brantley_czen_wun_2009 - Critical Zone Exploration Network

tansygoobertownInternet και Εφαρμογές Web

8 Δεκ 2013 (πριν από 3 χρόνια και 10 μήνες)

59 εμφανίσεις

Susan L. Brantley. Penn State

Sept 9, 2009

www.czen.org

Penn State

Introduction to Critical Zone
Science

The Critical Zone = the zone extending
from the outer vegetation envelope to
the lower limit of groundwater

Anderson et al., 2004

How can we quantitatively predict
(
earthcast
) the response of the earth
surface to natural and human perturbation?


To do this, we need…



new techniques

to measure the controlling variables at the relevant
scales of time and space


comprehensive, long
-
term, and systematic
observations
of the key
variables needed to
earthcast


measurement of the
thermodynamic and kinetic data

necessary to
predict the fluxes of matter and energy occurring at interfaces
between reservoirs with very different dynamics


development of
conceptual models


development of a complete set of
governing equations for surface
processes


improvements in modeling
of dynamical complexities and emergent
phenomena

To answer this question requires
scientists who can cross disciplines and
also think across timescales that vary
from seconds to tens of millions of years


Workshop with 20 participants (Baltimore, October 2003)


WSSC website (
http://www.wssc.psu.edu/
)


Open meeting at AGU (Dec. 2003)


Anderson et al. (2004) published in EOS


Goldschmidt , Copenhagen, open meeting (2004)


Open meeting at WRI
-
11, Saratoga Springs (June 2004)


WSSC European science meeting (England, Oct. 2004)


WSSC UK scientists meeting (October 2004)


2005 Goldschmidt conference: Earth’s Weathering Engine


2
nd

WSSC Workshop, January 2005, at NSF, WSSC renamed
as CZEN


Univ of Delaware Frontiers of Crit Zone meeting, 2006


Data and Date Structures Meeting at Penn State, 2007


International efforts within CZEN, Vancouver Goldschmidt, 2008


Unsuccessful Science and Technology Center proposal, 2009


WUN Meeting at Penn State Sept 09


CZO meeting at Penn State Sept 09


Frontiers of CZ Science: GeoBio, Smithsonian, Oct 09

Partial History: WSSC and CZEN

Workshop report
from the Univ of
Delaware
meeting



Download from
www.czen.org

The Tool that this Community Needs


A network of observatories (
Critical Zone
Exploration Network, CZEN)
that all Critical
Zone scientists can work on together to
investigate how environmental variables control
CZ processes


CZEN would be open for investigation using all
chemical or physical or hydrological or
ecological or molecular biological or geological
(etc.) techniques


(and is developing)

Climate

Lithology


Critical Zone Exploration Network

Disturbance

Why a network?


Network can explore one environmental variable
while keeping other variables constant


Network allows comparison of the same data
measured in the same way at multiple sites


Network allows understanding of broad patterns
of behavior


Network can create community among scientists
and generate interdisciplinary understanding

CZEN Seed Sites funded in 2006 (10) and 2008 (3)

Calhoun,
North
Carolina

Adirondacks,
New York

Central Great
Plains alluvium

NSF announced a competition for
Critical Zone Observatories in 2006
($8m new money)


Largely in response to exciting new surface
Earth sciences


In partial response to the NRC BROES report
that highlighted the Critical Zone


In partial response to community pressure from
hydrologists, geochemists, geomorphologists
(e.g. CUAHSI, CZEN, NCED, others)


In partial response to proposal pressure within
Earth surface science


Run jointly by NSF Geomorphology, Geobiology
and Low T Geochemistry, and Hydrology
programs

Three Critical Zone Observatories funded ‘06


Southern Sierra Nevada (Roger Bales)


Boulder Creek (Suzanne Anderson)


Susquehanna Shale Hills (Chris Duffy)

Puerto
Rico

Delaware

Arizona


Weir

Head

Mid

Streams

Soil cores

Lysimeter nests

80 ft Drill core

1
-
D

2
-
D

3
-
D

Shale Hills catchment
: a Critical Zone observatory
designed to learn to earthcast the Critical Zone

Courtesy Henry Lin

3
-
D, integrated

SSHO: Shale Transect


Chris Duffy

Sue Brantley

Rudy Slingerland

David Eissenstat

Ken Davis

Karen Salvage

Kamni Singha

Laura Toran

Pat Reed

Eric Kirby

Tim White

Kevin Dressler

Doug Miller

Ray Fletcher

Michelle Tuttle

Paul Bierman

Peter Lichtner

Carl Steefel

SSHO Investigators

Transect Investigators

Plus, now developing,
Plynlimon, Wales!

CZEN International Sites


BigLink, Switzerland


Guadeloupe, France


Strengbach, France


Plynlimon, Wales


South Africa


France


Others

What controls the depth and chemistry of the Earth’s regolith?

Nutrients

Chemistry

of Water

Atmosphere

Landform

Evolution


What processes control
fluxes of carbon,
particulates, and reactive
gases over different
timescales?

How do biogeochemical
processes govern long
-
term sustainability of
water and soil
resources?

How do processes that
nourish ecosystems change
over human and geologic
time scales?

How do variations in and
perturbation to chemical and
physical weathering
processes impact the
Critical Zone?

Can we earthcast?

For a given lithology, can we use the
climate and the soil residence time or
exposure time to predict


….the thickness of regolith on the
landscape?


…the profiles of elements and
minerals as a function of depth to
bedrock?

What controls the depth and chemistry of the Earth’s regolith?

Craig Rasmussen: CZEN Granite Sites:

Synthesis of Regolith Weathering

2000
1500
1000
500
0
-1.0
-0.5
0.0
0.5
1.0


Na
Depth (cm)
420
511
585
785
910
1040
1200
1240
4200
Legend and color scheme indicate MAP


Na threshold near 1000 mm MAP
-

complete loss of Na in upper profile >1000 mm

How does basaltic regolith chemistry vary with depth
across a precipitation gradient?

Plot composed by Maya Bhatt, Penn State

-1.0
-0.8
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
0.8
1.0
700
600
500
400
300
200
100
0


475 SB
780 CA
1000 PA (diabase)
1040 DR (diabase)
1200 NC (diabase)
2500 HW
3000 PP
Depth (cm)

Ti, Na
Na Depletion Versus Regolith Depth: Basalt
SB=Siberia, CA=California, PA=Pennsylvania, DR=Davis Run, NC=North Carolina,
HW=Hawaii, PP=Philippines
Precipitation (mm/y)
What controls weathering along an

alluvial climosequence? (Masters thesis, J. Williams)

Iowa

Missouri

Arkansas

Louisiana

Illinois

Indiana

Kentucky

Tennessee

Mississippi

Alabama

Parent loess
--

roughly
constant in
composition
--

was
deposited
13ky bp

Soils developed on
Peoria loess that
contains 55%
quartz, 10% Na
-
plagioclase, 12%
K
-
feldspar, 10%
montmorillonite
(Muhs et al., 2001)

Fraction of Na depleted versus depth for all 22
pedons (Williams, 2008)

Northern Pedons

Southern Pedons

 =

fraction of Na (feldspar) that has been depleted over 13ky
compared to the parent loess composition at depth (assumes Zr
immobile)

400
300
200
100
0
Depth (cm)
-0.6
-0.4
-0.2
0.0
0.2
Pedons 12-22
τ
Zr, Na
400
300
200
100
0
Depth (cm)
-0.6
-0.4
-0.2
0.0
0.2
Pedons 1-11
τ
Zr, Na
1
,
,
,
,
,

=
w
i
p
i
p
j
w
j
j
i
C
C
C
C

Plot of ln (rate constant term) versus 1/T (Arrhenius plot)

Apparent activation energy from loess data = 95 kJ/mol
±

24


Average activation energy measured in laboratory = 65 kJ/mol
±

10

This observation implies that we can use laboratory rate constants
to predict weathering using reactive transport codes

Godderis, Schott,
Williams, and Brantley, in
prep.

Observed vs. simulated mineral profiles:

10ky weathering of loess at one pedon

using GCM outputs, laboratory dissolution rates,

and literature BET surface area


albite

K
-
feldspar

kaolinite

dolomite

Ca
-
Mont

Crosses =
model
predictions;
Red symbols

= data

Reactive
transport
code


WITCH
(Yves
Godderis)

Godderis, Schott, Williams, Brantley, in prep.

Criteria to become a CZEN site


Data available for water and soils down to
bedrock


Willingness to share data


Willingness to open the site to other
investigators


Interest in answering questions that can
only be answered with a network of sites

Table 1. Minimum Information to be Submitted from CZEN Sites

Site information (as available)
: Digital topography (and derived information
such as slope and curvature); Digital geology; Digital soil; Landform type;
Landform position, Parent material type (e.g., alluvial, bedrock), Latitude,
Longitude, Description of drainage characteristics, Slope, Aspect, Land use
description, Elevation, Geology.

Meteorological characteristics
: Daily, monthly and mean annual
temperature, precipitation, and potential evapotranspiration.

Regolith characterization
: Bedrock chemistry and mineralogy; Soil and
saprolite bulk density, Soil chemistry (as function of depth to bedrock), Soil
mineralogy (as function of depth to bedrock), Loss on ignition (if applicable),
Soil profile description, Landform age or soil production rates, Depth to
bedrock, Analysis company (if applicable for chemical analysis); Analysis
technique (for chemistry and mineralogy); Date of analysis; Sample
preparation (size separation, drying, ashed or unashed); Grain size
analyzed


To answer CZ questions requires
shared data


We have a great variety of data types that
vary with space and time


We need to have some measurements
that are made at all sites =
core data


We will have some measurements that are
more specialized and that will not be made
at all sites =
specialized data


CZEN has drafted an ontology that describes the structure of the data,
and it has been posted for comments

http://www.czen.org/content/critical
-
zone
-
ontology

http://www.czen.org

Data Infrastructure for CZ Science


The CZOs must share data after a two year
embargo period


Only moderate funding was included in each
CZO proposal to place data onto the web


Xianzeng Niu is working with the SSHO CZO to
organize geochemical data (see poster)


This database will be placed onto the web, but
ultimately stored with EarthChem (with Kerstin
Lehnert, Columbia U.)


We are augmenting geochemical CZO data with
data from other sites and legacy data


Geochemical kinetic data is also being compiled
as EarthKin

CZEN is a network of


Sites (network of field sites)


Ideas (network of model development)


Tools (network of tools tested on sites
and cybertools for using data)


People (network of international
scientists and students)


Claire Hoff
, U. of New Hampshire, Calcium leaching dynamics, Hasselt
University, Belgium


Heather Buss
, USGS Postdoctoral Fellow, Guadeloupe and Puerto Rico.


Heidi Albrecht
, Penn State U., Frasassi Cave, Italy.


Julie Pett
-
Ridge
, Cornell U., Oxford U., UK


Mark Waldrop
, USGS Postdoctoral Fellow, Lancaster U., England.


Sarah Hayes
, U. of Arizona, Swiss Federal Institute of Technology.


Simon Mudd
, Vanderbilt U., Oxford U., UK


Susan Crow
, Purdue U., Queen’s University, Belfast, Ireland.


Susan Riggins
, U. of Colorado
-
Boulder, British Geological Survey.

CZEN International Student Scholars

received NSF
funding to work in Europe in 2006/07

Current ongoing competition for U.S. students to
receive funding to work in Europe in 09/10 as part of
the CZO network

U.S. students also were funded to attend the
SoilCritZone meeting in Crete in Sept 2008

www.czen.org


Social networking site for Critical Zone scientists


Content management system


566 registered users


Growing at a rate of about 4/day


500 pages


33 groups including international groups


14 post types are available


Biggest problem: teaching geochemists how to
use a content management system!


Fundamental
Critical Zone
Science

CZGugle

(cybertools

for CZ
)

CZEN.org

(social networking,

data management)

EarthChem

EarthKin

(databases)

CZEN

(field sites)

Fundamental
Critical Zone
Science

USDA

EPA

NASA

DOE

NSF

EAR

BIO

The U.S. funding
perspective

If CZ scientists build the science…the funding will come