A proposed NSF initiative
http://www.wssc.psu.edu
Slide by Pete Sak, Penn State
How does Earth’s weathering engine grind rock to
nourish ecosystems, carve terrestrial landscapes,
and sequester atmospheric carbon dioxide?
The Critical Zone:
We know less about
soil chemistry and
structure than global
ocean chemistry and
structure
 Rates of soil degradation
are increasing globally
 Northern soils are
defrosting
Between 40 and 50% of the land surface
of the planet has been transformed by
human action; in addition, much of that
transformation plus many agricultural
practices cause loss of topsoil (in the
1980s, the world lost topsoil equivalent to
half of the topsoil on US cropland, in
excess of soil formation)
Annual fixation of nitrogen has doubled
through the action of humans since the
beginning of the 20th century
Naturally-occurring groundwater constituents: arsenic
Photo credit: © 1999-2001 TH, MP, AY and RW
http://phys4.harvard.edu/~wilson/arsenic_project_pictures2.html
Slide courtesy of Janet Hering
Picture credit: British Geological Survey
Mycorrhizal mycelia are biosensors that direct growth and
carbon flow into areas of nutrients or weatherable minerals
From Leake et al. Tree Physiol. 21. 2001
How are soil resources and the weathering
engine affected by global environmental change?
What are the rates
and mechanisms of
sequestration of
carbon in modern
soils?
CO2
Sequestration
How do soils and
rocks add or remove
toxins to water
resources, affecting
human health?
Nutrient Uptake
Into Plants
Soil
Rock
Chemistry
of Groundwater
How do soils control the
sources and sinks of
nutrients in ecosystems?
Landform
evolution
How do the rates of
transformation of bedrock
into soil compare to the
rates of degradation of
soil worldwide?
WSSC Organizing Workshop
Participants
• Organizing Committee: Sue Brantley (Penn State University) ,
Lou Derry (Cornell University), Lee Kump (Penn State
University), Art White (U.S. Geological Survey), Oliver
Chadwick (University of Santa Barbara)
• Carl Steefel (Lawrence Livermore National Laboratory),
Claudia Mora (University of Tennessee), Dan Richter (Duke
University), Enriqueta Barrera (NSF), Janet Hering (California
Institute of Technology), Jerome Gaillardet (Institut de
Physique du Globe de Paris), Jim Kirchner (University of
California, Berkeley), Joel Blum (University of Michigan), Joel
Moore (Penn State), Jon Chorover (University of Arizona),
Ruth Blake (Yale University), Siggi Gislason, (University of
Iceland), Suzanne Anderson (University of Colorado, Boulder),
Tim Drever (University of Wyoming), Walt Snyder (NSF)
Kaolinite + gibbsite + Fe oxides
Basalt
Cyanobacteria extracting phosphate from apatite surface
Sand Shadows and Shifting Landscapes / 25
Marita Gootee
http://www2.msstate.edu/~gootee/pages/25.htm
Why don’t we know more about
soils?
Chemistry
Biology
Physics
Time
Extreme chemical, physical,
and biological heterogeneity
Why now?...
New developments in weathering system
science
• Cosmogenic isotopes allow dating of exposure surfaces
• New isotopes and other tracers can document biological cycling,
age of comminution, rates of dissolution near equilibrium
• New molecular biological techniques allow the investigation of
geobiological phenomena
• Geomorphological models are now available that elucidate controls
on weathering
• Reactive transport models allow investigation of multicomponent,
multiphase systems
• New nanoscale spectroscopies allow investigation of chemistry of
mineral-soil-water-biota interface
• Environmental sensors are becoming available for investigating field
sites
Driving Questions for WSSC
•
•
•
•
In a given environment and at various
scales, how can the dominant factors
controlling chemical weathering be
identified and their effects be
quantified?
In what ways are physical, chemical,
hydrological and biological weathering
processes coupled, and how can these
couplings be elucidated and
quantified?
How can we advance our ability to
predict weathering processes over the
range of pertinent spatial scales from
mineral surfaces to laboratory reactors
to soils to catchments to global?
How do weathering processes change
and evolve over human timescales
and over geologic time, and what
approaches are useful in predicting the
temporal evolution of weathering
products and elemental fluxes?
Soil photo by Fimmen,
Vasudevan, & Richter
Driving Questions for WSSC
•
•
•
•
In a given environment and at various
scales, how can the dominant factors
controlling chemical weathering be
identified and their effects be
quantified?
In what ways are physical, chemical,
hydrological and biological weathering
processes coupled, and how can these
couplings be elucidated and
quantified?
How can we advance our ability to
predict weathering processes over the
range of pertinent spatial scales from
mineral surfaces to laboratory reactors
to soils to catchments to global?
How do weathering processes change
and evolve over human timescales
and over geologic time, and what
approaches are useful in predicting the
temporal evolution of weathering
products and elemental fluxes?
Slide from Bjorn Jamtveit, photograph
from South Africa
Driving Questions for WSSC
•
•
•
•
In a given environment and at various
scales, how can the dominant factors
controlling chemical weathering be
identified and their effects be
quantified?
In what ways are physical, chemical,
hydrological and biological weathering
processes coupled, and how can these
couplings be elucidated and
quantified?
How can we advance our ability to
predict weathering processes over the
range of pertinent spatial scales from
mineral surfaces to laboratory reactors
to soils to catchments to global?
How do weathering processes change
and evolve over human timescales
and over geologic time, and what
approaches are useful in predicting the
temporal evolution of weathering
products and elemental fluxes?
Driving Questions for WSSC
•
•
•
•
In a given environment and at various
scales, how can the dominant factors
controlling chemical weathering be
identified and their effects be
quantified?
In what ways are physical, chemical,
hydrological and biological weathering
processes coupled, and how can these
couplings be elucidated and
quantified?
How can we advance our ability to
predict weathering processes over the
range of pertinent spatial scales from
mineral surfaces to laboratory reactors
to soils to catchments to global?
How do weathering processes change
and evolve over human timescales
and over geologic time, and what
approaches are useful in predicting the
temporal evolution of weathering
products and elemental fluxes?
2.2-billion-years-old paleosol,
Waterval Onder, South Africa
Photo by Greg Retallack, University of Oregon
The WSSC proposal is being
developed to establish …
• A consortium or coalition to promote the systematic and
standardized investigation of rates of biogeochemical
processes
• A web-based data repository for weathering science data
• A set of instrumented baseline (node) field sites, one of
which is a Soil Observatory
• Technical support and instrumentation for backbone field
sites
• Structure for improving community models of WSS
• An integrative center for weathering science
• A series of meetings for consortia members to develop
the weathering community
WSS Consortium
• A group of universities with PIs
investigating weathering system science
• Current WSSC members include fifty
universities
Small number of nested, instrumented NODE sites
Instrumented
Catchment
Instrumented
Soil Sites
Proposed by the community
Node Sites =
Critical Zone Laboratories
• A node site would be a “tool” that all
biogeoscientists could use to investigate
weathering. Site would be open to all for
investigation using all chemical or physical or
hydrological or ecological techniques. Site would
establish the “STP” of weathering system
science. Site could be a Soil Observatory with
both sampling and imaging capability
What sites are have been suggested
for critical zone laboratories?
•
•
•
•
•
•
•
•
•
Puerto Rico (LTER site)
Wind River (chronosequence)
Mancos Shale
West Indies site: Guadeloupe
Eel River site
Panola GA (WEBB site)
Hawaii (chronosequence)
Huntingdon Forest Preserve
Shale Hills PA
Criteria under Discussion for Node Sites
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Lithology: well-known, homogeneous, mineralogy amenable to answering the important question, for example
representative of large crustal areas, simple 2o mineralogy, grain size and surf area)
Geomorphologically well understood
Variable soil thickness
Accessibility to the bedrock-interface (observatory at that interface?)
Climate (temperature, precipitation, seasonality, form of ppn: major climatic regimes (boreal forests,
temperate sites, tropical sites)
Age of soil, Chronosequence?
Previously studied?
Remote vs. easily accessible
Age of bedrock: older better (fpr isotopic reasons)
Exposure age : is it measurable?
Pristine vs anthropogenically impacted
Biotypes (grassland, forest (e.g. tropical rain forest, temperate deciduous, boreal coniferous)
Is site manipulatable?
Steady state vs transient (this could be with respect to soil thickness, wrt ecosystem)
Homogeneous in terms of important variables
Atmospheric characteristics (pH of rain? Dust? CO2 content, other contaminants?)
Physical/chemical issues (known uplift rates, known physical denudation rates, known dominant erosional
processes and their potential to winnow the regolith, bedrock vs alluvial material, tectonic regime, bedrock
permeability, time since grinding of the grains)
Hydrological issues (fracture flow vs porous media flow, unsaturated vs saturated soils, groundwater vs soil
zone, grain size and surface area)
How does the site allow us to upscale to larger scale processes…is it a good site to allow upscaling? Is it a
site amenable to lab scale modelling (ie running exps in the lab)
Uniqueness …
Site Matrix
Describing
Node and
BackBone Sites
Climate
Lithology
Backbone Sites
Node sites
BackBone Sites
• Many sites distributed over a range of
environmental variables
• Proposed by community
• Standard data sets collected for each site
• Data might include soil chemistry,
mineralogy, organic content, grain size
distribution, mineral surface area,
compiled as a function of depth to bedrock
Weathering System Science Consortium
Data and Information System
(WSSC-DIS)
Metadata
Catalog
WSSC Database
WSSC Central Server
Internet
WSSCR Node
WSSCR Node
Science Community
NOAM-SOIL
Work In Progress
• North American Extent
• Soil Physical and
Hydraulic Properties
• Geospatial Database
Series of WSSC Meetings
• Conferences for all aspects of weathering
from biological to chemical to physical to
hydrological
• Conferences that will move the science
forward by stimulating cross-disciplinary
discussion
• Yearly
• International
Schedule
• Workshop with 20 participants, October 2003
• Open meeting at Fall AGU, release of draft call for an
initiative
• White paper reviewed by community and published in
EOS, Spring 2004
• Open meeting, June 2004 at the Goldschmidt Meeting,
Copenhagen Denmark
• Open meeting, June 2004 at the WRI-11 meeting,
Saratoga Springs NY, USA
• EU and UK workshops for international WSSC
participants October, 2004: London
• International outreach for field sites (e.g. West Indies,
October 2004)
• Workshop to provide programmatic details, Winter or
spring 2005
• Proposal to NSF, 2005
Our focus is the North
American weathering
community. The need is for
a funding paradigm that will
involve the international
community.
A coordinated worldwide effort is
needed to investigate the soil
resource systematically.
Research must investigate
controls on soil formation and
destruction including
anthropogenic factors such as
climate and land use change.
International
http://www.wssc.psu.edu