A Wide-aperture Geodetic Experiment in the Divergent Oceanic Plate Boundary Zone of Iceland

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The researchers are builing upon a recently established international collaboration that includes institutions from Iceland, Switzerland, France, Japan, and the United States. The intent of the project and collaboration is to investigate the complex four-dimensional crustal deformation field associated with the divergent oceanic plate boundary zone of Iceland using a dense wide-aperture high-rate continuous GPS (CGPS) network much like the EarthScope PBO network. Goals include characterizing the complex spatial and temporal pattern of deformation in the central highlands of Iceland, the broadest segment of the global mid-ocean ridge system exposed above sea level, located between the overlapping West Volcanic Zone (WVZ) and East Volcanic Zone (EVZ). The researchers are developing new models for analysis time-dependent deformation processes, such as recovery of elastic strain at depth via plastic yielding, filling or emptying of magma chambers, viscous and elastic responses to changing surface and subsurface loads, and similar processes of broad interest to the geosciences community. They will provide new constraints on the size of the "Hreppar block" and the breadth of diffuse shear and rifting zones along its southern and northern boundaries, respectively, which bears on the process of ridge propagation, and new constraints on the pattern of vertical crustal motion in central Iceland, with important implications for past and present glacial retreat, hydrological processes, surface erosion, magma movement, and other processes. The project should broaden our understanding of general lithospheric processes, bearing on many broad themes, including the rheology of oceanic lithosphere, present and past glacial loads, surface erosion, crustal and mantle dynamics, and volcano and earthquake hazards. CGPS in central Iceland is also facilitating expansion of the Icelandic seismic network, complementing ongoing InSAR and campaign-based GPS investigations, and providing new data for studies of weather and climate. The project is providing research experience for RESESS (Research Experience in Solid Earth Science for Students) interns.