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Abstract The stable isotope ratio of dissolved inorganic carbon (δ¹³C‐DIC) is a valuable tracer for investigating carbon cycling in aquatic environments. However, its potential remains underutilized due to limited data availability. Fewer than 15% of cruise samples are analyzed forδ¹³C‐DIC, as isotope analysis using isotope ratio mass spectrometry is labor‐intensive and restricted to onshore laboratories. We present over 3500δ¹³C‐DIC measurements from the 2023 Global Ocean Ship‐based Hydrographic Investigations Program A16N cruise in the North Atlantic. Notably, three‐quarters of these measurements were conducted onboard using a CO₂extraction device coupled with cavity ring‐down spectroscopy, a more efficient and cost‐effective method. This extensive dataset providesδ¹³C‐DIC values with spatial resolution comparable to other ocean carbonate chemistry and biogeochemical parameters. This dataset supports improved quantification of anthropogenic CO₂uptake and storage, and may facilitate the development of algorithms to estimateδ¹³C‐DIC in under sampled regions. 

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⁻¹strain 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.