Strong Ground Motions near La Guaira during the 2026 Venezuela Earthquake: Effects of Rupture Dynamics and Slip Heterogeneity
Baoning Wu, David T. Sandwell, Rubi M. Garcia-Gonzalez, Jeremy Wing Ching Wong, Molly Zebker, & Alice-Agnes GabrielSubmitted August 30, 2026, SCEC Contribution #15367, 2026 SCEC Annual Meeting Poster #220
On June 24, 2026, an Mw7.5 earthquake occurred in northern Venezuela and caused catastrophic damage, with La Guaira among the most severely affected regions. We use 3D dynamic rupture simulations with linear slip-weakening friction to quantify how rupture kinematics and fault slip heterogeneity may amplify ground motions near La Guaira.
We compile coseismic slip models from multiple sources and calculate the corresponding static stress change distributions. We then use these distributions to construct initial stress and frictional strength fields that produce rupture propagation, final slip, and moment rate histories that are broadly consistent with the available kinematic models.
The simulations investigate two source processes that may enhance shaking near La Guaira. First, rupture propagates eastward for approximately 200 km from the Boconó Fault onto the San Sebastián Fault, placing La Guaira near the eastern endpoint of the rupture in the forward-directivity direction. Second, slip along the San Sebastián Fault increases from a local minimum near 67°W, close to the Tacagua Fault junction, to a maximum beneath La Guaira before tapering to zero east of the city near 66.7°W. In our models, reproducing this localized region of high slip requires strong spatial variations in initial stress and/or fault strength, which cause the rupture to accelerate and then decelerate across the La Guaira segment. These changes in rupture speed enhance seismic radiation and further increase simulated ground motion amplitudes near La Guaira.
Our results highlight the role of rupture propagation, changes in rupture speed, and slip heterogeneity in amplifying near-field ground motions beyond what may be inferred from peak fault slip alone. Local site conditions, such as coastal alluvial deposits and topography, may also have contributed to the amplified ground motions in La Guaira. Additional seismic and geodetic observations may help separate source, path, and site contributions to ground motions in La Guaira.
Key Words
dynamic rupture model, ground motions
Citation
Wu, B., Sandwell, D. T., Garcia-Gonzalez, R. M., Wong, J., Zebker, M., & Gabriel, A. (2026, 08). Strong Ground Motions near La Guaira during the 2026 Venezuela Earthquake: Effects of Rupture Dynamics and Slip Heterogeneity. Poster Presentation at 2026 SCEC Annual Meeting.
Related Projects & Working Groups
Ground Motions (GM)
