Iceland Kinematics From InSAR

Large-scale ground deformation in Iceland is dominated by extensional plate-boundary deformation, where the Mid-Atlantic Ridge crosses island, and uplift due to glacial isostatic adjustment (GIA) from thinning retreat of glaciers. While this mostly steady over multiple years, it modulated smaller-scale transient associated with, for example, earthquakes, volcanic unrest, geothermal exploitation. Here, we combine countrywide Sentinel-1 interferometric synthetic aperture radar (InSAR) data (from six tracks) 2015 2021 with continuous Global Navigation Satellite System observations produce time series displacements across Iceland. The InSAR results were improved a two-step tropospheric mitigation procedure, using (a) global atmospheric models reduce long-wavelength topography-correlated signals, (b) modeling stochastic properties residual troposphere. Our significantly improve upon earlier results, which based on stacking, as use more data, better weighting, advanced corrections instead just velocities. We fuse three ascending descending track estimate maps East Up velocities, clearly show large-scale extension GIA deformation. Using revised plate-spreading models, these new velocity maps, remove analyze remaining deformations. demonstrate importance mitigating signals solving not processes are present.