OREGON STATE UNIVERSITY

Wind-borne dust may carry clues to ancient climate

05/14/2002

CORVALLIS - There may be more hitchhiking on the winds than we suspect.

Jay Noller, a professor of soil science at Oregon State University, has found that wind-born dust particles may carry new clues about how climate has changed in the Pacific Northwest. Noller presented his ideas today at a meeting of the Cordilleran Sectio n of the Geological Society of America in Corvallis.

Soil changes as climate changes, leaving behind a layered record of wet and dry spells or cold and hot periods over long geologic time scales. Soil may also contain particles blown in from great distances at particular times.

Noller has found that by tracing the source of wind-deposited particles, he may be able to correlate known events at the source with particular layers in the soil where far-flung particles came to rest.

Here is how it works. The northwest coast is a windy place. The wind that tugs at kites also carries tiny dust particles, some from as far away as central Asia. Giant firs that cloak our coastline comb that wind, and sift those particles from the air.

Conifers are among the best scavengers of wind-born particles, says Noller. They capture these particles in a web of fine needles. The particles wash into the soil where they remain as a signature of climatic events at a particular time.

Tracing the source of far-flung particles may help scientists more accurately date soil layers and increase their understanding of how our climate has changed through time.