The 1819 Allah-Bund earthquake (ABE) that occurred in the north-western part of the Kachchh rift, India, was a deadliest intraplate earthquake of the nineteenth century. In this work, we have used WGM 2012 global gravity model data to understand the tectonic framework in the epicentral zone of the 1819 ABE and surrounding regions. Total horizontal gradient analysis of the Bouguer anomaly (BA) is carried out to map major lineaments in the study area. The logarithmic amplitude spectra of the BA provide the average depth of 13 km between the interface of the upper crust and the basement while basement-sediment interface is found at 1.6 km. The low-pass filter anomaly of cut-off wavelength of 100 km is considered as the regional anomaly. The residual anomaly shows high value with a NW–SE trend which is similar to the trace of Allah-Bund (AB) on the surface. The upper crustal geometry of the region is provided for the first time by performing 2.5D forward gravity modelling along two profiles. These are constrained by seismological and well data. Our present model reveals that the upper crustal thickness increases towards the AB. Inversion of the BA reveals the NW dipping Moho in the study area. The basement is undulating, which is uplifted by 1–2 km over the AB. We also tried to explain the seismicity in the study area. The present study provided the first geophysical evidence of the ABF, and it is inferred that the fault is shallow in nature, dipping in the SW direction.
