The 2021 Mw 7.2 Haiti Earthquake: Rupture of a Blind Thrust Fault
Revealed by Space Geodetic Observations
Abstract
On 14 August 2021, a large earthquake struck the southern region of
Haiti. The epicenter of this earthquake is located relatively close to
the Enriquillo–Plantain Garden Fault (EPGF) zone, a major active fault
with a strike-slip mechanism in the southern part of Hispaniola. The
Sentinel-1 data is utilized to investigate the seismogenic fault
responsible for the 2021 Haiti earthquake. The Bayesian inversion and
the aftershock distribution indicated that the mainshock ruptured a
north-dipping fault, buried at a depth of ~10.4 km from
the earth’s surface. The preferred slip model showed that the rupture
did not reach the surface and was confined at a depth of
~8 km to ~33 km. These characteristics
are inconsistent with those of the EPGF, indicating that the EPGF is
probably not the seismogenic fault responsible for the 2021 Haiti
earthquake. Instead, results showed that the 2021 Haiti earthquake
ruptured an unmapped blind fault.