Complex rupture and triggered aseismic creep during the August 14, 2021
Haiti earthquake from satellite geodesy
Abstract
The 2021 August 14 MW 7.2 Nippes, Haiti earthquake
occurred 75 km west of the epicenter of the 2010 Leogane earthquake
(Haiti) on the transpressive Caribbean - North America (CA-NA) plate
boundary. We present an updated fault map for Hispaniola and model
coseismic and early postseismic fault slip using Interferometric
Synthetic Aperture RADAR (InSAR) and pixel offsets. We find the
earthquake ruptured multiple segments of the Enriquillo-Plantain Garden
Fault Zone (EPGFZ). Slip occurred in two main sub-events separated by 60
km on either side of a restraining bend at Pic Macaya, with
~2.7 m of peak reverse-slip east of the bend. To the
west, slip jumps the restraining bend and further ruptures with
~1.3 meters of left-lateral slip. Afterslip in the four
days following the event occurred at shallow depth and adjacent to the
coseismic rupture areas and reached the surface to the east of Pic
Macaya.