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The Susquehanna/Shale Hills Critical Zone Observatory

A National Science Foundation Division of Earth Sciences Proposal

Submitted by The Pennsylvania State University PI: Christopher Duffy1. Co-PIs: Susan Brantley1, Rudy Slingerland1, David Eissenstat1, Jason Kaye1, Eric Kirby1, Henry Lin1, Douglas Miller1, Patrick Reed1, Karen Salvage2, Kamini Singha1, Laura Toran3. Senior Personnel: Kevin Dressler1, Tim White1, Ray Fletcher1, Rich April6, Ryan Mathur7, Teferi Tsegaye8, Dave Harbor9,Larry McKay10, Steve Driese11, Hernan Santos12. Participants: Peter Lichtner4 , Carl Steefel5 , Marty Goldhaber13 , Michelle Tuttle13 , Thorsten Wagener1 . Affiliation : 1 Penn State University, 2 State University of New York Binghamton, 3 Temple University, 4 Los Alamos Nat. Laboratory, 5 Lawrence Berkeley National Laboratory, 6 Colgate University, 7 Juniata College, 8 Alabama A&M, 9 Washington & Lee, 10 Univ. of TN, 11 Baylor University, 12 U. Puerto Rico-Mayaguez, 13 US Geological Survey.

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1.0 INTRODUCTION The surface of the earth comprises a weathering engine or mill that solubilizes and disaggregates rock to form regolith. The rates and mechanisms of regolith formation contribute to such important processes as nutrient cycling, carbon sequestration, soil horizonation, erosion, and acid rain mitigation. Over the long term, the rates of weathering and erosion combine to control the evolution of landscapes and help to define the access, rates of motion, and time scales of water and energy within the Critical Zone (CZ). We must understand the processes and multiple feedback loops that control regolith formation in order to predict how the CZ will change in response to anthropogenic and climate perturbation. Here we propose a Critical Zone Observatory dedicated to develop this understanding. This proposal brings together two active consortia of scientists, one formed to design and implement the Susquehanna River Basin Hydrologic Observing System (SRBHOS) (www.srbhos.psu.edu), and the other formed to advance the Critical Zone Exploration Network (CZEN) (www.czen.org). The proposal takes advantage of an Environmental Molecular Sciences Institute (NSF Center for Environmental Kinetics Analysis, CEKA) at Penn State, for analysis and modeling of geochemistry in environmental systems. This research will integrate informatics and basin prediction efforts currently funded by NSF and EPA. Finally, we propose a collaborative effort with educational partners for a series of less-intensive CZOs on shale sites along climatological and lithologic gradients.

Research Overview: The purpose of this observatory and associated interdisciplinary research is to quantitatively predict the creation, evolution, and structure of regolith as a function of the geochemical, hydrologic, biologic, and geomorphologic processes operating in a temperate, forested landscape. By creating an interdisciplinary team working collaboratively in one observatory we aim to advance methods for characterizing regolith, to provide a theoretical basis for predicting the distribution and properties of regolith, and to theoretically and experimentally study the impacts of regolith on fluid pathways, flow rates, and residence times. Our research testbed, the focus of National Science Foundation-supported research since the 1970s [1-3], has comprehensive datasets on distributed water budgets (1970-75), has served as a model testbed for hydrological response(1998-present), and will be augmented here by new geochemical, geomorphological, ecological, lidar, and soils datasets, all available to the research community.

Our proposed CZ observatory is a forested, small, temperate-climate catchment in central Pennsylvania (hereafter termed the Susquehanna/Shale Hills Observatory or SSHO) in which the regolith is developing upon homogeneous shale. Shale Hills represents an opportunity to investigate the rates and mechanisms of saprolite and soil formation on a relatively simple but ubiquitous bedrock lithology that has been documented to be important in determining global fluxes of C, P, and platinum–group elements worldwide [4, 5]. Furthermore, the regolith at the SSHO has experienced at least two potentially significant perturbations in the geologically recent past: a climatic perturbation from peri-glacial to modern conditions, and a biologic perturbation from anthropogenic clearing of forests during colonial occupation. The magnitude of these perturbations and their influence on regolith generation afford an opportunity to assess the time scales of response of soil production to both long-term climate change and human activity.

We propose to test the following overarching hypotheses within the SSHO: Hypothesis 1: The thickness of regolith in the Shale Hills watershed can be predicted from theoretical models of regolith formation based on intensive observations of cosmogenic exposure ages, biological factors, aeolian inputs to soils, biogeochemical reactions, and sediment and water transport and chemistry. Hypothesis 2: When compared to similar but less intensive observations for watersheds chosen along environmental gradients, the observed and predicted rates of regolith formation at Shale Hills provides the basis for quantification of hydrologic and hydrochemical prediction as well as identification of storage reservoirs and preferential pathways in shale-dominated landscapes.

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The current Shale Hills soil moisture monitoring network [6] and the research areas that the watershed supports.

Shale Hills Catchment. Shale Hills is located near the University Park campus. The average local relief is 100 feet from the valley floor to the ridge top, and the average channel gradient is 4.5% [1]. Rose Hill Formation Shale (Clinton group) underlies the entire study area. This 700-foot-thick Silurian-age formation consists of olive-pink, grayish-buff shales with a few interbedded limestones [1]. The shale, consisting of 25% quartz, 70 % mica-smectite, < 8% kaolinite, < 4 % chlorite-vermiculite and 1% feldspar, generally shows moderate to slight weathering. The soil depth in the watershed averages 1.4 m and consists of colluvium or residuum with pH ∼6.7 [6]. Soil erosion rates characteristic of the Appalachian mountain region range from 5-30 m/million years with northern shale units (e.g. the SSHO) near the lower limit ([7] and Biermann, P., pers. comm.). Deciduous trees (maple, oak, and beech) cover the slopes; evergreen trees (hemlock and pine) are present in the valley [6]. The mean aspect of the north slopes is 18°, and the south slope is 16°. Early hydrologic experimentation at the SSHO involved exploration of the effect of antecedent moisture on flood peaks [1], and later involved new theories on dynamics of contributing-area to runoff [2, 8]. Extensive data sets are available at Shale Hills from forestry field experiments of the 1970’s, and model studies, GIS coverages, 1-m DEM, soil moisture synoptic sampling, soil mapping, streamflow monitoring and preliminary geophysics from 1996-present.

Ground-penetrating radar (GPR) cross-section, and soil types overlying the Rose Hill Formation at an upland site in the

Susquehanna/Shale Hills Observatory

2. RESEARCH APPROACH 2.1 From Process to Prediction: Creation and Evolution of Regolith in a Critical Zone Observatory. We propose to work on four questions concerning the creation and geomorphic evolution of regolith, as described below.

Question: What is the functional relationship predicting the rate of transformation of shale to regolith by (bio)geochemical and physical processes?

To answer this question, we must complete the following tasks: i) investigate fractures related to soil formation, ii) investigate one-dimensional (1D) profiles of chemistry and flow of fluids as well as mineralogy and textures of soils; iii) measure these same variables in regolith as a

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function of depth along two two-dimensional (2D) transects and integrate these observations and models into a 3D model of weathering rates in the catchment. Task 2.1.1. Analyze bedrock fractures near the bedrock-soil interface and propose a conceptual model for the bedrock to soil transformation. At outcrops of local shales, we have observed planar, subhorizontal fractures in the zone near the bedrock-soil interface. Orientation and distribution of these fractures will be measured in several outcrops of the Rose Hill shale, and the effects of roots will also be noted. Such fractures in granite have been attributed by SSHO participants Fletcher and Brantley [9] to oxidation of ferrous minerals due to diffusion of oxygen into bedrock. Oxidation of organic matter and pyrite can similarly produce fracturing and disaggregation of shales [10-16]. Fletcher and Brantley have recently extended their model for fracturing in granites to make the first quantitative chemical model explaining why soil production rates vary with regolith depth [17]. This latter model will be extended to provide the basis for a SSHO soil production model. Weakening of the bedrock by root exudates or by physical effects of root growth will be easily incorporated into the model. PIs: Brantley, Fletcher Task 2.1.2. Analyze and model the chemistry and flow of fluids as well as the mineralogy and textures of soils as a function of depth in 1D profiles at two ridgetop sites: The following entities will be measured in ridgetop sites: i) chemistry/mineralogy, porosity, and texture of rock and regolith as a function of depth, ii) chemistry and isotopic signature of water and gas in soil pores, iii) rates of porewater flow. First, we will document the mineralogical transformations in augered cores of regolith based upon elemental and X-ray diffraction analyses [18]. If the regolith is at steady state, we will be able to combine these mineralogy-depth curves with measurements of erosion rate (see question 3, below) to quantify the soil production function at the ridgetop [9, 19]. For example, preliminary measurements have documented that illite and smectite are weathering and kaolinite is forming in the SSHO: rates of these processes will be estimated with more work. Second, tensiometers and suction-cup lysimeters will be emplaced at different depths in the two sites to allow analysis of changes in porefluid chemistry due to evapotranspiration, biotic processes, mineral dissolution and precipitation. Rate of fluid flow will be estimated by implementing LiBr tracer tests [20] in collaboration with Carl Steefel (Lawrence Berkeley National Laboratory, see letter), who works as part of the Center for Environmental Kinetics Analysis (CEKA, an NSF- and DOE-funded center at PSU). Modeling of porewater chemistry will be accomplished by working with collaborator Peter Lichtner (Los Alamos National Laboratory and CEKA, see attached letter) who is updating his code, Flotran, to incorporate evapotranspiration. Modelling the ridgetop sites should be relatively simple assuming one dimensional vertical flow + evapotranspiration. If mineral reaction rates measured from fluid chemistry equal those estimated from mineralogical data, this is strong evidence for steady state weathering behavior [21] Water flow in soils at ridge tops will be conceptualized as strictly 1-D (Task 2.2.3), simplifying the weathering model at these locations. PIs: Fletcher, Brantley, Steefel, Lichtner. Task 2.1.3. Measure the flow rates, saturation, chemistry of fluid, and chemistry/mineralogy of solids in regolith along two transects: To investigate weathering reactions along 2D (hillslope) profiles, we will emplace five nests of suction-cup lysimeters, and tensiometers and we will analyze chemistry of soil cores and porewaters along i) a planar hillslope transect, and ii) a swale transect. Fluid flow along the transects will be measured by a LiBr tracer test and supported by 18O and 2H sampling. Stream and groundwaters in the SSHO will be sampled and analyzed every 2 weeks. Flow and reactive transport parameterizations will be assimilated into Flotran and PIHM (see section 2.3) for both transects. This modeling will allow the prediction of rates of weathering throughout the watershed. PIs: Brantley, Duffy, Steefel, Lichtner.

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Question: What processes control the downslope transport and erosion of regolith, and can these processes be functionally related to regolith thickness in a deterministic fashion?

To understand the feedbacks between regolith transport, thickness, and weathering in the SSHO, we need to i) characterize rates of erosion throughout the watershed and ii) relate these to distributions of hillslope topography and regolith thickness through a landscape evolution model. Task 2.1.4. Quantify rates of regolith transport and erosion: Central to the development of a model to predict regolith evolution in the SSHO is the quantitative understanding of the rates and processes of soil transport on hillslopes. To characterize erosion rates we will exploit a high resolution data set of hillslope topography and soil depth (H. Lin), densifying these observations where necessary via a combination of hand-auger, soil pits, and ground penetrating radar (see 2.4). We will measure erosion rates across a range of hillslope gradients and regolith thicknesses using the concentration of cosmogenic radionuclides from the base of the regolith [22]. These data will be compared to average sediment yields determined from volumetric surveys of sediment accumulation in swales [23], and from cosmogenic isotope concentrations in modern sediment [7]. Together, these data will provide estimates of the dependence of soil production on regolith thickness, an integral component of our geochemical modeling [9]. Moreover, understanding how the downslope transport of regolith depends on topographic characteristics such as hillslope gradient will provide the basis for a more process-based model of sediment transport (see below, and Task 2.3.1). PIs: Slingerland, Kirby, Lin Task 2.1.5. Develop and test competing models for soil transport: We propose to develop and test competing models for soil transport (linear creep, depth-dependent creep, disturbance-driven (tree-throw) transport) against the present-day distribution of soil depth, hillslope topography and erosion rate. In particular, observations of pit-and-mound topography in the watershed lead us to hypothesize that disturbance-driven transport (tree-throw -[24]) is a key component of sediment transport on hillslopes in the SSHO. We will incorporate rules that describe various soil transport processes into a new landscape evolution model (section 2.3) and test these against the distributions of topographic gradients, regolith depth, and lowering rates across the watershed. PIs: Kirby, Slingerland, & Duffy.

Question: What is the role of biologic processes in the shale weathering engine and in particular, what roles do rooting and tree-throw play?

Our hypothesis is that tree-throw [24] and the physical and chemical activity of roots strongly influence the evolution of regolith in the SSHO by: 1) moving regolith downslope; 2) mixing and chemically affecting bedrock and subsoil; 3) providing the principal pipes through the regolith mill for flow of water and solutes; and, perhaps, 4) dictating the location of channelized flow on the surface. We will deconvolve these effects with the following tasks. Task 2.1.6. Quantify the role of tree-throw in regolith transport and landscape evolution: We will couple measurements of root-length density (see Task 2.1.7) and soil strength as a function of regolith depth to develop a quantitative model for sediment transport and erosion by tree-throw that will then be incorporated into a new landscape evolution model (Task 2.3.1). We will link this model to observations of erosion across the watershed (Task 2.1.4) and with historic records of climate (primarily, frequency of strong wind storms) to scale individual transport events to long-term records of denudation. Moreover, we think it is reasonable to assume that tree-throw swales impart a roughness to the surface that plays an important role in focusing overland flow and funneling surface water to the regolith-bedrock interface. We will map these surface features at the meter scale using a total station and terrestrial LiDAR (see letter). We will then conduct a series of numerical experiments using a new landscape evolution model (Task 2.1.9 and 2.3.1) subject to varying degrees of roughness based on our surveys. The experiments will test the hypothesis that regions of simultaneous tree-throw (e.g. during severe storms) determine the

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location of first-order channels by providing pathways for flow accumulation and saturation in the near subsurface. PIs: Slingerland, Kirby. Task 2.1.7. Characterize the influence of root distribution on weathering: Trees also influence regolith formation by direct interactions with the bedrock, including physical fracturing of the rock along cleavage planes and chemical solubilization. To investigate these processes, we will dig pits into the bedrock and map root density along the pit-face (Edwards et al. submitted). In each genetic soil horizon and in cracks in the bedrock, pore water will be sampled with microlysimeters (Rhizon) in localized zones of root proliferation and in adjacent zones with few roots. Samples will be taken that include root + rock + soil for analysis using various microscopies and elemental analysis. PI: Eisenstatt, Brantley

Question: What are the processes and functional relationships interconnecting the products and throughput of the regolith mill with topography and local hydrology, and how have these

changed in response to a past climatic perturbation? Here we wish to define the numerous interactions and feedbacks between the evolving three-dimensional ground surface, the bedrock-regolith interface, regolith thickness, and the hydrologic flow field. Furthermore, the SSHO landscape has experienced repeated climate and vegetation changes from glacial to interglacial conditions as well as post-colonial land-use changes. We need to understand the extent to which the present system is a palimpsest. Our approach to obtaining both objectives is to develop a new landscape evolution model and conduct numerical experiments with it driven by fluctuating boundary conditions and calibrated against measurements of both short- and long-term rates of downslope regolith transport and isotopic measurement of long term regolith production rates. Task 2.1.9. Couple sediment transport modules to hydrologic module. The landscape model will be based on PIHM, the Penn State Integrated Hydrologic Model (see 2.3). We will add functions describing conservation of bedrock and sediment mass, multi-grain size sediment routing, channel initiation and growth, hillslope sediment flux by three-throw, rilling after fires, gravity slides, and regolith-generating functions. This model will differ from present models such as SIBERIA [25], PRECIPTON [26], DRAINAL [27], Detachment-limited model [28], GOLEM [29], CASCADE [30], CAESAR [31], ZSCAPE [32], CHILD [33], and LAPSUS (LandscApe ProcesS modelling at mUlti-dimensions and scaleS) [34] by containing full treatments of regolith hydrology and weathering rules, and will describe the evolution of ground and bedrock surfaces. PI: Slingerland, Duffy, and Kirby

Task 2.1.10. Explore the response of regolith and hydrology to perturbations away from steady-state. Simultaneously with development and implementation of the model, we will explore the question of how climatic and anthropogenic perturbations impact the critical zone within the SSHO. If regolith production approximately balances erosion in the watershed, the present-day distribution of regolith represents a steady-state thickness developed subsequent to the shift from periglacial to temperate climates during retreat of the Laurentide ice sheet in the late Pleistocene. We will test this hypothesis using a combination of stratigraphic studies of sediment accumulation in hollows [23], cosmogenic isotope concentrations from in-situ samples of weathered bedrock [35], and numerical experiments using the landscape evolution model. Stratigraphic studies provide average sediment flux estimates across convergent portions of the watershed, while cosmogenics provide a bulk measure of the rates of conversion of bedrock to regolith. Together they will provide a means to empirically define the functional feedbacks between erosion, regolith thickness, and regolith production that can be tested against numerical experiments. We also recognize that during other climate states it is likely that downslope mass flux was abetted, if not dominated by rilling after forest fires, regolith creep, gelifluction, and slurry flow. We will explore this during stratigraphic investigation, geophysical studies, and modeling (Tasks 2.1.1, 2.2.3, 2.3.1). The above hypothesis will be false if post-colonial land-use

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changes have had a major impact on regolith thickness and soil erosion rate in the Susquehanna/Shale Hills Observatory. Recent work in the lower Susquehanna watershed suggests that rapid sediment accumulation behind low-head dams may be in part driven by early agricultural practices. However, because impounded floodplains serve to integrate sediment loss from all upland hillslopes, little is known about how much erosion was accomplished during and subsequent to initial removal of virgin forests. Our stratigraphic studies will be designed to test for this; if we observe a large pulse of post-colonial sediment in hollows and/or immature soils on hillslopes, we will seek to quantify the magnitude of erosion. Moreover, an understanding of the response of regolith in the observatory to this event will provide a key test of our coupled landscape-regolith evolution models. PI: Kirby, Slingerland, Singha, and Duffy.

2.2 From Form to Function: Identification and Modeling of Hydrologic Pathways and Fluxes within the Critical Zone Elucidating the generation of storage geometry and the intrinsic architecture of surface and subsurface flow paths within the regolith, represents a fundamental step for making progress on predictive models within the SSHO. We know that the hydrology within the regolith operates over a wide range of time scales from geologic, to hydroclimatic, ecological, and anthropogenic. The experimental and theoretical approach in this component of the research has 3 goals: to build upon and extend the Real-Time Hydrologic Monitoring Network (RTH_NET, EAR IF-0418798, http://www.engr.psu.edu/rth_net/) for open-access to all data, develop a comprehensive hydrophysical database in support of modeling, and to advance a community modeling approach based the Penn State Integrated Hydrologic Model (PIHM). The research will address 4 research questions that intersect those proposed in section 2.1.

Question: What is the relative “age” and “residence time” of all waters within the SSHO, and how does this relate to the space-time patterns of regolith, vegetation, soil water, and

groundwater ? The problem of identifying sources of water and mechanisms of hydrologic response in watersheds is a function of the atmospheric forcing, the “pathways” of water, and the physical, chemical and biological processes along the path. The method of hydrograph separation into flow components [36-38], and the notion of pathways of water fluxes are conceptually related, but no complete theory presently exists capable of resolving 4-D dynamic routes and rates that water takes on the journey from atmosphere to stream. The issues of spatial variability of regolith depth, soil, and vegetation properties and the temporal variations of forcing and response are central to this question. This research element will proceed on two fronts: Task 2.2.1. Explore “Age” and “Residence Time” with Intensively Sampled Environmental Tracer Experiment: A new liquid-water laser isotope instrument has recently become available (www.lgrinc.com) for fast and accurate sampling of 18

O /16

O and D / H ratios, which is capable of more than 400 samples per day. We propose to conduct detailed synoptic sampling of precipitation, soil, groundwater, and stream sampling on a monthly basis at Shale Hills during years 1-5. The synoptic survey will select ~30 sample sites from the extensive soil monitoring network already deployed by Lin (Figure 1) and from the lysimeter sites (Task 2.1). Each site will be sampled above and below the water table. Each isotope sample location will be collocated and with soil moisture, temperature and groundwater level observations. Additionally, higher resolution time samples (~15 minute) will be collected to resolve episodic response by installing automatic samplers for precipitation (1 site), soil water (2), groundwater (2) and streamflow (1) with daily and/or variable sampling for isotopes based on rainfall or flow intensity using ISCO samplers. We have initiated discussions with the Hydrology Section of the IAEA (International Atomic Energy Agency), who are completing testing of this instrument for possible deployment worldwide under the GNIP (Global Network for Isotopes in Precipitation) and GNIR (Global Network for Isotopes in Rivers). We propose to make Shale Hills an official IAEA-WMO (World

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Meteorological Organization) GNIP North American site for at least the duration of this research effort. See IAEA letter of support for this research. PI: Duffy, Salvage, Reed, Lin and Dressler Task 2.2.2. Develop a Theory for Age and Renewal of Water: Streamflow is a mixture of many waters with complex signatures from the atmosphere, vegetation, soil, bedrock, groundwater and upstream channel processes. By theoretically defining the “age” of an arbitrary parcel of water in terms of an initial concentration in any sub-domain of the watershed, and the “residence time” as the evolving concentration leaving the sub-domain, an approximate theory for tracer “age concentration” can be evaluated. This idea was introduced in a classical paper by Bolin and Rhode [39] for steady-state atmospheric mixing of environmental tracers, and subsequently extended by the ocean and limnological communities to include more complex mixing and chemical reactions [40, 41]. A recent extension to transient hydrodynamics was proposed by Delhez et al [42]. The idea is to define the “age” distribution function for an arbitrary parcel of water with concentration c

!(t, x," ) of age ! as:

a! (t, x," ) =1

c! (t, x," )"c! (t, x," )d"

0

#

$

where c!(t, x) is the mean concentration of finite volume parcel ! . The integral is defined as the

“age concentration” and thus !"

(t, x,# ) = a"

(t, x,# ) c"

(t, x,# ) . These definitions allow derivation of a new equation in the form of the usual advection-dispersion equation for the age concentration !

"(t, x,# ) . Direct numerical solution for simulated age and residence time of the parcel is then

possible [42] . To our knowledge no such theory presently exists for spatially distributed, coupled watershed processes. This research will attempt to develop a spatially-distributed numerical model for age and residence time within the PIHM finite-volume framework. We will validate the model using the stable isotope study described above. This new theory will allow us to: perform hydrograph separation using a quantitative, physically-based method; to interpret episodic, seasonal, and longer term environmental tracer responses in complex flow systems; and to predict the watershed response to complex signatures from the atmosphere, vegetation, soil, bedrock, groundwater at the SSHO. PIs: Duffy, Salvage

Question: Can geophysical methods (co-located with hydrologic, isotopic, soil and ecological measurements) allow identification of preferential pathways and threshold behavior in

watershed response? We will use differential resistivity (ER), ground-penetrating radar (GPR), and time-domain reflectometry (TDR) to locate space-time preferential pathways, key to the movement of fluids and the formation of regolith. Geophysical techniques in combination with co-located subsurface measurements will address the following tasks: i) investigation of the shale bedrock-saprolite interface and the depth of regolith in the catchment; ii) measurement of spatial and temporal variation in flow and saturation in the subsurface with the goal of identifying preferential pathways and threshold behavior during precipitation and identification of units with similar flow behavior in coordination with research teams pursuing both Hypotheses 1 and 2. The design of this experiment is based on preliminary GPR surveys (Figure 1) carried out by PI Lin. Task 2.2.3. Image depth to bedrock and changes in soil moisture along 2D transect and 3D grids with a suite of hydrogeophysical tools. Remnant structure of the original bedrock exists in many saprolites, which provides horizontal pathways for storm flow. In areas with steep slopes, thin soils, and matrix hydraulic conductivities above the maximum rainfall intensity, water moves vertically to depth (as matrix or preferential flow), perches at the soil-bedrock or an impeding layer at depth, and then moves laterally along the lower portion of the profile [43-45]. The bedrock surface in this case is the main pathway for mobile transient saturated flow during events; mapping depth to bedrock is important. We intend to use two methods to provide

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continuous coverage of the terrain: ER and GPR. TDR, water level, and specific conductance data as well as depth-to-bedrock measurements will be used to corroborate the geophysical signals. Our geophysical workplan includes both spatial and temporal coverage. Spatial monitoring will be accomplished using cross sections on the ridge, the hillslope, and the catchment (co-located with the weathering and hydropedology studies) using both ER and GPR as a cross check for depth to bedrock measurements. PIs: Singha, Toran, Lin Task 2.2.4. Geophysical measurement of spatial and temporal variation in flow and saturation for identifying preferential pathways and threshold behavior during precipitation and identification of units with similar flow behavior—as a basis for constraining areas with similar weathering rates. At many sites, the flow of water is dependent not only on spatial heterogeneity described above, but also on temporally controlled processes. An example of this would be a critical precipitation threshold at which point preferential flowpaths connect to allow fluid movement. Data in the hillslope hydrology literature suggest that precipitation thresholds for subsurface stormwater generation may be a common phenomena [44, 46-48]. The relation of zones of saturation to micro-topography, tree-throw pits, soil heterogeneity, locally perched water tables, and preferential flow paths are examples of “discrete” behavior. Geophysical transects will be done along the planar hillslope and swale described in Task 2.1.3. Our initial field ER studies will consider 2D cross-sections along the hillslope over the scale of 10s of meters, using an array of approximately 100 electrodes to be deployed at 1m spacing along the surface. These data will be collected continuously for one month at a time on a seasonal basis, with each new dataset generated every 15 minutes using an automated, autonomous data acquisition system. These resistivity inversions will be used to locate preferential pathways at the large scale, including flow that has been characterized between the A and B soil horizons and between soil-bedrock interfaces. Next, smaller-scale features will be imaged with 3D grids at the scale of approximately 1 m, with the goal to image features on the order of 10s of centimeters with the same time sampling. Data will be collected at three locations along multiple hillslopes, including an upgradient dry location, a downgradient wet location, and an intermediary point. These locations will be co-located with 3D GPR surveys and the real-time hydrologic and hydropedologic monitoring stations. From this data set, we intend to: 1) determine the interconnection of lateral preferential flow paths at the submeter to meter scale, 2) estimate the relative travel time of fluids in various pathways since rainfall events, and 3) monitor the development of threshold behavior associated with the filling of depressions in the bedrock surface, where subsurface flow initiates according to the “fill-and-spill” hypothesis proposed in [46]. PIs: Singha, Toran, Lin

Question: What is the role of plant transpiration and root distribution in controlling water loss to the atmosphere from different depths in the regolith and in different locations along the

hillslopes of the SSHO? Trees strongly influence patterns of water movement in the regolith and the mineralization that occurs there. Water transport to the atmosphere is primarily driven by plant transpiration, which not only depends on air temperature and atmospheric vapor pressure, but also on a range of plant characteristics, including leaf area, stomatal conductance, stem hydraulic conductivity and root distribution [52]. Species vary to the extent that deep sources of water are utilized to support transpiration, which also may vary, depending on plant location on the landscape and the soil type. During periods of drought, some species will limit transpirational loss, especially in the upper slope, while others may utilize deep sources of water [53, 54]. Thus, an understanding of the hydrologic potential of the landscape requires information on patterns of tree water use among species and at different landscape positions. Transpiration is crucial to hydrologic modeling. Task 2.2.5. Measurement of transpiration as the critical step in closing the water and energy budget. Sap flux density, a measure of whole-tree water use, will be determined using variable

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length heat dissipation probes with a heated and reference sensor near the base (approximately 2.5 m) of the north side of the trunk of eastern hemlock and white oak. Trees sampled will be along the transects described in 2.1. Methods will follow that of James et al. [55] and Meinzer et al. [56]. PIs: D. Eissenstat and H. Lin Task 2.2.6. Partitioning of deep and shallow sources of water. To assess the proportion of water from deep source, the natural abundance of 18O and 2H in the deep and near surface soil water previously determined for 2.1 and 2.3, will be used in standard mixing models will be used to assess the relative contribution of each water source. Natural abundance of water in the tree sap will be determined using standard approaches [57]. Root distribution determined in 2.1 will be used to assess tree access to deep water. Investigators: PIs: D. Eissenstat, J. Kaye and H. Lin Task 2.2.7. Install an Eddy Flux station at Shale Hills The instrumentation for a whole canopy eddy flux tower will follow the well-developed and tested recommendations of the AmeriFlux network [58, 59]. Fluxes of water vapor, momentum, and sensible heat are measured continuously via eddy covariance, and radiation sensors (hemispheric up and down solar and terrestrial components, direct and diffuse incoming solar and photosynthetically active incoming solar) will provide radiative forcing data. Fluxes will be computed in real time at the tower and made available online, and raw data will be saved and fluxes computed in post-processing mode for increased long-term accuracy [59]. PIs: K. Davis and P. Reed

Question: How do regolith forming processes contribute to development of meter-scale soil structures and a subsurface preferential flow networks, and how can these structures be

parameterized to predict hydrologic response? The goal here is to elucidate how the processes of landscape evolution and weathering lead to the formation of network-like structure in the subsurface soil of the SSHO and to quantify the complex preferential flow dynamics and threshold-like hydrologic response under varying precipitation, soil type, and initial moisture conditions. Feedbacks between soil formation and subsurface hydrologic processes are critical for understanding high spatial-temporal variability in soils and landscape water flux, and their relations to the erosion/weathering dynamics of the landscape. Subsurface network structure and its associated flux are also linked to the pattern of plant root distribution. Horizontal and vertical heterogeneity of soil types and their various properties are among the most challenging issues for predicting landscape water flux [60, 61]. However, few hydrologic models presently incorporate the detailed spatial properties in models. Park and van de Giesen [62] proposed hydrological landscape units hillslope- and soil-landscape delineations and show that these units explain up to 73% of the average soil moisture variation at the Tarawarra catchment. Precision soil-landscape mapping also provides a strong foundation for optimal monitoring design and model parameterization. Task 2.2.8. Design and implement a high-resolution soil-moisture, groundwater level measurement system. In coordination with each of the science teams, in particular Task 2.1.2-2.1.3, we will map the subsurface network-like structure in selected hillslopes at the SSHO. The collected data will be correlated with the regolith thickness distribution. Geophysical investigations (see Tasks 2.2.3-2.2.4) will be combined with real-time soil moisture monitoring to image the subsurface and its hydrologic dynamics. The liquid water isotope laser (Task 2.2.1) will also be used to evaluate the flow pathways. We will augment current RTH_NET real-time soil moisture monitoring stations throughout the SSHO using a distributed wireless network, covering all soil types and landscape features (e.g. slope, aspect, vegetation, etc.). Detailed mapping of the subsurface heterogeneity and the distribution of soil types will then facilitate the parameterization and implementation in our hydrologic modeling of the SSHO (Task 2.2.9). In combination with the wireless soil moisture monitoring stations currently under development and the geophysics (above), we plan to design a grid of shallow water wells and nested piezometers (1 x 1 m grid) in both swales and convex hillslopes at the SSHO, to capture

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highly transient water table dynamics along the hillslopes. We will closely examine the initiation of preferential flow and threshold values at the automatic real-time soil moisture and water table monitoring stations and explore their relationships with varying precipitation inputs, antecedent soil moisture contents in different seasons and within different soil types and landscape units. Water table and soil moisture fluctuations can play a critical role in the rate of weathering [63, 64] as well as the for the hydrologic model (see below). PIs: Lin, Singha, Kaye, Reed, and Duffy.

Task 2.2.9. Creating a Probabilistic Extension of the Regolith/Soils/Climate Database in Support of Hydrologic Modeling. The hydrology team will work with the geomorphology, geophysics, soils, vegetation, and atmospheric scientists (2.1-2.2) to develop a fully distributed, probabilistic characterization of regolith depth, soil macro-porous properties, vegetation biomass, and climate forcing, in order to incorporate this information into the PIHM_GIS database. At present, all relevant spatial data necessary for mean-field hydrologic modeling has been entered into a SRBHOS Geodatabase (basin-wide). The new probabilistic characterization of data fields for shale terrain will provide a basis for uncertainty analysis and sensitivity studies building on current tools developed by the SSHO PIs and collaborators [65-67]. The uncertainty and sensitivity analysis will be particularly valuable for evaluating SSHO conceptual models and guiding an evolutionary observation strategy for the SSHO [68-70]. The PIs will develop quarterly group meetings to design and implement an SSHO Adaptive Modeling and Monitoring Plan for guiding the coherent selection and assessment of long-term monitoring sites as well as specialized sites targeted for short-term scientific campaigns. The value of new information and the appropriateness of site conceptual models will be evaluated using available observations combined with PIHM simulations formulated for multiples scales and processes. Observations and simulation forecasts will be combined using statistical assimilation tools [71-74]. Physical and statistical modeling tools will provide a mechanism for sequentially assessing the value added by observables (e.g., changes in system entropy). In addition, this research element will include developing new process models for PIHM, including sediment transport, dynamic vegetation, preferential flow, and macro-pores (funded separately by NOAA & NSF). Once the PIHM and PIHM_GIS are complete for the SSHO, simulation scenarios will be developed to numerically study the role of spatial variability on the complex pathways of water within the SSHO, and the role of sub-grid variability on prediction. A preliminary mean-field model for the SSHO can be seen (www.srbhos.psu.edu). PIs: Reed, Miller Duffy, Dressler, Wagener, and Lin.

2.3 A Synthesis of Observatory Science Through Community Models The fundamental challenge of the Environmental Observatory is:

Can intensive observations of a single watershed with integrated state-of-the-art community models, lead to new physical predictions; and can the insight gained from this process be

extended to other terrain, shale lithologies and climate conditions?

Our approach to synthesis of research elements 2.1 and 2.2 will focus on this question, based on the coordination of field experiments and new process representations. A brief discussion of the community models to be used in this research follows. PIHM The Penn State Integrated Hydrologic Model and PIHM_GIS is a distributed, open-source integrated hydrologic modeling system which is being developed with support from NSF, NASA, and NOAA. At present PIHM has been tested through field implementation at the SSHO testbed for the processes of interception storage, evapotranspiration, snowmelt, overland flow, vertical unsaturated flow, 3-D saturated flow, 2-D surface flow and 1-D channel flow [76, 77].. PIHM uses a Triangular-Irregular Network (TIN) representation for watershed discretization, and formulates the governing equations using the semi-discrete finite volume method [75] using the SUNDIALS CVODE solver for systems of stiff ODE’s (ordinary differential equations). TINs are generated from the digital terrain model using the PIHM_GIS tool and the Shewchuck algorithm

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for optimal unstructured grid design. Once domain-decomposition is complete, each TIN is projected vertically from bedrock through each geologic and soil layer through the canopy to form the finite volume or prismatic elements. The stream channel cross-section is trapezoidal, or rectangular. The river network, watershed boundary, elevation contours, soil and vegetation types each represent user-constraints on the domain decomposition. That is, the domain can be generated to follow mapping classification units within the larger watershed boundaries. A preprint is available which includes the first generation SSHO model (www.srbhos.psu.edu/). Task 2.3.1. Implement Sediment Transport and Landscape Evolution in PIHM. A major task of this research is the implementation of models for sediment transport (days-to-decades) and landscape evolution (years-to-millennia) using the PIHM hydrologic framework, with model development supported by experiments described in sections 2.1-2.2. Our PIHM_GIS contains climate and landuse forcing data sets (100 years). The theoretical side has already begun with the dissertations of M. Kumar, G. Bhatt, and S. Li who are presently developing the basic 4-D flow, solute and sediment transport in PIHM under separate NSF and NOAA grants. The geomorphology team will lead the development of the landscape evolution model (section 2.1). PIs: Slingerland, Duffy and Kirby The Shale Hills watershed is currently a focus-field site for the Center for Environmental Kinetics Analysis (CEKA) at Penn State. CEKA, an NSF-DOE funded Environmental Molecular Sciences Institute directed by coPI Brantley, focusing on scaling geochemical kinetics from the molecular to the field scale. A small number of geochemical measurements have been made at the SSHO by CEKA personnel. Interaction between CEKA and the proposed CZO will serve to leverage the initiative, with one graduate student and one postdoctoral scholar from CEKA investigating geochemical reactions at SSHO. In addition, two DOE-funded CEKA collaborators, Peter Lichtner (Los Alamos National Laboratory) and Carl Steefel (Lawrence Berkeley National Laboratory) will be involved in this effort (see attached letters). Lichtner and Steefel have developed flow an reactive transport codes (FLOTRAN and CRUNCH, respectively) within the weathering environment. Both collaborators have participated in reactive transport workshops at Penn State and they are currently coadvising three PSU grad students in the Dept of Geosciences. The involvement of CEKA in this CZO effort will provide educational and research opportunities for researchers to utilize state-of-the-art reactive transport modeling. PFLOTRAN has the capability of modeling multiphase, multicomponent reactive flow and transport using a fully implicit solution technique. Parallelization is carried out using domain decomposition based on the PETSc (Parallel Extensible Toolkit for Scientific Computing) parallel libraries. PFLOTRAN can describe partially saturated porous media taking into account reactions involving aqueous and gaseous species, and minerals in isothermal or non-isothermal systems. Van Genuchten, Brooks-Corey, or other capillary functions are available for modeling two-phase air-water systems. Thermodynamic data is provided from an extensive database for minerals, aqueous complexes, and gaseous species. The code is currently supported by a DOE SciDAC II (Scientific Discovery through Advanced Computing) grant with PI Lichtner. Enhancements to the code will include an unstructured grid capability implemented in PETSc and adaptive mesh refinement, and the capability of modeling multiscale processes through a sub-grid scale approach. Lichtner and Duffy will combine elements of the subsurface chemical reactions from PFLOTRAN within PIHM. CRUNCH Steefel will work with Brantley to implement a LiBr tracer test in Shale Hills and to model the tracer transport using CRUNCH. CRUNCH is a code for simulating multicomponent, multi-dimensional reactive transport in porous media. The code is written entirely in FORTRAN 90 and incorporates into a single code most of the features previously found in the GIMRT/OS3D package (Steefel and Yabusaki, 1996; Steefel, 2001) along with many new features. Using an automatic read of a thermodynamic and kinetic database, the code can be used for reactive transport problems of arbitrary complexity and size (i.e. no a priori restriction on the number of

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species or reactions). The main features of the code include advective, dispersive, and diffusive transport in two dimensions using the global implicit (GIMRT) option or three dimensions using time-splitting and reaction (OS3D); unsaturated transport with gas-aqueous phase exchange; multicomponent aqueous complexation; kinetically-controlled mineral precipitation and dissolution; multicomponent ion exchange on multiple sites; advective transport of solid phases to simulate erosion or burial; The code uses an integrated finite volume approach currently restricted to orthogonal grids. Advective transport may be simulated with upwind or a third order TVD method when using the OS3D runtime option. 3.0 EDUCATION & OUTREACH An important component of the Susquehanna/Shale Hills CZO is our inclusion of six regional sites located on shale to enhance our understanding of shale weathering along a climatologic gradient of eastern North America described in section 2.1. Our latitudinal network of sites located on Rose Hill–equivalent shales will be anchored in north-central NY on one of the shales (Sodus, Sauquoit or Willowvale Shales) of the Clinton Group, and will be managed by Dr. Rich April, Colgate University. The Rose Hill Shale is recognizable in southern VA, although it is considerably thinner than in central PA; this second site will be managed by Dr. David Harbor, Washington and Lee University. The northern AL site will be located on the Rockwood or Red Mountain Formation, and will be managed by Dr. Teferi Tsegaye, Alabama A&M University. Here we will attempt to locate our site near an existing soil profile or weather station of the Alabama Mesonet (ALMNET), a collaboration between NASA, USDA and AB A&M for remote sensing calibration and validation of soil moisture data. The Puerto Rico site will be located on the Cretaceous El Rayo Formation and will be managed by Dr. Hernan Santos, University of Puerto Rico-Mayaguez (UPRM). Alabama A&M and UPRM are minority-serving institutions that will facilitate the involvement of under-represented groups. In PA, a Marcellus Shale site, of differing lithologic character than the Rose Hill Shale, will be managed by Dr. Ryan Mathur, Juniata College. Several sites in eastern TN will be cooperatively studied by Dr. Larry McKay, University of Tennessee, and Dr. Steve Driese, Baylor University. One REU student will be associated with each satellite site per year, for a total of six students per year or twenty-four students over four years of our study. Senior personnel at each partner institution will advise the students while members of the Penn State outreach team will coordinate their activities. The students will work on a variety of activities ranging from geochemical analyses of soil and bedrock samples to data collection and analyses from onsite instrumentation.

4.0 RESULTS FROM CURRENT & RECENT RESEARCH C. J. Duffy:, For the last 3 years Duffy has focused on developing the fully distributed, physically-based dynamical modeling code PIHM (Penn State Integrated Hydrologic Model) for multi-scale, multi-process applications suitable for a wide range of hydroclimatic settings. This research is funded by NSF:“Integrated Modeling of Precipitation-Recharge-Runoff at the River Basin Scale: The Susquehanna” (EAR-0310122, 2003-2006, $410,000); NASA: “Soil moisture & water table dynamics in ungaged runoff in mountain-front systems: Rio Grande” (ER020059, 2002-2006, $360,000); and NOAA GAPP: “Modeling Seasonal to Decadal Oscillations in Closed Basins: A 150-yr Lake- Level Reconstruction”. (NA040AR431, 2004-07, $350,000). The basic theory is developed in Duffy [78], and Qu and Duffy [77] and individual processes model components were tested and confirmed in the dissertation by Qu [76]. Three dissertations from this research are in progress: M. Kumar (“Integrated Hydroclimatic Modeling in the Wasatch-Great Salt Lake Basin”, 2007); G. Bhatt (“Multi-scale Solute Transport and Integrated Data Model for Large River Basins”, 2008); and S. Li (“A Fully Coupled Hydrology-Sediment Transport Model for Reservoir Sedimentation and Dam Removal Evaluation”, 2008). Two papers [70, 79] published in Water Resources Research develop strategies for community participation in Environmental Observatories. S. L. Brantley: NSF CHE 0431328, 9/04 – 8/09, “EMSI: Center for Environmental Kinetics Analysis (CEKA)” S.L. Brantley (PI), W.D. Burgos (Co-I), B.A. Dempsey (Co-I), P.J. Heaney

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(Co-I), J.D. Kubicki (Co-I), B.E. Logan (Co-I), C.E. Martinez (Co-I), K.M. Merz (Co-I), K.T. Mueller (Co-I), K.A. Osseo-Asare (Co-I), M. Tien (Co-I), $6.7 million. CEKA is an Environmental Molecular Sciences Institute, funded by the NSF, the U.S. Department of Energy Biological and Environmental Research Program (BER), and Penn State. DOE collaborators are from Los Alamos National Lab (Peter C. Lichtner), Lawrence Berkeley National Lab (Carl I. Steefel, Glenn A. Waychunas), and Pacific Northwest National Lab (John Zachara). Susan L. Brantley, the Director of CEKA, leads the group. Highlights of CEKA include: 1) Fall 2006, CEKA funded 18 grad and 13 REU students from 5 departments. 6 of the REUs were drawn from under-represented groups. 2) PSU grad student J. Moore works with Brantley, Lichtner, and A. White to model geochemical reactions in the Merced chronosequence, CA, using Lichtner’s code FLOTRAN. 3) Alexis Navarre works with Brantley and Steefel modeling weathering of basalt in a Costa Rican chronosequence using CrunchFlow. 4) CEKA collaborators chose the Shale Hills catchment in 2006 to be the focus of their local environmental kinetics research. Ongoing CEKA SSHO research led by Ramesh Ravella is measuring soil porewater in three lysimeter nests and in ground- and streamwater, and analysis of soil mineralogy using chemical analysis and X-ray diffraction analysis. Publications [9, 17, 80-85]. P. M. Reed: Reed’s initial NSF support for the RTH_NET initiative is an ongoing grant entitled “Technician Support for Real-Time Sensor Systems in the Penn State Experimental Forest” (EAR IF-0418798, 2004-2007, $225,000) PI Reed. Zhenxing Zhang, the Information Systems Technician, is leading the preliminary deployment and maintenance of the RTH_NET field facility’s real-time sensor and data publication systems (http://www.engr.psu.edu/rth_net/). Moreover, this proposal will leverage Duffy (PI) and Reed’s (Co-PI) NSF-project entitled “Integrated Modeling of Precipitation-Recharge-Runoff at the River Basin Scale: The Susquehanna” (EAR-0310122, 2003-2006, $410,000). Reed is advising Ph.D. student Y. Tang in his thesis project entitled Multiobjective Model Identification and Evaluation: The Susquehanna, which seeks to optimize precipitation-recharge-runoff model dimensionality, parameterization, and prediction accuracy. Publication Resulting from this Award [65, 70, 86-88]. R. R. Slingerland: NSF Award No: EAR- 04178776. Amount: $134,870. 20042006. “Processes of Channel Bifurcation in Fluvial Systems”. This research attempted to better understand the origin of bifurcations in deltaic channel systems using remotely-sensed data from 24 river-dominated deltas. The data represented a broad range of climates, sizes, and discharges, Numerical modeling experiments was used to interpret these data. Publications and Presentations Resulting from this Award [89-92]. NSF Award No.: OCE 03-05699; Amount: $193,844. 2003-2006. Title: Developing a Quantitative Understanding of Clinoform Formation. This research explores the causal relationships between clinoform attributes and the processes that create them in the Gulf of Papua by acquiring more than 6800 km of high-resolution seismic data (2300 km of surface-towed Edgetech and 4500 km of hull-mounted Knudsen) and through 52 coring stations in the study area. Publications and Presentations Resulting from this Award [89-91]. Laura Toran: NSF (EAR-0609827) Suspended sediment transport in karst, $154,641, 5/1/02 to 4/30/05. We found variations in storm response provided insight into recharge patterns in different karst systems. One PhD student and three female MS students were funded on the project. Five papers to date and 15 abstracts [93-114]. Toran and Nyquist: (NSF EAR- 0509853) Geophysical monitoring of groundwater-lake interactions, $51,080, 09/01/05 to 08/31/06. This was a one-year pilot to test the feasibility of using a new marine resistivity tool to improve mapping of groundwater discharge. The system was tested by a masters student, and a follow on proposal received multi-year funding (starting 7/1/06).

5.0 INFORMATION MANAGEMENT & CYBERINFRASTRUCTURE The Critical Zone Exploratory Network (CZEN) activities at Penn State, in collaboration with SRBHOS, and particularly the NSF supported Real Time Hydrologic Monitoring Network (RTH_NET, EAR IF-0418798) experiment at the Shale Hills watershed is a lynch-pin to our research. RTH_NET

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represents a multidisciplinary effort into real-time sensor systems that will integrate climate stations, eddy covariance flux station, sapflow sensors, and surface-layer micrometeorological network, stream gages, soil moisture profilers, and pressure transducers for monitoring groundwater levels. Real-time, internet accessible data from these sensor arrays is supporting research on interactions between the atmosphere, land surface and subsurface, and the riverine hydrologic system. RTH_NET is currently building a web portal, and a “virtual” CZEN data and information system by creating a semantic infrastructure that can be accessed through advanced data search and retrieval mechanisms. The Susquehanna/Shale Hills CZO will be part of the CZEN Data and Information system (CZEN-DIS) and will receive full support in the development, maintenance, and archival of data collected as part of their project. The Shale Hills site will advance strategies for interfacing with active networks and incorporating real-time observations into CZEN data management and access structures. We note the availability of high resolution color orthophotography and LiDAR for most of the SRB in late 2006-07 (Miller PSU, PI). The observation and model-data produced in the proposed effort will be made available through web-services developed through the CUAHSI information system and geospatial data handling tools, in cooperation with the CZEN cyberinfrastructure initiative lead by Co-PI Miller. Development of the SSHO on-line information system will be synergistically supported by nearly $1-Million in current PSU NSF observatory and cyberinfrastructure grants (RTH_NET EAR IF-0418798; Susquehanna WATERS information system node EAR-0609741and EAR-0609791; CZEN cyberinfrastructure EAR-0533644).

6.0 BROADER IMPLICATIONS AND EXPECTED OUTCOMES The proposed research will advance established research partnerships and collaborations (SRBHOS and CZEN) and will assure the critical mass and leverage necessary to sustain quality research, facilitate dissemination of data, and community models. The multidisciplinary effort will allow a new and collaborative approach to formulating hypotheses and potential scenarios for environmental change within shale landscapes; it will promote the development of new data-driven algorithms that enhance our ability to represent and predict water cycle dynamics; and will support a scientifically-based design for the future observatory’s sensor network. Addressing these issues for shale terrain will aid CZEN and SHRBOS scientists in developing strategies for assessing climate and human feedbacks across other litholgies, climate zones, as well as physiographical and ecological conditions. Regionally, the modeling tools developed in this research will contribute to the next generation water management and forecasting systems for the Susquehanna and the larger Chesapeake watershed. Software and data resources developed in this project are dedicated to the “open source” framework and will be shared through public data archives. Additionally, this research effort will exploit regional collaborations to promote undergraduate education and to recruit demographically and geographically diverse students currently underrepresented in earth and hydrologic science. Particular implications include:

• Develop a predictive understanding of the factors that control regolith generation and thickness in response to perturbations in climate and human activity, one of the largest sources of uncertainty in hydrological modeling and resource assessment.

• Shale lithologies are globally extensive: our experiment aims to improve understanding of the water/carbon dynamics in shale (a major component of the global carbon budget )

• Cyberinfrastructure will be an early and continuous investment. • Multidisciplinary and multiscale observatory protocol for data and community models

developed from this study will be widely to other landscapes and terrestrial ecosystems • Education of new generation of soil scientists, hydrologists, and geoscientists • Scientific visualization of the Shale Hills landscape-soil-hydrology-biogeochemistry for

the Smithsonian soils exhibit and the Year of Planet Earth, both in 2008.

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7.0 PLAN OF WORK Development of the Susquehanna CZO field Facility YR 1 YR 2 YR 3 YR 4 YR 5 Creation & Evolution of Regolith Task 2.1.1 Bedrock fracture study X X Task 2.1.2-3 Weathering & reaction rates experiment X X X X X Task 2.1.4-5 Regolith transport process models X X X X X Task 2.1.6-7 Tree-throw roots & weathering X X X X Task 2.1.8 Landscape evolution & hydrologic modeling X X X X Task 2.1.9 Explore steady-state regolith hypothesis X X X Education& Outreach** X X X Hydrologic Pathways & Fluxes Task 2.2.1 Hi-res. isotope experiment 18

O /16

O - D / H X X X X X Task 2.2.2 Theory for age and residence time of waters X X X X X Task 2.2.3-4 Geophysics, bedrock and pathway mapping X X X Task 2.2.5-7 Transpiration, isotope study, eddy flux X X X X Task 2.2.8 Hi-Res soil moisture & GW level experiment X X X Task 2.2.9 Probalistic database for model parameters X X X X Task 2.3.1 PIHM sediment*and landscape evolution X X X X X Community Models Publish to Web X X *funded under a separate grant, ** Education and Outreach is integrated with all tasks 8.0 PROJECT MANAGMENT Because of the complexity of the proposed research, the relationship to parallel research projects by the PI’s, and the need for continuous communication with involved consortia (SRBHOS, SEKA), we propose to form a Research Management Team (RMT) from the senior PI’s from Research Areas 2.1-2.5. Duffy and Brantley will chair and co-chair the RMT with the assistance of Dressler and White. The RMT will be responsible for assuring that the progress reports and the final technical reports are submitted after each funding period. The products of this research will include on-line visualizations of 4-D model data, historical records, real-time data, progress reports, and research papers. Spatial and temporal data will be collected for the entire period of the research and made available to the wider community through our on-line information system, that is being supported through current NSF grants to SSHO PIs (RTH_NET EAR IF-0418798; Susquehanna WATERS information system node EAR-0609741; and EAR-0609791; CZEN cyberinfrastructure EAR-0533644).

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