1. Earth Sciences at DUSEL: Ideas and Progress to Date Eric Sonnenthal & Brian McPherson

2. Earth Science Working Groups Coupled Processes (Hydrology, Geochemistry, Petrology) Rock Mechanics and Geophysics Note: Engineering is an integral of Earth Sciences

3. Progress and Continuing Discussion Participants have generally agreed on the unique attributes of DUSEL for Earth Sciences: Unprecedented experiments covering a wide range of spatial and temporal scales Transparent Earth: Visualization, probing the Earth in 3-D Life in “extreme environments, ancient life” Participants have not agreed on: “Societal benefits” (resources, waste management, industry needs) vs “Fundamental science and engineering” “Hard rock” vs “Soft rock” Participants need to define still: Why go deep - Specific criteria for experiments unique to DUSEL (depth - fluid pressure, temperature, stress, rock characteristics) Infrastructure needs for experiments, compatibilities, etc.

4. Question: What’s the major benefit to Earth Science of “going underground”? One Typical Approach to Subsurface Investigations: Use drill-hole data with computer model simulations Data collected at bottom of borehole. -4000 -2000 SL 2000 Elevation (m) Vertical Exaggeration x 16 Salt Creek Anticline Black Hills Powder River Basin, Wyoming Oil or Gas Well

5. Courtesy: URL at Atomic Energy of Canada Ltd Proposed New Approach: Develop a US laboratory and observatory underground, inside the earth. Much like surgery permits a physician to examine internal bones and organs recognized on X-rays or CAT scans, NUSL will be a fully instrumented, dedicated laboratory and observatory for scientists and engineers to examine Earth’s interior.

6. Surface laboratories for core, water, gas, and microbial analyses, experiments, and archives From NSF EarthLab Report

7. Deep Flow and Paleoclimate Laboratory and Observatory From NSF EarthLab Report

8. Induced Fracture and Deformation Processes Laboratory From NSF EarthLab Report

9. Ultradeep Life and Biogeochemistry Observatory From NSF EarthLab Report

10. Deep Coupled Processes Laboratory: study coupling among thermal, mechanical, hydrological, chemical, and biological processes in the subsurface (injection and transport experiments at several different depths along highly instrumented and well-characterized fracture/matrix zones) From NSF EarthLab Report

11. Priority Attributes of DUSEL for Earth Science and Engineering 1.Long-term access to large (~20+ km3) volume of subsurface in which geological features are well characterized in three dimensions, including appropriately placed sensing equipment. 2.Ability to access this environment through selective/ choice placement of drill holes, underground workings, laboratories, or observatories. Accessed host rock should reach temperatures of 120°C and waterfilled fracture systems. 3.Ability to modify geochemical characteristics of this environment by introduction of materials into holes or workings. At least one fracture zone should be accessed by multiple holes that are instrumented with an array of samplers for transport studies. 4.If an existing mine is chosen as the DUSEL site, complete access to entire archive of existing data and samples.

12. EARTH SCIENCE AND ENGINEERING CRITERIA FOR DUSEL SITE Diverse chemical and physical environments, including: Variety of hydrologic environments, such as highly permeable, near-surface soils and alluvium vs. deeper, low- permeability crystalline rocks. Variety in groundwater compositions, such as high vs. low salinity, pH, and dissolved gas concentrations. Variety of structural environments, especially density and orientation of faults and fractures. Variety of geochemical environments, especially in concentration of reduced minerals (e.g., sulfides) vs. oxidized minerals (e.g., hematite).

13. Progress Made During Berkeley and Blacksburg Workshops Starting from previous studies and workshops, the scientific community is actively working on: Identification of Major Themes Identify syntheses that make sense for the specialists, but also resonate with other scientists and fascinate the non-scientists Working groups have formed for this task: Coupled processes, rock mechanics and tectonics, geo- microbiology and applications Prioritization What are the most pressing questions to answer deep underground?

14. “Ever Changing Earth” Dynamic, Coupled processes Conditions for Life Progress Made During Berkeley and Blacksburg Workshops Some Major Themes: Conditions for Life Limits Metabolism/ Energy source Evolution The “Ever Changing Earth” Behavior of rock and fluids at depth. Coupled processes in inhomogeneous media: mass, momentum,energy flow Spatial and temporal scaling “laws” The structure and the evolution of the earth Observing from inside out: Core/mantle/crust/mountain Dynamics: earthquakes The concentration of ore deposits Climate change Paleo-climate ? Ancient sequestered water Clouds “Transparent Earth” : Resources Origin & Discovery

15. Progress Made During Berkeley and Blacksburg Workshops One Approach: Evaluate DUSEL in different contexts (1) An “Observatory” (2) An “Active Processes Laboratory”

16. 1. What are the limits of conditions for microbial life? 2. Can we increase our fundamental knowledge of the earth and its dynamic processes? Observe Earth from the inside… 3. Can we improve resolution, using observations at multiple-scales and at ranges of depths, of the couplings among thermal, hydrologic, chemical and mechanical (deformation) processes? (natural observatory context) As an “observatory,” some major science questions include: Progress Made During Berkeley and Blacksburg Workshops

17. 1.How do Mass, Momentum, and Energy transfer and transform in fractured media? (carry out THMCB Experiments) 2. How may we image and scale in fractured media? 3.How may we engineer ultra-deep and large excavations? 4.How may we better understand cloud processes to improve climate prediction? As an “active laboratory,” some major science questions include: Examples –Ore formation, characterization and recovery –Heat extraction (geothermal reservoirs) –Fracture and fault deformation and flow –Mineral precipitation and dissolution

18. Progress Made During Berkeley and Blacksburg Workshops Experiment Requirements and Infrastructure Matrix

19. Example: Drift Scale Test at Yucca Mountain Purpose of the test is to evaluate coupled thermal, hydrological, mechanical and chemical processes surrounding the potential repository Dimensions: ~ 50 meters long by 5 meters in diameter Electric heaters activated Dec. 1997, turned off Jan. 2002 Maximum drift wall temperature reached ~ 200°C Water, gas, and rock samples collected from boreholes for geochemical and isotopic studies Reaction-transport modeling performed prior to and during test (examples on following slides)

20. Water-Gas-Rock and Fracture-Matrix Interaction of Heat and Mass Water-Gas-Rock Interaction: Mineral dissolution and precipitation Changes in fluid chemistry as a result of transport/mixing, boiling/evaporation, mineral-water-gas reactions Reaction rates in fractures related to wetted surface area Fracture-Matrix Interaction: Advection and diffusion across fracture- matrix interface Also related to wetted surface area

21. Measured and Modeled CO 2 Over Time

22. Calcite Precipitation-Dissolution and 14 C Evolution Calcite precipitation in fractures above heaters owing to boiling of water draining in fractures (reflux zone) Calcite dissolution occurs in drainage and condensation zones 14 C strongly lowered in CO 2 due to calcite dissolution and addition of “dead carbon”

23. Considerations for Boulder Workshop De Define rationale and requirements for depth - Pressure, temperature, stress, chemistry Plot showing depth-property ranges for experiments comparable to plots shown for physics experiments Define rationale and requirements for rock type and characteristics Infrastructure needs for experiments