Geologic perspective for carbon sequestration by woody biomass burial

Carbon sequestration by Woody Biomass Burial (WBB) leverages carbon capture through natural photosynthesis, followed the isolation of dead or fallen wood in a relatively shallow Underground Wood Vault (UWV). Long-term geologic containment, including any greenhouse gas decomposition products, depends on careful selection UWV location and depth. To achieve durability 100 y, an initially low-moisture should be built as follows: (a) low-permeability, high-plasticity clays with hydraulic conductivity ≤10 −9 m/s, vertical/lateral separation distance ≥1 m from nearest aquifer; (b) residual compaction voids at least partially filled, loose, smectite-rich clay; (c) capped ≥2 clay compacted to <5 × 10 m/s; (d) restricted locations where 50-y seismic Peak Ground Acceleration (PGA) is ≤9% g (8.8 −1 m/s 2 ). A low-PGA location, larger cap confinement thicknesses and/or lower conductivity, capable approaching 500–1000 y more.