Work

Constraining the Kinematics of the Victoria Microplate and the Northern Western Branch of the East African Rift System

Year: 2025

Type: article

Abstract: The fragmentation of continents results in microplates that rotate to accommodate the lateral propagation of bounding rifts. Yet, the relationships between microplate rotation rates, fault slip, and kinematics at propagating rift tips remain unknown. Here, we analyze new Global Navigation Satellite System (GNSS) data and structural geology data from the northern Western Branch of the East African Rift System that defines part of the boundary between the Nubian plate and the Victoria microplate. We resolve 0.0583 ± 0.0293°/Myr (6.48 ± 3.26 mm/yr) counterclockwise rotation of the Victoria microplate, consistent with previous studies, but with significant northwestward shift in the Euler pole relative to earlier work. Strain is largely localized on microplate‐bounding faults with 1.8–2.2 mm/yr slip rates, 7.2 × 10 −8 –1.28 × 10 −7 y −1 strain rates, NE‐directed extension, and oblique‐normal fault kinematics. Most GNSS velocities are consistent with block rigidity, but three sites in the NW region of the Victoria microplate indicate possible internal deformation.

Source: Geophysical Research Letters

DOI: 10.1029/2025gl116301