Investigation of focal mechanism and coseismic slip distribution for 2021 Haiti Mw7.2 earthquake

Objectives: For investigating the crustal deformation and its focal mechanism caused by the 2021 Haiti Mw7.2 earthquake, the coseismic deformation field of Haiti earthquake was obtained with D-InSAR technology according to the ascending and descending orbit data provided by Sentinel-1A satellite. Methods: Firstly, the observations are downsampled using uniform sampling methods. Then, fault parameters and optimal sliding distribution model are inversed using the Okada uniform elastic semi-infinite dislocation model. Finally, the displacements in three directions are calculated by the linear inversion data according to the forward model. The displacements in East, North, and Up directions are projected to the LOS of the satellite, thereby acquiring the deformation field of the radar LOS in the experiment area. Results: Results show that this earthquake is a thrust and left-lateral strike-slip event. The optimal fault dip angle is determined 58°. The strike is 265.5°. The slip angle is 50°. The epicenter location is 73.60°W， 18.43°N. The maximum sliding amount is 3.2m. Conclusions: The deformation of the earthquake is mainly uplift, and its value is 64cm, which is the result of the combined action of the main shock and aftershocks.