Science Opportunities - Basic Research Opportunities in Earth Science - page 34

more quantitative exploration of the dynamic interrelationships between
tectonics, climate, soil diversity, and landscapes.
• Microprobe, X-ray diffraction, scanning and transmission electron
microscopy, X-ray tomography, and microchemical probes can be used to
map the architecture of soils and to investigate material properties at the
atomic-scale resolution needed for understanding sorption-desorption
kinetics and other equilibrium processes. 5
• Ground-penetrating radar and three-dimensional seismic imaging of
sedimentary deposits permit modeling and prediction of physical
properties of heterogeneous sediments in three dimensions. 6
Chemostratigraphic techniques can be used to correlate sediments among
sedimentary basins, particularly between onshore and offshore basins.
• In situ and aircraft sensors for measuring circulation patterns and mapping
the bathymetry and substrate of the near-shore environment, combined
with analysis of geochemical and sedimentological components and
fluxes, can be used to quantify the variability of the geological,
biological, and atmospheric components of coastal ecosystems.
Need for Coordinated Field Work and Integrated Modeling
The integration of disciplinary research is the key to future progress in the
science of the Critical Zone. This theme permeates the discussion of many other
aspects of Earth science in this report, but, in the case of the Critical Zone, it
presents some special challenges, in part because of the sheer number of the
disciplines and the diversity of their approaches, but more profoundly because of
the spatial scales intrinsic to the scientific issues. Although Critical Zone
processes often involve the global aspects of atmospheric and oceanic transport,
many of the most intense interactions occur in relatively localized regions of the
solid Earth—for example, over dimensions less than the characteristic horizontal
variations in topography and near-surface geology (tens to hundreds of
kilometers) or the thickness of the zone itself (about a kilometer). Indeed, much
of the science to be done will require the in situ study of microscopic processes
that are subject to numerous contingencies— physical, chemical, and biological
—which vary from one surface environment to the next. Not surprisingly,
disciplinary integration has proceeded more
5 Opportunities in Basic Soil Science Research, G. Sposito and R.J. Reginato, eds., Soil
Science Society of America, Madison, Wisconsin, 129 pp., 1992.
6 Sedimentary Systems in Space and Time: High Priority NSF Research Initiatives in
Sedimentary Geology, results of a workshop held in Boulder, Colorado, March 27-29,
1999.