Tectonics in Hispaniola (Caribbean)


Haiti has been struck by two devastating earthquakes in 2010 and 2021 killing over 200000-250000 people combined. Majority of the faults in Haiti and Dominican Republic are not well geodetically constrained due to very few GPS observations. My aim is to get InSAR constraints on the slip rates of the EPGFZ and SOF faults in Hispaniola. This will help in understanding the fault mechanics and locate regions with higher earthquake risks.

Coseismic and early postseismic slip after the 2021 Haiti Earthquake (submitted to GRL)

Bayesian studies for earthquake fault parameters estimation


  • Modeling faults as non-planar surfaces - I developed a technique to estimate non-planar fault geometries simultaneously with the spatially-variable slip from geodetic data (InSAR/ optical / GNSS). The technique includes parametrization of non-planar fault geometries (varying fault geometries both in along-strike and down-dip directions) using only a few parameters, using state-of-the-art method SMC for sampling the posterior probability density and is exemplified using a few synthetic tests. https://doi.org/10.1029/2020JB020441

Varying fault dip in down-dip direction

in along-strike direction


  • Improved fault parameter estimation - Studied small to moderate magnitude earthquakes using InSAR data. Used a priori information on the moment magnitude and aftershock locations to improve the fault parameters estimation. Studied the bias in the estimated Coulomb Failure Stress changes due to these improvements.
    https://doi.org/10.1093/gji/ggx551
    https://doi.org/10.1785/0120140289

2006 Fukuoka earthquake, Kyushu, Japan (Mw 6.6)


2004 Tabuk earthquake, Saudi Arabia (Mw 5.1)



Mechanical properties of conjugate compliant fault-zones in Makran accretionary prism


Co-seismic stress perturbations due to the 2013 Balochistan earthquake caused some anomalous displacements across some nearby conjugate strike-slip faults observed using InSAR. With finite element modeling, these anomalous deformations were explained as the elastic response of compliant fault zones surrounding the strike-slip faults due to the earthquake.

Geological map of fault offsets

courtesy: Jon Harrington

InSAR observation of anomalous deformations

Finite-element modeling set up


Active layer thickness estimation in continuous permafrost regions of Alaska using InSAR


  • Permafrosts are perennially frozen ground - at least for 2 years. The soil column called the active layer above the frozen ground thaws in the summer and freezes in the winter. We can capture the deformation related to active layer thawing using InSAR. Then using the deformation time-series, I estimated the active layer thickness and the inter-annual subsidence rate in the region. Measuring these parameters are important to understand the response of permafrost system to global warming (climate change).

Pattern of deformation - thawing and freezing of active layer

InSAR data and modeled displacements related to thawing

modeled inter-annual subsidence rate

modeled active layer thickness