Boulder Creek CZO: Natural Experiments to Study Critical Zone Evolution and Function

2011 Fall Cyberseminar Series

Presenter(s):
Suzanne Anderson / Boulder Creek CZO

Talk Description:

NSF established Critical Zone Observatories in late 2007 to promote interdisciplinary research on integration and coupling of Earth surface processes. Glaciers, knickpoint migration, and post-orogenic decay have shaped different parts of the Boulder Creek watershed in the Colorado Front Range over the Cenozoic. At the largest scale, we examine how these different erosion regimes shape the landscape and subsurface Critical Zone architecture. We use cosmogenic radionuclides to establish timing, and models to test possible erosion drivers. We also look at current processes operating at the hillslope scale. In one subwatershed, contrasting slope aspect provides an experiment on water delivery to the subsurface. Water flowpaths from melt of a seasonal snowpack are compared with flowpaths on adjacent slopes that experience only intermittent snow. The depth to fresh rock differs on these slopes, presumably reflecting the long-term effect of differing weathering processes and rates. Modeling will be required to link modern processes through past climates and vegetation regimes to the Critical Zone structure we see.