Carbon capture and storage (CCS) projects may use satellite InSAR to look for surface deformation linked to injection and other processes, but the interpretation is not simple. InSAR offers wide-area, millimeter-sensitive surface measurements and a historical baseline that can be established before injection begins, which makes it a valuable part of a monitoring program. However, a detectable change at the surface does not tell an operator exactly where CO₂ is moving underground, and a flat or noisy time series does not prove that a storage complex is secure. Getting real value from the data depends on specialist interpretation.
First, establish whether an injection signal is detectable
Injection can produce a surface response, but whether it rises above background variability depends on reservoir depth, mechanics, geometry, injection history and measurement noise. Other processes, such as groundwater changes, seasonal deformation and regional subsidence, can produce signals in the same place. A monitoring plan needs an explicit detectability study before InSAR is relied on for a given site.
You can read more about SkyGeo's pre-feasibility approach for CCUS InSAR monitoring, developed with Stanford University, which combines geomechanical modeling, long-term time series analysis and background noise assessment to test whether a surface response can be detected with confidence. Detectability varies from site to site, which is why this assessment comes first.
Don't mistake a deformation pattern for a plume map
InSAR observes the displacement of radar-visible surface targets. It does not directly measure subsurface CO₂ saturation, plume edges or caprock integrity. The footprint of deformation may be broad, subtle or influenced by several geological layers, and working back to pressure or plume behavior is an inverse problem with more than one possible solution.
Interpretation therefore requires a geological model, injection records, reservoir and geomechanical information and the independent monitoring appropriate to the project. InSAR analysts should state what the data is consistent with, what assumptions were made and which questions remain open.
A non-detection must not become a safety claim
If no unusual deformation is detected, several explanations remain possible. There may be no measurable surface response, the response may be below the detection threshold, the relevant surfaces may be poorly observed, or the direction of motion may reduce line-of-sight sensitivity. The absence of an InSAR anomaly is not, on its own, evidence of no leakage or guaranteed containment.
Equally, an anomaly does not by itself mean containment has been lost. Telling a routine injection response from an integrity issue requires a wider assessment. Communications with regulators and the public should separate observation, interpretation, anomaly investigation and project-level assurance conclusions.
Why reference stability and noise matter
Apparent displacement can reflect atmospheric delays, an uncertain reference area or changes in how targets reflect radar. Seasonal behavior can overlap with an injection-related trend. A single striking image can therefore be misleading if it is read without specialist review, especially when the expected project response is small compared with background variability.
Analysts should report how the reference point was selected, the temporal sampling, confidence or uncertainty estimates, data gaps and the method used to compare pre-injection and injection-phase conditions, as these details, together with an adequate baseline and independent measurements, matter as much as the number of points on a map. You can explore the underlying research, including work on spatial monitoring of geological carbon storage, in SkyGeo's scientific papers library.
Fit InSAR into monitoring, measurement and verification
A defensible CCS program combines several evidence sources, for example seismic surveys, well integrity testing, downhole pressure and temperature, geochemical measurements, geomechanical modeling and, where suitable, surface movement data. The methods required depend on the project and the regulatory framework. InSAR is an important complementary layer of observation that adds to your monitoring capabilities, providing repeated, wide-area surface coverage that point measurements cannot. You can read more about SkyGeo's work on subsurface storage monitoring.
Reporting separates measured movement, detectability limits, possible causes, comparison with model expectations and the action required if an anomaly cannot be explained. The result is a clear, qualified recommendation for follow-up rather than a simple green or red status.
Frequently asked questions
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Not on its own. InSAR measures surface deformation where conditions allow and adds valuable wide-area evidence to a monitoring program, but containment and leakage assessment also require other forms of monitoring and a project-specific assurance framework. A quiet InSAR map alone is not proof of containment.
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Not directly. Uplift may be consistent with a subsurface pressure response, but its relationship to plume geometry is not unique and depends on geology and modeling assumptions.
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A site-specific feasibility and detectability assessment covering historical background variability, expected displacement, satellite geometry, reference stability, uncertainty and how InSAR will complement the project's other monitoring.
