Earth’s skin is an interdisciplinary laboratory
In probing the life-supporting critical zone, researchers hope to protect it for future generations.
Where does water go when it rains? How does soil form? How did forests and other ecosystems develop? And how can understanding those processes inform human behaviors in the face of changes in land use and climate? Those are among the questions that scientists are asking about the critical zone—defined loosely as the region at Earth’s surface that extends from the treetops down to bedrock.
Although critical-zone research is tuned to local environments, scientists also look for broader implications. At the Boulder Creek Critical Zone Observatory in Colorado, part of the US network of nine CZOs, the main focus is on how erosion and weathering shape topography.
Floods, fires, and findings
At some CZOs, natural disasters havebecome natural experiments. Accordingto Chorover of the Catalina-Jemez CZO,almost all the long-term erosion at theobservatory takes place in the years immediatelyfollowing a wildfire. That understanding,he says, was derived froma combination of before-and-after lidarlandscape images and measurements ofberyllium-10. Concentrations of the isotope,which forms when cosmic raysbombard rock minerals, provide a measure of erosion rate. And after the devastating2013 Colorado Front Range flood,Boulder Creek researchers led bySuzanne Anderson studied landslidesand debris flow. “We found that in thecourse of a few minutes, the hill slopeslost sediment produced by 300–400 yearsof weathering,” she says.
See the full article in , January 2018.