs with V-shaped cross sections, filled with black glass marbles. From the site, dust storms can be seen rising from the Yelland Dry Lakebed and blowing east to the North Snake Range.

Why here?

• Location: the park sits midway between desert dust sources in southern Nevada and well-studied deposition sites in the mountains of northern Utah.
• Protection: dust can be sampled in a setting as natural as possible.
• Access: a paved road runs up to Wheeler Peak Campground.

How much

Deposition varies a little from year to year and is usually higher in summer. The average is 1.3 grams per square meter per year. That sounds small, but it equals about 4 pounds of mineral dust landing on every acre of mountain each year — a lot over years and years.

What the studies found

• Dust is local: its physical and chemical properties differ surprisingly from one mountain range to the next. Earlier work assumed airborne dust was well mixed, so the same dust fell everywhere. Instead, much of it comes from the arid lowlands right around each range — and different geology there means different dust in the nearby mountains.
• Dust builds soil: mountain soils are profoundly shaped by dust. In some cases nearly 100% of the soil wouldn't exist without slow dust deposition over time — a big deal, since soils are the foundation of ecosystems.

Under way

• Comparing Great Basin dust with "urban" dust along Utah's Wasatch Front, to see how city activity changes natural dust and how that dust affects mountains downwind.
• Comparing summer and winter dust: rates and properties by season.

Further reading

• Munroe, J.S., and others, 2023, "Regional sources control dust in the mountain critical zone of the Great Basin and Rocky Mountains, USA," Environmental Research Letters, v. 18, no. 10.
• Munroe, J.S., and others, 2024, "Mineral dust and pedogenesis in the alpine critical zone," SOIL, v. 10, no. 1.

Sources

Based on "Determining Dust Impacts on Great Basin National Park," by Jeff Munroe, Middlebury College, published by the National Park Service in The Midden and in the public domain; rewritten in hubnx's own words. The author's photograph of the collector is left out.