Near-surface techniques play a vital role in the preservation of shallow groundwater sources and supply critical information on any major vertical migrationThe movement of fluids in reservoir rocks of injected CO2Carbon dioxide. Characterisation of the near-surface environment begins during site selection with assessing any sensitive environmental and cultural features, e.g. wetlands, floodplains, significant habitats, groundwater, soil and other resources, land use, archaeological sites, human populations, and infrastructure. The exact elements will be specific to the local requirements.
The surface and shallow subsurface are more accessible than the deep subsurface at lower cost. The residence time of CO2Carbon dioxide is longer in the shallow subsurface than in the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) above the leak, increasing the probability of detecting the leak.
Comparable to the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%), there are numerous sources of near surface CO2Carbon dioxide emissions, such as soil microbes and vegetation; in-situ remediation of oil spills produces large amounts of CO2Carbon dioxide. The soil gas system is complex and affected by factors, such as moisture content, temperature, nutrients, and barometric pressure that vary daily, seasonally and in complex patterns. Leaking CO2Carbon dioxide may be found in the soil gas as very localised occurrence around the leakage(in CO2Carbon dioxide storage) The escape of injected fluid from the storage formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it to the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) or water column point, although it is possible that a build-up in the vadose zoneNear surface layer of aeration above the water table (where ambient air infiltrates soil) results in leakage(in CO2Carbon dioxide storage) The escape of injected fluid from the storage formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it to the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) or water column at a topographic low point that is distant from the actual leakage(in CO2Carbon dioxide storage) The escape of injected fluid from the storage formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it to the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) or water column point. Groundwater systems may be dynamic, responding to recharge and dischargeThe amount of water issuing from a spring or in a stream that passes a specific point in a given period of time.
CO2Carbon dioxide leakage(in CO2Carbon dioxide storage) The escape of injected fluid from the storage formationA body of rock of considerable extent with distinctive characteristics that allow geologists to map, describe, and name it to the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) or water column from a storage(CO2Carbon dioxide) A process for retaining captured CO2Carbon dioxide, so that it does not reach the atmosphereThe layer of gases surrounding the earth; the gases are mainly nitrogen (78%) and oxygen (around 21%) reservoirA subsurface body of rock with sufficient porosityMeasure for the amount of pore spaceSpace between rock or sediment grains that can contain fluids in a rock and permeabilityAbility to flow or transmit fluids through a porous solid such as rock to store and transmit fluids may create CO2Carbon dioxide fluxes from the surface that may be difficult to distinguish from background CO2Carbon dioxide fluxes. The magnitude of CO2Carbon dioxide seepage fluxes depends on a variety of factors, such as the mechanism of emission (e.g. focused CO2Carbon dioxide flow along a near-surface fault(geology) A surface at which strata are no longer continuous, but are found displaced or more diffuse emission through sediments), wind and density-driven atmospheric dispersion. Hence, it is extremely important to record baseline measurements for a sufficiently long period of time before the CO2Carbon dioxide injectionThe process of using pressure to force fluids down wells begins. Anomalous surface CO2Carbon dioxide fluxes may be detected using several proven and readily available techniques.