Modeling Present-Day Strain Accumulation and Fault Activity in The Northeastern Arabian Plate, Oman: A GPS Geodetic Analysis

ABSTRACT

Oman occupies a uniquely complex tectonic setting at the northeastern edge of the Arabian Plate, where all major plate boundary types converge. However, present-day intraplate deformation in the region remains poorly quantified. To address this, we processed GPS data from 57 continuous stations, mostly spanning from 2014 to 2023, to construct a high-resolution crustal strain map. We derived interseismic velocities within a stable Oman reference frame and used an elastic dislocation model to estimate fault coupling and slip rates on major structures. Velocity gradients were then interpolated to calculate continuous 2D strain rates. Our results reveal the highest tectonic activity along the northern Hawasina Thrust and the Masirah ophiolite front (Batain complex), where the crust undergoes WNW–ESE to NW–SE directed extension at rates up to 50 nanostrain/yr. In contrast, the central and southwestern parts of Oman experience crustal shortening (~20 nanostrain/yr) in NNW–SSE and NE–SW orientations. Significant shear strain (up to 20 nanostrain/yr) localizes along the northern segment of the Hawasina thrust sheet, which our modeling indicates is a normal fault with a ~11 km locking depth and a slip rate of ~4.5 mm/yr. This geodetically derived strain pattern correlates spatially with major structural traces, confirming that these faults currently accommodate regional tectonic loading. This study provides the first geodetic evidence for present-day strain localization on major faults within the northeastern Arabian Plate. The results establish a measurable basis for reassessing seismic hazard in a region often considered tectonically quiescent and demonstrate the value of dense GPS networks for modeling strain in slowly deforming continental interiors.