79-8 Landform Mapping and Dust Emission Characterization in Utah’s Great Basin

Session: Soil, Dust, and Everything in Between: Current, Quaternary and Earlier Geological Processes and Records

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Abstract:

This study investigates twenty-year (2004–2024) satellite and field study of dust activities in Utah’s Great Basin. A directional distribution analysis for 283 identifiable dust plumes was conducted. Results showed that from 2004-2014, dust points were clustered in the northwest and southeastern regions. However, from 2015-2024, plumes spread further north and south of the study area. This shows the dust sources vary in time and space, with overlaps indicating that natural source zones are co-affected by human disturbances. Field validation of satellite-identified sources was conducted using the Portable In-situ Wind Erosion Laboratory (PI-SWERL). The dust emission potential of different surfaces in the region was measured, and thirteen representative locations were mapped, including Escalante Desert, Wah Wah Valley, Tule Valley, Milford Flat, Great Salt Lake Desert (GSLD), Cedar City, Beaver Bottom, and Sevier Dry Lake (SDL). At a friction velocity of 0.6 ms⁻¹, regions in Escalante Desert, Cedar City, and Beaver Bottom had the highest PM₁₀ fluxes of 9.8, 7.4, and 5.2 mg m⁻² s⁻¹, respectively. This underscores the role of sand dunes, through saltation and resident fines, in contributing to dust emissions in this region. High emissions were recorded from disturbed playa and alluvial surfaces including Milford Flat, Wah Wah Valley, and SDL. Conversely, surface roughness, crusting, and high soil moisture played a role in inhibiting emissions from the surface, as seen with low fluxes from stony surfaces on alluvial fans and physically, chemically, and biologically crusted surfaces on playas (<0.001 mg m⁻² s⁻¹). Under disturbance, some sandy surfaces displayed low emissions likely due to mixing of fines into the dust-poor parent sediments. Laboratory tests showed that higher fluxes were recorded by disturbed playa sediments, emitting >7 mg m⁻² s⁻¹. These results highlight the different dust emission potential of landforms and the effects of anthropogenic disturbance including the PI-SWERL’s ability to capture dust surface heterogeneities. Therefore, with enduring drought and land use change, emphasis should be placed on dust exposure in downwind communities.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-9357

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