Iceland Geodynamics: Magma-Tectonic Interactions in South Iceland

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Short-term (less than about one million years) extensional processes in the world's mid-ocean ridge system are a challenge to observe and quantify due to their subaqueous setting. Magmatic segmentation of ridges leads to along strike variations in accommodating mechanisms (e.g., fault displacements may increase toward the end of magmatic segments, where there is little magma available to accommodate extension via dike intrusion), further complicating strain signals. The goal of this research is to study the complex four-dimensional crustal deformation field associated with the divergent plate boundary zone of Iceland using dense wide-aperture survey GPS and high-rate continuous GPS networks, much like the EarthScope Plate Boundary Observatory network, and builds on a six-year collaboration between the Pennsylvania State University, the University of Miami, the Nordic Volcanological Center, and the Icelandic Meteorological Office. This research team is investigating strain partitioning in South Iceland with the goal of better quantifying the temporal and spatial pattern of strain in the Eastern Volcanic Zone, Iceland. These studies will allow insight into the role of central volcanoes and magmatic segmentation of ridges in accommodating plate motion and the formation of crust, and lead to a better understanding of hazards related to central volcanoes and fissure swarms that have historically produced the largest volume lava flows on earth and caused short-term (on the order of years) changes in regional climate (e.g., the 1783-84 Lakagígar fissure eruption). This research project will increase understanding of rift kinematics; this class of plate boundary, which includes the world's mid-ocean ridges, is usually inaccessible for detailed geodetic study.