Contrasting active magma- and fault-dominated segments of the East African Rift through the synthesis of InSAR and GPS time series: Implications for rifting dynamics and hazards

University Of Hawaii, Honolulu

Investigators

Abstract

The East Africa Rift System (EARS) produces large damaging earthquakes, landslides, and volcanic hazards that threaten large developing populations that tend to be relatively less well-prepared with resilient infrastructure. Measuring how the surface of the Earth deforms in response to these natural processes allows scientists to better understand them and the associated hazards. The Global Positioning System (GPS) network in Africa is sparse, and network expansion has both political and financial challenges. Interferometric Synthetic Aperture Radar (InSAR) greatly complements GPS measurements with high spatial and temporal resolution imagery of ground deformation over the entire EARS, while avoiding the complications and costs associated with installing and maintaining instrumentation. Beyond volcano and tectonic applications, combining GPS and InSAR measurements of ground deformation also allows scientists to monitor anthropogenic activities such as groundwater extraction. Understanding both natural and anthropogenic-related deformation is important for local communities for better water management, improved planning and development of infrastructure, and protection of natural environments. The objective of this project is to produce precise maps of temporally and spatially dense crustal deformation time series across the central EARS documenting tectonic, volcanic, and anthropogenic related deformation signals. This will involve synthesizing and integrating GPS data collected by previously funded GeoPRISMS projects with InSAR displacement time series across the central section of the EARS. These data will allow for improved characterization and comparisons of distributions of strain between the likely plume-controlled eastern segment and the likely fault-controlled western segment that branches around the Tanzania Craton, placing these observations in the context of the geologic history and pre-existing structures. Results from this work will provide reliable measurements of crustal deformation to support a diverse range of research questions related to rift dynamics. Additionally, it will provide critical constraints for modeling rift initiation and evolution on the central, eastern, and western segments of the EARS, with extended applications to anthropogenic deformation This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.