HR: 1340h
AN: T33A-0527    [Abstracts]
TI: Ridge Flank Crustal Systems: Potential for Permanent Sequestration of Anthropogenic Carbon Dioxide on the Juan de Fuca Plate
AU: * Goldberg, D
EM: goldberg@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory of Columbia University, Rte 9W, Palisades, NY 10964 United States
AU: Matter, J
EM: jmatter@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory of Columbia University, Rte 9W, Palisades, NY 10964 United States
AU: Takahashi, T
EM: taka@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory of Columbia University, Rte 9W, Palisades, NY 10964 United States
AU: Mutter, J C
EM: jcm@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory of Columbia University, Rte 9W, Palisades, NY 10964 United States
AB: We explore the scientific and technical potential of a deep-sea basalt aquifer on the Juan de Fuca ridge for long-term sequestration of CO₂ as a means of reducing atmosphere build-up of this greenhouse gas. The ocean crust offers two primary and explicit scientific advantages over other potential sequestration targets: (1) it has a potential geological capacity large enough to accommodate a major portion of fossil fuel CO₂ which is produced globally (~22 billion tons/yr as CO₂ or 6 Gt-C/yr); and (2) the chemical reaction of CO₂ with basalt will produce (Ca,Mg,Fe)CO₃ infilling minerals, permanently sequestering carbon in a chemically stable and non-toxic form. We present basalt dissolution rates based on laboratory and land-based field experiments; the rate of dissolution and precipitation reactions in the field environment must be evaluated by in situ experiments. Recent studies from the Integrated Ocean Drilling Program suggests that the basaltic ocean crust on eastern extent of the Juan de Fuca ridge flank offers large volumetric capacities, high permeability, sufficiently closed water-rock circulation pathways, long fluid retention times, and efficient technological options for the injection and subsequent monitoring of CO₂. Measured crustal fluid temperatures of 62-64^oC at these sites facilitate CO₂-basalt reactions. We propose to re-occupy pre-existing crustal drill holes to inject supercritical CO₂ and monitor the fate of the basement fluids using nearby semi-permanent, sealed-in instruments and samplers. Fundamentally this experiment will be a fluid tracer test using supercritical CO₂ plus conservative tracer compounds to establish the rates of the basalt-brine-CO₂ reactions, their relationship with the subsurface biology activity, and the potential for immobilizing CO₂ as non-toxic and stable Ca-Mg-Fe carbonate minerals in the ocean crust.
DE: 0463 Microbe/mineral interactions
DE: 1039 Alteration and weathering processes (3617)
DE: 1694 Instruments and techniques
DE: 3036 Ocean drilling
DE: 4832 Hydrothermal systems (0450, 1034, 3017, 3616, 8135, 8424)
SC: Tectonophysics [T]
MN: Fall Meeting 2005