The Punta Montalva Fault is an active left-lateral strike-slip fault that slipped during the 2019-2020 Puerto Rico seismic sequence. Not much is known about the structure, segmentation, and spatial extent of the fault as it is obscured under thick vegetation and is difficult to access. This study used high-resolution topographic data to map the Punta Montalva Fault’s structure, segmentation, and spatial extent and conduct vertical differencing of topography to determine if slip is detectable along the fault from 2004 to 2018. A 0.5 m resolution bare-earth digital elevation model (DEM) derived from a 2018 airborne light detection and ranging (LiDAR) survey and a 1 m resolution 2018 DEM was used to map the Punta Montalva Fault from Punta Montalva to Ensenada Las Pardas. High-resolution mapping revealed that the Punta Montalva Fault is comprised of three main fault segments on the surface and two fault scarps in they bathymetry. The fault segments on the surface and bathymetry illustrate both strike-slip and normal fault movement. The DEM revealed scarps, dragged and cut layers, and a duplex structure. The total length of the fault segments exposed on the surface is approximately 2.67 km long. However, if the Punta Montalva Fault is continuous beneath the surface, its total fault length would be approximately 7.97 km long. These factors are beneficial to determine the Punta Montalva Fault’s surface rupture length.

Two LiDAR datasets from 2004 and 2018 were used to conduct vertical differencing of topography along the Punta Montalva Fault from Punta Montalva to Ensenada Las Pardas. Both the 2004 and 2018 LiDAR datasets were processed into digital terrain models (DTMs) and then subtracted from one another to visualize the vertical change in topography that has occurred in the 14 years along the Punta Montalva Fault. Vertical differencing results along the Punta Montalva Fault were unconclusive due to poor quality of the 2004 DEM.